What is the management for a patient who develops signs of pulmonary congestion during antisnake venom (ASV) infusion?

Management of Pulmonary Congestion During Antisnake Venom Infusion

For a patient developing pulmonary congestion during antisnake venom (ASV) infusion, immediately stop the infusion and manage as a severe infusion reaction with respiratory support, antihistamines, corticosteroids, and careful monitoring.

Initial Management

1. Stop the ASV infusion immediately

   • Maintain IV access
   • Assess ABCs (Airway, Breathing, Circulation) 1

2. Airway management

   • Position patient in sitting position for respiratory distress 1
   • Administer oxygen 100% 1
   • If severe respiratory distress or airway compromise, prepare for intubation 1, 2

3. Medication administration

   • H1/H2 antihistamines: diphenhydramine 50 mg IV plus ranitidine 50 mg IV 1, 3
   • Corticosteroids: methylprednisolone 1-2 mg/kg IV every 6 hours 1, 3
   • If hypotension or signs of anaphylaxis are present:
     • Epinephrine: 0.2-0.5 mg (1 mg/mL) IM into lateral thigh, repeat every 5-15 minutes if needed 1
     • Consider epinephrine infusion if repeated doses required 1

4. Fluid management

   • IV fluids: Normal saline 0.9% or lactated Ringer's solution at high rate 1
   • For pulmonary edema specifically:
     • Position patient upright
     • Consider diuretics (furosemide)
     • Careful fluid management to avoid worsening pulmonary congestion

Monitoring and Secondary Management

1. Continuous monitoring

   • Vital signs (BP, HR, RR, SpO2)
   • Cardiac monitoring
   • Lung auscultation
   • Urine output

2. If hypotension persists despite epinephrine

   • Consider vasopressors:
     • Dopamine 400 mg in 500 mL, at 2-20 μg/kg/min 1
     • Vasopressin 25 U in 250 mL (0.1 U/mL), dose 0.01-0.04 U/min 1

3. For persistent bronchospasm

   • Consider salbutamol nebulization or IV infusion 1

ASV Readministration Considerations

After resolution of symptoms:

1. Risk assessment for continued ASV therapy

   • Severity of envenomation vs. reaction risk
   • Consider premedication before restarting ASV

2. If ASV must be continued 1, 4:

   • Premedicate with:
     • Subcutaneous adrenaline 0.25 mL (1:1000) immediately before ASV 4
     • Antihistamines and corticosteroids
   • Restart at 50% of previous rate and titrate slowly 1
   • Close monitoring for recurrence of symptoms

3. If severe reaction occurred:

   • Rechallenge is discouraged 1
   • Consider alternative management strategies for envenomation

Special Considerations

1. Pulmonary edema in ASV reactions

   • Can be non-cardiogenic in nature 5
   • May require prolonged ventilatory support
   • Monitor fluid balance carefully

2. Documentation

   • Document the reaction in detail including timing, symptoms, interventions, and response 1
   • Label patient as having ASV hypersensitivity

Post-Reaction Care

1. Close observation for 24 hours after severe reaction 1
2. Monitor for biphasic reactions which can occur hours after initial symptoms resolve 3
3. Consider transfer to higher level of care/ICU if severe reaction

Pulmonary congestion during ASV infusion represents a potentially life-threatening complication that requires immediate intervention. The reaction may represent anaphylaxis, cytokine release syndrome, or direct toxicity, but management principles remain similar with focus on respiratory support, symptom control, and careful consideration of risk/benefit for ASV continuation.