Single-step vs Stepwise Lung Recruitment Maneuvers After Cardiopulmonary Bypass

Ondokuz Mayıs University52 enrolled

Overview

This prospective randomized controlled trial aims to compare the hemodynamic and pulmonary effects of single-step and stepwise lung recruitment maneuvers in adult patients undergoing elective cardiac surgery with cardiopulmonary bypass. After separation from cardiopulmonary bypass, patients will be randomized to receive either a single-step sustained inflation recruitment maneuver or a stepwise incremental recruitment maneuver, both combined with 8 cmH₂O positive end-expiratory pressure. The primary outcome is the change in cardiac index before and after the recruitment maneuver. Secondary outcomes include lung ultrasound atelectasis score, and hemodynamic parameters.

Atelectasis frequently develops after cardiopulmonary bypass due to lung ischemia-reperfusion injury, inflammatory response, and mechanical factors related to cardiac surgery. Lung recruitment maneuvers are commonly used to improve lung aeration and oxygenation; however, increased intrathoracic pressure during recruitment may negatively affect venous return and cardiac output. In this randomized controlled trial, adult patients undergoing elective open-heart surgery with cardiopulmonary bypass will be allocated to receive either a single-step sustained inflation recruitment maneuver or a stepwise incremental recruitment maneuver, both combined with 8 cmH₂O positive end-expiratory pressure after separation from cardiopulmonary bypass. Hemodynamic variables, particularly cardiac index, will be assessed before and after recruitment. Pulmonary effects will be evaluated using lung ultrasound atelectasis scoring and arterial blood gas analysis. The study aims to identify the recruitment strategy that provides optimal pulmonary benefits while preserving hemodynamic stability in this high-risk patient population.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Enrollment

Interventions

Single Step Lung Recruitment ManeuverPROCEDURE

A sustained inflation lung recruitment maneuver with an airway pressure of 30 cmH₂O applied for 30 seconds after separation from cardiopulmonary bypass, combined with 8 cmH₂O positive end-expiratory pressure.

Stepwise Lung Recruitment ManeuverPROCEDURE

A stepwise lung recruitment maneuver in which airway pressure is increased by 5 cmH₂O every 5 seconds up to 30 cmH₂O and then decreased in the same manner after separation from cardiopulmonary bypass, combined with 8 cmH₂O positive end-expiratory pressure.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 80 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age 18-80 years * ASA (American Society of Anesthesiologists) II-IV * Patients undergoing elective cardiac surgery (coronary artery bypass grafting, mitral valve replacement, aortic valve replacement) Exclusion Criteria: * Emergency surgery * Presence of perioperative arrhythmia * \<35% left ventricular ejection fraction * \>50 mmHg systolic pulmonary artery pressure * Known chronic obstructive pulmonary disease or interstitial lung disease * Pneumothorax * Mean arterial pressure \<60 mmHg during recruitment maneuver * New York Heart Association (NYHA) class III-IV heart failure * Advanced cardiomyopathy or severe mitral regurgitation * Cross-clamp time longer than 2 hours * Requirement for high-dose inotropic or vasopressor support * Patients who cannot be extubated after postoperative 24 hours

Outcomes

Primary Outcomes

Change in Cardiac Index

Difference in cardiac index measured before and after the lung recruitment maneuver.

Time frame: Intraoperative period

Secondary Outcomes

The heart rate measurement

Heart rate will be recorded preoperatively; after induction; immediately before the recruitment maneuver (RM); during RM at the point of maximum airway pressure; at the end of RM; 30 minutes after RM; at postoperative hour 1; and immediately after extubation.