A prospective, randomized comparison of ultrasonographic visualization of proximal intercostal block vs paravertebral block

Analysis and Tracking of Intra-Needle Ultrasound Pleural Signals for Improved Anesthetic Procedures in the Thoracic Region

BACKGROUND

Ultrasonography is commonly employed during thoracic regional anesthesia; however, its accuracy can be affected by factors such as obesity and poor penetration through the rib window. Needle-sized ultrasound transducers, known as intra-needle ultrasound (INUS) transducers, have been developed to detect the pleura and fascia using a one-dimensional radio frequency mode ultrasound signal. In this study, we aimed to use time-frequency analysis to characterize the pleural signal and develop an automated tool to identify the pleura during medical procedures.

METHODS

We developed an INUS system and investigated the pleural signal it measured by establishing a phantom study, and an in vivo animal study. Signals from the pleura, endothoracic fascia, and intercostal muscles were analyzed. Additionally, we conducted time- and frequency-domain analyses of the pleural and alveolar signals.

RESULTS

We identified the unique characteristics of the pleura, including a flickering phenomenon, speckle-like patterns, and highly variable multi-band spectra in the ultrasound signal during the breathing cycle. These characteristics are likely due to the multiple reflections from the sliding visceral pleura and alveoli. This automated identification of the pleura can enhance the safety for thoracic regional anesthesia, particularly in difficult cases.

CONCLUSIONS

The unique flickering pleural signal based on INUS can be processed by time-frequency domain analysis and further tracked by an auto-identification algorithm. This technique has potential applications in thoracic regional anesthesia and other interventions. However, further studies are required to validate this hypothesis. Key Points Summary: Question: How can the ultrasound pleural signal be distinguished from other tissues during breathing?

FINDINGS

The frequency domain analysis of the pleural ultrasound signal showed fast variant and multi-band characteristics. We suggest this is due to ultrasound distortion caused by the interface of multiple moving alveoli. The multiple ultrasonic reflections from the sliding pleura and alveoli returned in variable and multi-banded frequency. Meaning: The distinguished pleural signal can be used for the auto-identification of the pleura for further clinical respiration monitoring and safety during regional anesthesia. Glossary of Terms: intra-needle ultrasound (INUS); radio frequency (RF); short-time Fourier transform (STFT); intercostal nerve block (ICNB); paravertebral block (PVB); pulse repetition frequency (PRF).

Assessment of ultrasound-guided intercostal nerve block for acute herpes zoster and its' possible prophylaxis for postherpetic neuralgia: a retrospective and case-controlled trial

Background

This study aimed to compare the intercostal nerve block (ICNB) and thoracic paravertebral block (TPVB) for acute herpes zoster-associated pain (ZAP) and possible prophylaxis for post-herpetic neuralgia (PHN).

Methods

This study enrolled 128 patients with ZAP. Their records were stratified into standard antiviral treatment (AVT) plus US-guided TPVB (the TPVB group), AVT plus US-guided ICNB (the ICNB group) or AVT alone (the control group). Herpes zoster (HZ)-related burden of illness (HZ-BOI) within the post-procedural 30 days was defined as the primary endpoint, determined by a composite of pain severity and follow-up duration. Procedure time, rescue analgesic requirement, PHN incidence, health-related quality of life and side effects were also recorded.

Results

Significantly lower HZ-BOI-AUC30 was reported in the TPVB and ICNB groups as compared to the control group, with a mean difference of 57.5 (P < 0.001) and 40.3 (P = 0.003), respectively. However, there was no difference between the TPVB and ICNB groups (P = 0.978). Both TPVB and ICNB reported significantly greater improvements in PHN incidence, EQ-5D-3L scores and rescue analgesic requirements during follow-up, as opposed to the control AVT. Shorter procedure time was observed in ICNB as compared to TPVB (16.47 ± 3.39 vs. 11.69 ± 2.58, P < 0.001).

Conclusions

Both US-guided TPVBs and ICNBs were effective for ZAP, and accounted for possible prophylaxis for PHN, as compared to AVT alone. The ICNB approach could be recommended as an alternative to conventional TPVB with a better consumed procedure time and side effect profile.a.

The impact of paravertebral nerve blockade on postoperative surgical site wound pain management in patients undergoing video-assisted thoracoscopic surgery for pulmonary carcinoma resection

Management of postoperative pain is of vital importance for patients undergoing Video-Assisted Thoracoscopic Surgery (VATS) for Pulmonary Carcinoma Resection. The study evaluates the impact of Paravertebral Nerve Blockade (PNB) in conjunction with general anaesthesia on postoperative pain relief, as compared with general anaesthesia alone. A retrospective analysis was carried out from May 2020 to May 2023, involving 100 patients with pathologically confirmed pulmonary carcinoma. The patients were divided into two groups: a control group that received general anaesthesia and an observation group that received a combination of general anaesthesia and PNB. The intensity of postoperative pain was assessed at various time intervals using the visual analogue scale (VAS), while the effectiveness of patient-controlled analgesia was also evaluated. Additionally, the study examined the incidence rates of chronic pain in the postoperative period. Statistical analysis was performed using IBM SPSS version 27.0. Significant reductions in VAS scores for both resting and cough-induced pain were observed in the observation group at 2 and 6 h post-operation (p < 0.01). However, the difference diminished over time. The observation group had fewer patient-controlled analgesia activations and required lower dosages of hydromorphone at both 24- and 48-h post-operation. The incidence of chronic pain was also significantly lower in the observation group (24.00%) compared with the control group (54.00%) (p < 0.01). PNB, when administered in combination with general anaesthesia, significantly reduces immediate postoperative pain and the requirement for additional analgesics in patients undergoing VATS for pulmonary carcinoma resection. The effect diminishes over time but has a lasting impact on reducing the incidence of chronic postoperative pain.

Safety and Efficacy of Ultrasound-Guided Sympathetic Blockade by Proximal Intercostal Block in Electrical Storm Patients

BACKGROUND

Electrical storm (ES) patients who fail standard therapies have a high mortality rate. Previous studies report effective management of ES with bedside, ultrasound-guided percutaneous stellate ganglion block (SGB). We report our experience with sympathetic blockade administered via a novel alternative approach: proximal intercostal block (PICB). Compared with SGB, this technique targets an area typically free of other catheters and support devices, and may pose less strict requirements for anticoagulation interruption, along with lower risk of focal neurological side effects.

OBJECTIVES

The authors sought to describe the safety and efficacy of PICB in patients with refractory ES.

METHODS

We reviewed our institutional data on ES patients who underwent PICB between January 2018 and February 2023 to analyze procedural safety and short- and long-term outcomes.

RESULTS

A total of 15 consecutive patients with ES underwent PICB during this period. Of those, 11 patients (73.3%) were maintained on PICB alone, and 4 patients (26.6%) were maintained on combined block with SGB and PICB. Overall, 72.7% patients who were maintained on PICB alone and 77.8% patients who were maintained on bilateral PICB had excellent arrhythmia suppression. After PICB, implantable cardioverter-defibrillator therapies were significantly reduced (P < 0.05), with 93.3% of patients receiving PICB having no implantable cardioverter-defibrillator shock until discharge or heart transplant. Anticoagulation was continued in all patients and there were no procedure-related complications. Apart from mild transient neurological symptoms seen in 3 patients, no significant neurological or hemodynamic sequelae were observed.

CONCLUSIONS

In patients with refractory ES, continuous PICB provided safe and effective sympathetic block (77.8% ventricular arrhythmia suppression), achievable without interruption of anticoagulation, and without significant side effects.

A Case Report of Elective Bilateral Proximal Intercostal Blocks Used to Prevent Arrhythmia in Catecholaminergic Polymorphic Ventricular Tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmogenic disorder characterized by episodes of polymorphic ventricular tachycardia. Clinically, patients who have CPVT present with juvenile sudden death or stress-induced syncope. We present a case of an 18-year-old girl with CPVT resistant to traditional pharmacotherapies. Instead of a typical stellate ganglion block (SGB), the patient underwent bilateral continuous proximal intercostal blocks that successfully inhibited arrhythmogenic events. This therapeutic method may provide an alternative to SGBs and demonstrates proof of concept for an early elective intervention to be included in the diagnostic and therapeutic algorithm for patients with CPVT.

Application of ultrasound-guided thoracic paravertebral block or intercostal nerve block for acute herpes zoster and prevention of post-herpetic neuralgia: A case-control retrospective trial

OBJECTIVES

Ultrasound (US)-guided intercostal nerve block (ICNB) is an easier approach with a very low incidence of complications for different surgeries; nevertheless, only a few studies estimate the effect of ICNB for acute HZ. To explore the US-guided ICNB for management of herpes zoster (HZ)-related acute pain and possible prophylaxis for post-herpetic neuralgia (PHN) taking the conventional thoracic paraverteral block (TPVB) as control.

METHODS

A total of 128 patients with HZ were retrospectively stratified into antiviral treatment (AVT) plus US-guided TPVB (TPVB group), AVT plus US-guided ICNB (ICNB group) or AVT alone (control group) based on the treatment they received. HZ-related illness burden (HZ-BOI) over 30 days after inclusion as the primary endpoint was determined by a severity-by-duration composite pain assessment. Rescue analgesic requirement, health-related quality of life, PHN incidence, and adverse events were also recorded.

RESULTS

Significantly lower HZ-BOI scores within post-procedural 30 days using the area under the curve were reported with TPVB and ICNB compared with the control group: mean difference of 57.5 (p < 0.001) and 40.3 (p = 0.003). No difference was reported between TPVB and ICNB (p = 1.01). Significant greater improvements in PHN incidence, EQ-5D-3L scores, and rescue analgesic requirements were observed during follow-up favoring two trial groups, while comparable between two trial groups. No serious adverse events were observed.

CONCLUSIONS

US-guided ICNBs were as effective as TPVBs for acute HZ. The ICNB technique was an easier and time-efficient approach as opposed to conventional TPVB, which might be encouraged as a more accessible preemptive mean for preventing PHN.

Erector spinae plane block versus local infiltration anaesthesia for transforaminal percutaneous endoscopic discectomy: A prospective randomised controlled trial

BACKGROUND

Around 60%-80% of the population suffers from back pain, making it one of the most common health complaints. Transforaminal percutaneous endoscopic discectomy (TPED) is an effective treatment for low back pain that can be performed using different anaesthesia techniques. Our primary objective was to test the hypothesis that bilateral Erector spinae plane block (ESP) plus sedation is equally effective as traditional local infiltration anaesthesia plus sedation in TPED.

MATERIALS AND METHODS

Fifty-two patients undergoing TPED were randomly assigned to 2 groups: G1 - intravenous sedation with local infiltration anaesthesia; G2 - intravenous sedation with bilateral ESP.

PRIMARY OUTCOME

volume of fentanyl and propofol administered during surgery.

SECONDARY OUTCOMES

adverse events during sedation reported using the World Society of Intravenous Anaesthesia (SIVA) adverse sedation event tool, level of postoperative sedation measured on the Richmond Agitation-Sedation Scale (RASS), intensity of postoperative pain on a visual analogue scale (VAS), mechanical pain threshold (MPT) measured with von Frey monofilaments on both lower extremities, patient satisfaction with analgesia on 5-point Likert scale.

RESULTS

Volume of fentanyl, propofol, and level of postoperative sedation was significantly lower in G2 (p < 0.001). There was no difference between groups in intensity of pain, patient satisfaction with analgesia, and mechanical pain threshold after surgery. There were no adverse events in G2, but in G1 2 patients presented minimal risk descriptors, 5 presented minor risk descriptors, and 1 presented sentinel risk descriptors that required additional medication or rescue ventilation.

CONCLUSIONS

The ESP was equal to local infiltration anaesthesia in terms of intensity of pain, mechanical pain threshold after surgery, and patient satisfaction; however, ESP reduced the volume of intraoperative fentanyl and propofol, thereby reducing the adverse effects of sedation.

Comparison of the efficacy of ultrasound guided pectoralis-II block and intercostal approach to paravertebral block (proximal intercostal block) among patients undergoing conservative breast surgery: A randomised control study

Background and Aims

Regional anesthesia techniques have attributed a multimodal dimension to pain management after breast surgery. The intercostal approach to paravertebral block has been gaining interest, becoming an alternative to conventional paravertebral block, devoid of complexities in its approach, being recognized as the proximal intercostal block. Parallel to the widespread acceptance of fascial plane blocks in breast surgery, pectoralis II block has emerged as being non-inferior to paravertebral block. The aim of this study was to evaluate the efficacy of two independent fascial plane blocks, proximal intercostal block and pectoralis II block, in breast conservation surgery.

Material and Methods

This prospective, randomized control, pilot study included 40 patients, randomly allocated among two groups: proximal intercostal block and pectoralis II block.

Results

The pectoralis II block group had significantly lower pain scores at rest in the immediate postoperative period but became comparable with the proximal intercostal block group in the late postoperative period. Pain scores on movement though were lower at 0 h postoperatively and became comparable with the proximal intercostal block group subsequently. Although the pectoralis II group had earlier recovery in the post-anesthesia care unit, the overall time to discharge from the hospital was comparable and not influential. Both groups had high patient satisfaction scores and similar perioperative opioid consumption. Sedation, time to first rescue analgesia, and postoperative nausea vomiting scores were comparable.

Conclusion

Fascial plane blocks in the form of pectoralis II and proximal intercostal block facilitate pain alleviation, early return to shoulder arm exercise, and enhanced recovery, which should render them to be incorporated into multimodal interdisciplinary pain management in breast conservation surgery.

Investigating 3D-printed disk compressing against skin for pain relief in intradermal infiltration anesthesia: a randomized controlled trial

BACKGROUND

Pain intensity may be varied during the needle advancing through different skin layers, injection into the intradermal layer may exclude mixed pain from deeper planes. This study aimed to investigate whether compressing a three-dimensional (3D)-printed disk against the skin may relieve pain associated with intradermal injection of local anesthetic which mimics the skin test procedure.

METHODS

After institutional review board approval, 3D-printed disks with projections were designed for this study. Enrolled patients were randomized to receive either a disk compressing against the axillary skin during the intradermal injection of local anesthesia (compressing disk group) or an intradermal injection of local anesthesia without any compression (no compressing disk group). The primary outcomes were pain intensity (100-mm visual analog scale) and satisfaction (5-point Likert scale) as assessed by patients.

RESULTS

Ninety patients with American Society of Anesthesiologists I-II physical status receiving intradermal local anesthesia prior to an ultrasound-guided axillary approach were included. Eighty-seven patients completed the study, with 44 and 43 patients in disk and no disk groups, respectively. Pain scores were significantly different (P < 0.001) in compressing disk (median, 10; IQR, 5-20) and no compressing disk (median, 30; IQR, 20-40) groups. The median satisfaction score was 5 in both groups. No complications occurred during follow-up.

CONCLUSION

Compressing a 3D-printed disk against the skin may reduce intradermal needle pain and offers an effective alternative for nerve block induction.

Efficacy of regional anesthesia techniques for postoperative analgesia in patients undergoing major oncologic breast surgeries: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

The optimal regional technique to control pain after breast cancer surgery remains unclear. We sought to synthesize available data from randomized controlled trials comparing pain-related outcomes following various regional techniques for major oncologic breast surgery.

METHODS

In a systematic review and network meta-analysis, we searched trials in PubMed, Embase Scopus, Medline, Cochrane Central and Google Scholar, from inception to 31 July 2020, for commonly used regional techniques. The primary outcome was the 24-hr resting pain score measured on a numerical rating score of 0-10. We used surface under the cumulative ranking curve (SUCRA) to establish the probability of an intervention ranking highest. The analysis was performed using the Bayesian random effects model, and effect sizes are reported as 95% credible interval (Crl). We conducted cluster-rank analysis by combining 24-hr pain ranking with 24-hr opioid use or incidence of postoperative nausea and vomiting.

RESULTS

Seventy-nine randomized controlled trials containing 11 different interventions in 5,686 patients were included. The SUCRA values of the interventions for 24-hr resting pain score were continuous paravertebral block (0.83), serratus anterior plane block (0.76), continuous wound infusion (0.76), single-level paravertebral block (0.68), erector spinae plane block (0.59), modified pectoral block (0.49), intercostal block (0.45), multilevel paravertebral block (0.41), wound infiltration (0.33), no intervention (0.12), and placebo (0.08). When compared with placebo, the continuous paravertebral block (mean difference, 1.26; 95% Crl, 0.43 to 2.12) and serratus anterior plane block (mean difference, 1.12; 95% Crl, 0.32 to 1.9) had the highest estimated probability of decreasing 24-hr resting pain scores. Cluster ranking analysis combining 24-hr resting pain scores and opioid use showed that most regional analgesia techniques were more effective than no intervention or placebo. Nevertheless, wound infiltration and continuous wound infusion may be the least effective active interventions for reducing postoperative nausea and vomiting.

CONCLUSION

Continuous paravertebral block and serratus anterior plane block had a high probability of reducing pain at 24 hr after major oncologic breast surgery. The certainty of evidence was moderate to very low. Future studies should compare different regional anesthesia techniques, including surgeon-administered techniques such as wound infiltration or catheters. Trials comparing active intervention with placebo are unlikely to change clinical practice.

STUDY REGISTRATION

PROSPERO (CRD42020198244); registered 19 October 2020.

Persistent Post-Mastectomy Pain: The Impact of Regional Anesthesia Among Patients with High vs Low Baseline Catastrophizing

BACKGROUND

Persistent post-mastectomy pain (PPMP) varies both in its severity and impact, with psychosocial factors such as catastrophizing conferring greater risk. Preoperative regional anesthesia (RA) is an important nonopioid therapy, but with variable success at preventing PPMP in previous reports. We previously reported that RA was associated with lower acute post-mastectomy pain and opioid use, but more prominently among patients with higher baseline catastrophizing. The current longitudinal investigation at 3, 6, and 12 months postop aimed to detect differential long-term impact of RA on PPMP among patients with high vs low catastrophizing.

METHODS

In this prospective observational study, patients (n = 123) completed preoperative psychosocial assessment and underwent mastectomy either with (n = 56) or without (n = 67) preoperative RA. Generalized estimating equation (GEE) regression analysis assessed impact of baseline catastrophizing, RA, and their interaction, on the primary outcome of pain severity index, as well as secondary outcomes including cognitive and emotional impact of pain, and persistent opioid use.

RESULTS

We observed a significant interaction between the effect of catastrophizing and RA on PPMP. Specifically, RA was associated with reduced pain severity and pain impact 3, 6, and 12 months postoperatively, but only among those with high baseline catastrophizing scores. In addition, both RA and lower catastrophizing scores were associated with lower incidence of persistent opioid use.

CONCLUSIONS

The efficacy of therapies to prevent PPMP may be importantly influenced by pain-modulatory psychosocial characteristics. These findings underscore the importance of considering individual patient factors when applying preventive treatments, and of including their assessment in future trials.

Anatomical basis of fascial plane blocks

Fascial plane blocks (FPBs) are regional anesthesia techniques in which the space ("plane") between two discrete fascial layers is the target of needle insertion and injection. Analgesia is primarily achieved by local anesthetic spread to nerves traveling within this plane and adjacent tissues. This narrative review discusses key fundamental anatomical concepts relevant to FPBs, with a focus on blocks of the torso. Fascia, in this context, refers to any sheet of connective tissue that encloses or separates muscles and internal organs. The basic composition of fascia is a latticework of collagen fibers filled with a hydrated glycosaminoglycan matrix and infiltrated by adipocytes and fibroblasts; fluid can cross this by diffusion but not bulk flow. The plane between fascial layers is filled with a similar fat-glycosaminoglycan matric and provides gliding and cushioning between structures, as well as a pathway for nerves and vessels. The planes between the various muscle layers of the thorax, abdomen, and paraspinal area close to the thoracic paravertebral space and vertebral canal, are popular targets for ultrasound-guided local anesthetic injection. The pertinent musculofascial anatomy of these regions, together with the nerves involved in somatic and visceral innervation, are summarized. This knowledge will aid not only sonographic identification of landmarks and block performance, but also understanding of the potential pathways and barriers for spread of local anesthetic. It is also critical as the basis for further exploration and refinement of FPBs, with an emphasis on improving their clinical utility, efficacy, and safety.

Intercostal Nerve Block Using an Innovative Intraneedle Ultrasound Transducer: A Proof-of-Concept study

Intercostal nerve block is a widely used and effective approach to providing regional anesthesia in the thoracic region for pain relief. However, during ultrasound-guided intercostal nerve block, inaccurate identification of the anatomic structures or suboptimal positioning of the needle tip may result in complications and blockade failure. In this study, we designed an intraneedle ultrasound (INUS) system and validated its efficacy in identifying anatomic structures relevant to thoracic region anesthesia. The 20-MHz INUS transducer comprised a single lead magnesium niobate-lead titanate crystal, and gain was set to 20 dB. It fit into a regular 18G needle and emitted radiofrequency-mode ultrasound signals at 1 mm from the needle tip. One hundred intercostal punctures were performed in 10 piglets. Intercostal spaces were identified by surface ultrasound or palpation and located by inserting and advancing the INUS transducer needle until the appropriate anatomy was identified. Blockade success was defined by ideal saline and dye spreading and confirmed by dissection. The pleura had a distinctive ultrasound signal, and successful detection of the intercostal muscles, endothoracic fascia and double-layered parietal and visceral pleura was achieved in all 100 puncture attempts. INUS allows real-time identification of intercostal structures and facilitates successful intercostal nerve blocks.

Sympathetic Blockade for the Management of Refractory Ventricular Tachycardia: A Case Report

A 64-year-old man with a history of nonischemic cardiomyopathy (NICM) presented with electrical storm (ES). Episodes of ventricular tachycardia (VT) persisted despite endocardial catheter ablations and exhaustive pharmacotherapy. We used alternating regional anesthesia techniques, left stellate ganglion block, and proximal intercostal block to reduce sympathetic input to the heart, resulting in a significant decrease in VT burden. By using alternating catheter locations, we were able to maintain continuous sympathetic blockade for 31 days and bridge the patient to a successful orthotopic heart transplant.

Efficacy and safety of paravertebral block versus intercostal nerve block in thoracic surgery and breast surgery: A systematic review and meta-analysis

OBJECTIVE

To evaluate the analgesic efficacy and safety of paravertebral block (PVB) versus intercostal nerve block (INB) in thoracic surgery and breast surgery.

METHODS

The PubMed, Web of Science, Embase and the Cochrane Library were searched up to February 2020 for all available randomized controlled trials (RCTs) that evaluated the analgesic efficacy and safety of PVB compared with INB after thoracic surgery and breast surgery. For binary variables, odds ratio (OR) and 95% confidence interval (CI) was used. For continuous variables, weighted mean difference (WMD) and 95% confidence interval (CI) were used. RevMan5. 3 and Stata/MP 14.0 were used for performing the meta-analysis.

RESULTS

A total of 9 trials including 440 patients (PVB block:222 patients; INB: 218 patients) met the inclusion criteria. In the primary outcome, there was no significant differences between the two groups with respect to postoperative visual analogue scale (VAS) at 1h (Std. MD = -0. 20; 95% CI = -1. 11to 0. 71; P = 0. 66), 2h (Std. MD = -0. 71; 95% CI = -2. 32to 0. 91; P = 0. 39), 24h (Std. MD = -0. 36; 95% CI = -0. 73 to -0. 00; P = 0. 05) and 48h (Std. MD = -0. 04; 95% CI = -0. 20 to 0. 11; P = 0. 57). However, there was significant difference in VAS of non Chinese subgroup at 1h (Std. MD = 0. 33; 95% CI = 0. 25to 0. 41; P<0. 00001) and VAS of Chinese subgroup at 24h (Std. MD = -0.32; 95% CI = -0.49 to-0.14; P = 0.0003). In the secondary outcome, the analysis also showed no significant difference between the groups according to the rates of postoperative nausea and vomit (OR = 0. 63; 95% CI = 0. 38 to 1. 03; P = 0. 06) and the rates of postoperative additional analgesia (OR = 0. 57; 95% CI = 0. 21 to 1. 55; P = 0. 27). There was significant difference in postoperative consumption of morphine (Std. MD = -14. 57; 95% CI = -26. 63 to -0.25; P = 0. 02).

CONCLUSION

Compared with INB, PVB can provide better analgesia efficacy and cause lower consumption of morphine after thoracic surgery and breast surgery.