Effect of the modality selected and the target concentration on the infusion rate and dosage of remifentanil during target controlled infusion of remifentanil: simulation study

ABSTRACT

BACKGROUND:Administration of a rapid or large dose of remifentanil (>1.0microg/kg for 30?60 s) should be avoided due to its association with side effects such as muscle rigidity. The present study determined the infusion rate and dosage of remifentanil administered using target-controlled infusion (TCI) varies with the modality selected and the target concentration. METHODS: Data including the age, sex, weight, and height of 10 patients undergoing elective surgery in a university hospital were randomly used for a 3-min simulation of TCI-remifentanil Minto model. In every simulation, TCI targeting both plasma (Cp) and the effect-site (Ce) was performed repeatedly with varying target concentrations (2, 3, 5, 10, and 20 ng/ml). The rate of administration and the cumulative dosages of remifentanil (per min) in all of the TCI simulations were recorded and analyzed. RESULTS: The rates of Ce TCI were significantly greater than those of Cp TCI using the same concentration. The cumulative dosage in the first-minute TCI simulation with Cp 20 ng/ml, and Ce 3, 5, 10, 20 ng/ml exceeded 1.0microg/kg/min. CONCLUSIONS: The target concentration and the infusion modality should be selected carefully to avoid rapid infusion and an overdose of remifentanil.