Term
Organophosphate / Carbemate Poisoning
Risk assessment
Clinical Features
Rx |
|
Definition
Risk Asessment
-Any intentional Exposure considered life threatening
-Any paediatric exposure life treatening
-Inadvertant occupational exposure usually not life threatening.
-Onset of effects up to 12 hours.
-Carbemates usually less toxic than organophosphates (don't cause aging of ACHE bond)
Clinical - Inactivation of ACH esterase - Cholinergic syndrome. Initially reversible but ageing of bond - irreversible
Muscarinic effects (DUMBBBELS / the killer B's
Diarrhoea, urination, miosis, bradycardia, bronchorhoea, bronchoconstriction, emesis, lacrimation, salivation.
Nicotinic - tachycardia, hypertension, sweating, fasciculation, muscle weakness.
CNS- Agitation, Coma, Seizures.
Resp - Chemical pneumonitis with aspiration
Rx
A/ B- Risk of obtundation / Aspiration / Respiratory failure (bronchoconstriction / bronchorhoea)
Definative airway management / ventilation early (esp if poor response to atropine)
C- Haemoynamic instability
Bradycardia
Significant fluid losses - hypovoalemia
1L N/S and reasess
Atropine if Bradycardia, or sinificant muscarinic features.
Escalating doses -often high (1.2g and double every 5 mins)
D- Anticipate Seizures and treat with IV midazolam
Exclude hypoglycemia.
Supportive care / monitoring
-Analgesia / Sedation if intubated)
IDC and monitor urine output , ongoing fluid losses - replace
Investigations - Screening 12 lead / paracetamol level
Specific - Red Cell / Plasma ACH esterase levels.
Decontamination - Activated charcoal useless.
Remove clothes/ Wash skin
Antidotes: Atropine escalating doses - Endpoints HD stable, Dry airway secretions
- Pralidoxime - 2g IV stat then infusion. (more important for OP than carbemates)
No enhanced elimination
Disposition
-Observe 12 hours post any deliberate exposure / any child exposure
-Observe 24 hours post xime rx
-Arrange follow up to detect delayed effects ((intermediate sx delayed paralysis -2-4 days, delayed polyneuropathy / neuropsychiatric sequellae, |
|
|
Term
'Two pills can kill'
High Risk Toddler ingestions |
|
Definition
AMphetamines
Ca2+ blockers
Diltiazem, Verapamil
Opioids
Tricyclic Antidepressants
Chloroquine, hydroxychloroquine
B-Blocker (especially propranolol)
Sulphonylureas
Theophyline
Management of toddler who ingests unidentified tablet aimed at observation to detect these serious ingestions
Essentially admit for observation at least 12 hour and don't discharge at night.
ECG
BSL at admission and discharge. |
|
|
Term
Ethylene Glycol Poisoning / Methanol Poisoning
Toxic Mechanism
Clinical features
Risk assessment
RX |
|
Definition
Toxic mechanism
Ethylene glycol --> picture similar to alcohol intoxication
Severe Toxicity from metabolites (glyoxylic acid / oxalic acid)
Causes - HAGMA, Calcium oxalate deposition in tissues - kidneys (ARF)myocardium, muscles and brain.
Hypocaclemia.
-Dyspnoea / Tachypnoea,
-Hypertension / tachycardia progressing to Shock
-Flank pain and oliguria (ARF)
-Late cranial nerve palsies.
Methanol - Acute ETOH like intoxication. Delayed ALOC --> Seizures / obtundation. Tachypnoea (HAGMA), Visual disturbance.
-ALOC, seizures,
Risk asessment > 1ml / kg potentially lethal (most deliberate ingestions potentially lethal)EG
Methanol 0.5 ml / kg
Rx
RESUS
-A/B: Note respiratory compensation for metabolic acidosis. If RSI required ensure to continue hyperventilation +/- Bicarbonate prior to avoid exacerbating acidosis.
-D: Seek and treat hypoglycemia.
Anticipate seizures - treat with IV benzo.
Supportive -
Detect and correct hypoglycemia, hypomagnesemia, hyperkalemia . Correct hypocalcemia only if refractory seizures / long QT (EG).
IDC / Monitor fluid balance / Urine output.
Ix - Screening ECG / paracetamol
Blood Gas - HAGMA, High Osmolar gap
Ethanol level
Urine microscopy (? Ca oxalate crystals)
Ethylene glycol levels generally unavailable. Methanol levels often delayed.
Enhanced Elimination
-Haemodialysis
EG: *Indicated for hx of large ingestion and high osmolar gap
*HAGMA pH <7.25
*ARF
Methanol HD indication
-pH < 7.3
-Visual Symptoms
-Renal Failure
-Deterioration of vitals despite supportive care
Antidotes - Fomepizole / ETOH
Competitively inhibit alcohol dehydrogenase. (Temporising measure pending Haemodialysis)
Disposition: Adult pts Well, negative breath test for ETOH and normal bicarb 4 hours post accidental ingestion fit for discharge
Admit all symptomatic patients. |
|
|
Term
amphetamine intoxication
Clinical features
Complications
Rx |
|
Definition
Sympathomimetic
CNS - Euphoria, agitation, psychosis
CVS - HTN, Tachycardia
Metabolic (SIADH / Hyponatremia with MDMA)
Peripheral Sympathomimetic
Midriasis, sweating, tremor
Complications - Psychosis, SAH, ACS, Aortic / coronary dissection, APO,
Rhabdomyolysis / ARF
ischemic colitis.
Rx: Supportive care usually adequate
-Control HTN with Titrated benzodiazapines
If refractory hypertension- phentolamine / GTN.
B-Blockers are contraindicated! Unopposed alpha agonism. |
|
|
Term
Superwarfarins
(eg Brodifacoum)
Risk Asessment
Clinical features
Rx |
|
Definition
0.1mg / kg (approx 3 50g pellet boxes in adult will cause Coagulopathy - sometimes delayed. Prolonged, needing long term massive Vit K therapy. Normal INR @ 48 hours excludes intoxication.
Rx: Major bleeding - FFP 15 ml / kg, prothrombinex 50u / kg / Vit K 10mg IV.
Activated charcoal to massive ingestions < 12 hours old.
Stable pts need serial INR and titrated Vit K PO daily for INR < 4.
Don't initiate Vit K prophylactically (ie to normal INR - delays onset of toxicity) |
|
|
Term
Arsenic Poisoning
Clinical Features
Rx |
|
Definition
-Severe acute gastroenteritis followed by progressive multi-organ failure
(Arsenic inhibits cellular respiration)
-Hypersalivation with garlic smell
Encephalopathy, seizures
Cardiomyopathy / dysrythmias
Survivors subseqiently exhibit Bone marrow depression over weeks and alopecia and an ascending polyneuropathy.
Rx - Meticulous supportive care
Hypovolemia from gastroenteritis is immediate life threat - Aggressive resuscitation.
Decontamination - Whole bowel irrigation (activated charcoal doesn't work)
Urinary arsenic levels useful in confirming diagnosis.
Antidote: Chelation Therapy - Succimer PO or Dimercaprol IM.
Disposition - Clinically well 12 hours post ingestion without GI symptoms are not poisoned and can be discharged. |
|
|
Term
B Blockers
Risk assessment
Clinical effects
Rx |
|
Definition
Most B- Blockers cause minor toxicity only. Exceptions are propranolol with Na+ blocking effects and sotalol with K + blocking effects.
Clinically - Hypotension / BRadycardia
QRS prolongation (propranolol)
QT prolongation sotalol --> Torsades)
CNS - ALOC / Seizures (propranolol)
Hyper / hypoglycemia
Hyperkalemia
Bronchospasm
Pulmonary oedema.
Rx
Resus
-Prepare for Intubation, hyperventilation and Bicarb therapy for propranolol (Like TCA)
- Hypotension / Bradycardia
-IVT
-Atropine 10 -30 mcg / kg
-Isoprenaline 0.1mcg / kg / min + titrate
-Pacing likely ineffective
-High dose insulin therapy
Wide QRS (propranolol) --> Bicarb
Long QT --> Torsades (Sotalol_
-Mg2+
-Isoprenaline
Overdrive pacing
Decontamination - Not usually useful
Antidotes - As above
Consider intralipid (1-1.5 ml / kg + repeat 5 mins)for propranolol. |
|
|
Term
Baclofen OD
Risk asessment
Clinical Features
MAnagement |
|
Definition
->200mg in adults expected to cause coma, respiratory depression and seizures.
-Routine supportive care ensures good outcome.
Clinical features
GABA analogue
CNS depression
Paradoxical seizures (pre-synaptic mediation)
Respiratory depression
'Pseudo Brain death with absent brainstem reflexes'
-Fixed dilated pulips , Doll's eyes, loss of corneal reflex, profound hypotonia.
Rx
RESUS - Coma / respiratory depression -- RSI
Hypotension usually fluid responsive
-Treat Seizures with titrated benzodiazapine
-Routine Supportive Care.
No decontamination, Antidotes or enhanced elimination. |
|
|
Term
Barbituate OD
Clinical Features
Risk assessment
Management |
|
Definition
Profound CNS depression / respiratory depression and hypotension - within minutes of IV admin of Thiopentone (eg medico's and vets) or within 1-2 hours of PO administration of Phenobarbitone.
Coma can be profound and mimic brain death.
Risk asessment: Ingestion > 8mg / kg likely toxic
Self IV admin likely rapidly lethal.
Rx- Resus
-Immediate life threat = Coma, respiratory depression--> Early intubation.
Hypotension --> IVT, Vasopressors / ionotropes.
Routine Supportive Care
Ix - Screening paracetamol / ECG / BSL.
-phenobarbitone asseys routinely available --> useful to follow enhanced elimination,
Decontamination --> Activated charcoal once airway secure.
Enhanced elimination --> Multi dose activated charcoal and haemodialysis if phenobarb level > 100 mmol / L. (Reduced ICU ventilator time)
No antidote
Disposition - IF asymptomatic 6 hours post ingestion can discharge. |
|
|
Term
Bupropion Overdose
Risk Asessment
Management |
|
Definition
Bupropion is a monocyclic antidepressant with similar toxicity profile to Tricyclic antidepressants but a particularly high risk of seizures with ANY overdose.
>9g Risk of cardiovascular complications (prolonged QRS and QT tachyrhythmias and collapse)
MAnagement
-As per TCAs (I+ V + hyperventilation + Na HCO3 for broad complex tachyarrythmias.
Early RSI if Hx + clinical progress consistent with > 9g ingestion
-Consider prophylactic benzodiazapines
-Treat Seizures with Titrated benzodiazapines
-Routine Supportive Care.
Ix: ECG (QT + QRS prolongation , BSL, para.
VBG
Decontamination - Activated charcoal only after definitive airway.
No enhanced elimination / antidotes.
Disposition: Observe 24 hours - Hig risk seizures. Cardiotoxicity warrents ICU. |
|
|
Term
Calcium Channel Blocker OD
Risk Assessment
Management |
|
Definition
-Verapamil and Diltiazem cause life threatening Cardiovascular collapse with > 10 tablets of XR preperations.
Dihydropyridine CCBs rarely cause significant toxicity.
Management
RESUS
Immediate life threat is progressive bradycardia and hypotension + Conduction disturbance
-If hx significant ingestion and signs early toxicity (ie SBP<90) do not delay RSI.
-Progressive approch to hypotension / bradycadia.
-IV N/S - 1L + repeat.
-Calcium Cloride 10% 20 mls / Calcium Gluconate 10% 60 mls. + repeat up to 3 times (temporising)
-Atropine 0.6mg Q 3min up to 3mg
-Catecholamine - (My preference = adrenaline 0.1mcg / kg / min + titrate)
-High dose insulin therapy
-Na + HCO3 (correct any metabolic acidosis)
-Pacing (unlikely effective)
Consider - bypass / IABP / intralipid.
Routine Supportive care.
Ix - ECG, para, BSL
UEC (esp Ca2+)
Blood gas - lactate / pH
Decontamination - Activated charcoal to cooperative patients OR once airway secure + whole bowel irrigation
No enhanced elimination
Antidotes as above.
Disposition - well + normal ECG @ 4 hours, (standard preps) 16 hours (XR preps) OK for discharge. |
|
|
Term
Carbemazapine OD
Clinical Features
Risk Asessment
Rx |
|
Definition
. Blocks inactivated Na+ channels, NA reuptake inhibition. antimuscarinic, antinicotinic and NMDA antagonism.
Clinically
CNS - Nystagmus, dedation, dysarthria, mydriasis, myoclonus progressing to Coma and eizures.
-Anticholinergic effects
Extreme doses --> Cardiotoxicity, (wide QRS)+ VF, VT, asystole
>50mg / kg --> risk of Coma and cardiotoxicity.
Rx
Routine resus and supportive Care
-Cardiotoxicity Rx with Bicarb
-Seizures with benzodiazapines
Ix- screening: ECG (wide QRS), paracetamol, BSL
Carbamazepine level available and useful for monitoring progress of elimination in coma.
Decotamination - Charcoal post ETT.
Enhanced elimination. (unproven but consider MDAC / Haemodialysis for severe toxicity)
Disposition. Well without anticholinergic effects, normal ECG, no sedation @ 8 hours can discharge. |
|
|
Term
CO poisoning
Clinical Features
Rx
Pregnancy considerations. |
|
Definition
-Tissue hypoxia underlying mechanism
-Neurological - Headache / nausea, Confusion, drowsiness, , seizure, Coma.
Long term neuropsyciatric sequelae common.
Cardivascular - Tachycardia, , Ischemia, Hypotension, dysrythmia.
Metabolic - Lactic acidosis.
Respiratory - Non cardiogenic pulmonary oedema
Potential for multi-organ failure and death.
-Management is Routine supportive care and 100% oxygen. Until asymptomatic or for 24 hours if pregnant.
Poor evidence for hyperbaric therapy but may be an option (esp for pregnant patients).
-Ix- CO levels corrorlate poorly with intoxication unless performed immediately after cessation of exposure.
CHECK HCG.
Pregnancy - Foetal Hb binds CO more readily --> at high risk of injury. |
|
|
Term
Chloroquine, Hydroxychloroquine overdose
Toxic Mechanism.
Management |
|
Definition
Toxic mechanism is similar to TCAs with Na+_ channel blocking effects.
Neurotoxicity with Coma and seizures
Cardiotoxicity - QRS widening / long QT, arrythmias, varying degree of heart blocks + direct myocardial depression.
Also causes K+ uptake --> hypokalemia
10mg / kg potentially toxic, 30mg / kg usually severe. Narrow therapeutic window.
Rx - As per TCA, early intubation for CNS depression
Hyperventilation / Na+ HCO3 for Cardiotoxicity
-Cautious K+ replacemnt (body stores not low)
-Benzo's for seizures, |
|
|
Term
Chloral Hydrate OD
-Toxicity
-Rx |
|
Definition
(Obsolete sedative - still available for paediatrics)
-Sedation, + cardiotoxicity (hypotension and tachydysrythmias (SVT, AF, VT thought to be secondary to catecholamine sensitisation)
Rx - Routine RESUS and supportive Care BUT
-B- Blockers (0.1mg/ kg metoprolol IV,+ repeat @ 5 mins) +/- esmolol infusion. For tachydysrythmias including VT
-Catecholamines contraindicated for hypotension - Rx with IVT.
-Large ingestions can be corrosive --> consider endoscopy. |
|
|
Term
Cocaine OD
Clinical Features
Management |
|
Definition
Sympathomimetic and Local anaesthetic effects.
-CVS- HTN, Tachycardia, coronary spasm, arrythmias and conduction disorders, long QT.
CNS - Euphoria, agitation, psychosis, seizures.
Peripheral sympathomimetic
-Hyperthermia,mydriasis, sweating, tremor
Complications
-Ischemia, dissection, SAH / ICH, Ischemic colitis.
Management
-Routine Resus and supportive Care - Titrated Benzodiazapines for Agitation and hypertension.
Life threats
- VT - NaHCO3, defibrillation, refractory VT lignocaine1.5mg / kg + infusion.
-Seizures - BEnzodiazapines
-Hypertensive crisis
1: Benzodiazapines
if refractory - phentolamine, GTN.
B - Blockers are contraindicated!
-Hyperthermia - T >38.5 --> core temp monitoring, T>39.5 needs urgent cooling.
Seek and treat complications based on Hx / Exam (Eg: Consider neuroimaging if headache, serial ECGs / TNI for chest pain)
Decontamination / Enhanced elimination not useful (except charcoal for body packers)
Disposition - Well and asymotomatic @ 4 hours with normal ECG can be discharged. |
|
|
Term
Colchicine OD
Clinical Features
Risk Asessment
Rx |
|
Definition
Microtubule inhibition.
GI symptoms - vomiting diarrhoea, abdominal pain, massive fluid losses. (2-24 hours)
2-7 days - Pancytopenia, ARDS, Renal Failure, cardiac arrythmias, risk of sudden death
> 7 days - Rebound leukocytosis and transient alopecia (survival likely from this point on)
> 0.5mg / kg causes severe toxxicity
Admit all Colchicine OD's!
Management
-Usual resus and supportive care anticipate deterioration. Institute invasive monitoring.
-Initial presentation may be hypovolemic shock.
-Ix- routine screening
Blood gas, electrolytes, blood film, coags to monitor complications.
No levels available.
Decontamination - Activated charcoal to all ingestions > 0.5mg / kg.
Elimination - >??MDAC not routine
Antidote - Colchicine AB exists but not available. |
|
|
Term
Cyanide Toxicity
Mechanism / Clinical Features
Rx |
|
Definition
-Inhibits cellular respiration, stimulates NMDA release --> Seizures
Clinical Features
Early - Nausea, vomiting, headache , dyspnoea, tachycardia, LACTIC ACIDOSIS
Late - Seizures,COMA, bradycardia / hypotension.
-Suspect in Smoke inhalation (particularly with lactic acidosis without severe burns)
Rx:
Resus / Supportive care along conventional lines.
Ix - Routine screening
VBG (lactic acidosis)
Cyanide levels available but delayed and don't alter acute management
Decontamination - Remove clothes, wash skin.
Enhanced Elimination - None
Antidotes - Hydroxocobalamin (preferred),thiosulfate, dicobolt edetate |
|
|
Term
Digoxin- Acute OD
-Clinical Features
-Risk asessment
-Rx
-Indications for Digibind |
|
Definition
-Blocks Na+ / K+ ATPase --> reduced Na+ gradient, increased intracellular Calcium. Serum hyperkalemia. Also increased vagal tone -->reduced SA node / AV node conduction.
Nausea and vomiting @ 2-4 hours, peak effect @ 6 hours.
-GI - nausea / vomiting / abdo pain
CVS- Bradycardia, 123 degree block, AF with Slow vent rate
Increased ventricular automaticity - Vent ectopics, VT.
Hypotension and cardiovascular collapse.
CNS: Lethargy, confusion, Delerium.
Risk assessment: >10mg adult = severe toxicity
Ix- ECG - monitor for arrythmia / blocks, BSL, paracetamol
UEG - Renal function, hyperkalemia important predicter of severe toxicity
Dig level -confirm diagnosis and provide indication for digibind.
Rx -Resus / supportive care as usual
-Immediate threats -
Cardiac arrest - Standard measures futile without Digibind- ALS until 20 ampules digibind administered - continue CPR 30mins after admin.
If digibind not immediately available, temporarily address these issues.
-Hyperkalemia -
NO CALCIUM
NaHCO3 / insulin / dextrose
AV block
-Atropine 0.6mg + repeat up to 3mg
Pacing rarely effective
Ventricular arrythmias - Lignocaine 1mg / kg / 2mins
Decontamination:
Activated charcoal to early presentations
Enhanced elimination - None
Antidote - Digibind (Digoxin immune FAb)
indications:
Arrest
Life threatening arrhythmia
Ingested dose > 10mg adult, 4mg child
K+>5
Serum dig level > 15ng/ml. |
|
|
Term
Chronic Digoxin Toxicity
-Clinical Features
-Management |
|
Definition
Clinical Features
-Cardiovascular
-1-->3rd degree HB, AF with slow ventricular rate
-Increased Automaticity
(Ventricular ectopic, VT)
Hypotension, Syncope
CNS
Drowsiness, confusion
GI symptoms
(often mild)
Visual disturbance (eg yellow halos)
Ix - ECG important
UEC - Hypokalaemia exacerbates toxicity, Dig causes hyperkalaemia
Digoxin level
Rx -Resus and supportive care.
Routine cares futile in arrest - ALS temporising while awaiting digibind --> 5 ampoules + continue CPR for 30 min after.
-If Dig AB not available as temporising measure treat
1: hyperkalaemia (Insulin / Dextrose, Na HCO3) NO CALCIUM.
2:Bradyarrhytmias - Atropine .6mg to 3mg. Pacing unlikely effective
3: Ventricular disrythmias --> Lignocaine 1mg / kg.
Supportive
-Correct hypokalemia
-Correct hypovolemia
-Address inter-current illness
Decontamination / Enhanced elim not useful
Antidote - Digoxin immune FAB.
Indicated with clinical features of digoxin toxicity and any supratherapeutic level (more cost effective and safer than prolonged observation!)
(Normal Dig level =0.5-1 ng / ml. |
|
|
Term
Glyphosphate Poisoning
Clinical Features
Risk asessment
Management |
|
Definition
Herbicide - Corrosive upper airway and GI effects in high concentrations.
Myocardial depression, hypotension and resultant MODS can occur.
Risk asessment - Concentrated formulas are dangerous - diluted glyphosphate is generally benign >150mls poses risk of airway damage and severe toxicity.
Rx - Routine Supportive care.
-Intubate early if stridor /airway compromise
-Routine Haemodynamic support
-No Decontamination or antidotes.
-Enhanced elimination - dialysis is effective but rarely indicated. |
|
|
Term
Hydrocarbon Poisoning
Clinical Features
Risk asessment
Management |
|
Definition
-CNS depression, seizures and rarely cardiac dysrythmias. Aspiration causes a chemical pneumonitis.
Risk asessment
-CNS depression and seizures major risk - 1-2 ml / kg of solvent usually required to cause significant toxicity
-10 ml of eucalyptus oil causes significant toxicity.
MAnagement
-Conventional Resus andSupportive therapy
+Consider metoprolol IV for Vetricular arrythmia.
-Manage seizures with benzodiazapines.
Decontamination: Remove clothes, wash skin
NO ACTIVATED CHARCOAL.
No enhanced elimination / antidotes.
Disposition: Asymptomatic with normal vitals at 6 hours fit for discharge. |
|
|
Term
Hydrofluric Acid Poisoning
Clinical Features
Risk assessment
Management |
|
Definition
-Used in de-rusting, etching, industrial applications
-Inadvertant topical exposiure is common - Cuases delayed pain at the site of exposure followed by blanching and then blistering / tissue loss (often after days)
More dilute solutions cause more delayed presentation.
Systemic flurosis occurs with large topical exposiure - hypocalcaemia, hypomagnesiaemia + hyperkalemia and cell death. Causes long QT, ventricular arrythmias and cardiac arrest.
Risk Asessment - 2.5% BSA 100% HF --> Systemic flurosis
11% BSA 23% HF --> Systemic flurosis.
100 mls PO dilute (6%) or any concentrated ingestion is life threatening. As is any paediatric ingestion.
Rx- Resus / supportive care
significant topical exposure is a time critical emergency
RESUS
- For ventricular dysrythmias / arrest
-ALS
-Intubate / Hyperventilate
-Calcium - 60mls Ca Gluconate 10%, 20 mls CaCl 10% Repeat every 5 mins to return of perfusing rhythm
-MgS04 - 20mmols IV
-Na HCO3 -100mmol IV
Otherwise routine supportive care.
Ix - Routine screening.
Serial ECG for QT as surrogate for hypocalcemia
VBG / ELECTOLYTES (ionised calcium)
Decontamination
Remove cloths
Wash well
No enhanced elim.
Antidotes: Calcium - IV
Calcium gluconate gel (10ml in 30 ml lubricant)
+/- local infiltration /;regional infusion of Ca GLUCONATE
Disposition - All patients at risk of systemic flurosis need monitoring for 12 hours in an environment equipt to detect and manage cardiovascular collapse. Need normal ECG without calcium administration for discharge. |
|
|
Term
Hydrogen Peroxide
Risk assessment
Ix
Rx |
|
Definition
-<30ml dilute (3%) solution - Mild GI effects
>30mls 3% --> More severe GI corrosive effects, may cause Gas embolism from release of O2
-Concentrated (10%)ingestion
Life threatening GI / Airway corrosion
-Life threatening Gas embolism. / Rupture of GI tract
Ix - Standard screening
FBC / UEG / ABG
Consider CXR / AXR / CT Abdo / Chest (?perforation)
CT head (Gas embolism)
Endoscopy for significant GI / airway symptoms or concentrated ingestion.
Rx- Standard Resus / Supportive Care +
-Early airway management if features of upper airway oedema / obstruction.
-Hyperbaric therapy for Gas embolism (particularly CNS embolism with neurology)
-NGT to relieve Gaseous distension of stomach
Decontamination- remove clothes and wash
No enhanced elimination / antidote |
|
|
Term
Iron Overdose
Clinical Features
Risk Assessment
Ix
RX |
|
Definition
Clinical Features - Mostly GI, Hepatic / cardiovascular.
1:0-6 hours: GI effects -Direct corrosive action - abdominal pain, vomiting , diarrhoea. Fluid loss may be sufficient to cause hypovolemic shock.
2: 6-12 hors Distribution / absorption
3: 12 - 48 hours - Cytotoxicity Interferance with metabolism
-HAGMA, hepatorenal failure, Shock from vasodilation + 3rd space losses.
4: Acute hepatic failure, Jaundice coma, hypoglycemia, coagulopathy, high aminotransferases. High Mortality.
5: Delayed features - esp cirrhosis / GI strictures
Risk asessment - Based on Dose of ELEMENTAL iron.
< 20mg / kg - assymptomatic
20-60 - GI effects
60-120 - Systemic toxicity / HAGMA
>120 - potentially lethal
Ix - Routine Screening (ECG/ BSL / paracetamol
Specific - Serum Iron - peaks 4-6 hours
Peak> 90mmol / L indicate systemic toxicity.
ABG / VBG - HAGMA
AXR - - (radiopaque iron)
Rx - Standard Resus and supportive care, particularly.
-Aggressive fluid replacement (GI losses and 3rd spacing
Decontamination
-AC does not work!
-Whole Bowwl irrigation
+/- Endoscopic removal
-No enhanced elimination
Antidote - Desferrioxamine chellation for systemic toxicity (shock, metabolic acidosis OR predicted with serum level >90)
Disposition - Home if asymptomatic at 6 hours / ingestion < 60mg / kg. |
|
|
Term
Isoniazid Overdose
Clinical Features
Ix
Rx |
|
Definition
Rare overdose (anti TB drug)
Structurally similar to pyridoxine and inhibits It's activation to P5p which is essential in the conversion of Glutamate to GABA.
Therefore acute GABA deficinecy develops --> Status epilepticus.
Severe lactic acidosis is secondary to status and reduced metabolism of lactate.
Ix - Routine Screesing
-ABG! - HAGMA
Rx - Routine Supportive care, in particular
-Early RSI for Status
-High dose Benzodiazapines
Decontamination - Activated charcoal after ETT.
Enhanced elimination- HD effective but too late to be useful.
Antidote = pyridoxine 1g for each gram isoniazid ingested. Urgent!
Disposition -
Asymptomatic at 6 hours can be discharged. (assuming no treatment given)
-All pts with seizures need I+V + pyridoxine + ICU. |
|
|
Term
Lead Poisoning
Clinical Features
Risk assessment
Ix
RX. |
|
Definition
Acute (usually ingestion)
-Abdominal pain / nausea/ vomiting, haemolytic anaemia, hepatitis.
-Cerebral Oedema, seizures , coma.
Chronic
-Vague Constitutional sx
-Neuropathy
Subclinical impairment of higher functions (eg: IQ)
Renal impairment
Risk Asessment - Correlation with whole blood Lead level
Ix - Routine screening
FBC - normochromic normocytic anaemia with basophillic stippling
Whole blood lead - <10mcg / dL - Minor Subclinical IQ reductions in Kids increase with values towards 10
10 -30: Subtle develepmental abnormalities in children
30-100 - Neuropathy, Non specific constitutional sx, renal impairment, decreased fertility
>100 - Severe GI sx, seizures and coma
Rx - Routine Supportive Care especially
-Treat seizres with titrated benzodiazapines
-Mannitol 1g / kg / Dexamethasone 0.15mg / kg for Cerebral oedema
Decontamination
-Endoscopic ingested FB removal
-Laxatives / WBI if beyond Gastro / oesophageal junction
-Sugical removal of bullets.
No enhanced elim
Antidotes - EDTA (sodium calcium edatate) (IV chelation) for Pt with serum lead >100 or encephalopathy.
Succimer (PO) for symptomatic pts without encephalopathy or lead >60 adults, >45 (children) |
|
|
Term
Lithium Toxicity
1: Acute -
Clinical features
Risk asessment
Rx
2: Chronic
Clinical Features
Risk asessment
Rx |
|
Definition
Acute
-Massive acute overdose causes GI sx - abdominal pain + vomiting
With good supportive care and adequate renal function tremor may develop but significant neurotoxicity is very rare.
Rx: Routine Resus, Supportive care and monitoring
Particularly:
-Replace Fluid defecit - !V NS bilus and reasess.
-Monitor Urine output and electrolytes.
-Monitor neurological features.
No decontamination or antidotes.
Enhanced elim
-Haemodialysis effective but rarely required if normal renal function, adequate hydration / urine output.
Disposition - medically clear for discharge if lithium level < 2.5 and falling + not neurotoxic.
Chronic:
Occurs in context of impaired renal function in pts on Lithium
Risk asessment:
Obtundation or seizures indicate severe toxicity at high risk of permanent neurological sequellae
Clinical Features
-Predominantly neurological.
-Grade 1 - tremor, hyperreflexia, weakness, ataxia.
Grade 2: hypertonia, hypotension, stupor
Grade 3: Coma, seizures, myoclonus
Ix: - EUCs (esp Na+)
-Lithium level - correlates poorly with CNS symptoms but useful in decision to dialyse and monitor progress.
Rx
Routine Supportive care
Resus unlikely to be necessary except in severest neurotoxicity - (Airway protection / Rx Seizures)
Close attention to Fluid balance / urine output serum electrolytes (esp Na+)
No decontamination
Enhanced elimination - Haemodialysis for Serum lithium > 2.5mmol / L + features of neurotoxicity.
SLOW resolution, prolonged / repeated HD common. |
|
|
Term
Local Anaesthetic Toxicity
-Clinical Features
-Rx |
|
Definition
-Usually after iatrogenic either wrong dose or inadvertant IV / IA administration.
-CNS toxicity - Perioral numbness,ALOC, Seizures
CVS toxicity - Ventricular dysrhythmias. Hypotension, Cardiovascular collapse, asystole.
-Methaemaglobinemia (initially blue lips can progress to Tissue hypoxia + death) Not dose dependant - especially prilocaine.
Rx - Routine Resus and Supportive care
-I+V if obtunded or Cardiovascular toxicity.
-Treat hypotension with IVT + ionotropy if unresponsive.
-Treat venticular dysrhytmias with Na HCO3 boluses.
-Treat Seizures with titrated benzodiazapines
No Decontamination / enhanced elimination.
Antidote - Intralipid 1-1.5ml /kg bolus over 1 minute and repeat once or twice @ 3-5 min. . Indicated for refratory arrest. Consider (unproven) for HD compromise/ neurotoxicity)
-Methylene blue for methaemaglobinemia associated. |
|
|
Term
Mercury Poisoning
Risk assessment
Rx |
|
Definition
-Inadvertant topical exposure or ingestion of elemental mercury is benign.
-Inhalation of aeresolised elemental mercury (eg vaccuming spill) can cause systemic toxicity + interstitial pneumonitis.
-Ingestion of inorganic mercury salts can cause severe hamorhagic gasstroenteritis with massive fluid loss.
-Acute exposure to organic mercury --> Acute GI sx, tremor, respiratory distress + DELAUYED neurotoxicity - often permanent (psych, ataxia, peripheral neuropathy, weakness / paralysis)
Chronic exposure --> predominantly neuropsychological dysfunction (Mad as a hatter!).
Rx - Routine Supportive Care
-Inorganic salts may need very aggressive Fluid resusitation.
Decontamination
-Elemental: remove clothing / from skin. PO PEG an option for deliberate massive ingestion. Avoid vaccuming, discard carpets, effected surfaces.
-Organic - Activated charcoal.
Enhanced Elimination - None for elemental or inorganic.
-polythiol resin PO may be useful for organic mercury.
Antidotes
Chelation: Dimercaprol (inorganic salts only)
Penicillamine / Succimer
Indicated for symptomatic toxicity OR elevated blood (>200mcgl / L)/ urine (>100mcg/ L) mercury levels
Follow up includes public health response to mercury spill. |
|
|
Term
Methotrexate Overdose
Clinical Features
Rx |
|
Definition
-Folate analogue
Potentially lethal bone marrow depression, gastrointestinal, Hepatic and renal injury.
Risk: single dose - >
500mg (5mg /kg children)
Serum levels define risk of toxicity.
Repeated supra-therapeutic dosing 3 0r more days of weekly dose) can cause toxicity.
Ix - UEC (renal function), MTX level.
Rx
- Routine supportive care
- WBC support with gCSF,
Decontamination
-Activated harcoal within 2 hours of ingestion
No enhanced elimination
Antidote
Folinic Acid 15mg PO, IV, IM every 6 hours
indicated for
- ingestion >500mg (5mg / kg)
-Symptomatic patients
-MTX level above treatment threshold
-Abnormal renal function
-Repeated supra-therapeutic administration.
Disposition - Medically clear if asymptomatic, 6 hour MTX level below threshold for treatment for acute
Admit all repeated supratherapeutic ingestions for at lease 3 days folinic acid.
Note antidote is FOLINIC acid not folic acid. |
|
|
Term
NSAID OD
-Risk asessment
-Rx |
|
Definition
-Even very large ingestions are usually benign with minor GI symptoms)
-MAssive ibuprofen ingestion (>300mg / kg can cause shock, coma, seizures, acute renal failure and death,
-Mefanamic acid in OD commonly causes seizures
Ix - Routine screening, no levels.
VBG - shows HAGMA - usually self resolving.
Rx - Routine Supportive Care only.
Disposition: Medically clear for dischcarge if asymptomatic with normal vitals @ 4 hours.
Symptomatic patients usually manageable on ward environment
ICU only for Very rare severe toxicity |
|
|
Term
Organochloride Poisoning
Clinical features
Rx |
|
Definition
-Chlorinated pesticides (eg DDT)
-GABA antagonists --> Neuroexitatory
Causes ALOC, fasciculation, myoclonus and seizures.
Hypotension, cardiac dysrhthmias.
HEpatic and renal dysfunction.
Rx
Routine Resus and Supportive Care.
Decontamination - remove cloths, wash skin.
Activated charcoal only after ETT.
No enhanced elimination or antidote. |
|
|
Term
Organophosphate / Carbemate Poisoning
Clinical Features
Risk assessment
Management |
|
Definition
Organophosphated are anticholinesterases. Initially reversible then irreversible aging occurs. Carbemates don't age.
Features - Cholinergic crisis
muscarinic - DUMBBBELS
Diarrhoea, urination, meiosis, brochoconstriction, bronchorhoea, bradycardia,,emesis, lacrimation, salivation
Nicotinic - Tachycardia, fassciculateion, weaknes repiratory paralysis.
-intermediate (2-4 days) organophosphate repiratory paralysis ? Cause
-Delayed OIDPN organophosphate induced delayed polyneuropaty
-Chronic neuropsychiatric disturbance
Risk asessment
- Any intentional OP ingestion potentially lethal
Inadvertant exposure (toopical or inhalation can cause syndrome but not usually life threatening.
Carbemates produce a less severe picture of shorter duration and are less likely to be lethal
RX
RESUS
-Potential Life threats - COMA, Hypotension, Seizures, Respiratory failure
-Escalating atropine Meiosis, sweating, Bradycardia, hypotension, poor air entry
1.2mg (children 50mcg /kg)+ double dose every 5 mins until resolution of secretions / good air entry.
-Pralidoxime (reactivates AChE)2g IV bolus + infuse @ 0.5 g / hour. (For OP only, not carbemates)
-Likely need for I+V + haemodynamic support.
Routine Supportive Care.
Decontamination - concurrent with Resus - Remove clothes, wash skin.
Staff utilise standard precautions (staff exposure doesn't cause significant toxicity)
No activated charcoal.
No enhanced elimination.
Disposition.
Any intentional ingestion observed for 12 hours.
Observe 24 hours post cessation of Oximes
Potential inadvertabt occupational exposure only needs assesment if symptomatic. |
|
|
Term
Acute paracetamol OD
Risk stratification
Ix
Rx |
|
Definition
>150mg/ kg or >10g (whichever is less) in 8 hour period is at risk of acute hepatic failure.
(Adult)
>200mg/kg (child <8)
Ix
- presentation within 8 hours - paracetamol @ 4+ hours
>8 <24 hours -
serum paracetamol + LFTS
>24 hours - paracetamol ELFTs, glucose, Coags.
Rx:
Resus rarely required.
Routine supportive cares.
Decontamination of minimal benefit
(Activated charcoal MAY reduce need for NAC if subsequent level below cut off for NAC)
No advanced elimination
Antidote:
NAC infusion (150mg/ kg NAC 200ml 5% dextrose over 15 min, 50mg/ kg NAC in 500ml 5% dextrose over 4 hour, 100mg / kg NAC in 1L 5% over 16 hours)
Start within 8 hours if para level > treatment threshold - 20 hours NAC and No further ix required.
presentation > 8 hours - Start NAC immediately. May cease if para level < treatment or ALT normal after 20 hr infusion.
-presentation > 24 hours - start NAC. If ALT normal can cease.
Continue until ALT falling (monitor every 12-24 hours)
If ALT>1000 also check coags / glucose. |
|
|
Term
Repeated Supratherapeutic Paracetamol ingestion
Risk assessment
Rx |
|
Definition
Risk of hepatotoxicity with
Adults -
>200mg / kg or >10 G in 24 hours
>150mg / kg >6g per 24 hours for 48 hours.
>100mg / kg >4g per 25 hours in patients with risk factors
Children
>200mg/kg in 24 hours
>150mg / kg each 24 hours for 48 hours
>100mg/ kg / 24 hours for 72 hours.
Ix - Measure ALT and serum paracetamol
If ALT<50, para <20mg/ L no treatment required
If not - Start NAC + recheck ALT + paracetamol level in 8 hours.
- If ALT normal or static, stop NAC
-If not Continue NAC and monitor ALT 12 hourly +/- BSL, Coags, VBG as indicated. |
|
|
Term
Paraquat Poisoning
Clinical Features
Risk asessment
Management |
|
Definition
Mechanism - Causes free radical damage to tissues.
Clinical Features
Early - Corrosive injury to GI tract.
<48 hours - Progressive metabolic acidosis,Tachycardia, tachypnoea, multiple organ failure (early with large ingestions --> death within 24 hours)
Moderate ingestions may not develop acute toxicity but develop delayed pulmonary fibrosis with increasing dyspnoea and hypoxia over days to weeks.
Ix - Routine screening.
-Specific - FBC, ELFTs, COAGS (detect multi organ failure)
CXR / lung function - detect pulmonary fibrosis.
Serum paraquat - confirms ingestion and prognosticates. Urine paraquat confirms ingestion.
Rx - The ONLY poisoning where decontamination takes priority over resus
-Soil / food / anything at scene reduces absorption.
-Activated Charcoal 50g / 1g/ kg for children ASAP
-Early Haemodialysis needs consideration.
-Immediate management of ABCs rarely required
- Early airway management only for stridor // indication of corrosive airway injury.
B: AVOID HYPEROXIA (free radicals) titrate to sats = 90%)
Decontamination as above
Enhanced elimination - HD
No antidotes
Disposition
>250ml of 20% have hopeless prognosis and should be palliated.
Any deliberate exposure to intensive care.
inadvertant exposure who are asymptomatic pt with negative urinary paraquat can be discharged. |
|
|
Term
Antipsychotic OD
Clinical Features
Risk asessment
Rx |
|
Definition
Phenothiazine (eg: chlorpromazine)
Butyroophenones (eg: Haloperidol, Droperidol)
Clinical Effects - CNS depression,
Anticholinergic effects
QT prolongation and torsades WERE common with thioridazine but are now not clinically significant since it's withdrawl.
Chlorpromazine can cause coma requiring intubation with doses > 5g.
Ix - Routine screening and ECG.
Rx - Meticulous supportive care along conventional lines
Decontamination - Activated charcoal after ETT only.
No Enhanced elim or antidote
Disposition, if asymptomatic, normal vitals and ECG at 6 hours medically clear. |
|
|
Term
Potassium chloride Poisoning
Risk asessment
Management |
|
Definition
> 40 x 600mg controlled release tablet potentially causes life threatening hyperkalaemia.
> 3 tabsin 10kg toddler.
Ix- Routine screening including ECG
Blood gas / electrolytes - K+
AXR confirms ingestion of radiopaque K+ tabs
RX - RESUS - Routine ABC support as indicated.
immediate life threat is venticular arrythmia / asystole.
Urgent management of hyperkalemia along conventional lines
(Ca2+, Bicarb, Salbutamol, insulin / dextrose, resonium, Haemodialysis)
Decontamination
Whole bowel irrigation (doesn't prevent hyperkalemia or need for dialysis)
Enahanced elimination
-Haemodialysis - plan for on presentation.
indications - Confirmed > 40 tablet ingestion
-Hyperkalaemia > 8
-Renal impairment
-Cardiovascular instability. |
|
|
Term
Quinine Toxicity
Clinical Feature
Risk assessment
Rx |
|
Definition
Clinical
Cinconism
(vertigo, tinnitus, deafness, vomiting, nausea)
Cardiovascular -
Hypotension, tachycardia, QRS prolongationtype 1a effects - long QT, torsades.
CNS -
ALOC, confusion
Seizures are rare
Direct retinal toxicity - visual disturbance / blindness , usually self resolving but may persist.
Risk asessment
>1g can cause cinchonism
>5g has potential for severe toxicity.
2 tabs (600mg) in children potentially lethal.
Ix - Routine screening ECG / BSL, para
specific - Serial ECGs (QRS duration, HR, QT)
Visual field mapping / VAs if viusual symptoms.
Rx RESUS - Routine resuscitation especially.
-Coma --> I+V
-Broad complex tachyarrhthmias
-Intubate and hyperventilate
-NaHCO3 bolus to narrowing QRS and HD stability pH 7.55.
-Torsades
-Correct hypoxia /hypokalemia
- mgs04 20 mmol.
-consider isoprenaline / overdrive pacing for HR 100-120
-Treat Seizures with titrated benzodiazapine.
Routine Supportive Care.
esp - antiemetics and IVT for cinchonism.
Decontamination - activated charcoal for intubated pts < 4ghours
Enhanced elimination - MDAC for anyone with >5g ingestion or any visual disturbance.
Disposition - ECG monitoring for at least 6 hours
If ECG normal, asymptomatic at 6 hours can discharge. |
|
|
Term
Salicylate toxicity
Clinical Features
Risk asessment
Ix
Management |
|
Definition
Aspirin or Methyl salicylate
Clinical Features
Tinnitus, nausea vomiting, hyperventilation. Metabolic acidosis and respiratory alkylosis.
Severe toxicity --> Coma and Seizures.
Risk assessment - > 300mg /kg = Severe Toxicity (metabolic acidosis, Coma and Seizures)
Ix - Routine screening ECG/ BSL, paracetamol.
specific - ABG/ VBG
Salicylate Level
Rx:
Resus
-Routine atttention to ABC's
-If Obtunded / Airway threatened - RSI - Controlled hyperventilation to maintain respiratory alkylosis.
Life threats = Coma and seizures - rx with benzodiazapines as normal.
Routine Supportive Care. Monitor MEntal state, acid base status. Ensure adequate IV rehydration.
Decontamination - Activated charcoal up to 8 hours after airway protection.
Enhanced elimination
1: Urinary Alkylisation
-Correct hypokalemia
-1-2 mg/kg NaHCO3 bolus followed by 100mmol NaHCO3 / 1L dextrose @ 250ml / Hr +/- KCL 20mmol
-Monitor serum pH and K+
-Aim for urinary pH > 7.5
-Continue until Toxicity resolved.
2: Haemodialysis
Indications
- Salicylate level >4.4mmol / L + rising / despite alkylisation
-Severe toxicity: Altered mental state, acidemia, enal failure.
-Very High salicylate levels (>7.2 mmol/ L acute, >4.4 mmol/ L chronic.
Disposition:
Admit all symptomatic patients for enhanced wlimiation until asymptomatic, normal acid base status and serum levels within therapeutic range (< .2.2)
ICH / HDU for significant toxicity. |
|
|
Term
Of the SSRI's which causes prolonged QT?
What is the relevance? |
|
Definition
Escitalopram / Citalopram.
Doses > 600mg need cardiac monitoring for 8 hours
Doses greatet than 1000mg need monitoring for 13 hours
At this point if QT is normal on 12 lead ECG Pt can be medically discharged.
Other SSRIs do not prolong QT and are managed as per Serotonin Syndrome Slide. |
|
|
Term
Strychnine Poisoning
Clinical Features
Risk Assessment
RX |
|
Definition
-Rodenticide, CNS Glycine antagonist. Leads to reduced descending inhibition and skeletal muscle spasm.
Risk asessment
-Any deliberate ingestion likely to be lethal
-Even an accidental taste in a child may be lethal.
-30-100mg (1g 0f 0.03% powder potentially lethal.
Rx - Immediate life threat is skeletal muscjle spasm and respiratory failure.
-Urgent RSI / Skeletal muscle paralysis and ventilation if rigidity compromising ventilation. LOC not impaired therefore important to ensure adequate sedation.
Less severe toxicity (eg twitching) Rx with titrated benzodiazapines.
Routine supportive care
Decontamination- consider activated charcoal after intubation only
No enhanced elimination
Disposition - If asymptomatic / well at 4 hours can medically clear.
If symptomatic - HDU environment for very close observation
-Muscle spasm herald rapid deterioration --> Respiratory failure, rhabdomyolysis, acidosis therefore need very close observation and early intervention. |
|
|
Term
Sulfonurea poisoning
Clinical Features
Risk assessment
Rx |
|
Definition
Potential for delayed , profound and prolonged hypoglycaemia.
Risk assessment:
-One tablet in a non diabetic or child can --> hypoglycaemia
Rx: RESUS
Immediate life threat is ALOC from hypoglycemia
-50 mls 50% (5ml / kg 10% in children) glucose to hypoglycaemic pt
-Monitor BSLs at least hourly.
- Maintain euglycemia with glucose until Octreotide infusion can be started.
Decontamination - Activated charcoal if <1 hour after airway secured (4 hors for SR prep)
No enhanced elimination
Antidote = Octreotide 1mcg / kg bolus, 1 mcg / kg / hour infusion (50mcg / 25mcg / hour in adults)
Disposition - hypoglycemic pts need admission - can be discharged if maintaining euglycemia for 6 hours on normal diet following cessation of occtreotide.
Asymptomatic, euglycimic patients at 8 hours may be discharged. |
|
|
Term
Theophyline Toxicity
Clinical Features
Risk Assessment
Rx |
|
Definition
Clinical Features
Early - Anxiety, tremor, vominting sinus tachycardia
Severe Toxicity
-CVS -, SVT, AF/ VT
Hypotension
CNS - Seizure ALOC,
Metabolic changes - Hypokalemia, metabolic acidosis, Hypomagnesemia, hypophosphatemia, hyperglycemia.
Risk Assessment - Narrow therapeutic index.
>10mg / kg symptomatic
>50 mg / kg potentially lethal.
-Theophyline level can refine risk assessment - >80mg / L severe toxicity > 100mg / L potentially lethal.
Rx -
RESUS - Potential Life threats - Hypotension, Seizures, Arrhythmias.
-Hypotention - 20ml /kgg NS bolus +reasess and repeat, may requre NAD.
-Arrythmias - SVT B-Blockers -Titrated IV metoprolol. Correct hypokalemia.
Seizures - Titrated benzodiazapines
RESUS / Supportive care a bridge to definative treatment = Haemodialysis.
Decontamination - Activated charcoal post intubation for all patients (even delayed)
Enhanced elimination - HD
indications
1: Severe toxicity (arrhthmia, sezure)
2: Level > 100mg/L (acute)60mg / L Chronic
Disposition - Observe for 6 hours post ingestion (12 hours for SR) - If asymtomatic with normal Vitals can discharge.
Monitored environment for all symptomatic pts.
ICU with HD facilities for high risk (symptomatic or high levels) |
|
|
Term
Tricyclic Antidepressant Poisoning
Clinical features
Risk Assessment
Ix
Rx |
|
Definition
Amitriptyline, Clomipramine, Dothiepin, Doxepin, Imipramine, Nortiptyline, Trimipramine.
Clinical Features
CNS - Agitation, Delerium, ALOC, Seizures
CVS - Tachycardia / Hypotension, Wide QRS, tachyarrhythmias,Long QT,Broad complex bradyarrhthmias occur pre-arrest.
Anticholinergic effects:
Agitatimon, Delerium, dry mouth, mydriasis, dry / warm / flushed skin, urinary retention,
Risk Assessment >10mg/kg potentially lethal.
Ix - Routine screening
Serial ECG- Broad complexes (>100ms predictive of seizures, >160ms predicts arrhythmias) Long QT, Prominent R AVR.(>0.7R/S ratio)
Resuscitation
A-Intubate / Ventilate early if: GCS<12, Arrhythmias, Seizures.
B-Hyperventilate --> pH 7.5-7.55)
C: Treat Hypotension
-IV NS 1L + repeat
-NaHCO3 100mmol (2mmol/ kg) bolus every 2-3 minutes - end point = narrow QRS, pH =7.55.
-Persistant hypotension --> NAD @ 0.1mcg/ kg / min + titrate MAP =65.
Tachydysrhthmias - NaHC03
lignocaine 1.5mg/ kg IV is 3rd line (after HCO3 and hyperventilation for tachydysrhthmias
-Defibrillation unlikely to succeed.
D: Treat seizures with titrated Benzodiazapines. Exclude hypoglycemia.
Routine supportive care - Continuous Cardiac monitoring
Sedation
Decontamination - Activated charcoal after intubation
No enhanced elimination
Antidote = NaHC03
Disposition - Asymtomatic, normal ECG, normal vitals at 12 hours --> medically clear
Minor ECG changes - Cardiac monitoring, Serial ecg until normal.
Severe toxicity --> ICU.
Note: If arrested - continue resus until intubated, hyperventilated + HCO3 to pH =7.55 (Good outcomes after prolonged arrest) |
|
|
Term
Valproate Toxicity
Clinical Features
Risk Assessment
Ix
RX |
|
Definition
Clinical Features - Promotes CNS release of GABA. In large doses inhibits mitiochondrial metabolism and leads to multi-organ failure.
-Progressive decline in LOC parallels rising serum levels
-Absorption slow and erratic --> Coma can be delayed up to 12 hours post ingestion.
High doses --> Multi-system failure, hypotension,Cerebral Oedema.Lactic Acidosis, hypoglycemia, hypernatremia, hypocalcemia, hyperammoneaemia, bone marrow suppression
Risk assessment - Severe toxicity with multi-organ dysfunction > 400mg/ kg.
>1000mg / kg potentially lethal.
Ix - Routine screening
Specific - BSL (hypoglycemia)
UEG - Electrolyte disturbance
Serum Valproate - Confirms ingestion, refines risk assessment, indicates need for dialysis. Repeat 4-6 hourly if ALOC or >400mg/ kg ingested until declining level.
Rx: RESUS
Routine Care
Intubate early if large ingestion and declining GCS.
Supportive Care - Routine
Decontamination - Activated charcoal for >400mg / kg after ETT.
Enhanced elimination: - Haemodialysis is lifesaving in massive ingestions
Indications:
>1g/ kg ingested + serum level > 1000mg / L
- Serum level > 1500mg / L any time
-Clinically severe poisoning with lactic acidosis or haemodynamic instability.
-Initiate Early!
No Antidotes
Disposition - Ingestion <200mg / kg - observe in ward environment for 8 hours. If asymtomatic then medically clear |
|
|
Term
Venlafaxine / Desvenlafaxine OD
-?Drug class
-Clinical Features
-Risk Assessment
-RX |
|
Definition
Drug Class
-SNaRI
also Na+ blocking activity in high doses.
Clinical Features
-Seizures (often delayed up to 16 hours) Progressive increas in risk with increased dose.
-Dysphoria, anxiety, tachycardia, mydriasis, sweating may precede seizures. Hypotension (often delayed) after massive ingestions. Prolongation of QT / QRS / Dysrhythmias only with the largest ODs
Risk Assessment
-Dose dependant risk of seizures
-In High doses (<7g) Risk of cardiotoxicity similar to TCAs.
Rx- RESUS
Life threats = Seizures - Rx with titrated benzodiazapines.
In massive doses - broad complex tachydysrhthmias (MAnagement as per TCA OD with HC03 and hyperventilation)
-Intubate early if > 7g ingestion clinical features consistent.
-Serotonin syndrome possible with Co-ingestants (monitor and manage hyperthermia)
Supportive care - Routine.
In particular titrated IV benzodiazapines for agitation + prevention of seizures.]
Decontamination - Activated charcoal after intubation if > 7g
No enhanced Elimination
No Antidotes.
Disposition
- Observe all ODs with IV in situ for all ingestions for at least 16 hours.
-Cardiac monitoring for 6 hours, can discontinue if ingestion <4.5g and normal ECG.
>4.5 g need cardiac monitoring for 12 hours. |
|
|
Term
Anticholinergic Syndrome
-Clinical Features
-Complications
-Causes
-Rx |
|
Definition
-Clinical
Agitated Delerium with peripheral antimuscarinic features
Central - Delerium, hallucinations, myoclonus, seizures (rare)
Peripheral
-Dry
-Red
-Ileus
-Urinary Retention
-Tachycardia
-Hyperthermia
-Mydriasis
(Dry as a bone, red as a beet, hot as a hare, mad as a hatter)
Causes
-Antipsychotics (eg halpoeriol, droperidol)
-Antihistamines (promethazine)
-Antiparkinson'sDrugs
-Anticholinergics (atropine)
-Tricyclic antidepressants
-Datura
+ many others.
-Complications
Hyperthermia
Deyhdration
ARF
Rhabdomyolysis
Injury
Aspiration
Rx: Resus - Treat Seizures with benzodizapines
Supportive care - Treat agitation with Benzo's NOT droperidol!
IV rehydration
1:1 nursing in quiet environment
Catheterise if urinary retention
Ix: - Screening ECG / paracetamol
Specific - Electrolytes (Cr? AKI)
CK (rhabdo)
Antidote - physostigmine
(Consider in delerium difficult to control with Benzo's)
Remember risk of cholinergic crisis. |
|
|
Term
Neuroleptic Malignant Syndrome
Clinical Features
Rx |
|
Definition
Clinical
Altered Mental Status
-Confusion, Delerium, Coma
Autonomic Instability
-Hyperthermia, Tachycardia, Hypertension, Respiratory Irregularities, Cardiac Dysrythmias
Neuromuscular Changes
-Lead Pipe Rigidity, Bradyreflexia (differentiates from Seretonin syndrome with hyperreflexia)
Mutism, Staring, Dystonia, posturing. Chest wall rigidity may impede ventilation.
Clinical diagnosis once DDx considered and excluded
(eg: Seretonin syndrome, encephalitis,metabolic encephalopathy, malignant hyperthermia, anticolinergic syndrome, sympathomimetic syndrome)
Rx: Establish Resus.
-Severe hyperthermia (> 39.5) / Coma indications for RSI and neuromuscular paralysis.
-Detect and correct hypoglycemia
-Detect and correct hyperthemia (Severe > 39.5 with RSI / paralysis / active cooling)T>38.5 core temp monitoring.
Supportive CAre / monitoring:
Sedation with benzodiazapines controversial (? some role in causation) but probably indicated.
Monitor temp.
IV fluid rehydration
Cease Causative agents
Consider VTE prophylaxis
Ix - Screening ECG / paracetamol
Detect complications - CK, UEG / LFT (renal function) Blood gas.
Exclude DDX - Ct / MRI head / LP.
Antidote Rx:
Bromocriptine (Da Agonist) 2.5mg Q8hr PO / NG. mod -severe Autonomic instability
Dantrolene (Severe muscle rigidity and fever)2-3 mg / kg / day. |
|
|
Term
Clonidine OD
Clinical Features
Management |
|
Definition
Miosis, Sedation, Respiratory depression, bradycardia and hypotension (usually without deficient end organ perfusion)
Rx - Simple supportive measures usually adequate
Extreme doses may need intubation and ventilation and chronoropy / ionotropy
Trial of naloxone may be indicated for repiratory depression (controversial) |
|
|
Term
Metformin Overdose
Clinical Features
Risk assessment
Rx |
|
Definition
-Acute OD usually benign
Risk of severe lactic acidosis progressing to Shock and death in adults with >10g ingestions, children >1700mg.
Chronic toxicity occurs with renal impairment in pts taking metformin.
Rx - Routine RESUS / Supportive care
-Na+ HCO3 may be a temporising measure awaiting HD for severe lactiv acidosis (particularly with concominant hyperkalemia)
-Hypoglycemia is rare and responds well to dextrose
Decontamination - Activated charcoal for within 2 hours >10g ingestion
Enhanced elimination - Haemodialysis lifesaving - corrects Acidosis and removes metformin.
Indicated - Any lactic acidosis from therapeutic admin
-Worsening lactic acidosis or emerging instability in acute ingestion. |
|
|
Term
Funnel Web spider Bite
-Clinical Features
-Management |
|
Definition
-Prevents inactivation of Na+ channels --> Neuromuscular excitation.
-Vomiting, agitation, headache, abdo pain.
-Autonomic, sweating, piloerection, salivation, lacrimation,
-CV htn, hypotension, tachy / brady arrythmia, pulm oedema.
-NM: fasciculation, spasm, weakness, coma, oral paraesthesia.
Rx.
Risk asessment - potentially lethal envenomation, manage in area equip. for resus.
Resus:
-Life threats - Hyper / hypotension, Resp Failure, Coma, Pulmonary Oedema.
-Cardiac arrest - undiluted antivenom 4 U (or all available) as push + ALS.
Ix - exclude differential / complications.
Supportive Care / Monitoring - Routie, analgesia, antiemesis.
-PIB
Antidote = Funnel web antivenom - 2 ampules in clinical envenomation - nitor Ongoing envenomation repeat dose 15 mins.
Disposition - Observe 4 ghours - no envenomation = home
Envenomated - monitor 12 hours post antivenom. |
|
|
Term
Indications for Digibind
Dose |
|
Definition
Acute toxicity
-Hyperkalemia (K>5)
-Ingested Dose > 10mg adult / 4mg child
-Serum level > 15nmol / ml
-Arrest / life threatening Dysrhythmia
Dose based in ingested dig dose 40mg = 0.5mg digoxin
dose in ampules =ingested dose (mg) x 0.8 (bioavailability) x 2.
Chronic Toxicity Indications
-Arrest
-Life threatening dysrhythmia
-In general any sx of digitalism in the setting of an elevated serum level (normal <1.3nmol / ml) (Reduces hospitalisation time)
Dose based on serum level - 1-2 ampules usually sufficient. |
|
|
Term
Risk asessment - Toxic doses
-Ethylene glycol
-Methanol
-Propanolol
-Verapamil / Diltiazem
-Carbemazapine
-Colchicine
-Digoxin
-Hydrofluric acid
-Iron
-Paracetamol
-Aspirin
-Sulfonureas
-Theophyline
-TCAs
-Valproate
-Venlafaxine / Desvenlafaxine |
|
Definition
Ethylene glycol > 1ml/ kg
Methanol > 0.5 ml / kg
Propranolol > 1g potentially lethal
Verapamil / Diltiazem > 10 tabs SR prep
Carbemazapine > 50mg/kg -risk of coma, cardiotoxicity wioth extreme doses
Colchicine: Any deliberate ingestion potentially lethal
Digoxin-- Acute > 10g lethal (K+>5.5, Level > 15nmol/L)
HF acid - 2.5 TBSA 100%, 11% TBSA 23 %. Any ingestiion @ risk of systemic flurosis
Iron> 120mg/ kg elemental iron potentially lethal
Paracetamol > 10g / 150mg/kg adults
>200mg/kg children
Aspirin> 300mg/ kg severe, >500mg/kg lethal
Sulfonureas 1 tab in non diabetic or child can cause hypoglycemia
-Theophyline > 50mg / kg life threat.
-TCAs > 10mg/ kg life threatening
-> 1g / kg potentially lethal, > 400mg / kg delayed coma requiring intubation / MODS, level >7000mcmol / L --MODS, >14000 death without Haemodyalysis.
Venlafaxine: >4.5 g seizures 100%
>7g --> hypotension and cardiac dysrhythmias |
|
|
Term
Relevant Drug LEvels
-Arsenic
-Carbemazapine
-CO
-CN
-Digoxin(Acute / Chronic)
-Lead:
-Lithium:
-Mercury
-Methotrexate
-ORganophosphates
-Phenytoin
-Salicylate
-Theophyline
-Valproate |
|
Definition
Arsenic- Spot urinary arsenic > 200 helps confirm ingestion + indicates chelation.
Carbemazapine: >40mg/L expect coma, seizures and conduction abnormalities. Repeat serum levels Q 6 hr monitor progress of MDAC / HD.
-COhb -Loose correlation, 10% smoker, 50% severe toxicity +/- death.
-CN, only useful in retrospect. take before CN antidote.
-Digoxin: 0.5-1ng / ml normal range. Acute OD - Digibind for >12 ng/ ml. Chronic = symptomatic and 6hr leval supratherapeutic.
LEad: 100mcg / DL associated ith severe encephalopathy and IV chelation (EDTA) indicated >60mcg / DL --> succimer (oral chelation)
Lithium: Monitor excretion in acute ingestion. <2.5mmol / L and falling safe for discharge. Serum level > 2.5mmol / L and neurotoxicity in chronic ingestion indicates dialysis.
-Mercury Blood> 200mcg/ml, urine 100mcg / ml associated with sx + indicates chelation
-Methotrexate >5mcmol/ ml @ 6 hours indicates toxicity and folinic acid.
-Organophosphates - Red cell cholinestease levels correlate with toxicity and used to monitor withdrawl ox pralidoxime.
-Phenytoin: 50mg/ L associated with coma.
-Salicylate- >7.2mmol / L acute > 4.4mmol / L chronic indicates HD. > 4.4mmol/ L despite urinary alkylisation
-Theophyline 10-20mg / L therapeutic, > 100mg / L life threatening. > 100mg/L in acute ingestion >60mg/ L chronic ingestion indicates Haemodialysis.
-Valproate >7000mcmol/L indicates severe toxicity and indicates HD. |
|
|
