Effect of PEEP on Cardiac Function

Официальное название

The Effect of Positive End-Expiratory Pressure on Biventricular Mechanics in the Perioperative Setting

Обзор

The purpose of this single-center, prospective study is to evaluate the physiologic effect of changes in PEEP on biventricular mechanics and RV-pulmonary arterial (RV-PA) coupling in adult patients undergoing cardiac surgery.

Подробное описание

Positive end-expiratory pressure (PEEP) is a critical modality of mechanical ventilation but has important and often underappreciated effects on biventricular mechanics. PEEP is frequently selected based primarily on respiratory mechanics and oxygenation targets; however, increasing intrathoracic pressure may reduce RV preload by elevating right atrial pressure, while increasing transpulmonary pressure may increase RV afterload by compressing intra-alveolar pulmonary vessels and redistributing pulmonary blood flow. This is important specifically in the context of cardiac surgery where right ventricular (RV) function plays a critical role in determining postoperative morbidity and mortality. Perioperative RV dysfunction has been consistently associated with adverse outcomes, including prolonged vasopressor and inotrope requirements, difficulty weaning from cardiopulmonary bypass, longer intensive care unit stays, and increased mortality.

Right ventricular-pulmonary arterial (RV-PA) coupling provides a physiologically integrated assessment of RV performance by quantifying the relationship between RV contractility and afterload. Animal studies have shown that incremental PEEP increases can impair biventricular mechanics and precipitate RV-PA uncoupling. However, these physiologic effects have not been systematically characterized in the perioperative setting in the cardiac surgery population. This protocol seeks to address this knowledge gap by systematically evaluating biventricular mechanics and RV-PA coupling across varying PEEP levels in a controlled setting, using tools already employed in routine cardiac surgical care (pulmonary artery catheter and intraoperative TEE).

The overarching goal of this proposal is to define how perioperative positive end-expiratory pressure alters biventricular mechanics and right ventricular-pulmonary arterial coupling, to inform physiologically guided, RV-protective ventilatory strategies during cardiac surgery.

Вмешательства

• Процедура EIT Guided PEEP Trial
  Electrical impedance tomography (EIT) will be used to guide identification of "optimal PEEP" based on lung mechanics. After induction of anesthesia and initiation of controlled mechanical ventilation, EIT data will be collected during a brief standardized PEEP titration maneuver to assess lung recruitment and overdistension.

Первичные конечные точки

• Right ventricle-pulmonary artery coupling (Ees/Ea) [Срок оценки: During the standardized PEEP titration sequence after induction of anesthesia and before surgical intervention (approximately 20-25 minutes)]

Вторичные конечные точки (12)

• Right ventricular end-diastolic volume at predefined PEEP levels [Срок оценки: During PEEP titration sequence (approximately 20-25 minutes after induction of anesthesia and prior to surgical incision)]
• Right ventricular end-systolic volume at predefined PEEP levels [Срок оценки: During standardized PEEP titration sequence after induction of anesthesia and prior to surgical incision (approximately 20-25 minutes)]
• Right ventricular stroke volume at predefined PEEP levels [Срок оценки: During standardized PEEP titration sequence after induction of anesthesia and prior to surgical incision (approximately 20-25 minutes)]
• Right ventricular end-diastolic pressure at predefined PEEP levels [Срок оценки: During standardized PEEP titration sequence after induction of anesthesia and prior to surgical incision (approximately 20-25 minutes)]
• Right ventricular end-systolic pressure at predefined PEEP levels [Срок оценки: During standardized PEEP titration sequence after induction of anesthesia and prior to surgical incision (approximately 20-25 minutes)]
• Pulmonary artery systolic pressure at predefined PEEP levels [Срок оценки: During standardized PEEP titration sequence after induction of anesthesia and prior to surgical incision (approximately 20-25 minutes)]
• Mean pulmonary artery pressure at predefined PEEP levels [Срок оценки: During standardized PEEP titration sequence after induction of anesthesia and prior to surgical incision (approximately 20-25 minutes)]
• Right ventricular end-systolic elastance at predefined PEEP levels [Срок оценки: During standardized PEEP titration sequence after induction of anesthesia and prior to surgical incision (approximately 20-25 minutes)]
• Effective arterial elastance at predefined PEEP levels [Срок оценки: During standardized PEEP titration sequence after induction of anesthesia and prior to surgical incision (approximately 20-25 minutes)]
• Three-dimensional right ventricular ejection fraction [Срок оценки: During standardized PEEP titration sequence after induction of anesthesia and prior to surgical incision (approximately 20-25 minutes)]
• Left ventricular ejection fraction at predefined PEEP levels [Срок оценки: During standardized PEEP titration sequence after induction of anesthesia and prior to surgical incision (approximately 20-25 minutes)]
• Left ventricular stroke volume at predefined PEEP levels [Срок оценки: During standardized PEEP titration sequence after induction of anesthesia and prior to surgical incision (approximately 20-25 minutes)]

Критерии участия

Критерии включения

• 1\. Age ≥ 18 years
• 2\. Scheduled to undergo cardiac surgery requiring general anesthesia
• 3\. Planned use of intraoperative transesophageal echocardiography (TEE) as part of routine clinical care
• 4\. Planned placement of a pulmonary artery catheter as part of clinical care (Pulmonary artery catheter placement will be performed solely based on clinical judgment by the treating anesthesia and surgical teams. At our institution, pulmonary artery catheters are routinely placed in cardiac surgery patients with clinical indications including:

• preoperative pulmonary hypertension (e.g., estimated PCWP >20 mmHg or elevated filling pressures on preoperative echocardiography),
• right ventricular dysfunction or suspected RV failure (preoperative visual TTE assessment),
• significant cardiopulmonary comorbidity,
• or anticipated complex, prolonged, or high-acuity cardiac surgery. The research team will not influence decisions regarding catheter placement. Only patients already scheduled to receive a clinically indicated pulmonary artery catheter will be eligible for enrollment.)
• 5\. Able and willing to provide written informed consent prior to surgery

Критерии исключения

• 1\. Significant arrhythmia (e.g., atrial fibrillation with uncontrolled ventricular response or other rhythm disturbances) that would interfere with reliable pressure waveform or echocardiographic measurements.
• 2\. Severe valvular disease where protocol-related PEEP changes may pose unacceptable hemodynamic risk, as determined by the clinical team.
• 3\. Significant chronic lung disease or other pulmonary pathology where PEEP adjustments may be unsafe (e.g., severe COPD with dynamic hyperinflation, bullous lung disease), at the discretion of the anesthesia team.
• 4\. Contraindication to changes in PEEP, including inability to tolerate the planned PEEP titration due to hemodynamic instability or clinician concern.
• 5\. Any contraindication to TEE (if clinically required TEE is not performed or is contraindicated, the subject will not be eligible)
• 6\. Investigator or clinical team discretion (e.g., safety concerns, inability to obtain reliable measurements, or conflict with other perioperative research protocols)

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Нет

Дизайн исследования

Распределение

Не применимо

Модель

Одна группа

Маскирование

Открытое

Основная цель

Фундаментальное исследование

Центры проведения

США · 1 центр

• Beth Israel Deaconess Medical Center — Boston

Публикации

• Bellofiore A, Vanderpool R, Brewis MJ, Peacock AJ, Chesler NC. A novel single-beat approach to assess right ventricular systolic function. J Appl Physiol (1985). 2018 Feb 1;124(2):283-290. doi: 10.1152/japplphysiol.00258.2017. Epub 2017 Oct 12. PMID 29025899
• Araos J, Glocker F, Owyang CG, Teran F, Kim J, Nieman G, Heerdt PM. Biventricular Response to Positive End-expiratory Pressure in Swine: Assessment Based on Beat-to-beat Pressure Waveform Analysis. Anesthesiology. 2025 Apr 1;142(4):767-769. doi: 10.1097/ALN.0000000000005363. Epub 2025 Feb 13. No abstract available. PMID 39946198
• Wood G, Madsen TL, Kim WY, Lyhne MD. Increasing Levels of Positive End-expiratory Pressure Cause Stepwise Biventricular Stroke Work Reduction in a Porcine Model. Anesthesiology. 2024 Feb 1;140(2):240-250. doi: 10.1097/ALN.0000000000004821. PMID 37905995
• Acosta P, Santisbon E, Varon J. "The use of positive end-expiratory pressure in mechanical ventilation". Crit Care Clin. 2007 Apr;23(2):251-61, x. doi: 10.1016/j.ccc.2006.12.012. PMID 17368169
• Ahmed U, Mahmood F, Nicoara A, Kiarad V. Right Ventricular Function and Echocardiographic Pressure-Volume Loops: Overview and Perioperative Clinical Implications. J Cardiothorac Vasc Anesth. 2025 Oct;39(10):2857-2865. doi: 10.1053/j.jvca.2025.05.019. Epub 2025 May 17. PMID 40483247
• Kiarad V, Mahmood F, Hedayat M, Yunus R, Nicoara A, Liu D, Chu L, Senthilnathan V, Kai M, Khabbaz K. Intraoperative right ventricular end-systolic pressure-volume loop analysis in patients undergoing cardiac surgery: A proof-of-concept methodology. JTCVS Open. 2024 Sep 26;22:225-234. doi: 10.1016/j.xjon.2024.09.020. eCollection 2024 Dec. PMID 39780800

Идентификаторы

NCT: NCT07531602 · 2026P000077

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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