Anatomy of the thoracic paravertebral space: 3D micro-CT findings and their clinical implications for nerve blockade

Ultrasound-guided mid point-transverse process to pleura block versus thoracic paravertebral block in pediatric open-heart surgery: A randomized controlled non-inferiority study

STUDY OBJECTIVE

The mid point-transverse process to pleura block (MTPB) is a new variant of thoracic paravertebral block (TPVB). This study aimed to compare TPVB and MTPB with respect to intraoperative attenuation of the hemodynamic stress response to surgery and postoperative analgesia in pediatric open heart surgery with midline sternotomy.

DESIGN

A single-center, randomized, controlled, double-blind, non-inferiority study.

SETTING

Tertiary care children's university hospital.

PATIENTS

We recruited 83 children aged 2-12 years of both sexes with American Society of Anesthesiologists (ASA) physical status class II who were scheduled for elective open cardiac surgeries with midline sternotomy for the repair of simple noncyanotic congenital heart defects.

INTERVENTIONS

Eligible participants were randomized into either the TPVB or MTPB groups at a ratio of 1:1. In the TPVB group, patients were bilaterally injected with 0.4 ml/kg of 0.25% bupivacaine in the paravertebral space at T4 and T5. In the MTPB group, patients were bilaterally injected with 0.4 ml/kg of 0.25% bupivacaine mid-transverse process and pleura just posterior to superior costotransverse ligament at the level of T4 and T5.

MEASUREMENTS

The primary outcome was the hemodynamic responses to sternotomy incision, including heart rate (HR) and invasive mean arterial pressure (MAP), recorded before and after the induction of anesthesia, after skin incision, after sternotomy, 15 min after cardiopulmonary bypass (CPB), and after the closure of the sternum. The secondary outcomes were time needed to perform the bilateral block, intraoperative fentanyl consumption, postoperative fentanyl consumption, modified objective pain score (MOPS) measured at 1, 2, 6, 12, 18, and 24 h after extubation, extubation time, intensive care unit (ICU) discharge time, and the incidence of non-surgical complications (postoperative pruritus, postoperative vomiting, pneumothorax, hematoma or local anesthetic toxicity).

MAIN RESULTS

There were no significant differences in HR and MAP in the TPVB group compared with the MTPB group at the following time points: baseline, after induction, after skin incision, after sternotomy, 15 min after CPB, and after sternal closure. Intergroup comparisons of HR and MAP did not reveal significant differences between the groups. The median (IQR) time needed to perform bilateral MTPB (7[6-8] min) was significantly (p < 0.001) shorter than that of TPVB (12[10-13] min). Intraoperative fentanyl consumption and fentanyl consumption in the first postoperative 24 h after extubation were similar in the TPVB and MTPB groups (4[2-4] vs 4[2-4] and 4.66 ± 0.649 vs 4.88 ± 1.082 μg/kg), respectively. Extubation time and ICU discharge time were comparable in the TPVB and MTPB groups (2[1-3] vs 2[1-3] h and 21.2 ± 2.5 vs 20.8 ± 2.6 h), respectively. Measurements of MOPS pain scores at 1, 2, 6, 12, 18, and 24 h after extubation were similar in both groups. The incidence of nonsurgical complications was similar in both groups.

CONCLUSIONS

MTPB is non-inferior to TPVB in attenuating the intraoperative hemodynamic stress response to noxious surgical stimuli and in reducing perioperative opioid consumption, extubation time, and ICU discharge time. Moreover, MTPB is technically easier than TPVB and requires less time to perform. Clinical trial registration number The clinical trial registration was prospectively performed at the Pan African Clinical Trials Registry (PACTR202204901612169, approval date 01/04/2022, URL https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=22602).

Erector spinae plane block reduces opioid consumption and improves incentive spirometry volume after cardiac surgery: A retrospective cohort study

BACKGROUND

Effective postoperative pain management is vital in cardiac surgery to prevent opioid dependency and respiratory complications. Previous studies on the erector spinae plane (ESP) block have focused on single-shot applications or immediate postoperative outcomes. This study evaluates the efficacy of continuous ESP block vs conventional care in reducing opioid consumption and enhancing respiratory function recovery postcardiac surgery over 72 hours.

METHODS

A retrospective study at a tertiary hospital (January 2021-July 2022) included 262 elective cardiac surgery patients. Fifty-three received a preoperative ESP block, matched 1:1 with a control group (n = 53). The ESP group received 0.5% ropivacaine intraoperatively and 0.16% ropivacaine every 4 hours postoperatively. Outcomes measured were cumulative oral morphine equivalent (OME) dose within 72 hours postextubation, daily maximum numerical rating scale (NRS) ≥3, incentive spirometry volume, and %baseline performance, stratified by surgery type (sternotomy or thoracotomy).

RESULTS

Significant OME reduction was observed in the ESP group (sternotomy: median decrease of 113 mg, 95% CI: 60-157.5 mg, p < 0.001; thoracotomy: 172.5 mg, 95% CI: 45-285 mg, p = 0.010). The ESP group also had a lower risk of daily maximum NRS ≥3 (adjusted OR sternotomy: 0.22, p < 0.001; thoracotomy: 0.07, p < 0.001), a higher incentive spirometry volumes (sternotomy: mean increase of 149 mL, p = 0.019; thoracotomy: 521 mL, p = 0.017), and enhanced spirometry %baseline (sternotomy: mean increase of 11.5%, p = 0.014; thoracotomy: 26.5%, p < 0.001).

CONCLUSION

Continuous ESP block was associated with a reduction of postoperative opioid requirements, lower instances of pain scores ≥3, and improve incentive spirometry performance following cardiac surgery. These benefits appear particularly prominent in thoracotomy patients. Further prospective studies with larger sample size are required to validate these findings.

Craniocaudal spread and clinical translation for combined erector spinae plane block and retrolaminar block in soft embalmed cadavers: a randomised controlled equivalence study

BACKGROUND

Erector spinae plane (ESP) block spread can be unpredictable. We previously improved the spread of ESP injection by addition of retrolaminar (RL) injection. However, it is not clear whether spread at high thoracic levels is similar to spread at midthoracic levels. Our primary objective was to demonstrate that craniocaudal dye spread was equivalent after combined ESP and RL injection using a 19 G Tuohy needle at the third (T3) and sixth (T6) vertebrae in soft embalmed Thiel cadavers.

METHODS

We randomised 20 combined ESP and RL injections to the T3 and T6 vertebral levels on both sides of 10 prone Thiel cadavers. A 3-8 MHz transducer was placed in the paramedian sagittal plane and a single anaesthetist injected 10 ml dye onto the transverse process, then 10 ml dye onto the laminae of T3 or T6. Cadavers were dissected 24 h later.

RESULTS

Mean (sd) craniocaudal spread of dye after combined ESP + RL injection at T3 and T6 vertebral levels was equivalent: 8.6 (1.8) vs 8.7 (2.3) levels, respectively; difference (90% confidence interval): -0.1 (-1.4 to 1.6), P=0.904. Dye extended uniformly, cranially and caudally, from the point of injection. A 3D prosection created from a Thiel cadaver confirmed that the dorsal ramus emerges from the costotransverse foramen deep to the intertransverse ligament within the retro-superior costotransverse ligament space. Combined ESP and RL block in six patients before mastectomy achieved extensive anterior, lateral, and posterior chest wall paraesthesia over four to six dermatomes.

CONCLUSIONS

Combined ESP and RL injections showed equivalent and consistent spread at T3 and T6 injection sites. A pilot study confirmed translation to patients.

Comparison of Multiple Injection Costotransverse Block and Erector Spinae Plane Block for Post-Sternotomy Pain Relief in Pediatric Patients Undergoing Cardiac Surgery: A Prospective Randomized Comparative Study

OBJECTIVE

The aim of this study was to evaluate the efficacy of ultrasound-guided multiple injection costotransverse block (MICB) and compare it with erector spinae plane block (ESPB) for poststernotomy pain relief in pediatric cardiac surgical patients.

DESIGN

A prospective, randomized, double-blind, comparative study.

SETTING

At a single institution tertiary referral cardiac center.

PARTICIPANTS

A total of 90 children with acyanotic congenital heart disease requiring surgery via sternotomy.

INTERVENTIONS

Children were allocated randomly to 1 of the 3 following groups: ESPB (group 1), MICB (group 2), or Control (group 3). Participants in groups 1 and 2 received 4 mg/kg of 0.2% ropivacaine for bilateral ultrasound-guided block after induction of anesthesia. Postoperatively, intravenous paracetamol was used for multimodal analgesia, and fentanyl/tramadol was used for rescue analgesia.

MEASUREMENTS AND MAIN RESULTS

The modified objective pain score (MOPS) was evaluated at 0, 1, 2, 4, 6, 8, 10, and 12 hours postextubation. After all exclusions, 84 patients were analyzed. The MOPS score was found to be significantly lower in ESPB and MICB groups compared to the control group until 10 hours postextubation (p < 0.05), with no statistically significant difference at the 12th hour (p = 0.2198). The total intraoperative fentanyl consumption (p = 0.0005), need for fentanyl supplementation on incision (p < 0.0001), and need for rescue opioid requirement in the postoperative period (p = 0.034) were significantly lower in both the ESPB and MICB groups than the control group. There were no statistically significant differences in both primary and secondary outcomes between the ESPB and MICB groups.

CONCLUSION

Ultrasound-guided MICB was effective and comparable to ESPB for post-sternotomy pain management in pediatric cardiac surgical patients.

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.

Empirical guide to a safe thoracic paravertebral block based on dimensions of paravertebral space when ultrasound visualization is challenging

Although ultrasound (US) guidance is the mainstay technique for performing thoracic paravertebral blocks, situations arise when US imaging is limited due to subcutaneous emphysema or extremely deep structures. A detailed understanding of the anatomical structures of the paravertebral space can be strategic to safely and accurately perform a landmark-based or US-assisted approach. As such, we aimed to provide an anatomic roadmap to assist physicians. We examined 50 chest CT scans, measuring the distances of the bony structures and soft-tissue surrounding the thoracic paravertebral block at the 2nd/3rd (upper), 5th/6th (middle), and 9th/10th (lower) thoracic vertebral levels. This review of radiology records controlled for individual differences in body mass index, gender, and thoracic level. Midline to the lateral aspect of the transverse process (TP), the anterior-to-posterior distance of TP to pleura, and rib thickness range widely based on gender and thoracic level. The mean thickness of the TP is 0.9±0.1 cm in women and 1.1±0.2 cm in men. The best target for initial needle insertion from the midline (mean length of TP minus 2 SDs) distance would be 2.5 cm (upper thoracic)/2.2 cm (middle thoracic)/1.8 cm (lower thoracic) for females and 2.7 cm (upper)/2.5 cm (middle)/2.0 cm (lower thoracic) for males, with consideration that the lower thoracic region allows for a lower margin of error in the lateral dimension because of shorter TP. There are different dimensions for the key bony landmarks of a thoracic paravertebral block between males and females, which have not been previously described. These differences warrant adjustment of landmark-based or US-assisted approach to thoracic paravertebral space block for male and female patients.

Differential nerve blockade to explain anterior thoracic analgesia without sensory blockade after an erector spinae plane block may be wishful thinking

Ultrasound-guided erector spinae plane block (ESPB) is currently used as a component of multimodal analgesic regimen in a multitude of indications but the mechanism by which it produces anterior thoracic analgesia remains a subject of controversy. This is primarily the result of ESPB's failure to consistently produce cutaneous sensory blockade (to pinprick and cold sensation) over the anterior hemithorax. Nevertheless, ESPB appears to provide 'clinically meaningful analgesia' in various clinical settings. Lately, it has been proposed that the discrepancy between clinical analgesia and cutaneous sensory blockade could be the result of differential nerve blockade at the level of the dorsal root ganglion. In particular, it is claimed that at a low concentration of local anesthetic, the C nerve fibers would be preferentially blocked than the Aδ nerve fibers. However, the proposal that isolated C fiber mediated analgesia with preserved Aδ fiber mediated cold and pinprick sensation after an ESPB is unlikely, has never been demonstrated and, thus, without sufficient evidence, cannot be attributed to the presumed analgesic effects of an ESPB.

Combined thoracic erector spinae plane and inter-transverse plane blocks for awake breast surgery

Worldwide, breast cancer is the most commonly diagnosed cancer in women. Surgical procedures are typically performed using general anaesthesia, often complemented by regional anaesthesia to manage postoperative pain. However, avoidance of general anaesthesia for breast surgery may be desirable for clinical reasons or patient choice. It is theorised that the use of regional anaesthesia and the avoidance of volatile anaesthetics and opioid analgesia may have beneficial effects on oncological outcomes, and there is some evidence to support this. While many patients successfully undergo awake breast surgery, a limited number of anaesthetists possess direct experience of this approach, despite familiarity with regional anaesthesia techniques. Undertaking regional anaesthesia for awake breast surgery requires patient cooperation and excellent staff teamwork. Here, we present a case of a patient who underwent awake bilateral mastectomy with reconstruction. This was carried out under two 'paravertebral-by-proxy' blocks: the thoracic erector spinae plane and inter-transverse plane blocks, with intravenous sedation.

Thoracic Erector Spinae Plane (T-ESP) Block Together With Intertransverse Process (ITP) Block for Laparoscopic Abdominal Surgery: A Case Report

Laparoscopy has become a milestone with reduced surgical stress and postoperative pain. Evidence promotes erector spinae block for laparoscopic abdominal surgery, in particular for cholecystectomy. The thoracic paravertebral space block is the administration of local anesthetic into a wedge-shaped space on the antero-lateral thoracic spine and provides abdominal analgesia. We hypothesized that a combination of two paravertebral by proxy blocks (erector spinae and intertransverse process (ITP)) with multi-dermatomeric coverage and visceral pain control, with evidence for intra- and postoperative analgesia in thoracic and abdominal surgeries, may be a surgical anesthesia option for laparoscopy. A 42-year-old patient with gastroesophageal reflux disease (GERD) was scheduled for a laparoscopic Nissen fundoplication. He was 173 cm in height and weighed 90 kg (BMI 30 kg.m-2) and was classified in the American Society of Anesthesiologists Physical Status Classification System (ASA-PS) as 2. He had a history of difficult airway and refused general anesthesia. With the patient's informed written consent, we performed a bilateral thoracic erector spinae plane (T-ESP)/ITP blocks at the T4-8 level. Surgery was performed with the patient spontaneously breathing under sedation without complications. Hence, the combination of ESP-ITP blocks was a good anesthesia option for the planned surgery without side effects and optimal postoperative pain control.

Chest Wall and Abdominal Blocks for Thoracic and Abdominal Surgeries: A Review

PURPOSE OF REVIEW

The purpose of this review is to provide an up-to-date description and overview of the rapidly growing literature pertaining to techniques and clinical applications of chest wall and abdominal fascial plane blocks in managing perioperative pain.

RECENT FINDINGS

Clinical evidence suggests that regional anesthesia blocks, including fascial plane blocks, such as pectoralis, serratus, erector spinae, transversus abdominis, and quadratus lumborum blocks, are effective in providing analgesia for various surgical procedures and have more desirable side effect profile when compared to traditional neuraxial techniques. They offer advantages such as reduced opioid consumption, improved pain control, and decreased opioid-related side effects. Further research is needed to establish optimal techniques and indications for these blocks. Presently, they are a vital instrument in a gamut of multimodal analgesia options, especially when there are contraindications to neuraxial or para-neuraxial procedures. Ultimately, clinical judgment and provider skill set determine which blocks-alone or in combination-should be offered to any patient.

Efficacy of bi-level erector spinae plane block versus bi-level thoracic paravertebral block for postoperative analgesia in modified radical mastectomy: a prospective randomized comparative study

BACKGROUND

Postoperative analgesia in breast surgery is difficult due to the extensive nature of the surgery and the complex innervation of the breast; general anesthesia can be associated with regional anesthesia techniques to control intra- and post-postoperative pain. This randomized comparative study aimed to compare the efficacy of the erector spinae plane block and the thoracic paravertebral block in radical mastectomy procedures with or without axillary emptying.

METHODS

This prospective randomized comparative study included 82 adult females who were randomly divided into two groups using a computer-generated random number. Both groups, Thoracic Paraverterbal block group and Erector Spinae Plane Block group (41 patients each), received general anesthesia associated with a multilevel single-shot thoracic paravertebral block and a multilevel single-shot erector spinae plane block, respectively. Postoperative pain intensity (expressed as Numeric Rating Scale), patients who needed rescue analgesic, intra- and post-operative opioid consumption, post-operative nausea and vomiting, length of stay, adverse events, chronic pain at 6 months, and the patient's satisfaction were recorded.

RESULTS

At 2 h (p < 0.001) and 6 h (p = 0.012) the Numeric Rating Scale was significantly lower in Thoracic Paraverterbal block group. The Numeric Rating Scale at 12, 24, and 36 postoperative hours did not show significant differences. There were no significant differences also in the number of patients requiring rescue doses of NSAIDs, in intra- and post-operative opioid consumption, in post-operative nausea and vomiting episodes and in the length of stay. No failures or complications occurred in the execution of techniques and none of the patients reported any chronic pain at six months from the surgery.

CONCLUSIONS

Both thoracic paravertebral block and erector spinae plane block can be effectively used in controlling post-mastectomy pain with no significant differences between the two blocks.

TRIAL REGISTRATION

The study was prospectively registered on Clinicaltrials.gov (trial identifier NCT04457115) (first registration 27/04/2020).

Comparison between costotransverse foramen block and thoracic paravertebral block for VATS pulmonary resection: A randomized noninferiority trial

STUDY OBJECTIVE

The present study assessed whether costotransverse foramen block (CTFB) is noninferior to thoracic paravertebral block (TPVB) for postoperative analgesia in video-assisted thoracoscopic surgery (VATS) pulmonary resection.

DESIGN

Single-center, double-blinded, randomized, non-inferiority trial.

SETTING

Operating room and intensive care unit or ward in a tertiary hospital.

PATIENTS

Patients aged 20 to 80 years with American Society of Anesthesiology physical status 1 to 3 scheduled for elective VATS pulmonary resection.

INTERVENTIONS

Sixty patients were randomly allocated 1:1 to receive CTFB or TPVB using 15 mL aliquots of 0.5% ropivacaine at the T4-5 and T6-7 intercostal levels immediately after the induction of general anesthesia.

MEASUREMENTS

The primary outcome was the area under the curve (AUC) of numeric rating scale (NRS, 0 to 10) during 24 h postoperatively (noninferiority limit was 24; NRS 1 per hour). The secondary outcomes included postoperative opioid consumption, rescue analgesic use, postoperative nausea and vomiting, pulmonary function, dermatomal spread of the blockade, and quality of recovery.

MAIN RESULTS

Forty-seven patients were included for final analysis. The difference between the mean 24-h AUCs of NRS in the CTFB (34.25 ± 16.30, n = 24) and TPVB (39.52 ± 17.13, n = 23) groups was -5.27 (95% confidence interval [CI], -15.09 to 4.55), with the upper limit of 95% CI being far below the predefined noninferiority margin of 24. There was no significant difference in the dermatomal spread of the blockades between the groups, as both reached the upper and lower most levels of T3 and T7 (median). Additionally, there were no significant differences in other secondary outcomes between the two groups.

CONCLUSIONS

The analgesic effect of CTFB was noninferior to that of TPVB during 24 h postoperatively in VATS pulmonary resection. Moreover, CTFB may offer potential safety benefits by keeping the tip of the needle far from the pleura and vascular structure.

Erector spinae plane block: the ultimate 'plan A' block?

The erector spinae plane block (ESPB) is one of seven 'Plan A' blocks proposed by Regional Anaesthesia UK, covering the key areas of commonly encountered surgeries and acute pain. Unlike the other six blocks, the ESPB can be performed at all levels of the spine and provides analgesia to most regions of the body, leading to the argument that the ESPB is the ultimate Plan A block. Current studies show a high level of evidence supporting use in thoracoabdominal surgery but a lack of benefit in upper and lower limb surgery compared with local infiltration and other Plan A blocks. Thus, there is insufficient evidence to support the claim that the erector spinae plane block is the ultimate Plan A block.

Comparison between ultrasound-guided multi-injection intertransverse process and thoracic paravertebral blocks for major breast cancer surgery: a randomized non-inferiority trial

BACKGROUND

This study investigated whether a novel multi-injection intertransverse process block could provide non-inferior analgesia and recovery quality following major breast cancer surgery compared with the multi-injection thoracic paravertebral block.

METHODS

Eighty-eight females who underwent mastectomy plus sentinel or axillary lymph node dissection were randomized to receive either intertransverse process block or thoracic paravertebral block, both performed at T2-6 with 5 mL of 0.5% ropivacaine per level. The primary outcome was the worst resting pain score (11-point Numerical Rating Scale) within 30 min in the recovery room. The secondary outcome was recovery quality (15-item quality of recovery scale) 24 hours after surgery, which was tested following a gatekeeping procedure.

RESULTS

The worst resting pain scores were 0 (0, 1) in the intertransverse process block group vs 0.5 (0, 2) in the thoracic paravertebral block group, with a median difference of 0 (95% CI 0 to 0); the upper 95% CI limit was lower than the prespecified non-inferiority margin of 1 point (non-inferiority p<0.001). Aggregate scores of recovery quality at 24 hours postoperatively were 137.5 (126.5, 142.8) and 137.5 (127.8, 145.0) for the intertransverse process and thoracic paravertebral block groups, respectively, with a median difference of -1 (95% CI -6 to 3); the lower 95% CI limit was larger than the prespecified non-inferiority margin of -8 (non-inferiority p=0.006).

CONCLUSIONS

Compared with a multi-injection thoracic paravertebral block, the multi-injection intertransverse process block provided non-inferior analgesia within 30 min in the recovery room and recovery quality at 24 hours following major breast cancer surgery in females.

TRIAL REGISTRATION NUMBER

ChiCTR2000037963.

Bolus intertransverse process block and continuous erector spinae plane block for perioperative analgesic management of video-assisted thoracoscopic surgery - Three cases report

BACKGROUND

Common regional anesthesia approaches for video-assisted thoracoscopic surgery (VATS) include paravertebral block (PVB) and erector spinae plane block (ESPB). PVB is considered a deep nerve block which is contraindicated in antithrombotic therapy. ESPB is effective when administered as a bolus, as well as continuously. However, the recently proposed intertransverse process block (ITPB) ensures more effective diffusion of the local anesthetic into the paravertebral space.

CASE

We report cases of three patients who received bolus ITPB (costotransverse foramen block and mid-point transverse process-to-pleura block in one and two cases, respectively) combined with continuous ESPB when a deep nerve block could not be administered. Opioids were not required postoperatively, and all postoperative numerical rating scale scores (0-10) at rest were maintained below 4.

CONCLUSIONS

The combination of bolus ITPB and continuous ESPB may be an alternative analgesic method when deep nerve blocks are contraindicated in VATS.

The analgesic efficacy of paravertebral block at T11 level as a single anaesthetic technique in an older adult with severe cardiac insufficiency undergoing open complex inguinal hernia repair: A case report

Background

We describe a case of severe cardiac insufficiency in an older adult undergoing open complex inguinal hernia repair. We present paravertebral injection technique at lower vertebral level without additional needle entry. The feasibility of this technique was verified by observing its intraoperative and postoperative analgesic effects.

Case presentation

A 91-year-old male patient was admitted to the hospital with a very large mass in the right lower abdomen. Diagnostic ultrasonography revealed right inguinal irreducible hernia. The patient had severe cardiac insufficiency with a high risk of general and spinal anaesthesia. After adequate preoperative evaluation and cardiac therapy, the anesthesiologist determined to perform paravertebral block at T11 level using 20 mL of ropivacaine (0.5%) as a single anaesthetic technique to complete the operation. The surgery went uneventfully without using any auxiliary analgesics or sedative drugs. The first reported pain was 19 h after surgery. On the 11-point numeric rating scale, the highest and lowest pain scores within the first 24 h were 3 and 0, respectively. On postoperative day three, the patient was discharged and recovered without complications in 7 days and underwent one-month follow-up.

Conclusions

Single paravertebral block at T11 level with 20 mL of ropivacaine (0.5%) may be an effective intraoperative anaesthetic technique in older adults with severe cardiac decompensation undergoing complex open inguinal hernia repair. The advantage of this technique was that the ipsilateral somatic and sympathetic nerves above and below the injection site could be blocked without additional needle insertion.

Regional Anesthesia for Thoracic and Abdominal Surgery: Tips and Tricks for the Surgeon

The use of ultrasound-guided regional anesthesia (UGRA) has flourished over the past two decades with the description of many novel techniques and the incorporation of UGRA into patient care pathways for many types of surgery, including thoracic and abdominal surgery. Numerous facial plane blocks have been developed for analgesia of the chest and abdomen. Though analgesic efficacy varies based on the specific technique, it is important to be aware of the regional anesthesia techniques in common usage, their analgesic distributions, side effect profiles, and efficacy. In this review, we describe fascial plane blocks developed since 2010 as well as older regional anesthesia techniques and provide context for how and why they might be incorporated into patient care pathways. We will provide salient details on block coverage and briefly discuss evidence and relevant controversies around their use.

Programmed intermittent bolus infusion vs. continuous infusion for erector spinae plane block in video-assisted thoracoscopic surgery: A double-blinded randomised controlled trial

BACKGROUND

The optimal form of administration for erector spinae plane block has not been established.

OBJECTIVE

To compare the efficacy of programmed intermittent bolus infusion (PIB) and continuous infusion for erector spinae plane block.

DESIGN

A prospective, randomised, double-blind study.

SETTING

A single centre between June 2019 and March 2020.

PATIENTS

Included patients had an American Society of Anesthesiologists physical status 1 to 3 and were scheduled for video-assisted thoracic surgery.

INTERVENTIONS

Patients were randomised to receive continuous infusion (0.2% ropivacaine 8 ml h-1; Group C) or PIB (0.2% ropivacaine 8 ml every 2 h; Group P).

MAIN OUTCOME MEASURES

The primary outcome was the number of desensitised dermatomes in the midclavicular line, measured 21 h after first bolus injection.

RESULTS

Fifty patients were randomly assigned to each group; finally, the data of 24 and 25 patients in Group C and P, respectively, were analysed. The mean difference in the number of desensitised dermatomes in the midclavicular line at 5 and 21 h after the initial bolus administration was 1.0 [95% confidence interval (CI) 0.5 to 1.5] and 1.6 (95% CI 1.1 to 2.0), respectively, which was significantly higher in Group P than in Group C (P < 0.001). The median difference in rescue morphine consumption in the early postoperative period (0 to 24 h) was 4 (95% CI 1 to 8) mg, which was significantly lower in Group P (P = 0.035). No significant difference in the postoperative numerical rating scale score was found between the groups.

CONCLUSIONS

PIB for erector spinae plane block in video-assisted thoracic surgery resulted in a larger anaesthetised area and required a lower anaesthetic dose to maintain the analgesic effect. Therefore, it is more suitable for erector spinae plane block than continuous infusion.

TRIAL REGISTRATION

UMIN Clinical Trials Registry (UMIN-CTR, ID: UMIN000036574, Principal investigator: Taro Fujitani, 04/22/2019, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000041671).

Comparison of the Postoperative Analgesic Effects between Ultrasound-Guided Transmuscular Quadratus Lumborum Block and Thoracic Paravertebral Block in Laparoscopic Partial Nephrectomy Patients: A Randomized, Controlled, and Noninferiority Study

Background

This prospective, randomized, double-blinded, noninferiority study aimed to compare the effects of analgesia and recovery between transmuscular quadratus lumborum block (TMQLB) and paravertebral block (PVB).

Methods

Sixty-eight, American Society of Anesthesiologists level I-III patients, who underwent laparoscopic partial nephrectomy in Peking Union Medical College Hospital were randomly allocated to either TMQLB or PVB group (independent variable) in a 1 : 1 ratio. The TMQLB and PVB groups received corresponding regional anesthesia preoperatively with 0.4 ml/kg of 0.5% ropivacaine and follow-up at postoperative 4, 12, 24, and 48 hours. The participants and outcome assessors were blinded to group allocation. We hypothesized that the primary outcome, postoperative 48-hour cumulative morphine consumption, in the TMQLB group was not more than 50% of that in the PVB group. Secondary outcomes including pain numerical rating scales (NRS) and postoperative recovery data were dependent variables.

Results

Thirty patients in each group completed the study. The postoperative 48-hour cumulative morphine consumption was 10.60 ± 5.28 mg in the TMQLB group and 6.40 ± 3.40 mg in the PVB group. The ratio (TMQLB versus PVB) of postoperative 48-hour morphine consumption was 1.29 (95% CI: 1.13-1.48), indicating a noninferior analgesic effect of TMQLB to PVB. The sensory block range was wider in the TMQLB group than in the PVB group (difference 2 dermatomes, 95% CI 1 to 4 dermatomes, P=0.004). The intraoperative analgesic dose was higher in the TMQLB group than in the PVB group (difference 32 µg, 95% CI: 3-62 µg, P=0.03). The postoperative pain NRS at rest and on movement, incidences of side effects, anesthesia-related satisfaction, and quality of recovery scores were similar between the two groups (all P  >  0.05).

Conclusions

The postoperative 48-hour analgesic effect of TMQLB was noninferior to that of PVB in laparoscopic partial nephrectomy. This trial is registered with NCT03975296.

Paravertebral block versus erector spinae plane block for analgesia in modified radical mastectomy: a randomized, prospective, double-blind study

BACKGROUND

Pain control after breast surgery is crucial and supported with regional techniques. Paravertebral block (TPVB) is shown to be effective in postoperative pain management. Erector spinae plane block (ESPB) is assumed to have a similar analgesic effect as an easier and safer block. Our aim was to compare TPVB and ESPB for modified radical mastectomy (MRM) in terms of analgesic efficiency and dermatomal spread.

METHODS

Patients were randomized into Group E (ESPB) and Group P (TPVB). Total 83 patients completed study 42 in Group E and 41 in Group P. Blocks were performed under ultrasonography with 20 mL 0.375% bupivacaine at T4 prior to surgery. T1-10 dermatomal block was examined via pin-prick sensation on the midaxillary and midclavicular lines. Primary outcome was 24-hour morphine consumption. Dermatomal coverage, postoperative 0th minute, 30th minute, 1st, 4th, 6th, 12th and 24th hours pain scores, rescue analgesia requirement and adverse events were secondary outcomes.

RESULTS

Morphine consumption was lower in Group P (19.2±2.9 vs. 21±3.1, P=0.007; mean difference 1.8 mg, 95%CI=0.48-3.1 mg). The number of dermatomes with total loss of sensation was higher in Group P. Pain scores were significantly lower in Group P at all time points. The incidence of complications and adverse events was similar in both groups.

CONCLUSIONS

Thoracal paravertebral block reduced morphine consumption compared to ESPB after MRM, albeit a small difference. A through coverage of TPVB may be preferred with experienced operators in MRM due to lower pain scores.

Hematoma After Continuous Erector Spinae Plane Block With Catheter Placement: A Case Report

The erector spinae plane block (ESPB) is described as a safe and effective alternative when epidural or paravertebral blocks are contraindicated by anticoagulation therapy. We present a case of subcutaneous hematoma after ESPB catheter placement. The patient received bilateral ESPB catheters for perioperative pain control. Postoperatively, the patient developed tenderness to palpation at the left catheter site. Physical examination revealed a well circumscribed, fluctuant mass that produced bloody material during incision and drainage. This case report describes hematoma as a potential complication of the ESPB. After the procedure, patients should be closely monitored for complications, including hematoma.

Retrodural space of Okada in the posterior ligamentous complex region: clinical and anatomical findings relevant to lumbar interlaminar epidural injection

Background

The retrodural space of Okada is a potential space posterior to the ligamentum flavum that allows communication with the bilateral facet joints. However, the actual anatomy of this space has not been clearly visualized to date. We sought to investigate the characteristics of patients showing contrast spreading to the facet joint space during epidural injection and to clarify the anatomical structures of the retrodural space and adjacent ligamentous tissues in cadaveric specimens.

Methods

Fluoroscopic images of patients who underwent fluoroscopy-guided lumbar interlaminar epidural injection were assessed for contrast flow to the facet joints. Patient demographics, preprocedural imaging study findings, and epidural approaches were analyzed. The anatomical study included the sectional dissection, micro-CT imaging, and histological evaluation of lumbar spine specimens from 16 embalmed cadavers.

Results

Fluoroscopic images of 605 epidural injections were analyzed. Among them, 36 with inadvertent spread into the facet joints (5.9%) were identified. Multivariate analysis revealed that facet joint pathologies were significantly associated with inadvertent spread into the facet joints (OR 4.382; 95% CI 1.160 to 16.558; p=0.029). Micro-CT and histological findings consistently showed a retrodural space between the ligamentum flavum and interspinous ligament. Various anatomical communication routes in the posterior ligamentous complex leading to this space were observed in specimens with degenerative and pathological changes.

Conclusion

Degenerative and pathological facet joint changes were associated with a higher incidence of spread into the retrodural space during epidural injection. Our findings confirm anatomical evidence for a false loss of resistance before the needle enters the epidural space.

Erector spinae block: beyond the torso

PURPOSE OF REVIEW

This article aims to summarize the current literature describing the application of erector spinae plane (ESP) blocks for regional anesthesia of upper and lower limbs and to discuss the advantages and limitations.

RECENT FINDINGS

Investigations are still at an early stage but results are promising. High thoracic ESP blockade can relieve acute and chronic shoulder pain through local anesthetic diffusion to cervical nerve roots, although it may not be as effective as direct local anesthetic injection around the brachial plexus. It does, however, preserve motor and phrenic nerve function to a greater extent. It will also block the T2 innervation of the axilla which can be a source of pain in complex arthroscopic shoulder surgery. Lumbar ESP blocks provide effective analgesia following hip arthroplasty and arthroscopy, and appear comparable to lumbar plexus, quadratus lumborum, and fascia iliaca blocks. Unlike the latter, they are motor-sparing and are associated with improved postoperative ambulation.

SUMMARY

High thoracic and lumbar ESP blocks have the potential to provide adequate analgesia of the upper and lower limbs respectively, without causing significant motor block. They are thus alternative methods of regional anesthesia when other techniques are not feasible or have undesirable adverse effects.

Anatomical classification and clinical application of thoracic paraspinal blocks

Various techniques for regional anesthesia and analgesia of the thorax are currently being used in clinical practice. A recent international consensus has anatomically classified paraspinal blocks in the thoracic spinal region into the following four types: paravertebral, retrolaminar, erector spinae plane, and intertransverse process blocks. These blocks have different anatomical targets; thus, the spreading patterns of the injectates differ and can consequently exhibit different neural blockade characteristics. The paravertebral block directly targets the paravertebral space just outside the neuraxial region and has an analgesic efficacy comparable to that of the epidural block; however, there are multiple potential risks associated with this technique. Retrolaminar and erector spinae plane blocks target the erector spinae plane on the vertebral lamina and transverse process, respectively. In anatomical studies, these two blocks showed different injectate spreading patterns to the back muscles and the fascial plane. In cadaveric studies, paravertebral spread was identified, but variable. However, numerous clinical reports have shown paravertebral spread with erector spinae plane blocks. Both techniques have been found to reduce postoperative pain compared to controls; however, the results have been more inconsistent than with the paravertebral block. Finally, the intertransverse process block targets the tissue complex posterior to the superior costotransverse ligament. Anatomical studies have revealed that this block has pathways that are more direct and closer to the paravertebral space than the retrolaminar and erector spinae plane blocks. Cadaveric evaluations have consistently shown promising results; however, further clinical studies using this technique are needed to confirm these anatomical findings.

Ultrasound-Guided Extraforaminal Thoracic Nerve Root Block Through the Midpoint of the Inferior Articular Process and the Parietal Pleura: A Clinical Application of Thoracic Paravertebral Nerve Block

Purpose

Thoracic nerve root (TNR) block is performed primarily under computed tomography or X-ray fluoroscopy but is associated with radiation exposure. Ultrasound requires no radiation and distinguishes vessels, nerves, pleura, and other tissues. Few reports of ultrasound-guided TNR (US-TNR) block have been described, and the puncture end point has not been clearly defined. Herein, we evaluated the feasibility of US-TNR block using the midpoint of the inferior articular process (IAP) and parietal pleura (PP) as the puncture end point.

Patients and Methods

A prospective series of 10 patients with Herpes Zoster-associated pain underwent US-TNR-guided block performed using an in-plane technique with the midpoint of thoracic IAP and PP as the puncture end points of ultrasonography. The US-TNR block procedure was performed with ultrasound as the primary imaging tool followed by fluoroscopic confirmation.

Results

In all patients, the needle tips were visible at the lateral margin of the pedicle in the anteroposterior view and at the extraforaminal zone in the lateral view. The TNR and dorsal root ganglion (DRG) were delineated in all 10 patients. Furthermore, 2 mL of radiopaque agent could delineate the epidural space in 8 patients and the thoracic paravertebral (TPV) space in the other 2 patients. All patients developed numbness along the corresponding dermatome 30 min after injection of local anesthetics. The numeric rating scale (NRS) score at baseline, and at two- and four-week follow-ups were 6.50 ± 1.35, 3.50 ± 0.85 (vs NRS at baseline, P < 0.01), and 4.00 ± 0.82 (vs NRS at baseline, P < 0.01), respectively.

Conclusion

This study demonstrated the feasibility of US-TNR block using the in-plane technique with the midpoint of thoracic IAP and PP as the puncture end point to effectively block the TNR and DRG. This technique is an accurate clinical application of TPV nerve block and provides a potential therapeutic option for the treatment of neuropathic pain.

The pathway of injectate spread during thoracic intertransverse process (ITP) block: Micro-computed tomography findings and anatomical evaluations

STUDY OBJECTIVE

To investigate the mechanism of action of the thoracic intertransverse process (ITP) block.

DESIGN

Three-dimensional micro-computed tomography (3D micro-CT) study and cadaveric evaluation.

SETTING

A translational research unit for anatomy and analgesia in a university hospital.

PATIENTS

Twelve embalmed and three non-embalmed human cadavers were used in this study.

MEASUREMENTS

Micro-CT images of the mid-thoracic paravertebral space and its adjacent ligamentous tissues were acquired and 3D images were reconstructed. Manual dissection and histologic examination of these structures complemented the images. To confirm our findings, the dye-spreading pattern after ultrasound-guided ITP injection of 20 mL dye solution at T4-T5 was evaluated.

MAIN RESULTS

Micro-CT and histologic findings showed that the costotransverse foramen (the medial slit of the superior costotransverse ligament) and the costotransverse space (between the rib and the transverse process) were potential pathways to the thoracic paravertebral space during ITP block. Single-level ITP injection with a dye solution resulted in a multilevel segmental paravertebral spread in cadaveric evaluation.

CONCLUSIONS

The space posterior to the superior costotransverse ligament, the target area for ITP blocks, has potential anatomical pathways to the thoracic paravertebral space. The costotransverse foramen and the costotransverse space provided the anatomical conduit for the anterior and intersegmental paravertebral spread of the ITP block.