Suture-method versus Through-the-needle Catheters for Continuous Popliteal-sciatic Nerve Blocks

Continuous peripheral nerve blocks for analgesia following painful ambulatory surgery: a review with focus on recent developments in infusion technology

PURPOSE OF REVIEW

Continuous peripheral nerve blocks (cPNB) decrease pain scores and opioid consumption while improving patient satisfaction following ambulatory surgery. This review focuses on the history and evolution of ambulatory cPNBs, recent developments in infusion technology that may prolong the duration of analgesia, optimal choice of cPNB for various surgical procedures, and novel analgesic modalities that may prove to be alternatives or supplements to cPNBs.

RECENT FINDINGS

The primary factor limiting the duration of an ambulatory cPNB is the size of the local anesthetic reservoir. Recent evidence suggests the use of automated boluses, as opposed to continuous infusions, may decrease the rate of consumption of local anesthetic and, thereby, prolong the duration of analgesia. Utilizing a long-acting local anesthetic (e.g. ropivacaine) for initial block placement and an infusion start-delay timer may further increase this duration.

SUMMARY

Patients undergoing painful ambulatory surgery are likely to have less pain and require fewer opioid analgesics when receiving a cPNB for postoperative analgesia. Advances in electronic pumps used for cPNBs may increase the duration of these benefits.

Impact of self-coiling catheters for continuous popliteal sciatic block on postoperative pain level and dislocation rate: a randomized controlled trial

Background

Dislocation of catheters within the tissue is a challenge in continuous regional anesthesia. A novel self-coiling catheter design is available and has demonstrated a lower dislocation rate in a cadaver model. The dislocation rate and effect on postoperative pain of these catheters in vivo has yet to be determined and were the subjects of this investigation.

Methods

After ethics committee approval 140 patients undergoing elective distal lower limb surgery were enrolled in this prospective randomized controlled trial. Preoperatively, patients were randomly assigned and received either the conventional (n = 70) or self-coiling catheter (n = 70) for ultrasound-guided popliteal sciatic nerve block in short axis view and by the in-plane approach from lateral to medial. The primary outcome was pain intensity after surgery and on the following three postoperative days. Secondary outcomes investigated were dislocation rate in situ determined by sonography, catheter movement visible from outside, opioid consumption as well as leakage at the puncture site.

Results

All catheters were successfully inserted. The study population of self-coiling catheters had significantly lower mean numeric rating scale values than the reference cohort on the first (p = 0.01) and second postoperative days (p < 0.01). Sonographic evaluation demonstrated, 42 standard catheters (60%) and 10 self-coiling catheters (14.3%) were dislocated in situ within the first three postoperative days. The externally visible movement of the catheters at insertion site did not differ significantly between groups through the third postoperative day. The opioid consumption was significantly lower in the self-coiling catheter group on the day of surgery and on the second and third postoperative days (p = 0.04, p = 0.03 and p = 0.04, respectively).

Conclusion

The self-coiling catheter offers a better postoperative pain control and a lower dislocation rate within the tissue when blocking the popliteal sciatic nerve compared to a conventional catheter. Further trials in large patient cohorts are warranted to investigate the potential beneficial effects of self-coiling catheters for other localisations and other application techniques.

Trial registration

The trial was registered at German Clinical Trials Register (DRKS) on 08/04/2020 (DRKS00020938, retrospectively registered).

Automated Boluses and Delayed-Start Timers Prolong Perineural Local Anesthetic Infusions and Analgesia Following Ankle and Wrist Orthopedic Surgery: A Case-Control Series

Background

Continuous peripheral nerve blocks can be administered as continuous infusion, patient-controlled boluses, automated boluses, or a combination of these modalities.

Material/Methods

Ten patients undergoing either ankle (5) or distal radius (5) open reduction and internal fixation received single-injection ropivacaine sciatic nerve block or infraclavicular brachial plexus block and catheter. Infusion pumps were set to begin administering additional ropivacaine 6 h following the initial block as automated boluses supplemented with patient-controlled boluses.

Results

Patients had similar pain scores when compared to previously published controls; however, local anesthetic consumption was lower in the patients, resulting in increased infusion and analgesia duration by 1 or more days in each group.

Conclusions

For infraclavicular and popliteal sciatic catheters, automated boluses may provide a longer duration of analgesia than continuous infusions following painful hand and ankle surgeries, respectively.

Incidence of Suture-Method Catheter Dislocation with Femoral Nerve Block and Femoral Triangle Block after Total Knee Arthroplasty

Catheter dislocation with continuous peripheral nerve blocks represents a major problem in clinical settings. There is a range of factors affecting the incidence of catheter dislocation, including catheter type. This study aimed to assess the incidence of suture-method catheter (SMC) dislocation 24 h after total knee arthroplasty (TKA), with continuous femoral nerve block (CFNB) and continuous femoral triangle block (CFTB), respectively. In the prospective randomized trial, 40 patients qualified for TKA with SMC and were divided into two groups, those who received CFNB (Group 1, n = 20) and those who received CFTB (Group 2, n = 20). After 24 h, the degree of catheter displacement (cm), pain intensity (NRS) and opioid consumption (mg) was assessed. The catheter dislocation rates were found to be 15% in Group 1 versus 5% in Group 2, with the catheter dislocated by 0.83 cm (SD = ±0.87) and 0.43 cm (SD = ±0.67), respectively. There were no differences in NRS score (p = 0.86) or opioid consumption (p = 0.16) between the groups. In each case, a displaced catheter was successfully repositioned by pulling, which clinically resulted in a lower NRS score. The results of the study suggest that CFTB with SMC may be used after TKA with a good effect, as it is associated with low catheter dislocation rates and an adequate analgesic effect.

Incidence and effects of postoperative migration of interscalene catheter tips placed using ultrasound-guided anterior and posterior approaches

BACKGROUND

Continuous interscalene brachial plexus block (CISB) provides analgesia after shoulder surgery. However, even a catheter securely fixed at the insertion site may be susceptible to migration, precluding the block from working consistently. We examined to see if catheter tip migration would occur with no catheter-at-skin change after anterior and posterior approaches to CISB in patients undergoing shoulder surgery, and compared the incidence rate and pain scores between approaches and between catheters with and without tip migration, respectively.

METHODS

Patients were randomly assigned to receive CISB using either anterior or posterior approach. Catheter tip was observed using a cross-sectional view. The rates of catheter tip migration with no catheter-at-skin change at 24 h after the two approaches were calculated and compared, and pain scores were compared between catheters with and without tip migration after each approach.

RESULTS

Fifty-four patients were analyzed. Catheter tip migration occurred at 24 h at a similar rate after both approaches (anterior approach 40.7% versus posterior approach 33.3%, p = 0.78). Worst pain score was significantly higher for 24 h in patients whose catheter tip had migrated as compared with those whose catheter had not migrated after anterior (median [IQR] 53 [42-73] versus 18 [0-50], p = 0.003) and posterior approaches (median [IQR] 63 [57-81] versus 29 [3-47], p < 0.0001).

CONCLUSION

In patients undergoing shoulder surgery, an interscalene catheter tip can migrate after both anterior and posterior approaches at a similar rate, even if the catheter insertion length is not changed. The tip migration does decrease the analgesic effect of CISB.