toxicology pgy 1+2 2013
TRANSCRIPT
![Page 1: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/1.jpg)
Dr Chris CresswellFACEM
Whanganui New Zealand
![Page 2: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/2.jpg)
The Bible
TOXINZ.com
![Page 3: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/3.jpg)
General approachResuscitate if neededRisk assessment – is what they have taken dangerous?Supportive Care and Monitoring
depending on your risk assessment Investigations
Everyone: Paracetamol level ECG
Other as indicatedDecontamination – very rareAntidotesEnhanced elimination - rareSeek and treat complicationsDisposition – usually psych. Psych does the psych risk
assessment for us.
![Page 4: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/4.jpg)
Toxinology
Critters rather than drugs/chemicals
We have one rare annoying, non-life threatening spider in NZ.
Katipo = red back – painful bite and sweating +/- back pain -> analgesia + antivenom.
Controversial whether antivenom actually works.
![Page 5: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/5.jpg)
Toxicology
Drugs and chemicals
Not going to cover them all!
![Page 6: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/6.jpg)
Toxidrome
What’s a toxidrome?What are some examples?
![Page 7: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/7.jpg)
Toxidrome
Clinical toxicological syndromeie you can examine a patient +/- look at their
ECG or other bedside tests and get a good idea of what they have taken
EgOpioidAnticholinergicCholinergic syndromeSerotonin syndromeNa channel blockade
![Page 8: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/8.jpg)
ToxidromesOpioid: resp depression, decr LOC, miosisAnticholinergic: hot as a hare, mad as a hatter, red as
a beet, dry as a bone eg daturaCholinergic syndrome eg organophosphate, nerve gas
SLUDGEM: salivation, lacrimation, urinarination, diarrhoea, GI upset, emesis, miosis + muscle spasm
Or DUMBELLS: diarrhoea, urination, miosis/muscle weakness, bronchorrhoea/bradycardia, emesis, lacrimation, salivation/sweating
Serotonin syndrome eg SSRI: sweating, agitation, increase muscle tone, fever
Na channel blockade eg tricyclic: hypotension, decr LOC, widened QRS
Rapidly alternating apnoea and coma eg GHB
![Page 9: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/9.jpg)
Tox examHRRRPupil size and reactivity and look for nystagmusArmpits for sweatReflexes and test for clonusTemp
ECGBSL
Labs: almost everyone gets a paracetamol level Cheap test. Treatment very efficacious.
![Page 10: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/10.jpg)
Some specific drugs / chemicals
Common or important ones.
![Page 11: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/11.jpg)
Paracetamol/acetominphenNB different units from UKCommonAlmost always reversible with antidoteHigh survival even from liver failureHow to you risk stratify and treat these
ingestions?What is the antidote?
![Page 12: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/12.jpg)
Paracetamol/Acetominophen Most common scenario: single ingestion, reasonable idea of time. < 10g or 200mg/kg ingested within 8 hours does not need
investigation Otherwise or unknown:
< 2 hours post ingestion of non-liquid and cooperative patient -> single dose activated charcoal.
< 4 hours post ingestion: wait and take blood for paracetamol level at 4 hours post ingestion. N-acetylcysteine (NAC) if over 1000µmol/L.
4-8 hours. Take level. NAC if over threshold on nomogram. 8-24 hours. Take level and start NAC. Stop treatment if under
treatment threshold. 24+ hours or unknown. Take level, VBG, LFT, glucose, INR,
renal function. Start NAC. Stop NAC if ALT normal. If liver failure d/w liver unit
![Page 13: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/13.jpg)
Paracetamol
![Page 14: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/14.jpg)
![Page 15: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/15.jpg)
Multiple dosesLook it up
![Page 16: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/16.jpg)
NACN-acetylcysteineVery safe and effectiveBoxes in ED with dose schedule written on them
3 different rates over 24 hoursFairly frequent anaphylactoid reaction
Eg erythema, urticaria, pruritis, hypotensionThought to be from histamine release rather than
true anaphylaxisIf mild reaction half rate +/- give IV antihistamineIf severe reaction. Stop infusion. Give IV
antihistamine +/- bronchodilators, fluids etc. Once asymptomatic for 1 hour restart infusion at ¼ rate and titrate up
![Page 17: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/17.jpg)
DispositionIn this hospital all patients requiring NAC get
admitted to ward under medical team. Inform psych of admission. They say they
will see patient before “medically cleared”
![Page 18: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/18.jpg)
SSRIsWhat do you need to know about these?
![Page 19: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/19.jpg)
SSRIsUsually no significant toxicityMain risk is serotonin syndrome
What is serotonin sydrome?
![Page 20: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/20.jpg)
Serotonin SyndromeRareExcess serotonin usually from over dose of SSRI
or combination of serotonergic agentsEg
SSRI, St John’s wortAntipsychoticsLithiumPethidineTramadolLSDEcstacy and other amphetamines
![Page 21: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/21.jpg)
Serotonin SyndromeSerotonergic drug +Mild: Tremor, anxiety, nauseaModerate: agitation and hyperreflexia and
clonusSevere: severe: fever, seizures, respiratory
failure, rhabdomyolysis, renal failure, DIC
![Page 22: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/22.jpg)
Serotonin syndromeManagement
Mild: observe for 4-6 hoursModerate: IV fluids, benzodiazepine, +/-
cyproheptadineSevere: cooling, IV benzodiazepine, IV fluid.
May need RSI
![Page 23: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/23.jpg)
So for all overdoses of serotonergic agent need ...Record
TemperatureTone Reflexes Clonus
![Page 24: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/24.jpg)
CCB and Beta Blocker
Cause ?
![Page 25: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/25.jpg)
CCB or Beta Blocker
Hypotension and bradycardiaMost beta blockers fairly benign
Exception: propranolol: Na channel blocking effect: manage as for tricyclic + Beta blocker
Calcium channel blockers: nasty
Treatment?
![Page 26: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/26.jpg)
Beta blocker + CCBResuscitate if required: ABCsRisk assessment: look up to see how toxic the dose
could be.Supportive care and monitoring: if moderate risk:
resus bay, IV access, cardiac monitoring, IV fluids, trial of atropine, calcium gluconate, pressors eg dopamine. If high risk likely to need intubation
Investigations: ECG, paracetamol level, lactate, glucose.
Decontamination: Whole bowel irrigation likely to be needed eg Polyethylene glycol via NG tube
![Page 27: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/27.jpg)
Beta blocker + CCB
Antidote/specific treatments: could call calcium an antidote to CCB, glucagon 5mg IV, high dose insulin 1 unit/kg then 1unit/kg/hour
Enhanced elimination: dialysis ineffective. Multidose activated charcoal may be effective for CCB.
Seek and treat complications: Likely to need ICU care. Monitor for MOF, rhabdo etc
![Page 28: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/28.jpg)
If all of the above wasn’t working what else could be done?
![Page 29: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/29.jpg)
Intraarterial balloon pumpBypass/ECMO
Most life threatening drug ingestions cause temporary CVS collapse – if we can support them through this the patient should do well
![Page 30: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/30.jpg)
SulphonylureasLife threateningAntidote?
![Page 31: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/31.jpg)
SulphonylureasAntidote: IV glucose then IV octreotide
![Page 32: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/32.jpg)
IronWhat’s important about ironWhat’s the antidote
![Page 33: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/33.jpg)
IronCan be life threatening and yet the patient is
asymptomatic, or has recoveredLook it upMost accidental ingestions not harmfulOver a threshold ingestion -> iron levels
usefulLow threshold for whole bowel irrigationAntidote: desferoxamine
![Page 34: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/34.jpg)
Digoxin
What are the 2 main types of toxicity?What are the classic signs and symptoms?What is the antidote?
![Page 35: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/35.jpg)
Digoxin2 main types of toxicity:
Acute ingestion – rare Chronic – usually due to dehydration/renal impairment
Consider this in any patient on digoxin who is unwell. Check ECG, K+ and digoxin level
Classic signs and symptoms Yellowed vision Nausea and vomiting Confusion Cardiac automaticity (ectopics or tachyarrythmia) and block
What is the antidote? Digoxin FAB fragments – “digibind” Expensive but cost effective
![Page 36: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/36.jpg)
Indications for Digoxin FAB
Hemodynamically unstable or life-threatening dysrhythmia,
Hyperkalemia > 6 mmol/L (6 mEq/L)Plasma digoxin level > 20 nmol/L (15.6
ng/mL) at 6 hours post-ingestionDigoxin level > 10 nmol/L (7.8 ng/mL) or
elevated digoxin level + renal impairment + symptoms in chronic toxicity
![Page 37: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/37.jpg)
Local anaesthetic
Eg femoral nerve block -> intraarterial
Classic signs?
![Page 38: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/38.jpg)
Local anaesthetic
Perioral tingling
Others: Visual disturbanceSeizureVT
Antidote?
![Page 39: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/39.jpg)
Local anaesthetic
Intralipid? Lipid sink? Cardiac fuel
![Page 40: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/40.jpg)
Tricyclic / propranalol
Na channel blockadeNasty
HypotensionDecr LOCSeizureDysrhythmias
Antidote?
![Page 41: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/41.jpg)
Na channel blockade"Prompt intubation, hyperventilation and
administration of administration of sodium bicarbonate at the first evidence of severe toxicity is life-saving"
![Page 42: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/42.jpg)
Na channel blockade from TCA
![Page 43: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/43.jpg)
Blue apnoeic patient dumped at the front door.
He has pin point pupils
How will you manage this patient?
![Page 44: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/44.jpg)
IV opioid toxicity
Lots of techniques
BVM ventilate
400mcg IM naloxone200mcg IN naloxone
![Page 45: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/45.jpg)
Oral opioid toxicity
If significant respiratory/LOC depression usually require naloxone infusion
Titrate IV nalaxone boluses to get just adequate reversal – don’t make the patient withdraw and run
Infusion of 2/3 of reversal dose/hour
![Page 46: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/46.jpg)
Rare but nasty
Theophylline -> vomiting +++ -> needs urgent dialysis
Ethylene glycol
![Page 47: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/47.jpg)
Neuroleptic Malignant SyndromeWhat is it?What do you do about it?
![Page 48: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/48.jpg)
Neuroleptic malignant syndromeRareUsually an idiosyncratic reaction to
standard/high doses of antispychotic rather than a result of overdosage.
Life threatening“Malignant Parkinson’s”
Parkinsonism + fever + autonomic instabilityDoesn’t have the agitation, hyperreflexia or
clonus of serotonin syndrome
![Page 49: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/49.jpg)
Neuroleptic malignant syndromeIf temp > 39.5 or rigidity compromising
ventilation -> RSICool to 38-39˚BenzodiazepinesTreat hypoglycaemiaBromocriptine +/or dantrolene
![Page 50: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/50.jpg)
“My child might have taken some of granny’s pills”
Try to work out what Granny is onDefault
Blood sugarBPECGIf abnormal or toxidrome: IV line and treat
empirically.If normal: Observe 12 hours. Discharge if BP and
BSL normal
![Page 51: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/51.jpg)
BenzodiazepinesAntidote – when do we use it?
![Page 52: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/52.jpg)
FlumazenilAntidote to benzosAlmost never usedOnly used if we caused the ODFor chronic benzo users or coingestion with a
proconvulsant (eg TCA) flumazenil may cause seizure
Benzos almost never need treatment or intubation
Recovery position, wait for them to wake up
![Page 53: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/53.jpg)
AlcoholAlmost never needs intubationRecovery position and observeLOC should improve hourly – if not consider
other diagnosis eg head injury
![Page 54: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/54.jpg)
Activated charcoalAlmost never usedLittle proof of efficacyHas killed people - aspiration
![Page 55: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/55.jpg)
Hydrofluoric acidNasty. 2% BSA exposure can kill
![Page 56: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/56.jpg)
WarfarinVitamin K and prothrombin complex
(prothrombinex)
![Page 57: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/57.jpg)
![Page 58: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/58.jpg)
InsulinGlucose + foodOccasionally 10% glucose infusion
![Page 59: Toxicology pgy 1+2 2013](https://reader038.vdocuments.mx/reader038/viewer/2022103016/5561f38cd8b42a2a488b46e3/html5/thumbnails/59.jpg)
CO and cyanideHigh flow oxygen then look it upCyanide ? Amyl nitrate, Sodium nitrite,
sodium thiosulphate (or dicobalt EDTA where available)