Approach to the poisoned patient
Channel: 2minuteEM
Date: 2020-04-21

#FOAMed 
emergency medicine 
poisoning 
toxicology 
2minuteem

Emergency medicine tips in 2 minutes.  Approach to the poisoned patient.  For anyone interested in emergency medicine!

Additional slide information

1. Listen to your paramedics

SBAR=Situation, Background, Assessment, Recommendation.  SBAR is a decent tool if you want an aide-memoire to help when you're referring patients too: 

https://learn.nes.nhs.scot/3408/quality-improvement-zone/qi-tools/sbar

The PRF is soooo useful - try to read it for every patient you see.  A low BM may suggest gliclazide overdose for example.  A high temperature may suggest serotonin syndrome, or perhaps another cause for the patient's presentation such as sepsis.

2. Talk to your patient

What might a patient have taken if they appear intoxicated but without evidence of ethanol ingestion? 

http://www.emdocs.net/the-unhappy-drunk-toxic-alcohols/ 

(Try and commit the metabolism pathway to memory - it's tricky - I still haven't quite managed!)

House fire, smell of bitter almonds and high lactate? Think CYANIDE toxicity...watch this excellent "EM in 5" video:

https://emin5.com/2015/05/04/cyanide-toxicity/ 

3. Get your venous blood gas early doors

Venous blood gases have changed the way I practise EM over the last few years.  They give you an early "snapshot" of the patient's metabolic picture.  Things to look out for would be: profound metabolic acidaemia (unhappy heart - dysrhythmias); potassium level; glucose level; COHb and MetHb levels; and importantly, BASE EXCESS and anion gap.  

Work out if the patient has HAGMA (high anion gap metabolic acidosis) then work through your MUDPILES mnemonic if so:

https://en.wikipedia.org/wiki/High_anion_gap_metabolic_acidosis

4. One ECG begets another...

Very wise words.  The biggest thing sticking out for me here is tricyclic antidepressant poisoning (e.g. amitriptyline) - this always gets me concerned as an ED care provider.  You need repeat and often multiple ECGs to see if the QRS is widening (sodium channel blockade)...and don't forget the QT interval.  There are many "cardiotoxic" drugs out there - more than you realise - but TOXBASE will keep you right.  (There is even a QT nomogram on there which assesses your patient's risk of Torsade de Pointes.)

5. Pattern recognise.

Paracetamol does indeed have a silent toxidrome - that's why we check levels so often.  Some ED care providers check it on every "tox" patient; some don't, depending on the patient's story, recollection and conscious level.  

Anticholinergic toxidrome: SLUDGE BM is your mnemonic!

https://twitter.com/2minuteEM/status/1095755815326269443

The hot, agitated patient with ankle clonus that doesn't seem to stop (!) should make you think about serotonin syndrome (check the link below but it's just the simple Hunter diagnostic criteria that you want):

https://learned.rocks/omws-resourced/2016/11/4/serotonin-syndrome

6. Use Toxbase!

Ok - I cannot overstate how essential Toxbase is to your practice as an ED care provider.  The Toxbase usernames and passwords are shrouded in mystery and only known to a few in the ED - seek and you shall find (try the regs first!)

7. Plan ahead

Planning ahead is what EM is all about so you should be used to this - I used to get told "think three shots ahead" when I had a brief dalliance with snooker, and this what you need to do.  Toxbase has sensible advice which will keep you right.

8. Assess flight risk

Your department may have "ED mental health assessment" forms, which allow you a physical description of your patient and documentation of their mental state, in case they do abscond.  Try and do everything to mitigate this outcome: talk to your patient; keep them informed; do they need a cup of tea?; have their cubicle opposite the nurses' station.

If the patient refuses treatment or escalates their behaviour, then you may need to give your patient emergency treatment under common law, if they lack capacity and if it is in their best interests.  This can be done to sedate a combative patient; to facilitate taking bloods and site an IV cannula; or to administer acetylcysteine in paracetamol poisoning.  This should only be done as an emergency and/or last resort measure after trying everything else.  The patient's dignity must be respected at all times.  (NOTE that ED practices may differ according to your local protocols and mental health law structure.  My practice is based in Scotland.) 

If you got this far, thanks for reading and watching!