Key investigations

Asymptomatic patients with isopropyl alcohol poisoning do not require investigation.

Key investigations for symptomatic patients with isopropyl alcohol poisoning are:

  • serum electrolyte, urea and creatinine concentrations
  • blood gas analysis, including lactate concentration
  • blood glucose concentration

Isopropyl alcohol and its metabolite, acetone, increase the osmolar gap1; a raised osmolar gap may support the diagnosis of isopropyl alcohol poisoning. Calculation of the anion gap2 may also be helpful; a high anion gap acidosis should not occur with isopropyl alcohol ingestion alone.

Isopropyl alcohol is not detected by breath or serum ethanol assays. However, breath or serum ethanol concentration can confirm or exclude the presence of ethanol co-ingestion and is necessary in the calculation of the osmolar gap.

Urine and bedside ketone assays may not reliably detect acetone. The acetone metabolite of isopropyl alcohol can interfere with some creatinine assays causing a falsely elevated result.

1 Osmolar gap is calculated by: measured serum osmolality minus calculated serum osmolarity ([2 x serum sodium concentration] + serum urea concentration + blood glucose concentration + [1.2 x serum ethanol concentration]), all in mmol/LKhajuria 2005.Return
2 Anion gap is calculated by: [serum sodium concentration + serum potassium concentration] minus [serum chloride concentration + serum bicarbonate concentration].Return