Korean J Anesthesiol for postoperative side-effects. Nausea (0 = no nausea; 1 = mild; 2 = moderate; 3 = severe) of at least 1 and sedation (0 = alert; 1 = drowsy; 2 = sleeping, easy to arouse; 3 = sleeping, difficult to arouse) of at least 2 were included. At the time of patient discharge, the patient was directly surveyed for their satisfaction Lee, et al. value < 0.05 was considered statistically significant. Results There were no statistical differences between the two groups scores (0 = very unsatisfied, 100 = very satisfied). The length in regards to age, gender, BMI, ASA class, and anesthetic time of the hospital stay, additional use of rescue antiemetics and (Table 1). There were no statistical differences between Group analgesics were recorded. With severe nausea and vomiting, 10 PCB (45.2) and Group IVPCA (54.0) in postoperative pain scores mg of metoclopramide was administered and if the VNRS was 6 hours after the surgery; however, 24 hours and 48 hours after more than 40 mm, 90 mg of diclofenac was administered. The the surgery, the postoperative pain scores were significantly administration of the two drugs was recorded as well. lower in Group PCB (29.5, 16.0) than Group IVPCA (43.5, 28.5) Using a VNRS of 20 mm as the basis, significance level (Fig. 2). (α) as 0.05, and the power as 0.8, the sample size was set at None of the patients experienced serious complications such 19 patients per group. When considering the drop rate, the as hypoventilation, nerve damage or hemorrhaging at the site number of patients per group was set at 20. Statistical analysis of PCB. There were significantly more frequent incidences of was conducted using SPSS for Window version 12. 0, and all nausea and sedation in Group IVPCA than in Group PCB. There the quantative data was analyzed using ANOVA. Side-effects were no statistical differences in vomiting or voiding difficulty were analyzed using the Chi-square test. For post-hoc testing, (Table 2). Tukey and Dunnett’s T3 were used. Quantative data was shown There were no statistical differences in satisfaction scores or as mean ± SD, and the remaining was shown as numbers. A P the length of the hospital stay between the two groups. Rescue Table 1. Demographic and Perioperative Data Sex (M/F) Age (yr) Height (cm) Weight (kg) BMI ASA physical status I/II Ane. time (Min) IVPCA (n = 20) 4/16 63.9 ± 8.8 155.6 ± 6.9 64.9 ± 8.3 26.7 ± 2.7 5/15 161.2 ± 17.2 PCB (n = 20) 4/16 66.1 ± 7.8 156.4 ± 7.3 65.5 ± 9.9 26.1 ± 3.0 4/16 162.2 ± 15.0 All values except sex and ASA physical status are expressed as mean ± SD. Sex and ASA physical status are expressed as the number of patients. BMI: body mass index. ASA: American Society of Anesthesiologists. Ane. time: anesthetic time. Fig. 2. A comparison of pain scores according to groups using a verbal numeric rating scale (VNRS) for postoperative pain in Group IVPCA and Group PCB according to time. *P < 0.05 compared to Group IVPCA. www.ekja.org antiemetics and sedatives were used more frequently in Group IVPCA than in Group PCB, but no statistical differences were observed (Table 3). Discussion Postoperative pain of TKA causes the reflexive constriction of the quadratus femoris muscle, which results in increased pain and damage to the muscle function. These effects hinder Table 2. Incidences of Side Effects According to Groups IVPCA (n = 20) PCB (n = 20) Nausea Vomiting Voiding difficlty Sedation Respiratory depression Hematoma Nerve injury 10 (50) 5 (25) 2 (10) 7 (35) 0 (0) - - Values are expressed as the number (%) of patients. *P < 0.05 compared to Group IVPCA. Table 3. Comparison of the Length of the Hospital Stay, Satisfaction Score, Antiemetics and Analgesics According to Groups Length of hospital stay (days) Satisfaction score (0-100) Rescue antiemetics Rescue analgesics 17.7 ± 5.1 74 ± 14 7 (35) 14 (70) 17.3 ± 4.0 81 ± 12 3 (15) 10 (50) The length of hospital stay and the satisfaction scores are expressed as mean ± SD. Rescue antiemetics and analgesics are expressed as the number of patients (%). IVPCA (n = 20) PCB (n = 20) 4 (20)* 2 (10) 2 (10) 1 (5)* 0 (0) 0 (0) 0 (0) 49