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

A new bronchial blocker tube for one-lung ventilation

One-lung ventilation is used to facilitate thoracic and cardiac surgery. This article describes the development and clinical use of a new device, the bronchial blocker tube, to establish one-lung ventilation. The bronchial blocker tube has two circular lumen joined together, one for ventilation and one for acceptance of a bronchial blocker. In this setting, the bronchial blocker is a separate device which is replaceable, rotatable, and removable. In the authors' experience, the bronchial blocker tube was effective and easy to use.

Dexamethasone decreases the incidence of shivering after cardiac surgery: a randomized, double-blind, placebo-controlled study

Shivering after cardiac surgery is common, and may be a result of intraoperative hypothermia. Another possible etiology is fever and chills secondary to activation of the inflammatory response and release of cytokines by cardiopulmonary bypass. Dexamethasone decreases the gradient between core and skin temperature and modifies the inflammatory response. The goal of this study was to determine whether dexamethasone can reduce the incidence of shivering. Two hundred thirty-six patients scheduled for elective coronary and/or valvular surgery were randomly assigned to receive either dexamethasone 0.6 mg/kg or placebo after the induction of anesthesia. All patients received standard monitoring and anesthetic management. After arrival in the intensive care unit (ICU), nurses unaware of the treatment groups recorded visible shivering, as well as skin and pulmonary artery temperatures. Analysis of shivering rates was performed by using chi2 tests and logistic regression analysis. Compared with placebo, dexamethasone decreased the incidence of shivering (33.0% vs 13.1%; P = 0.001). It was an independent predictor of reduced incidence of shivering and was also associated with a higher skin temperature on ICU admission and a lower central temperature in the early postoperative period.

IMPLICATIONS

Dexamethasone is effective in decreasing the incidence of shivering. The effectiveness of dexamethasone is independent of temperature and duration of cardiopulmonary bypass. Shivering after cardiac surgery may be part of the febrile response that occurs after release of cytokines during cardiopulmonary bypass.

Lidocaine and the inhibition of postoperative pain in coronary artery bypass patients

OBJECTIVE

This study was designed to evaluate whether a continuous low-dose lidocaine infusion reduces postoperative pain and anxiety in patients undergoing coronary artery bypass grafting (CABG) and to retrospectively examine time to extubation, intensive care unit stay (ICU), and hospital length of stay.

DESIGN

A double-blinded, randomized, and prospective approach.

SETTING

Hospital patients undergoing first-time CABG.

PARTICIPANTS

After informed consent, 100 patients were enrolled in this study.

INTERVENTIONS

Lidocaine infusion or placebo substitute was begun after induction of anesthesia. The fentanyl/midazolam infusion was discontinued on ICU admission; lidocaine or placebo continued until ICU discharge. Supplemental fentanyl, midazolam, or propranolol was administered for pain, anxiety, or hemodynamic stress.

MEASUREMENTS AND MAIN RESULTS

Drug dosages were compared between groups. Postoperative assessment included visual analog pain score, hemodynamics, sedation score, and nursing assessment. Mean total dosages of fentanyl, midazolam, and propranolol between the lidocaine and placebo groups were 620.40 +/- 815.74 microgram versus 689.16 +/- 692.99 microgram, p = 0.244; 0.54 +/- 1.13 mg versus 1.20 +/- 2.44 mg p = 0.465; 0.11 +/- 0.75 mg versus 3.56 +/- 17.2 mg, p = 0.564, respectively. Times to extubation, ICU length of stay, and hospital stay did not achieve statistical significance.

CONCLUSIONS

Continuous infusion of low-dose lidocaine did not significantly decrease supplemental fentanyl, midazolam, or propranolol requirement postoperatively. Similarly, a lidocaine infusion does not result in reduced time to extubation. ICU stay, or hospital length of stay.