Evaluation of the Erector spinae plane block for postoperative analgesia in laparoscopic ventral hernia repair: a randomized placebo controlled trial.

BACKGROUND: The Erector spinae plane block (ESPB) reduces postoperative pain after several types of abdominal laparoscopic surgeries. There is sparse data on the effect of ESPB in laparoscopic ventral hernia repair. The purpose of this study was to test the postoperative analgesic efficacy of an ESPB for this procedure. METHODS: In this prospective, double-blind, randomized controlled study, adult patients undergoing laparoscopic ventral hernia repair were randomly assigned to either bilateral preoperative ESPB with catheters at the level of Th7 (2 × 30 ml of either 2.5 mg/ml ropivacaine or saline), with postoperative catheter top ups every 6 h for 24 h. The primary outcome was rescue opioid consumption during the first hour postoperatively. Secondary outcomes were total opioid consumption at 4 h and 24 h, pain scores, nausea, sedation, as well as Quality of Recovery 15 (QoR-15) and the EuroQol-5 Dimensions (EQ-5D-5L) during the first week. RESULTS: In total, 64 patients were included in the primary outcome measure. There was no significant difference in rescue opioid consumption (oral morphine equivalents (OME)) at one hour postoperatively, with the ESPB group 26.9 ± 17.1 mg versus 32.4 ± 24.3 mg (mean ± SD) in the placebo group (p= 0.27). There were no significant differences concerning the secondary outcomes during the seven-day observation period. Seven patients received a rescue block postoperatively, providing analgesia in five patients. CONCLUSION: We found no difference in measured outcomes between ESPB and placebo in laparoscopic ventral hernia repair. Future studies may evaluate whether a block performed using higher concentration and/or at a different thoracic level provides more analgesic efficacy. TRIAL REGISTRATION: NCT04438369 ; 18/06/2020. .

Dorsal root ganglion: a key to understanding the therapeutic effects of the erector spinae plane (ESP) and other intertransverse process blocks?

Since its description in 2016, the erector spinae plane block (ESPB) has become a widely employed regional anesthetic technique and kindled interest in a range of related techniques, collectively termed intertransverse process blocks. There has been ongoing controversy over mechanism of action of the ESPB, mainly due to incongruities between results of cutaneous sensory testing, clinical efficacy studies, and investigations into the neural structures that are reached by injected local anesthetic (LA). This paper reviews the spread of LA to the paravertebral and epidural space and the cutaneous anesthesia in ESPB, with specific emphasis on the dorsal root ganglion (DRG). We hypothesize that the DRG, due to its unique and complex microarchitecture, represents a key therapeutic target for modulation of nociceptive signaling in regional anesthesia. This paper discusses how the anatomical and physiological characteristics of the DRG may be one of the factors underpinning the clinical analgesia observed in ESPB and other intertransverse process blocks.

Efficacy of a TAP block versus an anterior QLB for laparoscopic inguinal hernia repair: A randomised controlled trial.

BACKGROUND: Both the transversus abdominis plane (TAP) block and the anterior quadratus lumborum block (QLB) have been shown effective in reducing postoperative pain after laparoscopic inguinal hernia repair. Our hypothesis was that there is no difference in analgesic effect between the two blocks for this procedure. METHODS: In this prospective, double-blind, randomised controlled study, 60 adult patients undergoing laparoscopic inguinal hernia repair were equally randomly assigned to either a preoperative TAP block or an anterior QLB. The primary outcome was oral morphine equivalent (OME) consumption at 4 h postoperatively. Secondary outcomes were OME consumption at 24, 48 h and 7 days, pain scores at rest and when coughing, nausea, and level of sedation measured at 1, 2, 3, 24, and 48 h and 7 days postoperatively. RESULTS: Fifty-three patients completed the study. There was no significant difference in OME consumption at 4 h postoperatively, TAP group (10.3 ± 7.85 mg) (mean ± SD) versus the anterior QLB group (10.9 ± 10.85 mg) (p = .713). The pain scores were similar at rest and when coughing during the 7 day observation period, as were the level of sedation and incidence of nausea. There were no cases of serious side-effects or muscle weakness of the thigh on the same side as the block. CONCLUSION: There is no difference in OME consumption, pain, nausea or sedation between the TAP and the anterior QLB. Thus, the choice between the two blocks in a clinical setting of laparoscopic inguinal hernia repair should be based on other aspects, such as skills, practicalities, and potential risks.

Spread of local anesthetics after erector spinae plane block: an MRI study in healthy volunteers.

BACKGROUND: Erector spinae plane block (ESPB) is a truncal fascial block with a disputed mechanism and anatomical site of effect. This study aimed to perform a one-sided ESPB and use MRI to investigate the spread of the local anesthetic (LA) and the corresponding cutaneous loss of sensation to pinprick and cold. METHODS: Ten volunteers received a right-sided ESPB at the level of the seventh thoracic vertebra (Th7), consisting of 30 mL 2.5 mg/mL ropivacaine with 0.3 mL gadolinium. The primary outcome was the evaluation of the spread of LA on MRI 1-hour postblock. The secondary outcome was the loss of sensation to cold and pinprick 30-50 min after the block was performed. RESULTS: All volunteers had a spread of LA on MRI in the erector spinae muscles and to the intercostal space. 9/10 had spread to the paravertebral space and 8/10 had spread to the neural foramina. 4/10 volunteers had spread to the epidural space. One volunteer had extensive epidural spread as well as contralateral epidural and foraminal spread. Four volunteers had a loss of sensation both posterior and anterior to the midaxillary line, while six volunteers had a loss of sensation only on the posterior side. CONCLUSION: We found that LA consistently spreads to the intercostal space, the paravertebral space, and the neural foramina after an ESPB. Epidural spread was evident in four volunteers. Sensory testing 30-50 min after an ESPB shows highly variable results, and generally under-represents what could be expected from the visualized spread on MRI 60 min after block performance. TRIAL REGISTRATION NUMBER: NCT05012332.

Anterior quadratus lumborum block for ambulatory laparoscopic cholecystectomy: a randomized controlled trial.

AIM: To explore the effects of an anterior quadratus lumborum block (QLB) on opioid consumption, pain, nausea, and vomiting (PONV) after ambulatory laparoscopic cholecystectomy. METHODS: This randomized controlled study recruited 70 patients scheduled for ambulatory laparoscopic cholecystectomy from January 2018 to March 2019. The participants were randomly allocated to one of the following groups: 1) anterior QLB (n=25) with preoperative ropivacaine 3.75 mg/mL, 20 mL bilaterally; 2) placebo QLB (n=22) with preoperative isotonic saline, 20 mL bilaterally; and 3) controls (n=23) given only standard intravenous and oral analgesia. The primary endpoint was opioid analgesic consumption. The secondary endpoints were pain (numeric rating scale 0-10) and PONV (scale 0-3, where 0=no PONV and 3=severe PONV). Assessments were made up to 48 hours postoperatively. RESULTS: The groups did not significantly differ in opioids consumption and reported pain at 1, 2, 24, and 48 hours postoperatively. PONV in the QLB group was lower than in the placebo and control groups. CONCLUSION: Preoperative anterior QLB for laparoscopic cholecystectomy did not affect postoperative opioid requirements and pain. However, anterior QLB may decrease PONV.