Emergency Medicine

204 Environmental Emergencies

HEAT, COLD AND DROWNING

Other hyperthermia-related illness

Hyperthermia-related syndromes may be associated with specific drug adminis-

tration such as anticholinergic agents, serotonin agonists, dopamine antagonists

and inhalational anaesthetics.

DIAGNOSIS

1 Neuroleptic malignant syndrome

(i) Rare but potentially lethal syndrome complicating the use

of dopamine antagonist neuroleptic medication such as

antipsychotic agents (e.g. chlorpromazine, haloperidol) and some

antiemetics (metoclopramide).

(ii) It is associated with development of muscle rigidity,

bradyreflexia, bradykinesia, altered mental status, extrapyramidal

symptoms and hyperthermia.

2 Serotonin syndrome

(i) This is a clinical manifestation of excessive stimulation of

serotonin receptors in the central nervous system (CNS).

(ii) It follows drug combinations with selective serotonin reuptake

inhibitors (SSRIs), monoamine-uptake inhibitors, analgesics such

as fentanyl or tramadol, antiemetics such as ondansetron, and

stimulants such as amphetamine or cocaine.

(iii) It has a spectrum of severity ranging from agitation and

hyperreflexia through to generalized rigidity, myoclonus,

autonomic instability, mental status changes and hyperthermia.

3 Malignant hyperthermia syndrome

(i) A rare genetic disorder that develops during or after receiving an

inhalational anaesthetic or suxamethonium.

(ii) Characterized by muscular rigidity, hypercapnoea, tachycardia,

hypertension, mottled diaphoretic skin and agitation.

4 Gain i.v. access and send urgent bloods including FBC, coagulation profile,

electrolyte and liver function tests (ELFTs), CK and lactate. Add blood

cultures if sepsis is suspected.

5 Check an ABG, perform an ECG, and send a midstream urine (MSU)

sample.

MANAGEMENT

1 Give high f low ox ygen and commence i.v. norma l sa line.

2 Check the temperature and commence supportive care.

(i) Temperature >38.5° is an indication for continuous core-

temperature monitoring.

(ii) Temperature >39.5° with an altered mental status is an

emergency: