A 45-year-old homeless man is found unresponsive on the street and brought to the emergency department. The ambient temperature outside is -6.7 C (20 F). He has no evidence of trauma and no other medical history is available.
The patient's blood pressure is 88/60 mm Hg, pulse is 60/min, and respirations are 22/min. Rectal temperature is 29 C (84.2 F). He is cold to the touch, responds only to deep pain, and is not shivering. Cardiopulmonary and abdominal examinations are within normal limits.
ECG shows atrial fibrillation with a slow ventricular response. The patient is intubated in the emergency department and blood work, including blood cultures, is sent. A chest x-ray is ordered.
In addition to passive and active external rewarming and general supportive care, which of the following is the most appropriate therapy for the patient at this time?

Question

A 45-year-old homeless man is found unresponsive on the street and brought to the emergency department.  The ambient temperature outside is -6.7 C (20 F).  He has no evidence of trauma and no other medical history is available.
The patient's blood pressure is 88/60 mm Hg, pulse is 60/min, and respirations are 22/min.  Rectal temperature is 29 C (84.2 F).  He is cold to the touch, responds only to deep pain, and is not shivering.  Cardiopulmonary and abdominal examinations are within normal limits.
ECG shows atrial fibrillation with a slow ventricular response.  The patient is intubated in the emergency department and blood work, including blood cultures, is sent.  A chest x-ray is ordered.
In addition to passive and active external rewarming and general supportive care, which of the following is the most appropriate therapy for the patient at this time?

Quizplus · Accepted Answer

11ec193a_969f_b88c_853d_b972c9d96180_MD0002_00 This patient's abnormal mental state, temperature, and hypotension are consistent with moderate hypothermia from cold exposure. Patients may have varying symptoms depending on the severity of hypothermia. Hypotension is common and is usually due to renal salt/water losses from cold-induced diuresis; initial rewarming may cause systemic vasodilation and worsen the hypotension. The recommended method of rewarming depends on the severity of the hypothermia. Mild hypothermia is treated with passive rewarming (eg, covering with blankets, removing wet clothing). Moderate hypothermia in a hemodynamically stable patient may also improve with active external rewarming (eg, heating pads, warm baths). This patient's moderate hypothermia with significant hypotension should be treated with large volumes of warmed (42 C [107.6 F]) intravenous crystalloid fluids. Core temperature may initially drop slightly with treatment due to return of blood from cold extremities. (Choices A and D) Although severe infection and adrenal insufficiency can cause hypothermia, this patient should be resuscitated with warm saline before evaluation for other etiologies. (Choice B) Active internal rewarming is indicated for severe hypothermia or for moderate hypothermia that does not respond to initial measures. Interventions may include warmed pleural or peritoneal irrigation, cardiopulmonary bypass, and venoarterial extracorporeal membrane oxygenation; these can produce the most rapid rate of rewarming (6-9 C/hr). (Choice C) Cardiac arrhythmias are common with significant hypothermia. Atrial arrhythmias (eg, atrial flutter or fibrillation) usually convert spontaneously to sinus rhythm with correction of hypothermia. However, ventricular arrhythmias should be treated according to advanced cardiac life support protocols. Educational objective: Initial treatment of moderate hypothermia includes supportive care, active and passive external rewarming, and warmed intravenous fluids to maintain blood pressure and circulation. __________ References: The evaluation and management of accidental hypothermia. (http://www.ncbi.nlm.nih.gov/pubmed/14744270)

A 45-Year-Old Homeless Man Is Found Unresponsive on the Street