Comparison of the Efficacy between Dexmedetomidine plus Morphine Patient-Controlled Analgesia (PCA) and Morphine Patient-Controlled Analgesia (PCA) Alone for Pain Control in Postoperative Valvular Heart Surgery

Abstract

Introduction: Postoperative pain after valvular heart
surgery is moderate to severe pain. Morphine was
generally used, but it has undesirable dose-related side
effects. Dexmedetomidine an analgesic adjuvant may
reduce morphine used.
Objectives: To compared the efficacy between
dexmedetomidine plus morphine patient-controlled
analgesia (PCA) and morphine PCA alone postoperatively.
Methods: This randomized controlled trial assigned
32 patients undergoing valvular heart disease into
2 groups included D group (dexmedetomidine; n=16)
received dexmedetomidine after extubation with loading
dose 1 mcg/kg then infused 0.3 mcg/kg/h and P group
(placebo; n= 16); combined with PCA morphine
postoperatively in both groups. Postoperative cumulative
morphine consumption at 24 and 48 h and pain scores at
time points of 0, 6, 12, 24 and 48 h were recorded.
Results: The cumulative morphine consumption was
not statistically significant in both groups within 48 h
postoperatively (D vs. P group = 16.94 ± 7.56 mg vs.
15.00 ± 6.46 mg, 95%CI -2.05-2.55, p-value = 0.826).
The D group had numeric rating scale (NRS) value at rest
lower than P group significantly at 12 h postoperative

(0.06 ± 0.25 and 0.88 ± 1.50, mean different = -0.81,
95%CI -1.59 to -0.04, p-value = 0.041) and 24 h
postoperative (0 and 0.44 ± 0.81, mean different = -0.44,
95%CI -0.85 to -0.02, p-value = 0.040). The NRS at rest
in the other time and on movement in any time did not
different between groups.
Conclusion: Dexmedetomidine 0.3 mcg/kg/h cannot
decrease cumulative morphine consumption within 48 h
postoperatively as an adjunct to morphine PCA.