JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD Pharm. D IV Year CLINICAL TOXICOLOGY Previous Question Paper (June/July - 2022 - R08)

Management of respiratory insufficiency in acute poisoning focuses on maintaining airway patency and ensuring adequate gas exchange. The primary steps include:

1. Airway Assessment: Clear the airway of secretions, vomitus, or foreign bodies. Use maneuvers like the head-tilt/chin-lift or jaw-thrust to prevent tongue obstruction.
2. Oxygenation: Administer supplemental oxygen via nasal cannula or non-rebreather mask to maintain oxygen saturation above 94%.
3. Ventilatory Support: If the patient exhibits hypoventilation (respiratory rate < 8-10 breaths/min), apnea, or severe hypoxia, initiate bag-valve-mask ventilation.
4. Endotracheal Intubation: Perform rapid sequence intubation (RSI) if the patient has a depressed level of consciousness (GCS < 8), inability to protect the airway, or persistent respiratory failure.
5. Specific Antidotes: Administer specific antidotes if the cause is known, such as naloxone for opioid-induced respiratory depression or flumazenil for benzodiazepine toxicity (with caution).
6. Monitoring: Continuous pulse oximetry and arterial blood gas (ABG) analysis are essential to monitor pH, PaCO2, and PaO2 levels.

Management of cardiac arrhythmias in acute poisoning requires immediate hemodynamic stabilization and identification of the toxic agent. The approach includes:

1. Hemodynamic Assessment: Check for pulses, blood pressure, and perfusion status. If the patient is unstable, initiate Advanced Cardiac Life Support (ACLS) protocols immediately.
2. Continuous Monitoring: Place the patient on a cardiac monitor to assess rhythm, QRS duration, and QTc interval.
3. Correction of Metabolic Abnormalities: Address electrolyte imbalances (e.g., hypokalemia, hypomagnesemia) and acid-base disturbances (e.g., metabolic acidosis), which are common triggers for arrhythmias in poisoning.
4. Pharmacological Management: Use specific agents based on the arrhythmia type:
   • For sodium channel blocker toxicity (e.g., tricyclic antidepressants), administer sodium bicarbonate to narrow the QRS complex.
   • For beta-blocker or calcium channel blocker toxicity, use glucagon, high-dose insulin-euglycemic therapy, or calcium salts.
   • For tachyarrhythmias, use standard antiarrhythmics, though caution is required as many can worsen toxicity.
5. Electrical Therapy: Perform synchronized cardioversion for unstable tachyarrhythmias or defibrillation for ventricular fibrillation.
6. Advanced Support: In cases of refractory shock or severe conduction disturbances, consider transvenous pacing or extracorporeal membrane oxygenation (ECMO).