Mortality prediction in cardiac surgery patients: comparative performance of Parsonnet and general severity systems.

BACKGROUND: Our purpose was to assess the performance of general severity systems (Acute Physiology and Chronic Health Evaluation [APACHE], Simplified Acute Physiology Score [SAPS], and Mortality Probability Models [MPM]) and to compare them with the Parsonnet score to predict mortality after cardiac surgery. METHODS AND RESULTS: This was a prospective observational study of 465 cardiac surgery patients in a tertiary referral center. Probabilities of hospital death for patients were estimated by applying the 4 models and were compared with actual mortality rates. Performance of the 4 systems was assessed by evaluating calibration with the Hosmer-Lemeshow goodness-of-fit test and discrimination with receiver operating characteristic (ROC) curves. chi2 values were 3. 71 for Parsonnet, 4.52 for MPM II0, 4.30 for MPM II24, 5.16 for SAPS II, and 10.57 for APACHE II. The area under the ROC curve was 0.857 for Parsonnet, 0.783 for MPM II0, 0.796 for MPM II24, 0.771 for SAPS II, and 0.803 for APACHE II. CONCLUSIONS: In our experience, the Parsonnet score performs very well, with calibration and discrimination very high, better than general severity systems, and it is an appropriate tool to assess mortality in cardiac surgery patients. In our experience, the general severity systems perform well to predict mortality after cardiac surgery, with high calibration of MPM II24, MPM II0, and SAPS II; minor calibration for APACHE II; and high discrimination for 3 general systems, but not as well as the Parsonnet score.

[Enteral nutrition in ICU patients on a high-protein diet]. / Nutrición enteral en pacientes de UCI con dieta hiperproteica.

BASIS: The need for nutritional support is at present beyond question, while the use of early enteral nutrition in critical patients admitted to Intensive Care Units is increasingly common and would appear to offer a set of advantages as nutritional support. PATIENTS: Of a total of 26 consecutive enteral nutrition patients, 22 were studied prospectively (84.6%), and, through a nasal-gastric probe, were administered early high protein enteral polymeric diet with 25% of total calorific value from proteins, for an average of 10 days. The other four (15.4%) did not enter the study, according to the exclusion criteria established, and so were not taken into account in the statistics. METHOD: A design was followed in which the diet was administered progressively until reaching 30 ml/kg/day, in a maximum of three days, during which aspects were analyzed dealing with tolerance and ease of use, on the one hand, and other metabolic and nutritional aspects on the other. Analytical controls were carried out on days 0, 4, 8 and 12. Tolerance and adverse effects were monitored continuously. RESULTS: During the study, one of the twenty-two patients died (4.54%): the other 21 remained alive. In analysis of the metabolic and nutritional parameters, improvement was obtained in all those expected to reach normal levels, with p < 0.001 (glucose, prealbumin, TF, RBP, Zn, Mg and P). Of particular note was the evolution of the nitrogen balance (p < 0.001 and r = 0.77). As to tolerance, diarrhea appeared in two patients (9.09%), ileus in one (4.5%): no cases were detected of abdominal distension, nausea or vomiting. In no case was diet suspended for causes attributable to the enteral nutrition, nor was any therapeutic manipulation required. CONCLUSIONS: Excellent tolerance of enteral nutrition was obtained, with almost no complications associated with its use, despite the gravity of the patients (APACHE 14). On the other hand, an improvement was obtained in metabolic and nutritional parameters, with the particular significance of the nitrogen balance.