9. Psychiatric Emergencies

Question 1

What is neuroleptic malignant syndrome?

Answer 1

!MEDICAL EMERGENCY!
Rare, idiosyncratic reaction to neuroleptic medications (aka antipsychotics) caused by a sudden hypodopaminergic state
- can also result from abrupt discontinuation of dopaminergic agents in Parkinson’s Disease

Question 2

Risk factors of NMS developing

Answer 2

Typically high potency neuroleptics, IM preparations, more severe mental illness

Question 3

Clinical features of NMS

Answer 3

FARM / FEVER

Fever - hyperthermia (does not respond to antipyretics)
Autonomic instability
Rigidity (must have this) -> rhabdomyolysis -> raised serum CK, myoglobinuria -> AKI
Mental state - altered

Fever
Encephalopathy
Vital signs instability
Elevated CK/WBC
Rigidity

Question 4

Immediate management of NMS

Answer 4

Stop antipsychotics
Supportive measures: bed rest, cooling, o2

Question 5

Definitive management of NMS

Answer 5

• Dopamine agonist (bromocriptine)
• Dantrolene
• BZD
• ECT

Question 6

Ix for NMS

Answer 6

TRO other causes for presentation eg MRI/LP
Serum Ck usually very high
Possible leukocytosis

Question 7

Serotonin syndrome

Answer 7

Results from an excess of serotonergic activity in the CNS

!MEDICAL EMERGENCY!

Question 8

How does serotonin syndrome commonly occur?

Answer 8

1. Use of MAOi + SSRI
2. Overdose of SSRI
3. Switching from one SSRI to another without an adequate washout period

Question 9

Clinical features of serotonin syndrome

Answer 9

1. Mental status change: anxiety/agitation to extreme confusion
2. Autonomic hyperactivity: tachycardia, tremor, flushing, hyperthermia, excessive sweating
3. Neuromuscular abnormalities: generalised hyperreflexia, clonus, myoclonus, rigidity

HARMFUL TIP

Hyperreflexia
Autonomic instability
Rigidity
Myoclonus
Fever
Unconsciousness (AMS, drowsiness)
Lethargy

Tremor
Increase sweating
Pupillary dilatation

Question 10

NMS vs serotonin syndrome

Answer 10

Serotonin syndrome
- a/w antidepressants (vs antipsychotics in NMS)
- more rapid onset and development
- less rigidity
- may lead to hyperkinesia
- hyperactive bowel sounds

Question 11

Immediate management for serotonin syndrome

Answer 11

Stop antidepressants
Supportive measures

Question 12

Definitive management for serotonin syndrome

Answer 12

BZD
ECT

Question 13

Antidote for paracetamol overdose

Answer 13

N-acetylcysteine
*100% protective when given within 8 hours of ingestion

Question 14

How does NAC work?

Answer 14

NAC prevents the binding of NAPQI (toxic metabolite of paracetamol ) to hepatocytes

Question 15

When should the first blood paracetamol level be taken in a paracetamol overdose?

Answer 15

At or after 4 hours post-ingestion