title: Effects of prone position on the oxygenation of patients with acute respiratory distress syndrome.
abstract: OBJECTIVE
  Acute respiratory distress syndrome (ARDS) is characterized by arterial hypoxemia, and prone position (PP) is one possible management strategy. The objective here was to evaluate the effects of PP on oxygenation.
  
  
  METHODS
  Non-randomized, open, prospective, controlled clinical trial, in a surgical intensive care unit at a tertiary university hospital.
  
  
  METHODS
  Forty-one ARDS patients underwent PP for three-hour periods. Arterial partial oxygen pressure (PaO2) was measured immediately before changing to PP, after 30, 60, 120 and 180 minutes in PP and 60 minutes after returning to dorsal recumbent position (DP). The paired-t and Dunnett tests were used.
  
  
  RESULTS
  A notable clinical improvement in oxygenation (> 15%) was detected in 78.0% of patients. This persisted for 60 minutes after returning to DP in 56% and lasted for 12 and 48 hours in 53.6% and 46.3%, respectively. Maximum improvement was seen after 30 minutes in 12.5% of responding patients and after 180 minutes in 40.6%. No statistically significant associations between PP response and age, gender, weight, PEEP level, tidal volume, respiratory rate, PaO2/FiO2 or duration of mechanical ventilation were detected. One accidental extubation and four cases of deterioration through oxygenation were detected. The 48-hour mortality rate was 17%.
  
  
  CONCLUSIONS
  For a significant number of ARDS patients, PP may rapidly enhance arterial oxygenation and its inclusion for management of severe ARDS is justified. However, it is not a cost-free maneuver and caution is needed in deciding on using PP.
authors.affiliation: Intensive Care Unit, Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Heloisa Baccaro
authors.initials: HB
authors.lastname: Rossetti
authors.forename: Flávia Ribeiro
authors.initials: FR
authors.lastname: Machado
authors.forename: Jorge Luiz
authors.initials: JL
authors.lastname: Valiatti
authors.forename: José Luiz Gomes do
authors.initials: JL
authors.lastname: Amaral
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy; D011175:Positive-Pressure Respiration; D016684:Prone Position / Q000502:physiology*; D011446:Prospective Studies; D012128:Respiratory Distress Syndrome / Q000503:physiopathology / Q000628:therapy*; D017678:Sex Distribution; D013997:Time Factors