T. Edward Kim

Continuous femoral versus posterior lumbar plexus nerve blocks for analgesia after hip arthroplasty: a randomized, controlled study.

BACKGROUND:Hip arthroplasty frequently requires potent postoperative analgesia, often provided with an epidural or posterior lumbar plexus local anesthetic infusion. However, American Society of Regional Anesthesia guidelines now recommend against epidural and continuous posterior lumbar plexus blocks during administration of various perioperative anticoagulants often administered after hip arthroplasty. A continuous femoral nerve block is a possible analgesic alternative, but whether it provides comparable analgesia to a continuous posterior lumbar plexus block after hip arthroplasty remains unclear. We therefore tested the hypothesis that differing the catheter insertion site (femoral versus posterior lumbar plexus) after hip arthroplasty has no impact on postoperative analgesia. METHODS:Preoperatively, subjects undergoing hip arthroplasty were randomly assigned to receive either a femoral or a posterior lumbar plexus stimulating catheter inserted 5 to 15 cm or 0 to 1 cm past the needle tip, respectively. Postoperatively, patients received perineural ropivacaine, 0.2% (basal 6 mL/hr, bolus 4 mL, 30-minute lockout) for at least 2 days. The primary end point was the average daily pain scores as measured with a numeric rating scale (0–10) recorded in the 24-hour period beginning at 07:30 the morning after surgery, excluding twice-daily physical therapy sessions. Secondary end points included pain during physical therapy, ambulatory distance, and supplemental analgesic requirements during the same 24-hour period, as well as satisfaction with analgesia during hospitalization. RESULTS:The mean (SD) pain scores for subjects receiving a femoral infusion (n = 25) were 3.6 (1.8) versus 3.5 (1.8) for patients receiving a posterior lumbar plexus infusion (n = 22), resulting in a group difference of 0.1 (95% confidence interval −0.9 to 1.2; P = 0.78). Because the confidence interval was within a prespecified −1.6 to 1.6 range, we conclude that the effect of the 2 analgesic techniques on postoperative pain was equivalent. Similarly, we detected no differences between the 2 treatments with respect to the secondary end points, with one exception: subjects with a femoral catheter ambulated a median (10th–90th percentiles) 2 (0–17) m the morning after surgery, in comparison with 11 (0–31) m for subjects with a posterior lumbar plexus catheter (data nonparametric; P = 0.02). CONCLUSIONS:After hip arthroplasty, a continuous femoral nerve block is an acceptable analgesic alternative to a continuous posterior lumbar plexus block when using a stimulating perineural catheter. However, early ambulatory ability suffers with a femoral infusion.

A Randomized Comparison of Long-and Short-Axis Imaging for In-Plane Ultrasound-Guided Femoral Perineural Catheter Insertion

Continuous femoral nerve blocks provide effective analgesia after knee arthroplasty, and infusion effects depend on reliable catheter location. Ultrasound‐guided perineural catheter insertion using a short‐axis in‐plane technique has been validated, but the optimal catheter location relative to target nerve and placement orientation remain unknown. We hypothesized that a long‐axis in‐plane technique for femoral perineural catheter insertion results in faster onset of sensory anesthesia compared to a short‐axis in‐plane technique.

An In Vitro Study to Evaluate the Utility of the “Air Test” to Infer Perineural Catheter Tip Location

Injection of air under ultrasound guidance via a perineural catheter after insertion (“air test”) has been described as a means to infer placement accuracy, yet this test has never been rigorously evaluated. We tested the hypothesis that the air test predicts accurate catheter location greater than chance and determined the tests sensitivity, specificity, and positive and negative predictive values using a porcine‐bovine model and blinded expert in ultrasound‐guided regional anesthesia. The air test improved the expert clinicians assessment of catheter tip position compared to chance, but there was no difference when compared to direct visualization of the catheter without air injection.

A randomized comparison of proximal and distal ultrasound-guided adductor canal catheter insertion sites for knee arthroplasty.

Proximal and distal (mid‐thigh) ultrasound‐guided continuous adductor canal block techniques have been described but not yet compared, and infusion benefits or side effects may be determined by catheter location. We hypothesized that proximal placement will result in faster onset of saphenous nerve anesthesia, without additional motor block, compared to a distal technique.

Why the Perioperative Surgical Home Makes Sense for Veterans Affairs Health Care.

• Volume 120 • Number 5 www.anesthesia-analgesia.org 1163 Copyright

Design and Implementation of a Perioperative Surgical Home at a Veterans Affairs Hospital

The innovative Perioperative Surgical Home model aims to optimize the outcomes of surgical patients by leveraging the expertise and leadership of physician anesthesiologists, but there is a paucity of practical examples to follow. Veterans Affairs health care, the largest integrated system in the United States, may be the ideal environment in which to explore this model. We present our experience implementing Perioperative Surgical Home at one tertiary care university-affiliated Veterans Affairs hospital. This process involved initiating consistent postoperative patient follow-up beyond the postanesthesia care unit, a focus on improving in-hospital acute pain management, creation of an accessible database to track outcomes, developing new clinical pathways, and recruiting additional staff. Today, our Perioperative Surgical Home facilitates communication between various services involved in the care of surgical patients, monitoring of patient outcomes, and continuous process improvement.

Preliminary Study of Ergonomic Behavior During Simulated Ultrasound-Guided Regional Anesthesia Using a Head-Mounted Display

A head‐mounted display provides continuous real‐time imaging within the practitioners visual field. We evaluated the feasibility of using head‐mounted display technology to improve ergonomics in ultrasound‐guided regional anesthesia in a simulated environment. Two anesthesiologists performed an equal number of ultrasound‐guided popliteal‐sciatic nerve blocks using the head‐mounted display on a porcine hindquarter, and an independent observer assessed each practitioners ergonomics (eg, head turning, arching, eye movements, and needle manipulation) and the overall block quality based on the injectate spread around the target nerve for each procedure. Both practitioners performed their procedures without directly viewing the ultrasound monitor, and neither practitioner showed poor ergonomic behavior. Head‐mounted display technology may offer potential advantages during ultrasound‐guided regional anesthesia.

The Perioperative Surgical Home model facilitates change implementation in anesthetic technique within a clinical pathway for total knee arthroplasty.

BACKGROUND The challenge of knowledge translation in medical settings is well known, and implementing change in clinical practice can take years. For the increasing number total knee arthroplasty (TKA) patients annually, there is ample evidence to endorse neuraxial anesthesia over general anesthesia. The rate of adoption of this practice, however, is slow at the current time. We hypothesized that a Perioperative Surgical Home (PSH) model facilitates rapid change implementation in anesthesia. METHODS The PSH clinical pathways workgroup at a tertiary care Veterans Affairs hospital embarked on a 5-month process of changing the preferred anesthetic technique for patients undergoing TKA. This process involved multiple sequential steps: literature review; development of a work document; training of staff; and prospective collection of data. To assess the impact of this change, we examined data 6 months before (PRE, n=90) and after (POST) change implementation (n=128), and our primary outcome was the overall proportion of spinal anesthesia usage for each 6 month period. Secondary outcomes included minor and major complications associated with anesthetic technique. RESULTS Over a period of one year, there was an increase in the proportion of patients who received spinal anesthesia (13% vs. 63%, p<0.001). For the following year, 53-92% of TKA patients per month received spinal anesthesia. There were no differences in major complications. CONCLUSION Rapid and sustained change implementation in clinical anesthesia practice based on emerging evidence is feasible. IMPLICATIONS Perioperative Surgical Home model may facilitate rapid change implementation in surgical care. LEVEL OF EVIDENCE Cohort study, Level 2.

Application of Echogenic Technology for Catheters Used in Ultrasound-Guided Continuous Peripheral Nerve Blocks

Limited data exist regarding the echogenicity of perineural catheters, but visualization is crucial to ensure accurate placement and efficacy of the subsequent local anesthetic infusion. The objective of this study was to determine the comparative echogenicity of various regional anesthesia catheters. In an in vitro porcine‐bovine model, we compared the echogenic qualities of 3 commercially available regional anesthesia catheters and 1 catheter under development to optimize echogenicity. Outcomes included visual echogenicity ranking, image quality, and scanning time, as assessed by 2 blinded investigators. The experimental catheter was found to be more echogenic than 2 of the 3 comparators.

Adherence to a Multimodal Analgesic Clinical Pathway: A Within-Group Comparison of Staged Bilateral Knee Arthroplasty Patients

Background and Objectives Multimodal analgesic clinical pathways for joint replacement patients often include perineural catheters, but long-term adherence to these pathways has not yet been investigated. Our primary aim was to determine adherence rate to a knee arthroplasty clinical pathway for patients undergoing staged bilateral procedures. Methods This study was performed at a hospital with a Perioperative Surgical Home program and knee arthroplasty clinical pathway using multimodal analgesia and adductor canal catheters. Data were examined for all orthopedic surgery patients over a 4-year period. We included patients who had staged bilateral knee arthroplasty electively scheduled on 2 separate dates. The primary outcome was rate of adductor canal catheter utilization as a measure of adherence to the clinical pathway. Other outcomes included rates of neuraxial anesthesia and minor and major perioperative complications. Results We analyzed data for 103 unique patients. The interval between surgeries was a median of 261 days (10th–90th percentile, 138–534 days). All 103 patients had adductor canal catheters for both the first and second surgeries (P > 0.999). Forty-one percent of patients had the same surgeon for both surgeries, but only 2% had the same anesthesiologist (P < 0.001). From the first to the second surgery, utilization of neuraxial anesthesia increased from 51% to 68%, respectively (P = 0.005). There were no differences in minor or major complications. Conclusions For staged bilateral knee arthroplasty patients, 100% clinical pathway adherence including perineural catheters and multimodal analgesia is feasible despite multiple variables. We believe that patient-centered acute pain management requires consistent and reliable delivery of care.