Cases That Test Your Skills

The psychotic pot smoker

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When police bring Mr. C to the emergency department, he’s agitated, confused, and hallucinating. He claims someone tampered with his marijuana. What’s causing his psychosis?


 

References

CASE: Scared and confused

Mr. C, age 28, presents to the emergency department (ED) in police custody with agitation and altered mental status. Earlier that evening, Mr. C’s girlfriend noticed he was talking to himself while watching television. A few hours later, Mr. C thought someone was breaking into his house. Mr. C ran out of the house screaming for help, broke his neighbor’s window, and eventually called the police. When the police arrived Mr. C was wearing only his underwear, shaking, and bleeding from his hands. He said he was afraid and refused to respond to police instructions. Police officers used an electronic stun gun to facilitate transport to the hospital.

Mr. C admits to smoking 3 to 4 marijuana joints daily for the past 16 years. His last drug use was 2 hours before his symptoms began. Mr. C suggests that someone may have adulterated his marijuana joint but he has no factual basis for this accusation. He denies using alcohol and other illicit drugs and has no personal or family psychiatric history. He denies recent fever, loss of consciousness, chest pain, weakness, myalgia, or headache. Medically stable, his only complaint is mild hand pain.

Mr. C is alert, awake, and oriented to his name, and he responds properly to questions. He is tachycardic (101 bpm), his blood pressure is 149/57 mm Hg with normal S1 and S2 sounds, and he has no meningismus or nystagmus. Glasgow Coma Scale score is 15. He has increased deep tendon reflexes on the right upper and lower limb with good hand-grip and multiple abrasions and lacerations on his hands.

The authors’ observations

New-onset psychosis can have a wide differential diagnosis, particularly when reliable history is not available. Mr. C’s allegation that someone tampered with his marijuana raises 2 possibilities: embalming fluid (form-aldehyde) toxicity or PCP intoxication.

Embalming fluid toxicity can cause:

  • agitation and sudden unpredictable behavior
  • confusion or toxic delirium
  • coma or seizure
  • cerebral and pulmonary edema or death in severe cases.

The terms “wet,” “sherm,” “fly,” “amp,” or “illy” are used to describe a marijuana cigarette that has been dipped into embalming fluid, dried, and then smoked.1 The effect is similar to that of PCP and causes extreme hallucinations. Reported highs last 30 minutes to 1 hour.2

Symptomatology of PCP intoxication may be indistinguishable from functional psychosis (Table 1).3 Visual, auditory, and tactile misperceptions are common and highly changeable disorientation often is accompanied by alternating periods of lethargy and fearful agitation. These patients typically show catatonic posturing and/or stereotyped movement. Somatic sensations appear to be disassociated; patients may misperceive pain, distance, and time. Patients taking PCP rarely admit to true hallucinations; however their thinking usually is grossly disoriented.4 Symptoms of delirium may last from 30 minutes to 6 hours in 80% of cases; 12% of patients may remain symptomatic for 12 hours. Violent behavior and agitation usually lasts only a few hours.5

Long-term marijuana abuse can lead to psychosis6 but acute onset is not typical, and recent prospective trials raised doubts that cannabis would be a sole factor.7 Instead, cannabis may be 1 of several factors that contribute to psychosis, particularly in patients who are predisposed.

Table 1

Phencyclidine (PCP) intoxication: What to look for

FindingsPercentage of cases
Nystagmus57.4%
Hypertension57.0%
Delirium36.9%
Violent behavior35.4%
Agitation34.0%
Tachycardia30.0%
Bizarre behavior28.5%
Hallucinations/delusions18.5%
Unconsciousness10.6%
Lethargy/stupor6.6%
Hypothermia6.4%
Generalized rigidity5.2%
Profuse sweating3.9%
No behavior effect3.5%
Grand mal seizure3.1%
Source: Reference 3

Possible neurologic causes

Complex partial seizures—also known as psychomotor epilepsy—are caused by a surge of electrical activity in the brain. Seizures often involve 1 of the brain’s temporal lobes but can affect any brain region. Symptoms include:

  • impaired social interaction
  • inability to control one’s movements
  • alogia
  • amnesia.

Episodes typically start with a blank stare followed by automatisms. The actions and movements often are unorganized or confused. Motor symptoms typically last for 1 to 2 minutes and confusion persists for another 1 to 2 minutes.8 In rare cases, a patient may become agitated or engage in behaviors such as undressing. Complex partial seizures may cause a person to run in apparent fear, cry out, or repeat a phrase.9 Electroencephalogram, CT, MRI, or positron-emission tomography scan could reveal any intracranial focus of complex partial seizures.

We suspect PCP or embalming fluid intoxication and initiate supportive therapy.

EVALUATION: Still confused

Initial baseline labs include a urine drug screen (UDS), chest radiography, ECG, and head CT. Mr. C’s UDS is positive for cannabis. A specific PCP assay is negative. White blood cell count (WBC) is 22,000/μL with high neutrophil count (88%), creatine kinase (CK) is 458 U/L, and urinalyis reveals protein 75 mg/dL and ketone 50 mg/dL. Head CT is negative for any acute process (click here for detailed description of Mr. C�s hospital course while in the ED).

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