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526 Chapter 15: Overdose, poisoning and addiction

sweating.Increasedthirstcanbemarked,suchthatex- 5 Metabolic acidosis should be corrected with sodium
cessive water intake occurs, leading to hyponatraemia. bicarbonate intravenously, with rapid correction if
Occasionally transient gastrointestinal upset, confu- there is prolongation of the QT interval on ECG.

sion, dizziness and ataxia may occur. Mood effects are 6 Narrow complex tachycardias are treated with intra-
of euphoria, and ecstasy is unique in its ability to make venous β-blockers.
users feel ‘in tune’ with their surroundings and other 7 Hyperthermia is initially treated with sedation and
people, which is why it is so popular in the clubbing cooling, but if it is persistently >39˚C, ice baths and
world. dantrolene may be used.
Severe toxicity (usually an idiosyncratic response, 8 In severe liver failure seek advice from a liver unit, liver

rather than dose-related) includes cardiac arrhy- transplantation has been used.
thmias, hypotension and shock, hyponatraemia,
seizures, increasing confusion and loss of conscious-
ness.
A history should be taken of recent and previous
Overdose and poisoning
recreational drug use, including methods of admin-
istration, alcohol intake. A psychiatric and social his- Overview of acute poisoning
tory should be taken, as well as a medical history and
examination. Definition
Acute poisoning may result from accidental self-
ingestion, deliberate self-harm or medical error.
Complications
Deaths: These appear to be due to cardiac arrhythmias,
Incidence/prevalence
fulminant liver failure and neuroleptic malignant syn-
Common presentation to A&E, commonest cause of
drome, which may cause acute renal failure, dissemi-
medical admission of teenagers.
nated intravascular coagulation and metabolic acidosis.
Neuropsychiatric complications include memory and
concentration loss, insomnia, hallucinations and flash- Age
backs. Any,accidentalingestionmostcommoninage2–3years.

Investigations Sex
In all cases, ECG, U&Es, LFTS and creatine kinase (CK) Deliberate self-harm is more common in females.
shouldbeperformed.Inseverecasesacoagulationscreen
and arterial blood gases should be performed. Aetiology
Many different substances are involved in poisoning, es-
pecially in children (see Table 15.1).
Management
In severe toxicity, initial management includes ensuring
aclear airway, and ventilation if needed. Clinical features
1 All patients should have cardiac, pulse, blood pressure Acutepoisoningshouldbeconsideredinanypatientpre-
and temperature monitoring. senting with altered levels of consciousness; however, the
2 Diazepam for agitation, anxiety, significant hyperten- vast majority of patients who present are conscious. The
sion and seizures. patient or carers may be able to give a history and bring
3 Continued hypertension is treated with intravenous the containers or tablets. A full physical examination
glyceryl trinitrate, but in refractory hypertension con- should be made.
tact the NPIS. Central nervous system: Impaired consciousness, this
4 Symptomatic hyponatraemia is usually treated with can rapidly be assessed using the AVPU (Alert, re-
water restriction; however, in coexisting hypotension sponds to Voice, responds to Pain, Unresponsive) sys-
normal saline infusion may be required. temormore formally using the Glasgow Coma scale.