Sedation Following Cardiac Surgery: Evaluation of Alfentanil and Morphine in the Presence of a Computerized Closed Loop Arterial Pressure Controller

Abstract

Forty patients who had undergone coronary artery graft surgery and who required vasodilator therapy for postoperative hypertension were given infusions of either alfentanil or morphine together with bolus doses of midazolam for sedation and analgesia while ventilation was controlled artificially. Sodium nitroprusside (SNP) was administered to both groups using a computer-controlled closed loop system which adjusted the infusion rate to maintain a preset target arterial pressure. Target pressure +/- 5, 10, 15 and 20 mm Hg was maintained longer in the group receiving alfentanil. This group also required less SNP per hour. No difference was noted between the groups in the time taken to regain spontaneous ventilation and to extubation of the trachea, although the alfentanil group tended to be sedated more deeply during the infusion. The main advantage of alfentanil over morphine at doses used in this study was its superior ability to attenuate hypertensive responses to noxious stimuli, providing improved haemodynamic stability.

Efficacy of Remifentanil in Patients Undergoing Cardiac Surgery: A Systematic Review and Network Meta-Analysis

“…We identified 2,103 studies, including eight RCTs (691 participants) that were eligible for inclusion (Figure 1) (Table 1) [14][15][16][17][18][19][20][21].…”

“…These eight studies can be categorized as follows: a comparative study of remifentanil and fentanyl [17], an evaluation of sufentanil compared to remifentanil [14], a comparison between morphine and remifentanil [16], an assessment of morphine versus sufentanil [18], a study investigating the differences between morphine and fentanyl [15], two studies assessing the effects of alfentanil in relation to morphine [20,21], and a comparative study involving three treatment groups (remifentanil, fentanyl, and morphine) [19].…”

“…Table 2 shows the participants, interventions, comparisons, outcomes, and cohort characteristics of the included studies. All eight studies [14][15][16][17][18][19][20][21] reported the MV duration and four studies [14][15][16][17] reported the ICU length of stay. Five studies reported AEs [14,16,17,19,20].…”

“…We performed a subgroup analysis of six studies, excluding two that used concomitant sedative medications [14,16,[18][19][20][21]. We found that remifentanil does not reduce MV time compared to morphine, fentanyl, or sufentanil; it also seems to prolong the MV time compared to alfentanil (Appendix 3 Figure 9).…”

Closed-Loop Pharmacology in Anesthesia and Critical Care

“…42,43 Similarly, a closed-loop propofol infusion system was used to test different propofol infusion concentrations, 44 and a closed-loop muscle-relaxant infuser has been used to test the consumption rate of cisatracurium in different age groups. For example, 2 studies comparing anesthetics for sedation in the presence of a sodium nitroprusside infusion for blood pressure control (one comparing propofol to midazolam and the other morphine to alfentanil) used a closed-loop nitroprusside infusion system to ensure consistent dosing in both groups.…”