Body temperature change and outcomes in patients undergoing long-distance air medical transport

Mikio Nakajima; Shotaro Aso; Hideo Yasunaga; Masamitsu Shirokawa; Tomotsugu Nakano; Yasuhiko Miyakuni; Hideaki Goto; Yoshihiro Yamaguchi

doi:10.1016/j.ajem.2018.04.064

Body temperature change and outcomes in patients undergoing long-distance air medical transport

Am J Emerg Med. 2019 Jan;37(1):89-93. doi: 10.1016/j.ajem.2018.04.064. Epub 2018 Apr 30.

Authors

Mikio Nakajima¹, Shotaro Aso², Hideo Yasunaga³, Masamitsu Shirokawa⁴, Tomotsugu Nakano⁴, Yasuhiko Miyakuni⁵, Hideaki Goto⁶, Yoshihiro Yamaguchi⁷

Affiliations

¹ Emergency and Critical Care Center, Tokyo Metropolitan Hiroo Hospital, 2-34-10, Ebisu, Shibuya-ku, Tokyo 150-0013, Japan; Department of Trauma and Critical Care Medicine, School of Medicine, Kyorin University, 6-20-2, Shinkawa, Mitaka-shi, Tokyo 181-8611, Japan. Electronic address: mikioh@ks.kyorin-u.ac.jp.
² Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. Electronic address: asou-sin@umin.ac.jp.
³ Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. Electronic address: yasunaga-tky@umin.ac.jp.
⁴ Emergency and Critical Care Center, Tokyo Metropolitan Hiroo Hospital, 2-34-10, Ebisu, Shibuya-ku, Tokyo 150-0013, Japan.
⁵ Department of Trauma and Critical Care Medicine, School of Medicine, Kyorin University, 6-20-2, Shinkawa, Mitaka-shi, Tokyo 181-8611, Japan.
⁶ Emergency and Critical Care Center, Tokyo Metropolitan Hiroo Hospital, 2-34-10, Ebisu, Shibuya-ku, Tokyo 150-0013, Japan. Electronic address: hideaki_gotou@tmhp.jp.
⁷ Department of Trauma and Critical Care Medicine, School of Medicine, Kyorin University, 6-20-2, Shinkawa, Mitaka-shi, Tokyo 181-8611, Japan. Electronic address: gaius@ks.kyorin-u.ac.jp.

PMID: 29730095
DOI: 10.1016/j.ajem.2018.04.064

Abstract

Background: Short-distance air medical transport for adult emergency patients does not significantly affect patients' body temperature and outcomes. This study aimed to examine the influence of long-distance air medical transport on patients' body temperatures and the relationship between body temperature change and mortality.

Methods: We retrospectively enrolled consecutive patients transferred via helicopter or plane from isolated islands to an emergency medical center in Tokyo, Japan between April 2010 and December 2016. Patients' average body temperature was compared before and after air transport using a paired t-test, and corrections between body temperature change and flight duration were calculated using Pearson's correlation coefficient. Multivariable logistic regression models were then used to examine the association between body temperature change and in-hospital mortality.

Results: Of 1253 patients, the median age was 72 years (interquartile range, 60-82 years) and median flight duration was 71 min (interquartile range, 54-93 min). In-hospital mortality was 8.5%, and average body temperature was significantly different before and after air transport (36.7 °C versus 36.3 °C; difference: -0.36 °C; 95% confidence interval, -0.30 to -0.42; p < 0.001). There was no correlation between body temperature change and flight duration (r = 0.025, p = 0.371). In-hospital death was significantly associated with (i) hyperthermia (>38.0 °C) or normothermia (36.0-37.9 °C) before air transport and hypothermia after air transport (odds ratio, 2.08; 95% confidence interval, 1.20-3.63; p = 0.009), and (ii) winter season (odds ratio, 2.15; 95% confidence interval, 1.08-4.27; p = 0.030).

Conclusion: Physicians should consider body temperature change during long-distance air transport in patients with not only hypothermia but also normothermia or hyperthermia before air transport, especially in winter.

Keywords: Aeromedical; Air ambulances; Air transport; Body temperature; Helicopter; Hypothermia.

MeSH terms

Aged
Aged, 80 and over
Air Ambulances*
Body Temperature / physiology*
Body Temperature Regulation
Critical Illness / therapy*
Emergency Medical Services
Female
Health Services Research
Humans
Hypothermia / therapy*
Injury Severity Score
Male
Middle Aged
Prognosis
Retrospective Studies