Anaphylaxis After Rocuronium During Induction
During induction of general anesthesia for a laparoscopic cholecystectomy in a 45-year-old woman, 90 seconds after IV rocuronium 0.6 mg/kg and fentanyl 100 mcg, the patient's blood pressure falls from 118/72 to 62/35 mmHg, heart rate rises from 78 to 132/min, and peak airway pressure rises from 18 to 34 cmH2O with no change in tube position. The capnography waveform becomes sloping, SpO2 falls from 99% to 88% on FiO2 1.0, and the skin shows urticaria over the chest and neck. The surgeon has just made the first incision. There is no history of allergy. Epinephrine 1 mg/mL and 0.1 mg/mL ampoules are in the drug cupboard; the anesthesiologist asks you to 'draw up adrenaline and get help' while she manages the airway.
1. Recognise the problem and prioritise your immediate actions, including drug preparation.
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Recognition. This is anaphylaxis, probably to rocuronium: acute hypotension, tachycardia, bronchospasm (peak pressure 18 → 34 cmH2O), falling SpO2 and urticaria after an IV induction agent. The sloping capnogram supports bronchospasm/obstruction. Do not wait for a rash to treat.
Immediate priorities.
- Call for help and activate the emergency team; tell the surgeon to stop surgery.
- Stop any likely trigger; keep the airway secure with 100% oxygen and check the tube, circuit and suction.
- Lay the patient supine with legs elevated; do not sit her up.
- Prepare epinephrine immediately - this is the priority drug.
- Start a rapid crystalloid bolus through a large-bore IV with a pressure bag.
- Attach ECG, SpO2, capnography and, if available, an arterial line; record times and vital signs every 1–2 minutes.
2. Calculate and describe the epinephrine doses and concentrations you would prepare for this adult, and state the rationale. Include fluid and adjunct measures.
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Epinephrine preparation and dosing for an adult.
- Bolus strength: draw 1 mg (1 mL of 1 mg/mL) into 9 mL saline → 10 mL of 100 micrograms/mL.
- IV bolus: 50–100 micrograms (0.5–1 mL) for grade III anaphylaxis with hypotension; repeat every 1–2 minutes and titrate to blood pressure. For grade IV/critical hypotension, 100–200 micrograms may be needed. If cardiac arrest occurs, give 1 mg IV (10 mL of 100 micrograms/mL).
- Infusion: 1 mg in 100 mL saline = 10 micrograms/mL. Start at about 0.05 micrograms/kg/min and titrate; for a 70 kg adult that is 3.5 micrograms/min, roughly 21 mL/hour, increasing to 0.2 micrograms/kg/min (about 84 mL/hour) if needed.
- Fluids: 20 mL/kg crystalloid rapidly, for example about 1.4–1.5 L for a 70–75 kg adult; repeat as needed.
- Adjuncts: hydrocortisone 200 mg IV and chlorphenamine 10 mg IV after epinephrine; nebulised salbutamol 2.5–5 mg for bronchospasm; consider glucagon in a beta-blocked patient and vasopressin in refractory shock.
Label every syringe, keep the ampoules, and never delay epinephrine while waiting for fluids or antihistamines.
3. How would you document and hand over this event, and what follow-up tests are needed?
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Documentation and follow-up.
- Time-stamped anaesthesia record: onset, vital signs, suspected trigger, every drug dose/route/time, fluids, response, who was called and when.
- Incident report per Kuwait MOH policy; inform the anaesthesia consultant, ICU and theatre team.
- Handover to ICU/PACU: anaphylaxis, epinephrine requirement, airway/bronchospasm, fluid balance, and whether a vasopressor infusion is running.
- Mast-cell tryptase samples: as soon as possible (within 1–2 hours) and again at 24 hours; document the exact sampling times.
- Allergy referral for skin testing; the patient should receive written information and a warning card. Record the allergy clearly in the file so future exposures are avoided.