Emergencies

Question 1

What is neuroleptic malignant syndrome?

Answer 1

Rare but potentially life threatening idiosyncratic reaction to antipsychotic drugs

Thought to be due to central D2 receptor blockade or dopamine depletion leading to impairment of homeostasis

Question 2

What are the risk factors for developing NMS?

Answer 2

Use of neuroleptic drugs and genetic susceptibility
Withdrawal of Parkinson's meds
Use of high doses or depot
Patient agitation/catatonia
High ambient temp and dehydration
Previous episode

Question 3

What are the symptoms of NMS?

Answer 3

Dyspnoea due to hypoventilation caused by muscle rigidity

Dysphagia
Difficulty walking, development of shuffling gait
Seizures, chorea

Question 4

What are the signs of NMS?

Answer 4

Hyperthermia above 38
Muscular rigidity - lead pipe type

Five of the following to diagnose:
Changed mental status
Tachycardia
Hypotension/hypertension
Tremor
Incontinence
Diaphoresis (excessive sweating) or sialorrhoea - drooling
Increased creatine phosphokinase
Metabolic acidosis
Leukocytosis
Exclusion of other illnesses

Question 5

What are the differentials of NMS?

Answer 5

Dystonic reaction 
Serotonin syndrome
Malignant hyperpyrexia
Recreational drug toxicity
Lethal catatonia - catatonia with rigidity and raised CK
Organophosphate poisoning
Heatstroke
Encephalitis

Question 6

What are the investigations for NMS?

Answer 6

FBC - leukocytosis
U&Es - metabolic disturbance
Hypocalcaemia
LFTs
CK elevated
Coagulation studies
Urinary drug screen
Consider sepsis - CXR too
LP to exclude diagnoses

Question 7

What is the treatment for NMS?

Answer 7

Airway and breathing need protection
Agitated patients may need IV benzos, avoid restraint
IV fluids for dehydration
Offending drug discontinued
Overdose - activated charcoal
If rhabdomyolysis or AKI - alkalinisation of urine and dialysis
ECT if meds fail
Bromocriptine/dopaminergic agents if severe

Question 8

What are the complications of NMS?

Answer 8

Cardiac arrest
Rhabdomyolysis
AKI
Seizures
Respiratory failure
DIC
Aspiration pneumonitis
Hepatic failure
PE

Question 9

What is serotonin syndrome?

Answer 9

Serotonin toxicity

Drug induced - too much serotonin in the synapses of the brain

Question 10

What are the most common implicated drugs of serotonin syndrome?

Answer 10

MAOIs
SNRIs
SSRIs

Other causes include antiemetics, recreational drugs, analgesics e.g. tramadol or pethidine

Question 11

What is the presentation of serotonin syndrome?

Answer 11

Autonomic hyperactivity
Neuromuscular abnormality
Mental status changes

Likely only in the setting of starting or increasing the dose of a potent serotonergic drug

Symptoms usually occur within 6 hours of taking
Tremor, akathisia, diarrhoea early features

Question 12

What examination signs are found in serotonin syndrome?

Answer 12

Autonomic disturbance - HTN, tachycardia, hyperthermia, hyperactive bowel sounds, sweating

Neuromuscular dysfunction - tremor, clonus, hypertonicity, hyperreflexia

Altered mental state - anxiety, agitation, confusion, coma

Question 13

What are the differentials of serotonin syndrome?

Answer 13

Malignant hyperthermia
NMS
Anticholinergic poisoning
Catatonia
Dystonia
Hyperthyroidism
Tetanus
Delirium tremens
Encephalitis, meningitis

Question 14

What are the investigations for serotonin syndrome?

Answer 14

Check U&Es, CK
Toxicology screen
FBC, blood culture, LFT
CXR, CT, LP fever/altered mental state, resp comp

Question 15

What is the management of serotonin syndrome?

Answer 15

Likely causative drug stopped
Refer those with MAOI or SSRI and severe symptoms to hospital
Activated charcoal if overdose
Supportive measures e.g. iV fluids, benzos for agitation

Question 16

What are the complications of serotonin syndrome?

Answer 16

Hyperthermia can lead to metabolic acidosis, rhabdomyolysis, AKI, DIC
Temp over 40.5 - paralysis, ventilation, ice bath

Seizures
Aspiration pneumonia
Respiratory failure

Question 17

What is an acute dystonic reaction?

Answer 17

Characterised by involuntary contractions of muscles of the extremities, face, neck, abdomen, pelvis or larynx.

Leads to abnormal movements or postures.

Symptoms may be reversible or irreversible
Usually occur shortly after initiation of an offending agent

Question 18

What drugs commonly cause an acute dystonic reaction?

Answer 18

Antipsychotics

Antiemetics

Question 19

What can be the presentation of acute dystonic reactions?

Answer 19

Buccolingual crisis - trismus, dysarthria, dysphagia, tongue protrusion

Oculogyric - spasm of extraocular muscles

Torticolic crisis - abnormal asymmetric head or neck position

Tortipelvic - abnormal contractions of abdominal wall, hip, pelvic musculature

Laryngeal dystonia - dysphonia, stridor

Pseudomacroglossia - sensation of tongue swelling and protrusion

Question 20

What is the management of acute dystonic reaction?

Answer 20

Balance disrupted dopaminergic-cholinergic balance in basal ganglia
Discontinue offending agent

Diphenhydramine and benztropine, IV

Supportive measures e.g. oxygen, assisted ventilation if indicated

Question 21

What levels of lithium are associated with toxicity?

Answer 21

> 1.5, >2 may be associated with serious toxicity

Also be suspected at therapeutic levels in compromised patients with relevant symptoms

Question 22

Why might lithium toxicity occur?

Answer 22

Intentional overdose
Chronic treatment due to reduced drug excretion - dehydration, worsening renal function, concurrent infections, drug interactions

Question 23

What are some of the findings in lithium toxicity?

Answer 23

Anorexia, diarrhoea and vomiting.
Drowsiness, apathy, restlessness.
Dysarthria.
Dizziness, ataxia, inco-ordination, muscle twitching, coarse tremor.

Question 24

What are some of the findings in severe toxicity of lithium?

Answer 24

Hyperreflexia, convulsions.
Collapse, coma.
Renal failure, dehydration, circulatory collapse (may need haemodialysis).
Hypokalaemia.
Death.

T wave inversion potentially

Question 25

What is the treatment for toxicity?

Answer 25

Stop lithium, check level and refer for urgent assessment (encourage fluids, stop diuretics, monitor electrolytes and monitor renal function).

If severe, admit as emergency and whole bowel irrigation may be considered if large quantities have been ingested

Question 26

What is drug induced (clozapine) agranulocytosis?

Answer 26

Potentially life threatening reaction, characterised by profound decrease in neutrophil count and susceptibility to infection

Question 27

What defines agranulocytosis?

Answer 27

A neutrophil count of less than 0.5 x 10 ^ 9 / L

Question 28

What monitoring is required for clozapine?

Answer 28

Close monitoring of FBC -weekly for 18 weeks, then fortnightly for up to a year, then monthly

Question 29

What is the treatment of agranulocytosis?

Answer 29

Stop clozapine
Stop any other potentially marrow suppressing drugs e.g. sodium valproate
Avoid other antipsychotics for a couple of weeks where possible
Contact consultant haem as an amaergency
Avoid sources of infection, consider prophylactic broad-spectrum antibiotics
Lithium can be used to increase WCC and neutrophil count
Granulocyte colony stimulating factor can be used

Question 30

What are the symptoms of agranulocytosis?

Answer 30

May be asymptomatic
Sudden fever, rigors, sore throat
Infection of any organ or sepsis may be rapid