Migration rate of proximal adductor canal block catheters placed parallel versus perpendicular to the nerve after total knee arthroplasty: a randomized controlled study

BACKGROUND

Perineural catheters placed parallel to the nerve course are reported to have lower migration rates than those placed perpendicular to it. However, catheter migration rates for a continuous adductor canal block (ACB) remain unknown. This study compared postoperative migration rates of proximal ACB catheters placed parallel and perpendicular to the saphenous nerve.

METHODS

Seventy participants scheduled for unilateral primary total knee arthroplasty were randomly assigned for parallel or perpendicular placement of the ACB catheter. The primary outcome was the migration rate of the ACB catheter on postoperative day (POD) 2. Catheter migration was defined as being unable to confirm saline administration via the catheter around the saphenous nerve at the mid-thigh level under ultrasound guidance. Secondary outcomes included active and passive range of motion (ROM) of the knee on postoperative rehabilitation.

RESULTS

Sixty-seven participants were included in the final analyses. The catheter migrated significantly less often in the parallel group (5 of 34 (14.7%)) than in the perpendicular group (24 of 33 (72.7%)) (p<0.001). The mean (SD) active and passive knee flexion ROM (degrees) improved significantly in the parallel than in the perpendicular group (POD 1: active, 88.4 (13.2) vs 80.0 (12.4), p=0.011; passive, 95.6 (12.8) vs 85.7 (13.6), p=0.004; POD 2: active, 88.7 (13.4) vs 82.2 (11.5), p=0.036; passive, 97.2 (12.8) vs 91.0 (12.0), p=0.045).

CONCLUSION

Parallel placement of the ACB catheter provided a lower postoperative catheter migration rate than perpendicular placement of the ACB catheter along with corresponding improvements in ROM and secondary analgesic outcomes.

TRIAL REGISTRATION NUMBER

UMIN000045374.

Adductor canal block with a suture-method catheter - A parallel or perpendicular approach?

BACKGROUND

We performed a randomised blinded pilot study in 16 healthy volunteers to assess whether placing a suture-method catheter in the adductor canal is feasible with two different insertion techniques.

METHODS

Each volunteer had a suture-method catheter placed approximately halfway between the superior anterior iliac spine and base of the patella in both legs. Catheters were placed using a parallel technique in one leg and a perpendicular technique in the other leg, according to randomisation. 15 mL lidocaine 1% was injected in each catheter. Successful placement was defined as loss of cold sensation in the saphenous area 30 min after injection. Volunteers were sent home and returned the following day and another dose of lidocaine (15 mL, 1%) was injected through the catheters. Catheter displacement distance was assessed by ultrasound and cold sensation was assessed. In case of preserved cold sensation, we attempted to reposition the catheter with a subsequent injection of lidocaine and reassessment of cold sensation.

RESULTS

All primary placements were successful using the perpendicular approach (100%; 95% CI 81%-100%) whereas one placement failed using the parallel approach (94%; 95% CI 72%-99%). Three catheters placed using the perpendicular approach were displaced on day 2, compared to one catheter placed with the parallel approach. Displacement distance was highly variable. All catheters, except one, could be repositioned. Three volunteers reported transient sensory deficits lasting approximately 6-8 weeks.

CONCLUSION

The suture-method catheter can be placed in the adductor canal with high success rates for initial placement with both techniques.

Ultrasound guided repositioning of a new suture-method catheter for adductor canal block - a randomized pilot study in healthy volunteers

BACKGROUND

We performed a randomized, blinded pilot study in 12 volunteers to assess the feasibility to reposition an intentionally displaced suture-method catheter for two different insertion techniques for adductor canal block.

METHODS

Each volunteer had an ultrasound-guided suture-method catheter placed in the adductor canal (AC) in both legs. The catheters were placed using a perpendicular technique in one leg and a parallel technique in the other leg, according to randomization. 15 mL lidocaine 1% (LA) was injected in each catheter. Successful primary placement was defined as combined LA spread within the AC and loss of cold sensation 15 min after injection. All catheters were intentionally displaced, and subsequently repositioned using ultrasound. Another dose of lidocaine (15 mL 1%) was injected through the catheters and assessed for successful repositioning.

RESULTS

Successful primary placement was achieved in 83% (95% CI 55-95%) of catheters placed perpendicular to the AC, and in 75% (95% CI 47-91%) of catheters placed parallel to the AC. Of those with successful primary placement, 100% (95% CI 72-100%) of catheters placed perpendicular to the AC, and 67% (95% CI 35-88%)) placed parallel to the AC could be repositioned.

CONCLUSIONS

Placement and secondary repositioning after displacement of a suture-method catheter within the adductor canal is achievable. A perpendicular technique seems more reliable.

TRIAL REGISTRATION

NCT03315481 clinicaltrials.gov . The study was submitted on March 1, 2017. Due to clerical error, the study was posted on October 20, 2017.

Paths of femoral nerve catheters placed using ultrasound-guided in plane vs out of plane techniques: A randomized controlled clinical trial

BACKGROUND

Continuous blockade of the femoral nerve is widely used for postoperative analgesia after hip surgery. It can be achieved by ultrasound-guided placement of a femoral nerve catheter via either the in plane (IP) or out of plane (OOP) technique. On the basis of postoperative radiographs, we evaluated the paths of femoral nerve catheters with respect to both techniques and its effect on postoperative analgesia.

METHODS

Thirty-four patients were randomized to receive a radiopaque femoral nerve catheter via either the IP or OOP technique. The paths and tip position of the catheters were evaluated in postoperative frontal radiographs of the operated hip joint concerning a predefined target region and four neighboring regions. Pain scores were assessed using a numeric rating scale (0-10).

RESULTS

Sixteen IP patients and 18 OOP patients were included in the study. The catheter path was radiographically evaluated in 13 IP patients and in 10 OOP patients. The catheter tips were located within the target region in 39% of the IP group and in 50% of the OOP group. The catheter tip was 0.00 cm [-3.80 to 3.84] and -1.19 cm [-12.27 to 0.00] (median [range]) from the target region in the OOP group and IP group, respectively (P = .045). Catheters flipped distally more often in the IP group (IP: 61.5%, OOP: 10.0%; P = .01). There were no marked differences in the pain scores of either group.

CONCLUSION

Femoral nerve catheters inserted by the ultrasound-guided IP technique flip distally more frequently than catheters inserted by the OOP technique. Moreover, the distance between the catheter tip and the trunk of the femoral nerve is greater for IP catheters than for OOP catheters. Despite these findings, postoperative analgesia did not seem to differ between the 2 techniques.

Evaluation of the eZono 4000 with eZGuide for ultrasound-guided procedures

Ultrasound-guided procedures are increasingly common in a variety of acute care settings, such as the operating room, critical care unit and emergency room. However, accurate judgment of needle tip position using traditional ultrasound technology is frequently difficult, and serious injury can result from inadvertently advancing beyond or through the target. Needle navigation is a recent innovation that allows the clinician to visualize the needle position and trajectory in real time as it approaches the target. A novel ultrasound machine has recently been introduced that is portable and designed for procedural guidance. The eZono 4000™ features an innovative needle navigation technology that is simple to use and permits the use of a wide range of commercially available needles, avoiding the inconvenience and cost of proprietary equipment. This article discusses this new ultrasound machine in the context of other currently available ultrasound machines featuring needle navigation.

Evidence-based medicine for ultrasound-guided regional anesthesia

Available evidence favoring the use of ultrasound for regional anesthesia is reviewed, updated, and critically assessed. Important outcome advantages include decreased time to block onset; decreased risk of local anesthetic systemic toxicity; and, depending on the outcome definition, increased block success rates. Ultrasound guidance, peripheral nerve blocks, and central neuraxial blocks are discussed.

Use of ultrasound for lower extremity

PURPOSE OF REVIEW

To explore the recent advances in the use of ultrasound for lower extremity blocks, including approaches to the lumbar and sacral plexus blocks.

RECENT FINDINGS

Procedures of the lower extremity often require blocks of the lumbar and sacral plexuses. The use of ultrasound offers some advantages, including the possibility to directly visualize the distribution of local anesthetics.

SUMMARY

Lower extremity blocks under ultrasound guidance often require advanced skills because of the depth of target nerves. This review summarizes the recent advances in the use of ultrasound guidance over traditional techniques.

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.