eMedicine Specialties > Emergency Medicine > Environmental

Hypothermia: Differential Diagnoses & Workup

Author: Jamie Alison Edelstein, MD, Staff Physician, Department of Emergency Medicine, State University of New York, Kings County Hospital Center
Coauthor(s): James Li, MD, Former Assistant Professor, Division of Emergency Medicine, Harvard Medical School; Board of Directors, Remote Medicine; Mark A Silverberg, MD, FACEP, MMB, Assistant Professor, Assistant Residency Director, Department of Emergency Medicine, State University of New York Downstate College of Medicine; Consulting Staff, Department of Emergency Medicine, Staten Island University Hospital, Kings County Hospital, University Hospital, State University of New York Downstate at Brooklyn; Wyatt Decker, MD, Chair and Program Director, Department of Emergency Medicine, Mayo Clinic
Contributor Information and Disclosures

Updated: Oct 29, 2009

Differential Diagnoses

Stroke, Hemorrhagic
Toxicity, Ethylene Glycol
Stroke, Ischemic
Toxicity, Gamma-Hydroxybutyrate
Therapeutic Hypothermia
Toxicity, Narcotics
Toxicity, Alcohols
Toxicity, Sedative-Hypnotics
Toxicity, Barbiturate
Ventricular Fibrillation
Toxicity, Benzodiazepine
Ventricular Tachycardia
Toxicity, Carbon Monoxide

Workup

Laboratory Studies

  • Arterial blood gas determination
    • Blood gas analyzers warm blood to 37°C.
    • Because gasses are less soluble in hypothermic plasma, arterial blood gas (ABG) level may show higher oxygen and carbon dioxide levels and a lower pH than a patient's actual values as the blood is warmed in the ABG machinery.
    • The best approach is to expect uncorrected ABG values compared with the normal values at 37°C.
    • An uncorrected pH at 7.4 and pCO2 at 40 mm Hg reflect acid-base balance.
  • Many hypothermic patients are volume contracted because of cold diuresis. As a result, hematocrit level may be deceptively high. Hematocrit levels may increase 2% for each 1°C drop in core temperature.
  • Hypothermia may present with wide fluctuations in electrolytes, and no clear trend or predictability exists as to when a patient's electrolytes will be abnormal or how large swings may be.
    • Plasma potassium levels can be useful in evaluating prognosis. A level of 10 mmol/L or greater is associated with a very low likelihood of recovery.
    • Classic ECG changes of hyperkalemia may be absent or diminished.
    • Chronic hypothermia occasionally can lead to hypokalemia.
  • Acute hypothermia can result in hyperglycemia, while chronic hypothermia or secondary hypothermia may present with low blood glucose level.
  • The body's coagulation mechanism is often disrupted in moderate or severe hypothermia, and a disseminated intervascular coagulation–type syndrome can be present.
    • Coagulopathy has several causes. The primary issue is disruption of enzymatic reactions of the clotting cascade caused by protein denaturization at decreased temperature.
    • Because the kinetic tests of coagulation are performed at 37°C in the laboratory, a clinically evident coagulopathy may not be reflected by deceptively normal laboratory values.

Imaging Studies

  • A chest radiograph is indicated in patients with hypoxia. Aspiration pneumonia and pulmonary edema are common findings.
  • Patients with trauma or altered mental status of indeterminate cause may need a noncontrast head CT scan and further imaging for a standard trauma evaluation.

Other Tests

  • The ECG may show prolonged PR, QRS, and QT intervals, and atrial or ventricular arrhythmias. The length and height of the respective QT-interval prolongation and characteristic J (Osborne) waves are often proportional to the degree of hypothermia.

More on Hypothermia

Overview: Hypothermia
Differential Diagnoses & Workup: Hypothermia
Treatment & Medication: Hypothermia
Follow-up: Hypothermia
Multimedia: Hypothermia
References
[ CLOSE WINDOW ]

References

  1. Polderman KH. Mechanisms of action, physiological effects, and complications of hypothermia. Crit Care Med. Jul 2009;37(7 Suppl):S186-202. [Medline].

  2. Long WB 3rd, Edlich RF, Winters KL, Britt LD. Cold injuries. J Long Term Eff Med Implants. 2005;15(1):67-78. [Medline].

  3. Sessler DI. Thermoregulatory defense mechanisms. Crit Care Med. Jul 2009;37(7 Suppl):S203-10. [Medline].

  4. McCullough L, Arora S. Diagnosis and treatment of hypothermia. Am Fam Physician. Dec 15 2004;70(12):2325-32. [Medline].

  5. Laniewicz M, Lyn-Kew K, Silbergleit R. Rapid endovascular warming for profound hypothermia. Ann Emerg Med. Feb 2008;51(2):160-3. [Medline].

  6. Abella BS, Rhee JW, Huang KN, Vanden Hoek TL, Becker LB. Induced hypothermia is underused after resuscitation from cardiac arrest: a current practice survey. Resuscitation. Feb 2005;64(2):181-6. [Medline].

  7. Alam HB, Rhee P, Honma K, et al. Does the rate of rewarming from profound hypothermic arrest influence the outcome in a swine model of lethal hemorrhage?. J Trauma. Jan 2006;60(1):134-46. [Medline].

  8. Bernard SA, Gray TW, Buist MD, et al. Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia. N Engl J Med. Feb 21 2002;346(8):557-63. [Medline]. [Full Text].

  9. Biancolini CA, Del Bosco CG, Jorge MA, Poderoso JJ, Capdevila AA. Active core rewarming in neurologic, hypothermic patients: effects on oxygen-related variables. Crit Care Med. Aug 1993;21(8):1164-8. [Medline].

  10. Biem J, Koehncke N, Classen D, Dosman J. Out of the cold: management of hypothermia and frostbite. CMAJ. Feb 4 2003;168(3):305-11. [Medline].

  11. Britt LD, Dascombe WH, Rodriguez A. New horizons in management of hypothermia and frostbite injury. Surg Clin North Am. Apr 1991;71(2):345-70. [Medline].

  12. Brunette DD, Sterner S, Robinson EP, Ruiz E. Comparison of gastric lavage and thoracic cavity lavage in the treatment of severe hypothermia in dogs. Ann Emerg Med. Nov 1987;16(11):1222-7. [Medline].

  13. Buckley JJ, Bosch OK, Bacaner MB. Prevention of ventricular fibrillation during hypothermia with bretylium tosylate. Anesth Analg. Jul-Aug 1971;50(4):587-93. [Medline].

  14. Casas F, Alam H, Reeves A, Chen Z, Smith WA. A portable cardiopulmonary bypass/extracorporeal membrane oxygenation system for the induction and reversal of profound hypothermia: feasibility study in a Swine model of lethal injuries. Artif Organs. Jul 2005;29(7):557-63. [Medline].

  15. Centers for Disease Control and Prevention (CDC). Hypothermia-related deaths--United States, 2003-2004. MMWR Morb Mortal Wkly Rep. Feb 25 2005;54(7):173-5. [Medline].

  16. Danzl DF, Pozos RS. Accidental hypothermia. N Engl J Med. Dec 29 1994;331(26):1756-60. [Medline].

  17. Danzl DF, Pozos RS, Auerbach PS, et al. Multicenter hypothermia survey. Ann Emerg Med. Sep 1987;16(9):1042-55. [Medline].

  18. Danzl DF, Pozos RS, Hamlet MP. Accidental hypothermia. In: Wilderness Medicine. 51-103.

  19. [Guideline] ECC Committee, Subcommittees and Task Forces of the American Heart Association. 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. Dec 13 2005;112(24 Suppl):IV1-203. [Medline].

  20. Elbaz G, Etzion O, Delgado J, Porath A, Talmor D, Novack V. Hypothermia in a desert climate: severity score and mortality prediction. Am J Emerg Med. Jul 2008;26(6):683-8. [Medline].

  21. Fildes J, Sheaff C, Barrett J. Very hot intravenous fluid in the treatment of hypothermia. J Trauma. Nov 1993;35(5):683-6; discussion 686-7. [Medline].

  22. Gentilello LM, Cobean RA, Offner PJ, Soderberg RW, Jurkovich GJ. Continuous arteriovenous rewarming: rapid reversal of hypothermia in critically ill patients. J Trauma. Mar 1992;32(3):316-25; discussion 325-7. [Medline].

  23. Hall KN, Syverud SA. Closed thoracic cavity lavage in the treatment of severe hypothermia in human beings. Ann Emerg Med. Feb 1990;19(2):204-6. [Medline].

  24. Headdon WG, Wilson PM, Dalton HR. The management of accidental hypothermia. BMJ. Jun 10 2009;338:b2085. [Medline].

  25. Jurkovich GJ. Environmental cold-induced injury. Surg Clin North Am. Feb 2007;87(1):247-67, viii. [Medline].

  26. Kanzenbach TL, Dexter WW. Cold injuries. Protecting your patients from the dangers of hypothermia and frostbite. Postgrad Med. Jan 1999;105(1):72-8. [Medline].

  27. Keatinge WR. Hypothermia: dead or alive?. BMJ. Jan 5 1991;302(6767):3-4. [Medline].

  28. Ko CS, Alex J, Jeffries S, Parmar JM. Dead? Or just cold: profoundly hypothermic patient with no signs of life. Emerg Med J. Sep 2002;19(5):478-9. [Medline]. [Full Text].

  29. Launay JC, Savourey G. Cold adaptations. Ind Health. Jul 2009;47(3):221-7. [Medline].

  30. Mechem CC. Accidental Hypothermia. www.uptodate.com.

  31. Murphy K, Nowak RM, Tomlanovich MC. Use of bretylium tosylate as prophylaxis and treatment in hypothermic ventricular fibrillation in the canine model. Ann Emerg Med. Oct 1986;15(10):1160-6. [Medline].

  32. Plaisier BR. Thoracic lavage in accidental hypothermia with cardiac arrest--report of a case and review of the literature. Resuscitation. Jul 2005;66(1):99-104. [Medline].

  33. Romet TT, Hoskin RW. Temperature and metabolic responses to inhalation and bath rewarming protocols. Aviat Space Environ Med. Jul 1988;59(7):630-4. [Medline].

  34. Savard GK, Cooper KE, Veale WL, Malkinson TJ. Peripheral blood flow during rewarming from mild hypothermia in humans. J Appl Physiol. Jan 1985;58(1):4-13. [Medline].

  35. Schewe JC, Heister U, Fischer M, Hoeft A. [Accidental urban hypothermia. Severe hypothermia of 20.7 degrees C]. Anaesthesist. Oct 2005;54(10):1005-11. [Medline].

  36. Spencer SM, Roeseler J, Verschuren F, Reynaert M, Thys F. Metabolism study in an 88-year-old woman with severe hypothermia during rewarming procedures. Am J Emerg Med. Oct 2007;25(8):986.e1-3. [Medline].

  37. Ulrich AS, Rathlev NK. Hypothermia and localized cold injuries. Emerg Med Clin North Am. May 2004;22(2):281-98. [Medline].

  38. Vachiery JL, Reuse C, Blecic S, Contempre B, Vincent JL. Bretylium tosylate versus lidocaine in experimental cardiac arrest. Am J Emerg Med. Nov 1990;8(6):492-5. [Medline].

  39. Walpoth BH, Walpoth-Aslan BN, Mattle HP, et al. Outcome of survivors of accidental deep hypothermia and circulatory arrest treated with extracorporeal blood warming. N Engl J Med. Nov 20 1997;337(21):1500-5. [Medline].

  40. Webb P. Afterdrop of body temperature during rewarming: an alternative explanation. J Appl Physiol. Feb 1986;60(2):385-90. [Medline].

  41. Wilkerson JA. Hypothermia, Frostbite, and other Cold Injuries. 1986.

  42. Zachary L, Kucan JO, Robson MC, Frank DH. Accidental hypothermia treated with rapid rewarming by immersion. Ann Plast Surg. Sep 1982;9(3):238-41. [Medline].

[ CLOSE WINDOW ]

Further Reading

[ CLOSE WINDOW ]

Keywords

hypothermia, environmental exposure, accidental hypothermia, intentional hypothermia, primary hypothermia, secondary hypothermia, atrial arrhythmia, ventricular arrhythmia, ventricular fibrillation, core temperature drop, decreased heat production, increased heat loss, impaired thermoregulation, mild hypothermia, moderate hypothermia, severe hypothermia

[ CLOSE WINDOW ]

Contributor Information and Disclosures

Author

Jamie Alison Edelstein, MD, Staff Physician, Department of Emergency Medicine, State University of New York, Kings County Hospital Center
Disclosure: Nothing to disclose.

Coauthor(s)

James Li, MD, Former Assistant Professor, Division of Emergency Medicine, Harvard Medical School; Board of Directors, Remote Medicine
Disclosure: Nothing to disclose.

Mark A Silverberg, MD, FACEP, MMB, Assistant Professor, Assistant Residency Director, Department of Emergency Medicine, State University of New York Downstate College of Medicine; Consulting Staff, Department of Emergency Medicine, Staten Island University Hospital, Kings County Hospital, University Hospital, State University of New York Downstate at Brooklyn
Mark A Silverberg, MD, FACEP, MMB is a member of the following medical societies: American College of Emergency Physicians, American Medical Association, Council of Emergency Medicine Residency Directors, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Wyatt Decker, MD, Chair and Program Director, Department of Emergency Medicine, Mayo Clinic
Wyatt Decker, MD is a member of the following medical societies: American College of Emergency Physicians
Disclosure: Nothing to disclose.

Medical Editor

Dan Danzl, MD, Chair, Department of Emergency Medicine, Professor, University of Louisville Hospital
Dan Danzl, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, Kentucky Medical Association, Society for Academic Emergency Medicine, and Wilderness Medical Society
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

James Steven Walker, DO, MS, Clinical Professor of Surgery, Department of Surgery, University of Oklahoma Health Sciences Center
James Steven Walker, DO, MS is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American College of Osteopathic Emergency Physicians, and American Osteopathic Association
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Jonathan Adler, MD, Attending Physician, Department of Emergency Medicine, Massachusetts General Hospital; Division of Emergency Medicine, Harvard Medical School
Jonathan Adler, MD is a member of the following medical societies: American Academy of Emergency Medicine and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

 
 
HONcode

We subscribe to the
HONcode principles of the
Health On the Net Foundation

All material on this website is protected by copyright, Copyright© 1994- by Medscape.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.