Hypotension
Conditions
Keywords
Decision support, Decision Support Systems, Clinical, Decision Support Techniques, Hypotension, Intraoperative Hypotension, Acute Kidney Injury, Postoperative Mortality, Blood Pressure
Brief summary
The purpose of this study is to determine whether a decision support system can improve the adherence to thresholds for low blood pressure by anesthesia providers, which in turn prevents their patients from having organ injury.
Detailed description
Blood pressure management is an important part of anesthesia. Many factors contribute to a change in blood pressure during a surgical procedure, such as blood loss, manipulation by surgeons, and there are several mechanisms through which anesthesia itself changes blood pressure. Although a high blood pressure also occurs during anesthesia, most of these factors lower a patient's blood pressure. When a patient's blood pressure becomes too low, the internal organs become at risk of receiving not enough blood (low perfusion or hypoperfusion). This low perfusion state can result in organ damage (ischemia) because of an insufficient supply of oxygen and glucose. Hence the important task of anesthesia providers to maintain the blood pressure of patients, using a wide range of drugs and other interventions. A big challenge in blood pressure management is to know when a low blood pressure indeed results in low perfusion of organs. There is a large variation between patients in how susceptible they are to low blood pressure, as well as a difference between the organs in how easily they are damaged because of low perfusion. Elder patients, or patients with preexisting hypertension, heart problems or other cardiovascular diseases are more prone to a low blood pressure and are more likely to develop organ ischemia when there is a low blood pressure. The kidneys, the heart and the brain are the organs that are most at risk of organ damage. As one cannot measure the perfusion states of individual organs in individual patients, it is very difficult to know 'how low to go' with a patient's blood pressure. Recent studies have used large datasets of patients to demonstrate that there is statistical association between low blood pressure during surgery and various types of organ injury. As patients are already treated for low blood pressure by anesthesia providers, this suggests that patients have low organ perfusion states despite the current treatment standards. A patient's blood pressure is not simply a dial that can be adjusted to a specific level. Finding the right level of interventions can be difficult in some patients. Consequently, lower blood pressures are common in anesthesia, even with the current standards of blood pressure management. In this proposed study the investigators will implement two forms of decision support to assist anesthesia providers in blood pressure management. The decision support aims to educate anesthesia providers about the risks of low blood pressures in direct relation to the patients that they treat. One form of decision support will provide automated notifications through pagers and through the anesthesia information management system. These automated notifications pop up when the patient's blood pressure drops below a level that is associated with a risk of organ injury, and thus alerts the anesthesia provider of the blood pressure and its associated risk. The second form of decision support will send a postoperative email the day after the procedure when the patient has had a low blood pressure for particular duration. This email then provides feedback to the anesthesia provider by informing them of the increased risks of organ injury that are associated with that low blood pressure. The study will look at both a change in patient outcome and a change in blood pressure management and will be performed at the Vanderbilt University Medical Center (VUMC). The change in patient outcome will primarily be studied through the occurrence of acute kidney injury in the first days following the procedure at the VUMC. The change in blood pressure management (provider behavior) will be studied by observing the depth and duration of low pressures during anesthesia, and the number of interventions that have been used to treat the blood pressure. Patient outcome will be studied by comparison of a baseline phase - before the decision support is implemented and uses historic data- and the intervention phase - the period during which the intervention is active. Only routinely collected clinical data will be used for these analyses: no additional data collection is required. As it is impossible to know which form of decision support will be the most effective, the first three months of the intervention period will be a 'nested cluster-randomized trial'. The anesthesia providers (not the patients) will be randomized to either the automated notifications or the feedback emails. After three months all anesthesia providers will receive both forms of decision support for the remainder of the intervention period. The reason why anesthesia providers are randomized only during the first three months is that cross-over or contamination between the two groups is expected. This contamination could make it impossible to study the effect of the decision support on patient outcome, as there will be no longer any difference between the study groups.
Interventions
PROCEDURENon-cardiac surgery
Any surgical intervention that is not aimed at surgical correction of the heart
DRUGPropofol
Anesthetic drug used to maintain general anesthesia
DRUGSevoflurane
Anesthetic drug used to maintain general anesthesia
DRUGDesflurane
Anesthetic drug used to maintain general anesthesia
PROCEDUREAttending real-time decision support
Near real-time decision support elements will notify the attending anesthesiologists of a blood pressure drop below the threshold for intraoperative hypotension (mean arterial pressure below 60 mmHg). The notification is presented through the pager system. The page will also display the associated increased risk of organ injury due to organ ischemia.
PROCEDUREIn-room real-time decision support
Near real-time decision support elements will notify the in-room anesthesia provider of a blood pressure drop below the threshold for intraoperative hypotension (mean arterial pressure below 60 mmHg). The notification is presented through the anesthesia information management system. The decision support system will display the associated increased risk of organ injury due to organ ischemia.
PROCEDURECentral neuraxial anesthesia
Regional anesthesia effectuated through the placement of local anesthetics around the nerves of the central nervous system, e.g. spinal anesthesia and epidural anesthesia.
PROCEDUREAttending feedback emails
Attending anesthesiologists will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension (mean arterial pressure below 60 mmHg or lower for a particular duration) that is associated with an increased risk of organ injury due to organ ischemia.
PROCEDUREIn-room provider feedback emails
In-room anesthesia providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension (mean arterial pressure below 60 mmHg or lower for a particular duration) that is associated with an increased risk of organ injury due to organ ischemia.
The anesthesia electronic record keeping system
The data warehouse that is used to gather perioperative data and create user reports. In this instance the PDW will be used to send the postoperative feedback emails.
PROCEDUREGeneral anesthesia
Any anesthetic drugs that are used to induce general anesthesia above the level of sedation.
DEVICEPager system
The mobile pager system through which alerts can be sent
DRUGIsoflurane
Anesthetic drug used to maintain general anesthesia
DRUGEphedrine
Cardiovascular drug used to treat intraoperative hypotension
DRUGPhenylephrine
Cardiovascular drug used to treat intraoperative hypotension
DRUGNorepinephrine
Cardiovascular drug used to treat intraoperative hypotension
DRUGEpinephrine
Cardiovascular drug used to treat intraoperative hypotension
DRUGDobutamine
Cardiovascular drug used to treat intraoperative hypotension
DRUGDopamine
Cardiovascular drug used to treat intraoperative hypotension
DRUGIsoproterenol
Cardiovascular drug used to treat intraoperative hypotension
DRUGMilrinone
Cardiovascular drug used to treat intraoperative hypotension
DRUGAtropine
Cardiovascular drugs used to treat intraoperative hypotension
DRUGGlycopyrrolate
Cardiovascular drug used to treat intraoperative hypotension
DRUGVasopressin
Cardiovascular drug used to treat intraoperative hypotension
DRUGTerlipressin
Cardiovascular drug used to treat intraoperative hypotension
DRUGSodium Chloride 0.9%
Intravenous fluid used to treat intraoperative hypotension
DRUGRinger's lactate
Intravenous fluid used to treat intraoperative hypotension
DRUGHydroxyethyl starch solutions
Intravenous fluid used to treat intraoperative hypotension
DRUGFresh Frozen Plasma
Intravenous fluid used to treat intraoperative hypotension
Intravenous fluid used to treat intraoperative hypotension
DRUGAlbumin solutions
Intravenous fluid used to treat intraoperative hypotension
DRUGPlasma-Lyte
Intravenous fluid used to treat intraoperative hypotension
DRUGLidocaine
Local anesthetic used for central neuraxial anesthesia.
DRUGBupivacaine
Local anesthetic used for central neuraxial anesthesia.
DRUGLevobupivacaine
Local anesthetic used for central neuraxial anesthesia.
DRUGRopivacaine
Local anesthetic used for central neuraxial anesthesia.
DRUGMepivacaine
Local anesthetic used for central neuraxial anesthesia.
DRUGTetracaine
Local anesthetic used for central neuraxial anesthesia.
DRUGPrilocaine
Local anesthetic used for central neuraxial anesthesia.
DRUGProcaine
Local anesthetic used for central neuraxial anesthesia.
DRUGChloroprocaine
Local anesthetic used for central neuraxial anesthesia.
DRUGBenzocaine
Local anesthetic used for central neuraxial anesthesia.
DRUGArticaine
Local anesthetic used for central neuraxial anesthesia.
Sponsors
UMC Utrecht
Vanderbilt University Medical Center
Study design
Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
It is an interrupted time-series of a decision support package intervention that aims to study the the effect of the decision support package on patient outcome. The effects of the individual decision support components of the package on healthcare provider behavior will be studied in a nested cluster-randomized trial: in the first month the attending anesthesiologists will be randomized to near-realtime notifications or feedback emails; in the second month in-room providers will be randomized to near-realtime notifications or feedback emails. Starting month four all providers will receive both near-realtime notifications and feedback emails.
Eligibility
Sex/Gender
ALL
Age
60 Years to 100 Years
Healthy volunteers
No
Inclusion criteria
* 60 years and older * Inpatients * Scheduled for a non-cardiac surgical procedure under general or central neuraxial anesthesia
Exclusion criteria
* Pre-existing end-stage renal disease: operationalized as a preoperative need for dialysis * The following surgical procedures: renal surgery, cardiac surgery, organ transplantation, ophthalmic surgery, endoscopic gastrointestinal procedures, and (interventional) radiologic procedures. * small non-invasive or minimally-invasive procedures will also be excluded, operationalized as excluding procedures with a surgical time of less than twenty minutes.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postoperative Acute Kidney Injury | Within 7 days after surgery | Postoperative Acute Kidney Injury (AKI), Stage I or higher according to the KDIGO criteria (Kidney Disease: Improving Global Outcomes). The staging will be based on serum creatinine values, as documentation of urine output is probably not sufficiently accurate. This will be the primary outcome for the Vanderbilt University Medical Center. The creatinine measurements are part of routine clinical care. Therefore, absence of creatinine postoperative measurements are considered to be 'no suspicion of kidney injury'. KDIGO defines AKI as any of the following: Increase in serum creatinine by 0.3mg/dL or more within 48 hours or Increase in serum creatinine to 1.5 times baseline or more within the last 7 days or Urine output less than 0.5 mL/kg/h for 6 hours. Stage 1 is 1.5-9x baseline or \>0.3 increase; Stage 2 is 2-2.9x baseline; Stage 3 is 3x baseline, or increase to \> 4, or initiation of renal replacement therapy. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| In-hospital Mortality | All postoperative days during a single hospital admission, expected median of 5 days | Hospital mortality rate during a single hospital admission after the surgery |
| Postoperative Acute Kidney Injury Stage 2 | Within 7 days after surgery | Postoperative Acute Kidney Injury (AKI), Stage II or higher according to the KDIGO criteria (Kidney Disease: Improving Global Outcomes). The staging will be based on serum creatinine values, as documentation of urine output is probably not sufficiently accurate. The creatinine measurements are part of routine clinical care. Therefore, absence of creatinine postoperative measurements are considered to be 'no suspicion of kidney injury'. KDIGO defines AKI as any of the following: Increase in serum creatinine by 0.3mg/dL or more within 48 hours or Increase in serum creatinine to 1.5 times baseline or more within the last 7 days or Urine output less than 0.5 mL/kg/h for 6 hours. Stage 1 is 1.5-9x baseline or \>0.3 increase; Stage 2 is 2-2.9x baseline; Stage 3 is 3x baseline, or increase to \> 4, or initiation of renal replacement therapy. |
| Postoperative Rise in Creatinine Levels | Within 7 days after surgery | Absolute values for serum creatinine before and after surgery will be compared. When multiple postoperative creatinine measurements are made, the maximum difference is reported. |
| Incidence of a MAP < 60 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Incidence of a mean arterial pressure (MAP) \< 60 mmHg during anesthesia for 1 minute or more. |
| Incidence of a MAP < 55 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Incidence of a mean arterial pressure (MAP) \< 55 mmHg during anesthesia for 1 minute or more. |
| Incidence of a MAP < 50 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Incidence of a mean arterial pressure (MAP) \< 50 mmHg during anesthesia for 1 minute or more. |
| Incidence of a MAP < 60 mmHg for > 10 Minutes | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Incidence of a mean arterial pressure (MAP) \< 60 mmHg for a cumulative duration of all hypotensive episodes of more than 10 minutes during the anesthetic phase of the procedure. |
| Incidence of a MAP < 55 mmHg for > 10 Minutes | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Incidence of a mean arterial pressure (MAP) \< 55 mmHg for a cumulative duration of all hypotensive episodes of more than 10 minutes during the anesthetic phase of the procedure. |
| Intraoperative Administration of Intravenous Fluids | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Total amount (mL) of intravenous fluids (as defined under interventions) administered during the surgical procedure. |
| Incidence of a MAP < 50 mmHg for > 10 Minutes | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Incidence of a mean arterial pressure (MAP) \< 50 mmHg for a cumulative duration of all hypotensive episodes of more than 10 minutes during the anesthetic phase of the procedure. |
| Incidence of a MAP < 60 mmHg for > 20 Minutes | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Incidence of a mean arterial pressure (MAP) \< 60 mmHg for a cumulative duration of all hypotensive episodes of more than 20 minutes during the anesthetic phase of the procedure. |
| Incidence of a MAP < 55 mmHg for > 20 Minutes | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Incidence of a mean arterial pressure (MAP) \< 55 mmHg for a cumulative duration of all hypotensive episodes of more than 20 minutes during the anesthetic phase of the procedure. |
| Incidence of a MAP < 50 mmHg for > 20 Minutes | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Incidence of a mean arterial pressure (MAP) \< 50 mmHg for a cumulative duration of all hypotensive episodes of more than 20 minutes during the anesthetic phase of the procedure. |
| Depth and Duration of Intraoperative Hypotension - Threshold MAP 75 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis. |
| Depth and Duration of Intraoperative Hypotension - Threshold MAP 70 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis. |
| Depth and Duration of Intraoperative Hypotension - Threshold MAP 65 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis. |
| Depth and Duration of Intraoperative Hypotension - Threshold MAP 60 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis. |
| Average Use of Cardiovascular Drugs: Glycopyrrolate | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in \<1% of cases are not reported, as the average dosage would be meaningless. |
| Depth and Duration of Intraoperative Hypotension - Threshold MAP 55 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis. |
| 30-day Mortality | 30 days after surgery | Vanderbilt University Medical Center: combination of in-hospital mortality and 'alive-index' (which checks for visits to the hospital in the electronic healthcare record as indication of being alive at 30 days) |
| Estimated Intraoperative Blood Loss | During the surgical procedure: an expected average of 2 hours | The estimated blood loss in mL during the surgical procedure |
| Time to Discharge Readiness at the Postanesthesia Care Unit (PACU) | A specific time frame on the day of surgery: from the start of admission to the PACU to discharge from the PACU, an expected average of 4 hours | The time from arriving at the postanesthesia care unit (PACU) until the time the patient is considered ready for discharge (in minutes). |
| Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Average concentrations of propofol infusion rates during MAP \< 65 mmHg episodes |
| Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Average concentrations of propofol infusion rates during MAP \< 60 mmHg episodes |
| Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Average concentrations of propofol infusion rates during MAP \< 55 mmHg episodes |
| Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Average concentrations of propofol infusion rates during MAP \< 50 mmHg episodes |
| Average Use of Cardiovascular Drugs: Ephedrine | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in \<1% of cases are not reported, as the average dosages would be meaningless. |
| Average Use of Cardiovascular Drugs: Phenylephrine | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in \<1% of cases are not reported, as the average dosage would be meaningless. |
| Average Use of Cardiovascular Drugs: Epinephrine | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in \<1% of cases are not reported, as the average dosage would be meaningless. |
| Average Use of Cardiovascular Drugs: Norepinephrine | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in \<1% of cases are not reported, as the average dosage would be meaningless. |
| Timing of Cardiovascular Drugs for MAP < 65 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 60 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP. |
| Timing of Cardiovascular Drugs for MAP < 60 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 60 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP. |
| Timing of Cardiovascular Drugs for MAP < 55 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 55 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP. |
| Timing of Cardiovascular Drugs for MAP < 50 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 50 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP. |
| Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Average concentrations of inhalational anesthesia during MAP \< 65 mmHg episodes |
| Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Average concentrations of inhalational anesthesia during MAP \< 60 mmHg episodes |
| Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Average concentrations of inhalational anesthesia during MAP \< 55 mmHg episodes |
| Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Average concentrations of inhalational anesthesia during MAP \< 50 mmHg episodes |
| Depth and Duration of Intraoperative Hypotension - Threshold MAP 50 mmHg | During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours | Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Usual Care Group The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm). | 17,463 |
| Hypotension Decision Support The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails.
Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider.
All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia. | 4,972 |
| Total | 22,435 |
Baseline characteristics
| Characteristic | Usual Care Group | Total | Hypotension Decision Support |
|---|---|---|---|
| Age, Continuous | 68 years | 68 years | 68 years |
| AKI risk based on IOH depth and duration AKI risk: high | 2867 Participants | 3544 Participants | 677 Participants |
| AKI risk based on IOH depth and duration AKI risk: mild | 6622 Participants | 8607 Participants | 1985 Participants |
| AKI risk based on IOH depth and duration AKI risk: moderate | 4290 Participants | 5426 Participants | 1136 Participants |
| AKI risk based on IOH depth and duration AKI risk: none | 3684 Participants | 4858 Participants | 1174 Participants |
| ASA Class ASA Class 1 | 74 Participants | 90 Participants | 16 Participants |
| ASA Class ASA Class 2 | 3109 Participants | 3874 Participants | 765 Participants |
| ASA Class ASA Class 3 | 12344 Participants | 15922 Participants | 3578 Participants |
| ASA Class ASA Class 4 | 1885 Participants | 2470 Participants | 585 Participants |
| ASA Class ASA Class 5 | 51 Participants | 79 Participants | 28 Participants |
| Body Mass Index | 28 kg/m^2 | 28 kg/m^2 | 28 kg/m^2 |
| Cardiac disease | 4843 Participants | 6332 Participants | 1489 Participants |
| Diabetes Mellitus | 4456 Participants | 5752 Participants | 1296 Participants |
| Hypertension | 11403 Participants | 14751 Participants | 3348 Participants |
| Peripheral vascular disease | 1947 Participants | 2543 Participants | 596 Participants |
| Procedure duration | 201 minutes | 200 minutes | 196 minutes |
| Procedure urgency Elective surgery | 16452 Participants | 21083 Participants | 4631 Participants |
| Procedure urgency Emergency surgery | 1011 Participants | 1352 Participants | 341 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 18 Participants | 22 Participants | 4 Participants |
| Race (NIH/OMB) Asian | 113 Participants | 149 Participants | 36 Participants |
| Race (NIH/OMB) Black or African American | 1111 Participants | 1491 Participants | 380 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 650 Participants | 854 Participants | 204 Participants |
| Race (NIH/OMB) White | 15571 Participants | 19919 Participants | 4348 Participants |
| Region of Enrollment United States | 17463 participants | 22435 participants | 4972 participants |
| Renal Disease | 1432 Participants | 1943 Participants | 511 Participants |
| Sex: Female, Male Female | 7731 Participants | 9872 Participants | 2141 Participants |
| Sex: Female, Male Male | 9707 Participants | 12529 Participants | 2822 Participants |
| Surgical service ENT | 1891 Participants | 2419 Participants | 528 Participants |
| Surgical service General surgery | 3638 Participants | 4639 Participants | 1001 Participants |
| Surgical service Gynecology | 113 Participants | 143 Participants | 30 Participants |
| Surgical service Neurosurgery | 2138 Participants | 2760 Participants | 622 Participants |
| Surgical service Orthopedic surgery | 4283 Participants | 5505 Participants | 1222 Participants |
| Surgical service Plastic surgery | 776 Participants | 971 Participants | 195 Participants |
| Surgical service Thoracic surgery | 1056 Participants | 1366 Participants | 310 Participants |
| Surgical service Urology | 2648 Participants | 3426 Participants | 778 Participants |
| Surgical service Vascular surgery | 920 Participants | 1206 Participants | 286 Participants |
| Type of anesthesia Central neuraxial anesthesia | 412 Participants | 634 Participants | 222 Participants |
| Type of anesthesia General anesthesia | 17051 Participants | 21801 Participants | 4750 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 534 / 17,463 | 158 / 4,972 |
| other Total, other adverse events | 0 / 17,463 | 0 / 4,972 |
| serious Total, serious adverse events | 1,811 / 17,463 | 541 / 4,972 |
Outcome results
Primary
Postoperative Acute Kidney Injury
Postoperative Acute Kidney Injury (AKI), Stage I or higher according to the KDIGO criteria (Kidney Disease: Improving Global Outcomes). The staging will be based on serum creatinine values, as documentation of urine output is probably not sufficiently accurate. This will be the primary outcome for the Vanderbilt University Medical Center. The creatinine measurements are part of routine clinical care. Therefore, absence of creatinine postoperative measurements are considered to be 'no suspicion of kidney injury'. KDIGO defines AKI as any of the following: Increase in serum creatinine by 0.3mg/dL or more within 48 hours or Increase in serum creatinine to 1.5 times baseline or more within the last 7 days or Urine output less than 0.5 mL/kg/h for 6 hours. Stage 1 is 1.5-9x baseline or \>0.3 increase; Stage 2 is 2-2.9x baseline; Stage 3 is 3x baseline, or increase to \> 4, or initiation of renal replacement therapy.
Time frame: Within 7 days after surgery
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Usual Care Group | Postoperative Acute Kidney Injury | AKI stage I or greater | 1333 Participants |
| Usual Care Group | Postoperative Acute Kidney Injury | No AKI - Confirmed by measurement | 9670 Participants |
| Usual Care Group | Postoperative Acute Kidney Injury | No postoperative creatinine measurement | 4621 Participants |
| Hypotension Decision Support | Postoperative Acute Kidney Injury | AKI stage I or greater | 372 Participants |
| Hypotension Decision Support | Postoperative Acute Kidney Injury | No AKI - Confirmed by measurement | 2785 Participants |
| Hypotension Decision Support | Postoperative Acute Kidney Injury | No postoperative creatinine measurement | 1171 Participants |
Secondary
30-day Mortality
Vanderbilt University Medical Center: combination of in-hospital mortality and 'alive-index' (which checks for visits to the hospital in the electronic healthcare record as indication of being alive at 30 days)
Time frame: 30 days after surgery
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). For a large group of patients no mortality information was available.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | 30-day Mortality | 511 Participants |
| Hypotension Decision Support | 30-day Mortality | 143 Participants |
Secondary
Average Use of Cardiovascular Drugs: Ephedrine
Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in \<1% of cases are not reported, as the average dosages would be meaningless.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). In addition, only patients that actually received any ephedrine are analyzed.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Average Use of Cardiovascular Drugs: Ephedrine | 20 mg |
| Hypotension Decision Support | Average Use of Cardiovascular Drugs: Ephedrine | 15 mg |
Secondary
Average Use of Cardiovascular Drugs: Epinephrine
Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in \<1% of cases are not reported, as the average dosage would be meaningless.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). In addition, only patients that actually received any epinephrine are analyzed.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Average Use of Cardiovascular Drugs: Epinephrine | 1.00 mg |
| Hypotension Decision Support | Average Use of Cardiovascular Drugs: Epinephrine | 0.70 mg |
Secondary
Average Use of Cardiovascular Drugs: Glycopyrrolate
Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in \<1% of cases are not reported, as the average dosage would be meaningless.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). In addition, only patients that actually received any glycopyrrolate are analyzed.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Average Use of Cardiovascular Drugs: Glycopyrrolate | 0.40 mg |
| Hypotension Decision Support | Average Use of Cardiovascular Drugs: Glycopyrrolate | 0.40 mg |
Secondary
Average Use of Cardiovascular Drugs: Norepinephrine
Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in \<1% of cases are not reported, as the average dosage would be meaningless.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). In addition, only patients that actually received any norepinephrine are analyzed.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Average Use of Cardiovascular Drugs: Norepinephrine | 0.62 mg |
| Hypotension Decision Support | Average Use of Cardiovascular Drugs: Norepinephrine | 0.70 mg |
Secondary
Average Use of Cardiovascular Drugs: Phenylephrine
Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in \<1% of cases are not reported, as the average dosage would be meaningless.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). In addition, only patients that actually received any phenylephrine are analyzed.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Average Use of Cardiovascular Drugs: Phenylephrine | 0.90 mg |
| Hypotension Decision Support | Average Use of Cardiovascular Drugs: Phenylephrine | 1.30 mg |
Secondary
Depth and Duration of Intraoperative Hypotension - Threshold MAP 50 mmHg
Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Depth and Duration of Intraoperative Hypotension - Threshold MAP 50 mmHg | 19 mmHg*minute |
| Hypotension Decision Support | Depth and Duration of Intraoperative Hypotension - Threshold MAP 50 mmHg | 19 mmHg*minute |
Secondary
Depth and Duration of Intraoperative Hypotension - Threshold MAP 55 mmHg
Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Depth and Duration of Intraoperative Hypotension - Threshold MAP 55 mmHg | 23 mmHg*minute |
| Hypotension Decision Support | Depth and Duration of Intraoperative Hypotension - Threshold MAP 55 mmHg | 23 mmHg*minute |
Secondary
Depth and Duration of Intraoperative Hypotension - Threshold MAP 60 mmHg
Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Depth and Duration of Intraoperative Hypotension - Threshold MAP 60 mmHg | 57 mmHg*minute |
| Hypotension Decision Support | Depth and Duration of Intraoperative Hypotension - Threshold MAP 60 mmHg | 52 mmHg*minute |
Secondary
Depth and Duration of Intraoperative Hypotension - Threshold MAP 65 mmHg
Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Depth and Duration of Intraoperative Hypotension - Threshold MAP 65 mmHg | 96 mmHg*minute |
| Hypotension Decision Support | Depth and Duration of Intraoperative Hypotension - Threshold MAP 65 mmHg | 86 mmHg*minute |
Secondary
Depth and Duration of Intraoperative Hypotension - Threshold MAP 70 mmHg
Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Depth and Duration of Intraoperative Hypotension - Threshold MAP 70 mmHg | 273 mmHg*minute |
| Hypotension Decision Support | Depth and Duration of Intraoperative Hypotension - Threshold MAP 70 mmHg | 235 mmHg*minute |
Secondary
Depth and Duration of Intraoperative Hypotension - Threshold MAP 75 mmHg
Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Depth and Duration of Intraoperative Hypotension - Threshold MAP 75 mmHg | 485 mmHg*minute |
| Hypotension Decision Support | Depth and Duration of Intraoperative Hypotension - Threshold MAP 75 mmHg | 417 mmHg*minute |
Secondary
Estimated Intraoperative Blood Loss
The estimated blood loss in mL during the surgical procedure
Time frame: During the surgical procedure: an expected average of 2 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Estimated Intraoperative Blood Loss | 100 mL |
| Hypotension Decision Support | Estimated Intraoperative Blood Loss | 75 mL |
Secondary
Incidence of a MAP < 50 mmHg
Incidence of a mean arterial pressure (MAP) \< 50 mmHg during anesthesia for 1 minute or more.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Incidence of a MAP < 50 mmHg | 7781 Participants |
| Hypotension Decision Support | Incidence of a MAP < 50 mmHg | 2196 Participants |
Secondary
Incidence of a MAP < 50 mmHg for > 10 Minutes
Incidence of a mean arterial pressure (MAP) \< 50 mmHg for a cumulative duration of all hypotensive episodes of more than 10 minutes during the anesthetic phase of the procedure.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Incidence of a MAP < 50 mmHg for > 10 Minutes | 1159 Participants |
| Hypotension Decision Support | Incidence of a MAP < 50 mmHg for > 10 Minutes | 326 Participants |
Secondary
Incidence of a MAP < 50 mmHg for > 20 Minutes
Incidence of a mean arterial pressure (MAP) \< 50 mmHg for a cumulative duration of all hypotensive episodes of more than 20 minutes during the anesthetic phase of the procedure.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Incidence of a MAP < 50 mmHg for > 20 Minutes | 304 Participants |
| Hypotension Decision Support | Incidence of a MAP < 50 mmHg for > 20 Minutes | 85 Participants |
Secondary
Incidence of a MAP < 55 mmHg
Incidence of a mean arterial pressure (MAP) \< 55 mmHg during anesthesia for 1 minute or more.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Incidence of a MAP < 55 mmHg | 10991 Participants |
| Hypotension Decision Support | Incidence of a MAP < 55 mmHg | 3045 Participants |
Secondary
Incidence of a MAP < 55 mmHg for > 10 Minutes
Incidence of a mean arterial pressure (MAP) \< 55 mmHg for a cumulative duration of all hypotensive episodes of more than 10 minutes during the anesthetic phase of the procedure.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Incidence of a MAP < 55 mmHg for > 10 Minutes | 3181 Participants |
| Hypotension Decision Support | Incidence of a MAP < 55 mmHg for > 10 Minutes | 759 Participants |
Secondary
Incidence of a MAP < 55 mmHg for > 20 Minutes
Incidence of a mean arterial pressure (MAP) \< 55 mmHg for a cumulative duration of all hypotensive episodes of more than 20 minutes during the anesthetic phase of the procedure.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Incidence of a MAP < 55 mmHg for > 20 Minutes | 1223 Participants |
| Hypotension Decision Support | Incidence of a MAP < 55 mmHg for > 20 Minutes | 284 Participants |
Secondary
Incidence of a MAP < 60 mmHg
Incidence of a mean arterial pressure (MAP) \< 60 mmHg during anesthesia for 1 minute or more.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Incidence of a MAP < 60 mmHg | 13779 Participants |
| Hypotension Decision Support | Incidence of a MAP < 60 mmHg | 3798 Participants |
Secondary
Incidence of a MAP < 60 mmHg for > 10 Minutes
Incidence of a mean arterial pressure (MAP) \< 60 mmHg for a cumulative duration of all hypotensive episodes of more than 10 minutes during the anesthetic phase of the procedure.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Incidence of a MAP < 60 mmHg for > 10 Minutes | 6989 Participants |
| Hypotension Decision Support | Incidence of a MAP < 60 mmHg for > 10 Minutes | 1723 Participants |
Secondary
Incidence of a MAP < 60 mmHg for > 20 Minutes
Incidence of a mean arterial pressure (MAP) \< 60 mmHg for a cumulative duration of all hypotensive episodes of more than 20 minutes during the anesthetic phase of the procedure.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Incidence of a MAP < 60 mmHg for > 20 Minutes | 3632 Participants |
| Hypotension Decision Support | Incidence of a MAP < 60 mmHg for > 20 Minutes | 792 Participants |
Secondary
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg
Average concentrations of inhalational anesthesia during MAP \< 50 mmHg episodes
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 50 mmHg and a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg | Sevoflurane (EndTidal %) | 1.32 EndTidal% (other) |
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg | Isoflurane (EndTidal %) | 0.65 EndTidal% (other) |
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg | Desflurane (EndTidal %) | 4.28 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg | Sevoflurane (EndTidal %) | 1.23 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg | Isoflurane (EndTidal %) | 0.65 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg | Desflurane (EndTidal %) | 4.70 EndTidal% (other) |
Secondary
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg
Average concentrations of inhalational anesthesia during MAP \< 55 mmHg episodes
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 55 mmHg and either a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg | Sevoflurane (EndTidal %) | 1.34 EndTidal% (other) |
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg | Isoflurane (EndTidal %) | 0.68 EndTidal% (other) |
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg | Desflurane (EndTidal %) | 4.60 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg | Sevoflurane (EndTidal %) | 1.25 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg | Isoflurane (EndTidal %) | 0.67 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg | Desflurane (EndTidal %) | 4.65 EndTidal% (other) |
Secondary
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg
Average concentrations of inhalational anesthesia during MAP \< 60 mmHg episodes
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 60 mmHg and either a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg | Sevoflurane (EndTidal %) | 1.35 EndTidal% (other) |
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg | Isoflurane (EndTidal %) | 0.68 EndTidal% (other) |
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg | Desflurane (EndTidal %) | 4.36 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg | Sevoflurane (EndTidal %) | 1.25 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg | Isoflurane (EndTidal %) | 0.67 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg | Desflurane (EndTidal %) | 2.33 EndTidal% (other) |
Secondary
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg
Average concentrations of inhalational anesthesia during MAP \< 65 mmHg episodes
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 65 mmHg and a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg | Sevoflurane (EndTidal %) | 1.35 EndTidal% (other) |
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg | Isoflurane (EndTidal %) | 0.68 EndTidal% (other) |
| Usual Care Group | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg | Desflurane (EndTidal %) | 4.10 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg | Sevoflurane (EndTidal %) | 1.27 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg | Isoflurane (EndTidal %) | 0.68 EndTidal% (other) |
| Hypotension Decision Support | Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg | Desflurane (EndTidal %) | 2.31 EndTidal% (other) |
Secondary
In-hospital Mortality
Hospital mortality rate during a single hospital admission after the surgery
Time frame: All postoperative days during a single hospital admission, expected median of 5 days
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | In-hospital Mortality | 487 Participants |
| Hypotension Decision Support | In-hospital Mortality | 137 Participants |
Secondary
Intraoperative Administration of Intravenous Fluids
Total amount (mL) of intravenous fluids (as defined under interventions) administered during the surgical procedure.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Intraoperative Administration of Intravenous Fluids | 1500.00 mL |
| Hypotension Decision Support | Intraoperative Administration of Intravenous Fluids | 1400.00 mL |
Secondary
Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg
Average concentrations of propofol infusion rates during MAP \< 50 mmHg episodes
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 50 mmHg and a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg | 65.00 mcg/kg/min (propofol) |
| Hypotension Decision Support | Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg | 50.00 mcg/kg/min (propofol) |
Secondary
Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg
Average concentrations of propofol infusion rates during MAP \< 55 mmHg episodes
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 55 mmHg and either a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg | 63.95 mcg/kg/min (propofol) |
| Hypotension Decision Support | Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg | 50.00 mcg/kg/min (propofol) |
Secondary
Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg
Average concentrations of propofol infusion rates during MAP \< 60 mmHg episodes
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 60 mmHg and either a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg | 61.07 mcg/kg/min (propofol) |
| Hypotension Decision Support | Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg | 50.00 mcg/kg/min (propofol) |
Secondary
Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg
Average concentrations of propofol infusion rates during MAP \< 65 mmHg episodes
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 65 mmHg and a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg | 60.10 mcg/kg/min (propofol) |
| Hypotension Decision Support | Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg | 48.59 mcg/kg/min (propofol) |
Secondary
Postoperative Acute Kidney Injury Stage 2
Postoperative Acute Kidney Injury (AKI), Stage II or higher according to the KDIGO criteria (Kidney Disease: Improving Global Outcomes). The staging will be based on serum creatinine values, as documentation of urine output is probably not sufficiently accurate. The creatinine measurements are part of routine clinical care. Therefore, absence of creatinine postoperative measurements are considered to be 'no suspicion of kidney injury'. KDIGO defines AKI as any of the following: Increase in serum creatinine by 0.3mg/dL or more within 48 hours or Increase in serum creatinine to 1.5 times baseline or more within the last 7 days or Urine output less than 0.5 mL/kg/h for 6 hours. Stage 1 is 1.5-9x baseline or \>0.3 increase; Stage 2 is 2-2.9x baseline; Stage 3 is 3x baseline, or increase to \> 4, or initiation of renal replacement therapy.
Time frame: Within 7 days after surgery
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Usual Care Group | Postoperative Acute Kidney Injury Stage 2 | AKI stage II or greater | 1 Participants |
| Usual Care Group | Postoperative Acute Kidney Injury Stage 2 | No stage II or greater - Confirmed by measurement | 11002 Participants |
| Usual Care Group | Postoperative Acute Kidney Injury Stage 2 | No postoperative creatinine measurement | 4621 Participants |
| Hypotension Decision Support | Postoperative Acute Kidney Injury Stage 2 | AKI stage II or greater | 0 Participants |
| Hypotension Decision Support | Postoperative Acute Kidney Injury Stage 2 | No stage II or greater - Confirmed by measurement | 3157 Participants |
| Hypotension Decision Support | Postoperative Acute Kidney Injury Stage 2 | No postoperative creatinine measurement | 1171 Participants |
Secondary
Postoperative Rise in Creatinine Levels
Absolute values for serum creatinine before and after surgery will be compared. When multiple postoperative creatinine measurements are made, the maximum difference is reported.
Time frame: Within 7 days after surgery
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). Patients with no routine postoperative creatinine measurements are excluded from the analysis.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Postoperative Rise in Creatinine Levels | 0.00 mg/dL |
| Hypotension Decision Support | Postoperative Rise in Creatinine Levels | 0.00 mg/dL |
Secondary
Time to Discharge Readiness at the Postanesthesia Care Unit (PACU)
The time from arriving at the postanesthesia care unit (PACU) until the time the patient is considered ready for discharge (in minutes).
Time frame: A specific time frame on the day of surgery: from the start of admission to the PACU to discharge from the PACU, an expected average of 4 hours
Population: Only patients with a postoperative stay at the postanesthesia care unit (PACU). Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Time to Discharge Readiness at the Postanesthesia Care Unit (PACU) | 67 minutes |
| Hypotension Decision Support | Time to Discharge Readiness at the Postanesthesia Care Unit (PACU) | 60 minutes |
Secondary
Timing of Cardiovascular Drugs for MAP < 50 mmHg
Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 50 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 50 mmHg and an administration event of a cardiovascular drugs within 5 minutes before the start of the hypotensive episode (the first value below 50 mmHg) and 15 minutes after the start of the episode.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Timing of Cardiovascular Drugs for MAP < 50 mmHg | 1 minutes |
| Hypotension Decision Support | Timing of Cardiovascular Drugs for MAP < 50 mmHg | 0 minutes |
Secondary
Timing of Cardiovascular Drugs for MAP < 55 mmHg
Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 55 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 55 mmHg and an administration event of a cardiovascular drugs within 5 minutes before the start of the hypotensive episode (the first value below 55 mmHg) and 15 minutes after the start of the episode.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Timing of Cardiovascular Drugs for MAP < 55 mmHg | 1 minutes |
| Hypotension Decision Support | Timing of Cardiovascular Drugs for MAP < 55 mmHg | 0.5 minutes |
Secondary
Timing of Cardiovascular Drugs for MAP < 60 mmHg
Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 60 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 60 mmHg and an administration event of a cardiovascular drugs within 5 minutes before the start of the hypotensive episode (the first value below 60 mmHg) and 15 minutes after the start of the episode.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Timing of Cardiovascular Drugs for MAP < 60 mmHg | 0.8 minutes |
| Hypotension Decision Support | Timing of Cardiovascular Drugs for MAP < 60 mmHg | 1.5 minutes |
Secondary
Timing of Cardiovascular Drugs for MAP < 65 mmHg
Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 60 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: All patients with any MAP \< 65 mmHg and an administration event of a cardiovascular drugs within 5 minutes before the start of the hypotensive episode (the first value below 65 mmHg) and 15 minutes after the start of the episode.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Usual Care Group | Timing of Cardiovascular Drugs for MAP < 65 mmHg | 2 minutes |
| Hypotension Decision Support | Timing of Cardiovascular Drugs for MAP < 65 mmHg | 1.14 minutes |
Post Hoc
Postoperative Acute Kidney Injury
Postoperative Acute Kidney Injury (AKI), Stage I or higher according to the KDIGO criteria (Kidney Disease: Improving Global Outcomes). The staging will be based on serum creatinine values, as documentation of urine output is probably not sufficiently accurate. This will be the primary outcome for the Vanderbilt University Medical Center. The creatinine measurements are part of routine clinical care. Therefore, absence of creatinine postoperative measurements are considered to be 'no suspicion of kidney injury'. KDIGO defines AKI as any of the following: Increase in serum creatinine by 0.3mg/dL or more within 48 hours or Increase in serum creatinine to 1.5 times baseline or more within the last 7 days or Urine output less than 0.5 mL/kg/h for 6 hours. Stage 1 is 1.5-9x baseline or \>0.3 increase; Stage 2 is 2-2.9x baseline; Stage 3 is 3x baseline, or increase to \> 4, or initiation of renal replacement therapy.
Time frame: Within 7 days after surgery
Population: Post-Hoc analysis: all patients, not only those with any MAP \< 65 mmHg.
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Usual Care Group | Postoperative Acute Kidney Injury | AKI stage I or greater | 1477 Participants |
| Usual Care Group | Postoperative Acute Kidney Injury | No AKI - Confirmed by measurement | 10690 Participants |
| Usual Care Group | Postoperative Acute Kidney Injury | No postoperative creatinine measurement | 5296 Participants |
| Hypotension Decision Support | Postoperative Acute Kidney Injury | AKI stage I or greater | 435 Participants |
| Hypotension Decision Support | Postoperative Acute Kidney Injury | No AKI - Confirmed by measurement | 3166 Participants |
| Hypotension Decision Support | Postoperative Acute Kidney Injury | No postoperative creatinine measurement | 1371 Participants |
Post Hoc
Usage Frequency of Cardiovascular Drugs: Ephedrine
Cardiovascular drugs as defined under interventions. Frequency of patients receiving the drug. Cardiovascular drugs that were given in \<1% of cases are not reported.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Usage Frequency of Cardiovascular Drugs: Ephedrine | 9310 Participants |
| Hypotension Decision Support | Usage Frequency of Cardiovascular Drugs: Ephedrine | 2718 Participants |
Post Hoc
Usage Frequency of Cardiovascular Drugs: Ephinephrine
Cardiovascular drugs as defined under interventions. Frequency of patients receiving the drug. Cardiovascular drugs that were given in \<1% of cases are not reported.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Usage Frequency of Cardiovascular Drugs: Ephinephrine | 1215 Participants |
| Hypotension Decision Support | Usage Frequency of Cardiovascular Drugs: Ephinephrine | 409 Participants |
Post Hoc
Usage Frequency of Cardiovascular Drugs: Glycopyrrolate
Cardiovascular drugs as defined under interventions. Frequency of patients receiving the drug. Cardiovascular drugs that were given in \<1% of cases are not reported.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Usage Frequency of Cardiovascular Drugs: Glycopyrrolate | 11093 Participants |
| Hypotension Decision Support | Usage Frequency of Cardiovascular Drugs: Glycopyrrolate | 1257 Participants |
Post Hoc
Usage Frequency of Cardiovascular Drugs: Norepinephrine
Cardiovascular drugs as defined under interventions. Frequency of patients receiving the drug. Cardiovascular drugs that were given in \<1% of cases are not reported.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Usage Frequency of Cardiovascular Drugs: Norepinephrine | 762 Participants |
| Hypotension Decision Support | Usage Frequency of Cardiovascular Drugs: Norepinephrine | 233 Participants |
Post Hoc
Usage Frequency of Cardiovascular Drugs: Phenylephrine
Cardiovascular drugs as defined under interventions. Frequency of patients receiving the drug. Cardiovascular drugs that were given in \<1% of cases are not reported.
Time frame: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours
Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Usual Care Group | Usage Frequency of Cardiovascular Drugs: Phenylephrine | 12211 Participants |
| Hypotension Decision Support | Usage Frequency of Cardiovascular Drugs: Phenylephrine | 3685 Participants |