Comparison of Paravertebral Block by Anatomic Landmark Technique to Ultrasound-Guided Paravertebral Block for Breast Surgery Anesthesia: A Randomized Controlled Trial

Use of corticosteroids for adult chronic pain interventions: sympathetic and peripheral nerve blocks, trigger point injections - guidelines from the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, the American Society of Interventional Pain Physicians, the International Pain and Spine Intervention Society, and the North American Spine Society

BACKGROUND

There is potential for adverse events from corticosteroid injections, including increase in blood glucose, decrease in bone mineral density and suppression of the hypothalamic-pituitary axis. Published studies note that doses lower than those commonly injected provide similar benefit.

METHODS

Development of the practice guideline was approved by the Board of Directors of American Society of Regional Anesthesia and Pain Medicine with several other societies agreeing to participate. The scope of guidelines was agreed on to include safety of the injection technique (landmark-guided, ultrasound or radiology-aided injections); effect of the addition of the corticosteroid on the efficacy of the injectate (local anesthetic or saline); and adverse events related to the injection. Based on preliminary discussions, it was decided to structure the topics into three separate guidelines as follows: (1) sympathetic, peripheral nerve blocks and trigger point injections; (2) joints; and (3) neuraxial, facet, sacroiliac joints and related topics (vaccine and anticoagulants). Experts were assigned topics to perform a comprehensive review of the literature and to draft statements and recommendations, which were refined and voted for consensus (≥75% agreement) using a modified Delphi process. The United States Preventive Services Task Force grading of evidence and strength of recommendation was followed.

RESULTS

This guideline deals with the use and safety of corticosteroid injections for sympathetic, peripheral nerve blocks and trigger point injections for adult chronic pain conditions. All the statements and recommendations were approved by all participants after four rounds of discussion. The Practice Guidelines Committees and Board of Directors of the participating societies also approved all the statements and recommendations. The safety of some procedures, including stellate blocks, lower extremity peripheral nerve blocks and some sites of trigger point injections, is improved by imaging guidance. The addition of non-particulate corticosteroid to the local anesthetic is beneficial in cluster headaches but not in other types of headaches. Corticosteroid may provide additional benefit in transverse abdominal plane blocks and ilioinguinal/iliohypogastric nerve blocks in postherniorrhaphy pain but there is no evidence for pudendal nerve blocks. There is minimal benefit for the use of corticosteroids in trigger point injections.

CONCLUSIONS

In this practice guideline, we provided recommendations on the use of corticosteroids in sympathetic blocks, peripheral nerve blocks, and trigger point injections to assist clinicians in making informed decisions.

Safety and Complications of Landmark-based Paravertebral Blocks: A Retrospective Analysis of 979 Patients and 4983 Injections

OBJECTIVE

This study aimed to determine the incidence of complications after landmark-based paravertebral blocks for breast surgery.

METHODS

The medical records of patients who received a paravertebral block for breast surgery between 2019 and 2022 were reviewed. Patient age, sex, type of procedure, number of injections, volume of injected anesthetic, and possible complications were noted. A record was identified as a possible serious block-related complication if there was concern or treatment for local anesthetic systemic toxicity, pneumothorax, altered mental status, or intrathecal/epidural spread. Other complications recorded were immediate postblock hypotension and nausea/vomiting requiring treatment and unanticipated postsurgical admission. Patients receiving ultrasound-guided paravertebral blocks were excluded from this study.

RESULTS

Over a 3-year period, 979 patients received paravertebral blocks using the landmark technique for breast surgery, totaling 4983 injections. Overall, 6 patients required assessment for postblock issues (0.61%), including hypotension (2 patients), nausea (3 patients), and hypotension + altered mental status (1 patient). This latter patient was identified as having a serious complication related to the paravertebral block (0.1%). This patient had unintentional intrathecal spread and altered mental status that required mechanical ventilation. The incidence of block-related hypotension and nausea requiring treatment was thus 0.31% and 0.31% respectively. Four patients required unanticipated admission, but none were for block-related reasons. No patients in this study were found to have local anesthetic systemic toxicity or pneumothorax.

CONCLUSION

Our study suggests that landmark-based paravertebral blocks for breast surgery result in a very low complication rate and are a safe technique for postsurgical analgesia.

Local anesthetic dosing and toxicity of adult truncal catheters: a narrative review of published practice

BACKGROUND/IMPORTANCE

Anesthesiologists frequently use truncal catheters for postoperative pain control but with limited characterization of dosing and toxicity.

OBJECTIVE

We reviewed the published literature to characterize local anesthetic dosing and toxicity of paravertebral and transversus abdominis plane catheters in adults.

EVIDENCE REVIEW

We searched the literature for bupivacaine or ropivacaine infusions in the paravertebral or transversus abdominis space in humans dosed for 24 hours. We evaluated bolus dosing, infusion dosing and cumulative 24-hour dosing in adults. We also identified cases of local anesthetic systemic toxicity and toxic blood levels.

FINDINGS

Following screening, we extracted data from 121 and 108 papers for ropivacaine and bupivacaine respectively with a total of 6802 patients. For ropivacaine and bupivacaine, respectively, bolus dose was 1.4 mg/kg (95% CI 0.4 to 3.0, n=2978) and 1.0 mg/kg (95% CI 0.18 to 2.1, n=2724); infusion dose was 0.26 mg/kg/hour (95% CI 0.06 to 0.63, n=3579) and 0.2 mg/kg/hour (95% CI 0.06 to 0.5, n=3199); 24-hour dose was 7.75 mg/kg (95% CI 2.1 to 15.7, n=3579) and 6.0 mg/kg (95% CI 2.1 to 13.6, n=3223). Twenty-four hour doses exceeded the package insert recommended upper limit in 28% (range: 17%-40% based on maximum and minimum patient weights) of ropivacaine infusions and 51% (range: 45%-71%) of bupivacaine infusions. Toxicity occurred in 30 patients and was associated with high 24-hour dose, bilateral catheters, cardiac surgery, cytochrome P-450 inhibitors and hypoalbuminemia.

CONCLUSION

Practitioners frequently administer ropivacaine and bupivacaine above the package insert limits, at doses associated with toxicity. Patient safety would benefit from more specific recommendations to limit excessive dose and risk of toxicity.

Analgesic efficacy of erector spinae plane block versus paravertebral block in lung surgeries-A non-inferiority randomised controlled trial

BACKGROUND

Pain management plays an essential role in postoperative recovery after lung surgeries. The Erector Spinae Plane Block (ESPB) is a widely used regional anaesthesia technique; however, few clinical trials have compared this block to active control in thoracic surgeries. This study evaluated the non-inferiority of the analgesia provided by ESPB when compared to paravertebral block (PVB) in lung surgeries.

METHODS

Randomised, active-controlled, blinded for patients and assessors, non-inferiority trial. Patients who underwent unilateral lung surgeries were divided into two groups according to the regional anaesthesia technique-continuous ESPB or PVB at the T5 level. The primary outcome was to assess pain using a numerical rating scale (NRS) with a test of the interaction of three measures over 24 h postoperatively. An NRS score ≥ 7 was considered analgesia failure, and the prespecified non-inferiority margin was 10%.

RESULTS

In the interim analysis that terminated this study, 120 participants were enrolled. ESPB patients reported higher mean NRS general values over 24 h, 4.6 ± 3.2 in the ESPB group versus 3.9 ± 2.9 in the PVB group, with a difference of -0.67 (-15.2%) and 95%CI: -1.29 to -0.05 (p = .02), demonstrating not non-inferiority. In addition, the ESPB group presented higher NRS failure of analgesia over 24 h (p < .01) and required more postoperative opioids (p = .01 over 24 h). There was no difference in patient satisfaction between groups.

CONCLUSION

This trial demonstrated that a continuous erector spinae plane block was not non-inferior to a continuous paravertebral block for analgesia after lung surgery but resulted in higher levels of postoperative pain and opioid consumption.

Regional Analgesia for Cesarean Delivery: A Narrative Review Toward Enhancing Outcomes in Parturients

Introduction

With the current surge on peripheral nerve blocks in post-cesarean pain management and the historical lack of unequivocal evidence supporting its universal use, this review intended to re-examine the extended scope of literature on regional anesthesia and postoperative analgesia in low-transverse cesarean section.

Methods

A literature search was conducted up to April 2023 using PubMed to identify articles relevant to our search words "cesarean section", "neuraxial morphine", "post-cesarean analgesia", as well as the name of each individual nerve block. The literature search was ultimately narrowed to systematic reviews and randomized controlled trials published between 2012 and 2023. We define, describe, and discuss the evidence surrounding each individual regional anesthetic technique in the presence and absence of intrathecal morphine, which is used as the gold standard when appropriate.

Results

In the absence of neuraxial morphine, all regional anesthetic techniques have some level of analgesic benefit in the post-cesarean analgesia. Transversus Abdominis Plane blocks continue to have the most studies in their use. Newer fascia plane blocks including the anterior Quadratus Lumborum, and Erector Spinae Plane blocks provide significant analgesia. In addition, direct comparison among peripheral nerve blocks consistently favors the more proximal, centralized techniques. Conversely, in the presence of neuraxial morphine, no peripheral anesthetic technique has reliably and reproducibly demonstrated an added analgesic benefit regardless of the peripheral nerve block technique or location of local anesthetic injection in the post-cesarean population.

Conclusion

Neuraxial morphine continues to be the gold standard for post-cesarean section analgesia, the benefit of additional single injection regional anesthetic is currently not evidence supported. In cases where neuraxial opioids have not or cannot be given, there is overwhelming evidence that regional anesthetic techniques improve post-cesarean section analgesia and decrease post-operative opioid consumption. Even though there is no consensus on the optimal peripheral nerve block, emerging evidence suggests more centralized abdominal fascia plane block trends towards better analgesia.

Comparative Study Between Conventional Landmark Versus Ultrasound-Guided Paravertebral Block in Patients Undergoing Laparoscopic Cholecystectomy: A Randomized Controlled Study

INTRODUCTION

Thoracic paravertebral block (TPVB) has emerged as an effective and safe regional technique for providing postoperative analgesia. We aimed to compare the ease and efficacy of conventional landmark and ultrasound-guided (USG) paravertebral blocks for postoperative analgesia in patients undergoing laparoscopic cholecystectomy.

METHODS

This was a randomized controlled study. Seventy-six patients of either sex, age 18-40 years, body mass index (BMI) 18-29 kg/m², American Society of Anesthesiologists physical status classifications I and II posted for elective laparoscopic cholecystectomy under general anesthesia were randomly allocated into two groups of 38 each. Patients in group A were administered a paravertebral block using the anatomical landmark technique (ALT), and group B using an ultrasound-guided paravertebral block in the sitting position. In both groups, 20 ml of 0.5% bupivacaine injection was administered at the T7 vertebral level on the right side. The primary outcome was the first-pass success rate. Secondary outcomes were the number of passes and attempts, duration of analgesia, visual analog scale (VAS) score for pain during 24 h postoperatively and complications if any, were recorded.

RESULTS

No patients were excluded in the study. Demographic characteristics were comparable in both groups. The number of passes was less in group B (1.45±0.5) compared to group A (2.42±0.95) and was reported to be statistically significant (p = 0.001). The number of attempts was less in group B (1.00±0) as compared to group A (1.29±0.46) and was statistically significant (p = 0.001). The duration of analgesia was longer in group B (530.00±326.33 minutes) compared to group A (345.60±252.95 minutes) and was observed to be statistically significant (p<0.05). The VAS score was significantly lower in group B (1.87±0.78, 2.24 ±0.82) compared to group A (2.42±0.72, 3.13±1.07) at the second and fourth hours, respectively (p = 0.001).  Conclusion: We concluded that paravertebral block using an ultrasound-guided technique is more efficacious than the conventional landmark technique for postoperative analgesia in patients undergoing laparoscopic cholecystectomy.

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.

Combined Programmed Intermittent Bolus Infusion With Continuous Infusion for the Thoracic Paravertebral Block in Patients Undergoing Thoracoscopic Surgery: A Prospective, Randomized, and Double-blinded Study

BACKGROUND

Continuous thoracic paravertebral block (TPVB) connected with patient-controlled analgesia (PCA) pump is an effective modality to reduce postoperative pain following thoracic surgery. For the PCA settings, the programmed intermittent bolus infusion (PIBI) and continuous infusion (CI) are commonly practiced. However, the comparative effectiveness between the 2 approaches has been inconsistent. Thus, the aim of this study was to explore the optimal PCA settings to treat postthoracotomy pain by combing PIBI and CI together.

METHODS

All enrolled patients undergoing thoracoscopic surgery accepted ultrasound-guided TPVB catheterization before the surgery and then were randomly allocated in to 3 groups depending on different settings of the PCA pump connecting to the TPVB catheter: the PIBI+CI, PIBI, and CI groups. Numerical Rating Scales were evaluated for each patient at T1 (1 h after extubation), T2 (12 h after the surgery), T3 (24 h after the surgery), T4 (36 h after the surgery), and T5 (48 h after the surgery). Besides, the consumptions of PCA ropivacaine, the number of blocked dermatomes at T3, and the requirement for extra dezocine for pain relief among the 3 groups were also compared.

RESULTS

First, the Numerical Rating Scale scores in the PIBI+CI group were lower than the CI group at T2 and T3 (P<0.05) when patients were at rest and were also lower than the CI group at T2, T3, and T4 (P<0.01) and the PIBI group at T3 when patients were coughing (P<0.01). Second, the 2-day cumulative dosage of PCA in the PIBI+CI group was lower than both the CI and PIBI groups (P<0.01). Third, the number of blocked dermatomes in the PIBI and PIBI+CI groups were comparable and were both wider than the CI group at T3 (P<0.01). Finally, a smaller proportion (not statistically significant) of patients in the PIBI+CI group (5.26%, 2/38) had required dezocine for pain relief when compared with the PIBI group (19.44%, 7/36) and the CI group (15.79%, 6/38).

CONCLUSIONS

The combination of PIBI and CI provides superior analgesic modality to either PIBI or CI alone in patients undergoing thoracoscopic surgery. Therefore, it should be advocated to improve the management of postoperative pain, clinical outcomes, and ultimately patient satisfaction.

Chest Wall Nerve Blocks for Cardiothoracic, Breast Surgery, and Rib-Related Pain

PURPOSE OF REVIEW

Perioperative analgesia in patients undergoing chest wall procedures such as cardiothoracic and breast surgeries or analgesia for rib fracture trauma can be challenging due to several factors: the procedures are more invasive, the chest wall innervation is complex, and the patient population may have multiple comorbidities increasing their susceptibility to the well-defined pain and opioid-related side effects. These procedures also carry a higher risk of persistent pain after surgery and chronic opioid use making the analgesia goals even more important.

RECENT FINDINGS

With advances in ultrasonography and clinical research, regional anesthesia techniques have been improving and newer ones with more applications have emerged over the last decade. Currently in cardiothoracic procedures, para-neuraxial and chest wall blocks have been utilized with success to supplement or substitute systemic analgesia, traditionally relying on opioids or thoracic epidural analgesia. In breast surgeries, paravertebral blocks, serratus anterior plane blocks, and pectoral nerve blocks have been shown to be effective in providing pain control, while minimizing opioid use and related side effects. Rib fracture regional analgesia options have also expanded and continue to improve.  Advances in regional anesthesia have tremendously improved multimodal analgesia and contributed to enhanced recovery after surgery protocols. This review provides the latest summary on the use and efficacy of chest wall blocks in cardiothoracic and breast surgery, as well as rib fracture-related pain and persistent postsurgical pain.

Ultrasound-Guided Nerve Blocks for Painful Hand Injuries: A Randomized Control Trial

Objectives: Traumatic hand injuries present to emergency departments frequently. Pain secondary to these injuries is typically managed with opioids, which may be inadequate and have side effects. Ultrasound (US)-guided forearm nerve blocks have emerged as an alternative modality for patients with acute pain from isolated extremity injuries.

Methods: We performed a non-blinded, consecutive, randomized pragmatic trial of US-guided forearm nerve blocks using medium and long-acting anesthetic versus usual care for a six-day period around July 4th, 2017. Adults who sustained a traumatic or blast injury of their hands were considered. Consecutive emergency department patients were consented, enrolled and randomized into a study group (block) or control (standard care). The study group received a US-guided forearm block using a 50/50 mix of 1% lidocaine and 0.5% bupivacaine. The primary outcome was median pain scores via a 100-point visual analog scale at 15, 60, and 120 minutes after the nerve block compared to the baseline pain score. The secondary outcome was mean morphine equivalents administered.

Results: Sixteen patients were screened and 12 were randomized: six to the treatment group and six to the control group. Median pain reduction from baseline at 15, 60, and 120 minutes in the forearm block group was -35 (IQR=10), -30 (IQR=50), and -20 (IQR=70, versus -5 (IQR=10), -20.5 (IQR=20), -20 (IQR=70) in the control group. At all time points, patient-reported pain scores decreased significantly over baseline in the forearm block group, whereas non-significant reductions in pain scores occurred in the control group.

Conclusion: US-guided forearm blocks for acute traumatic hand injuries resulted in greater pain relief when compared to usual care.

Safety of treatment options available for postoperative pain

IntroductionPostoperative pain is one of the most common adverse events after surgery and has been shown to increase the risk of other complications. On the other hand, liberal opioid use in the perioperative period is also associated with risk of adverse events. The current consensus is therefore to provide multimodal, opioid minimizing analgesia after surgery.Areas CoveredIn this review, we will discuss the benefits and risks associated with non-opioid analgesics, including non-steroidal anti-inflammatory drugs, gabapentinoids, ketamine, α-2 agonists, and corticosteroids. In addition, we will discuss the general and block-specific risks associated with regional anesthestic techniques.Expert OpinionAdverse events associated with non-opioid analgesics are rare outside their specific contraindicated patient groups, especially when dosed appropriately. α-2 agonists can cause transient hypotension and bradycardia, and gabapentinoids may cause sedation in higher risk patient populations. Regional anesthesia techniques are generally safe when done by an experienced practitioner. We therefore encourage the development of standardized multimodal analgesic protocols, which may facilitate opioid minimization and lead to better patient outcomes.

European Society of Anaesthesiology and Intensive Care Guidelines on peri-operative use of ultrasound for regional anaesthesia (PERSEUS regional anesthesia): Peripheral nerves blocks and neuraxial anaesthesia

Nowadays, ultrasound-guidance is commonly used in regional anaesthesia (USGRA) and to locate the spinal anatomy in neuraxial analgesia. The aim of this second guideline on the PERi-operative uSE of UltraSound (PERSEUS-RA) is to provide evidence as to which areas of regional anaesthesia the use of ultrasound guidance should be considered a gold standard or beneficial to the patient. The PERSEUS Taskforce members were asked to define relevant outcomes and rank the relative importance of outcomes following the GRADE process. Whenever the literature was not able to provide enough evidence, we decided to use the RAND method with a modified Delphi process. Whenever compared with alternative techniques, the use of USGRA is considered well tolerated and effective for some nerve blocks but there are certain areas, such as truncal blocks, where a lack of robust data precludes useful comparison. The new frontiers for further research are represented by the application of USG during epidural analgesia or spinal anaesthesia as, in these cases, the evidence for the value of the use of ultrasound is limited to the preprocedure identification of the anatomy, providing the operator with a better idea of the depth and angle of the epidural or spinal space. USGRA can be considered an essential part of the curriculum of the anaesthesiologist with a defined training and certification path. Our recommendations will require considerable changes to some training programmes, and it will be necessary for these to be phased in before compliance becomes mandatory.

Ultrasound versus thoracoscopic-guided paravertebral block during thoracotomy

BACKGROUND

Paravertebral block can be performed with the aid of surgical landmarks, ultrasound, or a thoracoscope. This study was designed to compare ultrasound-guided paravertebral block with the thoracoscopic technique.

METHODS

This prospective randomized comparative study included 40 adults scheduled for elective thoracic surgery. Study participants were randomized to an ultrasound group or a thoracoscope group. A catheter for paravertebral block was inserted prior to thoracotomy with real-time ultrasound visualization in the ultrasound group, and under thoracoscopic guidance in the thoracoscope group. Total analgesic consumption, visual analogue pain score, technical difficulties, and complications were compared between the 2 groups.

RESULTS

Total analgesic consumption in the first 24 hours was less in the ultrasound group than in the thoracoscope group (rescue intravenous fentanyl 121.25 ± 64.01 µg in the ultrasound group vs. 178.75 ± 91.36 µg in the thoracoscope group; p = 0.027). Total paravertebral bupivacaine consumption was 376.00 ± 33.779 mg in the ultrasound group and 471.50 ± 64.341 mg in the thoracoscope group (p < 0.001). Technical difficulties and complications in terms of time consumed during the maneuver, more than one needle pass, and pleural puncture were significantly lower in the ultrasound group than in the thoracoscope group.

CONCLUSION

Ultrasound-guided paravertebral catheter insertion is more effective, technically easier, and safer than the thoracoscope-assisted technique.

Distribution of injectate administered through a catheter inserted by three different approaches to ultrasound-guided thoracic paravertebral block: a prospective observational study

Background

Despite the popularity of continuous thoracic paravertebral block (TPVB), there is a paucity of information on catheter tip position and distribution of injectate through the catheter. We observed, in real time, the spread of dye, the catheter tip position and sensory block levels produced with three different (intercostal (IC), transverse process sagittal (TS) and paralaminar (PL)) approaches to ultrasound-guided TPVB in patients undergoing video-assisted thoracoscopic surgery.

Methods

After the induction of general anesthesia, ultrasound-guided TPVB was conducted with a patient in the lateral decubitus position. During surgery, 10 mL of dye was injected through a catheter to observe the catheter tip and the dye distribution under thoracoscopy. Dermatomal sensory block levels were measured postoperatively.

Results

Ten patients for each of three different approaches completed the study. There were a variety of dye spreading patterns. The median (range) number of segmental levels stained with dye was 1.5 (1–4), 3 (1–4) and 3 (1–5) with the IC, TS and PL approaches, respectively. We observed that a catheter tip was present at the same segmental paravertebral space as intended in 50%–90% of patients using these approaches. The median (range) number of dermatomes with sensory blockade at 6 hours after block was 2.5 (1–4), 3 (2–8) and 3 (1–8) with the IC, TS and PL approaches, respectively.

Conclusions

Although a bolus injection through a catheter for ultrasound-guided TPVB produced multiple levels of spread and sensory blockade in more than half the patients, considerable differences existed in the spread regardless of approach.

Paravertebral block: anatomy and relevant safety issues

Paravertebral block, especially thoracic paravertebral block, is an effective regional anesthetic technique that can provide significant analgesia for numerous surgical procedures, including breast surgery, pulmonary surgery, and herniorrhaphy. The technique, although straightforward, is not devoid of potential adverse effects. Proper anatomic knowledge and adequate technique may help decrease the risk of these effects. In this brief discourse, we discuss the anatomy and technical aspects of paravertebral blocks and emphasize the importance of appropriate needle manipulation in order to minimize the risk of complications. We propose that, when using a landmark-based approach, limiting medial and lateral needle orientation and implementing caudal (rather than cephalad) needle redirection may provide an extra margin of safety when performing this technique. Likewise, recognizing a target that is not in close proximity to the neurovascular bundle when using ultrasound guidance may be beneficial.

Programmed intermittent bolus infusion versus continuous infusion of 0.2% levobupivacaine after ultrasound-guided thoracic paravertebral block for video-assisted thoracoscopic surgery: A randomised controlled trial

BACKGROUND

The analgesic benefits of programmed intermittent bolus infusion for thoracic paravertebral block remain unknown.

OBJECTIVE

The aim of this study was to compare the analgesia from intermittent bolus infusion with that of a continuous infusion after thoracic paravertebral block.

DESIGN

A randomised controlled study.

SETTING

A single centre between December 2016 and November 2017. Seventy patients scheduled for video-assisted thoracoscopic surgery were included in the study.

INTERVENTION(S)

Patients were randomly assigned to receive 0.2% levobupivacaine via continuous infusion (5 ml h, continuous group) or programmed intermittent bolus infusion (15 ml every 3 h, bolus group) after an initial 15-ml bolus injection of 0.2% levobupivacaine.

MAIN OUTCOME MEASURES

The main outcome was the amount of rescue fentanyl (per kg of body weight) consumed within 24 h after surgery. Secondary outcomes were postoperative pain scores, plasma levobupivacaine concentrations and the number of dermatomes anaesthetised.

RESULTS

There was no significant difference between the continuous and bolus groups in the postoperative consumption of fentanyl (median [interquartile range] 5.5 [4 to 9.5] μg kg versus 6 [3.5 to 9] μg kg respectively, P = 0.45) and postoperative pain scores within 24 h. At 20 h after initiating the infusions, there was no statistically significant difference between the two groups in terms of the plasma levobupivacaine concentration. The number of dermatomes anaesthetised to pinprick and cold testing was significantly greater in the bolus group.

CONCLUSION

Our findings suggest that postoperative pain and opioid usage are similar with either programmed intermittent bolus infusion or continuous infusion after thoracic paravertebral block. Programmed intermittent bolus infusion provides a wider sensory blockade and could benefit patients requiring a wider extent of anaesthesia.

TRIAL REGISTRATION

UMIN Clinical Trials Registry (UMIN-CTR; URL: http://umin.ac.jp/ctr/, ID: UMIN000023378).

Are single-injection erector spinae plane block and multiple-injection costotransverse block equivalent to thoracic paravertebral block?

BACKGROUND

Thoracic paravertebral block (TPVB) is considered the gold standard for hemithoracic regional anaesthesia. Erector spinae plane block (ESPB) is a new posterior thoracic wall block. Multiple-injection costotransverse block (MICB) mimics TPVB but with injection points within the thoracic intertransverse tissue complex and posterior to the superior costotransverse ligament. We aimed to compare the spread of injectate into the thoracic paravertebral space (TPVS) resulting from single-injection ESPB and MICB, respectively, with TPVB.

METHODS

Ten soft-embalmed cadavers were utilised. In five cadavers, the right hemithorax was randomly allocated either to ultrasound-guided single-injection ESPB or single-injection TPVB; vice versa on the other side. In another five cadavers, the right hemithorax was randomly allocated either to ultrasound-guided MICB or multiple-injection TPVB. About 20 mL of dye was injected in each hemithorax with all techniques.

RESULTS

With TPVB, the dye was consistently present in the TPVS with concomitant epidural spread in the majority of cases. The injectate spread into the TPVS with ESPB (60%) and MICB (100%). MICB consistently stained the ventral rami (T1-7), communicating rami and thoracic sympathetic trunk without epidural spread. Dissection after MICB revealed dye spread into the TPVS via the costotransverse foramina and along the dorsal branches of the posterior intercostal veins.

CONCLUSIONS

Consistent spread of dye into the TPVS colouring the ventral rami, the communicating rami, and the sympathetic trunk was observed with MICB; in this respect equivalent to TPVB. ESPB exhibited only partial success and was not equivalent to TPVB. No epidural spread was found with neither MICB nor ESPB.

Thoracic paravertebral block: comparison of different approaches and techniques. A study on 27 human cadavers

BACKGROUND AND OBJECTIVES

The success rate and spread of thoracic paravertebral block (TPVB) are variable and difficult to predict. It is now recommended that an ultrasound guidance technique should replace the traditional landmark technique. The objective was to compare anatomical outcomes of both techniques on cadavers.

METHODS

A landmark technique (loss of resistance technique [LOR]) and a USG technique (three approaches: sagittal, transversal in-plane, transverse out-of-plane) were performed on 27 thawed non-embalmed cadavers. Each of the four approaches was performed in each body (T3-T5 and T9-T11 × right and left). A coloured solution (13 mL, saline 0.9%) was injected in the targeted thoracic paravertebral space (TPVS). A successful thoracic paravertebral injection (TPVI) was defined by the presence of dye in at least one TPVS during anatomical dissection.

RESULTS

In 104 TPVIs analysed, the overall success rate was 78%. Factors associated with success were: USG versus LOR technique (85% vs. 52%, P < 0.0007), sagittal versus both transversal approaches (93%/81%/83%, P < 0.0007) and right side (86% vs. 66%). The median spread was 2 TPVS (min - max 1-5) with a median cephalad-caudal spread of 5 cm (min - max 1-18). By multivariate analysis, the sagittal approach was an independent factor of success (OR 2.75). Dye spread and pleural entry were influenced by neither the approach nor the site of injection.

CONCLUSIONS

Paravertebral spread of TPVI is variable. USG technique has higher anatomical success rates than the LOR technique, the sagittal USG approach being the most successful.