Intensive Care Medicine

, Volume 34, Issue 10, pp 1766–1773

Airway pressure release ventilation and biphasic positive airway pressure: a systematic review of definitional criteria


DOI: 10.1007/s00134-008-1216-3

Cite this article as:
Rose, L. & Hawkins, M. Intensive Care Med (2008) 34: 1766. doi:10.1007/s00134-008-1216-3



The objective of this study was to identify the definitional criteria for the pressure-limited and time-cycled modes: airway pressure release ventilation (APRV) and biphasic positive airway pressure (BIPAP) available in the published literature.


Systematic review.


Medline, PubMed, Cochrane, and CINAHL databases (1982–2006) were searched using the following terms: APRV, BIPAP, Bilevel and lung protective strategy, individually and in combination. Two independent reviewers determined the paper eligibility and abstracted data from 50 studies and 18 discussion articles.

Measurements and results

Of the 50 studies, 39 (78%) described APRV, and 11 (22%) described BIPAP. Various study designs, populations, or outcome measures were investigated. Compared to BIPAP, APRV was described more frequently as extreme inverse inspiratory:expiratory ratio [18/39 (46%) vs. 0/11 (0%), P = 0.004] and used rarely as a noninverse ratio [2/39 (5%) vs. 3/11 (27%), P = 0.06]. One (9%) BIPAP and eight (21%) APRV studies used mild inverse ratio (>1:1 to ≤2:1) (P = 0.7), plus there was increased use of 1:1 ratio [7 (64%) vs. 12 (31%), P = 0.08] with BIPAP. In adult studies, the mean reported set inspiratory pressure (PHigh) was 6 cm H2O greater with APRV when compared to reports of BIPAP (P = 0.3). For both modes, the mean reported positive end expiratory pressure (PLow) was 5.5 cm H2O. Thematic review identified inconsistency of mode descriptions.


Ambiguity exists in the criteria that distinguish APRV and BIPAP. Commercial ventilator branding may further add to confusion. Generic naming of modes and consistent definitional parameters may improve consistency of patient response for a given mode and assist with clinical implementation.


Airway pressure release ventilation Acute lung injury Mechanical ventilation Positive pressure respiration Assisted spontaneous breathing Biphasic positive airway pressure 

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  1. 1.Lawrence S. Bloomberg Faculty of NursingUniversity of TorontoTorontoCanada
  2. 2.Intensive Care UnitStirling Royal InfirmaryStirlingScotland, UK