Anesthesia, Hypotension, Hypotension on Induction
Conditions
Keywords
Hypotension, Low Blood Pressure, Anesthesia Induction, Surgery
Brief summary
In this clinical proof-of-concept study, the aim is to investigate the efficacy of a hypotension avoidance strategy to prevent post-induction hypotension. Specifically, it will be investigate how much postinduction hypotension occurs when using a hypotension avoidance strategy - combining continuous intraarterial blood pressure monitoring, careful administration of anesthetic drugs, and continuous administration of norepinephrine to treat hypotension - in high-risk patients having elective non-cardiac surgery.
Detailed description
Hypotension is common in patients having non-cardiac surgery with general anesthesia and is associated with organ injury. About one third of hypotension occurs postinduction - i.e., after the induction of general anesthesia but before surgical incision. Unmodifiable risk factors for postinduction hypotension include age, male sex, and a high American Society of Anesthesiologists physical status. However, postinduction hypotension is mainly driven by modifiable factors - specifically, anesthetic drugs that cause vasodilation. Vasodilation can be effectively treated with vasopressors, e.g. norepinephrine. It is reasonable to assume that postinduction hypotension is largely avoidable by careful anesthetic and hemodynamic monitoring and management during anesthetic induction. A hypotension avoidance strategy could include continuous intraarterial blood pressure monitoring, careful administration of anesthetic drugs, and continuous administration of norepinephrine to treat hypotension. However, it remains unknown to which extent a hypotension avoidance strategy actually can avoid postinduction hypotension. Before testing the effectiveness of hypotension avoidance strategies in large-scale randomized trials it is important to investigate their efficacy. In this clinical proof-of-concept study, the aim is to investigate the efficacy of a hypotension avoidance strategy to prevent post-induction hypotension. Specifically, it will be investigate how much postinduction hypotension occurs when using a hypotension avoidance strategy - combining continuous intraarterial blood pressure monitoring, careful administration of anesthetic drugs, and continuous administration of norepinephrine to treat hypotension - in high-risk patients having elective non-cardiac surgery.
Interventions
PROCEDUREMonitoring
Continuous blood pressure monitoring
PROCEDURENorepinephrine preparation
Norepinephrine infusion will be prepared and connected to peripheral or central venous catheter (infusion will not be started)
PROCEDUREPropofol administration
Propofol infusion will be started only when clinical effects of opioid are noticeable: 1.5 mg/kg propofol in patients less than 55 years old and 1.0 mg/kg propofol in patients 55 years or older over 90 seconds
PROCEDUREAlarm adjustment
Lower mean arterial pressure alarm threshold will be set to 75 mmHg
PROCEDUREIntervention threshold
Lower mean arterial pressure intervention threshold will be 75 mmHg: continuous norepinephrine infusion will be started when mean arterial blood decreases below 75 mmHg
Sponsors
Universitätsklinikum Hamburg-Eppendorf
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
This is a prospective, single center, clinical interventional proof-of-concept study in 120 patients scheduled for elective major non-cardiac surgery at the University Medical Center Hamburg-Eppendorf.
Eligibility
Sex/Gender
ALL
Age
45 Years to 130 Years
Healthy volunteers
No
Inclusion criteria
* American Society of Anesthesiologists physical status classification III or higher, and in whom intraarterial blood pressure monitoring is planned for clinical indication
Exclusion criteria
* Emergency surgery * Transplant surgery * History of organ transplant * Sepsis * Pregnancy * Contraindications for the use of propofol * Rapid sequence induction
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Area under a MAP of 65 mmHg | First 15 minutes of induction of general anesthesia | Area under a mean arterial pressure (MAP) of 65 mmHg within the first 15 minutes of anesthetic induction \[mmHg x min\]. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Area under threshold | First 15 minutes of induction of general anesthesia | Area under a MAP of 60, 50, and 40 mmHg \[mmHg x min\] |
| Duration | First 15 minutes of induction of general anesthesia | Duration of MAP \<65, \<60, \<50, and \<40 mmHg \[min\] |
| Any Hypotension | First 15 minutes of induction of general anesthesia | Absolute \[n\] and relative \[%\] number of patients with any MAP measurement \<65, \<60, \<50, and \<40 mmHg |
| 1-minute Hypotension | First 15 minutes of induction of general anesthesia | Absolute \[n\] and relative \[%\] number of patients with at least one 1-minute episode of a MAP \<65, \<60, \<50, and \<40 mmHg |
| Area above the curve | First 15 minutes of induction of general anesthesia | Area above a MAP of 100, 110, 120, 140 mmHg \[mmHg x min\] |
| Norepinephrine | First 15 minutes of induction of general anesthesia | Cumulative dose of norepinephrine indexed to body weight \[μg kg-1\] |
Other
| Measure | Time frame | Description |
|---|---|---|
| Cardiac Output/Index (Exploratory Endpoint) | First 15 minutes of induction of general anesthesia | Descriptive analysis including minimum value, duration under threshold, area under threshold, absolute and relative number of patients with at least one episode under threshold. |
| Stroke Volume/Index (Exploratory Endpoint) | First 15 minutes of induction of general anesthesia | Descriptive analysis including minimum value, duration under threshold, area under threshold, absolute and relative number of patients with at least one episode under threshold. |
| dP/dt (Exploratory Endpoint) | First 15 minutes of induction of general anesthesia | Descriptive analysis including minimum value, duration under threshold, area under threshold, absolute and relative number of patients with at least one episode under threshold. |
| Eadyn (Exploratory Endpoint) | First 15 minutes of induction of general anesthesia | Descriptive analysis including minimum value, duration under threshold, area under threshold, absolute and relative number of patients with at least one episode under threshold. |
| Stroke volume variation (Exploratory Endpoint) | First 15 minutes of induction of general anesthesia | Descriptive analysis including minimum value, duration under threshold, area under threshold, absolute and relative number of patients with at least one episode under threshold. |
| Pulse pressure variation (Exploratory Endpoint) | First 15 minutes of induction of general anesthesia | Descriptive analysis including minimum value, duration under threshold, area under threshold, absolute and relative number of patients with at least one episode under threshold. |
| Systemic vascular resistance (Exploratory Endpoint) | First 15 minutes of induction of general anesthesia | Descriptive analysis including minimum value, duration under threshold, area under threshold, absolute and relative number of patients with at least one episode under threshold. |
Countries
Germany
Outcome results
None listed