What is the order for pralidoxime (Pam) infusion in the treatment of organophosphate poisoning?

Pralidoxime (PAM) Infusion Protocol for Organophosphate Poisoning

For organophosphate poisoning, administer pralidoxime as a 1-2 gram IV loading dose over 15-30 minutes, followed by a continuous infusion of 400-600 mg/hour (adult) or 10-20 mg/kg/hour (pediatric) for at least 24-48 hours. 1, 2, 3

Initial Assessment and Stabilization

• Ensure proper personal protective equipment (PPE) before patient contact
• Decontaminate patient (remove clothing, wash skin with soap and water)
• Assess for SLUDGE syndrome (Salivation, Lacrimation, Urination, Defecation, GI upset, Emesis)
• Secure airway, breathing, and circulation

Medication Protocol

Step 1: Atropine Administration (First Priority)

• Adults: 1-2 mg IV, doubled every 5 minutes until atropinization achieved
• Pediatrics: 0.02 mg/kg IV, doubled every 5 minutes
• Target endpoints: Clear lungs, HR >80/min, SBP >80 mmHg, dry secretions
• Maintenance: 10-20% of total loading dose per hour (up to 2 mg/hr)

Step 2: Pralidoxime Administration

1. Loading Dose:

   • Adults: 1-2 grams IV over 15-30 minutes 1, 2
   • Pediatrics: 20-50 mg/kg IV 1

2. Continuous Infusion (Preferred Method):

   • Adults: 400-600 mg/hour IV 1, 3
   • Pediatrics: 10-20 mg/kg/hour IV 1
   • Duration: Continue for at least 24-48 hours 2, 3

3. Solution Preparation:

   • Dilute in normal saline or D5W
   • Maximum concentration should not exceed 20 mg/mL 3

Monitoring Parameters

• Vital signs every 15 minutes until stable
• Respiratory status and secretions
• Cholinesterase levels (if available)
• Signs of atropine toxicity (confusion, hyperthermia, urinary retention)
• Serum pralidoxime levels (therapeutic target >4 μg/mL) 3, 4

Clinical Pearls

• Continuous infusion maintains therapeutic pralidoxime levels better than intermittent dosing 3, 4, 5
• After a single 1g bolus, pralidoxime levels fall below therapeutic threshold (4 μg/mL) within 1.5 hours 3, 4
• Early administration of pralidoxime is crucial before "aging" of the acetylcholinesterase-organophosphate complex occurs 2
• Pralidoxime primarily addresses nicotinic effects (muscle weakness, fasciculations), while atropine addresses muscarinic effects 2

Cautions

• Some studies question the efficacy of pralidoxime in improving mortality outcomes 6
• Effectiveness may depend on plasma concentrations of both pralidoxime and the specific organophosphate 7
• Higher pralidoxime concentrations may be needed when organophosphate levels remain elevated 7
• Avoid succinylcholine for intubation as it may cause prolonged paralysis 2

The continuous infusion approach is preferred over intermittent dosing as it maintains therapeutic levels more consistently, which is critical for effective reactivation of acetylcholinesterase in severe organophosphate poisoning 3, 4, 5.