Phrenic nerve block caused by interscalene brachial plexus block: breathing effects of different sites of injection

Efficacy and safety of extrafascial injection versus intrafascial injection for interscalene brachial plexus block: a systematic review and meta-analysis

INTRODUCTION

This systematic review and meta-analysis aimed to assess the efficacy and safety of interscalene brachial plexus block (ISB) techniques in upper limb and shoulder surgeries.

EVIDENCE ACQUISITION

We conducted a comprehensive search of PubMed, Web of Science, Cochrane Central Register of Controlled Trials, Embase, Medline, and Scopus databases up to May 14th, 2023. We employed a search strategy involving keywords such as "brachial plexus block," "interscalene brachial plexus block," "ISB," "extrafascial," and "intrafascial," without applying search restrictions or filters. Eligible studies consisted of randomised controlled trials (RCTs) that compared extrafascial and intrafascial ISB techniques in adult patients undergoing upper limb and shoulder surgeries.

EVIDENCE SYNTHESIS

Our analysis included six RCTs encompassing 485 participants. Extrafascial injection demonstrated superiority over intrafascial injection in reducing the incidence of hemidiaphragmatic paresis (RR 0.33, 95% CI 0.124 to 0.47, P<0.00001) and preserving respiratory function (MS 0.31, 95% CI 0.1 to 0. 52, P=0.003 FEV1 in liters). Additionally, extrafascial ISB exhibited a lower risk of block-related complications (RR 0.35, 95% CI 0.25 to 0.50, P<0.00001). However, the intrafascial technique offered a faster sensory and motor block onset. The duration of sensory block did not significantly differ. The incidence of Horner syndrome showed no statistically significant difference.

CONCLUSIONS

Our findings favor extrafascial ISB techniques because they reduce hemidiaphragmatic paresis, preserve respiratory function, and lower block-related complications. However, further research is necessary to establish their safety and efficacy in specific patient populations.

A Case of Hospitalization After Pre-operative Interscalene Nerve Block in an Ambulatory Surgery Center

Interscalene nerve block (ISB) is an effective and low-risk local anesthetic (LA) procedure that is commonly employed for shoulder surgery. While phrenic nerve involvement occurs to some degree in every ISB procedure, the incidence of hypoxemia and other clinical signs of diaphragmatic disruption is much lower. This is a case of a 36-year-old female with no underlying respiratory disease who developed hypoxemia requiring a night of observation following an ISB for a rotator cuff repair procedure in an ambulatory surgical center. Her hypoxemia was easily treated with supplemental oxygen and she made a full recovery by the next day. The use of ultrasound guidance, reduced LA volume, less potent medication, sterile fluid for optimal visualization, and extrafascial administration should be considered for all patients receiving an ISB to prevent respiratory complications.

Advancing pain management for extremity trauma: the evolution of ultrasound-guided nerve blocks for patients in the supine position in trauma centers

PURPOSE

Trauma, particularly extremity trauma, poses a considerable challenge in healthcare, especially among young adults. Given the severity of patient pain and the risks associated with excessive opioid use, managing acute pain in trauma centers is inherently complex. This study aims to investigate the application and benefits of ultrasound-guided nerve blocks for early pain management in patients with extremity trauma positioned supine.

METHODS

A comprehensive literature review was conducted to assess the effectiveness and advantages of ultrasound-guided peripheral nerve blocks in the acute pain management of extremity trauma patients in the supine position. Special emphasis was placed on evaluating the selection criteria, indications, contraindications, adverse reactions, and potential complications associated with these nerve block techniques.

RESULTS

Ultrasound-guided nerve blocks represent a safer and more precise option for managing pain in extremity trauma patients placed in the supine position. These techniques offer significant advantages in terms of reducing healthcare expenses, diminishing reliance on opioid medications, and mitigating opioid-related complications. Nonetheless, challenges may arise due to the necessity for patient cooperation during specific nerve block procedures.

CONCLUSION

Ultrasound-guided nerve blocks present a promising avenue for early pain management in extremity trauma patients positioned supinely. Their implementation can lead to improved patient outcomes by alleviating pain severity, reducing opioid consumption, and cutting down healthcare costs. Further research and clinical integration of these techniques is imperative to enhance pain management protocols in trauma centers.

Superior Trunk Block Is an Effective Phrenic-Sparing Alternative to Interscalene Block for Shoulder Arthroscopy: A Systematic Review and Meta-Analysis

The interscalene block (ISB) is the standard regional anesthesia for shoulder arthroscopy. However, the superior trunk block (STB) is an alternative with a potentially safer profile. This meta-analysis aimed to compare the incidence and degree of hemidiaphragmatic paralysis and block efficacy of these techniques. We searched MEDLINE, EMBASE, Scopus, and Cochrane databases to identify randomized controlled trials (RCTs). The main outcome was total hemidiaphragmatic paralysis. We used the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) framework to assess the certainty of evidence. Four RCTs and 359 patients were included. The STB group showed lower total hemidiaphragmatic paralysis (RR 0.07; 95% CI 0.04 to 0.14; p<0.0001). The incidence of subjective dyspnea (p = 0.002) and Horner's syndrome (p<0.001) was significantly lower with STB relative to ISB. There was no significant difference between groups in block duration (p = 0.67). There was a high certainty of evidence in the main outcome as per the GRADE framework. Our findings suggest that STB has a better safety profile than ISB, resulting in lower rates of hemidiaphragmatic paralysis and dyspnea while providing a similar block. Therefore, STB could be preferred to ISB, especially in patients susceptible to phrenic nerve paralysis complications.

Peri-operative Hemi-diaphragmatic Variations After Brachial Plexus Block Above the Clavicle: A Prospective Observational Study of the Contralateral Side

OBJECTIVE

Hemi-diaphragm palsy after brachial plexus block above the clavicle (BPBAC) occurs frequently, but few patients develop post-operative pulmonary complications (PPC). We hypothesized that contralateral hemidiaphragm function increases after BPBAC. This contralateral function preserves global diaphragmatic function, avoiding PPC in the case of ipsilateral hemi-diaphragm palsy.

METHODS

This prospective observational cohort study included 64 adult patients undergoing shoulder surgery with planned BPBAC (interscalene brachial plexus block and supraclavicular block). The Thickening Fraction (TF) was measured by ultrasound in both hemi-diaphragms, ipsilateral (TF _ipsilateral) and contralateral (TF_{contralateral}) to the BPBAC, before and after the surgery. TF_global is the sum of TF_ipsilateral and TF_{contralateral}. PPC were defined as occurrences of dyspnea, tachypnea, SpO₂ <90% or SpO₂/FiO₂ <315.

RESULTS

TF_{contralateral} increased significantly (an average of 40%) after BPBAC (p = 0.001), and TF_ipsilateral decreased (an average of 72%). After BPBAC, 86% of patients had a decreased TF_ipsilateral and 59% of patients an increased TF_{contralateral} at post-operatively. Only 17% of patients have PPC.

CONCLUSION

After BPBAC, global diaphragm function decreases because of ipsilateral hemi-diaphragm reduction, but less than expected because of increased contralateral hemi-diaphragm function. As a part of diaphragm function, contralateral hemi-diaphragm function must be checked.

Low CERVICAL-2 plane block, a proposed regional anesthetic technique for acute cholecystitis

INTRODUCTION

Acute cholecystitis is a painful inflammatory disease of the gallbladder. The Low Cervical-2 Plane Block is a retrolaminar block that targets the C3, C4, and C5 spinal nerves, which provide sensory innervation to the gallbladder, in order to potentially provide analgesia to patients with pain associated with acute cholecystitis.

METHODS

In this brief report, a softly embalmed cadaver was injected with a dye mixture bilaterally.

RESULTS

Subsequent cadaveric dissection revealed spread of the injectate deep to the prevertebral fascia to the C4 lamina on the right side and the C5 lamina on the left side. Also, diffusion of the anesthetic over the ligamenta flava could spread inferiorly and laterally to the spinal nerve roots of C3-C5 and thus potentially target the direct sensory innervation of the gallbladder.

CONCLUSION

The Low Cervical-2 Plane Block is a potentially effective modality for treating intractable pain from acute cholecystitis. However, further cadaveric injections are needed to confirm the exact extent of spread of anesthetic. Clinical application of the Low Cervical-2 Plane Block in patients with acute cholecystitis is needed to establish the efficacy of this theoretical technique.

Ultrasound measurement of the distance of the phrenic nerve from the brachial plexus at the classic interscalene point and upper trunk: A volunteer-based observational study

Background and Aims

The method of blocking the brachial plexus at the level of the upper trunk has been gaining popularity as a phrenic nerve-sparing alternative for interscalene block. We aimed to measure the distance of the phrenic nerve from the upper trunk and compare it with the distance between the phrenic nerve and the brachial plexus at the classic interscalene point by using ultrasound.

Method

In this study, after ethical approval and trial registration, 100 brachial plexus of 50 volunteers were scanned from the emergence of the ventral rami and its course was traced to the supraclavicular fossa. The distance of the phrenic nerve from the brachial plexus was measured at two levels: the interscalene groove along the cricoid cartilage (classic interscalene block point) and from the upper trunk. The presence of anatomical variations of the brachial plexus, the classic traffic light sign, vessels across the plexus, and the location of the cervical oesophagus were also noted.

Results

At the classic interscalene point, the C5 ventral ramus was observed to be just emerging or to have fully emerged from the transverse process. The phrenic nerve was identified in 86/100 (86%) of scans. The median (IQR) distance of the phrenic nerve from the C5 ventral ramus was 1.6 (1.1-3.9) mm and that of the phrenic nerve from the upper trunk was 17 (12-20.5) mm. Anatomical variations of the brachial plexus, the classic traffic light sign, and vessels across the plexus were seen in 27/100, 53/100, and 41/100 scans respectively. The oesophagus was consistently located on the left side of the trachea.

Conclusions

There was a 10-fold increase in the distance of the phrenic nerve from the upper trunk when compared to that from the brachial plexus at the classic interscalene point.

The upper extremity regional anaesthesia trifecta: three upper extremity nerve blocks for awake upper-limb surgery in a patient with a history of contralateral pneumonectomy

While regional anaesthesia plays a pivotal role in the perioperative management of patients undergoing upper extremity surgery, its utility can be limited by the risk of hemi-diaphragmatic paresis. Furthermore, each approach to blocking the brachial plexus has associated limitations that may result in incomplete upper extremity anaesthesia. We describe the combination of three upper extremity nerve blocks to achieve surgical anaesthesia of the whole arm for a patient who had previously undergone a contralateral pneumonectomy. On this occasion, she required upper arm lipectomy and arteriovenous fistula formation. Adequate blockade was achieved with no significant perioperative complications. This case demonstrates the potential of this approach for patients with respiratory compromise undergoing upper limb procedures.

Regional Anesthetic and Analgesic Techniques for Clavicle Fractures and Clavicle Surgeries: Part 2-A Retrospective Study

Objective. Clavicle fracture fixation is commonly performed under general anesthesia due to the complex sensory innervation in this region which poses a challenge for anesthesiologists applying regional anesthetic (RA) techniques. In part 1 of this two-part study, we summarized the current literature describing various RA approaches in clavicle fractures and surgery. In our earlier scoping review, we surmised that a superficial or intermediate cervical plexus block (CPB) may provide analgesia for this procedure and, when combined with an interscalene brachial plexus block (ISB), can provide anesthesia to the clavicular region for surgical fixation. We performed a retrospective study, consolidating assumptions that were based on the results of our earlier scoping review. Methods. A retrospective study was conducted on 168 consecutive patients who underwent clavicle fixation surgery at a tertiary healthcare system in Singapore. We used a standardized pro forma to collate perioperative data from the electronic health records of both hospitals, including anesthetic technique, analgesic requirements, pain scores, and adverse events, up to the second postoperative day or up until discharge. Results. In our study, patients who received RA had significantly reduced pain scores and opioid requirements, compared to general anesthesia (GA) alone. Through subgroup analysis, differences were found in postoperative pain scores and opioid requirements in the following order: GA alone > GA with local infiltration analgesia > CPB > CPB plus ISB. All patients who received combined CPB and ISB had upper limb weakness in recovery, compared to none with CPB alone (p < 0.001). Of those who received an ISB either in isolation or combined with a CPB, four (9.3%) were reported to have dyspnea (within 24 h) and motor weakness that persisted beyond 12 h, compared to none for patients that received CPB alone. Conclusions. Addition of a CPB to GA for clavicle fracture fixation surgery is associated with reduced pain scores in the early postoperative period, with a lower opioid requirement compared to GA alone. In patients undergoing GA, the combination of a CPB with an ISB was associated with a small, although statistically significant, reduction in pain scores and opioid requirements compared to a CPB alone.

Suprascapular nerve block and axillary nerve block versus interscalene nerve block for arthroscopic shoulder surgery: A meta-analysis of randomized controlled trials

BACKGROUND

The interscalene brachial plexus block (ISB) is a commonly used nerve block technique for postoperative analgesia in patients undergoing shoulder arthroscopy surgery; however, it is associated with potentially serious complications. The use of suprascapular nerve block (SSNB) and axillary Nerve Block (ANB) has been reported as an alternative nerve block with fewer reported side effects for shoulder arthroscopy. This review aimed to compare the impact of SSNB and ANB with ISB during shoulder arthroscopy surgery.

METHODS

A meta-analysis was conducted to identify relevant randomized or quasirandomized controlled trials involving SSNB and ISB during shoulder arthroscopy surgery. We searched Web of Science, PubMed, Embase, Cochrane Controlled Trials Register, Cochrane Library, Highwire, CNKI, and Wanfang database from 2010 through August 2021.

RESULTS

We identified 641 patients assessed in 10 randomized or quasirandomized controlled trials. Compared with the ISB group, the SSNB+ANB group had higher visual analog scale or numerical rating scale in PACU (P = .03), 4 hour (P = .001),6 hour after the operation (P = .002), and lower incidence of complications such as Numb/Tingling (P = .001), Weakness (P <.00001), Horner syndrome (P = .001) and Subjective dyspnea (P = .002). No significant difference was found for visual analog scale or numerical rating scale 8 hour (P = .71),12 hour (P = .17), 16 hour (P = .38),1day after operation (P = .11), patient satisfaction (P = .38) and incidence of complications such as hoarseness (P = .07) and nausea/vomiting (P = .41) between 2 groups.

CONCLUSION

Our high-level evidence has established SSNB+ ANB as an effective and safe analgesic technique and a clinically attractive alternative to interscalene block during arthroscopic shoulder surgery, especially for severe chronic obstructive pulmonary disease, obstructive sleep apnea, and morbid obesity. Given our meta-analysis's relevant possible biases, we required more adequately powered and better-designed randomized controlled trial studies with long-term follow-up to reach a firmer conclusion.

Permeable spaces between glenohumeral ligaments as potential gateways for rapid regional anesthesia of the shoulder

Shoulder pain is a highly prevalent condition, often resulting in major life limitations, and requiring effective treatments. In this work, we explore the anatomical basis of a proposed approach to the regional anesthesia of the shoulder through a single injection under the subscapularis muscle. Bilateral experimental injections in shoulders from body donors (Radiolar ® and Methylene-Blue) under the subscapular muscle (n = 11) and cadaveric systematic dissections of other 35 shoulders from body donors were performed. Injectate spread was then qualitatively assessed. Long axis of permeable foramina in the anterior aspect of the shoulder joint capsule was measured in centimeters using a digital caliper. More than 40% of specimens had at least one permeable space (Weitbrech and/or Rouvière foramina) communicating the subscapular bursa and the articular space. We further demonstrate that an ultrasonography-guided injection under the subscapularis muscle allows the spread of the injectate through the anterior, inferior and posterodorsal walls of the articular capsule, the subacromial bursa, and the bicipital groove, as well as into the articular space for some injections. The odds of accidental intraarticular injection decrease when injecting with low volumes. This anatomical study provides a detailed description of foramina between glenohumeral ligaments. Furthermore, the data shown in this work supports, as a proof of concept, a safe alternative for rapid and specific blockade of terminal sensory branches innervating the shoulder joint capsule.

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians-part I: clinical indications

Point-of-care ultrasound (POCUS) is a critical skill for all regional anesthesiologists and pain physicians to help diagnose relevant complications related to routine practice and guide perioperative management. In an effort to inform the regional anesthesia and pain community as well as address a need for structured education and training, the American Society of Regional Anesthesia and Pain Medicine (ASRA) commissioned this narrative review to provide recommendations for POCUS. The guidelines were written by content and educational experts and approved by the Guidelines Committee and the Board of Directors of the ASRA. In part I of this two-part series, clinical indications for POCUS in the perioperative and chronic pain setting are described. The clinical review addresses airway ultrasound, lung ultrasound, gastric ultrasound, the focus assessment with sonography for trauma examination and focused cardiac ultrasound for the regional anesthesiologist and pain physician. It also provides foundational knowledge regarding ultrasound physics, discusses the impact of handheld devices and finally, offers insight into the role of POCUS in the pediatric population.

Suprascapular Nerve Block Is an Effective Pain Control Method in Patients Undergoing Arthroscopic Rotator Cuff Repair: A Randomized Controlled Trial

Background

Effective pain control in patients who have undergone arthroscopic rotator cuff surgery improves functional recovery and early mobilization. Interscalene blocks (ISBs), a widely used approach, are safe and provide fast pain relief; however, they are associated with complications. Another pain management strategy is the use of a suprascapular nerve block (SSNB).

Hypothesis

We hypothesized that indwelling SSNB catheters are a more effective pain control method than single-shot ISBs. We also hypothesized that indwelling SSNB catheters will reduce the level of rebound pain and the demand for opioid analgesics.

Study Design

Randomized controlled trial; Level of evidence, 1.

Methods

Included in this study were 93 patients who underwent arthroscopic rotator cuff surgery between May 2012 and January 2019. These patients were assigned to either the indwelling SSNB catheter group, the single-shot ISB group, or the control (sham/placebo) group (31 patients per group). Level of pain was measured with a visual analog scale (VAS; 0 to 10 [worst pain]) on the day of the operation. The preoperative VAS score was recorded at 6 AM on the day of operation, and the postoperative scores were recorded at 1, 8, and 16 hours after surgery and then every 8 hours until postoperative day 3.

Results

The VAS pain scores were lower in the SSNB and ISB groups than in the control group up to postoperative hour (POH) 8, with the most significant difference at POH 8. At POH 1 and POH 8, the mean VAS scores for each group were 2.29 and 1.74 (SSNB), 2.59 and 2.50 (ISB), and 3.42 and 4.48 (control), respectively. VAS scores in the SSNB and ISB groups were consistently <3, compared with a mean VAS score of 3.1 ± 1.58 in the control group (P < .001). Compared with the ISB group, the SSNB group had significantly fewer side effects such as rebound pain duration as well as lower VAS scores (P < .001).

Conclusion

VAS scores were the lowest in the indwelling SSNB catheter group, with the most pronounced between-group difference in VAS scores at POH 8. Severity and recurring frequency of pain were lower in the indwelling SSNB catheter group than in the single-shot ISB group.

Analgesic efficacy of ultrasound-guided interscalene block vs. supraclavicular block for ambulatory arthroscopic rotator cuff repair: A randomised noninferiority study

BACKGROUND

Ultrasound-guided interscalene block (ISB) is the reference technique for pain control after ambulatory upper limb surgery, but supraclavicular block (SCB) is an alternative.

OBJECTIVES

The aim of this study was to compare the efficacy of SCB vs. ISB in patients undergoing ambulatory arthroscopic rotator cuff repair (ARCR), with the hypothesis of noninferiority of SCB analgesia compared with ISB.

DESIGN

A randomised, single-blind, noninferiority study.

SETTING

Hôpital Privé Jean Mermoz, Centre Paul Santy, Lyon, France.

PATIENTS

Ambulatory ARCR patients.

INTERVENTION

Patients were randomly allocated (1 : 1) to receive a single injection SCB or ISB, as well as general anaesthesia. All patients received a postoperative analgesic prescription for home use before leaving hospital (including fast-acting oral morphine sulphate). Patients completed a telephone questionnaire on days 1 and 2 postsurgery.

MAIN OUTCOME MEASURES

Primary endpoint was oral morphine consumption (mg) during the first 2 days postsurgery. If the difference between mean morphine consumption in the SCB vs. ISB group was less than 30 mg, noninferiority of SCB compared with ISB would be demonstrated. Secondary evaluation criteria included pain scores (numerical rating scale), duration of motor and sensory blockade, and satisfaction with treatment.

RESULTS

The per-protocol cohort included 103 patients (SCB = 52, ISB = 51) (57% men, median age 58 years). Mean morphine consumption in the 48 h postsurgery was 9.4 vs. 14.7 mg in the SCB and ISB groups, respectively (difference −5.3, P < 0.001). The upper limit of the 95% CI was less than 30 mg, demonstrating noninferiority of SCB compared with ISB. No difference was observed between the two groups in terms of pain scores or the duration of motor or sensory blockade. Overall, 98% of patients in the SCB group vs. 90% in the ISB group were satisfied with their treatment.

CONCLUSION

SCB is as effective as ISB in terms of postoperative analgesia based on oral morphine consumption in patients undergoing ambulatory ARCR.

TRIAL REGISTRATION

EudraCT number: 2016-A00747-47.

Novel Regional Anesthesia for Outpatient Surgery

PURPOSE OF REVIEW

Peripheral nerve blocks are effective and safe modalities for perioperative analgesia. But it remains unclear what blocks are adequate for ambulatory surgeries, as well as the proper patient management before and after discharge.

RECENT FINDINGS

Emerging nerve blocks have sparked interests due to ease to perform under ultrasound guidance and lower risks of adverse events. Some of these novel blocks are particularly suitable for ambulatory procedures, including but not limited to motor-sparing lower extremity nerve blocks and phrenic-sparing nerve blocks for shoulder surgeries. The adoption of peripheral nerve block into outpatient surgery is a multidisciplinary effort that encompasses appropriate patient choice, careful selection of nerve blocks that minimize potential adverse events after discharge, and proper patient follow-up until block effects resolve.

Regional Nerve Blocks-Best Practice Strategies for Reduction in Complications and Comprehensive Review

PURPOSE OF REVIEW

Understanding the etiologies of the complications associated with regional anesthesia and implementing methods to reduce their occurrence provides an opportunity to foster safer practices in the delivery of regional anesthesia.

RECENT FINDINGS

Neurologic injuries following peripheral nerve block (PNB) and neuraxial blocks are rare, with most being transient. However, long-lasting and devastating sequelae can occur with regional anesthesia. Risk factors for neurologic injury following PNB include type of block, injection in the presence of deep sedation or general anesthesia, presence of existing neuropathy, mechanical trauma from the needle, pressure injury, intraneural injection, neuronal ischemia, iatrogenic injury related to surgery, and local anesthetic neurotoxicity. The present investigation discusses regional blocks, complications of regional blocks, risk factors, site-specific limitations, specific complications and how to prevent them from happening, avoiding complications in regional anesthesia, and the future of regional anesthesia.

Ultrasonography-guided anterior approach for axillary nerve blockade: An anatomical study

Combined ultrasound (US)-guided blockade of the suprascapular and axillary nerves (ANs) has been proposed as an alternative to interscalene blockade for pain control in shoulder joint pathology or postsurgical care. This technique could help avoid respiratory complications and/or almost total upper limb palsy. Nowadays, the AN blockade is mostly performed using an in-plane caudal-to-cephalic approach from the posterior surface of the shoulder, reaching the nerve immediately after it exits the neurovascular quadrangular space (part of the spatium axillare). Despite precluding most respiratory complications, this approach has not made postsurgical pain relief any better than an interscalene blockade, probably because articular branches of the AN are not blocked.Cephalic-to-caudal methylene blue injections were placed in the first segment of the AN of six Thiel-embalmed cadavers using an US-guided anterior approach in order to compare the distribution with that produced by a posterior approach to the contralateral AN in the same cadaver. Another 21 formalin-fixed cadavers were bilaterally dissected to identify the articular branches of the AN.We found a good spread of the dye on the AN and a constant relationship of this nerve with the subscapularis muscle. The dye reached the musculocutaneous nerve, which also contributes to shoulder joint innervation. We describe the anatomical landmarks for an ultrasonography-guided anterior AN blockade and hypothesize that this anterior approach will provide better pain control than the posterior approach owing to complete blocking of the joint nerve. Clin. Anat. 33:488-499, 2020. © 2019 Wiley Periodicals, Inc.

Pain Management in the Emergency Department: a Review Article on Options and Methods

CONTEXT

The aim of this review is to recognizing different methods of analgesia for emergency medicine physicians (EMPs) allows them to have various pain relief methods to reduce pain and to be able to use it according to the patient's condition and to improve the quality of their services.

EVIDENCE ACQUISITION

In this review article, the search engines and scientific databases of Google Scholar, Science Direct, PubMed, Medline, Scopus, and Cochrane for emergency pain management methods were reviewed. Among the findings, high quality articles were eventually selected from 2000 to 2018, and after reviewing them, we have conducted a comprehensive comparison of the usual methods of pain control in the emergency department (ED).

RESULTS

For better understanding, the results are reported in to separate subheadings including "Parenteral agents" and "Regional blocks". Non-opioids analgesics such as nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen are commonly used in the treatment of acute pain. However, the relief of acute moderate to severe pain usually requires opioid agents. Considering the side effects of systemic drugs and the restrictions on the use of analgesics, especially opioids, regional blocks of pain as part of a multimodal analgesic strategy can be helpful.

CONCLUSION

This study was designed to investigate and identify the disadvantages and advantages of using each drug to be able to make the right choices in different clinical situations for patients while paying attention to the limitations of the use of these analgesic drugs.

Diaphragmatic thickness ratio (inspiratory/expiratory) as a diagnostic method of diaphragmatic palsy associated with interescalene block

INTRODUCTION

Diaphragmatic paralysis is a side-effect associated with interscalene block. Thickness index of the diaphragm muscle (inspiratory thickness/expiratory thickness) obtained by ultrasound has recently been introduced in clinical practice for diagnosis of diaphragm muscle atrophy. Our objective was to evaluate this index for the diagnosis of acute phrenic paresis associated with interscalene block.

PATIENTS AND METHODS

We designed an observational study in 22 patients scheduled for shoulder arthroscopy. Spirometry was performed (criteria of phrenic paresis was a decrease in FVC and FEV1 ≥20%). Ultrasound apposition zone was assessed in anterior axillary line and diaphragmatic displacement was evaluated on inspiration and expiration (number of intercostal spaces; phrenic paresis considered a reduction ≥25%) and thickness of the diaphragm muscle (a phrenic paresis was considered an index <1.2). These determinations were performed before and at 20min after interscalene block at C5-C6 with 20ml of 0.5% ropivacaine.

RESULTS

Twenty-one patients (95%) presented phrenic nerve block according to one or more of the methods used. One patient did not show any symptoms or signs suggestive of phrenic paralysis and was excluded. All the patients presented phrenic paresis based on the diaphragmatic thickness index, with the pre-block index being 1.8±0.5 and post-block of 1.05±0.06 (P<0.001). Ninety percent of the patients (19) presented phrenic paresis according to spirometry and all the patients had a reduction in diaphragmatic movement after the block (from 1.9±0.5 intercostal spaces to 0.5±0.3; P<0.001).

CONCLUSION

The index of inspiratory / expiratory diaphragmatic thickness at cut-off <1.2 seems to be useful in the diagnosis of phrenic paresis associated with interscalene block. This index does not require a baseline pre-assessment.

Review of the evidence: best analgesic regimen for shoulder surgery

Multimodal pain management has been advocated in patients experiencing acute pain after surgical procedures due to tissue damage and the subsequent inflammatory response. For patients undergoing shoulder surgeries, studies have definitively shown that interscalene blocks (ISBs) via single-injection or continuous infusion can reduce the total opioid consumption and can lower pain scores after surgery. In some cases, ISBs can be used as the sole anesthetic during shoulder surgeries and spare patients of receiving general anesthesia. However, clinicians should be fully aware of potential pulmonary complications of ISBs and weigh the risk-benefit ratio in patients with limited pulmonary reserve.