Postoperative pain and rescue Analgesia required
Out of the total patients included in the study, 16 patients had a successful block. All patients with a successful block had a postoperative visual analogue scale score less than 4 in the initial 8h (see Figure 3A and Figure 3B). The average intraoperation sufentanil consumption was 10.8±3.33μg. Intraoperation sufentanil consumption between successful and unsuccessful blocks(P =0.2579) showed no difference. However, the mean time to 1st rescue analgesic was 9.2±2.71 h. The time to 1st rescue analgesic between successful and unsuccessful blocks(P =0.0024) was significantly different. The time to 1st analgesic request was moderately positively correlated with administered local anesthetic concentration, with the Spearman rank correlation r being 0.4865. This value of r was found to be statistically significant(P =0.0074)(see Figure 3C and D).