Evaluation of Activated Clotting Times With a Heparin Reversal Protocol Designed to Conserve Protamine During Drug Shortages: A Retrospective, Cohort Study

To retrospectively evaluate a protamine conservation approach to heparin reversal implemented during times of critical shortages. This approach was aimed at maintaining access to cardiac surgical services. In-patient hospital setting. Eight hundred-one cardiac surgical patients>18 years old. Patients undergoing cardiac surgery who received >30,000 U of heparin were given a single fixed vial protamine dose of 250 mg or a standard 1 mg of protamine to 100 U of heparin ratio-based dose to reverse heparin. The primary endpoint was differences in post-reversal activated clotting times between the 2 groups. The secondary endpoint was differences in the number of protamine vials used between the 2 reversal strategies. The first activated clotting times values measured after initial protamine administration were not different between the Low Dose and Conventional Dose groups (122.3 s v 120.6 s, 1.47 s, 99% CI –1.47 to 4.94, p = 0.16). The total amount of protamine administered in the Low Dose group was less than that in the Conventional Dose group (–100.5 mg, 99% CI –110.0 to –91.0, p < 0.0001), as were the number of 250 mg vials used per case (–0.69, 99% CI –0.75 to –0.63, p < 0.0001). The mean initial protamine doses between groups were 250 mg and 352 mg, p < 0.0001. The mean protamine vials used were 1.33 v 2.02, p < 0.0001. When the calculations were based on 50 mg vials, the number of vials used per case in the Low Dose group was even less (–2.16, 99% CI –2.36 to –1.97, p < 0.0001).) Conservation measures regarding critical medications and supplies during times of shortages can maintain access to important services within a community.