Reducing propofol waste during TIVA by pre-operative estimation of requirement: A single-center retrospective analysis.

OBJECTIVE

To evaluate whether estimating propofol requirement before surgery using a target-controlled infusion (TCI) model-based algorithm could reduce waste whilst maintaining workflow.

DESIGN

Retrospective cohort study with in silico TCI-TIVA simulations using the Eleveld model at fixed effect-site targets (Cet 2.5-4.0 μg.ml-1) or a Cet corresponding to an estimated BIS of 45 (ECBIS45). Monte-Carlo simulation examined uncertainty in surgical duration estimates.

SETTING

University tertiary care provider.

PATIENTS: 229 adult patients undergoing general anesthesia with conventional propofol TIVA with manually adjusted infusion rate.

MEASUREMENTS: Primary endpoint: predicted propofol amount for TCI and waste associated with three drawing-up strategies (50 ml vial only, 20 ml vial only, and vial combination based on estimated requirements). Secondary endpoint: relative number of syringe changes.

MAIN

RESULTS

Propofol requirements predicted using Cet 3.0 and ECBIS45 were similar to actual consumption. Algorithm-guided drawing-up produced significantly lower predicted waste than conventional TIVA practice (p < 0.0001, CI = -61.0 to -27.0 mg/procedure for Cet 3.0; p = 0.001, CI = -60.0 to -26.7 mg/procedure for ECBIS45), comparable to the 20 ml vial-only strategy but requiring fewer syringe changes. Waste remained significantly lower despite surgical duration estimation errors up to 20% for Cet 3.0 (p = 0.007) and 30% for ECBIS45 (p = 0.01).

CONCLUSIONS

Using the Eleveld TCI model to estimate pre-operative propofol requirements could significantly reduce waste and avoid excessive syringe changes, even when surgical duration is uncertain.