ED90 of spinal 2-chloroprocaine 1% in ambulatory knee arthroscopy up to 45 min: a randomized biased-coin- up-and-down sequential allocation trial

BackgroundA short acting spinal anesthetic facilitates smooth flow since quick recovery of motor function will facilitate unassisted ambulation. The aim of this study was to estimate the effective dose (ED90) of intrathecal 2-chloroprocaine 1% in outpatient knee arthroscopy.MethodsTwo cohorts were included in two different hospitals. In cohort I, a randomized biased-coin up-and-down design with 40 patients was used to find the ED90. Four dose-levels of plain 2-chloroprocaine 1% were used: 25, 30, 35 and 40 mg. The identified primary outcome, the ED90, was validated in 50 patients in cohort II with an open label design. Secondary outcomes included time to complete recovery from motor and sensory block with spinal injection as time zero, peak sensory block level, urine retention and time until hospital discharge.ResultsForty patients were included in the final analysis in cohort I. The ED90 was estimated at 27.8 mg, successful spinal anesthesia was obtained in 38 patients (95%). Fifty patients were included in the final analysis in cohort II, 49 patients had successful anesthesia with a fixed round dose of 28 mg. In this Cohort, peak sensory block was T10/T11 (range: (L4–T4)). The median time to full recovery of the motor block was 60 min (45–60) and 90 min (75–105) for the sensory block. The mean time to hospital discharge was 2.9 hours (0.7).ConclusionThe ED90 of 2-chloroprocaine 1% in knee arthroscopy was estimated to be 27.8 mg. In an external population, the ED90 resulted in successful anesthesia in 98% of the patients (95% CI 89% to 100%).Trial registration numberNetherlands Trial Registry (NL6769).

Quality of meta-analyses of non-opioid, pharmacological, perioperative interventions for chronic postsurgical pain: a systematic review

BackgroundIn an attempt to aggregate observations from clinical trials, several meta-analyses have been published examining the effectiveness of systemic, non-opioid, pharmacological interventions to reduce the incidence of chronic postsurgical pain.ObjectiveTo inform the design and reporting of future studies, the purpose of our study was to examine the quality of these meta-analyses.Evidence reviewWe conducted an electronic literature search in Embase, MEDLINE, and the Cochrane Database of Systematic Reviews. Published meta-analyses, from the years 2010 to 2020, examining the effect of perioperative, systemic, non-opioid pharmacological treatments on the incidence of chronic postsurgical pain in adult patients were identified. Data extraction focused on methodological details. Meta-analysis quality was assessed using the A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) critical appraisal tool.FindingsOur search yielded 17 published studies conducting 58 meta-analyses for gabapentinoids (gabapentin and pregabalin), ketamine, lidocaine, non-steroidal anti-inflammatory drugs, and mexiletine. According to AMSTAR 2, 88.2% of studies (or 15/17) were low or critically low in quality. The most common critical element missing was an analysis of publication bias. Trends indicated an improvement in quality over time and association with journal impact factor.ConclusionsWith few individual trials adequately powered to detect treatment effects, meta-analyses play a crucial role in informing the perioperative management of chronic postsurgical pain. In light of this inherent value and despite a number of attempts, high-quality meta-analyses are still needed.PROSPERO registration numberCRD42021230941.

Effect of superior trunk block on diaphragm function and respiratory parameters after shoulder surgery

BackgroundThe interscalene brachial plexus block has been used effectively for intraoperative and postoperative analgesia in patients undergoing shoulder surgery, but it is associated with high rates of diaphragmatic dysfunction. Performing the block more distally, at the level of the superior trunk, may reduce the incidence of phrenic nerve palsy. We hypothesized that superior trunk block would result in diaphragmatic paralysis rate of less than 20%.Methods30 patients undergoing arthroscopic shoulder surgery received superior trunk block under ultrasound guidance. Measurements of diaphragm excursion were determined with ultrasound prior to the block, 15 min after the block, and postoperatively in phase II of postanesthesia care unit, in conjunction with clinical parameters of respiratory function.Results10 patients (33.3%, 95% CI 17.3% to 52.8%) developed complete hemidiaphragmatic paralysis at the postoperative assessment. An additional eight patients (26.7%) developed paresis without paralysis. Of the 18 patients with diaphragm effects, seven (38.9%) reported dyspnea. 83.3% of patients with abnormal diaphragm motion (56.7% of the total sample) had audibly reduced breath sounds on auscultation. Oxygen saturation measurements did not correlate with diaphragm effect and were not significantly reduced by the postoperative assessment.ConclusionAlthough injection of local anesthetic at the superior trunk level is associated with less diaphragmatic paralysis compared with traditional interscalene block, a significant portion of patients will continue to have ultrasonographic and clinical evidence of diaphragmatic weakness or paralysis.

Depth of cervical plexus block and phrenic nerve blockade: a randomized trial

Background and objectivesCervical plexus blocks are commonly used to facilitate carotid endarterectomy (CEA) in the awake patient. These blocks can be divided into superficial, intermediate, and deep blocks by their relation to the fasciae of the neck. We hypothesized that the depth of block would have a significant impact on phrenic nerve blockade and consequently hemi-diaphragmatic motion.MethodsWe enrolled 45 patients in an observer blinded randomized controlled trial, scheduled for elective, awake CEA. Patients received either deep, intermediate, or superficial cervical plexus blocks, using 20 mL of 0.5% ropivacaine mixed with an MRI contrast agent. Before and after placement of the block, transabdominal ultrasound measurements of diaphragmatic movement were performed. Patients underwent MRI of the neck to evaluate spread of the injectate, as well as lung function measurements. The primary outcome was ipsilateral difference of hemi-diaphragmatic motion during forced inspiration between study groups.ResultsPostoperatively, forced inspiration movement of the ipsilateral diaphragm (4.34±1.06, 3.86±1.24, 2.04±1.20 (mean in cm±SD for superficial, intermediate and deep, respectively)) was statistically different between block groups (p<0.001). Differences were also seen during normal inspiration. Lung function, oxygen saturation, complication rates, and patient satisfaction did not differ. MRI studies indicated pronounced permeation across the superficial fascia, but nevertheless easily distinguishable spread of injectate within the targeted compartments.ConclusionsWe studied the characteristics and side effects of cervical plexus blocks by depth of injection. Diaphragmatic dysfunction was most pronounced in the deep cervical plexus block group.Trial registration numberEudraCT 2017-001300-30.

Novel approach for pericapsular radiofrequency ablation of sacrococcygeal junction for patients with coccydynia

IntroductionCoccydynia is a multifactorial complex clinical challenge. A multimodal approach with both conservative measures and procedural interventions is often recommended. We described a novel approach of radiofrequency (RF) ablation for the management of coccydynia.MethodsThree patients with known history of coccydynia refractory to conservative therapy were referred to our clinic. All received different types of RF ablation before: one with anterior bipolar lesion with no analgesia benefit, one with posterior stripped lesion with good benefit but only after 8 weeks of pain flare and one received anterior monopolar lesion with 50% pain reduction for 2–3 months. All subjects underwent a novel RF ablation to the anterior surface of the sacrococcygeal and intercoccygeal joints with two bipolar lesions using multi-tined needles under fluoroscopy guidance. One bipolar lesion was between two needles: one in the sacrococcygeal and another in the intercoccygeal (between first and second coccyx) joints. Another bipolar lesion was between needles on both side of the sacrococcygeal joint.ResultsAll experienced at least 65% pain relief for 6 months. The sitting endurance increased from less than 5 min to an average of 70 min. No adverse effect was observed in two and in the patient who used to have pain flare after lesioning, the pain flare lasted only for 2 weeks.DiscussionThe configuration of the two bipolar lesions with multi-tined needles in this case series stimulates the thinking of new approach for the ablation technique for pain from coccyx. Further prospective large case cohort study is needed.

Efficacy of topical cannabinoids in the management of pain: a systematic review and meta-analysis of animal studies

Background/importanceCannabinoids are emerging as an alternative pain management option, preliminarily supported by preclinical and clinical studies. Unwanted side effects from oral or inhaled cannabinoids remain, however, a major barrier to widespread use. Peripherally acting cannabinoids (eg, topically applied) may circumvent these side effects while providing localized pain management.ObjectiveOur purpose was to systematically review the literature on the effectiveness of peripherally acting cannabinoids for pain management.Evidence reviewWe searched MEDLINE, EMBASE, CENTRAL, CINAHL, and PubMed databases. Included studies examined the effect of topical/peripherally administered cannabinoids on pain ratings in humans, as well as pain-related outcomes in animals (eg, paw withdrawal). Due to a lack of trials, human studies were summarized in a narrative synthesis. Separate meta-analyses were performed for animal studies using radiant tail flick or paw withdrawal outcomes.FindingsOur search yielded 1182 studies following removal of duplicates, with 46 studies (6 human, 40 animal) included. Human studies (one randomized controlled trial and five case studies/series) reported no adverse events to topical cannabinoids and preliminary evidence of decreased pain ratings. Animal studies reporting tail flick (5) (2.81, 95% CI 1.93 to 3.69, p<0.001) and mechanical withdrawal (11) (2.74, 95% CI 1.82 to 3.67, p<0.001) reported prolonged responses (analgesia) in peripheral cannabinoid groups compared with controls.ConclusionsPreclinical animal studies provided low-quality evidence for peripherally administered cannabinoids to provide regional, antinociceptive effects. The scarcity of high-quality human studies underscores the need to translate preclinical evidence into well-controlled human trials.

Neuraxial and general anesthesia for outpatient total joint arthroplasty result in similarly low rates of major perioperative complications: a multicentered cohort study

BackgroundNeuraxial anesthesia when compared with general anesthesia has shown to improve outcomes following lower extremity total joint arthroplasty. It is unclear whether these benefits are present in outpatient surgery given the selection of healthier patients.ObjectiveTo compare the effects of neuraxial versus general anesthesia on outcomes following ambulatory hip and knee arthroplasty.MethodsMulticentered retrospective cohort study in ambulatory hip or knee arthroplasty patients between January 2017 and December 2019. Primary endpoint examined 30-day major postoperative complications (mortality, myocardial infarction, deep venous thromboembolism, pulmonary embolism, stroke, and acute renal failure).ResultsOf 11 523 eligible patients identified, 10 003 received neuraxial anesthesia, while 1520 received general anesthesia. 30-day major complications did not differ between neuraxial anesthesia and general anesthesia groups (1.8% vs 2.3%; aOR=0.85, CI: 0.56 to 1.27, p=0.39). There was no difference in 30-day minor complications (surgical site infection, pneumonia, urinary tract infection; 3.3% vs 4.1%; aOR=0.83, CI: 0.62 to 1.14, p=0.23). The neuraxial group demonstrated reduced pain and analgesia requirements and had less postoperative nausea and vomiting (PONV). Median recovery room length of stay was shorter by 52 min in the general anesthesia group, but these patients were more likely to fail same day discharge (33% vs 23.4%; p<0.01).ConclusionAnesthesia type was not associated with an increased risk for complications. However, neuraxial anesthesia improved outcomes that predict readiness for discharge: patients had less pain, required less opioids, and had a lower incidence of PONV, thus improving the rate of same day discharge.Trial registration numberNCT04203732.