Accidental cold-related injury leading to hospitalization in northern Sweden: an eight-year retrospective analysis
Helge Brndstrm
0
3
Gran Johansson
0
3
Gordon G Giesbrecht
2
Karl-Axel ngquist
1
Michael F Haney
0
3
0
Department of Surgical and Perioperative Sciences, Anesthesia and Intensive Care Medicine, Faculty of Medicine, Umea University
,
S-901 85 Umea
,
Sweden
1
Emergency and Disaster Medicine Centre, Umea University
,
S-901 85 Umea
,
Sweden
2
Kinesiology and Recreation Management, and Anesthesia, University of Manitoba
,
Winnipeg
,
Canada
3
Department of Surgical and Perioperative Sciences, Anesthesia and Intensive Care Medicine, Faculty of Medicine, Umea University
,
S-901 85 Umea
,
Sweden
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 - 32C), moderate (31.9 - 28C) and severe (<28C), 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 35C 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).
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Background
Accidental cold injuries, including hypothermia, frostbite
and cold-water drowning, are important causes of injury
and hospitalization in subarctic regions [1-5]. Interest in
these types of accidental injuries has increased after
several cold-weather mass casualty events, [6,7] where
immersion and submersion in cold water has led to
lifethreatening hypothermia and cold-water drowning.
Incidences and outcomes of cold injury have been reported
for some regions [8] or nations [9] and in military
populations [10,11]. Accidental cold-related injury is a potentially
life-threatening condition that can lead to significant
morbidity and life-long effects. Populations in cold climate
regions, without proper safeguards and preparation when
outdoors, are always at risk for cold injury. Based on
previously published material, it is recognized that the
occurrence of cold-related injury is often multifactorial [12-16].
Factors contributing to fatal hypothermia have been
recently described [17]. It is not known if cold injury
hospitalization and in-hospital survival is increasing over
time, since presumably there is steady progress in
prevention and treatment.
The aim of this study was to identify the incidence of
cold-related patient injuries, and describe the
rescueactivities, pre- and in-hospital treatment, and injury
panorama in Northern Sweden during an 8-year study
period from 2000 to 2007. Additionally, we wanted to
estimate the association between cold-related injuries
and ethanol/drug use, psychiatric illness or dementia, and
accidents.
Methods
Identification of the cohort
This retrospective study was conducted with approval
from the Regional Ethical Review Board in Ume, Sweden.
Data was collected from patient records for those
admitted to the 12 hospitals in northern Sweden, population
approximately 900 000 (the northern four County Council
health care districts) for eight years, from 2000 to 2007.
Subjects were identified in the hospitals patient
administrative system using the International Classification of
Diseases, version 10 (ICD-10) [18]. The codes for
hypothermia (T68), frostbite (T33.0-T35.7) and drowning
(T75.1) were used as search criteria. We identified
coldwater drowning based on drowning site water
temperature < 20C, [19,20] from municipality-reported lake/river
temperatures at the time of the accident.
Data collection from hospital records
The diagnosis of hypothermia was based on the history
and setting, clinical signs and symptoms as interpreted
by the hospital physician in charge of the patient,
together with measurement of core temperature. The
diagnosis of frostbite was based on the history or clinical
setting, together wit (...truncated)