Performance of SAPS II and SAPS III scores in post-cardiac arrest.

BACKGROUND: Cardiac arrest is a major public health issue affecting an estimated 300,000 patients in the United States each year. The American Heart Association has recommended the Simplified Acute Physiology Score II and III (SAPS) to assess severity of illness and to predict outcomes in the post-cardiac arrest population. Our objective was to determine if SAPS II and SAPS III scores predict outcomes in post-cardiac arrest patients. METHODS: We performed an observational study of patients suffering cardiac arrest with return of spontaneous circulation. Data were collected prospectively and recorded in the Utstein style. SAPS II and SAPS III scores were calculated for each subject. Logistic regression was used to assess the relationship between the calculated severity of illness score and in-hospital mortality and poor neurologic outcome. RESULTS: A total of 274 subjects were identified for analysis. SAPS II was a significant predictor of in-hospital mortality (OR: 1.05, 95% CI: 1.03-1.07) and poor-neurologic outcome (OR: 1.06, 95%CI: 1.04-1.08). SAPS III was a significant predictor of in-hospital mortality (OR: 1.04, 95%CI: 1.02-1.06) and poor neurologic outcome (OR: 1.04, 95%CI: 1.02-1.05). Both scores had moderate ability to discriminate survivors from non-survivors (SAPS II AUC: 0.70; SAPS III AUC: 0.66), and good neurologic outcome from poor neurologic outcome (SAPS II AUC: 0.71; SAPS III AUC: 0.65). CONCLUSION: SAPS II and SAPS III scores have only moderate discrimination and are not clinically relevant tools to predict outcome in post-cardiac arrest patients. Further study is needed to identify a more reliable severity of illness score in the post-arrest population.

The association of lactate and vasopressor need for mortality prediction in survivors of cardiac arrest.

BACKGROUND: Currently there are few tools available for clinicians to predict outcomes in cardiac arrest survivors. Our objective was to determine if the combination of simple clinical parameters (initial blood lactate and vasopressor use) can predict outcome in post-cardiac arrest patients. METHODS: The design was a retrospective medical record review. The study was carried on in two urban, tertiary-care, university teaching hospitals. As for patients, inclusion criteria were: 1) age ≥18 years; 2) non-traumatic out-of-hospital cardiac arrest with return of spontaneous circulation; 3) lactic acid measured within one hour of return of circulation. No interventions was performed. RESULTS: Patients were divided into groups based on two variables: 1) vasopressor status (receipt of vasopressors vs. no vasopressors); and 2) initial blood lactate (categories defined as lactate <5 mmol/L, lactate 5 to 10 mmol/L, lactate ≥10 mmol/L); 128 out-of-hospital cardiac arrest patients met study inclusion criteria. Overall mortality was 71% (95%CI 63-79%). Patients who received vasopressors had significantly higher mortality rates compared to patients who did not receive vasopressors (80% vs. 52%; P=0.002). A stepwise increase in mortality is associated with increasing lactate levels (39% lactate <5 mmol/L, 67% lactate 5 mmol/L to10 mmol/L, and 92% lactate ≥10 mmol/L; P<0.001). The AUC for our model was 0.82. CONCLUSION: The combination of two clinical parameters, vasopressor need and lactic acid levels, is an accurate severity of illness classification system and can predict mortality in patients following out-of-hospital cardiac arrest. Prospective validation of these variables in post-cardiac arrest is needed.