The Incidence of Postoperative Pulmonary Complications in Patients With a Positive and Negative AIR-Test During General Anesthesia

Study Overview
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Brief Summary
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The overall objective of this study is to describe the incidence of postoperative pulmonary complications in patients with a positive and negative AIR-test result. Second, the investigators wish to describe the incidence of a positive AIR-test and its association with the development of PPC. In addition, the investigators aim to describe whether mechanical ventilation strategy differs between patients with a positive and negative AIR-test.

Detailed Description
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The 'AIR-test', a method wherein inspiratory oxygen concentration is reduced to 21% and pulse-oximetry hemoglobin saturation (SpO2) is monitored, can be used to demonstrate the presence of an atelectasis-induced alveolar shunt. It remains uncertain whether an intraoperative positive AIR-test is associated with clinical outcomes. It is hypothesized that in a general surgical population, the incidence of postoperative pulmonary complications (PPC) is higher in patients with a positive AIR-test than in patients with a negative AIR-test. The aim of this study is to describe the incidence of PPC in patients with a positive and in patients with a negative AIR-test. Second, the investigators want to describe the incidence of a positive AIR-test and its association with the development of PPC. The investigators also want to evaluate whether mechanical ventilation strategy differs between patients with a positive and negative AIR-test.

Official Title
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The Incidence of Postoperative Pulmonary Complications in Patients With a Positive and Negative AIR-Test During General Anesthesia

Conditions
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Surgery--Complications, Atelectasis, Anesthesia

Intervention / Treatment
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* Procedure: Surgery


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing surgery under general anesthesia in the Amsterdam University Medical Centers, location Meibergdreef with an Endotracheal Tube; Patients > 18 years; Preoperative SpO2 of ≥97%; AIR-test performed after induction of anesthesia, in a hemodynamic and respiratory steady state. Exclusion Criteria: Age < 18 years; No consent/objection; Patient participated in another conflicting interventional study on mechanical ventilation during general anesthesia

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 110 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Positive AIR-test<br>Patients with a positive intraoperative AIR-test result | Procedure: Surgery<br>* All types of surgery requiring general anesthesia<br>|
| Negative AIR-test<br>Patients with a negative intraoperative AIR-test result | Procedure: Surgery<br>* All types of surgery requiring general anesthesia<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The incidence of postoperative pulmonary complications | Respiratory failure; Bronchospasm; Acute Respiratory Distress Syndrome (ARDS); Suspected pulmonary infection; Aspiration pneumonitis; Atelectasis; Pleural effusion; Pulmonary infiltrate; Cardiopulmonary effusion; Pneumothorax | The first 5 postoperative days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| AIR-test result | Number of patients with a positive and negative AIR-test | Intraoperative period | 
| Tidal volume during general anesthesia for surgery | Tidal volume in mL per kg predicted bodyweight | Intraoperative period | 
| Positive End-Expiratory Pressure during general anesthesia for surgery | Positive End-Expiratory Pressure in Centimeters of Water (cmH2O) | Intraoperative period | 
| Peak Pressure during general anesthesia for surgery | Peak Pressure in cmH20 | Intraoperative period | 
| Driving Pressure during general anesthesia for surgery | Driving Pressure in cmH2O | Intraoperative period | 
| Fraction of Inspired Oxygen during general anesthesia for surgery | Fraction of Inspired Oxygen | Intraoperative period | 
| End-tidal Carbon Dioxide (CO2) during general anesthesia for surgery | End-tidal CO2 in millimeters of mercury (mmHg) | Intraoperative period | 
| Respiratory Rate during general anesthesia for surgery | Respiratory Rate per minute | Intraoperative period | 
| The incidence of the individual components of postoperative pulmonary complications | Respiratory failure; Bronchospasm; ARDS; Suspected pulmonary infection; Aspiration pneumonitis; Atelectasis; Pleural effusion; Pulmonary infiltrate; Cardiopulmonary effusion; Pneumothorax | The first 5 postoperative days | 
| Length of hospital stay | Days of hospital stay | From the day of surgery until the day of discharge, up to day 30 | 
| Rate of all-cause mortality and in-hospital mortality | Mortality rate | Postoperative day 5 and postoperative day 30 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Anesthesia, AIR-test, Postoperative Pulmonary Complications