Cardiotoxicity secondary to fast sodium channel blockade:
- Give 1-2 mmol/kg IV until cardiovascular stability is achieved.
- Following stabilisation further doses may be required as guided by ECGs and blood gas estimations.
- If repeated doses are required it is easier and safer to intubate and hyperventilate to maintain a pH >7.5 – 7.55 than repeated boluses of sodium bicarbonate or an infusion (debatable efficacy).
Prevention of redistribution of salicylate to CNS:
- The pH must be maintained above 7.4 at all times. If the patient is critically ill with a severe metabolic acidosis they are usually intubated and the pH is maintained via hyperventilation. If they are not….
- Give sodium bicarbonate 2 mmol/kg IV bolus.
- Intubate, hyperventilate and recheck the VBG/ABG.
- Serum alkalinisation is maintained until definitive care with haemodialysis is achieved.
- Correct hypokalaemia.
- Give 1-2 mmol/kg sodium bicarbonate IV bolus.
- Commence an infusion of 150 mol sodium bicarbonate in 850 ml of 5% dextrose at 250 ml/hour.
- 20 mol of KCl may be added to maintain normokalaemia.
- Aim for a urinary pH > 7.5.
- Monitor serum bicarbonate and potassium every 4 hours.
- Bradberry SM, Thanacoody HK, Watt BE et al. Management of the cardiovascular complications of tricyclic antidepressant poisoning: role of sodium bicarbonate. Toxicological Reviews 2005; 24(3):195-204.
- Proudfoot AT, Krenzelok EP, Brent J et al. Does urine alkalinization increase salicylate elimination? If so, why? Toxicological Reviews 2003; 22(3):129-136.