Intraoperative Hypothermia is Common, but not Associated With Blood Loss or Transfusion in Pediatric Posterior Spinal Fusion.

Abstract

Intraoperative hypothermia may be associated with increased blood loss due to the effects of temperature on clotting but this has not been evaluated in the setting of pediatric posterior spinal fusion (PSF). The purpose of this study was to determine if a correlation exists between intraoperative hypothermia and estimated blood loss (EBL) or transfusion requirements in pediatric patients undergoing PSF. A retrospective review of consecutive patients undergoing PSF for scoliosis at a single institution between 6/2004 and 3/2012 was performed. Exclusion criteria were fewer than 10 levels fused, anterior spinal fusion, and patients below 9 years old at time of surgery. Temperature was measured every 15 seconds using esophageal temperature probe. Input variable of hypothermia was analyzed as a binary variable Tmin ≤35°C at any point during anesthesia and as integrated temperature area under the curve (TAUC). A total of 510 with an average age of 14.6 years (range, 9.0 to 24.3 y) met inclusion criteria. Totally, 56% (287/510) had idiopathic scoliosis (IS) and 44% (223/510) were non-IS. Hypothermia (Tmin≤35°C) was experienced by 45% (230/510) of all patients [48% (137/287) of IS; 42% (93/223) of non-IS]. A total of 63% (323/510) of patients were transfused with packed red blood cells (PRBC) [49% (141/287) of IS patients; 82% (182/223) of non-IS patients]. There was no correlation between Tmin≤35°C and transfusion of PRBC in all included patients (P=0.49); (IS patients P=0.45, non-IS patients P=0.61). There was no significant difference in EBL between patients who experienced hypothermia and those who did not (P=0.33; IS patients P=0.21, non-IS patients P=0.87). There was no significant correlation between TAUC and transfusion of PRBC for all patients (P=0.35), IS patients (P=0.26) and non-IS patients (P=0.54) or between TAUC and EBL (P=0.80); (IS patients P=0.57. non-IS patients P=0.62). There was no significant correlation between intraoperative hypothermia and EBL or transfusion of PRBC in pediatric patients undergoing PSF. Level III.