Zero Positive End-expiratory Pressure Before Emergence Prevents Postoperative Atelectasis.

Atelectasis Clinical Trial

Official title: Zero Positive End-expiratory Pressure Applied Before Emergence Preoxygenation Prevents Postoperative Atelectasis - a Randomized Controlled Trial.

Status Completed

Clinical Trial Summary

A study on healthy patients undergoing anesthesia for non-abdominal surgery - evaluation of positive end-expiratory pressure versus zero positive end-expiratory pressure on the amount of atelectasis in the early postoperative period.

Clinical Trial Description

Positive end-expiratory pressure (PEEP) is often used during mechanical ventilation to preserve end-expiratory lung volume. After emergence and extubation, this volume will diminish instantly. Some patients will have difficulties to restore functional residual capacity (FRC) during the early phase of recovery. If routine high FIO2 has been delivered together with maintained PEEP prior to extubation, several important prerequisites are established for the development of postoperative atelectasis. The investigators hypothesize that establishing zero positive end-expiratory pressure (ZEEP) immediately prior to emergence preoxygenation, will prevent gas with high oxygen concentration from entering dorso-basal areas of the lungs, and thereby prevent postoperative atelectasis formation.

This randomized controlled study will study patients undergoing non-abdominal day case surgeries under general anesthesia. The patients in the two study groups will receive mechanical ventilation with identical settings, comprising low TV, moderate PEEP, and no RM. At the end of surgery, the lungs will be examined by CT, and any atelectasis areas will be calculated. Randomization will occur after the first CT. The patients will be allocated to zero PEEP (ZEEP) or maintained PEEP during emergence preoxygenation and extubation. Importantly, the intervention group will have ZEEP established while still having low ETO2 levels, prior to any preoxygenation. The study subjects will be examined with CT no.2 approximately thirty min after extubation. Primary endpoint measure will be atelectasis area as a percentage of total lung area. Blood gases will be collected for comparison of oxygenation as a secondary outcome measure. ;

Related Conditions & MeSH terms

• Atelectasis
• Oxygenation
• Pulmonary Atelectasis

• NCT number: NCT03351946
• Study type: Interventional
• Source: Region Västmanland
• Status: Completed
• Phase: N/A
• Start date: December 4, 2017
• Completion date: August 28, 2018