Anaesthetic Management Guided by COMET Measurements

Study Overview
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Brief Summary
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Surgical site infection (SSI) is a significant cause of morbidity and mortality, prolonged hospital stays and healthcare costs. Perioperative low tissue oxygen tension is associated with a high risk of SSI. Standard anaesthetic management guided by continuous monitoring of oxygen delivery with a non-invasive method of measuring mitochondrial oxygenation tension (mitoPO2) using the Cellular Oxygen METabolism (COMET) monitor may benefit the intraoperative oxygenation on the tissue level. This randomised, controlled, single-centre, parallel-arm, patient-blinded trial aims to investigate if standard anaesthetic management guided by mitoPO2 monitoring results in higher tissue oxygen tension including patients undergoing elective abdominal surgery. Anaesthetists in the intervention group strive to a minimum mitoPO2 of 66 mmHg. Patients in the control group receive standard care. The primary outcome is the difference in means of the mean mitoPO2 during surgery.

Official Title
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Anaesthetic Management Guided by Cellular Oxygen Metabolism Measurements in Abdominal Surgery: a Randomised Controlled Trial

Conditions
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Mitochondrial Oxygenation Measurement, Surgical Site Infection

Intervention / Treatment
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* Other: COMET monitoring device


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients are at least 18 years old Patients undergo elective open or laparoscopic abdominal surgery with an expected minimal total incision size of 5 cm Patients are able and willing to give written informed consent Exclusion Criteria: Known photodermatoses of varying pathology and frequency Mitochondrial disease Porphyria Skin lesions on the upper arm which impede measurements Hypersensitivity to the active substance or the 5-ALA medicated plaster material Emergency surgery Reoperation for complications from recent surgery (within last three months) Participation in another study with interference with this study Pregnancy or breastfeeding

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: A randomised, controlled, single-centre, parallel-arm, patient-blinded trial
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: COMET monitoring device<br>Anaesthetists for patients allocated to the intervention group were asked to strive and maintain the intraoperative mitoPO2 to the individualised preoperative baseline mitoPO2 with a minimum of 66 mmHg | Other: COMET monitoring device<br>* Cellular Oxygen METabolism (COMET) mitochondrial oxygen tension monitoring device<br>|
| No Intervention: Control group<br>Patients allocated to the control group were treated as per anaesthetist preference and followed our institution's conventional care | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean mitoPO2 during abdominal surgery over time | Absolute difference between the means of the mean mitoPO2 | during surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Surgical site infection | Surgical site infection rate according to the CDC definition [1]. | 30 days follow-up | 
| MitoPO2 above baseline | The percentage of surgery time that the intraoperative mitoPO2 is above baseline | during surgery | 
| Exploration analysis of the correlation coefficients between the intraoperative mitoPO2 and the intraoperative monitoring measurement values | Calculation of the correlation coefficients between the intraoperative mitoPO2 values and the intraoperative values of each monitoring measurement. The measurement pairs are defined as measurements performed within the same time interval. The mean value is used if multiple measurements of the same type have been performed in that time interval. The outcomes are the pooled correlation coefficients of the correlation between the mitoPO2 and each monitoring measure. We going to examine the following monitoring measurements: non-invasive or arterial blood pressure in mmHg, plethysmographic variability index, heart rate, peripheral oxygen saturation, temperature in Celsius, end-tidal oxygen in mmHg, end-tidal carbon dioxide in mmHg and amplitude frequency effect (pulse pressure and heart rate)). | during intraoperative anaesthetic procedure | 
| The respective effect per intervention in mitoPO2 after notification in which mitoPO2 aids decision making on anaesthetic management | The potential effects of the anaesthetic interventions on the mitoPO2 values is assessed amongst patients from the intervention group. The anaesthetic interventions of interest are only those given to increase the mitoPO2 values. For all these interventions, we look for the difference between aggregated mitoPO2 values over a period before administering the anaesthetic intervention and aggregated mitoPO2 values over a period when the treatment is active. The lengths of the intervals, the time between intervals, and the type of aggregation are based on the observable patterns in the data. The time between intervals is at least the average time for the anaesthetic intervention to reach maximum plasma concentration; this duration may be longer because the effect could be delayed. If possible, we summarise the effect of the anaesthetic interventions by type and dose. | during intraoperative anaesthetic procedure | 
| Effect when using the COMET in sequentially treated patients in mitoPO2 assessed with a mixed effects model | The relationship between the intervention number of patients from the interventions group sequentially treated by one anaesthetist and the mean intraoperative mitoPO2 value. The effect is defined as the average increase in mean intraoperative mitoPO2 when an anaesthetist treats a new patient from the intervention group. | during surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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mitochondria, mitochondrial oxygenation, tissue oxygenation, microcirculation, surgical site infection, wound infection, abdominal surgery