Impact of postoperative hypothermia on outcomes after off-pump coronary artery bypass grafting

Abstract

Background Even though the physiological derangements caused by hypothermia are well described, there is no consensus about its impact on postoperative outcomes. The aim of this study is to assess the effect of postoperative hypothermia on outcomes after off-pump coronary artery bypass surgery. Methods A total of 1979 patients undergoing isolated off-pump coronary artery bypass surgery in a single center in the period 2007–2018 were classified according to their axillary temperature measurement at intensive care unit admission postoperatively to either hypothermic (<36°C) or normothermic (≥36°C). Between-group differences on baseline characteristics and postoperative outcomes were assessed before and after propensity score matching. Results Data analysis showed that 582 patients (29.4%) were hypothermic (median temperature 35.5°C) and 1397 patients (70.6%) were normothermic (median temperature 36.4°C). Using propensity score matching, 567 patient pairs were created. Patients with hypothermia exhibited a higher rate of postoperative transfusion of at least three red cell concentrate units (14.3% vs 9%, p = 0.005), a longer intubation duration (median duration, 6 vs 5 h, p < 0.0001), and a longer intensive care unit stay (median stay, 1.6 vs 1.3 days, p = 0.008). There was no difference in reoperation for bleeding, renal replacement therapy, infections, and mortality between the two groups. Conclusions Even though associated with a higher blood transfusion requirement and a slightly longer intensive care unit stay, mild postoperative hypothermia was not associated with a higher morbidity and mortality.

Low body temperature and mortality in critically ill patients with coronary heart disease: a retrospective analysis from MIMIC-IV database

“…Likewise, Nam et al [ 20 ] reported that the all-cause mortality of moderate-to-severe hypothermia was more than two times of that in normothermia for off-pump CABG patients and even mild hypothermia (no less than 35.5℃) was found an unsatisfied outcome during the follow-up of 47 months. However, another study that enrolled isolated off-pump CABG patients showed no statistically difference for in-hospital mortality between hypothermia group and normothermia group neither before nor after propensity score matching, while a distinction in postoperative transfusion of red cell concentrates, duration of intubation and ICU stay [ 15 ]. Unexpectedly, there was a higher rate of in-hospital mortality in the normothermia group than in the hypothermia group after pairing, though this difference was not statistically significant ( P = 0.975 vs. P = 0.244).…”

“…Whether temperature abnormalities have an influence on CHD patients remains unknown yet, so we hypothesized low body temperature was linked with worse outcome based on similar investigations aiming at patients undergoing coronary artery bypass grafting (CABG) [ 14 , 15 ] and other cardiac surgeries [ 16 ]. And we tested this in the Medical Information Mart for Intensive Care (MIMIC)-IV database in a pre-specified manner.…”

Hybrid operating rooms and the risk of postoperative hypothermia in pregnant women with placenta previa: A retrospective cohort study

“…For the primary outcome, we conducted univariate logistic regression analyses on variables known to be risk factors for postoperative hypothermia, including age, operation duration [ 18 ], body mass index [ 19 ], intraoperative fluid, intraoperative bleeding and transfusion [ 20 ], as well as surgeries performed in the Hybrid OR. Age and operation duration were categorized based on the median values of the entire dataset, while body mass index, intraoperative fluid, and intraoperative bleeding were categorized based on the 25th and 75th percentiles; intraoperative transfusion was categorized by the number of transfused packs.…”

Reliability of different body temperature measurement sites during normothermic cardiac surgery

“…3,4 Physiological derangements caused by hypothermia and its impact on postoperative outcomes are well described (increased incidence of coagulopathy, bleeding and wound infections, a greater risk of cardiovascular complications, a longer intensive care unit stay, and increased costs). [5][6][7] On the other hand, hyperthermia during cardiac surgery has been associated with increased risk of postoperative neurocognitive dysfunction and kidney damage, especially when temperatures exceeding 37°C during rewarming. [8][9][10][11][12] Hyperthermia, even if mild, aggravates ischemic neuronal injury and accelerates neuronal death.…”