Efficacy of intravenous acetaminophen in multimodal management for pain relief following total knee arthroplasty: a meta-analysis

Intravenous Ketorolac Substantially Reduces Opioid Use and Length of Stay After Lumbar Fusion: A Randomized Controlled Trial

STUDY DESIGN

A randomized, double-blinded, placebo-controlled trial.

OBJECTIVE

To examine the effect of intravenous ketorolac (IV-K) on hospital opioid use compared with IV-placebo (IV-P) and IV acetaminophen (IV-A).

SUMMARY OF BACKGROUND DATA

Controlling postoperative pain while minimizing opioid use after lumbar spinal fusion is an important area of study.

PATIENTS AND METHODS

Patients aged 18 to 75 years undergoing 1 to 2 level lumbar fusions between April 2016 and December 2019 were included. Patients with chronic opioid use, smokers, and those on systemic glucocorticoids or contraindications to study medications were excluded. A block randomization scheme was used, and study personnel, hospital staff, and subjects were blinded to the assignment. Patients were randomized postoperatively. The IV-K group received 15 mg (age > 65) or 30 mg (age < 65) every six hours (q6h) for 48 hours, IV-A received 1000 mg q6h, and IV-P received normal saline q6h for 48 hours. Demographic and surgical details, opioid use in morphine milliequivalents, opioid-related adverse events, and length of stay (LOS) were recorded. The primary outcome was in-hospital opioid use up to 72 hours.

RESULTS

A total of 171 patients were included (58 IV-K, 55 IV-A, and 58 IV-P) in the intent-to-treat (ITT) analysis, with a mean age of 57.1 years. The IV-K group had lower opioid use at 72 hours (173 ± 157 mg) versus IV-A (255 ± 179 mg) and IV-P (299 ± 179 mg; P = 0.000). In terms of opiate use, IV-K was superior to IV-A ( P = 0.025) and IV-P ( P = 0.000) on ITT analysis, although on per-protocol analysis, the difference with IV-A did not reach significance ( P = 0.063). When compared with IV-P, IV-K patients reported significantly lower worst ( P = 0.004), best ( P = 0.001), average ( P = 0.001), and current pain ( P = 0.002) on postoperative day 1, and significantly shorter LOS ( P = 0.009) on ITT analysis. There were no differences in opioid-related adverse events, drain output, clinical outcomes, transfusion rates, or fusion rates.

CONCLUSIONS

By reducing opioid use, improving pain control on postoperative day 1, and decreasing LOS without increases in complications or pseudarthrosis, IV-K may be an important component of "enhanced recovery after surgery" protocols.

Oral versus intravenous acetaminophen for perioperative pain management in adult patients undergoing non-cardiac surgery: A quantile segmented regression analysis

STUDY OBJECTIVE

Determine whether preferential use of perioperative enteral acetaminophen is associated with changes in perioperative pain, narcotic administration, or time to meeting criteria for post anesthesia care unit (PACU) discharge, compared to preferential parenteral administration.

DESIGN

Retrospective Cohort with quantile segmented regression analysis. Groups determined by date of surgery, one year pre-initiative and one year post-initiative.

SETTING

Operating room and PACU of a tertiary academic medical center.

PATIENTS

Adult (age > 18 years), ASA status 1-5, non-pregnant patients undergoing non-cardiac surgery of less than six hours duration admitted to the PACU postoperatively.

INTERVENTIONS

A multidisciplinary initiative to preferentially utilize enteral over parenteral acetaminophen.

MEASUREMENTS

The primary outcome was narcotic consumption in the PACU. Secondary outcomes were intraoperative narcotic administration, pain score on PACU admission and discharge, and time to meeting criteria for PACU discharge.

RESULTS

24,701 patients were included in the analysis; 12,379 had surgery prior to the initiative and 12,322 after. Enteral acetaminophen administration increased preoperatively from 13.49% to 26.84%, and postoperatively from 43.16% to 51.45%, while intraoperative parenteral APAP use dropped from 43.23% to 6.81%. Quantile Segmented regression analysis after adjusting for period (pre versus postintervention), day, age, gender, inpatient status, and ASA class demonstrated a decrease in adjusted median perioperative acetaminophen dose (-175 mg P < 0.001), with no significant difference in level change of intraoperative or PACU narcotic administration. There was no significant difference in median time to meet criteria for PACU discharge, though there was a significant change in the slope, (-0.36, p = 0.007.) Median pain scores measured on a standard 0-10 numeric rating scale at PACU admission did not change, while median pain scores at PACU discharge decreased slightly (-0.24 p < 0.001). There was no change in the probability of PONV.

CONCLUSION

In adult patients undergoing non-cardiac surgery of <6 h duration, preferential use of enteral rather than parenteral acetaminophen is associated with non-inferior outcomes in narcotic requirements, pain scores, time to PACU discharge, and probability of PONV when compared with routine parenteral administration. Further studies are needed to validate these findings.

Ocular penetration of oral acetaminophen in horses

BACKGROUND

Acetaminophen (paracetamol) is increasingly used to treat painful conditions in horses but its ocular penetration has not been studied.

OBJECTIVES

To determine whether orally administered acetaminophen penetrates the aqueous humour of the normal equine eye and report an aqueous humour:serum acetaminophen concentration ratio in horses.

STUDY DESIGN

In vivo experiment.

METHODS

Six privately owned horses with normal ophthalmic examinations weighing 568 ± 65 kg (mean ± standard deviation) and aged 11 ± 4 years were given 20 mg/kg acetaminophen orally every 12 h for a total of six doses. Physical exam parameters were recorded prior to, during, and after the dosing period. One hour after the final dose, horses were sedated and simultaneous aqueous humour and serum samples were collected and analysed for acetaminophen concentrations and selected eicosanoids. An aqueous humour:serum acetaminophen concentration ratio was calculated. A second aqueous humour sample was taken and analysed for eicosanoid concentrations 3 months after acetaminophen dosing. Physical exam data were compared between time points using a mixed model analysis (significance p < 0.05).

RESULTS

Acetaminophen was detected in both serum and aqueous humour of all horses and mean ± standard deviation aqueous humour:serum acetaminophen concentration ratio was 44.9 ± 15.9%. No significant changes in physical exam parameters occurred during or after dosing. Eicosanoids were not detected in aqueous humour at any sampling point.

MAIN LIMITATIONS

Presence of acetaminophen in the aqueous humour may not relate to clinical effect. A therapeutic level of acetaminophen has not been determined in horses, and the absence of ocular inflammation does not reflect conditions in which acetaminophen may be used.

CONCLUSIONS

Acetaminophen readily penetrates the aqueous humour of the normal equine eye after consecutive oral dosing. Further study is required to determine whether acetaminophen is useful in the treatment of ocular pain and inflammation.

Is intravenous magnesium sulphate a suitable adjuvant in postoperative pain management? - A critical and systematic review of methodology in randomized controlled trials

A growing worldwide focus on opioid-free anaesthesia entails multimodal analgesic strategies involving non-opioids such as magnesium sulphate (MgSO4). Several systematic reviews have concluded there is beneficial analgesic effect of MgSO4 administration but do not take considerable heterogeneity among the studies into consideration. Medical literature published until June 2021 was searched in PubMed/Medline, Embase, Central and Web of Science: The final search yielded a total of 5,672 articles. We included only randomised controlled trials assessing the effect of intravenous MgSO4 on opioid consumption and acute postoperative pain when compared to either placebo or standardized analgesic treatment. The primary aim was to compare the homogeneity of essential variables and confounders. A post-hoc meta-analysis demonstrated a reduction in both postoperative morphine consumption (-6.12 mg) and pain score (-12.32 VAS points) in favour of the MgSO4-groups. Data for meta-analysis was missing from 19 studies (45%) on morphine consumption and 29 studies (69%) for pain score, the majority of which reports no effect for either morphine consumption or pain score. The calculated heterogeneity among the included studies was considerable for both outcomes; I 2=91% for morphine consumption and I 2=96% for pain score. Although we found a per se reduction in opioid consumption and pain score, methodological heterogeneity and clinical shortcomings of pre-, intra-, and post anaesthetic data precludes conclusions on clinical importance of intraoperative intravenous MgSO4. In addition, the reduction is likely less than what can be gained from using standardized analgesic treatment.

The Efficacy and Safety of Regional Nerve Blocks in Total Knee Arthroplasty: Systematic Review and Direct Meta-Analysis

BACKGROUND

Regional nerve blocks are widely used in primary total knee arthroplasty (TKA) to reduce postoperative pain and opioid consumption. The purpose of our study was to evaluate the efficacy and safety of regional nerve blocks after TKA in support of the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Management.

METHODS

We searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for studies published before March 24, 2020 on femoral nerve block, adductor canal block, and infiltration between Popliteal Artery and Capsule of Knee in primary TKA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of the regional nerve blocks compared to a control, local peri-articular anesthetic infiltration (PAI), or between regional nerve blocks.

RESULTS

Critical appraisal of 1,673 publications yielded 56 publications representing the best available evidence for analysis. Femoral nerve and adductor canal blocks are effective at reducing postoperative pain and opioid consumption, but femoral nerve blocks are associated with quadriceps weakness. Use of a continuous compared to single shot adductor canal block can improve postoperative analgesia. No difference was noted between an adductor canal block or PAI regarding postoperative pain and opioid consumption, but the combination of both may be more effective.

CONCLUSION

Single shot adductor canal block or PAI should be used to reduce postoperative pain and opioid consumption following TKA. Use of a continuous adductor canal block or a combination of single shot adductor canal block and PAI may improve postoperative analgesia in patients with concern of poor postoperative pain control.

The Ramifications of Opioid Utilization and Outcomes of Alternative Pain Control Strategies for Total Knee Arthroplasties

Morbidity and mortality related to opioid use has generated a public health crisis in the United States. Total knee arthroplasty (TKA) is an increasingly common procedure and is often accompanied by post-operative opioid utilization. Unfortunately, post-operative opioid usage after TKA has been shown to lead to higher rates of complications, longer hospital stays, increased costs, and more frequent need for revision surgery. Pre-operative opioid utilization has been shown to be one of the most important predictors of post-operative opioid usage. Additional risk factors for continued post-operative opioid utilization after TKA include pre-operative substance and tobacco use as well as higher post-operative prescription dosages, younger age, female gender, and Medicaid insurance. One method for mitigating excessive post-operative opioid utilization are Enhanced Recovery After Surgery (ERAS) protocols, which include a multidisciplinary approach that focuses on perioperative factors to optimize patient recovery and function after surgery. Additional strategies include multimodal pain regimens with epidural anesthetics, extended duration local anesthetics and adjuvants, and ultrasound guided peripheral nerve blocks. In recent years, opioid prescribing duration limitations have also been put into place by state and federal government, hospital systems, and ambulatory surgery centers making effective acute pain management imperative for all stakeholders. In this regard, as rates of TKA continue to increase across the United States, multidisciplinary efforts by all stakeholders are needed to ensure adequate pain control while preventing the negative sequalae of opioid medications.

Pain management after total knee arthroplasty: PROcedure SPEcific Postoperative Pain ManagemenT recommendations

BACKGROUND

The PROSPECT (PROcedure SPEcific Postoperative Pain ManagemenT) Working Group is a global collaboration of surgeons and anaesthesiologists formulating procedure-specific recommendations for pain management after common operations. Total knee arthroplasty (TKA) is associated with significant postoperative pain that is difficult to treat. Nevertheless, pain control is essential for rehabilitation and to enhance recovery.

OBJECTIVE

To evaluate the available literature and develop recommendations for optimal pain management after unilateral primary TKA.

DESIGN

A narrative review based on published systematic reviews, using modified PROSPECT methodology.

DATA SOURCES

A literature search was performed in EMBASE, MEDLINE, PubMed and Cochrane Databases, between January 2014 and December 2020, for systematic reviews and meta-analyses evaluating analgesic interventions for pain management in patients undergoing TKA.

ELIGIBILITY CRITERIA

Each randomised controlled trial (RCT) included in the selected systematic reviews was critically evaluated and included only if met the PROSPECT requirements. Included studies were evaluated for clinically relevant differences in pain scores, use of nonopioid analgesics, such as paracetamol and nonsteroidal anti-inflammatory drugs and current clinical relevance.

RESULTS

A total of 151 systematic reviews were analysed, 106 RCTs met PROSPECT criteria. Paracetamol and nonsteroidal anti-inflammatory or cyclo-oxygenase-2-specific inhibitors are recommended. This should be combined with a single shot adductor canal block and peri-articular local infiltration analgesia together with a single intra-operative dose of intravenous dexamethasone. Intrathecal morphine (100 μg) may be considered in hospitalised patients only in rare situations when both adductor canal block and local infiltration analgesia are not possible. Opioids should be reserved as rescue analgesics in the postoperative period. Analgesic interventions that could not be recommended were also identified.

CONCLUSION

The present review identified an optimal analgesic regimen for unilateral primary TKA. Future studies to evaluate enhanced recovery programs and specific challenging patient groups are needed.

A Randomized Controlled Pilot Study Using Ultrasound-Guided Percutaneous Cryoneurolysis of the Infrapatellar Branch of the Saphenous Nerve for Analgesia Following Total Knee Arthroplasty

INTRODUCTION

Total knee arthroplasty (TKA) is frequently associated with severe, prolonged postsurgical pain, and therefore local anesthetic-based peripheral nerve blocks are commonly used for postoperative analgesia. Cryoneurolysis involves the use of freezing temperatures to provide a reversible sensory (and motor) block with a duration measured in weeks and months, more commensurate with the typical period of post-TKA pain. We therefore conducted a randomized controlled pilot study to evaluate the use of this modality for the treatment of pain following TKA to (1) determine the feasibility of and optimize the study protocol for a subsequent definitive clinical trial; and (2) estimate analgesia and opioid reduction within the first 3 postoperative weeks.

METHODS

A convenience sample of 16 patients undergoing primary TKA with a single-injection and/or continuous adductor canal nerve block were randomized to receive either active cryoneurolysis or a sham procedure targeting the infrapatellar branch of the saphenous nerve, in a participant-masked fashion. This was a pilot study with a relatively small number of participants, and therefore resulting data were not analyzed statistically.

RESULTS

Compared with participants receiving sham, the active treatment group reported slightly lower average and worst pain scores as well as opioid consumption and sleep disturbances due to pain at a majority of postoperative time points between postoperative days (POD) 4-21.

CONCLUSIONS

Preoperative ultrasound-guided cryoneurolysis of the infrapatellar branch of the saphenous nerve is feasible and may provide analgesic benefits for multiple weeks following TKA. A definitive randomized controlled trial appears warranted.

The Routes of Administration for Acute Postoperative Pain Medication

Effective treatment of postoperative acute pain, together with early mobilization and nutrition, is one of the perioperative strategies advocated to improve surgical outcome and reduce the costs of hospitalization. Moreover, adequate pain control reduces perioperative morbidity related to surgical stress and can also prevent the incidence of chronic postoperative pain syndromes, whose treatment is still a challenge. The choice of the most appropriate analgesics depends not only on the drug class, but also on the most suitable route of administration, the best dosage for that route, and unique limitations and contraindications for every patient. In the present review, a comprehensive analysis was performed on the different routes of administration of acute postoperative pain medications and their indications and limitations, focusing on recent evidence and international recommendations.

Reducing opioid usage in total knee arthroplasty postoperative pain management: a literature review and future directions

Total knee arthroplasty (TKA) is a common orthopedic surgery performed with a projected 3.5 million procedures to be done by 2030. Current postoperative pain management for TKA is insufficient, as it results in extensive opioid consumption and functional decline postoperatively. This study identifies the best practices for postoperative TKA pain management through a literature review of the last three years. Studies utilizing interventional techniques (local infiltration analgesia, nerve blocks) and pharmacologic options were reviewed on PubMed, Embase, Ovid Medline and Scopus. Primary outcomes analyzed were the effect of different analgesic approaches on pain reduction, opioid use reduction and improvements in functional mobility or quadriceps strength postoperatively. Additionally, this paper explores the use of cooled radiofrequency ablation, a minimally invasive therapy, for preoperative and postoperative TKA pain management.

An Update on Multimodal Pain Management After Total Joint Arthroplasty

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Multimodal analgesia has become the standard of care for total joint arthroplasty as it provides superior analgesia with fewer side effects than opioid-only protocols.

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Systemic medications, including nonsteroidal anti-inflammatory drugs, acetaminophen, corticosteroids, and gabapentinoids, and local anesthetics via local infiltration analgesia and peripheral nerve blocks, are the foundation of multimodal analgesia in total joint arthroplasty.

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Ideally, multimodal analgesia should begin preoperatively and continue throughout the perioperative period and beyond discharge.

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There is insufficient evidence to support the routine use of intravenous acetaminophen or liposomal bupivacaine as part of multimodal analgesia protocols.

The Efficacy and Safety of Acetaminophen in Total Joint Arthroplasty: Systematic Review and Direct Meta-Analysis

BACKGROUND

Oral and intravenous (IV) acetaminophen has become widely used perioperatively as part of a multi-modal pain management protocol for primary total joint arthroplasty (TJA). The purpose of our study is to evaluate the efficacy and safety of acetaminophen in support of the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Management.

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials for studies published prior to September 2019 on acetaminophen in primary TJA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of acetaminophen.

RESULTS

In total, 1287 publications were critically appraised yielding 17 publications representing the best available evidence for analysis. Oral and IV acetaminophen demonstrates the ability to safely reduce postoperative pain and opioid consumption during the inpatient hospital stay. No evidence was available to assess the efficacy and safety of oral acetaminophen after discharge.

CONCLUSION

Moderate evidence supports the use of oral and IV acetaminophen as a non-opioid adjunct for pain management during the inpatient hospitalization. Strong evidence supports the safety of oral and IV acetaminophen when appropriately administered to patients undergoing primary TJA. Although there is lack of robust evidence for use of acetaminophen following discharge, it remains a low-cost and low-risk option as part of a multimodal pain regimen.

Randomized Clinical Trial of Intravenous (IV) Acetaminophen as an Adjunct to IV Hydromorphone for Acute Severe Pain in Emergency Department Patients

BACKGROUND

A fundamental challenge for emergency department (ED) clinicians is to relieve severe, acute pain while simultaneously avoiding adverse events associated with opioid analgesics. Because there is evidence that intravenous (IV) acetaminophen is an effective adjuvant analgesic in postoperative settings, we examined whether it also has a role in the ED.

METHODS

This was a two-arm, double-blind randomized clinical trial. All patients received 1 mg of IV hydromorphone. Patients were then randomized to receive 1 g of IV acetaminophen or placebo. The primary outcome was the between-group difference in change in pain from baseline (before treatment) to 60 minutes after administration of study drugs, measured on an 11-point numeric rating scale (NRS).

RESULTS

Of 828 patients screened, 162 were enrolled and 159 had the primary outcome. Patients allocated to acetaminophen + hydromorphone had a mean decline in pain from baseline to 60 minutes of 6.2 NRS units; those receiving placebo + hydromorphone had a mean decline of 5.4, a difference of 0.8 NRS units (95% confidence interval [CI] = -0.01 to 1.8). Two patients in each group received additional analgesics in the first 60 minutes of the study. At 120 minutes the NRS pain difference was 0.6 (95% CI = -0.4 to 1.6). A total of 26.9% of patients who received acetaminophen wanted more analgesia versus 37.7% of those given placebo (difference = -10.8%, 95% CI = -24.3% to 4.4%). The incidence of adverse effects was similar in both groups.

CONCLUSIONS

The addition of 1 g of IV acetaminophen to 1 mg of IV hydromorphone provided neither clinically meaningful nor statistically superior analgesia than hydromorphone alone.

Consensus Statement for the Prescription of Pain Medication at Discharge after Elective Adult Surgery

This Consensus Statement provides recommendations on the prescription of pain medication at discharge from hospital for opioid-naïve adult patients who undergo elective surgery. It encourages health care providers (surgeons, anesthesiologists, nurses/nurse practitioners, pain teams, pharmacists, allied health professionals, and trainees) to (1) use nonopioid therapies and reduce the prescription of opioids so that fewer opioid pills are available for diversion and (2) educate patients and their families/caregivers about pain management options after surgery to optimize quality of care for postoperative pain. These recommendations apply to opioid-naïve adult patients who undergo elective surgery. This consensus statement is intended for use by health care providers involved in the management and care of surgical patients. A modified Delphi process was used to reach consensus on the recommendations. First, the authors conducted a scoping review of the literature to determine current best practices and existing guidelines. From the available literature and expertise of the authors, a draft list of recommendations was created. Second, the authors asked key stakeholders to review and provide feedback on several drafts of the document and attend an in-person consensus meeting. The modified Delphi stakeholder group included surgeons, anesthesiologists, residents, fellows, nurses, pharmacists, and patients. After multiple iterations, the document was deemed complete. The recommendations are not graded because they are mostly based on consensus rather than evidence.