Mild hypothermia versus normothermia in patients undergoing cardiac surgeryCentral MessagePerspective
Valentino Bianco, DO, MPH,
Arman Kilic, MD,
Edgar Aranda-Michel, BS,
Courtenay Dunn-Lewis, PhD,
Derek Serna-Gallegos, MD,
Shangzhen Chen, MPH,
Forozan Navid, MD,
Ibrahim Sultan, MD
Affiliations
Valentino Bianco, DO, MPH
Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa
Arman Kilic, MD
Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa; Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pa
Edgar Aranda-Michel, BS
Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa
Courtenay Dunn-Lewis, PhD
Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa
Derek Serna-Gallegos, MD
Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa; Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pa
Shangzhen Chen, MPH
Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pa
Forozan Navid, MD
Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa; Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pa
Ibrahim Sultan, MD
Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa; Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pa; Address for reprints: Ibrahim Sultan, MD, Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Pittsburgh, Center for Thoracic Aortic Disease, Heart and Vascular Institute, University of Pittsburgh Medical Center, 5200 Centre Ave, Suite 715, Pittsburgh, PA 15232.
Objective: Temperature during cardiopulmonary bypass (CPB) for cardiac surgery has been controversial. The aim of the current study is to compare the outcomes for patients with mild hypothermia versus normothermic CPB temperatures. Methods: All patients who underwent cardiac surgery with CPB and temperatures ≥32°C from 2011 to 2018 were included, which consisted of mild hypothermia (32°C-35°C) and normothermia (>35°C) cohorts. Propensity matching (1:1) was performed for risk adjustment. Primary outcomes included operative and long-term survival. Secondary outcomes included postoperative complications. Results: A total of 6525 patients comprised 2 cohorts: mild hypothermia (32°C-35°C; n = 3148) versus normothermia (>35°C; n = 3377). Following adjustment for surgeon preference, there were 1601 propensity-matched patients who had similar baseline characteristics (standard mean difference, ≤0.10), including CPB time, crossclamp time, and intra-aortic balloon pump placement. Kaplan-Meier analysis showed no difference in long-term survival (82.6% vs 81.6%; P = .81). Over a median follow-up of 4.4 years, there were no differences in overall mortality (18.1% vs 18.1%; P = 1.1) or readmission (50.3% vs 48.3%; P = .2). Acute renal failure (3.7% vs 2.4%; P = .03) and intensive care unit hours (46.5 vs 45.1; P = .04) were significantly higher with hypothermia. There was no difference between cohorts for postoperative stroke (2.0% vs 2.0%; P = 1.0), reoperation (5.9% vs 6.0%; P = .9), or operative intra-aortic balloon pump placement (1.7% vs 1.8%; P = .9). Conclusions: Patients with mild hypothermia during CPB had increased postoperative renal failure and length of intensive care unit stay. Although there was no difference in long-term survival, mild hypothermia does not appear to offer patients appreciable benefits, compared with normothermia.
