Novel thermoregulation system for enhancing cardiac function and hemodynamics during coronary artery bypass graft surgery

Background. Myocardial ischemia, arrhythmias, and coagulopathies are associated with postoperative hypothermia. This study assessed the efficacy of a novel thermoregulation system in alleviating these events during coronary artery bypass graft (CABG) surgery. Methods. Elective CABG surgery patients were randomized into either Allon thermoregulation (AT, n = 40) or routine thermal care (RTC, n = 20) groups in whom the maintenance of normothermia during the nonbypass phases of the operation was compared. The AT used patients' rectal temperature as reference data to monitor the maintenance of the water temperature circulating at 37°C in a garment. Rectal temperature, patient hemodynamics, and cardiac-specific troponin I (cTnI) levels were assessed at the induction of anesthesia, 30 minutes into surgery, at discontinuation of bypass, end of surgery, and 2 hours postoperatively. Results. Body temperature was higher in the AT group compared to the RTC group at all five time points. Cardiac index (CI) (L/min) was higher in the AT group, 2.5 ± 0.5, 2.6 ± 0.5*, 3.2 ± 0.6*, 3.3 ± 0.5*, 3.1 ± 0.7 at the respective time points, compared to the RTC group, 2.3 ± 0.6, 2.1 ± 0.2, 2.6 ± 0.7, 2.7 ± 0.7, 2.7 ± 0.7 (*p < 0.05). Systemic vascular resistance (SVR) (dyne · s)/cm⁵) was consistently lower in the AT patients. Enzyme levels were elevated in both groups but were less so in the AT patients. Conclusions. The AT system can efficiently maintain normothermia. The beneficial effects are expressed by reduced SVR, elevated CI, and lower levels of cTnI, which may show a possible attenuation of myocardial injury.