bicarbonate in ASA poisoning

Q: Arterial pH of 7.55 is contraindicated for sodium bicarbonate in salicylate poisoning?

A) True

B) False

Answer: B

Urine alkalization is the mainstay of treatment in salicylate poisoning. Most of these patients present with respiratory alkalosis with higher PH. This should not deter a clinician from using bicarb. Said that close monitoring of PH is prudent to avoid severe alkalemia. The cut off point is around PH >7.60. The goal is to get urinary pH of 7.5 to 8. Urine alkalinization enhances salicylate excretion by many folds. 

Achieving euvolemia simultaneously enhances this excretion further. Said that diuretics don't increase salicylate excretion.

#toxicology

References:

1. Proudfoot AT, Krenzelok EP, Vale JA. Position Paper on urine alkalinization. J Toxicol Clin Toxicol 2004; 42:1.

2. Prescott LF, Balali-Mood M, Critchley JA, et al. Diuresis or urinary alkalinisation for salicylate poisoning? Br Med J (Clin Res Ed) 1982; 285:1383.

3. Vree TB, Van Ewijk-Beneken Kolmer EW, Verwey-Van Wissen CP, Hekster YA. Effect of urinary pH on the pharmacokinetics of salicylic acid, with its glycine and glucuronide conjugates in human. Int J Clin Pharmacol Ther 1994; 32:550.