Question 1

Why is the Done nomogram no longer recommended?

Accepted Answer

The Done nomogram was developed in 1960 from 159 children with acute aspirin overdose. It has never been validated for chronic toxicity, staggered overdose, or adults. It is unreliable for predicting severe outcome and does not incorporate acid-base status or CNS findings — the key determinants of outcome and dialysis need.

Question 2

How does chronic salicylate toxicity differ from acute overdose?

Accepted Answer

Chronic toxicity (common in older adults on daily aspirin) presents insidiously with confusion, dyspnoea, and non-cardiogenic pulmonary oedema. Serum salicylate levels may be only moderately elevated (300–600 mg/L). The mortality of chronic toxicity (25%) exceeds acute overdose (1–2%) because it is often unrecognised and patients are older with limited reserves.

Question 3

Can I use urinary alkalinisation in renal impairment?

Accepted Answer

Urinary alkalinisation requires adequate renal function (CrCl >30 mL/min) to be effective. In patients with renal impairment or those who fail to achieve urine pH ≥7.5 despite high-dose bicarbonate, early haemodialysis should be arranged. Hypokalaemia prevents effective alkalinisation — keep K+ ≥4 mmol/L.