A Comparison of Oxycodone and Alfentanil in Intravenous Patient-Controlled Analgesia with a Time-Scheduled Decremental Infusion after Laparoscopic Cholecystectomy

Figure 5

Cumulative patient-controlled analgesia dose measured between 1 and 48 h after the operation. Means and standard deviation are shown. values were calculated by Mann-Whitney test. There were no significant differences between two groups ( value < 0.05). PCA: patient-controlled analgesia.