Anaphylaxis from atracurium without skin manifestation
A 23-year-old female patient suffering from the chronic pancreatitis was posted for pancreatico-jejunostomy under general anesthesia. She did not have history of any other medical illness, no history of allergy; no history of previous surgery under anesthesia; her clinical examination and laboratory investigations were essentially normal. In the operating room, we secured an 18 G IV cannula, attached standard ASA (American Society of Anesthesiologists) monitors and recorded a baseline heart rate (HR) 85/min, blood pressure (BP) 115/74 mm Hg and a SpO2 of 97% on room air.\nInitially, she received 100 mcg fentanyl intravenously (I.V). After preoxygenation of 3 min, anesthesia was induced with 100 mg propofol and muscle relaxation for endotracheal (ET) intubation was facilitated by 75 mg succinylcholine. After confirmation of proper placement of ET tube by auscultation and EtCO2, ET tube was fixed at 18 cm. Anesthesia was maintained with 66% N2O, 33% O2 and 1% isoflurane. Three minutes after intubation, when respiratory efforts were seen, 15 mg atracurium was given I.V. Within 20-30 s after atracurium administration, we noticed a tachycardia of 140-160/min; BP was unrecordable and a peak airway pressure of 50 cm H2O with a SpO2 of 92%; however, we did not find any skin manifestations. On auscultation an essentially silent chest was found. We made a presumptive diagnosis of anaphylactic reaction; lungs were ventilated with 100% oxygen, intravenous 50 mcg adrenalin was administered in a dilution of 1:10000 and a rapid infusion of Ringer's lactate was initiated. After 1 min BP was 65/35 mm Hg, SpO2 - 94% and airway pressure was 40 cm H2O. Electrocardiography displayed sinus rhythm with a HR of 140/min. After another 2 min we repeated same IV dose of adrenaline and continued rapid infusion of Ringer's lactate. After 2 min of second dose of adrenalin, we recorded a BP of 85/55 mm Hg, SpO2 96%, peak airway pressure of 30 cm H2O, sinus tachycardia with a HR of 135/min. Wheezing was ausculated all over the lung fields. We then administered 10 mg chlorpheniramine and 200 mg hydrocortisone by slow IV injection. We decided to postpone the surgery for that day. After attainment of hemodynamic stability and resumption of spontaneous breathing activity, we reversed residual neuromuscular blockade by 2.5 mg neostigmine and 0.5 mg of glycopyrrolate. Trachea was extubated after 1 h of the incident and patient was kept on oxygen via face mask and monitored for the next 24 h in the post-anesthesia care unit (PACU). A post-operative chest X-ray done in the PACU was essentially normal. After 2 h of the event we collected blood sample for serum tryptase assay and after 4 weeks we arranged an intradermal test for atracurium. Serum tryptase value was 51.7 mcg/l and intradermal test for atracurium was found to be positive according to Société française d’anesthésie et réanimation criteria.[] However, it was negative for vecuronium and rocuronium. She underwent surgery uneventfully using the vecuronium as muscle relaxant 6 weeks later.