Adult Medical Emergency Handbook - Scottish Intensive Care Society

conscious level.
• Correct electrolyte or acid-base disturbance, ensure adequate hydration.
• Perform ECG and monitor cardiac rhythm.
• If QRS >120 ms after TCA overdose, administer IV 8.4% sodium
bicarbonate 50 ml (=50 mmol) via central or large peripheral vein,
even in the absence of acidosis, to reduce risk of arrhythmia and
seizure. Repeat as necessary.
• Arrhythmias are best treated by correction of hypoxia and acidosis
(metabolic and respiratory). Torsade de pointes should be treated
with IV magnesium sulphate 8-10 mmol over 1-2 minutes. Consult
TOXBASE® or contact NPIS for further advice.
• Treat seizures with IV lorazepam (2-4 mg) or diazepam 10-20mg;
repeated doses may be required.
• Serotonin syndrome may occur after ingestion of 2 or more
drugs with serotonergic effects e.g. TCAs, SSRIs, monoamine
oxidase inhibitors, tramadol. Features include alteration of mental
status, neuromuscular hyperactivity and autonomic instability.
If suspected, monitor temperature and check serum creatinine
kinase (CK). Discuss management with NPIS.
OPIOIDS
For example codeine, diamorphine, dihydrocodeine, fentanyl,
methadone, morphine, pethidine, tramadol.
Features
Reduced conscious level, respiratory depression, pinpoint pupils and
hypotension. (N.B. opioids and their active metabolites accumulate in
patients with renal impairment: opioid toxicity should be suspected
in any patient with unexplained type-2 respiratory failure)
Management
• ABCDE as Chapter 2.
• Monitor respiratory rate and ensure adequate airway and support
ventilation.
• If reduced conscious level or respiratory depression, then
administer IV naloxone 0.4-2.0 mg: repeat the dose if inadequate
response after 2 minutes.
• Naloxone (Narcan®) is a competitive antagonist and large doses
(>4 mg = 10 ampoules) may be required in severe cases.
• Naloxone can be administered by the IM route if IV access is not
possible, or if the patient is threatening to self-discharge when its
effects might be more prolonged.
266 adult medical emergencies handbook | NHS LOTHIAN: UNIVERSITY HOSPITALS DIVISION | 2009/11