Upper-Extremity Nerve Decompression Under Local Anesthesia: A Systematic Review of Methods for Reduction of Postoperative Pain and Opioid Consumption

Abstract

Background: Opioid abuse is a major health concern in North America. Data have shown an alarming increase in opioid-related deaths and complications, which has shed light on current prescription practices across many specialties, including hand surgery. To that end, we sought to conduct a focused literature review to determine the available modalities to decrease postoperative pain and opioid consumption following upper-extremity nerve decompression procedures, taking advantage of the homogeneity and inherent pain pathways of this specific patient cohort. Methods: A systematic review of the literature was conducted. Primary studies evaluating perioperative and intraoperative modalities for postoperative pain reduction and analgesic consumption following upper-extremity nerve decompression procedures under local anesthesia were included. Studies implementing modalities requiring non–hand surgeon expertise (ie, intravenous sedation), as well as studies that include non–nerve decompression procedures, were excluded. Results: A total of 1478 studies were identified, and 9 studies were included after full-text review. Six studies evaluated intraoperative and 3 studies evaluated preoperative and postoperative modalities. Successful interventions included buffered anesthetic, the use of hyaluronidase, and varying techniques and mixtures for anesthetic administration. No successful preoperative or postoperative modalities were identified. Conclusion: Despite data reporting on the dangers associated with current opioid prescription practices, evidence-based modalities to decrease postoperative pain and opioid consumption are limited in general. Several intraoperative modalities do exist, and nonopioid oral analgesics, standardized opioid protocols, and reduced postoperative prescriptions can be used. Large randomized controlled trials evaluating perioperative modalities for pain reduction are needed to further address this issue.

Introduction

In an effort to improve health care provision and patient outcomes, managing postoperative pain is currently a subject of much attention. Recent data demonstrate a substantial hazard in the form of prescription opioid overdose and dependency on a large scale, with medical, social, and economic implications.¹ Opioid misuse continues to be a health concern for Canadian physicians.^1-3 Data from recent national surveys have shown that the number of annual opioid-related deaths in Ontario, as of 2014, has increased by more than 5-folds compared with reports from 1991.⁴ This has turned the attention of researchers and clinicians to establish the efficacy of alternatives to opioids in postoperative pain management. These include—nonopioid—orally administered analgesics and local and regional anesthesia techniques.

As a specialty that offers a variety of outpatient procedures, hand surgery has not been immune to the so-called opioid epidemic. For instance, recent studies have shown an overprescription of opioids, with some demonstrating a constant or even an increase in use months after carpal tunnel release (CTR).^5,6 In the Canadian public health care system, local anesthesia is a valuable modality to hand surgeons in offering the ability to perform common hand procedures without the need for operating room time and anesthesiologists in select patients. “Minimally invasive anesthesia” in hand surgery offers the benefit of limiting the need for preoperative testing, intraoperative anesthesia monitoring, and the need for transfer to a postoperative anesthesia care unit while improving patient satisfaction.⁷ Postoperative pain control is achieved through the use of common analgesics, including opioids. Opioid consumption and postoperative pain outcomes for hand procedures under local anesthesia are therefore of interest. Upper-extremity nerve decompression procedures represent a homogeneous population that has neural-specific pain manifestations not present in other common hand procedures, including fractures and tendon decompressions. This population has, therefore, been selected for this study as a model to investigate modalities for postoperative pain reduction. The purpose of this study was to systematically review the literature reporting on modalities for postoperative pain reduction following procedures for upper-extremity nerve decompression under local anesthesia. This will in turn offer hand surgeons guidance on office-based approaches for reducing pain following common procedures such as carpal tunnel surgery and other upper-extremity nerve decompressions. Given the current state of the opioid epidemic and the continued overprescription of opioid medications following upper-extremity procedures,⁸ alternative methods for postoperative pain control are of great value.

Materials and Methods

A systematic review was carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.⁹ A search of MEDLINE via PubMed, Cochrane Collaboration Library, and Web of Science was conducted from database inception up to June 2018. Different combinations of the following key words were used: ulnar, median, radial, nerve, decompression, postoperative, and pain. The search strategy is highlighted in Figure 1. The inclusion criteria were primary studies evaluating preoperative, intraoperative, and postoperative modalities for postoperative pain reduction following procedures for upper-extremity nerve decompression under local anesthesia. Studies were excluded if interventions required non–hand surgery expertise (ie, anesthesia professionals) such as intravenous regional anesthesia (ie, bier blocks), brachial plexus blocks, and intravenous sedation. Non–nerve decompression procedures including stenosing tenosynovitis release, neurorrhaphy, and fracture fixation surgeries were excluded to allow for a more homogeneous target population. Case reports and systematic reviews were excluded in our analysis, and our search was limited to English. Other reasons for exclusion were studies with heterogeneous groups of procedures and pooled statistical analysis, the absence of specific interventions for postoperative pain reduction, and studies not evaluating postoperative pain as an end point. The inclusion and exclusion criteria are highlighted in Table 1. Primary screening was conducted based on title and abstract review. Relevant articles subsequently underwent full-text review. Screening was performed by 2 independent reviewers. The authors resolved eligibility disagreements by means of consensus. Data extraction was performed by 2 reviewers for analysis. Key data such as study design, nature of intervention, sample size, result, and study conclusions/recommendations were extracted for each study.

Figure 1.

Search strategy highlighted through the PRISMA diagram.

Note. PRISMA = Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Table 1.

Inclusion and Exclusion Criteria.

Inclusion criteria	Exclusion criteria
English language	Case reports
Human subjects	Review articles
Primary clinical studies	Intravenous regional anesthesia (Bier block)
Upper-extremity nerve decompression	Proximal upper-extremity blocks
Local anesthesia	Non–nerve decompression procedures
Postoperative pain as a primary or secondary outcome	Sedation as an independent intervention

Results

The initial search strategy yielded 1478 studies, after duplicates were removed, and subsequently, 1461 studies were excluded on the basis of title and abstract review. After full-text review, 9 studies met the eligibility criteria and were included in this analysis. Included studies were divided into 3 specific groups, based on the nature of the intervention, as follows: preoperative, intraoperative, and postoperative modalities for pain reduction following upper-extremity nerve decompression procedures. A summary of the extracted data can be found in Tables 2 and 3. In our search, all studies that met inclusion criteria have solely targeted CTR populations.

Table 2.

Studies Assessing Intraoperative Interventions for Pain Reduction.

Study	Design	Intervention	Sample size	Outcome measure	Conclusion
Ozer et al10	RCT	Buffered prilocaine vs plain prilocaine	40 (20 in treatment and 20 in control group)	Primary outcome: postoperative pain Secondary outcome: mean analgesic requirement (paracetamol) and length of analgesia	Statistically significant decrease in postoperative pain and evidence of prolonged analgesia in treatment group
Yeo et al11	RCT	Hyaluronidase with local anesthesia vs local anesthesia alone	61 (31 in treatment and 30 in control group)	Primary outcome: patient reported pain levels after injection and postoperatively	Statistically significant decrease in postoperative pain and tourniquet time in treatment group
Pressman et al12	RCT (3-phase)	Phase I: lidocaine ± adrenaline Phase II: lidocaine E vs lidocaine E + bupivacaine Phase III: lidocaine E vs ropivacaine	Phase I: 46 (23 in treatment and 23 in control group) Phase II: 37 (18 in bupivacaine and 19 in lidocaine-alone group) Phase III: 62 (32 in lidocaine group and 30 in ropivacaine group)	Primary outcome: postoperative pain Secondary outcome: analgesic consumption (Tylenol-3) during the first 10 h	Statistically significant increase in postoperative pain in lidocaine without epinephrine compared with lidocaine/adrenaline, ropivacaine, and bupivacaine groups No statistical difference between other groups
Patil et al13	RCT	Group 1: modified Gale technique Group 2: modified Altissimi and Mancini technique	Group 1: 9 patients Group 2: 11 patients	Primary outcome: intraoperative and postoperative pain Secondary outcome: analgesic consumption	Statistically significant increase in intraoperative pain in group 1 compared with group 2 Statistically significant increase in postoperative analgesic consumption in group 2 No statistical difference in postoperative pain scores
Chan et al14	RCT	Group 1: lidocaine Group 2: ropivacaine*	Group 1: 50 patients Group 2: 50 patients	Primary outcome: time to first incidence of pain, presence of pain during the first night, quality of first night’s sleep, mean pain score at 24 h, and number of days requiring analgesia	Statistically significant decrease in time to first incidence of pain in Group 1 compared with Group 2 No statistical difference for all other outcomes
Stahl et al15	RCT	Lidocaine + local infiltration of morphine vs lidocaine alone	50 (25 in treatment and 25 in control group)	Primary outcomes: surgeon rating intraoperative discomfort, intraoperative pain, and analgesic (paracetamol) consumption postoperatively	Statistically significant increase in intraoperative pain and postoperative complications in morphine group compared with controls No statistical difference for all other outcomes

Note. RCT = randomized controlled trial.

^*All injections were made subcutaneously in this study.

Table 3.

Studies Assessing Preoperative and Postoperative Interventions for Pain Reduction.

Study	Design	Intervention	Sample size	Outcome measure	Conclusion
Boriani et al16	RCT	ALA administration for 40 d postoperatively vs placebo	56 (27 in treatment and 29 in control group)	Primary outcome: postoperative electrophysiology testing Secondary outcome: pillar pain, analgesic consumption, static 2-point discrimination, and hand symptom questionnaire	No statistically significant difference for electrophysiology testing Statistically significant decrease in pillar pain in ALA group
Miller et al17	Prospective cohort study	Group 1: 20 opioids (hydrocodone oxycodone) for postoperative pain Group 2: 10 tramadol pills for postoperative pain	Group 1: 159 patients Group 2: 110 patients	Primary outcomes: number of pain medications used postoperatively and total number of days of analgesic consumption	Statistically significant decrease in total pill consumption in group 2 compared with group 1 Statistically significant increase in side effects for group 1 patients 72% of group 1 and 64% of group 2 prescriptions were not consumed
Curtin et al18	RCT	Preoperative minocycline and postoperative minocycline for 5 d vs placebo	93 (48 in treatment and 45 in control group)	Primary outcome: time to pain resolution	No statistical difference in TPR between treatment and control group

Note. ALA = alpha-lipoic acid; RCT = randomized controlled trial; TPR= time to pain resolution.

Intraoperative Interventions for Pain Reduction

Six studies were identified that evaluated intraoperative interventions for pain reduction following upper-extremity nerve decompression procedures. The results are summarized in Table 2.

Ozer et al¹⁰ studied the effects of alkalinization of local anesthetics during surgical decompression of the carpal tunnel. In this randomized controlled trial (RCT), 40 patients were assigned to receive either buffered local anesthetic (10 mL of prilocaine hydrochloride 2% buffered with 1 mL of bicarbonate 8.4%) or nonbuffered local anesthetic, with similar baseline characteristics. This study showed a statistically significant difference in the visual analog scale (VAS) scores (P = .026), with a reduction in postoperative pain for the alkalinized group. The mean analgesic requirement was also found to be reduced in the alkalinized group.

Yeo et al¹¹ studied the effects of adding hyaluronidase to local anesthetics, with the rationale that hyaluronidase would allow for the dispersal of local anesthetic between tissues, among other factors. In this RCT, 61 patients were assigned to receive either hyaluronidase (1500 IU) in addition to local anesthetic or local anesthetic alone. This study yielded a statistically significant decrease in postoperative VAS scores in the hyaluronidase group compared with controls (P = .03).

Pressman et al¹² studied the efficacies of various anesthetic solutions for surgical decompression of the carpal tunnel. In this 3-phase double-blind RCT, lidocaine, lidocaine with epinephrine (lidocaine E), ropivacaine, and bupivacaine were compared for outcomes, including postoperative pain reduction and mean analgesic consumption (Tylenol 3) during the first 10 hours following surgery. As presumed, this study revealed that postoperative pain at 2,4, and 6 hours was statistically higher in patients receiving plain lidocaine than in all other groups. The study, however, did not detect a clinically significant difference between the lidocaine E, ropivacaine, and bupivacaine groups in terms of postoperative pain scores. The main finding of this study is that plain lidocaine is inferior to lidocaine E, ropivacaine, and bupivacaine with statistically higher postoperative pain scores.

Patil et al¹³ studied the efficacy of 2 anesthetic techniques for surgical decompression of the carpal tunnel. Specifically, they compared subcutaneous infiltration alone (Gale technique) with carpal tunnel and subcutaneous infiltration (Altissimi and Mancini technique). In this RCT, 20 patients with bilateral carpal tunnel syndrome (CTS) were assigned to receive treatment with one of the 2 techniques for the initial side. The second side was operated 4 to 8 weeks later, using the alternative technique. Their study showed no statistical difference in postoperative pain scores between both groups. This study, however, showed that intraoperative pain and postoperative analgesic consumption increased for patients anesthetized with the Gale technique than with the Altissimi and Mancini approach.

Chan et al¹⁴ also studied the efficacy of short-acting lidocaine compared with long-acting ropivacaine for surgical decompression of the carpal tunnel. In this RCT, 100 patients were assigned to either the plain lidocaine (8-10 mL, 1%) or the ropivacaine group (8-10 mL, 1%), and all injections were made subcutaneously. This study showed that time to incidence of first pain was statistically shorter in the lidocaine than in the ropivacaine group (5.58, 9.17 hours, respectively, P = .035). There was, however, no statistically significant difference for all other outcomes including analgesic consumption. This study, therefore, showed that ropivacaine provides longer initial analgesia, consistent with its long-acting properties, compared with lidocaine. However, overall pain scores during the first day and analgesic consumption did not differ significantly between both groups.

Stahl et al¹⁵ studied the effects of local infiltration of morphine into the carpal tunnel during surgical decompression. In this RCT, 50 patients were assigned to receive either an infiltration of plain lidocaine morphine (2 mg) or lidocaine alone. There were no statistical differences in terms of postoperative analgesic consumption or pain scores at the time of discharge between both groups. Interestingly, this study also revealed that patients in the morphine group had a statistically higher incidence of postoperative complications compared with controls (P < .01), including fainting, hypotension, and weakness.

Preoperative and Postoperative Interventions for Pain Reduction

Two studies were identified that evaluated postoperative interventions and one study concerning preoperative interventions for postoperative pain reduction. The key findings and conclusions of these studies can be found in Table 3.

Boriani et al¹⁶ assessed the efficacy of postoperative alpha-lipoic acid (ALA) administration following surgical decompression of the carpal tunnel. In this RCT, 64 patients were assigned to receive either 800 mg of ALA for 40 days following surgery or a placebo. This study did not show a difference regarding analgesic consumption; however, the study did show a statistically significant reduction in postoperative pillar pain in the ALA compared with the control group, with a number needed to treat of 4, although associated with a large confidence interval.

Miller et al¹⁷ studied the efficacy of standard opioids (hydrocodone, codeine, and oxycodone) compared with tramadol (as a less potent, partial μ-receptor agonist, with less abuse potential) for postoperative pain control following CTR. In this prospective cohort study, 269 patients were assigned to receive either 20 standard opioid pills (hydrocodone, oxycodone, or codeine) for postoperative pain relief (159 patients) or 10 “standard” tramadol pills (110 patients). There was a statistically significant difference between both groups for overall pill consumption. The opioid and tramadol groups had mean consumptions of 4.9 pills and 3.3 pills, respectively (P = .03). Furthermore, there was a statistically significant increase in adverse effects in the opioid compared with the tramadol group, with a complication incidence of 39.7% and 13.4%, respectively (P < .001), including constipation, nausea, and drowsiness. For duration of postoperative consumption, there was no statistically significant difference between both groups. Of note, there were patients in this study who received intravenous sedation intraoperatively. Although intravenous sedation was listed as an exclusion criterion in our protocol, there were no statistical differences between both groups in terms of anesthetic type, thus controlling for any bias that sedation may have had to alter the postoperative course. Furthermore, there was a large proportion of unfilled prescriptions further attesting to the issue of overprescription of narcotics following CTR.

Curtin et al¹⁸ studied the effects of preoperative minocycline administration for postoperative pain reduction following CTR. With the aim to address persistent or chronic postsurgical pain (CPSP), the authors hypothesized that minocycline, as a microglial cell inhibitor, may influence the transition from acute to CPSP. In this RCT, 93 patients undergoing CTR were assigned to receive either 200 mg of minocycline prior to surgery or 100 mg of minocycline twice a day for 5 days following surgery or placebo given at the same intervals. There was no statistically significant difference in time to pain resolution between the treatment and control groups. It was also found that pain occurrence was common for patients receiving opioids within 6 months of surgery, highlighting the fact that patients who receive opioid therapy for other indications may be at an increased risk of developing postoperative pain. This study therefore showed that perioperative minocycline administration is not a successful modality for pain reduction following CTR surgery.

Discussion

The purpose of this study was to offer an evidence-based review for hand surgeons on the existing modalities for postoperative pain reduction following upper-extremity nerve decompression procedures, although our protocolled search yielded results limited to the CTS population. Given the rise of the opioid epidemic and the morbidity and mortality associated with consumption,¹ it is of great value to determine alternative methods for pain control. Furthermore, it has been shown that within the field of hand surgery, there is substantial opioid overprescription following common office-based procedures.^5,6

Recent large prospective studies evaluating opioid consumption patterns following common upper-extremity surgical procedures revealed consumption rates of prescribed opioids of 34%¹⁹ and 20%,²⁰ leaving a large proportion of narcotics at the disposal of patients. Most of the evidence found in this review was based on intraoperative methods for pain reduction, namely, alternative mixtures or methods of administration of local anesthetic solutions. It is of note to mention that most of the analyzed studies followed pain scores or analgesic consumption for a relatively short period postoperatively. Successful interventions included the use of buffered local anesthetic,¹⁰ hyaluronidase,¹¹ and epinephrine during anesthetic administration. These interventions were proven to reduce postoperative pain and analgesic consumption in RCTs. Regarding the use of epinephrine, as presumed, there is a significant decrease in reported postoperative pain in patients receiving anesthetic with epinephrine compared with without. For the injection itself, the use of epinephrine can be associated with a greater sting, necessitating the use of a buffer, as mentioned previously. It is therefore recommended that hand surgeons use epinephrine during upper-extremity nerve decompression procedures to reduce postoperative pain and potential consumption of narcotics, as is practiced widely. For the anesthetic technique, there exist 2 major methods for administration. The Gale technique²¹ relies on subcutaneous infiltration alone, whereas the Altissimi and Mancini technique²² uses direct infiltration into the carpal tunnel. The current review supports the use of the Altissimi and Mancini technique as it has been shown¹³ to reduce postoperative pain and analgesic consumption when compared with the Gale technique. In addition, using a long-acting local anesthetic such as ropivacaine reduces the time to incidence of pain, and there is no evidence suggesting that it reduces postoperative analgesic consumption or mean pain scores compared with short-acting lidocaine in the chosen patient cohort. Pressman et al¹² were unsuccessful in identifying a statistical difference in pain scores and analgesic consumption for patients receiving bupivacaine, ropivacaine, or lidocaine/epinephrine for undergoing CTR. There are, however, several studies showing that long-acting local anesthetic reduces postoperative pain and analgesic consumption in other surgeries.^23-26 Keramidas and Rodopoulou²³ found that for patients requiring digital nerve blocks for reconstruction of traumatic injuries, the use of ropivacaine led to a significant reduction in postoperative anesthesia and analgesic consumption compared with patients receiving lidocaine. In our search, we found no studies discussing the utility of a long-acting local anesthetic mixed with epinephrine. For studies assessing preoperative and postoperative interventions, including preemptive analgesia, for pain reduction, the literature is quite limited. This review identified trials that studied the use of postoperative ALA¹⁶ and preoperative minocycline¹⁸ but failed to show any statistical significance in reducing analgesic consumption, although ALA administration did show a significant reduction in pillar pain. Miller et al¹⁷ were, however, successful at showing that for patients undergoing CTR, tramadol is equally effective compared with standard opioids and results in fewer side effects with a lower total pill consumption rate.

One current clinical point of interest is preemptive analgesia. Ong et al²⁷ performed a meta-analysis studying the efficacy of preemptive analgesia on postoperative pain scores and analgesic consumption. Their analysis did not stratify based on procedure type but did include multiple trials covering a wide array of surgical procedures. The authors found that preemptive nonsteroidal anti-inflammatory drug administration resulted in a significant decrease in analgesic consumption and time to first rescue analgesic request but not postoperative pain scores. Within this context, there exists a relative paucity of literature on options that can be used by hand surgeons preoperatively. Gozeler et al²⁸ performed an RCT assessing the efficacy of preemptive intravenous ibuprofen on postoperative pain scores and opioid consumption for patients undergoing septorhinoplasty. The authors found that patients receiving a single dose of intravenous ibuprofen preoperatively exhibited a statistically significant reduction in postoperative pain scores and opioid consumption compared with controls. Valente²⁹ studied the analgesic effects of preincisional infiltration with bupivacaine for patients undergoing reduction mammaplasty. This RCT revealed a statistically significant reduction in postoperative pain scores and opioid consumption for patients in the bupivacaine group compared with controls.

Ilyas et al³⁰ studied alternatives to opioid use following common hand surgery procedures. In their RCT, the authors found no difference in postoperative pain scores or rate of pill consumption between patients receiving opioids and nonopioid prescriptions.³⁰ Based on these data, hand surgeons are encouraged to use oral opioid-alternative analgesics, given their increased safety profile while offering adequate postoperative pain control. Similarly, Mierisch et al³¹ assessed the use of smaller postoperative opioid prescriptions following common hand procedures. The authors found that patients receiving a smaller prescription (10 pills) had fewer leftover pills, reduced rates of prolonged consumption, and equal postoperative pain control.³¹ Mark et al³² corroborated this finding and showed that using an ultrarestrictive opioid protocol for oncologic surgeries significantly reduced consumption rates without compromising postoperative pain control.

Finally, it is essential to shed light on the lack of awareness of optimal opioid prescription practices. Stepan et al³³ studied the effects of a mandatory opioid education program and standard guidelines on prescription practices in a major academic orthopedic hospital following ambulatory upper-extremity surgery. Following the institution of these interventions, there was a 52.3% reduction in mean morphine prescription by orthopedic surgeons. Earp et al³⁴ assessed the use of an opioid prescription protocol following common upper-extremity procedures and found a significant decrease in opioid prescriptions without the need for secondary prescriptions following implementation of their consensus protocol developed by 5 orthopedic surgeons. This suggests that there is a clear educational component to this issue pointing to potential knowledge gaps that can be easily corrected through evidence-based programs for surgeons.

Conclusion

In the era of the opioid epidemic, the existing literature was searched in an effort to determine the existing preoperative, intraoperative, and postoperative modalities to reduce pain and analgesic consumption following common upper-extremity nerve decompression procedures, which can be used by surgeons in office-based procedures. Standardized opioid protocols, reduced postoperative prescriptions, and the use of nonopioid oral analgesics were identified as strategies to reduce the burden associated with the current prescription practices. For the subset of carpal tunnel patients, the utilization of a buffered, epinephrine-containing local anesthetic solution injected into the carpal tunnel in addition to the subcutaneous plane optimizes postoperative pain control. Large RCTs evaluating preoperative (eg, preemptive analgesia), intraoperative, and postoperative modalities for pain reduction are needed, in an effort to offer hand surgeons the ability to have adequate pain control without relying on standard potentially harmful opioid prescription practices.