The possible risk for strokes complicating cardiac surgery in patients with intraoperative hypothermia.
BACKGROUND
The effect of hypothermia as a possible neuroprotective tool on the outcome of cardiac surgery is still controversial.


METHODS
We retrospectively assessed all patients who underwent cardiac surgery within a 14-year period and compared patients with and without postoperative stroke.


RESULTS
Stroke occurred more frequently in patients who underwent valve repair/replacement combined with coronary artery bypass grafting (CABG) than in patients who had CABG alone (p = 0.0002). All strokes (1.4%) were ischemic and mostly of large-vessel etiology. All patients with stroke had intraoperative minimal temperature <34°C. More patients in this group than in the group without stroke had an intraoperative minimal temperature <30°C (p = 0.01). Stepwise multivariate analysis of all pre- and intraoperative parameters identified significant risk factors for stroke: hypertension, diabetes mellitus and previous stroke as preoperative risk factors, but only lower minimal temperature as a significant intraoperative risk factor (p = 0.03; odds ratio 1.080/1°C, 95% confidence interval 1.004-1.152). The mean intraoperative temperature was 28 ± 4°C in patients who developed stroke and 30 ± 3°C in patients without stroke.


CONCLUSIONS
Intraoperative hypothermia around 28°C might be harmful and associated with increased risk for postsurgical stroke.
Department of Neurology, Shaare Zedek Medical Center, Jerusalem, Israel. ikl@cc.huji.ac.il
Isabelle
I
Korn-Lubetzki
Israel
I
Steiner
Avraham
A
Oren
Rachel
R
Tauber
Bettina
B
Steiner-Birmanns
Daniel
D
Bitran
D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D016009:Chi-Square Distribution; D001026:Coronary Artery Bypass / Q000009:adverse effects; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects*; D007430:Intraoperative Care; D007557:Israel; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000209:etiology*