The patient who is unconscious after taking 3,4-methylenedioxymethamphetamine (MDMA or Ecstasy) likely has experienced water intoxication which causes a profoundly low sodium level. MDMA causes severe thirst that the patient attempts to quench with copious water. In the woman of childbearing age, normal hormones place the patient at increased risk for brain herniation due to cerebral edema. A high sodium level is not expected in this patient. Although the patient has decreased level of consciousness, the patient’s vitals are within defined limits; this indicates the patient is not experiencing respiratory depression or failure, which would lead to a high PCO2. Hyperventilation is also not indicated by the patient’s vital signs, so a low PCO2 is unlikely as well.