A 30-year-old man is brought to the emergency department by an ambulance after a gas station attendant noticed the patient disoriented and wandering aimlessly. The patient has had nausea, vomiting, and dizziness. Emergency department records indicate that the patient has a history of schizophrenia, but he cannot remember the names of his medications. He also has limited memory of the previous day. The patient smokes cigarettes occasionally and does not use alcohol or illicit drugs. Temperature is 41.1 C (106 F), blood pressure is 90/60 mm Hg, pulse is 128/min, and respirations are 26/min. The patient is lethargic and appears disheveled and sunburned; he is oriented to person only. The skin and oral mucous membranes are dry. The lungs are clear to auscultation. The heart rhythm is regular with no murmurs. Muscle tone is moderately decreased and reflexes are normal. He moves all extremities to command. Laboratory results are as follows: Urine drug screen is positive for methamphetamines. Chest x-ray is clear. CT scan of the head without contrast shows no acute intracranial abnormalities. Which of the following is the most appropriate immediate step in management of this patient?

Question

A 30-year-old man is brought to the emergency department by an ambulance after a gas station attendant noticed the patient disoriented and wandering aimlessly.  The patient has had nausea, vomiting, and dizziness.  Emergency department records indicate that the patient has a history of schizophrenia, but he cannot remember the names of his medications.  He also has limited memory of the previous day.  The patient smokes cigarettes occasionally and does not use alcohol or illicit drugs.  Temperature is 41.1 C (106 F), blood pressure is 90/60 mm Hg, pulse is 128/min, and respirations are 26/min.  The patient is lethargic and appears disheveled and sunburned; he is oriented to person only.  The skin and oral mucous membranes are dry.  The lungs are clear to auscultation.  The heart rhythm is regular with no murmurs.  Muscle tone is moderately decreased and reflexes are normal.  He moves all extremities to command.  Laboratory results are as follows:  Urine drug screen is positive for methamphetamines.  Chest x-ray is clear.  CT scan of the head without contrast shows no acute intracranial abnormalities.  Which of the following is the most appropriate immediate step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c014_ed72_8f63_339d9798afb8_MD0005_00 This patient who is confused and sunburned has severe hyperthermia, raising suspicion for nonexertional heat stroke. Most cases arise in those who are unable to leave hot environments due to a neurologic/psychiatric disorder, a physical disability, illicit drug use (eg, amphetamines), or thermoregulation abnormalities due to obesity or certain medications (eg, antipsychotics). Heat stroke is usually marked by a body temperature >40 C (104 F) and is typically associated with nausea, vomiting, tachycardia, confusion, seizure, and/or hypotension. Laboratory examination frequently reveals rhabdomyolysis, acute renal and hepatic injury, and severe acidosis. Hypokalemia and hypophosphatemia are common early on (whereas hyperkalemia and hyperphosphatemia can develop at a later time), and these electrolyte abnormalities can affect muscle function and exacerbate rhabdomyolysis. Aggressive management is required to prevent death. Evaporative and convective cooling (water misters and fan) is considered first-line therapy. Ice packs or ice water baths are also sometimes used but may be more difficult to tolerate. (Choice A) Antipyretics (eg, acetaminophen) are not useful in heat stroke and can worsen the associated hepatic injury. (Choice B) Broad-spectrum antibiotics are often used in patients with suspected sepsis, which can present with temperature elevation, hypotension, tachycardia, and confusion. This patient who is sunburned with hypovolemia (dry skin/mucous membranes, elevated blood urea nitrogen to creatinine ratio), rhabdomyolysis, and a dramatically elevated temperature is more likely to have heat stroke. (Choice C) Dantrolene is used in the treatment of malignant hyperthermia and neuroleptic malignant syndrome. Although these conditions can cause hyperthermia, acidosis, and rhabdomyolysis, they are typically characterized by muscle rigidity and diaphoresis. This sunburned patient with decreased muscle tone and dry skin is more likely to have heat stroke. (Choice E) Lorazepam can be used to treat acute methamphetamine intoxication. Severe intoxication can cause hyperthermia, tachycardia, renal insufficiency, and metabolic acidosis, but patients usually also have hypertension (not hypotension), severe agitation, and psychosis. Educational objective: Nonexertional heat stroke is typically marked by body temperature >40 C (104 F), nausea, vomiting, confusion, seizure, tachycardia, and/or hypotension. Most cases arise in those who are unable to leave hot environments or in those who have abnormal thermoregulation. First-line therapy is evaporative and convective cooling with water misters and a fan. References: Cooling methods in heat stroke. (http://www.ncbi.nlm.nih.gov/pubmed/26525947) Heat illness in the emergency department: keeping your cool. (http://www.ncbi.nlm.nih.gov/pubmed/25422847)

A 30-Year-Old Man Is Brought to the Emergency Department by an Ambulance