Combined APACH II score and arterial blood lactate clearance rate to predict the prognosis of ARDS patients

Objective: To explore the easily applicable indicators of practical value to evaluate the prognosis of acute respiratory distress syndrome (ARDS). Methods: Blood and biochemical tests and blood-gas analyses were performed upon entry into the ICUs, 12 h, 24 h, 48 h and 72 h after that in 72 ARDS patients (who were admitted to the ICUs of our hospital from January 2000 to December 2009). Then APACHE II scores were achieved by combining relevant physiological parameters and laboratory results. Results: There was a statistical difference between the death group and survival group at different time points upon entering the ICUs in terms of APACHE II score, alveolar-arterial oxygen difference and arterial blood lactate clearance rate. PaO2/FiO(2) values were recorded to be statistically different between the death group and survival group 24 h, 48 h and 72 h, respectively after entry into the ICUs. In addition, registered linear regression existed between APACHE II score, alveolar-arterial oxygen difference or PaO2/FiO(2) value and time. APACHE II score 24 h and 72 h after entering ICUs predicted mortality with an area under the ROC curve (AUC) standing respectively at 0.919 and 0.955. Arterial blood lactate clearance rate 12 h, 24 h, 48 h and 72 h after entering ICUs predicted mortality with an area under the ROC curve (AUC) at 0.918, 0.918, 0.909 and 0.991, respectively. Conclusions: APACHE II score applied in combination with arterial blood lactate clearance rate is of clinical significance in assessing the prognosis of ARDS patients.