The incidence and impact of hypothermia during neuraxial anaesthesia for orthopaedic surgery

Abstract

Background: Routine core temperature monitoring in patients undergoing neuraxial anaesthesia (NA) for orthopaedic surgery is not commonly performed. The incidence of hypothermia is likely high, given the low operating room temperatures recommended for these procedures.
Aim: This study aimed to determine the incidence and severity of perioperative hypothermia in patients undergoing orthopaedic surgery performed under NA.
Setting: A regional, government hospital in KwaZulu-Natal, South Africa.
Methods: We conducted a single-centre, prospective, observational study of all adults (≥ 18 years) undergoing NA for elective and emergency orthopaedic surgery in a South African regional hospital. The primary outcome was the incidence of clinically significant hypothermia occurring at any time point after NA was started until departure from theatre.
Results: We analysed results from 154 study participants. Hypothermia (core temperature < 35 °C) was found in 69 out of 154 participants (45.5%; 95% confidence interval [CI]: 37.7–53.4). Severe hypothermia (core temperature < 34 °C) was found in 22 out of 154 participants (14.3%; 95% CI: 9.6–20.8). Hypothermia was associated with lower ambient temperature, increasing age and increased blood loss.
Conclusion: Hypothermia was present in almost half of participants undergoing orthopaedic surgery under NA, and one in seven experienced severe hypothermia. Temperature monitoring should be considered essential in all patients undergoing NA for orthopaedic procedures although core temperature monitoring may not always be available or practical. Preventing unnecessarily low ambient theatre temperatures should be considered as a strategy to prevent hypothermia. Avoiding prolonged patient exposure following insertion of NA should also be prioritised.
Contribution: Further research into effective prevention of hypothermia and the potential clinical impact of perioperative hypothermia in orthopaedic procedures under NA is warranted.