176 Tox icolog y
SPECIFIC POISONS
2 Administer norma l sa line to maintain a norma l blood pressure (BP).
3 Gastrointestinal decontamination is rarely necessary unless there is
co-ingestion or the patient is deeply unconscious, in which case protect the
air way f irst by endotrachea l intubation.
4 Admit the patient to the ED observation unit overnight, followed by sub-
sequent psychiatric evaluation.
5 The use of f lumazenil, a specific benzodiazepine receptor antagonist, is
controversial. It is rarely if ever indicated, and must be discussed with the
senior ED doctor.
(i) Flumazenil may induce VT, elevate intracranial pressure,
precipitate benzodiazepine withdrawal in chronic abusers, and
may invoke seizures, particularly with co-ingestion of TCAs.
(ii) Potential roles for flumazenil are thus restricted to:
(a) reversal of excessive benzodiazepine sedative effect following
procedural sedation
(b) reversal of respiratory depression and coma in a pure
benzodiazepine overdose, to prevent the need for intubation.
The difficulty is knowing when no other drugs were ingested.
Opioids
DIAGNOSIS
1 Opioid drugs include opium alkaloids such as morphine and codeine; semi-
synthetic opioids such as heroin (diamorphine) and oxycodone and fully
synthetic opioids such as pethidine and methadone.
2 Opioids produce euphoria, pinpoint pupils, sedation, respiratory depression
and apnoea with increasing doses.
3 Other complications of opioid intoxication include hypotension, convul-
sions, non-cardiogenic pulmonary oedema and compartment syndrome
from prolonged immobility.
4 Perform a thorough examination to evaluate potential complications, and to
exclude alternative causes of an altered mental state with bradypnoea such as
sepsis, neurotrauma, stroke and metabolic disease (see p. 80).
5 Send bloods for U&Es, blood sugar and serum paracetamol level. Perform an
ECG.
MANAGEMENT
1 Commence supportive care wit h ox ygen and assisted ventilation.
2 Give naloxone 0.1–0.4 mg i.v. as a bolus or in 0.1 mg increments. Carefully
titrate response to achieve improved airway control and adequate ventila-
tion, without precipitating an acute agitated withdrawal state.