Early Extubation After Cardiac Surgery: What Is the Appropriate Target Remifentanil Effect-Site Concentration?

Reducing the time to tracheal extubation and hence the duration of postoperative mechanical ventilation could lessen postoperative complications, improve patients' outcome, shorten the intensive care unit (ICU) stay, and reduce the cost of treatment.

Although high-dose opioid cardiac anesthesia has been shown to provide hemodynamic stability and adequate depth of anesthesia in response to nociceptive stimulation, it may cause delayed recovery and lengthening of the durations for postoperative ventilation support and (ICU length of stay.

The pharmacokinetic-based drug infusion systems, target-controlled infusion (TCI), can rapidly and easily enables changes and maintenance of a constant blood concentration of intravenous anesthetic drugs. We demonstrated that, the use of a TCI of sufentanil at effect-site concentrations (Ce) from 0.2 to 0.3 ng/mL during TCI of propofol anesthesia for valve surgery shortened the times to clinical recovery and extubation.

Remifentanil, a short-acting opioid-receptor agonist with a context-sensitive half-time of 3 to 5 minutes allowing rapid emergence from anesthesia, even after an infusion of several hours. Compared with sufentanil (0.03 to 0.04 µg/kg/min), the use of remifentanil (0.5 to 1.0 µg/kg/min) during propofol anesthesia improved recovery of pulmonary function and shortened postoperative hospital length of stay after coronary artery bypass grafting (CABG).

Furthermore, a TCI of remifentanil at Ce of 1.5-5.0 ng/ml is more effective than a constant-rate infusion in the inhibition of the stress response and the maintenance of the cardiac autonomic nervous system balance during off-pump CABG. Similarly, the lowest remifentanil Ce used in another study of explicit and implicit memory during cardiac surgery under TCI propofol were 2 to 4 ng/ml.