HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Permissions Request Permissions Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (13) Citing Articles via Google Scholar Google Scholar Articles by Mentzelopoulos, S. D. Articles by Zakynthinos, S. G. Search for Related Content PubMed PubMed Citation Articles by Mentzelopoulos, S. D. Articles by Zakynthinos, S. G.

Prone position reduces lung stress and strain in severe acute respiratory distress syndrome

¹ University of Athens Medical School, Dept of Intensive Care Medicine, Attikon University Hospital, and ² University of Athens Medical School, Dept of Intensive Care Medicine, Evaggelismos General Hospital, Athens, Greece

CORRESPONDENCE: S. D. Mentzelopoulos, 12 Ioustinianou Street, GR-11473, Athens, Greece. Fax: 30 2103218493. E-mail: sdm@hol.gr

Keywords: Acute respiratory distress syndrome, gas exchange, lung recruitment, mechanical ventilation, mechanics of the respiratory system, prone position

Received: September 9, 2004
Accepted November 19, 2004

The present authors hypothesised that in severe acute respiratory distress syndrome (ARDS), pronation may reduce ventilator-induced overall stress (i.e. transpulmonary pressure (P_L)) and strain of lung parenchyma (i.e. tidal volume (V_T)/end-expiratory lung volume (EELV) ratio), which constitute major ventilator-induced lung injury determinants. The authors sought to determine whether potential pronation benefits are maintained in post-prone semirecumbent (SR_PP) posture under pressure-volume curve-dependent optimisation of positive end-expiratory pressure (PEEP).

A total of 10 anesthetised/paralysed, mechanically ventilated (V_T = 9.0±0.9 mL·kg^–1 predicted body weight; flow = 0.91±0.04 L·s^–1; PEEP = 9.4±1.3 cmH₂O) patients with early/severe ARDS were studied in pre-prone semirecumbent (SR_BAS), prone, and SR_PP positions. Partitioned respiratory mechanics were determined during iso-flow (0.91 L·s^–1) experiments (V_T varied within 0.2–1.0 L), along with haemodynamics, gas exchange, and EELV.

Compared with SR_BAS, pronation/SR_PP resulted in reduced peak/plateau P_L at V_Ts0.6 L; static lung elastance and additional lung resistance decreased and chest wall elastance (in prone position) increased; EELV increased (23–33%); V_T/EELV decreased (27–33%); arterial oxygen tension/inspiratory oxygen fraction and arterial carbon dioxide tension improved (21–43/10–14%, respectively), and shunt fraction/physiological dead space decreased (21–50/20–47%, respectively).

In early/severe acute respiratory distress syndrome, pronation under positive end-expiratory pressure optimisation may reduce ventilator-induced lung injury risk. Pronation benefits may be maintained in post-prone semirecumbent position.

This article has been cited by other articles:

				T. D. Girard and G. R. Bernard Mechanical Ventilation in ARDS: A State-of-the-Art Review Chest, March 1, 2007; 131(3): 921 - 929. [Abstract] [Full Text] [PDF]

				S. D. Mentzelopoulos, C. Roussos, and S. G. Zakynthinos Prone Position in Early and Severe Acute Respiratory Distress Syndrome: A Design for a Definitive Randomized Controlled Trial Anesth. Analg., February 1, 2007; 104(2): 466 - 468. [Full Text] [PDF]