Perioperative pain management for cleft palate surgery: a systematic review and procedure-specific postoperative pain management (PROSPECT) recommendations.

BACKGROUND/IMPORTANCE: Cleft palate surgery is associated with significant postoperative pain. Effective pain control can decrease stress and agitation in children undergoing cleft palate surgery and improve surgical outcomes. However, limited evidence often results in inadequate pain control after cleft palate surgery. OBJECTIVES: The aim of this review was to evaluate the available evidence and to develop recommendations for optimal pain management after cleft palate surgery using procedure-specific postoperative pain management (PROSPECT) methodology. EVIDENCE REVIEW: MEDLINE, Embase, and Cochrane Databases were searched for randomized controlled trials and systematic reviews assessing pain in children undergoing cleft palate repair published in English language from July 2002, through August 2023. FINDINGS: Of 1048 identified studies, 19 randomized controlled trials and 4 systematic reviews met the inclusion criteria. Interventions that improved postoperative pain, and are recommended, include suprazygomatic maxillary nerve block or palatal nerve block (if maxillary nerve block cannot be performed). Addition of dexmedetomidine to local anesthetic for suprazygomatic maxillary nerve block or, alternatively, as intravenous administration perioperatively is recommended. These interventions should be combined with a basic analgesic regimen including acetaminophen and nonsteroidal anti-inflammatory drugs. Of note, pre-incisional local anesthetic infiltration and dexamethasone were administered as a routine in several studies, however, because of limited procedure-specific evidence their contribution to pain relief after cleft palate surgery remains unknown. CONCLUSION: The present review identified an evidence-based analgesic regimen for cleft palate surgery in pediatric patients. PROSPERO REGISTRATION NUMBER: CRD42022364788.

Pain management after elective craniotomy: A systematic review with procedure-specific postoperative pain management (PROSPECT) recommendations.

BACKGROUND: Pain after craniotomy can be intense and its management is often suboptimal. OBJECTIVES: We aimed to evaluate the available literature and develop recommendations for optimal pain management after craniotomy. DESIGN: A systematic review using procedure-specific postoperative pain management (PROSPECT) methodology was undertaken. DATA SOURCES: Randomised controlled trials and systematic reviews published in English from 1 January 2010 to 30 June 2021 assessing pain after craniotomy using analgesic, anaesthetic or surgical interventions were identified from MEDLINE, Embase and Cochrane Databases. ELIGIBILITY CRITERIA: Each randomised controlled trial (RCT) and systematic review was critically evaluated and included only if met the PROSPECT requirements. Included studies were evaluated for clinically relevant differences in pain scores, use of nonopioid analgesics, such as paracetamol and NSAIDs, and current clinical relevance. RESULTS: Out of 126 eligible studies identified, 53 RCTs and seven systematic review or meta-analyses met the inclusion criteria. Pre-operative and intra-operative interventions that improved postoperative pain were paracetamol, NSAIDs, intravenous dexmedetomidine infusion, regional analgesia techniques, including incision-site infiltration, scalp nerve block and acupuncture. Limited evidence was found for flupirtine, intra-operative magnesium sulphate infusion, intra-operative lidocaine infusion, infiltration adjuvants (hyaluronidase, dexamethasone and α-adrenergic agonist added to local anaesthetic solution). No evidence was found for metamizole, postoperative subcutaneous sumatriptan, pre-operative oral vitamin D, bilateral maxillary block or superficial cervical plexus block. CONCLUSIONS: The analgesic regimen for craniotomy should include paracetamol, NSAIDs, intravenous dexmedetomidine infusion and a regional analgesic technique (either incision-site infiltration or scalp nerve block), with opioids as rescue analgesics. Further RCTs are required to confirm the influence of the recommended analgesic regimen on postoperative pain relief.

Pain management after laminectomy: a systematic review and procedure-specific post-operative pain management (prospect) recommendations.

PURPOSE: With lumbar laminectomy increasingly being performed on an outpatient basis, optimal pain management is critical to avoid post-operative delay in discharge and readmission. The aim of this review was to evaluate the available literature and develop recommendations for optimal pain management after one- or two-level lumbar laminectomy. METHODS: A systematic review utilizing the PROcedure-SPECific Post-operative Pain ManagemenT (PROSPECT) methodology was undertaken. Randomised controlled trials (RCTs) published in the English language from 1 January 2008 until 31 March 2020-assessing post-operative pain using analgesic, anaesthetic and surgical interventions-were identified from MEDLINE, EMBASE and Cochrane Databases. RESULTS: Out of 65 eligible studies identified, 39 RCTs met the inclusion criteria. The analgesic regimen for lumbar laminectomy should include paracetamol and a non-steroidal anti-inflammatory drug (NSAID) or cyclooxygenase (COX)-2 selective inhibitor administered preoperatively or intraoperatively and continued post-operatively, with post-operative opioids for rescue analgesia. In addition, surgical wound instillation or infiltration with local anaesthetics prior to wound closure is recommended. Some interventions-gabapentinoids and intrathecal opioid administration-although effective, carry significant risks and consequently were omitted from the recommendations. Other interventions were also not recommended because there was insufficient, inconsistent or lack of evidence. CONCLUSION: Perioperative pain management for lumbar laminectomy should include paracetamol and NSAID- or COX-2-specific inhibitor, continued into the post-operative period, as well as intraoperative surgical wound instillation or infiltration. Opioids should be used as rescue medication post-operatively. Future studies are necessary to evaluate the efficacy of our recommendations.

Ultrasonographic needle tip tracking for in-plane infraclavicular brachialis plexus blocks: a randomized controlled volunteer study.

BACKGROUND: Onvision is a new technology for needle tip detection and tracking in ultrasound-guided regional anesthesia. The system consists of a piezoelectric sensor close to the needle tip and an electronic console integrated in the ultrasound system. The needle tip is visualized by a green circle on the ultrasound screen. The aim of the study was to investigate the effect of the new needle tip tracking technology on in-plane infraclavicular plexus blocks. METHODS: The study was a randomized, controlled, observer blinded cross-over trial in 26 healthy volunteers. Two specialists in anesthesiology performed an ultrasound-guided infraclavicular lateral sagittal brachial plexus block with and without needle tip tracking. Primary outcome was procedure time, measured from insertion of the needle until local anesthesia injection was completed. Secondary outcome measures included the number of hand movements and path lengths (assessed by hand motion analysis), block success rate, onset time and duration, discomfort experienced by the volunteers, and the anesthesiologists' confidence as to whether their block would be successful or not. RESULTS: Mean (SD) procedure time was 183.0 (56.1) s with and 206.8 (56.2) s without needle tip tracking (p=0.16). There were no significant differences in any of the secondary outcomes. Two volunteers' experienced Horner syndrome after blocks without needle tip tracking. No other adverse events occurred during the study. CONCLUSION: Our study on needle tip tracking for infraclavicular blocks did not reveal any significant differences between active needle tip tracking and the control procedures, neither for primary outcome nor secondary outcome measurements. TRIAL REGISTRATION NUMBER: NCT03631914.

A Swiss nationwide survey shows that dual guidance is the preferred approach for peripheral nerve blocks.

Ultrasound has significantly increased safety and effectiveness in regional anesthesia. However, little is known about its clinical use. We studied clinical approaches currently used by anesthesiologists, conducted a nationwide survey, and analyzed data collected in ordered logistic regression models. All active members of the Swiss Society for Anaesthesiology and Resuscitation (SSAR/SGAR) were asked to participate. Reported practice in nerve localization, safety, and techniques used for peripheral nerve blocks (PNB) were main outcome measures. Experience ranged from 3 to >30 years. The mean number of block techniques mastered was 11.5 ± 5.9. Standard monitoring was regularly used, whereas sterile coats were less frequently used by anesthesiologists who self-estimated a higher level of expertise in PNB (ordered logit coefficient -0.05, 95% CI -0.07 to -0.02, P < 0.001; pseudo r2 = 0.019; probability > Chi2 = 0.02). The more self-estimated expertise anesthesiologists had, the less likely they were to use nerve stimulation in combination with ultrasound (dual guidance) (ordered logit coefficient -0.31; 95% CI -0.85 to -0.03: P = 0.03; pseudo r2 = 0.007; probability > Chi2 = 0.05). The high share of reported standard monitoring meets the recommendations of the Helsinki Patient Safety Declaration. Dual guidance appears to be the preferred approach for safely localizing nerves for PNB in Switzerland.

The Analgesic Effect of Ultrasound-Guided Quadratus Lumborum Block After Cesarean Delivery: A Randomized Clinical Trial.

BACKGROUND: Landmark and ultrasound-guided transversus abdominis plane blocks have demonstrated an opioid-sparing effect postoperatively after cesarean delivery. The more posterior quadratus lumborum (QL) might provide superior local anesthetic spread to the thoracolumbar fascia and paravertebral space. The aim of our study was to evaluate the efficacy of the QL block after cesarean delivery. METHODS: A randomized, double-blind, controlled trial was performed. Forty parturients undergoing cesarean delivery received bilateral ultrasound-guided QL blocks with either 2 mg/mL ropivacaine or saline postoperatively. All patients received spinal anesthesia with bupivacaine and sufentanil and a postoperative analgesic regimen of paracetamol, ibuprofen, and ketobemidone administered by a patient-controlled analgesic pump. The ketobemidone consumption and time of each dose administered were recorded. The primary outcome was ketobemidone consumption during the first 24 hours postoperatively. Secondary and exploratory analyses compared repeated measures of pain scores, nausea, and fatigue, and total differences in time until patients were able to stand and able to walk 5 m, and the interaction between the effective analgesic score and time. RESULTS: All 40 patients completed the trial, 20 in each group. The cumulative ketobemidone consumption in 24 hours was reduced in the active group compared with the control group (P = .04; ratio of means = 0.60; 95% confidence interval, 0.37-0.97). The effective analgesic scores were significantly better in the treatment group compared with the placebo group both at rest (P < .01) and during coughing (P < .01). CONCLUSIONS: QL block with ropivacaine reduces the postoperative ketobemidone consumption and pain intensity as a part of a multimodal analgesic regimen that excludes neuraxial morphine.

Detection of needle to nerve contact based on electric bioimpedance and machine learning methods.

In an ongoing project for electrical impedance-based needle guidance we have previously showed in an animal model that intraneural needle positions can be detected with bioimpedance measurement. To enhance the power of this method we in this study have investigated whether an early detection of the needle only touching the nerve also is feasible. Measurement of complex impedance during needle to nerve contact was compared with needle positions in surrounding tissues in a volunteer study on 32 subjects. Classification analysis using Support-Vector Machines demonstrated that discrimination is possible, but that the sensitivity and specificity for the nerve touch algorithm not is at the same level of performance as for intra-neuralintraneural detection.

The relationship of the musculocutaneous nerve to the brachial plexus evaluated by MRI.

Axillary plexus blocks (AXB) are widely used for upper limb operations. It is recommend that AXB should be performed using a multiple injection technique. Information about the course and position of the musculocutaneous nerve (MCN) is of relevance for AXB performance. The objective of this study was to examine the position of the MCN and its relationship to the axillary sheath using MRI. 54 patients underwent an AXB with 40 ml of local anaesthetic before MRI examination. The course of the MCN and the position where it left the axillary sheath and perforated the coracobrachial muscle (MCN exit point), in relation to the axillary artery and the block needle insertion point in the axillary fold, were recorded. The MCN was seen clearly in 23, partly in 26, and not identified in five patients at the MCN exit point. The mean distance from the insertion point of the block needle in the axillary fold to the MCN exit point was 36.8 mm (SD = 18.9, range: 0-90.5). In 37 patients the MCN exit point was positioned inside the Q1 quadrant (lateral anterior to the axillary artery) and in 11 patients inside the Q2 quadrant (medial anterior to the axillary artery). There is a wide variability as to where the musculocutaneous nerve (MCN) leaves the axillary sheath. Therefore multiple injection techniques, or the use of a proximally directed catheter, should be appropriate to block the MCN.

Detection of intraneural needle-placement with multiple frequency bioimpedance monitoring: a novel method.

Electrical impedance measurements have been used to detect intraneural needle placement, but there is still a lack of precision with this method. The purpose of the study was to develop a method for the discrimination of nerve tissue from other tissue types based on multiple frequency impedance measurements. Impedance measurements with 25 different frequencies between 1.26 and 398 kHz were obtained in eight pigs while placing the tip of a stimulation needle within the sciatic nerve and in other tissues. Various impedance variables and measurement frequencies were tested for tissue discrimination. Best tissue discrimination was obtained by using three different impedance parameters with optimal measurement frequencies: Modulus (126 kHz), Phase angle (40 kHz) and the Delta of the phase angle (between 126 and 158 kHz). These variables were combined in a Compound variable C. The area under the curve in a receiver operating characteristic was consecutively increased for the Modulus (78 %), Phase angle (86 %), Delta of the phase angle (94 %), and the Compound variable C (97 %), indicating highest specificity and sensitivity for C. An algorithm based on C was implemented in a real-time feasibility test and used in an additional test animal to demonstrate our new method. Discrimination between nerve tissue and other tissue types was improved by combining several impedance variables at multiple measurement frequencies.

The Shamrock lumbar plexus block: A dose-finding study.

BACKGROUND: The Shamrock technique is a new method for ultrasound-guided lumbar plexus blockade. Data on the optimal local anaesthetic dose are not available. OBJECTIVE: The objective of this study is to estimate the effective dose of ropivacaine 0.5% for a Shamrock lumbar plexus block. DESIGN: A prospective dose-finding study using Dixon's up-and-down sequential method. SETTING: University Hospital Orthopaedic Anaesthesia Unit. INTERVENTION: Shamrock lumbar plexus block performance and block assessment were scheduled preoperatively. Ropivacaine 0.5% was titrated with the Dixon and Massey up-and-down method using a stepwise change of 5 ml in each consecutive patient. Combined blocks of the femoral, the lateral femoral cutaneous and the obturator nerve were prerequisite for a successful lumbar plexus block. PATIENTS: Thirty patients scheduled for lower limb orthopaedic surgery completed the study. MAIN OUTCOME MEASURES: The minimum effective anaesthetic volume of ropivacaine 0.5% (ED50) to achieve a successful Shamrock lumbar plexus block in 50% of the patients. Further analysis of the data was performed with a logistic regression model to calculate ED95 and to estimate the effective doses for a sensory lumbar plexus block not requiring a motor block of the femoral nerve. RESULTS: The Dixon and Massay estimate of the ED50 was 20.4 [95% confidence interval (95% CI) 13.9 to 30.0] ml ropivacaine 0.5%. The logistic regression estimate of the ED95 was 36.0 (95% CI 19.7 to 52.2) ml ropivacaine 0.5%. For a sensory lumbar plexus block, the ED50 was 17.1 (95% CI 12.3 to 21.9) ml and the ED95 was 25.8 (95% CI 18.6 to 33.1) ml. CONCLUSION: A volume of 20.4 ml ropivacaine 0.5% provided a successful Shamrock lumbar plexus block in 50% of the patients. A volume of 36.0 ml would be successful in 95% of the patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01956617.

Brachial plexus block with or without ultrasound guidance.

PURPOSE OF REVIEW: Should ultrasound or nerve stimulation be used for brachial plexus blocks? We investigated last year's literature to help answer this question. RECENT FINDINGS: Many of the reports concluded that ultrasound guidance may provide a higher success rate for brachial plexus blocks than guidance by nerve stimulator. However, the studies were not large enough to conclude that ultrasound will reduce the risk of nerve injury, local anesthetic toxicity or pneumothorax. Ultrasound may reveal anatomical variations of importance for performing brachial plexus blocks. For postoperative analgesia, 5 ml of ropivacaine 0.5% has been sufficient for an ultrasound-guided interscalene block. For peroperative anesthesia, as much as 42 ml of a local anesthetic mixture was calculated to be appropriate for an ultrasound-guided supraclavicular method. For the future, we notice that three-dimensional and four-dimensional ultrasound technology may facilitate visualizing the needle, the nerves and the local anesthetic distribution. Impedance measurements may be helpful for nerve blocks not guided by ultrasound. SUMMARY: We think that the literature gives a sufficient basis to recommend the use of ultrasound for guidance of brachial plexus blocks. The potential for ultrasound to improve efficacy and reduce complications of brachial plexus blocks requires larger scaled studies.

Current threshold for nerve stimulation depends on electrical impedance of the tissue: a study of ultrasound-guided electrical nerve stimulation of the median nerve.

BACKGROUND: Understanding the mechanisms causing variation in current thresholds for electrical nerve stimulation may improve the safety and success rate of peripheral nerve blocks. Electrical impedance of the tissue surrounding a nerve may affect the response to nerve stimulation. In this volunteer study, we investigated the relationship between impedance and current threshold needed to obtain a neuromuscular response. METHODS: Electrical nerve stimulation and impedance measurements were performed for the median nerve in the axilla and at the elbow in 29 volunteers. The needletip was positioned at a distance of 5, 2.5, and 0 mm from the nerve as judged by ultrasound. Impulse widths of 0.1 and 0.3 ms were used for nerve stimulation. RESULTS: A significant inverse relationship between impedance and current threshold was found at the elbow, at nerve-to-needle distances of 5 and 2.5 mm (P = 0.001 and P = 0.036). Impedance values were significantly lower in the axilla (mean 21.1, sd 9.7 kohm) than at the elbow (mean 36.6, sd 13.4 kohm) (P < 0.001). Conversely, current thresholds for nerve stimulation were significantly higher in the axilla than at the elbow (P < 0.001, P < 0.001, P = 0.024). A mean ratio of 1.82 was found for the measurements of current thresholds with 0.1 versus 0.3 ms impulse duration. CONCLUSIONS: Our results demonstrate an inverse relationship between impedance measurements and current thresholds and suggest that current settings used for nerve stimulation may require adjustment based on the tissue type. Further studies should be performed to investigate the clinical impact of our findings.

Electrical nerve stimulation or ultrasound guidance for lateral sagittal infraclavicular blocks: a randomized, controlled, observer-blinded, comparative study.

BACKGROUND: Ultrasound guidance is frequently used to perform infraclavicular brachial plexus blocks. In this study, we compared electrical nerve stimulation and ultrasound guidance for the lateral sagittal infraclavicular block. METHODS: Eighty patients, ASA 1-2, were randomized for either nerve stimulation (group NS) or ultrasound-guided blocks (group US). The brachial plexus was anesthetized with 0.6 mL/kg mepivacaine (15 mg/mL) with epinephrine (2.5 microg/mL) in both groups. For ultrasound-guided blocks, local anesthetic was injected cranioposterior to the axillary artery. An observer who was blinded for the method assessed the blocks and questioned the patients. Successful block was defined as analgesia or anesthesia of all five nerves distal to the elbow. The main outcome variables were the time until readiness for surgery, quantified discomfort during the block, and pain related to tourniquet ischemia on a numeric rating scale (0-10). RESULTS: Block performance time was 4.3 min (sd 1.3) and 4.1 min (sd 1.3) (P = 0.64) in group NS and group US, respectively. Onset time for sensory block was 13.7 min (sd 6.6) and 13.9 min (sd 5.8), (P = 0.99). The time until readiness for surgery was 18.1 min in both groups (sd 6.6 and 6.0) (P = 0.99). Median discomfort related to the block procedure was 1 in both groups (P = 0.92), and median tourniquet pain was 0.5 in group NS and 1 in group US (P = 32). Differences in success rates, between 85% in group NS and 95% in group US, were not significant (P = 0.26). CONCLUSIONS: We conclude that favorable results can be obtained when either nerve stimulation or ultrasound guidance is used for lateral sagittal infraclavicular block. Using ultrasound, local anesthetic injection cranioposterior to the artery appears feasible.

Use of magnetic resonance imaging to define the anatomical location closest to all three cords of the infraclavicular brachial plexus.

Infraclavicular techniques are often used to perform brachial plexus blocks. In our volunteer study we used magnetic resonance imaging to identify the brachial plexus and axillary vessels in a sagittal plane corresponding to the lateral sagittal infraclavicular block. In 20 volunteers, all cords were positioned within 2 cm from the artery approximately within 2/3 of a circle. We derived an injection site that was closest to all cords, cranio-posterior and adjacent to the axillary artery. We conclude that this knowledge may be useful for the performance of infraclavicular blocks aided by ultrasound. However, our proposals should be tested by clinical studies.