Pleural Puncture and Intrathoracic Catheter Placement During Ultrasound Guided Paravertebral Block

Anatomical assessments of injectate spread stratified by the volume of the intertransverse process block at the T2 level

BACKGROUND

This cadaveric study aimed to analyze injectate spread to target nerves during a single-injection, ultrasound-guided intertransverse process block.

METHODS

An ultrasound-guided intertransverse process block with three different injectate volumes was administered to 12 cadavers. Each hemithorax was subjected to computer-generated random allocation of 10, 15, or 20 mL ultrasound-guided, single-injection intertransverse process block at the T2 vertebral level. Latex dye solution was injected into each hemithorax in accordance with the allocated volume. The presence of dye at the nerve root in the sympathetic chain and intercostal nerves at various injection levels was examined via dissection.

RESULTS

Injectate spread into the dorsal rami was observed in seven of eight (87.5%), seven of eight (87.5%), and all eight (100%) of the 10, 15, and 20 mL specimens, respectively. In all 20 mL specimens, consistent staining of the dorsal rami, spinal nerve, and dorsal root ganglion was observed.

CONCLUSIONS

An injectate volume of 20 mL was required for consistent staining of the dorsal rami, spinal nerve, and dorsal root ganglion in an intertransverse process block. Although an augmented injectate volume was associated with an increased likelihood of target nerve staining, consistent staining of the sympathetic ganglion, rami communicans, and ventral ramus was not observed, even at a volume of 20 mL. The current study presents initial findings suggesting that as opposed to a sympathetic ganglion block, a 20 mL intertransverse process block may act as a feasible substitute for dorsal root ganglion, spinal nerve, and medial branch blocks within a clinical context.

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).

Comparison of injectate spread and nerve coverage between single-injection intertransverse process block and paravertebral block at the T2 level: a cadaveric study

BACKGROUND

We compared the spread of an injectate into the thoracic sympathetic chain resulting from a single-injection intertransverse process (ITP) block with that of a single-injection PV block at the T2 level.

METHODS

Sixteen soft-embalmed cadavers were used. The right hemithorax was randomly allocated to receive either an ultrasound-guided single-injection ITP block or ultrasound-guided single-injection PV block at the T2 vertebral level, with the opposite block administered to the other side. Approximately 10 mL of latex dye solution was injected into each hemithorax using a random allocation technique. The presence of dye at the nerve root in the sympathetic chain and intercostal nerves at the injection and additional levels was examined by dissection.

RESULTS

The injectate spread into the T2 sympathetic ganglion on both ITP (11/16, 68.8%) and PV (16/16, 100%) blocks. The ITP block demonstrated greater uniformity of dye staining in both the dorsal rami and dorsal root ganglion, which contrasts with the less consistent staining outcomes of the PV block in these regions.

CONCLUSIONS

At the T2 level, we observed a lower efficacy of the ITP block for analgesic coverage of the sympathetic nerve. This suggested a potential preference by clinicians for the application of the T2 PV block over the ITP block, specifically for the management of sympathetically maintained pain in the upper extremities. In addition, our findings may hint at the potential advantages of the ITP block in specific clinical contexts where targeted nerve involvement, such as the medial branch block or dorsal root ganglion block, is sought.

Regional anesthesia for breast cancer surgery: which block is best? A review of the current literature

Breast cancer is the most common type of cancer worldwide. Fortunately, continual advances in diagnosis and treatment are resulting in increased survival rates. Earlier detection and treatment, to include surgical resection, can greatly improve patients outcomes. However, due to the complex innervation of the breast, management of postoperative pain has proven difficult in the past. Approximately, half of all women who undergo breast cancer surgery report postoperative pain syndrome. The paravertebral block has long been the anesthesiologist's choice for mitigating pain during and after the procedure. Newer techniques such as the pectoral nerve block and erector spinae plane block may prove to have some additional benefits. This literature review compares the risks, benefits and specific uses of these three regional nerve blocks in women undergoing breast cancer surgery. It aims to better inform anesthesiologists when they are choosing which technique is best for their patients.

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.

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

BACKGROUND

A precise anatomical understanding of the thoracic paravertebral space (TPVS) is essential to understanding how an injection outside this space can result in paravertebral spread. Therefore, we aimed to clarify the three-dimensional (3D) structures of the TPVS and adjacent tissues using micro-CT, and investigate the potential routes for nerve blockade in this area.

METHODS

Eleven embalmed cadavers were used in this study. Micro-CT images of the TPVS were acquired after phosphotungstic acid preparation at the mid-thoracic region. The TPVS was examined meticulously based on its 3D topography.

RESULTS

Micro-CT images clearly showed the serial topography of the TPVS and its adjacent spaces. First, the TPVS was a very narrow space with the posterior intercostal vessels very close to the pleura. Second, the superior costotransverse ligament (SCTL) incompletely formed the posterior wall of the TPVS between the internal intercostal membrane and vertebral body. Third, the retro-SCTL space broadly communicated with the TPVS via slits, costotransverse space, intervertebral foramen, and erector spinae compartment. Fourth, the costotransverse space was intersegmentally connected to the adjacent retro-SCTL space.

CONCLUSIONS

A non-destructive, multi-sectional approach using 3D micro-CT more comprehensively demonstrated the real topography of the intricate TPVS than previous cadaver studies. The posterior boundary and connectivity of the TPVS provides an anatomical rationale for the notion that paravertebral spread can be achieved with an injection outside this space.

Comparison of local and regional anesthesia modalities in breast surgery: A systematic review and network meta-analysis

STUDY OBJECTIVE

Moderate to severe postoperative pain occurs in up to 60% of women following breast operations. Our aim was to perform a network meta-analysis and systematic review to compare the efficacy and side effects of different analgesic strategies in breast surgery.

DESIGN

Systematic review and network meta-analysis.

SETTING

Operating room, postoperative recovery room and ward.

PATIENTS

Patients scheduled for breast surgery under general anesthesia.

INTERVENTIONS

Following an extensive search of electronic databases, those who received any of the following interventions, control, local anesthetic (LA) infiltration, erector spinae plane (ESP) block, pectoralis nerve (PECS) block, paravertebral block (PVB) or serratus plane block (SPB), were included. Exclusion criteria were met if the regional anesthesia modality was not ultrasound-guided. Network plots were constructed and network league tables were produced.

MEASUREMENTS

Co-primary outcomes were the pain at rest at 0-2 h and 8-12 h. Secondary outcomes were those related to analgesia, side effects and functional status.

MAIN RESULTS

In all, 66 trials met our inclusion criteria. No differences were demonstrated between control and LA infiltration in regard to the co-primary outcomes, pain at rest at 0-2 and 8-12 h. The quality of evidence was moderate in view of the serious imprecision. With respect to pain at rest at 8-12 h, ESP block, PECS block and PVB were found to be superior to control or LA infiltration. No differences were revealed between control and LA infiltration for outcomes related to analgesia and side effects, and few differences were shown between the various regional anesthesia techniques.

CONCLUSIONS

In breast surgery, regional anesthesia modalities were preferable from an analgesic perspective to control or LA infiltration, with a clinically significant decrease in pain score and cumulative opioid consumption, and limited differences were present between regional anesthetic techniques themselves.

The analgesic efficacy of a single injection of ultrasound-guided retrolaminar paravertebral block for breast surgery: a prospective, randomized, double-blinded study

Background

The thoracic paravertebral block is an effective analgesic technique for postoperative pain management after breast surgery. The ultrasound-guided retrolaminar block (RLB) is a safer alternative to conventional paravertebral block. Thus, we assessed the analgesic efficacy of ultrasound-guided RLB for postoperative pain management after breast surgery.

Methods

Patients requiring breast surgery were randomly allocated to group C (retrolaminar injection with saline) and group R (RLB with local anesthetic mixture). The RLB was performed at the level of T3 with local anesthetic mixture (0.75% ropivacaine 20 mL + 2% lidocaine 10 mL) under general anesthesia before the skin incision. The primary outcome was cumulative morphine consumption using intravenous patient-controlled analgesia (IV-PCA) at 24 hour postoperatively. The secondary outcomes were the visual analogue scale (VAS) scores at 1, 6, 24, and 48 hour postoperatively and the occurrence of adverse events and patient satisfaction after the surgery.

Results

Forty-six patients were included, 24 in group C and 22 in group R. The cumulative morphine consumption using IV-PCA did not differ between the two groups (P = 0.631). The intraoperative use of remifentanil was higher in group C than in group R (P = 0.025). The resting and coughing VAS scores at 1 hour postoperatively were higher in group R than in group C (P = 0.011, P = 0.004). The incidence of adverse events and patient satisfaction was not significantly different between the two groups.

Conclusions

A single injection of ultrasound-guided RLB did not reduce postoperative analgesic requirements following breast surgery.

Postoperative pain treatment with erector spinae plane block and pectoralis nerve blocks in patients undergoing mitral/tricuspid valve repair - a randomized controlled trial

BACKGROUND

Effective postoperative pain control remains a challenge for patients undergoing cardiac surgery. Novel regional blocks may improve pain management for such patients and can shorten their length of stay in the hospital. To compare postoperative pain intensity in patients undergoing cardiac surgery with either erector spinae plane (ESP) block or combined ESP and pectoralis nerve (PECS) blocks.

METHODS

This was a prospective, randomized, controlled, double-blinded study done in a tertiary hospital. Thirty patients undergoing mitral/tricuspid valve repair via mini-thoracotomy were included. Patients were randomly allocated to one of two groups: ESP or PECS + ESP group (1:1 randomization). Patients in both groups received a single-shot, ultrasound-guided ESP block. Participants in PECS + ESP group received additional PECS blocks. Each patient had to be extubated within 2 h from the end of the surgery. Pain was treated via a patient-controlled analgesia (PCA) pump. The primary outcome was the total oxycodone consumption via PCA during the first postoperative day. The secondary outcomes included pain intensity measured on the visual analog scale (VAS), patient satisfaction, Prince Henry Hospital Pain Score (PHHPS), and spirometry.

RESULTS

Patients in the PECS + ESP group used significantly less oxycodone than those in the ESP group: median 12 [interquartile range (IQR): 6-16] mg vs. 20 [IQR: 18-29] mg (p = 0.0004). Moreover, pain intensity was significantly lower in the PECS + ESP group at each of the five measurements during the first postoperative day. Patients in the PECS + ESP group were more satisfied with pain management. No difference was noticed between both groups in PHHPS and spirometry.

CONCLUSIONS

The addition of PECS blocks to ESP reduced consumption of oxycodone via PCA, reduced pain intensity on the VAS, and increased patient satisfaction with pain management in patients undergoing mitral/tricuspid valve repair via mini-thoracotomy.

TRIAL REGISTRATION

The study was registered on the 19th July 2018 (first posted) on the ClinicalTrials.gov identifier: NCT03592485.

Erector spinae versus paravertebral plane blocks in modified radical mastectomy: Randomised comparative study of the technique success rate among novice anaesthesiologists

Background and Aims:

Regional analgesia may play a role in pain management during breast surgery. Ultrasound approach to paravertebral block may be challenging. This study compared success rates of ultrasound-guided erector spinae plane block (ESPB) versus parasagittal in-plane thoracic paravertebral block among senior anaesthesia residents in modified radical mastectomy.

Methods:

One hundred and two female patients undergoing modified radical mastectomy were randomly categorized into PARA group receiving sagittal in-plane paravertebral block and ESPB group receiving erector spinae plane block. The block in the 1^st six cases in each group was done by an experienced consultant as a demonstration for three anaesthesia residents not experienced in either block. Primary endpoint was assessing success rate of the blocks. Secondary endpoint was the haemodynamic response to skin incision and postoperative analgesia.

Results:

All patients were females undergoing modified radical mastectomy. Success rate among residents was 100% in ESPB versus 77.8% in PARA group (P = 0.002). Duration to perform the block was less in ESPB group (4.39 ± 1.2 min) than PARA group (8.18 ± 2.42 min) (P < 0.0001). Guidance frequency by consultants was significantly higher in PARA than ESPB group. Time to 1^st analgesic requirement and morphine consumption postoperatively were insignificant between the groups. There was no significant difference regarding haemodynamics.

Conclusion:

ESPB may be a simple and safe alternative to parasagittal in-plane paravertebral block to provide postoperative analgesia in modified radical mastectomy especially in novice practitioners. It provides equivalent profile of postoperative analgesia with less time to perform the block.

Influence of injectate volume on paravertebral spread in erector spinae plane block: An endoscopic and anatomical evaluation

The paravertebral spread that occurs after erector spinae plane block may be volume-dependent. This cadaveric study was undertaken to compare the extent of paravertebral spread with erector spinae plane block using different dye volumes. After randomization, twelve erector spinae plane blocks were performed bilaterally with either 10 ml or 30 ml of dye at the level of T5 in seven unembalmed cadavers except for two cases of unexpected pleural puncture using the 10 ml injection. Direct visualization of the paravertebral space by endoscopy was performed immediately after the injections. The back regions were also dissected, and dye spread and nerve involvement were investigated. A total of five 10 ml injections and seven 30 ml injections were completed for both endoscopic and anatomical evaluations. No paravertebral spread was observed by endoscopy after any of the 10-ml injections. Dye spread to spinal nerves at the intervertebral foramen was identified by endoscopy at adjacent levels of T5 (median: three levels) in all 30 ml injections. In contrast, the cases with two, four, and three out of five were stained at only the T4, T5, and T6 levels, respectively, with the 10 ml injection. Upon anatomical dissection, all blocks were consistently associated with posterior and lateral spread to back muscles and fascial layers, especially with the 30 ml injections, which showed greater dye expansion. In one 30 ml injection, sympathetic nerve involvement and epidural spread were observed at the level of the injection site. Although paravertebral spread following erector spinae plane block increased in a volume-dependent manner, this increase was variable and not pronounced. As the injectate volume increased for the erector spinae blocks, the injectate spread to the back muscles and fascial layers seemed to be predominantly increased compared with, the extent of paravertebral spread.

Comparison of injectate spread and nerve involvement between retrolaminar and erector spinae plane blocks in the thoracic region: a cadaveric study

Although different injection locations for retrolaminar and erector spinae plane blocks have been described, the two procedures have a similar anatomical basis. In this cadaveric study we compared anatomical spread of dye in the thoracic region following these two procedures. Following randomisation, 10 retrolaminar blocks and 10 erector spinae plane blocks were performed on the left or right sides of 10 unembalmed cadavers. For each block, 20 ml of dye solution was injected at the T5 level. The back regions were dissected and the involvement of the thoracic spinal nerve was also investigated. Twenty blocks were successfully completed. A consistent vertical spread, with deep staining between the posterior surface of the vertebral laminae and the overlaying transversospinalis muscle was observed in all retrolaminar blocks. Moreover, most retrolaminar blocks were predominantly associated with fascial spreading in the intrinsic back muscles. With an erector spinae plane block, dye spread in a more lateral pattern than with retrolaminar block, and fascial spreading in the back muscles was also observed. The number of stained thoracic spinal nerves was greater with erector spinae plane blocks than with retrolaminar blocks; median 2.0 and 3.5, respectively. Regardless of technique, the main route of dye spread was through the superior costotransverse ligament to the ipsilateral paravertebral space. Although erector spinae plane blocks were associated with a slightly larger number of stained thoracic spinal nerves than retrolaminar blocks, both techniques were consistently associated with posterior spread of dye and with limited spread to the paravertebral space.

Introduction of a novel ultrasound-guided extrathoracic sub-paraspinal block for control of perioperative pain in Nuss procedure patients

BACKGROUND

A safe and effective method of multilevel thoracic pain control remains an elusive goal in patients undergoing the Nuss procedure. The aim of our study was to develop a nonopioid centered approach using a novel regional technique as part of a quality improvement initiative.

METHODS

The proposed ultrasound-guided technique positions multi-perforated soaker catheter deep to the paraspinal muscles from T2 to T11. The project was conducted in two phases. First, a cadaveric dissection was performed to establish the pathway of spread of local anesthetic in vivo. Second, a pilot double blind randomized control project was conducted to evaluate effectiveness of the technique in ten patients and to derive parameters necessary for the definitive future study. Outcomes were evaluated based on the narcotic requirement, pain scores and functional measures.

RESULTS

Placement of the catheters in two cadavers demonstrated reliable positioning in the subparaspinal tissue plane, and multilevel dye spread along the intercostal nerve path. In addition, a potential route of spread toward the paravertebral space along the canal accommodating dorsal ramus of the thoracic nerve was demonstrated. The pilot trial demonstrated a trend in decreased cumulative hydromorphone requirement in comparison to the control group at both 24h (0.19±0.09mg/kg vs. 0.13±0.08mg/kg p=0.72) and 48h (0.37±0.2mg/kg vs. 0.3±0.12mg/kg p=0.37). Functional performance ability was higher in the treatment group on both POD#1 (6.7±1.8 vs. 4.8±1 p=0.0495) and POD#2 (8.9±0.8 vs. 6.5±1.2 p=0.04). Pain scores were similar among the two groups (p=0.96).

CONCLUSIONS

We describe a new technique to treat multilevel thoracic pain following the Nuss procedure that is reproducible, safe, allows diminished opioid use and enhances functional recovery.

Comparison Between Intraoperative Two-Space Injection Thoracic Paravertebral Block and Wound Infiltration as a Component of Multimodal Analgesia for Postoperative Pain Management After Video-Assisted Thoracoscopic Lobectomy: A Randomized Controlled Trial

OBJECTIVE

To compare paravertebral block under thoracoscopy with wound infiltration at an early stage after video-assisted thoracic lobectomy surgery.

DESIGN

A prospective, randomized, triple-blinded, placebo-controlled trial.

SETTING

A single-center university hospital.

PARTICIPANTS

Patients scheduled for video-assisted thoracic lobectomy surgery between February 20, 2014 and June 1, 2014 randomly were allocated into paravertebral block (PVB) (n = 35) and infiltration (n = 35) groups.

INTERVENTIONS

In the PVB group, 0.5% ropivacaine was injected into the paravertebral space by the surgeon under direct vision with placebo infiltration of saline in the wounds. In the infiltration group, the wounds were infiltrated with 0.5% ropivacaine by the surgeon with a placebo paravertebral block. Subsequently, patient-controlled intravenous morphine analgesia and paracoxib were administered.

MEASUREMENTS AND MAIN RESULTS

The primary endpoints were visual analog scale (VAS) pain scores at rest and on cough 0, 2, 6, and 24 hours after surgery. The secondary endpoints were the total morphine during postoperative 0 hours to 24 hours, adverse events, and patient satisfaction with the analgesia. Sixty-one patients completed the study. VAS score on cough at each time point was significantly lower (p<0.05) and median (25th, 75th) morphine consumption was lower in the PVB group than in the infiltration group (26 [10, 35] mg and 42 [29, 58] mg, p<0.001, respectively). There was no difference in VAS score at rest. Patients in the PVB group had higher satisfaction with analgesia than in the infiltration group (p = 0.003).

CONCLUSIONS

As part of the multimodal postoperative analgesia, intraoperative paravertebral block provided better dynamic pain relief and reduced morphine consumption compared with local wound infiltration.