Pediatric Preoperative Warming Protocol to Prevent Hypothermia

Abstract

Purpose: The purpose of this project was to discover the incidence of intraoperative hypothermia in pediatric patients undergoing spine surgery at Children’s Hospital of Michigan and create a preoperative warming protocol to reduce the incidence/time of intraoperative hypothermia.
Background: Intraoperative hypothermia (< 36°C) occurs in roughly two thirds of patients who undergo anesthesia. Thermoregulatory responses are impaired during a general anesthetic leading to complications such as morbid cardiac outcomes, delayed drug metabolism, increased surgical site infections, increase in surgical blood loss and the need for blood transfusions, prolonged post anesthesia recovery time and an increased length of stay. Pediatric patients are particularly at risk for hypothermia during anesthesia due to their higher body surface area to body mass ratio, increased radiant heat loss from large heads, and lower subcutaneous fat stores. Pediatric spine surgery patients are particularly vulnerable to hypothermia due to a surgical field that requires extensive exposure of body surfaces. The use of forced air warming has been utilized in the preoperative setting to warm patients prior to surgery and has been shown throughout multiple studies to reduce the incidence of intraoperative hypothermia.

Methods: A retrospective chart review was conducted on 44 pediatric spine surgery patients at Children’s Hospital of Michigan. The patient's temperature was collected in the preoperative area and every 15 minutes intraoperatively. The severity of temperature drop after induction of anesthesia as well as the duration of hypothermia was analyzed.

Results: Intraoperative hypothermia occurred in 90.1% of the cases. Patients dropped 0.8 °C immediately after induction and continued to become progressively hypothermic until 60 minutes post induction where they averaged 35.5°C. The average length of time patients remained below 36 degrees celsius was 150 minutes. A bootstrapped linear regression analysis revealed that the average length of hypothermia was increased based on the severity of post induction hypothermia.

Recommendation: After reviewing the literature and the incidence of hypothermia at Children’s Hospital of Michigan, it is our recommendation that the use of pre-operative forced air warming for at least 30 minutes prior to surgery would reduce the incidence of hypothermia in the pediatric spine surgery patient population.