Rest PETCO2 as a Predictor of Post-operative Complications

Study Overview
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Brief Summary
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Cardiopulmonary exercise testing (CPET) is considered to be a golden standard in preoperative risk assessment and stratification of high risk patients scheduled for major surgery. However, not all of the patients requiring surgery are willing or able to complete this type of testing. Vascular surgery patients are predominantly elderly people, with significant comorbidity and high degree of frailty and often can not undergo CPET. In recent years, new parameters with similar prognostic value as standard CPET parameters were studied. Specifically, the partial pressure of end-tidal carbon dioxide (PETCO2) at rest has been shown to have the same prognostic value as ventilatory efficiency. We hypothesized low PETCO2 at rest will be associated with the development of pulmonary and cardiovascular post-operative complications in patients after major vascular surgery. Accordingly, our aim is to compare PETCO2 measured at rest before surgery in patients who develop post-operative complications and in those who do not.

Detailed Description
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Cardiopulmonary exercise testing (CPET) is considered to be a golden standard in preoperative risk assessment and stratification of high risk patients scheduled for major surgery. However, not all of the patients requiring surgery are willing or able to complete this type of testing. Moreover, inability to perform CPET has been linked with inferior outcomes following surgery. Vascular surgery patients are predominantly elderly people, with significant comorbidity and high degree of frailty. Therefore, CPET as a mean of risk stratification would be of an especial interest in this group of patients. However, vascular surgery patients often present with peripheral arterial disease, which may contribute to early leg ischemia during exercise and therefore invalid cardiorespiratory reserve function measurement. In recent years, new parameters with similar prognostic value as standard CPET parameters were studied. Specifically, the partial pressure of end-tidal carbon dioxide (PETCO2) at rest has been shown to have the same prognostic value as ventilatory efficiency in the prediction of post-operative complications in lung resection surgery patients. Whether the same parameter can be used to predict postoperative complications in a different sub-set of surgical patients (i.e. vascular surgery patients) is yet to be determined. We hypothesized low PETCO2 at rest will be associated with the development of pulmonary and cardiovascular post-operative complications in patients after major vascular surgery. Accordingly, our aim is to compare PETCO2 measured at rest before surgery in patients who develop post-operative complications and in those who do not.

Official Title
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Rest PETCO2 as a Predictor of Post-operative Complications in Patient Undergoing Major Vascular Surgery

Conditions
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Post-Op Complication

Intervention / Treatment
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* Diagnostic Test: end-tidal CO2 measurement


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: indication for major vascular surgery (aortobifemoral bypass surgery) Exclusion Criteria: tracheostomy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| vascular surgery candidates<br>End-tidal CO2 will be measured day before surgery. Post-operative cardiovascular and pulmonary complications will be monitored fron the hospital stay, or first 30 days. | Diagnostic Test: end-tidal CO2 measurement<br>* Measurements will take place day before surgery, under resting conditions (while sitting in a quiet room with no disruptions) using the Capnography monitor from Nonin Medical (breath by breath data will be recorded and analyzed). Patients will be allowed to get used to the nasal cannula for the first two minutes. Mean end-tidal CO2 value will then be calculated from the following two minutes of spontaneous breathing.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| pulmonary complications | post-operative complications | first 30-post operative days | 
| post-operative complications | cardiovascular complications | first 30-post operative days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| hospital length of stay | hospital length of stay | up to 30 days | 
| intensive care unit length of stay | intensive care unit length of stay | up to 30 days | 
| mortality | mortality | from the first 30-post operative days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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vascular surgery, cardiopulmonary exercise testing, end-tidal CO2