Table 5

Logistic regression analysis of independent risk factors for PSV failure

ParameterUnivariate analysisMultivariate analysis
OR (95% CI)p ValueOR (95% CI)p Value
Age (years)1.002 (0.983 to 1.022)0.830.77
APACHE II1.035 (0.984 to 1.089)0.180.61
Chronic respiratory disease1.037 (0.519 to 2.075)0.920.76
Chronic cardiovascular disease0.731 (0.374 to 1.428)0.360.8
Time to initiation of PSV (h)0.996 (0.982 to 1.011)0.630.57
RASS ≤31.533 (0.819 to 2.868)0.180.54
PEEP >5 cm H2O1.513 (0.783 to 2.923)0.220.52
PaO2:FiO2 ≤26 kPa1.841 (0.955 to 3.546)0.070.1
pH0.996 (0.993 to 0.998)0.0020.996 (0.993 to 0.998)0.002
PCO2 (kPa)1.146 (0.911 to 1.441)0.24
Respiratory acidosis2.060 (0.835 to 5.083)0.12
Cardiovascular instability1.829 (0.969 to 3.451)0.060.06
  • n=196. Missing data point for one of the predicting variables n=13.

  • APACHE II, Acute Physiology and Chronic Health Evaluation; FiO2, fraction of inspired oxygen; PaCO2, partial pressure arterial carbon dioxide; PaO2, partial pressure arterial oxygen; PEEP, positive end-expiratory pressure; PSV, pressure support ventilation; RASS, Richmond Agitation and Sedation Scale.