Perioperative and anesthetic considerations for the management of neuromodulation systems.

The use of neuromodulation systems is increasing for the treatment of various pathologies ranging from movement disorders to urinary incontinence to chronic pain syndromes. While the type of neuromodulation devices varies, they are largely categorized as intracranial (eg, deep brain stimulation), neuraxial (eg, spinal cord stimulation, dorsal root ganglion stimulation, and intrathecal drug delivery systems), or peripheral (eg, sacral nerve stimulation and peripheral nerve stimulation) systems. Given the increasing prevalence of these systems in the overall population, it is important for anesthesiologists, surgeons, and the perioperative healthcare team to familiarize themselves with these systems and their unique perioperative considerations. In this review, we explore and highlight the various neuromodulation systems, their general perioperative considerations, and notable special circumstances for perioperative management.

Regional anesthesia techniques and postoperative delirium: systematic review and meta-analysis.

INTRODUCTION: Postoperative delirium is a frequent occurrence in the elderly surgical population. As a comprehensive list of predictive factors remains unknown, an opioid-sparing approach incorporating regional anesthesia techniques has been suggested to decrease its incidence. Due to the lack of conclusive evidence on the topic, we conducted a systematic review and meta-analysis to investigate the potential impact of regional anesthesia and analgesia on postoperative delirium. EVIDENCE ACQUISITION: PubMed, Embase, and the Cochrane central register of Controlled trials (CENTRAL) databases were searched for randomized trials comparing regional anesthesia or analgesia to systemic treatments in patients having any type of surgery. This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We pooled the results separately for each of these two applications by random effects modelling. Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to evaluate the certainty of evidence and strength of conclusions. EVIDENCE SYNTHESIS: Eighteen trials (3361 subjects) were included. Using regional techniques for surgical anesthesia failed to reduce the risk of postoperative delirium, with a relative risk (RR) of 1.21 (95% CI: 0.79 to 1.85); P=0.3800. In contrast, regional analgesia reduced the relative risk of perioperative delirium by a RR of 0.53 (95% CI: 0.42 to 0.68; P<0.0001), when compared to systemic analgesia. Post-hoc subgroup analysis for hip fracture surgery yielded similar findings. CONCLUSIONS: These results show that postoperative delirium may be decreased when regional techniques are used in the postoperative period as an analgesic strategy. Intraoperative regional anesthesia alone may not decrease postoperative delirium since there are other factors that may influence this outcome.

The expanding role of chronic pain interventions in multimodal perioperative pain management: a narrative review.

Surgery is a risk factor for chronic pain and long-term opioid use. As perioperative pain management continues to evolve, treatment modalities traditionally used for chronic pain therapy may provide additional benefit to patients undergoing surgery. Interventions such as radiofrequency ablation, cryoneurolysis, and neuromodulation may potentially be used in conjunction with acute pain procedures such as nerve blocks and multimodal analgesia. Pharmacological agents associated with chronic pain medicine, including gabapentinoids, ketamine, and selective serotonin reuptake inhibitors, may be useful adjuncts in perioperative pain management when indicated. There may also be a role for acupuncture, music therapy, and other integrative medicine therapies. A transitional pain service can help coordinate outpatient care with inpatient perioperative pain management and promote a more personalized and comprehensive approach that can improve postoperative outcomes.

Regional anesthesia educational material utilization varies by World Bank income category: A mobile health application data study.

INTRODUCTION: Regional anesthesia offers an alternative to general anesthesia and may be advantageous in low resource environments. There is a paucity of data regarding the practice of regional anesthesia in low- and middle-income countries. Using access data from a free Android app with curated regional anesthesia learning modules, we aimed to estimate global interest in regional anesthesia and potential applications to clinical practice stratified by World Bank income level. METHODS: We retrospectively analyzed data collected from the free Android app "Anesthesiologist" from December 2015 to April 2020. The app performs basic anesthetic calculations and provides links to videos on performing 12 different nerve blocks. Users of the app were classified on the basis of whether or not they had accessed the links. Nerve blocks were also classified according to major use (surgical block, postoperative pain adjunct, rescue block). RESULTS: Practitioners in low- and middle-income countries accessed the app more frequently than in high-income countries as measured by clicks. Users from low- and middle-income countries focused mainly on surgical blocks: ankle, axillary, infraclavicular, interscalene, and supraclavicular blocks. In high-income countries, more users viewed postoperative pain blocks: adductor canal, popliteal, femoral, and transverse abdominis plane blocks. Utilization of the app was constant over time with a general decline with the start of the COVID-19 pandemic. CONCLUSION: The use of an in app survey and analytics can help identify gaps and opportunities for regional anesthesia techniques and practices. This is especially impactful in limited-resource areas, such as lower-income environments and can lead to targeted educational initiatives.

Daring discourse - no: cannabinoids should not be used for acute postoperative pain management.

As anesthesiologists and acute pain medicine specialists, we will care for patients in the perioperative period who use cannabinoids for chronic pain and/or marijuana recreationally. We will have to address difficult questions from patients regarding the potential applications for cannabinoids in acute pain management. While we must remain compassionate and understand our patients' desire to find relief from suffering using available non-opioid medications, we are ethically bound to do no harm and provide them with treatment options supported by the best available evidence. Today, we cannot support cannabinoids in the management of acute postoperative pain.

Implementation of the IPACK (Infiltration between the Popliteal Artery and Capsule of the Knee) block into a multimodal analgesic pathway for total knee replacement.

BACKGROUND: The Infiltration between the Popliteal Artery and Capsule of the Knee (IPACK) block is a new anesthesiologist- administered analgesic technique for controlling posterior knee pain that has not yet been well studied in total knee arthroplasty (TKA) patients. We compared pain outcomes in TKA patients before and after implementation of the IPACK with the hypothesis that patients receiving IPACK blocks will report lower pain scores on postoperative day (POD) 0 than non-IPACK patients. METHODS: With Institutional Review Board approval, we retrospectively reviewed data for consecutive TKA patients by a single surgeon 4 months before (PRE) and after (POST) IPACK implementation. All TKA patients received adductor canal catheters and peri-operative multimodal analgesia. The primary outcome was pain on POD 0. Other outcomes were daily pain scores, opioid consumption, ambulation distance, length of stay, and adverse events within 30 days. RESULTS: Post-implementation, 48/50 (96%) of TKA patients received an IPACK block, and they were compared with 32 patients in the PRE group. On POD 0, the lowest pain score (median [10th-90th percentiles]) was significantly lower for the POST group compared to the PRE group (0 [0-4.3] vs. 2.5 [0-7]; P = 0.003). The highest patient-reported pain scores on any POD were similar between groups with no differences in other outcomes. CONCLUSIONS: Within a multimodal analgesic protocol, addition of IPACK blocks decreased the lowest pain scores on POD 0. Although other outcomes were unchanged, there may be a role for new opioid-sparing analgesic techniques, and changing clinical practice change can occur rapidly.

Do Hospitals Performing Frequent Neuraxial Anesthesia for Hip and Knee Replacements Have Better Outcomes?

BACKGROUND: Neuraxial anesthesia is increasingly recommended for hip/knee replacements as some studies show improved outcomes on the individual level. With hospital-level studies lacking, we assessed the relationship between hospital-level neuraxial anesthesia utilization and outcomes. METHODS: National data on 808,237 total knee and 371,607 hip replacements were included (Premier Healthcare 2006 to 2014; 550 hospitals). Multivariable associations were measured between hospital-level neuraxial anesthesia volume (subgrouped into quartiles) and outcomes (respiratory/cardiac complications, blood transfusion/intensive care unit need, opioid utilization, and length/cost of hospitalization). Odds ratios (or percent change) and 95% CI are reported. Volume-outcome relationships were additionally assessed by plotting hospital-level neuraxial anesthesia volume against predicted hospital-specific outcomes; trend tests were applied with trendlines' R statistics reported. RESULTS: Annual hospital-specific neuraxial anesthesia volume varied greatly: interquartile range, 3 to 78 for hips and 6 to 163 for knees. Increasing frequency of neuraxial anesthesia was not associated with reliable improvements in any of the study's clinical outcomes. However, significant reductions of up to -14.1% (95% CI, -20.9% to -6.6%) and -15.6% (95% CI, -22.8% to -7.7%) were seen for hospitalization cost in knee and hip replacements, respectively, both in the third quartile of neuraxial volume. This coincided with significant volume effects for hospitalization cost; test for trend P < 0.001 for both procedures, R 0.13 and 0.41 for hip and knee replacements, respectively. CONCLUSIONS: Increased hospital-level use of neuraxial anesthesia is associated with lower hospitalization cost for lower joint replacements. However, additional studies are needed to elucidate all drivers of differences found before considering hospital-level neuraxial anesthesia use as a potential marker of quality.

Interfascial Plane Blocks: Back to Basics.

Ultrasound-guided interfascial plane blocks are a recent development in modern regional anesthesia research and practice and represent a new route of transmission for local anesthetic to various anatomic locations, but much more research is warranted. Before becoming overtaken with enthusiasm for these new techniques, a deeper understanding of fascial tissue anatomy and structure, as well as precise targets for needle placement, is required. Many factors may influence the ultimate spread and quality of resulting interfascial plane blocks, and these must be understood in order to best integrate these techniques into contemporary perioperative pain management protocols.

Acute Pain Medicine in the United States: A Status Report.

BACKGROUND: Consensus indicates that a comprehensive,multimodal, holistic approach is foundational to the practice of acute pain medicine (APM),but lack of uniform, evidence-based clinical pathways leads to undesirable variability throughout U. S. healthcare systems. Acute pain studies are inconsistently synthesized to guide educational programs. Advanced practice techniques involving regional anesthesia assume the presence of a physician-led, multidisciplinary acute pain service,which is often unavailable or inconsistently applied.This heterogeneity of educational and organizational standards may result in unnecessary patient pain and escalation of healthcare costs. METHODS: A multidisciplinary panel was nominated through the APM Shared Interest Group of the American Academy of Pain Medicine. The panel met in Chicago, IL, in July 2014, to identify gaps and set priorities in APM research and education. RESULTS: The panel identified three areas of critical need: 1) an open-source acute pain data registry and clinical support tool to inform clinical decision making and resource allocation and to enhance research efforts; 2) a strong professional APM identity as an accredited subspecialty; and 3) educational goals targeted toward third-party payers,hospital administrators, and other key stake holders to convey the importance of APM. CONCLUSION: This report is the first step in a 3-year initiative aimed at creating conditions and incentives for the optimal provision of APM services to facilitate and enhance the quality of patient recovery after surgery, illness, or trauma. The ultimate goal is to reduce the conversion of acute pain to the debilitating disease of chronic pain.

A pilot study to assess adductor canal catheter tip migration in a cadaver model.

An adductor canal catheter may facilitate early ambulation after total knee arthroplasty, but there is concern over preoperative placement since intraoperative migration of catheters may occur from surgical manipulation and result in ineffective analgesia. We hypothesized that catheter type and subcutaneous tunneling may influence tip migration for preoperatively inserted adductor canal catheters. In a male unembalmed human cadaver, 20 catheter insertion trials were divided randomly into one of four groups: flexible epidural catheter either tunneled or not tunneled; or rigid stimulating catheter either tunneled or not tunneled. Intraoperative patient manipulation was simulated by five range-of-motion exercises of the knee. Distance and length measurements were performed by a blinded regional anesthesiologist. Changes in catheter tip to nerve distance (p = 0.225) and length of catheter within the adductor canal (p = 0.467) were not different between the four groups. Two of five non-tunneled stimulating catheters (40 %) were dislodged compared to 0/5 in all other groups (p = 0.187). A cadaver model may be useful for assessing migration of regional anesthesia catheters; catheter type and subcutaneous tunneling may not affect migration of adductor canal catheters based on this preliminary study. However, future studies involving a larger sample size, actual patients, and other catheter types are warranted.

A retrospective comparative provider workload analysis for femoral nerve and adductor canal catheters following knee arthroplasty.

Adductor canal catheters preserve quadriceps strength better than femoral nerve catheters and may facilitate postoperative ambulation following total knee arthroplasty. However, the effect of this newer technique on provider workload, if any, is unknown. We conducted a retrospective provider workload analysis comparing these two catheter techniques; all other aspects of the clinical pathway remained the same. The primary outcome was number of interventions recorded per patient postoperatively. Secondary outcomes included infusion duration, ambulation distance, opioid consumption, and hospital length of stay. Adductor canal patients required a median (10-90th percentiles) of 0.0 (0.0-2.6) interventions compared to 1.0 (0.3-3.0) interventions for femoral patients (p < 0.001); 18/23 adductor canal patients (78 %) compared to 2/22 femoral patients (9 %) required no interventions (p < 0.001). Adductor canal catheter infusions lasted 2.0 (1.4-2.0) days compared to 1.5 (1.0-2.7) days in the femoral group (p = 0.016). Adductor canal patients ambulated further [mean (SD)] than femoral patients on postoperative day 1 [24.5 (21.7) vs. 11.9 (14.6) meters, respectively; p = 0.030] and day 2 [44.9 (26.3) vs. 22.0 (22.2) meters, respectively; p = 0.003]. Postoperative opioid consumption and length of stay were similar between groups. We conclude that adductor canal catheters offer both patient and provider benefits when compared to femoral nerve catheters.

A randomized clinical trial comparing the effectiveness of ultrasound guidance versus nerve stimulation for lateral popliteal-sciatic nerve blocks in obese patients.

OBJECTIVES: Ultrasound guidance may decrease the procedural time for many peripheral nerve blocks compared to nerve stimulation, but these studies have generally excluded obese patients. This single-blinded randomized clinical trial was designed to compare procedural times and related outcomes for ultrasound- versus nerve stimulation-guided lateral popliteal-sciatic nerve blockade specifically in obese patients. METHODS: With Institutional Review Board approval and informed consent, patients with a body mass index greater than 30 kg/m(2) who were scheduled for foot/ankle surgery and desiring a peripheral nerve block were offered enrollment. Study patients were randomly assigned to receive a lateral popliteal-sciatic nerve block under either ultrasound or nerve stimulation guidance. The patient and assessor were blinded to group assignment. The primary outcome was procedural time in seconds. Secondary outcomes included number of needle redirections, procedure-related pain, patient satisfaction with the block, success rate, sensory and motor onset times, block duration, and complication rates. RESULTS: Twenty-four patients were enrolled and completed the study. All patients had successful nerve blocks. The mean procedural times (SD) were 577 (57) seconds under nerve stimulation and 206 (40) seconds with ultrasound guidance (P< .001; 95% confidence interval for difference, 329-412 seconds). Patients in the ultrasound group had fewer needle redirections and less procedure-related pain, required less opioids, and were more satisfied with their block procedures. There were no statistically significant differences in other outcomes. CONCLUSIONS: The results of this study show that, for obese patients undergoing lateral popliteal-sciatic nerve blocks, ultrasound guidance reduces the procedural time and procedure-related pain and increases patient satisfaction compared to nerve stimulation while providing similar block characteristics.

Choice of loco-regional anesthetic technique affects operating room efficiency for carpal tunnel release.

Intravenous regional anesthesia (Bier block) is indicated for minor procedures such as carpal tunnel release but must be performed in the operating room. We hypothesize that preoperative peripheral nerve blocks decrease anesthesia-controlled time compared to Bier block for carpal tunnel release. With IRB approval, we reviewed surgical case data from a tertiary care university hospital outpatient surgery center for 1 year. Unilateral carpal tunnel release cases were grouped by anesthetic technique: (1) preoperative nerve blocks, or (2) Bier block. The primary outcome was anesthesia-controlled time (minutes). Secondary outcomes included surgical time and time for nerve block performance in minutes, when applicable. Eighty-nine cases met criteria for analysis (40 nerve block and 49 Bier block). Anesthesia-controlled time [median (10th-90th percentiles)] was shorter for the nerve block group compared to Bier block [11 (6-18) vs. 13 (9-20) min, respectively; p = 0.02). Surgical time was also shorter for the nerve block group vs. the Bier block group [13 (8-21) and 17 (10-29) min, respectively; p < 0.01), but nerve blocks took 10 (5-28) min to perform. Ultrasound-guided nerve blocks performed preoperatively reduce anesthesia-controlled time compared to Bier block and may be a useful anesthetic modality in some practice environments.