Adductor Canal Versus Femoral Nerve Block after Anterior Cruciate Ligament Reconstruction: A Systematic Review of Level I Randomized Controlled Trials Comparing Early Postoperative Pain, Opioid Requirements, and Quadriceps Strength

The Addition of a Pericapsular Nerve Group Block for Postoperative Pain Control Does Not Result in Less Narcotic Use After Hip Arthroscopy: A Systematic Review

Purpose

To perform a systematic review of clinical studies evaluating the pericapsular nerve group (PENG) block in patients undergoing hip arthroscopy.

Methods

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify comparative studies of patients undergoing the PENG block before hip arthroscopy. The search phrase used was hip arthroscopy pericapsular nerve block. Patients were evaluated based on analgesic consumption, time to discharge from the postanesthesia care unit (PACU), and pain scores (Numeric Rating Scale and visual analog scale). The Modified Coleman Methodology Score was used to evaluate study methodology quality.

Results

Five studies (2 Level I, 3 Level III) met inclusion criteria. The 5 studies included the following comparison groups: 0.9% normal saline injection, general anesthesia alone, and general anesthesia with intraoperative pericapsular bupivacaine injection. The 2 randomized controlled trials included in this review reported no significant difference between groups regarding opioid consumption. One of these did not find any statistically significant differences in their secondary outcomes either, including patient satisfaction with analgesia, opioid-related adverse events, or persistent opioid use at 1 week. However, the other 3 studies found significantly lower opioid consumption in patients receiving the PENG block versus the control group intraoperatively, in the PACU, and/or postoperatively. Four studies reported significantly lower pain levels in the PENG block group compared with the control groups, measured differently in each study: 24 hours postoperatively, initial pain score in the PACU, mean score in the PACU, and highest score in the PACU. None of the studies found significantly worse outcomes in the PENG block group compared to the comparison group.

Conclusions

Systematic review of randomized controlled trials shows that patients undergoing hip arthroscopy who receive a PENG block do not consume fewer opioids for postoperative pain control than patients who do not receive the block.

Level of Evidence

Level III, systematic review of Level I-III studies.

Prospective Comparison of Postoperative Pain and Opioid Consumption Between Primary Repair and Reconstruction of the Anterior Cruciate Ligament

Background

Anterior cruciate ligament (ACL) reconstruction (ACLR) is associated with postoperative pain and necessitates using perioperative nerve blocks and multimodal analgesic plans.

Purpose

To assess postoperative pain and daily opioid use after ACL repair versus ACLR and to assess whether ACL repair could be performed successfully without using long-acting nerve blocks.

Study Design

Cohort study; Level of evidence, 2.

Methods

All eligible patients who underwent ACL surgery between 2019 and 2022 were prospectively enrolled. Patients were treated with primary repair if proximal tears with sufficient tissue quality were present; otherwise, they underwent single-bundle ACLR with either hamstring tendon or quadriceps tendon autograft. The patients were divided into 3 groups: ACLR with adductor canal nerve block (up to 20 mL of 0.25% bupivacaine with 2 mg dexamethasone), primary repair with nerve block, and primary repair without nerve block. Pain visual analog scale and number of opioids used were recorded during the first 14 postoperative days (PODs). Furthermore, patients completed the Quality of Recovery-15 (QoR-15) survey, and range of motion was assessed. Group differences were compared using Mann-Whitney U test and chi-square test.

Results

Seventy-eight patients were included: 30 (39%) underwent ACLR, 19 (24%) ACL repair with nerve block, and 29 (37%) ACL repair without nerve block. Overall, the ACL repair group used significantly fewer opioids than the ACLR group on POD 1 (1 vs 3, P = .027) and POD 2 (1 vs 3, P = .014) while also using fewer opioids in total (3 vs 8, P = .038). This difference was even more marked when only analyzing those patients who received postoperative nerve blocks (1 vs 8, P = .029). Repair patients had significantly higher QoR-15 scores throughout the first postoperative week, and they had greater range of motion (all P < .05). There were no significant differences in pain scores, opioid usage, or QoR-15 scores between patients who underwent repair with versus without nerve block.

Conclusion

The ACL repair group experienced less postoperative pain during the first 2 weeks after surgery and used significantly fewer opioids than the ACLR group. Furthermore, they had improved knee function and higher recovery quality than patients who underwent ACLR during the initial postoperative period. Postoperative nerve blocks may not be necessary after ACL repair.

Femoral Nerve Block and Local Instillation Analgesia Associated With More Reliable Efficacy in Regional Anesthesia Interventions Within 24 Hours Following Anterior Cruciate Ligament Reconstruction: A Network Meta-analysis

PURPOSE

To assess the relative effectiveness of different regional anesthetic techniques (peripheral nerve blocks, local instillation analgesia, including intra-articular, subcutaneous, and periarticular infiltration) in patients undergoing anterior cruciate ligament reconstruction (ACLR).

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched from their inception to December 31, 2020. The search was supplemented by manual review of relevant reference lists. Randomized controlled trials of participants after ACLR that compared regional anesthesia interventions were selected. The 2 coprimary outcomes were (1) rest pain scores and (2) cumulative oral morphine equivalent consumption on day 1 (24 hours) post-ACLR. Data were pooled using a Bayesian framework.

RESULTS

Of 759 records identified, 46 trials were eligible, evaluating 9 interventions in 3,171 patients. Local instillation analgesia (LIA), including intra-articular, subcutaneous, and periarticular infiltration, had significant improvement in pain relief as compared with placebo (-0.91; 95% CrI -1.45 to -0.37). Femoral nerve block (FNB) also showed significant effects in relieving pain as compared with placebo (-0.70; 95% 95% credible interval [CrI] -1.28 to -0.12). Compared with placebo, a significant reduction in opioid consumption was found in LIA (mean difference -13.29 mg; 95% CrI -21.77 to -4.91) and FNB (mean difference -13.97 mg; 95% CrI -24.71 to -3.04). Femoral and sciatic nerve block showed the greatest ranking for pain relief and opioid consumption without significant evidence (P > .05) to support superiority in comparison with placebo, respectively.

CONCLUSIONS

Our meta-analysis shows that FNB and LIA can significantly diminish postoperative pain and reduce opioid consumption following ACLR compared with placebo in the setting of regional anesthesia, and femoral and sciatic nerve block may be the number 1 top-ranked analgesic technique despite high uncertainty.

LEVEL OF EVIDENCE

I, Systematic review of Level I studies.

Improved Pain and Perioperative Outcomes After Hip Arthroscopy With the Pericapsular Nerve Group Block

PURPOSE

To compare early postoperative pain in patients undergoing hip arthroscopy with versus without the pericapsular nerve group (PENG) block.

METHODS

A retrospective chart review of prospectively collected data was performed to identify patients who underwent hip arthroscopy at a single institution between May 2019 and October 2021. Patients were included if they received general anesthesia and were opioid naive. Patients who received the PENG block were compared with patients who did not. Opioid, benzodiazepine, and antiemetic medication administration was recorded both intraoperatively and for the duration of the patient's stay in the postanesthesia care unit (PACU). Opioids administered were converted to morphine milligram equivalents (MMEs). Pain was assessed with a visual analog scale. Time to discharge (in minutes) and complications were recorded.

RESULTS

A total of 53 patients were identified for inclusion, of whom 28 received the PENG block and 25 did not. Opioid consumption was significantly lower in the PENG block group both intraoperatively (16.9 ± 14.1 MMEs vs 40.6 ± 18.3 MMEs, P < .001) and in the PACU (14.4 ± 11.4 MMEs vs 31.2 ± 20.1 MMEs, P < .001). The highest recorded PACU pain score was significantly greater in the no-PENG block group (7.0 ± 1.9 vs 5.3 ± 2.1, P = .004). Within the PENG block group, fewer patients required antiemetics (0 vs 4, P = .043). There was a greater time to discharge in the no-PENG block group (161 ± 50 minutes vs 129 ± 34 minutes, P = .008). No complications, including postoperative falls, were noted in either group.

CONCLUSIONS

The PENG block improves perioperative outcomes by decreasing pain, opioid consumption, time to discharge, antiemetic requirements, and benzodiazepine requirements after hip arthroscopy.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic trial.

Motor-Sparing Effect of Adductor Canal Block for Knee Analgesia: An Updated Review and a Subgroup Analysis of Randomized Controlled Trials Based on a Corrected Classification System

OBJECTIVE

Discrepancies in the definition of adductor canal block (ACB) lead to inconsistent results. To investigate the actual analgesic and motor-sparing effects of ACB by anatomically defining femoral triangle block (FTB), proximal ACB (p-ACB), and distal ACB (d-ACB), we re-classified the previously claimed ACB approaches according to the ultrasound findings or descriptions in the corresponding published articles. A meta-analysis with subsequent subgroup analyses based on these corrected results was performed to examine the true impact of ACB on its analgesic effect and motor function (quadriceps muscle strength or mobilization ability). An optimal ACB technique was also suggested based on an updated review of evidence and ultrasound anatomy.

MATERIALS AND METHODS

We systematically searched studies describing the use of ACB for knee surgery. Cochrane Library, PubMed, Web of Science, and Embase were searched with the exclusion of non-English articles from inception to 28 February 2022. The motor-sparing and analgesic aspects in true ACB were evaluated using meta-analyses with subsequent subgroup analyses according to the corrected classification system.

RESULTS

The meta-analysis includes 19 randomized controlled trials. Compared with the femoral nerve block group, the quadriceps muscle strength (standardized mean difference (SMD) = 0.33, 95%-CI [0.01; 0.65]) and mobilization ability (SMD = -22.44, 95%-CI [-35.37; -9.51]) are more preserved in the mixed ACB group at 24 h after knee surgery. Compared with the true ACB group, the FTB group (SMD = 5.59, 95%-CI [3.44; 8.46]) has a significantly decreased mobilization ability at 24 h after knee surgery.

CONCLUSION

By using the corrected classification system, we proved the motor-sparing effect of true ACB compared to FTB. According to the updated ultrasound anatomy, we suggested proximal ACB to be the analgesic technique of choice for knee surgery. Although a single-shot ACB is limited in duration, it remains the candidate of the analgesic standard for knee surgery on postoperative day 1 or 2 because it induces analgesia with less motor involvement in the era of multimodal analgesia. Furthermore, data from the corrected classification system may provide the basis for future research.

A Practical Guide to Lower Extremity Nerve Blocks for the Sports Medicine Surgeon

BACKGROUND

Peripheral nerve blocks (PNBs) are vital in the administration of surgical analgesia and have grown in popularity for use in lower extremity arthroscopic procedures because of their capacity to safely and effectively control pain. The number and specificity of PNBs, however, have made choosing the best option for a procedure nebulous for orthopaedic surgeons.

PURPOSE

To present a narrative literature review of the PNBs available for arthroscopic hip and knee procedures that is adapted to an audience of orthopaedic surgeons.

STUDY DESIGN

Narrative literature review.

METHODS

A combination of the names of various lower extremity PNBs AND "hip arthroscopy" OR "knee arthroscopy" was used to search the English medical literature including PubMed, Cochrane Library, ScienceDirect, Embase, and Scopus. Placement technique, specificity of blockade, efficacy, and complications were assessed. Searches were performed through May 2, 2021.

RESULTS

A total of 157 studies were included in this review of lower extremity PNBs. Femoral nerve, lumbar plexus, sciatic nerve, and fascia iliaca compartment blocks were most commonly used in arthroscopic hip surgery, while femoral nerve, 3-in-1, and adductor canal blocks were preferred for arthroscopic knee surgery. Each block demonstrated a significant benefit (P > .05) in ≥1 of the following outcomes: intraoperative morphine, pain scores, nausea, and/or opioid consumption. Combination blocks including the lateral femoral cutaneous nerve block, obturator nerve block, quadratus lumborum block, and L1 and L2 paravertebral block have also been described. Complication rates ranged from 0% to 4.8% in those administered with ultrasound guidance. The most commonly reported complications included muscular weakness, postoperative falls, neuropathy, intravascular and intraneural injections, and hematomas.

CONCLUSION

When administered properly, PNBs were a safe and effective adjuvant method of pain control with a significant potential to limit postoperative narcotic use. While blockade choice varies by surgeon preference and procedure, all PNBs should be administered with ultrasound guidance, and vigilant protocols for the risk of postoperative falls should be exercised in patients who receive them.

Combined femoral-obturator-sciatic nerve block has superior postoperative pain score and earlier ambulation as compared to spinal anaesthesia for arthroscopic anterior cruciate ligament reconstruction

PURPOSE

Peripheral nerve blocks can be a suitable alternative to central neuraxial blockage, as the sole anaesthetic agent for better early postoperative outcomes, decreased hospital stay and earlier mobilisation after anterior cruciate ligament reconstruction (ACLR) surgery. The purpose of this study was to compare consciousness during the procedure, pain during early postoperative period (< 7 days), and perioperative outcomes following ACLR using combined sciatic, femoral, and obturator nerve blocks compared to the spinal anaesthesia.

METHODS

This was a prospective case-control study including patients between 18 and 55 years of age, with anterior cruciate ligament (ACL) injury confirmed clinically and radiologically and undergoing ACLR. Patients were allocated in the two groups alternatively, group 1 included patients who received combined nerve blocks, and group 2 included patients who received spinal anaesthesia for the surgery. The sensory effect, motor effect, adequacy of anaesthesia, perioperative analgesic use, duration of stay, postoperative pain (visual analogue scale 0-10 cm) and functional outcomes were noted.

RESULTS

There were 60 patients in each group. A total of seven patients in group 1 (11%) and two patients in group 2 (3%) needed conversion to general anaesthesia (n.s.). In group 1, out of 53 patients who underwent surgery, 26 patients had no perception of surgery in the joint, 17 patients had perception of manipulation of the knee joint, 4 patients had sense of touch, and 6 patients had sensation of pain in the knee (VAS scale less than 3). In group 2, out of 58 patients, 42 patients had no perception of surgery, 12 had a perception of manipulation of the knee joint, 2 had sense of touch, and 2 had sensation of pain in the knee. Blockage of sensory effect was significantly better in group 2 (p = 0.0001). However, the motor effect was comparable between the two groups (n.s.). Group 1 had significantly better pain scores 6, 12, and 18 h after the surgery. Moreover, patients in group 1 also had faster ambulation (mean difference of 5.5 h, p = 0.0001) and reduced hospital stay (mean difference of 8.4 h, p = 0.0001).

CONCLUSION

Combined sciatic, femoral, and adductor canal block is an effective sole anaesthetic modality for ACLR. The sensory effect was inferior when compared to spinal anaesthesia but sufficient for the procedure without the need for supplementation with any other anaesthetic modality. Patients receiving this combined nerve block had lesser early postoperative pain scores, earlier ambulation, and shorter hospital stay as compared to the spinal anaesthesia.

LEVEL OF EVIDENCE

Level 3.

Anterior cruciate ligament reconstruction with ultrasound-guided femoral nerve block does not adversely affect knee extensor strength beyond that seen with intravenous patient-controlled analgesia at 3 and 6 months postoperatively

BACKGROUND

This study aimed to investigate the effect of anterior cruciate ligament (ACL) reconstruction with an ultrasound-guided femoral nerve block (FNB) on knee extensor strength weakness 3 and 6 months, and graft rupture in the 1 year following ACL reconstruction.

METHODS

One hundred and seven patients who underwent ACL reconstruction were included in this retrospective study. The patients were divided into two groups stratified by the method of postoperative pain management. The FNB group included 66 patients, and there were 41 patients in the intravenous patient-controlled analgesia (iv-PCA) group. The isokinetic peak torque of knee flexor and extensor was measured preoperative, 3 and 6 months after ACL reconstruction. Muscle strength measurements were performed using the BIODEX dynamometer at a velocity of 60°/s and 180°/s. Peak torque of knee extensor and flexor strength, estimated pre-injury capacity (EPIC), body weight ratio (BW), and graft rupture incidence were compared between the two groups.

RESULTS

There were no statistically significant differences in the knee extensor and flexor strength for all items at 3 and 6 months after ACL reconstruction. There was also not a statistically significant difference in the graft rupture incidence between the two groups: FNB group was two patients, 3.0% vs. iv-PCA group was one patient, 2.4% (p = 0.86).

CONCLUSION

ACL reconstruction with ultrasound-guided FNB does not affect knee extensor strength at 6 months, nor graft rupture at 1 year postoperatively.

Fascia Iliaca Block for Postoperative Pain Control After Hip Arthroscopy: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Various analgesic modalities have been used to improve postoperative pain in patients undergoing hip arthroscopy.

PURPOSE

To systematically review the literature to compare the efficacy of the fascia iliaca block (FIB) with that of other analgesic modalities after hip arthroscopy in terms of postoperative pain scores and analgesic consumption.

STUDY DESIGN

Systematic review.

METHODS

A systematic review was performed by searching PubMed, the Cochrane Library, and Embase up to April 2020 to identify randomized controlled trials that compared postoperative pain and analgesic consumption in patients after hip arthroscopy with FIB versus other pain control modalities. The search phrase used was "hip arthroscopy fascia iliaca randomized." Patients were evaluated based on postoperative pain scores and total postoperative analgesic consumption.

RESULTS

Five studies (3 level 1, 2 level 2) were identified that met inclusion criteria, including 157 patients undergoing hip arthroscopy with FIB (mean age, 38.3 years; 44.6% men) and 159 patients among the following comparison groups: lumbar plexus block (LPB), intra-articular ropivacaine (IAR), local anesthetic infiltration (LAI), saline placebo, and a no-block control group (overall mean age, 36.2 years; 36.5% men). No significant differences in pain scores were reported in the postanesthesia care unit (PACU) between the FIB and LPB (3.4 vs 2.9; P = .054), IAR (7.7 vs 7.9; P = .72), control group (no FIB: 4.1 vs 3.8; P = .76); or saline placebo (difference, -0.2 [95% CI, -1.1 to 0.7]). One study reported significantly higher pain scores at 1 hour postoperation in the FIB group compared with the LAI group (5.5 vs 3.4; P = .02). Another study reported significantly greater total analgesic consumption (in morphine equivalent dosing) in the PACU among the FIB group compared with the LPB group (20.8 vs 17.0; P = .02). No significant differences were observed in total PACU analgesic consumption between FIB and other analgesic modalities.

CONCLUSION

In patients undergoing hip arthroscopy, the FIB does not appear to demonstrate superiority to other forms of analgesics in the immediate postoperative period. Therefore, it is not recommended as a routine form of pain control for these procedures.

Managing Perioperative Pain After Anterior Cruciate Ligament (ACL) Reconstruction: Perspectives from a Sports Medicine Surgeon

Anterior cruciate ligament reconstructions (ACLR) are a relatively common procedure in orthopedic sports medicine with an estimated 130,000 arthroscopic operations performed annually. Most procedures are carried out on an outpatient basis, and though success rates of ACLR are as high as 95%, pain remains the most common postoperative complication delaying patient discharge, and thereby increasing the costs associated with patient care. Despite the success and relative frequency of ACLR surgery, optimal and widely accepted strategies and regimens for controlling perioperative pain are not well established. In recent years, the paradigm of pain control has shifted from exclusively utilizing opiates and opioid medications in the acute postoperative period to employing other agents and techniques including nerve blocks, intra-articular and periarticular injections of local anesthetic agents, NSAIDs, and less commonly, ketamine, tranexamic acid (TXA), sedatives, gabapentin, and corticosteroids. More often, these agents are now used in combination and in synergy with one another as part of a multimodal approach to pain management in ACLR, with the goal of reducing postoperative pain, opioid consumption, and the incidence of delayed hospital discharge. The purpose of this review is to consolidate current literature on various agents involved in the management of postoperative pain following ACLR, including the role of classically used opiate and opioid medications, as well as to describe other drugs currently utilized in practice either individually or in conjunction with other agents as part of a multimodal regimen in pain management in ACLR.

Fascial plane blocks: a narrative review of the literature

Fascial plane blocks (FPBs) are increasingly numerous and are often touted as effective solutions to many perioperative challenges facing anesthesiologists. As 'new' FPBs are being described, questions regarding their effectiveness remain unanswered as appropriate studies are lacking and publications are often limited to case discussions or technical reports. It is often unclear if newly named FPBs truly represent a novel intervention with new indications, or if these new publications describe mere ultrasound facilitated modifications of existing techniques. Here, we present broad concepts and potential mechanisms of FPB. In addition, we discuss major FPBs of (1) the extremities (2) the posterior torso and (3) the anterior torso. The characteristics, indications and a brief summary of the literature on these blocks is included. Finally, we provide an estimate of the overall level of evidence currently supporting individual approaches as FPBs continue to rapidly evolve.

Rupture, reconstruction, and rehabilitation: A multi-disciplinary review of mechanisms for central nervous system adaptations following anterior cruciate ligament injury

BACKGROUND

Despite surgical reconstruction and extensive rehabilitation, persistent quadriceps inhibition, gait asymmetry, and functional impairment remain prevalent in patients after anterior cruciate ligament (ACL) injury. A combination of reports have suggested underlying central nervous system adaptations in those after injury govern long-term neuromuscular impairments. The classic assumption has been to attribute neurophysiologic deficits to components of injury, but other factors across the continuum of care (e.g. surgery, perioperative analgesia, and rehabilitative strategies) have been largely overlooked.

OBJECTIVE

This review provides a multidisciplinary perspective to 1) provide a narrative review of studies reporting neuroplasticity following ACL injury in order to inform clinicians of the current state of literature and 2) provide a mechanistic framework of neurophysiologic deficits with potential clinical implications across all phases of injury and recovery (injury, surgery, and rehabilitation) RESULTS: Studies using a variety of neurophysiologic modalities have demonstrated peripheral and central nervous system adaptations in those with prior ACL injury. Longitudinal investigations suggest neurophysiologic changes at spinal-reflexive and corticospinal pathways follow a unique timecourse across injury, surgery, and rehabilitation.

CONCLUSION

Clinicians should consider the unique injury, surgery, anesthesia, and rehabilitation on central nervous system adaptations. Therapeutic strategies across the continuum of care may be beneficial to mitigate maladaptive neuroplasticity in those after ACL injury.

Return to Driving After Anterior Cruciate Ligament Reconstruction: A Systematic Review

Background

Guidelines for return to driving after anterior cruciate ligament reconstruction (ACLR) have not been established.

Purpose

To review the literature pertaining to driving after ACLR and provide evidence-based guidelines to aid clinicians in counseling patients about driving after ACLR.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Two independent reviewers searched PubMed, EMBASE, and the Cochrane Library using the terms anterior cruciate ligament, ACL, drive, and driving. Studies reporting on functional recovery after ACLR were included when data regarding return to driving were reported.

Results

Five studies were included. Two studies included patients who underwent right-sided ACLR. Of these, 1 study evaluated bone-patellar tendon-bone autograft and reported that brake response time (BRT) returned to normal approximately 4 to 6 weeks postoperatively. The other study found that BRT returned to normal 3 weeks after allograft ACLR, but 6 weeks elapsed after autograft ACLR before values were not significantly different than controls. One study reported that patients who underwent left-sided hamstring tendon autograft ACLR demonstrated BRTs similar to controls within 2 weeks, while those with right-sided ACLR had significantly slower BRTs until 6 weeks postoperatively. Another study including patients who underwent either right- or left-sided ACLR and employed a manual transmission simulator found that 4 to 6 weeks should elapse after ACLR with hamstring tendon autograft. Survey data from 1 study demonstrated that the mean time for patients to resume driving was 13 and 10 days after right- and left-sided ACLR, respectively.

Conclusion

BRT returned to normal values approximately 4 to 6 weeks after right-sided ACLR and approximately 2 to 3 weeks after left-sided ACLR. According to 1 study in this review, ACLR laterality should be disregarded for patients who drive manual transmission automobiles, as a 4- to 6-week time period was required for driving ability to reach the level of healthy controls. Future studies should aim to elucidate the influence of graft choice and transmission type on return to driving after ACLR.

Editorial Commentary: Femoral Nerve Block: Don't Kill the Motor Branch

Femoral nerve block is commonly used for pain control after knee surgery and helps to reduce the need for opioids in the early postoperative period. The potential disadvantage is blockage of the motor branch of the femoral nerve, resulting in quadriceps weakness and reduced strength by up to 50%. Adductor canal nerve block is a possible alternative resulting in less muscle weakness. The rationale behind adductor canal nerve block is blockage of the saphenous nerve and part of the obturator nerve, providing reliable and adequate pain relief.