Journal of Tropical Medicine

Clinical Study

Acute Severe Anaphylaxis in Nepali Patients with Neurotoxic Snakebite Envenoming Treated with the VINS Polyvalent Antivenom

Table 3

Clinical notes on the eight patients with neurotoxic envenoming who died.


Patient	SCAD	Antivenom dose	Clinical description	Time to death in h	Commentary
Gender/
Age

#13 Male 25 y	N	H	30m after IV push developed generalised erythematous rash. Treated with SC adrenaline x 2 & IV hydrocortisone. Antivenom infusion restarted when rash resolved. ~1.5h later became restless & NS increased from 2 to 4. Treated with IV AV push but his NS remained stable at 4 (1h post push). Another hour later (i.e. 2h after IV push), he had a sudden cardiorespiratory arrest. Intubated, resuscitated successfully, was stable but drowsy and continued on mechanical ventilation. Frothy secretions in ET tube treated with atropine. NS became 0 but he was unable to be extubated. Developed ventilator associated pneumonia and treated with antibiotics. Laryngeal spasm occurred during tracheostomy resulting in death.	264	Had an initially mild ARA. His later restlessness is consistent more with worsening envenoming (increase in NS) than delayed recurrent ARA but the sudden CR arrest is consistent with delayed ARA due to the earlier IV antivenom pushes. Died of complications of snake bite, laryngeal spasm during tracheostomy.

#12 Male 11 y	Y	H	Generalised itching & urticaria developed 5m after IV push started. Treated correctly. IV adrenaline infusion started to cover rest of IV push & antivenom infusion when ARA had resolved. Later at T0+3.8h (2h after antivenom infusion stopped), patient became drowsy & restless with neurotoxicity score=0. Not treated for ARA. Sent to intensive care unit for monitoring. 10h later found gasping. Intubated & improved on oxygen. 6h later fall in SpO₂, sinus bradycardia, asystole, DC shocked and reverted to sinus tachycardia. Stable but 3.5h later another episode of sinus bradycardia and asystole. Resuscitation unsuccessful.	23.8	Initial itching and urticaria are typical features of mild ARA. Cause of later clinical picture was unclear but is consistent with delayed recurrent anaphylaxis.

#11 Male 6 y	N	L	Urticaria and unilateral eye oedema developed 5m after IV push started. Treated with x 2 SC adrenaline. ARA resolved. Antivenom restarted and stopped when neurotoxic signs disappeared. Patient later developed a hoarse voice (11h from T0, 8.5h since antivenom stopped) that worsened despite treatment with IM adrenaline and IV chlorphenamine. Dyspnoea and falling SpO₂. Intubation attempt failed because laryngeal oedema was severe. Patient was transferred but died in the ambulance.	13	Late laryngeal oedema is consistent with delayed recurrent ARA.

#10 Male 19 y	N	H	First indication of anaphylaxis was itching during antivenom infusion (30m after IV push). Antivenom stopped. Treated with chlorphenamine but IM adrenaline given 15m later when rash appeared. Antivenom restarted as rash was resolving. 1h 10m later while on antivenom infusion, patient became shocked with falling SpO₂ and development of angioedema. Resuscitated, intubated & transferred but died in the ambulance.	3.7	Clinical picture of ARA.

#9 Male 18 y	Y	L	Anaphylaxis manifested as mild urticaria 19m after IV push, treated with IM adrenaline & resolved. AV infusion restarted. Developed dyspnoea without wheezing & without an increase in NS (static at 2). Treated with oxygen but SpO₂ fell to 70%. Then AV stopped and treated appropriately for ARA but progressed rapidly to cardiorespiratory arrest & died despite resuscitation.	3.3	Decline in respiratory function without wheezing was thought initially to be envenoming related. Poor response to ARA treatment after fall in SpO₂ which was probably ARA related.

#8 Male 33 y	Y	H	Developed vomiting 15m after IV push followed by urticaria and dyspnoea with wheezing 5m later. Treated with salbutamol and ipratropium inhalations. No IM adrenaline given. Antivenom continued (NS=2). 40m later developed increased NS of 4 (IV AV push given) that, 20m later, increased to 6 associated with frothy secretions and muscle weakness (IV AV push given again). Became restless with gasping respirations, BP 90/60 & SpO₂ 80%, pulse fell from 140 to 55/m (sinus bradycardia, given IV atropine). Intubated, manually ventilated, then cardiac arrest and died despite resuscitation.	1.9	Clinical picture dominated by rapidly progressive envenoming despite treatment with antivenom pushes. Patient did not receive IM adrenaline for initial episode of mild anaphylaxis nor adrenaline cover for the IV pushes, nor IMAd for possible ARA.

#7 Female 5 y	Y	H	Presented with abdominal pain, vomiting, ptosis, tachypnoea (RR 40/m), tachycardia (120/m) and central cyanosis (SpO₂ 60%) treated with oxygen (SpO₂ rose to 90%) before antivenom. 15m after AV push & while on AVI had a respiratory arrest associated with sinus bradycardia (50/m). Immediate intubation was followed by a cardiac arrest. Resuscitated with IV adrenaline & 300 mL IV fluid bolus; AVI continued. Pulse detected by oximeter but no recordable blood pressure. Decision made to transfer to hospital. Second cardiac arrest (exact time not noted) followed by death despite resuscitation in ambulance.	1.3	Clinical picture dominated by poor respiratory status before antivenom associated with NS score of 3. Respiratory arrest after antivenom followed by cardiac arrest. Given the rapidity of the events, ARA may have contributed to the clinical picture.

#6 Male 51 y	Y	H	Rapid deterioration in cardiorespiratory function associated with sinus bradycardia and increasing NS. Culminated in a cardiorespiratory arrest and failed resuscitation. Treated for anaphylaxis and given IV antivenom push.	1.3	Treated for worsening envenoming and ARA. Clinical picture dominated by apparent worsening of envenoming that may have masked features of anaphylaxis. Died despite treatment for ARA

: time from the start of the intravenous push (T0) to the time death was certified. SCAd, subcutaneous adrenaline, IMAd: intramuscular adrenaline, SC: subcutaneous, IV: intravenous, IM: intramuscular.
h: hour, m: minute, y: years, NS: neurotoxicity score, AV: antivenom, AVI: antivenom infusion, ET: endotracheal tube, SpO₂: oxygen saturation, ARA: antivenom related anaphylaxis.