Lung volumes and lung volume recruitment in ARDS: a comparison between supine and prone position

Hernan Aguirre-Bermeo,Olimpia Festa,Stefano Italiano,Jordi Mancebo,Maddalena Bitondo,Marta Turella,Juan Grandjean,Indalecio Morán

doi:10.1186/s13613-018-0371-0

Hernan Aguirre-Bermeo, Olimpia Festa + Show 6 more

Open Access

https://doi.org/10.1186/s13613-018-0371-0

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Abstract

BackgroundThe use of positive end-expiratory pressure (PEEP) and prone position (PP) is common in the management of severe acute respiratory distress syndrome patients (ARDS). We conducted this study to analyze the variation in lung volumes and PEEP-induced lung volume recruitment with the change from supine position (SP) to PP in ARDS patients.MethodsThe investigation was conducted in a multidisciplinary intensive care unit. Patients who met the clinical criteria of the Berlin definition for ARDS were included. The responsible physician set basal PEEP. To avoid hypoxemia, FiO2 was increased to 0.8 1 h before starting the protocol. End-expiratory lung volume (EELV) and functional residual capacity (FRC) were measured using the nitrogen washout/washin technique. After the procedures in SP, the patients were turned to PP and 1 h later the same procedures were made in PP.ResultsTwenty-three patients were included in the study, and twenty were analyzed. The change from SP to PP significantly increased FRC (from 965 ± 397 to 1140 ± 490 ml, p = 0.008) and EELV (from 1566 ± 476 to 1832 ± 719 ml, p = 0.008), but PEEP-induced lung volume recruitment did not significantly change (269 ± 186 ml in SP to 324 ± 188 ml in PP, p = 0.263). Dynamic strain at PEEP decreased with the change from SP to PP (0.38 ± 0.14 to 0.33 ± 0.13, p = 0.040).ConclusionsAs compared to supine, prone position increases resting lung volumes and decreases dynamic lung strain.

Highlights

The use of positive end-expiratory pressure (PEEP) and prone position (PP) is common in the manage‐ment of severe acute respiratory distress syndrome patients (ARDS)
Twenty-three patients were included in the study, and twenty were analyzed
Dynamic strain at PEEP decreased with the change from supine position (SP) to PP

Summary

Introduction

The use of positive end-expiratory pressure (PEEP) and prone position (PP) is common in the manage‐ment of severe acute respiratory distress syndrome patients (ARDS). The use of positive end-expiratory pressure (PEEP) and prone position (PP) is common in the manage‐. Acute respiratory distress syndrome (ARDS) is a permeability pulmonary edema, characterized by hypoxemia and a decrease in lung volumes and respiratory system compliance [1, 2]. In patients with ARDS, prone position (PP) produces a more homogeneous distribution of the inspired gas [3] and a better matching between ventilation and perfusion, thereby improving arterial oxygenation [3,4,5]. As compared to supine position (SP), the PP reduces the steep transpulmonary pressure gradient across the vertical axis of the lung, leading to a more homogeneous distribution of pulmonary stress and strain [2, 3, 13] The benefit on survival of PP is not related only to the improvement in gas exchange [9, 10], and the protective effect on ventilatorinduced lung injury [3, 9, 11, 12] could play a role.

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