Anesthesia for total knee replacement Vol. 62, No. 5, May 2012 “strongest pain imaginable”, and postoperative side effects preparation time, duration of surgery, and total anesthetic time, (dizziness, sedation, postoperative nausea/vomiting, and though actual age was higher in the FSNB group (67.4 versus pruritus) were assessed simultaneously 1, 2, 6, 12, 24, and 48 71.8, respectively, P = 0.018) (Table 1). hours after surgery. Intraoperatively, the number of patients who required addi- Statistical analyses were performed using SPSS software tional analgesia or sedation using intravenous administration (version 14.0, SPSS Inc, IL, USA). All data are expressed mean ± of ketorolac, fentanyl, midazolam, and bolus propofol was SEM or number of patients. Student two tailed t-tests were used significantly higher in the FSNB group compared with the CSE to compare the rate of satisfaction with the surgical anesthesia group. However, there were no significant differences between and the postoperative analgesia and other quantitative variables the number of patients requiring propofol infusion, antiemetics, such as age, height, weight, a dose of medications, durations, and antihypertensives, except nicardipine. No severe events, and complete resolution time between the two groups. The such as systemic toxicity of local anesthetics, total spinal willingness to recommend the same surgical anesthesia and anesthesia, or cardiac arrest were reported in any of the patient. postoperative analgesia to others, intraoperative and post- There was no difference in frequency of complications between operative side effects, the frequency of use of intraoperative the two groups (P > 0.05). Nevertheless, hypotension (eight medications, and other categorical variables were analyzed patients in the CSE group and four patients in the FSNB group) using the Pearson’s Chi-square test. The statistical significance and bradycardia (four patients in the CSE group and one patient of differences between the VAS scores at the different time in the FSNB group) occurred in each group. The incidences of points was tested, first using repeated-measures analysis of each side effect for the postoperative 48 hours are presented in variance, and, then, with post hoc Student two tailed t-tests Table 2. No patient had pruritus or sedation postoperatively. where appropriate, using the Bonferroni correction for multiple No significant differences of the incidences of dizziness and comparisons. A significant difference was acknowledged if the postoperative nausea/vomiting were found between the two probability of a type 1 error was < 5% (i.e., P < 0.05). Results Eighty-four patients were included in this study in which two patients in the CSE group and two patients in the FSNB group required general anesthesia because of failure of the anesthetic technique. These four patients were excluded from the study. Thus, the success of providing adequate anesthesia was 95.2% (40 patients) in the two groups. There were no significant differences between the two groups in terms of demographic data (sex, weight, and height), American Society of Anesthesiologists (ASA) physical status, site of surgery, CSE group (n = 40) 1/38/0 67.4 ± 1.3 4/36 57.3 ± 1.5 154.9 ± 1.2 24/16 9.7 ± 1.0 124.5 ± 4.7 154.4 ± 3.2 FSNB group (n = 40) 2/36/2 71.8 ± 1.3* 3/37 55.8 ± 1.7 153.4 ± 1.5 25/15 11.6 ± 1.3 135 ± 5.9 158.6 ± 2.3 Table 1. Demographic Data ASA PS (I/II/III) Age (yr) Sex (M/F) Body weight (kg) Height (cm) Site of surgery (right/left) Preparation time (min) Duration of surgery (min) Total anesthetic time (min) 450 Values are mean ± SEM or number of patients. CSE: combined spinal epidural anesthesia, FSNB: femoral/sciatic nerve block with lateral femoral cutaneous nerve block, ASA PS: American Society of Anesthesiologists physical status. *P < 0.05 compared with CSE group. groups. Complete resolution time, duration of IV PCA use, and remaining amount of IV PCA were comparable between the two groups (Table 3). No difference was noted between the groups in terms of Table 2. Postoperative Incidence of Side Effects PO 1 hr PO 2 hr PO 6 hr PO 12 hr PO 24 hr PO 48 hr Dizziness PONV CSE (n = 40) 2 (5.0) 2 (5.0) 6 (15.0) 2 (5.0) 0 (0.0) 1 (2.5) FSNB (n = 40) 0 (0.0) 0 (0.0) 5 (12.5) 1 (2.5) 1 (2.5) 1 (2.5) CSE (n = 40) 2 (5.0) 6 (15.0) 3 (7.5) 3 (7.5) 4 (10.0) 0 (0.0) FSNB (n = 40) 1 (2.5) 5 (12.5) 1 (2.5) 3 (7.5) 4 (10.0) 0 (0.0) Values are number of patients (percentage). PONV: postoperative nausea and vomiting, CSE: combined spinal epidural anesthesia, FSNB: femoral/sciatic nerve block with lateral femoral cutaneous nerve block, PO n hr: nth postoperative hour. Table 3. The Data of Intravenous Patient-Controlled Analgesia Duration of IV PCA use (min) Remaining amount of IV PCA (ml) Complete resolution time (min) 3,007.1 ± 153.5 3,596.8 ± 254.3 7.5 ± 3.9 1.4 ± 0.8 296.9 ± 15.7 264.5 ± 28.4 Values are mean ±SEM. CSE: combined spinal epidural anesthesia, FSNB: femoral/sciatic nerve block with lateral femoral cutaneous nerve block, IV PCA: intravenous patient-controlled analgesia. CSE group (n = 40) FSNB group (n = 40) www.ekja.org