“Usually for hip arthroscopy, the anesthesiologist performs a type of neuraxial block; in this case, a femoral nerve block or fascia iliaca block,” said Lisa Reisinger, MD, a research fellow at HSS and one of the authors of the study. “With these blocks, there is an adverse effect of quadriceps weakness leading to elevated fall risk and prolonged hospital stay.”

“PENG and LFCN are both motor-sparing blocks, but neither provide adequate pain relief for hip arthroscopy on their own,” Dr. Reisinger explained. “The purpose of this study was to evaluate whether these nerve blocks performed at the same time would lead to adequate analgesia with opioid-sparing effects and earlier discharge. While these are two commonly used techniques, it is not yet common to use them together for hip arthroscopy.”

Twenty-six patients who received only the PENG block and 86 patients who received both the PENG and LFCN blocks were matched to a control group of 112 patients who received only a neuraxial block using propensity score matching (1:1) and a caliper of 0.2, to match patients by American Society of Anesthesiologists classification, gender, and age.

The primary examined outcome was average opioid consumption in the PACU. Secondary outcomes included maximum numerical rating scale (NRS) pain score, intravenous (IV) rescue analgesia, and PACU readiness for discharge times.

The combination of a PENG block and LFCN block showed a significant reduction in average opioid consumption (more than 40% less) and earlier PACU discharge times (more than 1.7 hours earlier) compared with neuraxial alone.

There were also significantly lower severe pain scores in the PENG/LFCN group than the neuraxial alone group, which was demonstrated with the PENG/LFCN group using significantly less IV rescue analgesia and having lower maximum NRS pain scores. The PENG block alone did not demonstrate a significant pain relief benefit compared with the control group, although it did decrease the amount of time to discharge.

These results demonstrate that using both the PENG and LFCN nerve blocks may provide the best pain relief, reduce opioid use, and reduce discharge times compared with PENG block alone or neuraxial analgesia alone.

“Patients are looking for alternatives to minimize narcotic use after surgery,” said David Kim, MD, an anesthesiologist at HSS and lead author of the study. “This study offers an opioid-sparing alternative for ambulatory hip arthroscopy.”

“The next stage of research should be focusing on whether PENG/LFCN combination provides any longer-term outcome benefits to our patients, such as functional outcomes, post-discharge opioid consumption, etc.,” said Jiabin Liu, MD, an anesthesiologist and one of the authors of the study.

“Most blocks have a duration of 24 to 48 hours,” Dr. Kim added. “The next focus should be on methods for lengthening the duration beyond that.”

Reference

1. Lisa Reisinger, MD, Genewoo Hong, MD, JD, Edward Lin, MD, Sang Jo Kim, MD, Jonathan Beathe, MD, Douglas Wetmore, MD, Jiabin Liu, MD, David H Kim, MD. “Pericapsular nerve group block combined with a lateral femoral cutaneous nerve block decreases opioid consumption after hip arthroscopy: a retrospective cohort study.” Presented at: 6th World Congress on Regional Anaesthesia & Pain Medicine, September 6-9, 2023, Paris, France.

Hip arthroscopy is one of the fastest growing orthopedic procedures in the United States, and despite being minimally invasive, it is a painful procedure for which analgesia can be difficult to manage. 

“Hip arthroscopy is becoming a more popular procedure performed at free standing ambulatory surgery centers (ASC). It is important to provide optimal analgesia to help combat against the over reliance on opioids for pain relief and also to facilitate discharge and patient satisfaction,” said Dr. David Kim, anesthesiologist at HSS.

A review of the literature for opioid-sparing options has not revealed a clearly superior regimen for managing pain after this surgery. 

Because ultrasound has become more common to perform nerve blocks, novel motor-sparing blocks have been introduced, such as the PENG and LFCN. When performed separately, these blocks have been shown to provide suboptimal pain relief or to cause quadriceps weakness, if a high volume of injectate spreads to the femoral nerve. Case studies have been written on combining these nerve blocks, but this is the first prospective randomized controlled trial conducted to validate this finding.

Investigators identified 1,559 patients who had elective hip arthroscopy at HSS between January 2019 to December 2020. Of that group, 268 received both a neuraxial anesthetic and a peripheral nerve block; 86 received a PENG and an LFCN block; and 26 received a PENG block, only. A control group of 112 patients received no blocks. 

The primary outcome was total opioid consumption in the PACU. Secondary outcomes included average numeric rating scale (NRS) pain scores, maximum NRS pain scores, length of PACU stay, incidence of postoperative nausea and vomiting, and admissions to the hospital for pain management. 

Patients who received both a PENG and LFCN block required significantly less opioids in the PACU (15 mg [15,15] vs 22.5 mg [15 34]). They were also discharged earlier than the control group (2.4 hours [1.8,3.4] versus 4.1 [3.5,4.9]); 2.72 hours versus 4.42 hours, p <0.001). The combined PENG/LFCN group also used less intravenous rescue opioids than the control group (0 mg [0,0] versus 0 mg [0,2], p = 0.0099), and the highest NRS pain scores showed a significant difference in the PENG/LFCN group vs control group (7 [5,8] versus 7 [6,8], p = 0.0437). The group who received the PENG block alone did not show a significant difference in opioid reduction, but was discharged from the PACU earlier than the control group (3.35 hours [2.7,4.3]versus 4.9 hours [3.8,5.7], p = 0.0023).

These results demonstrate the combined PENG and LFCN block could be an opioid-sparing method of pain relief after hip arthroscopy. “PENG combined with a lateral femoral cutaneous nerve block decreased opioid consumption, and facilitated expedient discharges,” Dr. Kim noted.

Dr. Kim concluded “Follow up research should include a prospective randomized controlled trial comparing PENG, PENG with lateral femoral cutaneous nerve block, and no blocks, with primary focus on analgesia and motor strength.”

Reference

1. David H Kim MD, Genewoo Hong MD, JD, Edward Lin MD, Sang Jo Kim MD, Jonathan Beathe MD, Douglas Wetmore MD, Stavros Memtsoudis MD PhD MBA, Jiabin Liu MD PhD. “Pericapsular Nerve Group block combined with a lateral femoral cutaneous nerve block decreases opioid consumption after hip arthroscopy: a retrospective cohort study.” Presented at: 47th Annual Regional Anesthesiology and Acute Pain Medicine Meeting of the American Society of Regional Anesthesia and Pain Medicine (ASRA), March 31-April 2, 2021; Las Vegas, NV.

The U.S. Food & Drug Administration recently approved liposomal bupivacaine for use in interscalene nerve blocks. Liposomal bupivacaine is an extended-release formulation of bupivacaine that theoretically sustains pain relief up to 72 hours. However, there is a lack of randomized controlled trials comparing liposomal bupivacaine with placebo (saline) or with “standard” bupivacaine. 

Investigators aimed to determine whether liposomal bupivacaine actually prolongs pain relief compared with standard bupivacaine plus dexamethasone as a regional anesthetic technique. HSS has been using standard bupivacaine with perineural dexamethasone as an adjuvant in order to lengthen pain relief from nerve blocks up to 30 hours, as there are several meta-analyses and systematic reviews supporting its safe and effective use in upper extremity blockade. This study is the first randomized controlled trial comparing the two drugs as injectates in nerve blocks.

Study on prolonging nerve blocks is imperative, as “prolonging analgesia with adjuvants may be key in decreasing opioid use after surgery,” said Dr. David Kim, anesthesiologist at HSS.

The study was conducted from August 2019 to March 2021 in 112 patients undergoing ambulatory shoulder surgery. Participants were divided into two groups: 56 patients who received a mixture of 5 mL of 0.5% standard bupivacaine with 133 mg of liposomal bupivacaine; and 55 patients who received a mixture of 15 mL of 0.5% standard bupivacaine with 4 mg of dexamethasone. 

The primary outcome was average numerical rating scale (NRS) pain scores at rest over a period of 72 hours, but the researchers also examined analgesic block duration, motor and sensory resolution, opioid use, and NRS pain scale scores when resting and moving on days 1, 4 and 7 after surgery. They also examined patient satisfaction, readiness for PACU discharge, and adverse side effects related to the interscalene block. 

The results indicated that the pain score after 72 hours in the liposomal bupivacaine group was non-inferior to the bupivacaine with dexamethasone group (mean (SD), 2.4 (1.9) versus 3.4 (1.9), mean difference (95%CI), -1.1 (-1.8, -0.4), p <0.001 for noninferiority). Additionally, there was also no significant difference in the length of pain relief between the two groups. Furthermore, there was no difference in opioid consumption, readiness for PACU discharge, or adverse events. 

“Liposomal bupivacaine is noninferior to preservative-free dexamethasone when used as an adjuvant for the interscalene nerve block,” Dr. Kim noted. “Even though there was a statistically significant difference in the pain scores, the differences are unlikely to be clinically relevant. As practicing clinicians, it was important for us to investigate interventions that provide meaningful clinical differences, not to only look for statistical significance in numbers.”

Dr. Kim concluded “Follow up research should include a large prospective randomized controlled trial comparing liposomal bupivacaine and preservative-free dexamethasone on total shoulder arthroplasties.”

Reference

1. Danya A. DeMeo BS, Ejiro Gbaje MPH, Jacques T. YaDeau MD PhD, Kethy M. Jules-Elysee MD, Yi Lin MD PhD, Enrique A. Goytizolo MD, David Kim MD, Richard L Kahn MD, Stephen C. Haskins MD, David J. Mayman MD, Douglas E. Padgett MD, Thomas P. Sculco MD, Chad M. Brummett MD, Geoffrey Westrich MD. “Interscalene brachial plexus block with liposomal bupivacaine versus standard bupivacaine with perineural dexamethasone: a noninferiority trial.” Presented at: 47th Annual Regional Anesthesiology and Acute Pain Medicine Meeting of the American Society of Regional Anesthesia and Pain Medicine (ASRA), March 31-April 2, 2021; Las Vegas, NV.

The interscalene block is one of the most commonly used nerve blocks for anesthesia and analgesia in shoulder surgery, but because it commonly results in hemidiaphragmatic paralysis, it cannot be used in patients with compromised pulmonary function.

“Hemidiaphragmatic paralysis, or HDP, is when the phrenic nerve gets blocked, preventing one side of the diaphragm from working,” Dr. Kim explained. “In a healthy patient, HDP is asymptomatic and usually patients do not notice it. However, patients with underlying pulmonary disease, such as COPD, may need both sides of their diaphragm to breathe. When we inadvertently block one side of the diaphragm, they become dyspneic, sometimes leading to difficult consequences like being on a ventilator until the diaphragm recovers.”

Recent studies have examined alternatives to the interscalene block, but none had been able to reliably show effectiveness in anesthesia and analgesia without significant risk for causing HDP.

“The interscalene block and the superior trunk block are performed along the same cluster of nerves known as the brachial plexus, but at different locations,” Dr. Kim said. “Proximally, the interscalene block (ISB) is done right when the plexus exits between the scalene muscles of the neck. The ISB is in such close proximity to the phrenic nerve that it is difficult to prevent inadvertent spread to the phrenic, even when you give extraordinarily low volumes. Distally, the superior trunk block is performed at the level where a major nerve to the shoulder (suprascapular nerve) takes off. By being further away, we prevent spread to the phrenic nerve.”

“There was a case report by a group in Toronto² that performed the superior trunk block for a patient with severe pulmonary disease. They showed that by using this technique they were able to spare the diaphragm and still provide analgesia,” Dr. Kim said.

To examine the effectiveness of the superior trunk block for anesthesia in shoulder surgery, Dr. Kim and colleagues conducted a randomized controlled trial with 126 patients who underwent arthroscopic ambulatory shoulder surgery. Half of the patients received a superior trunk block (n=63) while half received an interscalene block (n=63). The primary outcomes the researchers examined were incidence of HDP (assessed via ultrasound), and worst pain score in the recovery room. Secondary outcomes measured included noninvasively measured parameters of respiratory function, opioid consumption, handgrip strength, adverse effects, and patient satisfaction.

Dr. Kim and colleagues found that the superior trunk block had a significantly lower incidence of HDP (3 of 62 [4.8%]) compared with the interscalene block (45 of 63 [71.4%]; P <.001, adjusted odds ratio 0.02 [95% CI, 0.01, 0.07]). They also found that pain relief from the superior trunk block was noninferior to the interscalene block (worst pain scores in the recovery room: (0 [0, 2] vs 0 [0, 3]; P = .951), and that patients who received the superior trunk block had lower worst pain scores on postoperative day 1.

Patients who received the superior trunk block were also more satisfied, had unaffected respiratory parameters, and had a lower incidence of hoarseness. No difference was found between the groups in handgrip strength or opioid consumption.

“By using ultrasound, we are able to inject local anesthetic at a precise location that effectively blocks the brachial plexus but also spares the phrenic nerve,” Dr. Kim said. “This opens the possibility of improving our armamentarium of regional blocks. Goals are shifting to provide better blocks that are not only profound opioid-sparing analgesics but also spare motor strength. We are improving upon our current understanding of the anatomy and targeting the nerves we want to block.”

Dr. Kim and colleagues concluded that because the superior trunk block provided noninferior surgical anesthesia and had a much lower incidence of HDP, the superior trunk block may be an alternative to the traditional interscalene block for shoulder surgery.

“Regional anesthesia continues to evolve. With new innovations and progress, we have improved patient care and satisfaction by providing blocks that effectively provide pain relief while sparing motor function. With the superior trunk block, our patients had profound surgical anesthesia and analgesia, took minimal amounts of opioids, had sparing of the diaphragm, and was able to move their hands. This was a certain improvement on our gold standard, the interscalene block,” Dr. Kim concluded.

References

1. Kim DH, Lin Y, Beathe JC, Liu J, Oxendine JA, Haskins SC, Ho MC, Wetmore DS, Allen AA, Wilson L, Garnett C, Memtsoudis SG. Superior trunk block: A phrenic-sparing alternative to the interscalene block: a randomized controlled trial. Anesthesiology. 2019. doi: 10.1097/ALN.0000000000002841

2. Burkett-St. Laurent D, Chan V, Chin KJ. Refining the ultrasound-guided interscalene brachial plexus block: the superior trunk approach. Can J Anesth. 2014;61(12):1098-1102.

The results were presented at the World Congress on Regional Anesthesia & Pain Medicine.

"The addition of [interspace between the popliteal artery and capsule of the posterior knee block] IPACK and [adductor canal block] ACB are shown to be an extremely valuable modality to add to a multimodal pathway," said Dr. Kim.

Read the full article at healio.com [registration required].

Additional Coverage:

• Doctor's Lounge: Less Pain Post TKA With Addition of Peripheral Nerve Blocks
• Rheumatology Advisor: Less Pain After TKA With Addition of Peripheral Nerve Blocks

The rate of ambulatory surgery is expected to grow 51 percent by 2026, and to meet this increase in volume ambulatory centers are looking for ways to optimize post-operative pain management in the setting of increasingly common fast-track strategies. To that end, many surgeons use periarticular injections (PAIs) for total knee arthroplasties (TKAs). PAIs help reduce postoperative pain, but there are opportunities to further improve patient care and reduce opioid consumption, explained Jonathan Beathe, MD, co-author, and anesthesiologist within the Department of Anesthesiology, Critical Care & Pain Management at HSS.

"In order for patients to start moving after TKA earlier while using less opioids, anesthesiologists and surgeons should collaborate to use different methods of analgesia," explained Dr. Beathe. "This includes adding nerve blocks to periarticular injections. These nerve blocks target the sensory nerves that spare motor function and facilitate early ambulation and rehabilitation, a major goal for patients undergoing TKA."

A team of investigators examined whether adding motor-sparing peripheral nerve blocks (MSBs) to a PAI would lower pain in the postoperative period compared to PAI alone. The MSBs used in the study were the adductor canal block (ACB) and the interspace between the popliteal artery and capsule of the posterior knee (IPACK) block. 

The investigators randomly assigned 86 patients undergoing a TKA to receive either a PAI (n=43), or an IPACK and ACB with modified PAI injection (n=43). To determine the efficacy of these combined anesthetic approaches, the researchers compared post-operative pain levels, numeric rating scale (NRS) pain scores, pain outcomes, and opioid consumption.

On post-operative day 1, the group that received a combination of IPACK block and ACB with PAI reported lower NRS pain scores compared with the group who received PAI only (1.7 versus 5). There was a significant difference in pain scores on ambulation on post-operative day 0 (1.7 versus 5.2) and on post-operative day 3 (4.5 versus 5.5). The group who received the IPACK and ACB with PAI intervention also reported lower pain scores after physical therapy on post-operative day 0 and 1 (1.9) compared with the PAI group (1.4).

"Patients who received an IPACK and ACB in addition to a PAI were overwhelmingly more satisfied," said David Kim, MD, anesthesiologist and principal investigator of the study. "Those who received the combination intervention reported less interference from pain when walking, less opioid consumption in the Post-Anesthesia Care Unit (PACU), less intravenous patient-controlled analgesia and less intravenous opioids compared to the patients who received PAI alone."

While there was no difference in hospital length of stay, more patients in the IPACK/ACB group were discharged on post-operative 0 and post-operative day 1 (5 percent and 19 percent, respectively) compared to those who received PAI only (0 and 16 percent, respectively).

"Anesthesiologists and surgeons should consider adding the IPACK block and ACB to a modified PAI to manage pain control in patients undergoing TKA more effectively," said Dr. Kim. "This collaborative anesthetic approach should be considered as part of a multimodal analgesic pathway for TKAs."

Reference

Kim, David MD, Lin Yi MD PhD, Beathe, Jonathan MD, Goytizolo, Enrique MD, Oxendine, Joseph MD, YaDeau, Jacques MD PhD, Maalouf, Daniel MD MPH, Garnett, Christopher BA, Ranawat, Amar MD, Su, Edwin MD, Mayman, David MD, Westrich, Geoffrey MD, Alexiades, Michael MD, Memtsoudis, Savros, MD PhD. "The addition of ACB and IPACK to PAI enhances postoperative pain control in TKA: A randomized controlled trial." Poster presented at: 2018 World Congress on Regional Anesthesia and Pain Medicine; April 19-21, 2017; New York, NY.