Association between postoperative hypothermia and adverse outcome after coronary artery bypass surgery.

BACKGROUND: We examined the effect on outcome of mild hypothermia (< 36 degrees C) upon intensive care unit (ICU) admission on patient outcome after coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). METHODS: We performed a retrospective database analysis of 5,701 isolated CABG patients requiring CPB, operated upon from January 1995 to June 1997. Patients were classified as either hypo- (< 36 degrees C) or normothermic (> or = 36 degrees C) upon ICU admission. ICU admission bladder core temperature (BCT) versus outcome was evaluated. Outcome measures included mortality, resource utilization (mechanical ventilation time, ICU and hospital length of stay, and postoperative packed red blood cell transfusion), and major morbidity (cardiac, renal, neurologic, or major infection). RESULTS: Overall, patients admitted to the ICU with BCT < 36 degrees C had a significantly greater mortality (p = 0.02), prolonged mechanical ventilation (p = 0.007), packed red blood cell transfusion (p = 0.001), ICU (p = 0.01), and hospital (p = 0.005) length of stay. CONCLUSIONS: BCT of less than 36 degrees C, upon ICU admission, has a significant association with adverse outcome after CABG with CPB. M An __ Tl QA_7_t-0

Trace eyeblink conditioning in the freely moving rat: optimizing the conditioning parameters.

Trace eyeblink conditioning (EBC) parameters, with an airpuff unconditioned stimulus, were examined in male Fischer 344 X Brown Norway F1 rats. Integrated electromyographic activity from the upper eyelid was recorded. An 8-kHz tone was superior to white noise as a conditioning stimulus. Rats trained with 30 or 50 trials per session showed similar learning. Reversal of environmental lighting had no significant effect. Trace intervals of 0 and 250 ms yielded well-timed conditioned responses (CRs); intervals of 500 ms or more did not. These experiments provide parameters that reliably yield CRs and suggest limits on the temporal processing capabilities of the rat. EBC can thus be used as part of a comprehensive test battery for learning and memory in this species. Physiological recording and pharmacological manipulations may also be done easily. This combination of approaches should facilitate a more complete understanding of learning mechanisms and age-related memory impairments.

Perioperative management and outcome of patients having cardiac surgery combined with abdominal aortic aneurysm resection.

Patients with abdominal aortic aneurysms (AAA) have a high incidence of associated cardiac disease. If a patient presents with both severe coronary artery disease and a large AAA, a staged procedure of cardiac surgery (CS) followed by AAA resection may present too great a risk of aneurysm rupture and death. A combined procedure may be recommended in this circumstance; however, the literature contains only individual successful case reports of such a procedure. A series of 10 patients who underwent CS and AAA repair to define the risks and outcome of this complex patient population is presented. Methods used included a retrospective analysis of hospital chart data from patients undergoing combined CS and AAA resection from 1980 to the present at this institution. The data analyzed included age, sex, chief complaint, past medical history, indications for surgery, abdominal aneurysm size, coronary anatomy, valvular pathology, preoperative left ventricular function, anesthetic agent and dose, order of surgery, prebypass complications, intraoperative complications, cardiopulmonary bypass time, aortic cross-clamp time, abdominal aortic cross-clamp time, blood product use, and postoperative complications. Seven of the 10 patients had a successful outcome (S group), whereas 3 of the 10 patients died postoperatively (D group). The staged procedure of first performing CS and then the AAA resection has a combined operative mortality of 4%. When the nature of both lesions is severe and a combined procedure is necessary, there is an associated in-hospital mortality of approximately 30% at this institution. The S group patients had an unremarkable postoperative course with a relatively short hospital stay when compared to the staged procedure.