Anatomical basis of fascial plane blocks

Pharmacokinetics in regional anesthesia

PURPOSE OF REVIEW

Pharmacokinetics of local anesthetics are one of the main determinants of success and safety of regional anesthesia and comprise local and systemic distribution phases. This review aims to summarize the latest research findings on this topic in the context of various regional blocks performed for different surgeries and patient populations.

RECENT FINDINGS

Research into local kinetics and systemic absorption of local anesthetics has chiefly been focused on novel fascial plane blocks, especially the erector spinae plane block, as these are increasingly adopted for regional anesthesia and pain management. As their clinical efficacy is very dependent on injection of large volumes of local anesthetic, doses over typically recommended limits are often administered.

SUMMARY

Fascial plane blocks are the regional anesthesia techniques in need of the most pharmacokinetic characterization, not only to better understand their complex mechanisms of action but also to avoid harm from excessive doses of local anesthetics. Further mapping of risk factors for systemic toxicity from administration in different block sites is crucial. Extremes of age and pregnancy are vulnerable patient populations but in whom regional anesthesia, including novel techniques, has been performed with few complications.

Fascial plane blocks: from microanatomy to clinical applications

PURPOSE OF REVIEW

In the last 20 years, advancements in the understanding of fasciae have significantly transformed anaesthesia and surgery. Fascial plane blocks (FPBs) have gained popularity due to their validated safety profile and relative ease. They are used in various clinical settings for surgical and nonsurgical indications. Growing evidence suggests a link between the microscopic anatomy of fasciae and their mechanism of action. As a result, knowledge of these aspects is urgently needed to better optimise pain management. The purpose of this review is to summarise the different microscopic aspects of deep/muscular fascia to expand our understanding in the performance of FPBs.

RECENT FINDINGS

There is ample evidence to support the role of FPBs in pain management. However, the exact mechanism of action remains unclear. Fasciae are composed of various structural elements and display complex anatomical characteristics at the microscopic level. They include various cell types embedded within an extracellular matrix abundant in collagens and hyaluronan. Increasingly, numerous studies demonstrated their innervation that contributes to their sensory functions and their role in proprioception, motor coordination and pain perception. Lastly, the diversity of the cellular and extracellular matrix, with their viscoelastic properties, is essential to understanding the FPBs' mechanism of action.

SUMMARY

Physicians must be aware of the role of fascial microscopic anatomy and better understand their properties to perform FPBs in a conscious manner and enhance pain management.

Analgesic effects of ultrasound-guided preoperative posterior Quadratus Lumborum block in laparoscopic hepatectomy: A prospective double-blinded randomized controlled trial

STUDY OBJECTIVE

To determine if single-injection bilateral posterior quadratus lumborum block (QLB) with ropivacaine would improve postoperative analgesia in the first 24 h after laparoscopic hepatectomy, compared with 0.9% saline.

DESIGN

Prospective, double blinded, randomized controlled trial.

SETTING

A single tertiary care center from November 2021 and January 2023.

PATIENTS

A total of 94 patients scheduled to undergo laparoscopic hepatectomy due to hepatocellular carcinoma.

INTERVENTIONS

Ninety-four patients were randomized into a QLB group (receiving 20 mL of 0.375% ropivacaine on each side, 150 mg in total) or a control group (receiving 20 mL of 0.9% saline on each side).

MEASUREMENTS

The primary outcome was the cumulative opioid consumption during the initial 24-h post-surgery. Secondary outcomes included pain scores and intraoperative and recovery parameters.

MAIN RESULTS

The mean cumulative opioid consumption during the initial 24-h post-surgery was 30.8 ± 22.4 mg in the QLB group (n = 46) and 34.0 ± 19.4 mg in the control group (n = 46, mean differences: -3.3 mg, 95% confidence interval, -11.9 to 5.4, p = 0.457). The mean resting pain score at 1 h post-surgery was significantly lower in the QLB group than in the control group (5 [4-6.25] vs. 7 [4.75-8], p = 0.035). No significant intergroup differences were observed in the resting or coughing pain scores at other time points or in other secondary outcomes.

CONCLUSIONS

Preoperative bilateral posterior QLB did not reduce cumulative opioid consumption during the first 24 h after laparoscopic hepatectomy.

Efficacy of erector spinae plane block for postoperative analgesia after liver surgeries: a systematic review and meta-analysis

BACKGROUND

Data on the effectiveness of erector spinae plane block (ESPB) for patients undergoing liver surgeries is limited and inconclusive. We hereby aimed to systematically review if ESPB can provide adequate analgesia after liver surgery.

METHODS

PubMed, CENTRAL, Scopus, Embase, and gray literature were examined up to 25th April 2023 for randomized controlled trials (RCTs) comparing ESPB with control or spinal analgesia.

RESULTS

Nine RCTs were included of which three compared ESPB with spinal analgesia. 24-hour opioid consumption did not differ significantly between ESPB vs. control (MD: -35.25 95% CI: -77.01, 6.52 I2 = 99%) or ESPB vs. spinal analgesia (MD: 2.32 95% CI: -6.12, 10.77 I2 = 91%). Comparing pain scores between ESPB and control, a small but significant effect favoring ESPB was noted at 12 h and 48 h, but not at 6-8 h and 24 h. Pain scores did not differ between ESPB and spinal analgesia. The risk of postoperative nausea and vomiting was also not significantly different between ESPB vs. control or spinal analgesia. GRADE assessment shows moderate certainty of evidence.

CONCLUSION

ESPB may not provide any significant postoperative analgesia in liver surgery patients. There was a tendency of reduced opioid consumption with ESPB. Limited data also showed that ESPB and spinal analgesia had no difference in pain scores and 24-hour analgesic consumption.

Updates From the Other Side of the Drape: Recent Advances in Multimodal Pain Management and Opioid Reduction Among Pediatric Surgical Patients

As the management of acute pain for children undergoing surgical procedures as well as recognition of the short and long term risks of exposure to opioids has evolved, multimodal and multidisciplinary approaches using organized pathways has resulted in improved perioperative outcomes and patient satisfaction. In this 2023 symposium held at the American Academy of Pediatrics on Surgery meeting, a multidisciplinary discussion on current enhanced recovery after surgery pathways, alternate methods of effective pain control and education and advocacy efforts for opioid reduction were discussed, and highlights are included in this article.

Description and Evaluation of Dye and Contrast Media Distribution of Ultrasound-Guided Rectus Sheath Block in Cat Cadavers

The rectus sheath block is an ultrasound-guided anaesthetic technique which aims to provide analgesia to the abdominal midline. This study aimed to assess the distribution of 0.4 mL kg-1 of a mixture of methylene blue and iopromide injected into each hemiabdomen in the internal rectus sheath in cat cadavers. We hypothesise that this technique would be feasible and would cover the rami ventrales of the last thoracic and the first lumbar spinal nerves. The study was divided into two phases. Phase 1 aimed to study the anatomical structures of the ventral abdominal wall (four cats were dissected). Phase 2 (ten cadavers) consisted of an ultrasound-guided injection of the mixture mentioned above and the assessment of its distribution by computed tomography and anatomical dissection. The results showed the staining of the cranioventral abdominal wall with a craniocaudal spread of four (three to eight) vertebral bodies. Methylene blue stained three (one to four) rami ventrales, affecting T10 (60%), T11 (100%), T12 (90%), T13 (50%) and L1 (5%). Based on these results, it could be stated that this technique could supply anaesthesia to the midline of the abdominal midline cranial to the umbilicus in clinical patients, but it may not be able to provide anaesthesia to the middle and caudal midline abdominal region.

Serum Levels of Bupivacaine After Bilateral Ultrasound-Guided Deep Parasternal Intercostal Plane Block in Cardiac Surgery with Median Sternotomy

OBJECTIVE

To evaluate systemic levels of bupivacaine after bilateral ultrasound-guided deep parasternal intercostal plan (PIP) block in cardiac surgical patients undergoing median sternotomy.

DESIGN

Prospective, observational study SETTING: Single institution; academic university hospital PARTICIPANTS: Twenty-eight adult patients undergoing cardiac surgery with median sternotomy received a PIP block with 2.5 mg/kg bupivacaine with or without dexamethasone and dexmedetomidine.

MEASUREMENTS

Arterial blood samples were analyzed for total serum bupivacaine concentration at 5, 15, 30, 45, 60, 90, 120, and 150 minutes after placement of PIP. Local anesthetic volume, local anesthetic adjuncts, time to extubation, postoperative pain scores, and opioid consumption were recorded.

MAIN RESULTS

The mean peak bupivacaine concentration was 0.60 ± 0.62 µg/mL, and the mean time to maximum concentration (Tmax) was 16.92 ± 12.97 minutes. Two patients (7.1%) had a concentration >2.0 µg/mL within 15 minutes of block placement. The mean Tmax of bupivacaine was significantly greater in patients who did not receive additives compared to those patients who did (22.86 ± 14.77 minutes v 10.0 ± 5.22 minutes; p = .004). The times to extubation and postoperative pain were not improved with additives.

CONCLUSIONS

Bilateral PIP placed at the end of cardiac surgery resulted in low systemic bupivacaine levels. The inclusion of additives shortened Tmax without improving outcome.

A progress of research on the application of fascial plane blocks in surgeries and their future direction: a review article

Fascial plane blocks (FPBs) are gaining popularity in clinical settings owing to their improved analgesia when combined with either traditional regional anesthesia or general anesthesia during the perioperative phase. The scope of study on FPBs has substantially increased over the past 20 years, yet the exact mechanism, issues linked to the approaches, and direction of future research on FPBs are still up for debate. Given that it can be performed at all levels of the spine and provides analgesia to most areas of the body, the erector spinae plane block, one of the FPBs, has been extensively studied for chronic rational pain, visceral pain, abdominal surgical analgesia, imaging, and anatomical mechanisms. This has led to the contention that the erector spinae plane block is the ultimate Plan A block. Yet even though the future of FPBs is promising, the unstable effect, the probability of local anesthetic poisoning, and the lack of consensus on the definition and assessment of the FPB's success are still the major concerns. In order to precisely administer FPBs to patients who require analgesia in this condition, an algorithm that uses artificial intelligence is required. This algorithm will assist healthcare professionals in practicing precision medicine.

Postsurgical Analgesic Effectiveness of Ultrasound-Guided Parasternal Block After Auricular Reconstruction Using Autologous Costal Cartilage in Pediatric Patients: A Randomized Controlled Trial

OBJECTIVE

To study the efficacy of ultrasound-guided parasternal block (US-PSI) in pediatric patients undergoing auricular reconstruction surgery.

METHODS

For this study, the authors recruited 60 children between the ages of 5 and 12 years who underwent auricular reconstruction with autologous costal cartilage (ACC) to correct microtia. They were randomized to receive either ultrasound-guided modified parasternal block or periprostatic local infiltration anesthesia (PLIA), with 30 cases in each group. Ultrasound-guided parasternal block was administered following anesthesia induction, whereas PLIA was administered after ACC harvest. Lastly, following surgery, all children were provided with patient-controlled intravenous analgesia with sufentanil, and the numeric pain rating scale (NRS) was used to assess the intensity of pain. Our primary outcomes were the resting NRS pain scores and the NRS scores upon coughing at 1, 6, 12, 24, and 48 hours postsurgery. Sufentanil consumption within the first 24 hours of surgery, the mean duration to first ambulation, and the usage of rescue analgesics were our secondary outcomes. The authors also recorded the occurrence of undesirable side effects as well as more serious side effects like pneumothorax.

RESULTS

Pediatric patients who were administered US-PSI showed significantly reduced NRS chest pain scores at 6 and 12 hours postsurgery compared to those who received PLIA (P<0.05). In addition, sufentanil consumption within the first 24 hours postsurgery, duration to first ambulation, and use of rescue analgesics were significantly lower among patients in the US-PSI group when compared to those in the PLIA group (P<0.05).

CONCLUSIONS

This study found that US-PSI was a highly efficacious and safe technique for postsurgical analgesia following auricular reconstruction with ACC in pediatric patients.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Optimal techniques of ultrasound-guided superficial and deep parasternal intercostal plane blocks: a cadaveric study

INTRODUCTION

The optimal techniques of a parasternal intercostal plane (PIP) block to cover the T2-T6 intercostal nerves have not been elucidated. This pilot cadaveric study aims to determine the optimal injection techniques that achieve a consistent dye spread over the second to sixth intercostal spaces after both ultrasound-guided superficial and deep PIP blocks. We also investigated the presence of the transversus thoracis muscle at the first to sixth intercostal spaces and its sonographic identification agreement, as well as the location of the internal thoracic artery in relation to the lateral border of the sternum.

METHODS

Ultrasound-guided superficial or deep PIP blocks with single, double, or triple injections were applied in 24 hemithoraces (three hemithoraces per technique). A total volume of dye for all techniques was 20 mL. On dissection, dye distribution over the first to sixth intercostal spaces, the presence of the transversus thoracis muscle at each intercostal space and the distance of the internal thoracic artery from the lateral sternal border were recorded.

RESULTS

The transversus thoracis muscles were consistently found at the second to sixth intercostal spaces, and the agreement between sonographic identification and the presence of the transversus thoracis muscles was >80% at the second to fifth intercostal spaces. The internal thoracic artery is located medial to the halfway between the sternal border and costochondral junction along the second to sixth intercostal spaces. Dye spread following the superficial PIP block was more localized than the deep PIP block. For both approaches, the more numbers of injections rendered a wider dye distribution. The numbers of stained intercostal spaces after superficial block at the second, fourth, and fifth intercostal spaces, and deep block at the third and fifth intercostal spaces were 5.3±1.2 and 5.7±0.6 levels, respectively.

CONCLUSION

Triple injections at the second, fourth, and fifth intercostal spaces for the superficial approach and double injections at the third and fifth intercostal spaces for the deep approach were optimal techniques of the PIP blocks.

Usefulness of ultrasound-guided serratus-anterior block in prevention of postoperative pain after breast surgery. A cohort study

OBJECTIVE

To evaluate superficial serratus anterior plane block's efficacy and side effects in preventing postoperative pain after breast cancer surgery.

METHODOLOGY

A prospective cohort study was conducted on 195 adult patients undergoing breast oncological surgery under general anesthesia (Group G, n = 96) or combined general anesthesia with superficial serratus anterior plane block (Group L, n = 99). Validated preoperative data, which are predictors of chronic postoperative pain of patients, were recorded (type of surgery, age, pain in the area of the intervention and the other regions; anesthetic-surgical data, analgesic doses used, duration of surgery; pain intensity (EVN scale) at immediate postoperative period, 24 h, seven days and one month after the surgery, and complications.

RESULTS

Pain intensity, measured by the EVN scale, had a mean of 1.02 +/- 1.656 in the Postoperative Unit; 1.20 +/- 1.448 at 24 h; 0.76 +/- 1208 seven days; and 0.34 +/- 0.757 one month after surgery. Patients were operated under general anesthesia (n = 96) or general anesthesia combined with the interfascial block (n = 99). Significant differences (p < 0.05) were found in age, height, and VAS scale in PACU. Ten complications were recorded, six in Group L and four in Group G. There were no differences between groups in complications.

CONCLUSIONS

Superficial serratus anterior plane blocks are effective and safe in pain control in the immediate postoperative period for breast cancer surgery as a part of the multimodal approach. No significant differences were found one week and one month after surgery.

The effect of ultrasound-guided rectus sheath block on postoperative analgesia in robot assisted prostatectomy: A randomized controlled trial

BACKGROUND

Postoperative pain continues to represent an important problem even after minimally invasive robotic-assisted laparoscopic radical prostatectomy, which results in discomfort in the postoperative period and sometimes prolongs hospital stays. Regional anesthesia and analgesia techniques are used in addition to systemic analgesics with the multimodal approach in postoperative pain management. Ultrasound-guided fascial plane blocks are becoming increasingly important, especially in minimally invasive surgeries. Another important cause of discomfort is urinary catheter pain. The present randomized controlled study investigated the effect of rectus sheath block on postoperative pain and catheter-related bladder discomfort in robotic prostatectomy operations.

METHODS

This randomized controlled trial was conducted from March to August 2022. Written informed consent was obtained from all participants. Approval for the study was granted by the Clinical Research Ethics Committee. All individuals provided written informed consent, and adults with American Society of Anesthesiologists Physical Condition classification I to III planned for robotic prostatectomy operations under general anesthesia were enrolled. Following computer-assisted randomization, patients were divided into 2 groups, and general anesthesia was induced in all cases. Rectus sheath block was performed under general anesthesia and at the end of the surgery. No fascial plane block was applied to the patients in the non-rectus sheath block (RSB) group.Postoperative pain and urinary catheter pain were assessed using a numerical rating scale. Fentanyl was planned as rescue analgesia in the recovery room. In case of numerical rating scale scores of 4 or more, patients were given 50 µg fentanyl IV, repeated if necessary. The total fentanyl dose administered was recorded in the recovery room. IV morphine patient-controlled analgesia was planned for all patients. All patients' pain (postoperative pain at surgical site and urethral catheter discomfort) scores and total morphine consumption in the recovery unit and during follow-ups on the ward (3, 6, 12, and 24 hours) in the postoperative period were recorded.

RESULTS

Sixty-one patients were evaluated. Total tramadol consumption during follow-up on the ward was significantly higher in the non-RSB group. Fentanyl consumption in the postanesthesia care unit was significantly higher in the non-RSB group. Total morphine consumption was significantly lower in the RSB group at 0 to 12 hours and 12 to 24 hours. Total opioid consumption was 8.81 mg in the RSB group and 19.87 mg in the non-RSB group. A statistically significant decrease in urethral catheter pain was noted in the RSB group at all time points.

CONCLUSION

RSB exhibits effective analgesia by significantly reducing postoperative opioid consumption in robotic prostatectomy operations.

[Common and New Regional Anaesthesia Techniques Under Review - From Head to Abdomen]

By implementation of sonography regional anesthesia became more relevant in the daily practice of anesthesia and pain therapy. Due to visualized needle guidance ultrasound supports more safety during needle placement. Thereby new truncal blocks got enabled. Next to the blocking of specific nerve structures, plane blocks got established which can also be described as interfascial compartment blocks. The present review illustrates published and established blocks in daily practice concerning indications and the procedural issues. Moreover, the authors explain potential risks, complications and dosing of local anesthetics.

Factors to consider for fascial plane blocks' success in acute and chronic pain management

The outcome of fascial plane blocks (FPBs) has a certain variability that may depend on many factors, which can be divided into three main categories: operator-related, patient-related and drug-related. Operator-related factors include personal skills, choice of needle and injection modalities. Patient variables include anthropometric features, the type of targeted fascia, anatomical variants, patient positioning, muscle tone and breathing. Ultimately, efficacy, onset, and duration of fascial blocks may be affected by characteristics of the injected solution, including the type of local anesthetic, volume, concentration, pH, temperature and the use of adjuvants. In this article, we investigated all the factors that may influence the outcome of FPBs from a generic perspective, without focusing on any specific technique. Also, we provided suggestions to optimize techniques for everyday practitioners and insights to researchers for future studies.

Postoperative quality of recovery with erector spinae plane block or thoracolumbar interfascial plane block after major spinal surgery: a randomized controlled trial

PURPOSE

Major spinal surgery causes severe postoperative pain. The present randomized, controlled, prospective study tested the short- and long-term effects of thoracolumbar interfascial and erector spinae plane blocks on patient-centered outcomes for major lumbar spinal surgery.

METHODS

Sixty adult patients were randomly assigned to receive either bilateral thoracolumbar interfascial plane or erector spinae plane block after anesthesia induction using bupivacaine 0.25%, 20 mL. The primary outcome of this study was the Quality of Recovery-40 score in the postoperative 24th hour. Secondary outcomes were Comprehensive Complication Index scores, postoperative pain scores, opioid consumption, first rescue analgesic administration time, and complication incidence.

RESULTS

The recovery scores of both blocks at the postoperative 24th hour were similar, with a median thoracolumbar interfascial plane block of 178 (IQR 173-180) and an erector spinae plane block of 175 (IQR 168.7-182) (p = 0.717). Thoracolumbar interfascial plane block reduced area under the curve pain with movement over 24 h compared with erector spinae plane block (p = 0.024). The pain scores between the groups were similar at all time points (p > 0.05), except the 24th hour with movement in the thoracolumbar interfascial plane block compared with the erector spinae plane block [median 3 (IQR 2-4)] vs. 4 (IQR 3-5), respectively] (p = 0.019). No differences were recorded between the block groups regarding postoperative 24th-h oxycodone consumption, time to first opioid intake, and complication incidence (p > 0.05).

CONCLUSIONS

Both blocks resulted in similar quality of recovery in the postoperative 24-h period in major spinal surgery and were effective in terms of analgesia.

Double-Edge, Single-Edge, and Intermediate-Edge Ultrasound Sign and Correlation With Fascial Plane Block Efficacy: An Experimental Study

Introduction Ultrasound-guided fascial plane blocks are nowadays the gold standard technique for regional anesthesia and postoperative analgesia. Despite their high success rate, cases of partial or total failure of this method have been reported. This experimental study aims to address the corresponding ultrasound signs and their association with fascial plane block efficacy. Methods After capturing the appropriate sonographic image that included muscle layers and their fasciae, an 18-gauge epidural needle penetrated the cadaveric porcine tissue and was forwarded until the tip of the needle reached the target fascial plane. The infusion of methylthioninium chloride or methylene blue dye was performed, causing tissue hydro dissection. The documentation of the generated ultrasound images was followed by surgical exposure of the tip of the needle. Results The distribution of the dye into the plane of interest (double-edge sign) was equivalent to block success, whereas the single-edge sign (accumulation of the dye between fascia and epimysium) indicated total block failure. The intermediate-edge sign, a combination of the previous ultrasound signs, is related to partial failure of block performance. Conclusion The identification of the three novel sonographic signs is an accurate predictive factor of peripheral nerve block efficacy. The respective data are expected to aid the rapid improvement of interfascial plane block accuracy and techniques, leading to their more effective execution and simultaneously eliminating the failure rates. Thereby, the amelioration of intra and postoperative analgesia will be accomplished, expediting the patient's hospital discharge and reducing or even avoiding opioid consumption.

A non-inferiority study comparing the ultrasound-guided parasacral with a novel greater ischiatic notch plane approach in canine cadavers

OBJECTIVE

To describe the gross and ultrasound anatomy of the parasacral region and an ultrasound-guided greater ischiatic notch (GIN) plane approach aimed at staining the lumbosacral trunk (LST) in canine cadavers. To evaluate if the ultrasound-guided GIN plane approach is non-inferior to the previously described ultrasound-guided parasacral approach at staining the LST.

STUDY DESIGN

Prospective, randomized, non-inferiority experimental anatomic study.

ANIMALS

A total of 17 (23.9 ± 5.2 kg) mesocephalic canine cadavers.

METHODS

Anatomic and echographic landmarks, and the feasibility of performing a GIN plane technique were evaluated using two canine cadavers. The remaining 15 cadavers had each hemipelvis randomly assigned to be administered either parasacral or GIN plane injection of 0.15 mL kg-1 dye solution. The parasacral region was dissected after injections to assess the staining of LST, cranial gluteal nerve, pararectal fossa and pelvic cavity. The stained LST were removed and processed for histological evaluation of intraneural injections. A one-sided z-test for non-inferiority (non-inferiority margin -14%) was used to statistically evaluate the success of the GIN plane versus the parasacral approach. Data were considered statistically significant when p < 0.05.

RESULTS

The GIN plane and parasacral approach stained the LST in 100% and 93.3% of the injections, respectively. The success rate difference between treatments was 6.7% [95% confidence interval, -0.6 to 19.0%; p < 0.001 for non-inferiority]. The GIN plane and parasacral injections stained the LST for 32.7 ± 16.8 mm and 43.1 ± 24.3 mm, respectively (p = 0.18). No evidence of intraneural injection was found.

CONCLUSIONS AND CLINICAL RELEVANCE

The ultrasound-guided GIN plane technique resulted in nerve staining that was non-inferior to the parasacral technique and may be considered an alternative to the parasacral approach to block the LST in dogs.

Comparison of ultrasound-guided transversalis fascia plane block and anterior quadratus lumborum block in patients undergoing caesarean delivery: a randomized study

BACKGROUND

Cesarean section is becoming increasingly common. Well-managed postoperative analgesia improves patient comfort while encouraging early ambulation and breastfeeding. The analgesic efficacy of transversalis facial plane block (TFPB) vs. anterior quadratus lumborum block (QLB) was compared in this study.

METHODS

We analyzed the data of 49 pregnant women (gestation, ≥ 37weeks; age, 18-45years) scheduled for elective cesarean delivery (CD) under general anesthesia. They were randomly divided into TFPB and anterior QLB groups. All blocks were administered bilaterally with 25mL of 0.25% bupivacaine under ultrasound guidance prior to extubation. Postoperative morphine consumption and numerical rating scale (NRS) pain scores (static and dynamic [during coughing]) were recorded at 1, 3, 6, 9, 12, 18, and 24h.

RESULTS

There was no difference in postoperative morphine consumption between the groups at the third, sixth, and ninth hours, but the anterior QLB group consumed less morphine at the 12th, 18th, and 24th hours. Except for the first hour, resting and dynamic NRS scores were comparable between the groups. The first-hour resting and dynamic NRS scores were lower in the TFPB group (resting NRS, anterior QLB group, median [interquartile range], 2 [2-3] vs. TFPB group, 2 [0-2], p = 0.046; dynamic NRS, anterior QLB group, median [interquartile range], 3 [2-4] vs. TFPB group 2 [0-3], p = 0.001).

CONCLUSIONS

In patients undergoing CD, anterior QLB decreased morphine consumption in the late period (9-24h) compared to TFPB, while pain scores were similar between both groups. The reduction in morphine consumption was statistically significant, but not clinically significant.

Serratus anterior and pectoralis plane blocks for robotically assisted mitral valve repair: a randomised clinical trial

BACKGROUND

Minimally invasive cardiac surgery provokes substantial pain and therefore analgesic consumption. The effect of fascial plane blocks on analgesic efficacy and overall patient satisfaction remains unclear. We therefore tested the primary hypothesis that fascial plane blocks improve overall benefit analgesia score (OBAS) during the initial 3 days after robotically assisted mitral valve repair. Secondarily, we tested the hypotheses that blocks reduce opioid consumption and improve respiratory mechanics.

METHODS

Adults scheduled for robotically assisted mitral valve repairs were randomised to combined pectoralis II and serratus anterior plane blocks or to routine analgesia. The blocks were ultrasound-guided and used a mixture of plain and liposomal bupivacaine. OBAS was measured daily on postoperative Days 1-3 and were analysed with linear mixed effects modelling. Opioid consumption was assessed with a simple linear regression model and respiratory mechanics with a linear mixed model.

RESULTS

As planned, we enrolled 194 patients, with 98 assigned to blocks and 96 to routine analgesic management. There was neither time-by-treatment interaction (P=0.67) nor treatment effect on total OBAS over postoperative Days 1-3 with a median difference of 0.08 (95% confidence interval [CI]: -0.50 to 0.67; P=0.69) and an estimated ratio of geometric means of 0.98 (95% CI: 0.85-1.13; P=0.75). There was no evidence of a treatment effect on cumulative opioid consumption or respiratory mechanics. Average pain scores on each postoperative day were similarly low in both groups.

CONCLUSIONS

Serratus anterior and pectoralis plane blocks did not improve postoperative analgesia, cumulative opioid consumption, or respiratory mechanics during the initial 3 days after robotically assisted mitral valve repair.

CLINICAL TRIAL REGISTRATION

NCT03743194.

Anatomical study of the adductor canal: three-dimensional micro-computed tomography, histological, and immunofluorescence findings relevant to neural blockade

BACKGROUND

A precise anatomical understanding of the adductor canal (AC) and its neural components is essential for discerning the action mechanism of the AC block. We therefore aimed to clarify the detailed anatomy of the AC using micro-computed tomography (micro-CT), histological evaluation, and immunofluorescence (IF) assays.

METHODS

Gross dissections of 39 thighs provided morphometric data relevant to injection landmarks. Serial sectional images of the AC were defined using micro-CT and ultrasonography. The fascial and neural structures of the AC proper were histologically evaluated using Masson's trichrome and Verhoeff-Van Gieson staining, and double IF staining using choline acetyltransferase (ChAT) and neurofilament 200 antibodies.

RESULTS

The posteromedial branch insertion of the nerve to vastus medialis (NVM) into the lateral border of the AC proper was lower (14.5 ± 2.4 cm [mean ± SD] above the base of the patella) than the origin of the proximal AC. The AC consists of a thin subsartorial fascia in the proximal region and a thick aponeurosis-like vastoadductor membrane in the distal region. In the proximal AC, the posteromedial branch of the NVM (pmNVM) consistently contained both sensory and motor fibers, and more ChAT-positive fibers were observed than in the saphenous nerve (27.5 ± 11.2 / 104 vs. 4.2 ± 2.6 / 104 [counts/µm2], P < 0.001).

CONCLUSIONS

Anatomical differences in fascial structures between the proximal and distal AC and a mixed neural component of the neighboring pmNVM have been visualized using micro-CT images, histological evaluation, and IF assays.

External Oblique Intercostal Block for Living Kidney Donor Open Nephrectomy: A Case Series

The external oblique intercostal (EOI) block is a novel regional technique that provides analgesia for upper abdominal incisions. We performed single-injection and continuous EOI blocks in living kidney donors who underwent open nephrectomy. In this case series, we report our experience with pain management using this technique in five patients at our centre. EOI block resulted in good pain relief in our patients. The median (IQR) numerical rating scale score was 3 (1-6) at rest immediately after the end of the surgery, predominantly visceral. We want to highlight the benefits regarding pain management of the association of EOI block with conventional therapy.

Three-Dimensional Imaging of Commonly Performed Peripheral Blocks: Using a Handheld Point-of-Care Ultrasound System

Background

Handheld ultrasound devices have become popular among clinicians due to their affordability and compatibility with tablets and smartphones. Several handheld ultrasound devices have the capability to construct three-dimensional (3D) images using a traditional two-dimensional (2D) ultrasound transducer.

Objectives

The current study aimed to construct 3D images of common peripheral nerve and fascial plane blocks using a handheld ultrasound device with a 2D ultrasound probe.

Methods

A total of 10 patients who were scheduled to receive ultrasound-guided peripheral nerve blocks for outpatient surgery and classified as the American Society of Anesthesiologists physical status I or II with a body mass index of ≤ 30 kg/m² were included in the study. Patients who presented with anatomical variations during the initial ultrasound scanning were excluded.

Results

This study successfully constructed 3D images of 10 peripheral nerve blocks. The average time to complete each 3D scan was less than 5 seconds per attempt, with fascial plane blocks requiring twice the amount of time to complete. All the nerve blocks provided effective postoperative analgesia without complications. The 3D images were successfully captured in all patients.

Conclusions

The 3D images provide clinicians with valuable information on the anatomical boundaries of the injectate that can further direct needle direction and placement of local anesthetic to achieve visual confidence of anesthetic spread.

An Expert Review of Chest Wall Fascial Plane Blocks for Cardiac Surgery

The recent integration of regional anesthesia techniques into the cardiac surgical patient population has become a component of enhanced recovery after cardiac surgery pathways. Fascial planes of the chest wall enable single-injection or catheter-based infusions to spread local anesthetic over multiple levels of innervation. Although median sternotomy remains a common approach to cardiac surgery, minimally invasive techniques have integrated additional methods of performing cardiac surgery. Understanding the surgical approach and chest wall innervation is crucial to success in choosing the appropriate chest wall block. Parasternal intercostal plane techniques (previously termed "pectointercostal fascial plane" and "transversus thoracic muscle plane") provide anterior chest and ipsilateral sternal coverage. Anterolateral chest wall coverage is feasible with the interpectoral plane and pectoserratus plane blocks (previously termed "pectoralis") and superficial and deep serratus anterior plane blocks. The erector spinae plane block provides extensive coverage of the ipsilateral chest wall. Any of these techniques has the potential to provide bilateral chest wall analgesia. The relative novelty of these techniques requires ongoing research to be strategic, thoughtful, and focused on clinically meaningful outcomes to enable widespread evidence-based implementation. This review article discusses the key perspectives for performing and assessing chest wall blocks in a cardiac surgical population.

Assessment of cardiotoxicity and plasma ropivacaine concentrations after serratus intercostal fascial plane block in an experimental model

Serratus intercostal fascial plane block (SIFPB) has emerged as an alternative to paravertebral block in breast surgery. It involves the administration of high volumes and doses of local anesthetics (LA) that can potentially reach toxic levels. Ropivacaine is widely used in thoraco-fascial blocks; however, there is no information on the plasma concentrations attained after SIPFB and whether they are associated with cardiotoxicity. Plasma concentrations of ropivacaine and its electrophysiological effects were evaluated in eight pigs after bilateral SIFPB with ropivacaine in doses of 3 mg/kg. Plasma concentrations, electrophysiological and hemodynamic parameters were measured sequentially for the following 180 min until the end of the study. The area under the curve, the maximum plasma concentration (C_max) and the time to reach C_max (t_max) were calculated. The median arterial ropivacaine concentration C_max was, 2.34 [1.40 to 3.74] µg/ml. The time to reach the highest concentration was 15 [10 to 20] min. Twenty-five percent of the animals had arterial concentrations above the lower limit concentration of ropivacaine for LA systemic toxicity (3.4 µg/ml). No alterations were observed in the electrophysiological or electrocardiographic parameters except for a prolongation of the QTc interval, from 489 ± 30 to 544 ± 44 ms (Δ11.38 ± 6%), P = 0.01. Hemodynamic parameters remained in the physiological range throughout the study. SIFPB with ropivacaine in doses of 3 mg/kg has reached potentially toxic levels, however, it has not been associated with adverse electrophysiological or hemodynamic effects.

Recent advancements in regional anaesthesia

Patient safety, improved quality of care, and better patient satisfaction and functional outcomes are currently the topmost priorities in regional anaesthesia (RA) and all advancements in RA move in this direction. Ultrasonography-guided central neuraxial and peripheral nerve blocks, intracluster and intratruncal injections, fascial plane blocks, diaphragm-sparing blocks, use of continuous nerve block techniques, and continuous local anaesthetic wound infiltration catheters are now topics of popular clinical interest. The safety and efficacy of nerve blocks can be improved with the help of injection pressure monitoring and the incorporation of advanced technology in the ultrasound machine and needles. Novel procedure-specific and motor-sparing nerve blocks have come up. The anaesthesiologist of the current era, with a good understanding of the sonoanatomy of the target area and the microarchitecture of nerves, along with the backup of advanced technology, can be very successful in performing RA techniques. RA is rapidly evolving and revolutionising the practice of anaesthesia.

Single ultrasound-guided thoracic paravertebral block with a large volume of anesthetic for microwave ablation of lung tumors

Objective

To compare single ultrasound-guided thoracic paravertebral block (TPVB) using a large volume of anesthetic with local anesthesia (LA) in computed tomography (CT)-guided pulmonary microwave ablation.

Subjects and methods

Eighty patients who underwent CT-guided microwave ablation of pulmonary tumors were randomly divided into the TPVB group and the LA group. Patients of the TPVB group were anesthetized with a single injection of a large volume (40 ml) of 0.375% ropivacaine injection at T4, and those of the LA group had local infiltration by the surgeon at the puncture site, and emergency rescue with propofol injection was administered when the patient could not tolerate pain in either group. The following variables were recorded in both groups: general conditions; volume of propofol injection for emergency rescue during ablation; visual analog scale (VAS) scores during ablation and at 0, 2, 12, and 24 h after ablation; the need to use analgesics for rescue within 24 h after ablation; number of ablations; number of punctures performed by the surgeon; patient’s movements during puncturing; and puncturing-associated complications.

Results

Compared with the TPVB group, the amount of emergency use of propofol injection was significantly more in the LA group (P < 0.05). There were no significant differences in the VAS scores recorded intraoperatively and at 0, 2, 12, and 24 h after ablation between the two groups (P > 0.05). There was a significant difference in the patient’s movements upon puncturing between the two groups (P < 0.05), but there were no significant differences in the numbers of punctures and ablations between the two groups (P > 0.05). The number of patients using analgesics within 24 h after the operation was also more in the LA group than in the TPVB group, and the difference between the two groups was statistically significant (P < 0.05).

Conclusion

Single ultrasound-guided TPVB with a large volume of anesthetic offers effective analgesia for microwave ablation of lung tumors, helping the patient cooperate with the operating surgeon to reduce injury from multiple lung punctures. Further studies are recommended to validate these findings.

Development of Enhanced Recovery After Surgery (ERAS) protocols in veterinary medicine through a one-health approach: the role of anesthesia and locoregional techniques

Enhanced Recovery After Surgery (ERAS) is a new and emerging concept in human medicine that involves rethinking the preoperative, intraoperative, and postoperative periods. The ultimate, overarching aim is to improve patient outcome following surgery and, thus, return to a normal daily routine as soon as possible. The development and implementation of locoregional anesthetic techniques in humans is one of the key elements driving these protocols. In veterinary medicine, we are no exception: the rapidly growing interest, development, and refinement of these techniques in our veterinary species is changing the way we think of anesthesia and analgesia. The potential real benefits are yet to be determined, as this concept is implemented into our veterinary hospitals in general, and our surgical patients in particular, in a more systematic and routine way. In this article, we will introduce the reader to the concept of ERAS protocols and the role of regional anesthesia in some common surgical procedures.

Ultrasound-guided erector spinae plane block for postoperative analgesia in patients after liver surgery: A systematic review and meta-analysis on randomized comparative studies

OBJECTIVE

To compare the analgesic efficacy and feasibility of erector spinae plane block (ESPB) with non-block care or other blocks in patients undergoing liver surgery.

METHOD

A meta-analysis of randomized controlled trials (RCTs) that compared ESPB to non-block care or local infiltration analgesia (LIA), intrathecal morphine (ITM) and quadratus lumborum block (QLB) for postoperative analgesia in liver surgery patients.

RESULTS

Six RCTs containing 392 patients were included. This meta-analysis found that ESPB did not significantly reduce postoperative 8 h [mean standard (MD) 0.20; 95% (confidence interval) CI: -1.62, 2.01; P = 0.83; I² = 99%] and 24 h [MD 0.10; 95% CI: -0.91, 1.11; P = 0.84; I² = 97%] resting pain scores in patients undergoing liver surgery compared to control groups. Furthermore, ESPB had no effect on postoperative 24 h cumulative opioid consumption [MD 1.74; 95% CI: 3.43, 6.91; P = 0.51; I² = 95%] or sleep quality [OR 1.00; 95% CI: 0.43, 2.35; P 0.99; I² = 0%]. In contrast, ESPB reduced postoperative 48 h resting pain score [MD -0.77; 95% CI -1.56, 0.02; P = 0.05; I² = 96%], the incidence of postoperative nausea and vomiting (PONV) [OR 0.29; 95% CI 0.18, 0.48; P = 0.001; I² = 0%]. Interestingly, in two RCTs, ESPB showed a higher incidence of shoulder pain compared to ITM [OR 2.89; 95%CI 1.03 to 8.09; P = 0.04; I² = 0%]. There have been no reports of complications from ESPB or other blocks.

CONCLUSION

Current literature supported that ESPB had no significant difference in analgesic efficacy in liver surgery patients compared to LIA, ITM, and QLB. More evidences, preferably from high quality RCTs are required to confirm these finding.

Erector Spinae Plane Catheter Analgesia in Minimally Invasive Mitral Valve Surgery: A Retrospective Case-Control Study for Inclusion in an Enhanced Recovery Program

Background. A retrospective case-control study was conducted to assess the feasibility of erector spinae plane (ESP) block as part of a multimodal enhanced recovery program for patients undergoing minimally invasive mitral valve replacement surgery. Methods. This retrospective analysis was conducted at a single center between January and August 2019. 61 patients were included; 23 received ESP and 38 did not. Erector spinae catheters (ESCs) were placed preoperatively, using a loading dose of 30 mL .5% ropivacaine, followed by an infusion of .2% ropivacaine at 10 mL/h throughout the study period. Primary outcome was 48-hour opioid consumption. Secondary outcomes included intraoperative morphine equivalents, extubation within 24 hours, reintubation, ICU length of stay and hospital length of stay and 30-day mortality. Results. Median [inter-quartile range] of the postoperative morphine milligram equivalents (MMEs) in the first 48 hours was 70[45-121] MMEs in the ESC) group, and 109[70-148] MMEs in the no ESC group (P-value = .16). No significant difference was observed in intraoperative morphine equivalents, extubation within 24 hours or ICU length of stay. The ESC group had shorter hospital length of stay (6.0 vs 7.0 days, P-value = .043). Conclusion. This study found a statistically insignificant, though potentially clinically significant reduction in postoperative opioid consumption. A reduced hospital length of stay as well as an acceptable safety profile was also observed in the ESC group. An adequately powered, prospective trial is warranted to accurately assess the potential role for ESP catheters for patients undergoing minimally invasive mitral valve surgery.

Considerations for Better Management of Postoperative Pain in Light of Chronic Postoperative Pain: A Narrative Review

Chronic postoperative pain (CPOP) is prevalent, with particularly high rates in breast surgery, thoracotomy, and amputation. As the world emerges from the coronavirus disease 2019 (COVID-19) lockdowns, it is expected that there will be an increase in surgical procedures, elevating the importance of preventing CPOP in the coming years. Risk factors are emerging to better stratify patients at high risk for CPOP. Perioperative analgesia plays an important role in managing acute postoperative pain and in some cases may limit its transition to CPOP. Acute postoperative pain is adaptive, normal, expected, and has a well-defined trajectory, while CPOP is maladaptive and, as a form of chronic pain, is challenging to treat. Good analgesia, early ambulation, and rehabilitation efforts may be helpful in preventing CPOP following certain surgeries. Enhanced Recovery After Surgery (ERAS) protocols present guidance to help promote recovery and prevent CPOP.