Comparison of acute physiology and chronic health evaluation II and acute physiology and chronic health evaluation IV to predict intensive care unit mortality.

CONTEXT: Clinical assessment of severity of illness is an essential component of medical practice to predict the outcome of critically ill-patient. Acute Physiology and Chronic Health Evaluation (APACHE) model is one of the widely used scoring systems. AIMS: This study was designed to evaluate the Performance of APACHE II and IV scoring systems in our Intensive Care Unit (ICU). SETTINGS AND DESIGN: A prospective study in 6 bedded ICU, including 76 patients all above 15 years. SUBJECTS AND METHODS: APACHE II and APACHE IV scores were calculated based on the worst values in the first 24 h of admission. All enrolled patients were followed, and outcome was recorded as survivors or nonsurvivors. STATISTICAL ANALYSIS USED: SPSS version 17. RESULTS: The mean APACHE score was significantly higher among nonsurvivors than survivors (P < 0.005). Discrimination for APACHE II and APACHE IV was fair with area under receiver operating characteristic curve of 0.73 and 0.79 respectively. The cut-off point with best Youden index for APACHE II was 17 and for APACHE IV was 85. Above cut-off point, mortality was higher for both models (P < 0.005). Hosmer-Lemeshow Chi-square coefficient test showed better calibration for APACHE II than APACHE IV. A positive correlation was seen between the models with Spearman's correlation coefficient of 0.748 (P < 0.01). CONCLUSIONS: Discrimination was better for APACHE IV than APACHE II model however Calibration was better for APACHE II than APACHE IV model in our study. There was good correlation between the two models observed in our study.

Apnea testing with continuous positive airway pressure for the diagnosis of brain death in a patient with poor baseline oxygenation status.

Apnea testing is a key component in the clinical diagnosis of brain death. Patients with poor baseline oxygenation may not tolerate the standard 8-10 min apnea testing with oxygen insufflation through tracheal tube. No studies have assessed the safety and feasibility of other methods of oxygenation during apnea testing in these types of patients. Here, we safely performed apnea testing in a patient with baseline PaO2 of 99.1 mm Hg at 100% oxygen. We used continuous positive airway pressure (CPAP) of 10 cm of H2O and 100% oxygen at the flow rate of 12 L/min using the circle system of anesthesia machine. After 10 min of apnea testing, PaO2 decreased to 75.7 mm Hg. There was a significant rise in PaCO2 and fall in pH, but without hemodynamic instability, arrhythmias, or desaturation. Thus, the apnea test was declared positive. CPAP can be a valuable, feasible and safe means of oxygenation during apnea testing in patients with poor baseline oxygenation, thus avoiding the need for ancillary tests.

Influence of Arterial Blood Gas to Guide Extubation in Intensive Care Unit Patients after Spontaneous Breathing Trial.

BACKGROUND: Arterial blood gas is required for extubation decision after spontaneous breathing trial in most of intensive care unit. This study was conducted to assess the influence of arterial blood gas for extubation after successful spontaneous breathing trial in intensive care unit patients planned for extubation. METHODS: It was prospective observation study conducted in all patients of age greater than eighteen year admitted in intensive care unit of tertiary care hospital for one year. It was done in 108 patients who were planned for extubation. Patients were assessed by intensivist clinically and decided whether a patient can be extubated on clinical grounds. Spontaneous breathing trial was done for 2 hours by t-piece in patients who met clinical and objective criteria. Arterial blood gas was done in all patients who successfully completed spontaneous breathing trial. Patients with successful spontaneous breathing trial, acceptable arterial blood gas were extubated. Independent Student's t test and paired t test was used for data analysis. RESULTS: Out of 108 patients who passed the spontaneous breathing trial, 96(88.88%) patients had acceptable arterial blood gas and were extubated and 12(11.11%) patients did not have acceptable arterial blood gas level and were chosen to have other mode of weaning. CONCLUSIONS: This study demonstrates that arterial blood gas level has changed decision for extubation after successful spontaneous breathing trial. Further, arterial blood gas might help in identification of patients who can undergo extubation failure when rapid shallow breathing index failed to predict outcome of extubation.