Perioperative hypothermia may be due to direct anesthetic inhibition of thermoregulation, decreased metabolism and loss of heat to the cold environment of operating rooms, even with active warming. When it is inadvertent, it may be associated to several complications, but when adequately indicated, it may protect vital organs such as central nervous system and heart. Normothermia decreases undesirable hypothermia effects, being warming the most effective preventive method. Active or passive warming approaches should be adopted and muscle shivering should be adequately treated to prevent discomfort and increased metabolic demand.

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SUMMARYThe purpose of this prospective, quantitative, comparative study, conducted at the 55 bed cardiothoracic intensive care unit of the Heart Institute (InCor), University of Sao Paulo Medical School, was to identify factors involved in the weaning of patients who require long-term (> 10 days) mechanical ventilation after cardiac surgery.The subjects included all patients who underwent open-heart surgery with cardiopulmonary bypass during a 10 month period from April 2000 to January 2001 (n = 946). From this group, 52 (5.7%) patients who required a tracheotomy for the management of long-term mechanical ventilation after cardiac surgery with cardiopulmonary bypass were selected. Pre-, intra-and postoperative data from patients who were not successfully weaned after reintubation and who underwent an elective tracheotomy were compared.Parameters of respiratory mechanics such as respiratory complications, oxygenation, and cardiac, renal, and neurological function were evaluated. Weaning success was defined as the ability of a patient to tolerate 48 hours without pressure or flow support from a mechanical ventilator. A patient was considered to have failed weaning if they died or remained under ventilation for more than 8 weeks. Of the 52 patients studied, 25 were successfully weaned, 21 died, and 6 remained ventilated for more than 8 weeks. We found significant statistical differences (P <0.05) between the groups with respect to success or failure in LVEF (P = 0.0035), the need for vasoactive agents (P = 0.0018), and renal failure (P = 0.002). Parameters of respiratory mechanics and oxygenation (eg, static airway compliance, airway resistance) did not influence the success or failure of weaning. There was a significant difference in relation to the presence of pneumonia (P = 0.0086) between the two groups. Although neurological complications were more frequent in patients in the weaning success group, the failure group had lower GCS scores, which is indicative of worse prognoses.It is concluded that cardiac dysfunction, the need for dialysis, and pneumonia are determinants for weaning failure in patients undergoing long-term mechanical ventilation after cardiac surgery. (Int Heart J 2005; 46: 819-831)

OBJECTIVE:Cancer patients frequently require admission to intensive care unit. However, there are a few data regarding predictive factors for mortality in this group of patients. The aim of this study was to evaluate whether arterial lactate or standard base deficit on admission and after 24 hours can predict mortality for patients with cancer.METHODS:We evaluated 1,129 patients with severe sepsis, septic shock, or postoperative after high-risk surgery. Lactate and standard base deficit collected at admission and after 24 hours were compared between survivors and non-survivors. We evaluated whether these perfusion markers are independent predictors of mortality.RESULTS:There were 854 hospital survivors (76.5%). 24 h lactate >1.9 mmol/L and standard base deficit < -2.3 were independent predictors of intensive care unit mortality. 24 h lactate >1.9 mmol/L and 24 h standard base deficit < -2.3 mmol/Lwere independent predictors of hospital death.CONCLUSION:Our findings suggest that lactate and standard base deficit measurement should be included in the routine assessment of patients with cancer admitted to the intensive care unit with sepsis, septic shock or after high-risk surgery. These markers may be useful in the adequate allocation of resources in this population.

A lot has been said about cognitive function disorders after heart surgeries, such as myocardial revascularization, which are present causes of increased morbidity and mortality, in addition to longer hospital stay. Major advances to decrease such rates have been observed in this field, and others are still expected aiming at neurological injuries prevention.