PT  - JOURNAL ARTICLE
AU  - Carlos Frederico Dantas Anjos
AU  - Guilherme Paula Pinto Schettino
AU  - Marcelo Park
AU  - Vladimir Silva Souza
AU  - Augusto Scalabrini Neto
TI  - A Randomized Trial of Noninvasive Positive End Expiratory Pressure in Patients With Acquired Immune Deficiency Syndrome and Hypoxemic Respiratory Failure
AID  - 10.4187/respcare.01268
DP  - 2012 Feb 01
TA  - Respiratory Care
PG  - 211--220
VI  - 57
IP  - 2
4099  - http://rc.rcjournal.com/content/57/2/211.short
4100  - http://rc.rcjournal.com/content/57/2/211.full
AB  - BACKGROUND: Acquired immunodeficiency syndrome (AIDS) is a pandemic disease commonly associated with respiratory infections, hypoxemia, and death. Noninvasive PEEP has been shown to improve hypoxemia. In this study, we evaluated the physiologic effects of different levels of noninvasive PEEP in hypoxemic AIDS patients. METHODS: Thirty AIDS patients with acute hypoxemic respiratory failure received a randomized sequence of noninvasive PEEP (5, 10, or 15 cm H2O) for 20 min. PEEP was provided through a facial mask with pressure-support ventilation (PSV) of 5 cm H2O and an FIO2 of 1. Patients were allowed to breathe spontaneously for a 20-min washout period in between each PEEP trial. Arterial blood gases and clinical variables were recorded after each PEEP treatment. RESULTS: The results indicate that oxygenation improves linearly with increasing levels of PEEP. However, oxygenation levels were similar regardless of the first PEEP level administered (5, 10, or 15 cm H2O), and only the subgroup that received an initial treatment of the lowest level of PEEP (ie, 5 cm H2O) showed further improvements in oxygenation when higher PEEP levels were subsequently applied. The PaCO2 also increased in response to PEEP elevation, especially with the highest level of PEEP (ie, 15 cm H2O). PSV of 5 cm H2O use was associated with significant and consistent improvements in the subjective sensations of dyspnea and respiratory rate reported by patients treated with any level of PEEP (from 0 to 15 cm H2O). CONCLUSIONS: AIDS patients with hypoxemic respiratory failure improve oxygenation in response to a progressive sequential elevation of PEEP (up to 15 cm H2O). However, corresponding elevations in PaCO2 limit the recommended level of PEEP to 10 cm H2O. At a level of 5 cm H2O, PSV promotes an improvement in the subjective sensation of dyspnea regardless of the PEEP level employed.