Altered Mental Status in a Young Man Picked Up On the Street

Discussion

The rhythm strip demonstrated sinus tachycardia, with peaked symmetric T waves that are consistent with hyperkalemia. In addition, hyperkalemia can often be associated with small or absent P waves and a widening of the QRS complex. In the setting of tachycardia, this can give the appearance of bundle branch block (BBB) (aberrancy) or ventricular tachycardia (as was the concern here, given the patient's hemodynamic instability). ECG abnormalities can reveal a cardiac effect of hyperkalemia, but they do not always correlate with the severity of the hyperkalemia; therefore, it is important to corroborate the ECG evidence with the laboratory values.

The hyperthermia and convulsions in this patient likely led to a severe metabolic acidemia and rhabdomyolysis, with resultant hyperkalemia. The laboratory analysis showed a white blood cell (WBC) count of 19.1 × 10³/µL (19.1 × 10⁹/L), with no left shift. The coagulation tests and cardiac troponin results were normal. The urine microscopy and chest x-ray were performed to investigate for a source of infection; findings were normal. A serum toxicology screen, including for aspirin and acetaminophen, was negative; however, a urine toxicology screen was positive for cocaine, methadone, benzodiazepines, and opiates (but it was negative for amphetamines, barbiturates, phencyclidine [PCP], and oxycodone). The chemistry panel showed a potassium level elevated at 6.9 mEq/L (6.9 mmol/L; normal range is <5.0 mEq/L), a carbon dioxide level of <5 mEq/L (<5 mmol/L), and a creatinine level of 1.7 mg/dL (150.28 µmol/L). The patient's serum glucose level was measured at 170 mg/dL (9.44 mmol/L), and his serum lactic acid level was 25.23 mg/dL (2.8 mmol/L). The creatine kinase level was elevated at 710 units/L (710 U/L), as were the aspartate transaminase (AST) level at 86 units/L (86 U/L) and the alanine transaminase (ALT) level at 123 units/L (123 U/L). His urine, while initially negative, turned red on a repeat specimen (while still in the ED). Treatment for hyperkalemia was initiated with calcium gluconate, dextrose plus insulin, and sodium bicarbonate. Copious IV fluids were also given.

Cite this: Andréa B. Lese, Rick G. Kulkarni. Altered Mental Status in a Young Man Picked Up On the Street - Medscape - Aug 24, 2010.

Commenting is limited to medical professionals. To comment please Log-in.

Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.

My Alerts