(1)
Royal Free NHS Foundation Trust, London, UK
ABCD assessment in poisoning
Airway: signs of obstruction (caustic ingestion; ACE inhibitors); loss of protective airway reflexes (CNS depression; seizures); increased secretions (organophosphates); risk of aspiration; predicted rapid progression to respiratory failure (paralysis-botulinum toxin; pneumonitis-hydrocarbons, inhalants)
Breathing: non-cardiogenic pulmonary oedema/acute lung injury
Circulation
Disability: GCS; mental state; pupil size and reaction; hypoglycaemia (ethanol, oral hypoglycaemic agents, beta-blockers, salicylates)
Exposure
Causes of altered heart rate associated with poisoning
Bradycardia: beta-blockers; calcium channel blockers; opiates; digoxin
Tachycardia: sympathomimetic agents (amphetamines, cocaine); alcohol; anti-cholinergic agents; salicylates; tricyclic antidepressants; theophylline
Causes of hypotension associated with poisoning
Vasodilatation, with venous pooling in the lower limbs: ACE inhibitors; calcium channel blockers
Myocardial depression: beta-blockers; calcium channel blockers; tricyclic antidepressants
Reduced circulating blood volume: gastrointestinal losses (vomiting: diarrhea); increased insensible losses (salicylates)
Screening evaluation with overdoses
History of overdose: what?, when?, how much?, what else?, why?
Collateral information: family/friends; paramedics; notes; contents of pockets; empty bottles
Recognition of medication: Toxbase; BNF; TICTAC (Tablet Identification Aids); NPIS; plant identification atlas
Potential sources of caustics
Acids: toilet bowl cleaners; anti-rust compounds; car battery fluid; stone cleaner; soldering fluxes
Alkalis: drain cleaners; surface cleaners; disc batteries; laundry or dishwasher detergents; denture cleaners; industrial strength bleach
Causes of toxidromes
(toxicological syndromes, consisting of a collection of physical signs that help identify the causative agent)
Sympathomimetic: beta adrenergic agonists (terbutaline); alpha adrenergic agonists (ergot alkaloids, phenylephrine), predominantly alpha-1 adrenergic agonists (ephedrine, pseudoephedrine); indirect acting (cocaine, amphetamines; methamphetamines); LSD; theophylline; caffeine; noradrenaline uptake inhibitors (MAOI);
Anticholinergic: antihistamines, antipsychotic agents, selective serotonin reuptake inhibitors, tricyclic antidepressants, atropine, scopolamine, benztropine
Cholinergic: organophosphate insecticides (nicotinic and muscarinic), neuromuscular blocking agents (nicotinic); chemical warfare nerve agents; carbamate insecticides (muscarinic); mushrooms (Boletus, Clitocybe and Inocybe species); nicotine containing products
Opiate (triad of miosis, hypoventilation and coma): codeine, heroin, methadone
Sedative-hypnotic: benzodiazepines; ethanol and other alcohols; barbiturates; quinazolines
Sedative withdrawal
Serotonin: serotonin breakdown inhibitors (monoamine oxidase inhibitors); serotonin reuptake inhibitors (SSRI; cocaine; opioids); serotonin precursors (LSD, L-tryptophan); serotonin release enhancers (amphetamine, atypical anti-psychotics: lithium, risperidone, olanzapine; atypical antidepressants: mirtazapine, venlafaxine); triptans
Alcohol withdrawal
Anti-muscarinic (anti-cholinergic) syndrome
Tachycardia
Dilated pupils(mydriasis)
Dry, flushed, hot skin
Dry mucous membranes/axilla
Urinary retention
Reduced bowel sounds: reduced peristalsis
Hyperthermia
Mild hypertension
CNS: Confusion, hallucinations, seizures, sedation, agitated delirium, myoclonic jerking and choreoathetoid movement, lethargy, coma
Cardiac arrhythmias
Absent bowel sounds
“Hot as hades, dry as a bone, red as a beet, blind as a bat, and mad as a hatter”
Features of tricyclic antidepressant toxicity
(the 3 Cs of cardiac complications, convulsions and coma)
Anticholinergic: dry mouth, dry and flushed skin, mydriasis, blurred vision, sinus tachycardia, hyperthermia, hallucinations, seizures, ileus, urinary retention
Sodium channel blockade: prolonged QT interval, AV blocks, widening of QRS complex with terminal R wave in aVR, ventricular arrhythmias (VT, VF)
Alpha-adrenergic blockade: hypotension; reflex tachycardia
Antihistamine: CNS sedation
Cholinergic (muscarinic) syndrome
Excessive salivation
Lacrimation
Bronchorrhoea
Bronchospasm; wheezing
Abdominal cramps: hyper-peristalsis
Urine and faecal incontinence
Vomiting
Sweating
Miosis
Bradycardia
Muscle weakness and fasciculations
Pulmonary oedema
Confusion or lethargy; coma
Seizures
Peripheral syndromes may be described as:
SLUDGE: salivation; lacrimation; diarrhoea; gastro-intestinal motility, emesis
BBB: bradycardia; bronchorrhoea; bronchospasm
Sympathomimetic (hyper-adrenergic) syndromes
Tachycardia
Tachypnoea
Hypertension; with severe hypertension, reflex bradycardia may occur
Hyperthermia
Sweating (diaphoresis)
Dry mucosae
Piloerection
Mydriasis
Hyperreflexia
Agitation
Delirium
Paranoid delusions
Seizures
Stroke
Acute coronary syndrome
Aortic dissection
Cardiac arrhythmias
Hyperactive bowel sounds
Rhabdomyolysis
Potential presentations with cocaine toxicity
CNS stimulation: tremors, euphoria, agitation, seizures, status epilepticus
Cardiovascular: hypertension; chest pain (acute coronary syndrome: ST elevation myocardial infarction); rhythm disturbances: ventricular tachycardia; supraventricular tachycardia; aortic dissection; dilated cardiomyopathy
Hallucinations; acute psychosis
Acute cerebrovascular accidents: cerebral infarction; subarachnoid haemorrhage; cerebral vasculitis
Pulmonary: bronchospasm; haemoptysis: alveolar haemorrhage; acute non-cardiogenic pulmonary oedema; hypersensitivity pneumonitis(crack lung); barotrauma: pneumothorax; pneumomediastinum (from coughing against a closed glottis while smoking or intranasally inhaling cocaine
Rhabdomyolysis: acute kidney injury
Gastrointestinal: bowel ischaemia; body packer syndrome; hepatitis
Obstetric and perinatal: spontaneous miscarriage, abruptio placentae, premature labour, neonatal cerebral infarction, neonatal seizures, neonatal myocardial infarction
Opioid toxidrome
Bradycardia
CNS depression
Reduced gastro-intestinal motility
Hypotension
Miosis
Respiratory depression: bradypnoea, apnoea
Hypothermia
Sedative-hypnotic toxidrome
Bradycardia
CNS depression-lethargy, obtundation
Hypotension
Hypothermia
Respiratory depression
Normal to large, sluggishly reactive, pupils
Paradoxical excitement
Slurred speech
Ataxia
Benzodiazepines:
CNS depression
Normal vital signs
No respiratory depression in oral overdose without concomitant CNS depressants
