The effect of ultrasound-guided intercostal nerve block, single-injection erector spinae plane block and multiple-injection paravertebral block on postoperative analgesia in thoracoscopic surgery: A randomized, double-blinded, clinical trial

Abstract

Study objective: The study was to determine the analgesic effect of ultrasound-guided intercostal nerve block (ICNB) and single-injection erector spinae plane block (ESPB) in comparison with multiple-injection paravertebral block (PVB) after thoracoscopic surgery.

Design: Randomized, controlled, double- blinded study.

Setting: Operating room, postoperative recovery room and ward.

Patients: Seventy-five patients, aged 18-75 years, ASA I-II and scheduled for elective thoracoscopic partial pulmonary resection surgery were enrolled in the study. Seventy-two patients were left for final analysis.

Interventions: Patients were randomly assigned into the three groups (PVB group, ICNB group or ESPB group). After anesthesia induction, a single anesthesiologist performed PVB at T5-T7 levels or ICNB at T4-T9 levels or ESPB at T5 level under ultrasound guidance using 20 ml of 0.375% ropivacaine. Patients were connected to the patient-controlled morphine analgesia device after surgery.

Measurements: Cumulative morphine consumption at 24 h postoperatively as primary outcome was compared. Visual analog scale pain scores at rest and while coughing at 0, 2, 4, 8, 24 and 48 h postoperatively, cumulative morphine consumption at other observed time and rescue analgesia requirement were also recorded.

Main results: There was a significant difference in median [interquartile range, IQR] morphine consumption at 24 h postoperatively among the three groups (PVB, 10.5 [9-15] mg; ICNB, 18 [13.5-22.1] mg; ESPB, 22 [15-25.1] mg; p = 0.000). This difference was statistically significant for PVB group vs ESPB group (median difference, -7.5; 95% confidence interval [CI], -12 to -4.5; p = 0.000) and PVB group vs ICNB group (median difference, -6; 95% CI, -9 to -3; p = 0.001), but not for ICNB vs ESPB (median difference, -3; 95% CI, -6 to 1.5; p = 0.192). PVB group had significantly lower VAS scores at rest and while coughing than ESPB group at 0, 2, 4, 8 h postoperatively and than ICNB group at 8 h postoperatively. There was no significant difference in the VAS scores between ICNB group and ESPB group at all time. Median VAS scores at rest and while coughing at all time were low (<4) in all groups. More rescue analgesia was needed in ESPB group during 48 postoperative hours (PVB vs ICNB vs ESPB; 13% vs 29% vs 46%; p < 0.05).

Conclusions: Ultrasound-guided multiple-injection PVB provided superior analgesia to ICNB and single-injection ESPB, while ICNB and single-injection ESPB were equally effective in reducing pain after thoracoscopic surgery.

Keywords: Erector spinae plane block; Intercostal nerve block; Paravertebral block; Postoperative pain; Thoracoscopic surgery; Ultrasound guidance.