A 45-year-old man is brought to the emergency department due to a progressively worsening headache and difficulty breathing. Yesterday morning, he arrived in Colorado from Kansas for a ski vacation. The patient was feeling well until last night, when he began experiencing a headache and shortness of breath with exertion. The headache came on gradually, is generalized, and affects his ability to sleep. This morning, he developed vomiting and dizziness. The patient has had no fever, neck pain, or chest pain. He has no significant medical history and exercises daily. Temperature is 37.2 C (99 F), blood pressure is 130/80 mm Hg, pulse is 99/min, and respirations are 22/min. Pulse oximetry is 96% on room air. The patient is mildly drowsy but can converse. He is oriented to time, place, and person. Cardiopulmonary examination is normal. There are no focal neurologic findings. The skin is normal. Which of the following is the most appropriate next step in management?

Question

A 45-year-old man is brought to the emergency department due to a progressively worsening headache and difficulty breathing.  Yesterday morning, he arrived in Colorado from Kansas for a ski vacation.  The patient was feeling well until last night, when he began experiencing a headache and shortness of breath with exertion.  The headache came on gradually, is generalized, and affects his ability to sleep.  This morning, he developed vomiting and dizziness.  The patient has had no fever, neck pain, or chest pain.  He has no significant medical history and exercises daily.  Temperature is 37.2 C (99 F), blood pressure is 130/80 mm Hg, pulse is 99/min, and respirations are 22/min.  Pulse oximetry is 96% on room air.  The patient is mildly drowsy but can converse.  He is oriented to time, place, and person.  Cardiopulmonary examination is normal.  There are no focal neurologic findings.  The skin is normal.  Which of the following is the most appropriate next step in management?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d1d5_a8ed_bc81_fbb06e2d6a75_MD0003_00 This patient's initial symptoms (ie, gradual headache, sleep difficulty, dyspnea with exertion) are likely due to acute mountain sickness (AMS). The development of drowsiness suggests progression to high-altitude cerebral edema (HACE), a rare, life-threatening emergency. High-altitude illness results from abrupt ascent to high altitude without acclimatization. AMS and HACE share the same pathophysiology, which is believed to involve hypoxia-induced (eg, low PaO₂) cerebral vasodilation, causing capillary leakage and eventually cerebral edema. Many patients whose condition progresses to HACE also have evidence of high-altitude pulmonary edema. hypoxia-induced AMS occurs within the first 24 hours of arrival at high altitude and involves relatively mild symptoms of fatigue, headache, and disturbed sleep. It is common and generally resolves within a few days with or without treatment (eg, oxygen, acetazolamide). HACE can be viewed as end-stage AMS, generally occurring 12 hours to 3 days after AMS onset. The development of encephalopathic symptoms (eg, drowsiness, confusion, ataxia) signals this progression. If left untreated, coma and death due to brain herniation can occur within 24 hours. HACE is diagnosed clinically; treatment is aided by dexamethasone, which can decrease cerebral swelling and is administered at the first sign of symptoms. Definitive management requires immediate descent to lower altitude. (Choice B) Doxycycline is used to treat Rocky Mountain spotted fever (RMSF), a tick-borne rickettsial infection. Patients can have headache and confusion, but fever and rash are also common. RMSF usually occurs during the summer and is rarely seen in winter. (Choice C) Furosemide, a loop diuretic, is used to treat edema from volume overload. The edema in HACE is believed to involve hypoxia-induced vascular permeability, not volume overload. Volume depletion occurs in many patients at high altitude because of bicarbonate diuresis, fluid shift from the intravascular space, and suppression of aldosterone. (Choice D) Intubation and mechanical ventilation are indicated for respiratory failure or airway protection. This patient has no evidence of significant respiratory difficulty or inability to protect the airway. (Choice E) Low-molecular-weight heparin can be used to treat cerebral sinus venous thrombosis, which presents with signs of increased intracranial pressure (eg, headache, drowsiness, vomiting) but not shortness of breath. In addition, imaging should be performed before initiating anticoagulation. Educational objective: Acute mountain sickness can progress to high-altitude cerebral edema, a life-threatening condition characterized by ataxia and declining mental function that can occur after rapid ascent to high altitude. Early treatment with dexamethasone can improve symptoms; definitive treatment requires immediate descent. References: Acute high-altitude illness: a clinically orientated review. (http://www.ncbi.nlm.nih.gov/pubmed/26516505)

A 45-Year-Old Man Is Brought to the Emergency Department Due