The predictive ability of SAPS II, APACHE II, SAPS III, and APACHE IV to assess outcome and duration of mechanical ventilation in respiratory intensive care unit

OBJECTIVES: The objective is to determine utility of SAPS II, APACHE II, SAPS III, and APACHE IV scoring system in assessing outcome in mechanically ventilated patients in respiratory intensive care unit and to predict duration of mechanical ventilation (MV). MATERIALS AND METHODS: A prospective observational study where 83 mechanically ventilated patients were grouped into Group 1 (n(1) = 40, NIV) and Group 2 (n(2) = 43, Invasive ventilation) was conducted. SAPS II, APACHE II, SAPS III, and APACHE IV scores based predicted mortality (PM) were collected at day 1, and day 3. Outcomes (on day 7) were grouped into negative and positive. (NIV-negative outcome = Home NIV, intubation or death; positive outcome = NIV free. Invasive group-positive outcome = Extubation; negative outcome = Death). Binary logistic regression was applied to predict duration of MV (> or < 5 days). RESULTS: The data were analyzed using SPSS version 17.0 trials comparisons of PM on day 1 with SAPS II (P < 0.05) and APACHE IV (P < 0.007) were significant predictors of clinical outcomes in Group 1 where as in Group 2, none of the system could predict significantly. On day 3, Group 1 analysis revealed SAPS II (P < 0.002), SAPS III (P < 0.03), and APACHE IV (P < 0.004) based PM as significant predictors of outcome. APACHE II (P < 0.05) and APACHE IV (P < 0.02) PM were significant in Group 2. On day 3, APACHE IV could significantly predict (P < 0.05) duration of MV (>5 or < 5) while A-a gradient (P < 0.09) predicted poorly in Group 1. In Group 2, APACHE IV was a poor predictor (P < 0.09). Two full logistic regression models were also formulated for both the groups. CONCLUSION: Study concludes that day 3 severity scores are more significant predictors of outcome and duration. APACHE IV scoring system was found more effective than other systems, not only significantly differentiating outcomes of MV but also predicting duration of NIV.