Influence of Tidal Volume on Postoperative Pulmonary Function

Study Overview
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Brief Summary
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Lung function impairment is common after abdominal surgery. Few preventive strategies exist against postoperative lung function impairment. A new potential preventive strategy against postoperative lung function impairment comes from research on critically ill patients with severe respiratory failure. In this field research has long focused on influence of breathing volume (= tidal volume) during mechanical ventilation on outcome. It has been shown, that low tidal volumes improve patients outcomes as compared to (conventional) high tidal volumes. Therefore, we propose a patient and investigator blinded randomised trial to test the hypotheses that intraoperative mechanical ventilation with low tidal volumes as compared to high tidal volumes reduces postoperative lung function impairment in high risk patients.

Official Title
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Influence of Tidal Volume on Postoperative Pulmonary Function

Conditions
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Pulmonary Function

Intervention / Treatment
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* Other: Randomized application of intraoperative tidal volume
* Other: Randomized application of intraoperative tidal volume


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: written informed consent age ≥ 50 years and ASA classification ≥ II elective upper abdominal surgery of at least 3 hours duration general anaesthesia plus epidural anaesthesia. Exclusion Criteria: < 18 years of age impaired mental state unwillingness to participate pregnancy duration of surgery < 3 hours ASA physical status ≥ IV increased intracranial pressure neuromuscular disease that impairs spontaneous breathing

Ages Eligible for Study
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Minimum Age: 50 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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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>intraoperative mechanical ventilation with 6 ml/kg predicted body weight | Other: Randomized application of intraoperative tidal volume<br>* intraoperative mechanical ventilation with 6 ml/kg predicted body weight<br>* Other names: Respiratory management;|
| Active Comparator: 2<br>intraoperative mechanical ventilation with 12 ml/kg predicted body weight | Other: Randomized application of intraoperative tidal volume<br>* intraoperative mechanical ventilation with 12 ml/kg predicted body weight<br>* Other names: Respiratory management;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lung function as assessed by spirometry |  | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| lung function as assessed by blood gas analysis |  | 1 year | 
| time till hospital discharge |  | 1 year | 
| postoperative organ dysfunction |  | 1 year | 
| postoperative chest x-rays |  | 1 year | 
| time till mobilisation |  | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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tidal volume, predicted body weight, lung function, respiratory outcome, Respiratory Function Tests, surgery