Standardized Lung Recruitment and Positive End-expiratory Pressure Titration in Acute Respiratory Distress Syndrome

Summary

Recruitment maneuvers (RMs) and PEEP titration improve gas exchange and reduce ventilator-induced lung injury in ARDS. This protocol demonstrates clinically applicable recruitment strategies, including sigh, sustained inflation, stepwise PEEP, APRV, and prone positioning, and individualized PEEP maintenance and de-escalation procedures using dynamic monitoring tools.

Abstract

Acute Respiratory Distress Syndrome (ARDS) is characterized by diffuse alveolar injury, refractory hypoxemia, and high mortality. Lung recruitment maneuvers (RMs) aim to reopen collapsed alveoli and improve oxygenation, while positive end-expiratory pressure (PEEP) titration prevents decruitment and maintains alveolar stability. This protocol outlines five clinically feasible RM strategies: sigh, sustained inflation, stepwise PEEP recruitment, APRV-based recruitment, and prone positioning-assisted recruitment. Each maneuver is described with step-by-step procedures, parameter settings, monitoring targets, and termination criteria. Additionally, we present a structured approach to PEEP maintenance and de-escalation based on respiratory mechanics, gas exchange, and bedside imaging (e.g., Static Compliance, Electrical Impedance Tomography, or lung ultrasound). Dynamic assessment of oxygenation and compliance helps identify optimal PEEP and supports lung-protective ventilation. The protocol prioritizes patient safety, with criteria for preparation, exclusion, and real-time monitoring. This comprehensive guide supports standardized and individualized implementation of RMs and PEEP strategies in ARDS patients across critical care settings.

Introduction

Acute Respiratory Distress Syndrome (ARDS) is characterized by diffuse inflammation of the lung parenchyma, resulting in impaired gas exchange and an in-hospital mortality rate ranging from 33% to 52%¹. Mechanical ventilation remains the primary supportive strategy in patients with ARDS presenting with refractory hypoxemia. However, dependent atelectasis commonly develops due to increased lung tissue weight from interstitial and alveolar edema² . The interface between aerated and collapsed lung regions, along with cyclic tidal recruitment and derecruitment, imposes shear stress on alveolar units and contributes to ventil....

Protocol

NOTE: A variety of lung recruitment maneuvers (LRMs) are presented below. Clinical evaluation must be performed beforehand to ensure patient safety.

1. Preparations

1. Sedation and analgesia
   1. Administer adequate sedation and analgesia to minimize patient-ventilator asynchrony and to ensure that airway pressure accurately reflects lung mechanics. Achieve a Richmond Agitation-Sedation Scale (RASS) score of ≤ -3 before performing PEEP titration maneuvers and evaluating static mechanics. Adjust sedation depth and administer neuromuscular blockade if necessary¹¹.

Results

We have summarized the commonly used methods for lung recruitment and PEEP titration in clinical practice (Table 2 and Table 3). Each approach has distinct advantages and limitations, and the optimal strategy should be tailored to individual patient conditions and physiological responses.

RMs should be comprehensively assessed using a combination of physiological, mechanical, and imaging parameters. Key evaluation metrics include:1) Gas exchange: Improvement i.......

Discussion

RMs and PEEP Titration are key strategies in mechanical ventilation to optimize oxygenation and reduce ventilator-induced lung injury (VILI). RMs involve temporarily applying high airway pressures (such as sustained inflation or incremental PEEP) to reopen collapsed alveoli, improving lung homogeneity. Meanwhile, PEEP titration aims to identify the minimum effective PEEP level required to maintain alveolar recruitment while balancing the benefits of reopening against the risks of overdistension. The adjustment of PEEP af.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Ventilator	Mindray	Mindray SV850
EIT	Dräger	Swisstom BB2
Ultrasound Machine	Mindray	M9