Toxicology

A 25-year-old woman is brought to the emergency department by ambulance after her housemate found her with an empty blister pack, 2 hours after she reportedly ingested 30 × 500 mg paracetamol tablets (15 g, approximately 214 mg/kg) in a single act of self-harm. She admits to the ingestion, denies co-ingestants, and has no significant past medical history. She is alert and cooperative, denies nausea, vomiting or abdominal pain, and examination is unremarkable. Observations are: HR 78 bpm, BP 118/72 mmHg, RR 16/min, SpO2 99% on room air, temperature 36.7°C. What is the most appropriate immediate management?

A 32-year-old woman is brought to the emergency department by ambulance four hours after intentionally ingesting approximately 40 g of paracetamol (eighty 500 mg tablets) in a single episode, witnessed by her partner. She complains of nausea and has vomited twice but denies abdominal pain. She has no significant past medical history and takes no regular medications. On examination she is drowsy but rousable to voice, GCS 14, heart rate 112 bpm, blood pressure 102/64 mmHg, respiratory rate 26/min, temperature 36.8°C, and oxygen saturation 98% on room air. A venous blood gas shows pH 7.28, lactate 4.6 mmol/L, and bicarbonate 15 mmol/L. A serum paracetamol concentration taken at four hours post-ingestion returns at 1200 mg/L, well above the treatment line on the paracetamol nomogram. Liver function tests, coagulation studies and renal function are pending. Which of the following represents the most appropriate management?

A 30-year-old man is brought to the emergency department by his friends after using cocaine at a nightclub. He is agitated, diaphoretic and combative, repeatedly trying to climb off the trolley. Observations reveal a heart rate of 148 beats/min, blood pressure 196/112 mmHg, respiratory rate 24 breaths/min, temperature 38.6°C and oxygen saturation 98% on room air. Examination shows dilated pupils, profuse sweating and hyperactive bowel sounds. The 12-lead ECG shows sinus tachycardia with a normal QRS duration and no ischaemic changes. Which of the following is the most appropriate first-line management?

A 35-year-old woman is brought to the emergency department by her partner with agitation and confusion that developed over the past two hours. She has a history of major depressive disorder treated with fluoxetine and was recently commenced on tranylcypromine, a monoamine oxidase inhibitor, by her psychiatrist after a medication switch without an adequate washout period. On examination she is diaphoretic and flushed, with a temperature of 39.4°C, heart rate 138 beats per minute, blood pressure 172/96 mmHg and dilated pupils. She is tremulous, with inducible clonus and hyperreflexia that are more pronounced in the lower limbs than the upper limbs, and mild rigidity of the lower limbs. Her neck is supple and there is no photophobia. Venous blood gas shows a mild metabolic acidosis with lactate 3.1 mmol/L. Which of the following is the most appropriate next step in management?

A 4-year-old boy is brought to the emergency department by ambulance after his grandmother found him unresponsive in her bedroom. She uses transdermal fentanyl patches (75 microgram/hour) for chronic back pain and had placed several used patches in the bathroom bin, which the child had access to earlier that afternoon. On arrival his GCS is 9 (E2V2M5), pupils are 2 mm and sluggishly reactive bilaterally, respiratory rate is 6 breaths per minute with shallow effort, SpO2 88% on room air, heart rate 68 beats per minute and BP 90/55 mmHg. A used fentanyl patch is found stuck to the skin of his left flank, and another partially chewed patch is visualised in his oral cavity. Which of the following is the MOST appropriate initial management strategy?

A 45-year-old farm worker is brought to the emergency department after deliberately ingesting an organophosphate pesticide while working alone. He was initially treated with atropine and pralidoxime for a cholinergic crisis of miosis, hypersalivation, bronchorrhoea and bradycardia, which resolved over the first 24 hours. On day 3 of admission he becomes acutely unwell with worsening neck flexor weakness, difficulty holding his head up, bilateral proximal limb weakness and diplopia. He is afebrile, heart rate 96 bpm, blood pressure 128/78 mmHg, respiratory rate 28 breaths per minute and SpO2 91% on room air. Arterial blood gas shows a rising PaCO2 with a falling PaO2. There is no fasciculation, and pupils are now mid-sized and reactive. The MOST appropriate next step in management is: