Accidental cold-related injury leading to hospitalization in northern Sweden: an eight-year retrospective analysis.
BACKGROUND
Cold injuries are rare but important causes of hospitalization. We aimed to identify the magnitude of cold injury hospitalization, and assess causes, associated factors and treatment routines in a subarctic region.


METHODS
In this retrospective analysis of hospital records from the 4 northernmost counties in Sweden, cases from 2000-2007 were identified from the hospital registry by diagnosis codes for accidental hypothermia, frostbite, and cold-water drowning. Results were analyzed for pre-hospital site events, clinical events in-hospital, and complications observed with mild (temperature 34.9 - 32°C), moderate (31.9 - 28°C) and severe (<28°C), hypothermia as well as for frostbite and cold-water drowning.


RESULTS
From the 362 cases, average annual incidences for hypothermia, frostbite, and cold-water drowning were estimated to be 3.4/100,000, 1.5/100,000, and 0.8/100,000 inhabitants, respectively. Annual frequencies for hypothermia hospitalizations increased by approximately 3 cases/year during the study period. Twenty percent of the hypothermia cases were mild, 40% moderate, and 24% severe. For 12%, the lowest documented core temperature was 35°C or higher, for 4% there was no temperature documented. Body core temperature was seldom measured in pre-hospital locations. Of 362 cold injury admissions, 17 (5%) died in hospital related to their injuries. Associated co-factors and co-morbidities included ethanol consumption, dementia, and psychiatric diagnosis.


CONCLUSIONS
The incidence of accidental hypothermia seems to be increasing in this studied sub-arctic region. Likely associated factors are recognized (ethanol intake, dementia, and psychiatric diagnosis).
Department of Surgical and Perioperative Sciences, Anesthesia and Intensive Care Medicine, Faculty of Medicine, Umeå University, S-901 85 Umeå, Sweden. helge.brandstrom@vll.se.
Helge
H
Brändström
Göran
G
Johansson
Gordon G
GG
Giesbrecht
Karl-Axel
KA
Ängquist
Michael F
MF
Haney
D003080:Cold Temperature / Q000009:adverse effects*; D005500:Follow-Up Studies; D006753:Hospital Records; D006760:Hospitalization / Q000639:trends*; D006801:Humans; D007035:Hypothermia / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D015994:Incidence; D012189:Retrospective Studies; D017694:Rewarming / Q000379:methods; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors