hypothermia
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Introduction
A core temperature < 35 degrees C (95 degrees F).
Etiology
- environmental exposure
- drugs
- metabolic (endocrine) disorders
- hypothalamic dysfunction
- spinal cord transection (T1 of above)
- skin disorders
- general debilitation
- episodic spontaneous hypothermia with hyperhidrosis
- sepsis
- uremia
Epidemiology
- patients with impaired thermoregulation or perception of cold are at greatest risk
- elderly
- intoxicated persons[1]
Clinical manifestations
- mild hypothermia (32-35 C or 89.6-95 F)
- shivering
- delirium, alert, poor judgement
- pulse may be normal or increased
- blood pressure may be normal or increased[1]
- below 28-32 C (82.4-89.6 F)
- shivering ceases
- metabolism slows
- multiple organ system dysfunction occurs
- pulse, blood pressure & respirations decline
- consciousness progressively declines
- below 28 C (82.4 F)*
- comatose
- pupils are fixed & dilated
- reflexes are absent
- hypotension
- pulse & respirations are barely detectable or absent
* case report of 76 year old demented woman with core temperature of 26 C (78.8 F)[5]
Laboratory
- arterial blood gas (ABG) - respiratory acidosis
- complete blood count (CBC)
- elevated hematocrit from hemoconcentration
- leukopenia
- thrombocytopenia
Diagnostic procedures
- atrial fibrillation
- Osborne J wave* < 29 C[5] (image)
* magnitude of the J waves may be associated with degree of hypothermia. but are not specific for hypothermia
Management
- responsive patients
- warming with blankets
- warm, humidified air
- warm intravenous fluids
- shivering patients usually recover spontaneously if removed from cold environment & kept dry[1]
- unresponsive patients (< 32 degrees C)
- during emergency care, aim for 32-36 degrees C & maintain temperature for at least 24 hours[3]
- active core warming with gastric, colonic or peritoneal lavage
- hemodialysis can be used for warming mostly for in conjunction with severe acid-base disturbances, not for core temperature < 28 C)[3]
- cardiopulmonary bypass[1]
- patients should not be pronounced dead until they have been warmed to a core temperature of > 32 C (> 89.6 F) presumably for at least 24 hours[3]
More general terms
More specific terms
Additional terms
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Medical Knowledge Self Assessment Program (MKSAP) 11, 16, 17,18, 19. American College of Physicians, Philadelphia 1998, 2012, 2015, 2018, 2022
- ↑ Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 98
- ↑ 3.0 3.1 3.2 3.3 Physician's First Watch, Oct 20, 2015 David G. Fairchild, MD, MPH, Editor-in-Chief Massachusetts Medical Society http://www.jwatch.org
2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. (in 15 parts, see Table of Contents) Circulation November 3, 2015, Volume 132, Issue 18 suppl 2 http://circ.ahajournals.org/content/132/18_suppl_2.toc - ↑ Brown DJ, Brugger H, Boyd J, Paal P Accidental hypothermia. N Engl J Med. 2012 Nov 15;367(20):1930-8. Review PMID: https://www.ncbi.nlm.nih.gov/pubmed/23150960
- ↑ 5.0 5.1 5.2 Kampouri E, Vaucher J. Electrocardiographic Changes in Hypothermia N Engl J Med 2018; 378:460. Feb 1, 2018 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/29385369 <Internet> http://www.nejm.org/doi/full/10.1056/NEJMicm1704534
- ↑ Hilmo J, Naesheim T, Gilbert M. "Nobody is dead until warm and dead": prolonged resuscitation is warranted in arrested hypothermic victims also in remote areas- a retrospective study from northern Norway. Resuscitation. 2014 Sep;85(9):1204-11. PMID: https://www.ncbi.nlm.nih.gov/pubmed/24882104 Free Article