Emergency Medicine

Environmental Emergencies 205

HEAT, COLD AND DROWNING

(a) arrange a senior doctor to perform endotracheal intubation

and ventilation with muscle paralysis, to protect the airway

and prevent further muscle-generated heat production

leading to multiple organ failure, neurological injury and

death.

3 Neuroleptic malignant syndrome
(i) Give bromocriptine (a dopamine agonist) orally or via a
nasogastric tube. Start at 2.5 mg 8-hourly, increasing to 5 mg
every 4 h (maximum 30 mg/day) in moderate to severe cases.

4 Serotonin syndrome
(i) Give bromocriptine (a dopamine agonist) orally or via a
nasogastric tube. Start at 2.5 mg 8-hourly, increasing to 5 mg
every 4 h (30 mg/day) in moderate to severe cases.
(ii) Add midazolam 0.05–0.1 mg/kg i.v., or diazepam 0.1–0.2 mg/kg
i.v. titrated to achieve gentle sedation.

5 Malignant hyperthermia syndrome
(i) Administer dantrolene 1 mg/kg i.v. for severe muscle rigidity and
hyperthermia. Further doses of 1–2.5 mg/kg (up to a maximum
of 10 mg/kg/24 h) may be required.

Hypothermia

This is present when the core temperature drops to <35°C (95°F), and occurs
when heat loss exceeds the body’s ability to produce and conserve heat.

Mild hypothermia is classified as 32–35°C (89.6–95°F), moderate hypothermia as
30–32°C (86–89.6°F), and severe hypothermia as <30°C (86°F).

DIAGNOSIS

1 Hypothermia is predisposed by the following:
(i) Exposure to low air temperatures, particularly with wind and
rain.
(ii) Exposure in cold water.
(iii) Unconscious patient, or patients who have taken sedative drugs,
especially alcohol.
(iv) Babies or the elderly with intercurrent illness, e.g. stroke,
pneumonia, diabetic ketoacidosis (DKA).
(v) Endocrine disorders, such as myxoedema or hypopituitary coma
(rare).

2 Clinical manifestations include:
(i) Mild hypothermia: poor judgement, lethargy, ataxia, shivering
and tachypnoea.
(ii) Moderate hypothermia: bradycardia, hypotension, bradypnoea,
and confusion. Shivering is absent.