An older-appearing man of unknown age is brought to the emergency department by paramedics on New Year's Eve. They found him minimally responsive and lying on the side of a street. In the emergency department, the patient's core body temperature is 29 C (84.2 F) , blood pressure is 70/30 mm Hg, heart rate is 40/min, and respirations are 6/min and shallow. His oxygen saturation is 90% on 5 L oxygen. On examination, the patient remains unresponsive to verbal stimuli and his breath smells of alcohol. His pupils are normal and symmetric but have a sluggish reaction to light. Lung examination reveals crackles bilaterally. Cardiovascular examination reveals bradycardia with an irregular pulse. Neurologic examination is difficult to perform but shows marked hyporeflexia throughout. An initial ECG shows sinus bradycardia with frequent premature ventricular complexes. Capillary blood glucose is 315 mg/dL. Paramedics have started an infusion of warmed normal saline via 16-g peripheral access. The patient has also received one dose of intravenous thiamine. Item 1 of 2
Which of the following is the most appropriate next step in management of this patient?

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Explanation: 11ec2b69_c012_f19e_8f63_2595a7b9d488_MD0005_00 This patient is suffering from moderate hypothermia. Mild hypothermia (core body temperature of 32-35 C [90-95 F]) may cause only increased shivering, ataxia, slurred speech, tachycardia, and tachypnea. Moderate hypothermia (core temperature of 28-32 C [82-90 F]) is characterized by marked central nervous system depression along with hypoventilation, hypotension, bradycardia, hyporeflexia, and cardiac conduction abnormalities. Severe hypothermia (core temperature <28 C [82 F]) can cause marked hypotension, areflexia, coma, malignant ventricular arrhythmias (ventricular fibrillation), and asystole. In light of this patient's hypoventilation, altered mental status, and hypoxemia, the next step in management is endotracheal intubation to provide adequate ventilation and protect the airway. Endotracheal intubation should protect against aspiration, help in oxygenation, and allow for suction of cold-induced bronchial secretions. Active rewarming measures (eg, heating pads, warm blankets) are also indicated. (Choice A) Bradycardia is a physiologic response to hypothermia and resolves with rewarming. Atropine or cardiac pacing is not required unless the bradycardia persists after the temperature is corrected. (Choice C) Patients with hypothermia should be handled gently as rough physical handling can precipitate serious ventricular arrhythmias. Even the myocardial irritation that could occur during placement of jugular or subclavian lines can cause cardiac arrhythmias. If central line placement is required, femoral lines are preferred. (Choice D) Many nondiabetic patients with moderate-to-severe hypothermia are hyperglycemic as insulin action stops at <30 C [86 F]. Warming these patients typically results in lowering of serum glucose. (Choice E) Pulmonary edema is common in significant hypothermia, and does not necessarily indicate additional pathology. If it does not improve with rewarming, additional intervention can be considered at that time. Educational objective: Endotracheal intubation is necessary in the unconscious hypothermic patient for adequate ventilation and airway protection. Hypothermic patients should be handled gently to prevent cardiac arrhythmias.

An Older-Appearing Man of Unknown Age Is Brought to the Emergency