Figure 3.

Number of bolus deliveries (A) and the number of bolus attempts (B) during the first 36 h after surgery. Data are expressed as mean ± standard deviation. ^†P < 0.01, ^††P < 0.05 vs. the IV-PCA group (Bonferroni corrected); *P < 0.01, **P < 0.05 vs. the IV-PCA group (Bonferroni corrected). E-PCA, epidural patient-controlled analgesia; dIV-PCA, dexmedetomidine in combination with fentanyl-based intravenous patient-controlled analgesia; IV-PCA, intravenous patient-controlled analgesia