Oxygen Consumption (V̇O2), Oxygen Delivery (DO2), Post-operative Complications
Conditions
Keywords
non-invasive, measurement of oxygen, consumption, delivery, post-operative complications
Brief summary
The investigators will examine the relationship between post-operative oxygen consumption (using non-invasive measurement technology ) and complications in patients having contemporary major abdominal surgery. The investigators hypothesis is that major surgery may trigger a physiological stress response that results in an increase in post-operative metabolic demand and oxygen consumption (V̇O2) which must be met by an increased oxygen delivery (DO2). 1. To determine the feasibility of non-invasive measurement of oxygen consumption (V̇O2) using indirect calorimetry in a cohort of patients 2. To determine the feasibility of non-invasive measurement of oxygen delivery (DO2) in the same cohort using non-invasive measures of cardiac output, oxygen saturation and haemoglobin (pulse wave transit time and co-oximetry techniques)
Detailed description
Prospective observational study of non-invasive measurements of V̇O2 and DO2 pre-operatively and at 8 time points in the 48 hours postoperatively in a cohort of 40 patients undergoing elective major abdominal surgery (both open and laparoscopic) with a pre-operative cardiopulmonary exercise testing (CPET). As pilot work examining the relationship between post-operative oxygen consumption and complications in patients having contemporary major abdominal surgery , the investigators need to define and grade the severity of complications. The Post-Operative Morbidity Survey (POMS) is a simple outcome scale designed to record the incidence of clinically important complications - specifically complications likely to keep a patient in hospital. A POMS score performed on Day 5 is likely to be discriminative between patients who are recovering well, and those who are developing complications. POMS is easily performed, has good internal validity and is predictive of a prolonged length of stay. POMS is not a simple additive scale; however patients with POMS score of 1 or greater are highly likely to remain in hospital, whereas those with a score of 0 are likely to be able to go home.
Interventions
None listed
Sponsors
University Hospital Plymouth NHS Trust
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Male and female patients aged 18 or over. * Undergoing elective major open or laparoscopic abdominal surgery.
Exclusion criteria
* Refusal to participate * Requirement for post-operative ventilation * Requirement of inspired oxygen concentrations (FiO2) \> 28% to maintain oxygen saturations ≥ 90%.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| postoperative morbidity score (POMS) | Day 5 post surgery | The Post-Operative Morbidity Survey (POMS) is a simple outcome scale designed to record the incidence of clinically important complications - specifically complications likely to keep a patient in hospital. A POMS score performed on Day 5 is likely to be discriminative between patients who are recovering well, and those who are developing complications. POMS is easily performed, has good internal validity and is predictive of a prolonged length of stay. POMS is not a simple additive scale; however patients with POMS score of 1 or greater are highly likely to remain in hospital, whereas those with a score of 0 are likely to be able to go home. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Length of hospital stay | estimated average length of hospital stay of 5 - 7 days | The number of days the patient is in hospital following surgery |
| Unplanned admission to critical care. | Participants will be followed for the duration of hospital stay, an expected average of 5 - 7 days | We are looking at admission to critical care that was not arranged pre-operatively - a certain proportion of patients are routinely admitted to critical care because of medical co-morbidities. We are looking for those patients who were deemed fit enough not to need critical care post-operatively who subsequently need admission there, and the length of their stay there. |
| Returns to the operating theatre | Number of events during Hospital admission (estimated average length of hospital stay of 5 - 7 days) | The number of times a patient has to be returned to the operating theatre during their index admission. |
| Hospital readmission | Within 30 days of discharge from hospital | Number of readmissions to hospital following discharge elated to the patients surgery |
| Mortality | Up to 30 days following hospital discharge | Patient mortality rate following surgery up to 30 days following discharge |
Countries
United Kingdom
Outcome results
None listed