The Cost in Oxygen of Surgical Trauma

The Cost in Oxygen of Surgical Trauma (CO2ST) - a Feasibility Study of the Non-invasive Measurement of Oxygen Delivery and Consumption After Major Abdominal Surgery

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)

Study Overview

• Status: Completed
• Conditions: Post-operative Complications; Oxygen Consumption (V̇O2); Oxygen Delivery (DO2)

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.

• Study Type: Observational
• Enrollment (Anticipated): 40

Contacts and Locations

Study Locations

• United Kingdom
  • Devon
    • Plymouth, Devon, United Kingdom, PL6 8DH
      • Plymouth Hospitals NHS Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients undergoing elective major open or laparoscopic abdominal surgery at Plymouth Hospitals NHS Trust (PHNT)

Description

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%.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Elective major abdominal surgery; Patients undergoing elective major open or laparoscopic abdominal surgery at Plymouth Hospitals National Health Service (NHS) Trust (PHNT)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
postoperative morbidity score (POMS)	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.	Day 5 post surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Length of hospital stay	The number of days the patient is in hospital following surgery	estimated average length of hospital stay of 5 - 7 days
Unplanned admission to critical care.	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.	Participants will be followed for the duration of hospital stay, an expected average of 5 - 7 days
Returns to the operating theatre	The number of times a patient has to be returned to the operating theatre during their index admission.	Number of events during Hospital admission (estimated average length of hospital stay of 5 - 7 days)
Hospital readmission	Number of readmissions to hospital following discharge elated to the patients surgery	Within 30 days of discharge from hospital
Mortality	Patient mortality rate following surgery up to 30 days following discharge	Up to 30 days following hospital discharge

Collaborators and Investigators

• Sponsor: University Hospital Plymouth NHS Trust
• Investigators: Principal Investigator: Adam Kimble, BSc(Hons), MSc, MBBS, MRCS, University Hospital Plymouth NHS Trust

Study record dates

Study Major Dates

• Study Start: November 1, 2014
• Primary Completion (Actual): August 1, 2015
• Study Completion (Actual): August 1, 2015

Study Registration Dates

• First Submitted: September 9, 2014
• First Submitted That Met QC Criteria: September 11, 2014
• First Posted (Estimate): September 12, 2014

Study Record Updates

• Last Update Posted (Estimate): October 30, 2015
• Last Update Submitted That Met QC Criteria: October 29, 2015
• Last Verified: February 1, 2015

More Information

Terms related to this study

• Keywords: non-invasive; delivery; consumption; post-operative complications; measurement of oxygen
• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications
• Other Study ID Numbers: 14/P/123