Atelectasis, Postoperative
Conditions
Keywords
cardiopulmonary bypass, lung recruitment maneuver, atelectasis, cardiac surgery, cardiac index, hemodynamics, lung ultrasound, positive end-expiratory pressure
Brief summary
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.
Detailed description
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.
Interventions
PROCEDURESingle Step Lung Recruitment Maneuver
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.
PROCEDUREStepwise Lung Recruitment Maneuver
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.
Sponsors
Ondokuz Mayıs University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Masking description
Both the patients and the clinicians involved in perioperative management are blinded to group allocation. Outcome assessment and data analysis are performed by an investigator who is also blinded to group assignment.
Intervention model description
Participants will be randomized in a 1:1 ratio to receive either a single-step sustained inflation lung recruitment maneuver or a stepwise incremental lung recruitment maneuver after separation from cardiopulmonary bypass.
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Cardiac Index | Intraoperative period | Difference in cardiac index measured before and after the lung recruitment maneuver. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The heart rate measurement | Intraoperative period and postoperative day 1. | 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. |
| The mean arterial pressure measurement | Intraoperative period and postoperative day 1. | Mean arterial pressure 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. |
| Systemic vascular resistance index measurement | Intraoperative period and postoperative day 1. | Systemic vascular resistance index 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. |
| Stroke volume variation | Intraoperative period and postoperative day 1. | Dynamic hemodynamic parameters, including stroke volume variation (SVV, %), will be recorded as separate variables using invasive arterial waveform analysis. Measurements will be obtained 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. |
| Arterial elastance | Intraoperative period and postoperative day 1. | Dynamic hemodynamic parameters including arterial elastance (Ea, mmHg/mL), will be recorded as separate variables using invasive arterial waveform analysis. Measurements will be obtained 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. |
| Contractility | Intraoperative period and postoperative day 1. | Dynamic hemodynamic parameters, including cardiac contractility indices, will be recorded as separate variables using invasive arterial waveform analysis. Measurements will be obtained 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. |
| Lung ultrasound atelectasis score | Intraoperative period and postoperative day 1 | Change in lung ultrasound atelectasis score before and after the recruitment maneuver. Lung aeration was assessed using a 12-region quantitative lung ultrasound (LUS) score (0-36) based on the ESICM-ESPNIC consensus. Each region was graded 0-3 (0 = normal aeration; 1 = mild loss with B-lines/subpleural changes ≤50%; 2 = moderate loss with coalescent B-lines or small consolidation \<2-2.5 cm; 3 = severe loss with large consolidation ≥2-2.5 cm). Higher scores indicated greater aeration loss. |
| Peak airway pressure | Intraoperative period and postoperative day 1. | Peak airway pressure (Ppeak), measured in cmH₂O, will be recorded 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. |
| Plateau pressure | Intraoperative period and postoperative day 1. | plateau pressure (Pplat), measured in cmH₂O, will be recorded 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. |
| Dynamic lung compliance | Intraoperative period and postoperative day 1. | Dynamic lung compliance (Cdyn), expressed as mL/cmH₂O, will be recorded 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. |
| Driving pressure | Intraoperative period and postoperative day 1. | Driving pressure, calculated as plateau pressure minus positive end-expiratory pressure (Pplat - PEEP) and expressed in cmH₂O, will be recorded 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. |
| Positive end-expiratory pressure | Intraoperative period and postoperative day 1. | Positive end-expiratory pressure (PEEP), measured in cmH₂O, will be recorded 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. |
| Arterial pH | Intraoperative period and postoperative day 1. | Arterial pH (unitless) measured by arterial blood gas analysis will be recorded 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. |
| Partial pressure of arterial oxygen | Intraoperative period and postoperative day 1. | Partial pressure of arterial oxygen (PaO₂, mmHg) measured by arterial blood gas analysis will be recorded 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. |
| Partial pressure of arterial carbon dioxide | Intraoperative period and postoperative day 1. | Partial pressure of arterial carbon dioxide (PaCO₂, mmHg) measured by arterial blood gas analysis will be recorded 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. |
| Serum lactate level | Intraoperative period and postoperative day 1 | Change in serum lactate level measured perioperatively. |
| Extubation time | Postoperative day 1 | After the operation, the time until the patient is extubated will be recorded. |
| Length of intensive care unit stay (ICU) | The time from admission to the ICU to the time of discharge to the hospital ward; during the hospital stay, an average of 7 days | Time from ICU admission to ICU discharge. |
Countries
Turkey (Türkiye)
Contacts
CONTACTBurhan Dost, MD
Outcome results
None listed