The triad of reduced consciousness, respiratory depression and pinpoint pupils
Expansion
The triad
- Reduced consciousness
- Respiratory depression, the cause of death
- Pinpoint (miotic) pupils
Plus bradycardia, hypotension, hypothermia and reduced bowel sounds.
Treatment: naloxone, titrated. In respiratory arrest give 400 micrograms and repeat; in a dependent patient with adequate ventilation, start at 40 to 100 micrograms and titrate to respiratory rate rather than consciousness, to avoid precipitating acute withdrawal and agitation.
“Titrate to breathing, not to waking.”
Naloxone lasts 20 to 90 minutes, which is shorter than methadone (up to 60 hours), modified release preparations and buprenorphine. The patient can therefore re-sedate after apparent recovery, so they need observation and often an infusion.
Other causes of pinpoint pupils: pontine haemorrhage, organophosphates, clonidine, and cholinergic agents.
Complications: aspiration, rhabdomyolysis and compartment syndrome from a long lie, non-cardiogenic pulmonary oedema, and hypoxic brain injury.
Take home naloxone should be offered to users and their contacts on discharge, alongside referral to drug services.