Objective Insulin as continuous infusion is frequently used in critical care. Data on compatibilities are available for regular insulin but not for insulin aspart. The present study aimed at assessing the physical compatibility of insulin aspart with 47 drugs commonly used in intensive care units by simulated Y-site administration.

Methods The physical compatibility of insulin aspart 1 IU/mL in sodium chloride 0.9% and in dextrose 5% was evaluated by visual inspection over a 24 h period. Tested drugs were diluted in the same solvents or tested without dilution, based on standard practices. Tests were conducted in duplicates.

Results Insulin aspart was compatible over 24 h with 43 drugs over the 47 selected. Imipenem-cilastin, meropenem, esomeprazole and pantoprazole were compatible over a shorter period.

Conclusions Of the 47 drugs tested, only four were not physically compatible over 24 h. Our data will allow a switch from regular insulin to insulin aspart if needed.