Download NMS vs EPSE vs SS vs MH Fact Sheet - Improving

Neuroleptic Malignant Syndrome
Serotonin syndrome
Malignant Hyperthermia
Epidemiology
Occurs in 0.5-3% patients on drugs (rare); 50% recurrence rate if re-challenged; 5-30% mortality; M:F 2:1; diagnosis of
exclusion
10% mortality rate
70% mortality untreated
7% mortality with trt
Pathophysiology
Dopamine blockade in basal ganglia and hypothalamus  hyperthermia due to sustained muscle contraction (EPSE) or
Incr 5-HT
Genetic abnormality of L-type Ca channel
in SR  incr intracellular Ca and muscle
contraction; autosomal dominant
Causes
Occurs after starting / incr dose / adding 2nd drug, within 2/52 (in 2/3); may occur after months; after IV meds (esp
haloperidol); idiosyncratic reaction, not toxicity
Patient factors: young, male, agitated, organic brain disease, dehydration, malnutrition, PMH NMS
Drug factors: high potency (eg. Haloperidol), high dose, rapid incr in dose, depot meds
Usually due to >1 drug
Sertraline (most common)
Inhalational anaesthetic
elevated T set point; also incr Ca release from SR
Typical/aytpical antipsychotics (haloperidol, chlorprom, olanzapine, quetiapine, risperidone)
Antiemetics (chlorpromazine, maxalon, stemetil)
Antihistamines
Causes of EPSE: MAOI +/- TCA, SSRI, SNRI, Lithium, amphetamine, cocaine, MDMA
Assessment
Hx: onset over hrs - 3/7
Fever (>38 in >90%; ETT indications as per SS)
---------------------------------------------------------------------------------------------------------------------------------------------------------------------Muscle rigidity (Parkinsonian in >90%, leadpipe)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------NM: tremor, incontinence; decr reflexes
SSRIs
Other antidepressants: Li (incr post-synaptic
5-HT stimulation), moclobemide and other MAOI,
citalopram, St John’s wort, TCA, SSNRI
Illicit drugs: LSD, cocaine, amphetamines, E
Analgesia: Pethidine, fentanyl, tramadol,
sumatriptan
(halothane, sevoflurane, desflurane,
isoflurane)
Depolarising muscle relaxants
(sux)
Others (ketamine, phenothiazines,
MAOI)
Chlorpheniramine
AntiParkinsons: L dopa, bromocriptine
Onset over hrs (faster than NMS; 60% within 6hrs);
resolves over hrs (24-48hrs if severe)
Onset over mins –hrs
Hx: FH
Fever (milder than in NMS)
Fever: >38.8
--------------------------------------------------------------------Muscle rigidity (esp legs; occurs late)
------------------------------------------------------Muscle rigidity: generalised
------------------------------------------------------NM hyperactivity: akathesia, hyperreflexia,
clonus (esp legs; ocular – distinguishable from
rigidity, trismus
------------------------------------------NM changes: decr reflexes
nystagmus as no fast component); repetitive rotation
of head with neck in mod extension; myoclonic jerks;
seizures
----------------------------------------------------------------------------------------------------------------------------------------------------------------------Autonomic instability: incr HR / RR / BP, sweating but pallor, mydriasis or normal pupils; normal BS’s
----------------------------------------------------------------------------------------------------------------------------------------------------------------------Altered LOC (may be dysphagia, aphonia, dysarthria, staring, bradykinesia)
---------------------------------------------------------------------------------------------------------------------------------------------------------------------- RS/CV failure, ARF, MOF, DVT, NCPO, PE, pneumonia, seizures, rhabdo, dehydration
EPSE:
Early reversible (hrs-days): with high potency
1) Dystonic reaction: oculogyric crisis (esp eye, tongue, facial, neck muscles); normal LOC; no muscle rigidity between
---------------------------------------------------------------------Autonomic hyperactivity: incr HR / RR / BP,
sweating, mydriasis, hyperactive bowel
sounds, diarrhoea
-------------------------------------------------------Altered LOC: agitation, confusion, change in
behaviour / cognition
-------------------------------------------------------------------- metabolic acidosis, rhabdo (rare), ARF, seizures,
DIC
------------------------------------------Autonomic changes: Incr HR / BP /
RR, normal pupils; ileus; sweaty
and mottled
------------------------------------------Altered LOC: agitation
------------------------------------------------------ resp acidosis (incr ETCO2) and
metabolic acidosis; rhabdo
spasms; 1-5/7 after starting trt (50% 2/7, 95% 5/7); esp in young males, cocaine, hyperventilation, hypoCa
2) Akathesia: restlessness; onset 5-60/7
Late reversible (days-wks): with low potency
1) Parkinsonism: akinesia, cogwheel rigidity, resting tremor, shuffling gait, masked facies, drooling; onset 5-30/7
2) NMS
Irreversible (mths-yrs):
1) Tardive dyskinesia
Investigation
Bloods: WCC up to 30; CK >1000; incr LFTs; incr K / phos / Ur / Cr / plt; myoglobinuria; ARF; metabolic acidosis; incr Cr
Rhabdo rare
Mng
Stop cause; aggressive supportive care; cooling; IVF; trt rhabdo; can use ECT in severe NMS refractory to medical trt
25% ETT rate (do if coma, recurrent seizures, incr T
>39.5, severe rigidity); benzos; barbs and paralysis if
severe; GTN or nitroprusside for HTN; observe at
least 8hrs
CK >20,000, myoglobin in urine, K >6;
incr phos; muscle biopsy; ARF
Avoid: sux (use roc)
Bromocriptine: 2.5mg PO TDS  incr to max 5mg Q4h; dopamine agonist; in mod/severe cases
Dantrolene: 1mg/kg IV load  1mg/kg QID IV; controversial; in severe cases
For dystonic reaction:
Benztropine: 1-2mg IV  rpt at 15mins if needed  discharge on 2mg TDS PO for 1-2/7
Diphenhydramine: 1-2mg/kg IV (max 50mg)  25-50mg TDS PO
Benzo’s
Cyproheptadine: 8mg PO  4mg PO Q4h;
5-HT receptor antagonist
Chlorprothixine: IM alternative to above
Chlorpromazine 50-100mg IV  50100mg Q6h
or olanzapine 5mg PO
Dantrolene: 1mg/kg IV load 
1mg/kg QID IV or rpt to 10mg/kg
max in 24hrs