Neuroleptic malignant syndrome Flashcards
Define neuroleptic malignant syndrome.
Acute potentially life threatening complication or antipsychotic/dopamine antagonist treatment or acute withdrawal of it
A disorder of thermoregulation and neuromotor control
How common is NMS?
<1% of patients taking antipsychotics affected
Has declined over last 20yrs which may be due to greater awareness or more second-generation antipsychotic use
What is the pathophysiology of NMS?
Not well established - acute imbalance or dysregulation of CNS neurotransmitters is strongly suspected
What are the risk factors for NMS?
- High dose typical antipsychotics - usually within 3-9 days of starting treatment; has been reported with antidepressants but less common
- Rapid dose changes or withdrawal
- Male gender
- Older age
- Pre-existing brain abnormality e.g. dementia, trauma, Wilson’s, PD.
- Dehydration
What are the clinical features of NMS?
- Muscle rigidity
- Hyperthermia
- Hyporeflexia
- Diaphoresis, urinary incontinence
- Autonomic dysregulation e.g. tachycardia, hypotension
- Altered consciousness - confusion, delirium, stupor
- Hypermetabolism
How do you diagnose NMS?
- Raised CK - typically >1000
- Raised WCC
- Deranged LFTs - may get liver failure
- Deranged renal function (due to rhabdo from raised CK) - e.g. myoglobinuria, hyperkalaemia, hyper/hyponatraemia
Other:
* ECG - long PR, QRS, QT; ST or T wave abnormalities
* CT scan - exclude brain abnormality
* Urine/blood culture
* CXR - increased risk of aspiration
What is the management of NMS?
- Stop causative agent + transfer to ITU
- Support care:
- Fluids - treat the rhabdomyolysis, consider urine alkalinisation
- Cooling - treat hyperthermia
- Sedation with benzodiazepines - relax muscles and manage agitation
- Bromocriptine (DA) or Dantrolene - muscle relaxant if no response to supportive treatment to treat hyperthermia and rigidity
Other:
* ECT - case reports; may further elevate CK
When can antipsychotics be started again after NMS?
Wait at least 2 weeks after NMS
What are some signs of severe NMS requiring critical care?
Moderate/severe NMS
Severe hyperthermia >38.5C despite cooling
Coma
Compromised ventilation
Acute renal failure or severe hyperkalaemia
What is the classification of severity of NMS?
What are the complications of NMS?
- Sepsis
- AKI
- Status epilepticus
- Rhabdomyolysis
- PE - due to immobility
- Aspiration
- Cognitive deficits
- Worsening psychosis
What is the prognosis with NMS?
Mortality varies - studies report 8-9%
Recurrence is as high as 30%