[Identification of patients with a high risk of needing prolonged mechanical ventilation after coronary surgery]. / Identicación de pacientes con mayor riesgo de precisar ventilación mecánica prolongada tras cirugía coronaria.

OBJECTIVES: To identify patients at greater risk of developing respiratory complications, defined as the need for mechanical ventilation (MV) longer than 48 h, following revascularization surgery. MATERIAL AND METHODS: This was a prospective analysis of 39 variables in 107 consecutive operations taking place over 9 months. We studied the association of these variables with the need for prolonged MV after surgery, by way of single variable and multivariate analysis. RESULTS: The incidence of prolonged MV was 7.7% and the 25% rate of mortality in the group of patients with this complication was significantly higher than the 0% mortality in the remaining patients. After single variable analysis of the data, the following variables were more significantly (p < 0.01) associated with the need for postoperative MV longer than 48 h: presence of other cardiac lesions other than coronary disease, performance of other heart surgery along with the coronary revascularization, surgical complications, high left auricular pressure soon after surgery. The variables found to have the highest independent predictive value based on the multivariate analysis were performance of other heart surgery along with the coronary revascularization and surgical complications. CONCLUSION: Our study indicates that the variables that point to poor left ventricular function and negative repercussions on extracorporeal circulation are associated with a greater incidence of prolonged MV after coronary surgery. Keeping these variables in mind allows high risk patients to be identified. More extensive monitoring of breathing function and therapeutic measures can then be implemented for better postoperative management.

Caloric supply in parenteral nutrition in the stress phase.

Due to the metabolic alterations following surgery, glucose is not completely oxidized but is converted into glycogen and lipids. Therefore we analysed 2 groups of 15 patients following surgery. They received parenteral nutrition with identical nitrogen (N = 0.28 g/kg/d) and lipid (1.5 g/kg/d) intake, whereby only the composition of carbohydrates was varied. Group I received exclusively glucose = 0.22 g/kg/h, and group II the combination fructose-glucose-xylitol in a proportion of 2:1:1 at the same infusion rate. The study lasted approximately 10 days. We found decreased exogenous insulin requirements and an increase in the NEFA levels with a maximum on the 3rd and 4th day in group II. There were no significant differences in the levels of either albumin, prealbumin or retinol-binding protein, nor were any hepatic or renal alterations related to the xylitol infusion observed. Xylituria was 6.13 +/- 3% of the amount infused. In our opinion, the partial substitution of glucose in group II led to a better utilisation of the infused energy supply, and to less insulin stimulation, which facilitated the mobilization of endogenous energy sources such as fatty acids, although we did not succeed in increasing the protein synthesis.