A 79-year-old man is found poorly responsive in his apartment by a neighbor in the middle of July. The apartment is not air conditioned and the last few days have been extremely hot. The patient's neighbors state that he lives alone and appeared fully functional in their interactions with him. No additional medical history is available.
On physical examination, he appears obtunded and responds slowly to commands. His temperature is 42.2° C (108° F), blood pressure is 90/60 mm Hg, pulse is 104/min, and respirations are 16/min. The patient's pulse oximetry shows 96% on room air. Mucous membranes are dry. His neck is supple, and jugular veins are flat in the supine position. Cardiopulmonary examination is within normal limits. There are no skin rashes. Deep tendon reflexes are 2+ and symmetrical. There is no muscular rigidity.
An electrocardiogram demonstrates sinus rhythm with nonspecific ST-segment changes. A chest film shows no significant abnormalities. Laboratory workup is pending.
In addition to volume resuscitation, which of the following is the best initial therapy for this patient?

Question

A 79-year-old man is found poorly responsive in his apartment by a neighbor in the middle of July.  The apartment is not air conditioned and the last few days have been extremely hot.  The patient's neighbors state that he lives alone and appeared fully functional in their interactions with him.  No additional medical history is available.
On physical examination, he appears obtunded and responds slowly to commands.  His temperature is 42.2° C (108° F), blood pressure is 90/60 mm Hg, pulse is 104/min, and respirations are 16/min.  The patient's pulse oximetry shows 96% on room air.  Mucous membranes are dry.  His neck is supple, and jugular veins are flat in the supine position.  Cardiopulmonary examination is within normal limits.  There are no skin rashes.  Deep tendon reflexes are 2+ and symmetrical.  There is no muscular rigidity.
An electrocardiogram demonstrates sinus rhythm with nonspecific ST-segment changes.  A chest film shows no significant abnormalities.  Laboratory workup is pending.
In addition to volume resuscitation, which of the following is the best initial therapy for this patient?

Quizplus · Accepted Answer

This patient's presentation is consistent with classic (nonexertional) heat stroke. Nonexertional heat stroke is more common in the elderly and those with chronic medical conditions. Exertional heat stroke is more common in young healthy athletes exercising heavily in high ambient temperature and humidity. Heat stroke mortality is reported as 20%-60%. Hyperthermia management includes supportive measures (eg, airway protection, circulatory support), rapid evaporative cooling, cold IV normal saline boluses for hypotension or volume depletion, cooled oxygen and blankets, and temperature monitoring via rectal or esophageal probes. Evaporated cooling is safe, noninvasive, effective, and does not interfere with other treatment and monitoring. The technique involves spraying mists of water with fans blowing air over moist skin. Ice water immersion is also quick and effective in reducing the body temperature. However, it interferes with monitoring and is associated with increased mortality in elderly patients with classic (nonexertional) heat stroke. Younger patients with exertional heat stroke can better tolerate this technique (Choice E). (Choice A) Alcohol sponge baths should be avoided because large amounts of alcohol may be absorbed through dilated cutaneous blood vessels and lead to systemic toxicity. (Choice B) Antipyretics (eg, acetaminophen, aspirin) are not helpful in heat stroke as the mechanism is not regulated by the hypothalamus. Aspirin may even exacerbate complications such as renal failure or disseminated intravascular coagulation. (Choice C) Dantrolene is effective for treating hyperthermia associated with neuroleptic malignant syndrome but is ineffective in other hyperthermic disorders. The absence of muscular rigidity makes neuroleptic malignant syndrome unlikely. Educational objective: Management of classic (nonexertional) heat stroke includes cooling methods (eg, evaporative cooling), circulatory support (with intravenous fluid boluses), airway management, and treatment of complications. Antipyretics and dantrolene are not useful in the management of heat stroke. __________ References: Hot on the inside. (http://www.ncbi.nlm.nih.gov/pubmed/12889421) Successful treatment of severe heatstroke with therapeutic hypothermia by a noninvasive external cooling system. (http://www.ncbi.nlm.nih.gov/pubmed/21982153)

A 79-Year-Old Man Is Found Poorly Responsive in His Apartment