Preoperative warming and undesired surgical and anesthesia outcomes in pediatric spinal surgery-a retrospective cohort study.
BACKGROUND
Underbody forced air warming is a method commonly used for intraoperative temperature maintenance in children. We previously reported that preoperative forced air warming of children undergoing spinal surgery substantially reduces the incidence and duration of intraoperative hypothermia (<36°C).


OBJECTIVE
The aim of this study was to evaluate the effects of preoperative warming before spinal deformity surgery on surgical site infection rate, length of hospitalization, and bleeding (estimated blood loss and incidence of cell salvaged and/or allogeneic packed red blood cell transfusions).


METHODS
Demographic, anesthetic, and surgical data of all patients who underwent spinal deformity surgery between December 2009 and December 2012 were obtained by retrospective chart review. Temperature data were abstracted from an existing repository; the incidence and duration of hypothermic episodes were identified. For each outcome, logistic regression models and propensity score analysis were used to estimate the effect of prewarming, adjusted for potential confounders. The issue of missing data was handled by a multiple imputation method. Data from 334 procedures were used in modeling and propensity score stratification.


RESULTS
Adjusted odds ratios for the effects of prewarming were 0.47 (95% CI 0.15-1.49) for surgical site infections; 0.89 (95% CI 0.55-1.41) for cell salvaged blood transfusion; 0.43 (95% CI 0.22-0.83) for allogeneic packed red blood cell transfusion; and 1.24 (95% CI 0.77-1.99) for a length of hospitalization >6 days. Adjusted mean decrease in estimated blood loss for prewarming was 72 (95% CI -29 to 173) ml.


CONCLUSIONS
In this study, prewarming was associated with a reduction in allogeneic packed red blood cell transfusion. However, no causal relationship between prewarming and reduced allogeneic blood transfusion should be assumed. Prewarming was not associated with reductions in estimated blood loss, length of hospitalization, or the incidence of surgical site infection.
Department of Anesthesiology, Pharmacology and Therapeutics, The University of British Columbia, Vancouver, BC, Canada.|Pediatric Anesthesia Research Team, Child and Family Research Institute, Vancouver, BC, Canada.
Matthias
http://orcid.org/0000-0003-2193-178X
M
Görges
Department of Anesthesiology, Pharmacology and Therapeutics, The University of British Columbia, Vancouver, BC, Canada.
Nicholas C
NC
West
Department of Anesthesiology, Pharmacology and Therapeutics, The University of British Columbia, Vancouver, BC, Canada.|School of Medicine and Dentistry, The University of Aberdeen, Aberdeen, Scotland.
Wesley
W
Cheung
Department of Statistics, The University of British Columbia, Vancouver, BC, Canada.
Guohai
G
Zhou
Department of Orthopaedics, The University of British Columbia, Vancouver, BC, Canada.
Firoz
F
Miyanji
Department of Anesthesiology, Pharmacology and Therapeutics, The University of British Columbia, Vancouver, BC, Canada.
Simon D
SD
Whyte
D000293:Adolescent; D000758:Anesthesia; D016063:Blood Loss, Surgical / Q000706:statistics & numerical data*; D001803:Blood Transfusion / Q000706:statistics & numerical data; D001831:Body Temperature; D001955:British Columbia / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D011300:Preoperative Care / Q000379:methods*; D012189:Retrospective Studies; D017694:Rewarming / Q000379:methods*; D013121:Spinal Curvatures / Q000601:surgery*; D013131:Spine / Q000601:surgery; D013530:Surgical Wound Infection / Q000453:epidemiology*
anesthesia; general/adverse effects; hot temperature/therapeutic use; hypothermia/prevention and control; intraoperative/methods; monitoring; scoliosis/surgery