1. A comparison has been made between alkaline mannitol diuresis and alkaline glucose diuresis in the treatment of salicylate poisoning during an 8 hr period.
2. Mannitol gave a higher rate of urine flow, but there was no significant difference in the rate of salicylate excretion.
3. Serum levels of sodium, potassium and calcium fell in both groups, mainly during the first 2 hr. The mean fall in serum sodium was greater (21·4 mEq/l compared with 10·0 mEq/l) and that in serum potassium less (0·6 mEq/l compared with 1·5 mEq/l) in patients who received mannitol than in those who did not.
4. All serum electrolyte values had returned to normal within 24 hr of the end of the treatment period.
5. Acid—base changes occurring during treatment are described.
6. No adverse clinical features were seen in either treatment group.
7. Syrup of ipecacuanha was used to induce emesis. The mean recovery of salicylate in the vomitus was 38% of the apparent total ingested. The variability in recovery (0–81%) was not related to the delay between ingestion and vomiting.
8. It is concluded that mannitol does not increase the excretion of salicylate. It maintains good urinary excretion, thereby increasing the safety of the procedure. It is associated with a smaller fall in serum potassium and permits rapid removal of salicylate for a smaller rise in serum pH than does forced alkaline diuresis alone.