Emergency Medicine

Environmental Emergencies 203

HEAT, COLD AND DROWNING

(vi) Gain i.v. access and send blood for full blood count (FBC),

coagulation profile, urea and electrolytes (U&Es), blood sugar,

liver function tests (LFTs), creatinine kinase (CK) and lactate.

(vii) Check an arterial blood gas (ABG). Attach an electrocardiographic

(ECG) monitor and pulse oximeter to the patient.

MANAGEMENT

1 Heat cramps
(i) Rest in a cool environment, and replace fluid orally with added
salt or give 1 L normal saline iv.
(ii) The patient is usually able to go home.

2 Heat exhaustion
(i) Rest in a cool environment and give up to 3 L cooled normal
saline i.v.
(ii) Cool the patient with tepid sponging and fanning.
(iii) Admit for observation, particularly when elderly or if orthostatic
hypotension persists.

3 Heat stroke
(i) Give oxygen and aim for an oxygen saturation above 94%. Call
the senior emergency department (ED) doctor for help, and
arrange for endotracheal intubation for airway protection.
(ii) Commence urgent cooling by tepid sponging, fans and cold
packs to the groin and axillae until the temperature is <38.5°C
(a) avoid excessive shivering, but do not use chlorpromazine
25 mg i.v. to suppress this due to its multiple side effects
(b) antipyretics such as aspirin and paracetamol are also not
indicated.
(iii) Give 1 L cooled normal saline over 20 min, then give fluid
according to the blood pressure, serum sodium level and urine
output.
(iv) Give midazolam 0.05–0.1 mg/kg up to 10 mg i.v., diazepam
0.1–0.2 mg/kg up to 20 mg i.v., or lorazepam 0.07 mg/kg up to
4 mg i.v. for seizures and/or agitation.
(v) Monitor for complications such as hypoglycaemia and give 50%
dextrose 50 mL.
(vi) Give 8.4% sodium bicarbonate 50 mL plus 20% mannitol
0.5–1.0 g/kg (2.5–5 mL/kg) for rhabdomyolysis, and maintain a
urinary output of 1–2 mL/kg per h.
(vii) Admit the patient to the intensive care unit (ICU) for sedation,
intubation and neuromuscular blockade.