J Am Acad Orthop Surg 2019 Jun 14. Epub 2019 Jun 14.
From the Department of Orthopaedic Surgery, Houston Methodist Hospital, Houston, TX.
Introduction: Perioperative hypothermia (PH) is common in patients undergoing total joint arthroplasty (TJA). A previous study at our institution identified the largest drop in core body temperature between preoperative holding and induction of anesthesia. This study evaluates the effect of preoperative warming measures on PH in TJA patients.
Methods: A retrospective review was conducted of 672 patients undergoing TJA at our institution between April 1 and October 31, 2017. Under the new normothermia protocol, patients received warmed intravenous fluids and forced-air warming gowns in the preoperative holding area. Time and temperature data for the perioperative period were collected from the electronic health record. Chi-square and paired t-tests were used to compare between total knee arthroplasty and total hip arthroplasty patients and between new and old protocols.
Results: In the new protocol, 173 of 672 (26%) patients were hypothermic at incision compared with 140 of 383 (37%) patients in the previous protocol (P < 0.05). The largest drop in core body temperature occurred between preoperative holding and induction of anesthesia. The duration of time from operating room entry to incision was less for normothermic than for hypothermic patients. The duration of hypothermia was similar between new and old protocols overall, but markedly fewer total hip arthroplasty patients remained hypothermic for the entire surgery under the new protocol.
Conclusion: Adding forced-air warming preoperatively to our warming protocol reduced the rate of PH by approximately 30%. The time from entry into the operating room to the start of surgery should be minimized because patients are vulnerable to PH during this interval.