Show Summary Details
Page of

Pathophysiology and management of hypothermia 

Pathophysiology and management of hypothermia
Chapter:
Pathophysiology and management of hypothermia
Author(s):

Colin Ferguson

DOI:
10.1093/med/9780199600830.003.0354
Page of

PRINTED FROM OXFORD MEDICINE ONLINE (www.oxfordmedicine.com). © Oxford University Press, 2021. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Medicine Online for personal use (for details see Privacy Policy and Legal Notice).

date: 18 October 2021

Accidental hypothermia is defined as a core temperature of <35°C and is uncommon. It may present in any age group at any time of the year. Hypothermia may be primary, where the cold injury is the major pathology, or secondary where patients develop hypothermia incidental to another illness. Since the severely cold patient may be in cardiac arrest, areflexic, and in coma, decision making regarding treatment, its initiation, and continuation, may be difficult. Hypothermia is classified into mild (33–35°C), moderate (28–33°C) and severe (<28°C), but these are not distinct clinical syndromes. A more recent classification into stages has emerged from alpine medicine along with a treatment algorithm based on it. Many pathophysiogical changes are due to reduced enzyme action. Clinical features include changes in higher cerebral functions with bizarre behaviour progressing to coma. In the circulation initial tachycardia and hypertension (‘cold stress’) are replaced, as the patient cools, with worsening hypotension and bradycardia and, eventually, ventricular fibrillation and asystole. Rewarming methods are classified as passive or active and the latter subdivided into external, core, and extracorporeal. Active warming should be considered for patients with a temperature of 32°C or lower. Peritoneal lavage has the advantage of warming the liver directly and also the heart through the diaphragm. Cardiopulmonary bypass is the extracorporeal method with most experience, but the advent of extracorporeal membrane oxygenation has the advantage of portability.

Access to the complete content on Oxford Medicine Online requires a subscription or purchase. Public users are able to search the site and view the abstracts for each book and chapter without a subscription.

Please subscribe or login to access full text content.

If you have purchased a print title that contains an access token, please see the token for information about how to register your code.

For questions on access or troubleshooting, please check our FAQs, and if you can't find the answer there, please contact us.