Intravenous Acetaminophen for Pain after Major Orthopedic Surgery: An Expanded Analysis

Prospective, Double-blind Evaluation of Perioperative Intravenous Acetaminophen and Ketorolac for Postoperative Pain and Opioid Consumption After Endoscopic Carpal Tunnel Release

Background: The current opioid epidemic highlights the need for pain management strategies to decrease or eliminate postoperative use of opioid medications. The purpose of this study was to determine if perioperative administration of intravenous (IV) acetaminophen and/or IV ketorolac decreases postoperative pain and opioid consumption after endoscopic carpal tunnel release. Methods: In all, 44 subjects were enrolled in this randomized, double-blind, placebo-controlled study from October 2015 to April 2017 and divided into 4 treatment arms: placebo, IV acetaminophen, IV ketorolac, or both IV acetaminophen and IV ketorolac. Patients recorded pain at 8-hour intervals on an 11-point scale and daily opioid use for 7 days after surgery. Analysis of variance and Kruskal-Wallis tests were used to compare mean pain scores and opioid consumption. Results: Mean pain scores over the 7-day study period were lower in the placebo and IV acetaminophen groups. Patients in the placebo and acetaminophen groups reported less pain than those in the ketorolac and combination groups on postoperative days 6 and 7. Patients administered IV acetaminophen had lower daily mean opioid usage. In all, 50% of the patients did not take any opioids after surgery. Conclusions: There are small, statistically significant differences in postoperative pain and opioid consumption supporting the use of IV acetaminophen for pain control after endoscopic carpal tunnel release, though these results are likely not clinically relevant. We recommend continued investigation into multimodal pain management in upper extremity surgery as well as limiting the number and quantity of opioid prescriptions provided to patients postoperatively.

Assessing efficacy of intravenous acetaminophen for perioperative pain control for oocyte retrieval: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To compare the effect of preoperative intravenous (IV) acetaminophen versus oral (PO) acetaminophen or placebo on postoperative pain scores and the time to discharge in women undergoing oocyte retrieval.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Single academic fertility center.

PATIENT(S)

Women aged 18-43 years undergoing oocyte retrieval.

INTERVENTION(S)

Randomization to preoperative 1,000 mg IV acetaminophen and PO placebo (group A), IV placebo and 1,000 mg PO acetaminophen (group B), or IV and PO placebo (group C) MAIN OUTCOME MEASURE(S): Difference in patient-reported postoperative visual analog scale pain scores from baseline and the time to discharge.

RESULT(S)

Of the 159 women who completed the study, there were no differences in the mean postoperative pain score differences or the time to discharge. Although not statistically significant, the mean postoperative opioid dose requirement in group A was lower than that in groups B and C (0.24 vs. 0.59 vs. 0.58 mg IV morphine equivalents, respectively) due to fewer women in group A requiring rescue pain medication (8% vs. 19% vs. 15%, respectively). Group A also reported less constipation when compared with groups B and C (19% vs. 33% vs. 40%, respectively). The rates of postoperative nausea were similar, and there were no differences in embryology or early pregnancy outcomes between the study groups.

CONCLUSION(S)

Preoperative IV acetaminophen for women undergoing oocyte retrieval did not reduce postoperative pain scores or shorten the time to discharge when compared with PO acetaminophen or placebo and, thus, cannot currently be recommended routinely in this patient population.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03073980.

PROSPECT guideline for total hip arthroplasty: a systematic review and procedure-specific postoperative pain management recommendations

The aim of this systematic review was to develop recommendations for the management of postoperative pain after primary elective total hip arthroplasty, updating the previous procedure-specific postoperative pain management (PROSPECT) guidelines published in 2005 and updated in July 2010. Randomised controlled trials and meta-analyses published between July 2010 and December 2019 assessing postoperative pain using analgesic, anaesthetic, surgical or other interventions were identified from MEDLINE, Embase and Cochrane databases. Five hundred and twenty studies were initially identified, of which 108 randomised trials and 21 meta-analyses met the inclusion criteria. Peri-operative interventions that improved postoperative pain include: paracetamol; cyclo-oxygenase-2-selective inhibitors; non-steroidal anti-inflammatory drugs; and intravenous dexamethasone. In addition, peripheral nerve blocks (femoral nerve block; lumbar plexus block; fascia iliaca block), single-shot local infiltration analgesia, intrathecal morphine and epidural analgesia also improved pain. Limited or inconsistent evidence was found for all other approaches evaluated. Surgical and anaesthetic techniques appear to have a minor impact on postoperative pain, and thus their choice should be based on criteria other than pain. In summary, the analgesic regimen for total hip arthroplasty should include pre-operative or intra-operative paracetamol and cyclo-oxygenase-2-selective inhibitors or non-steroidal anti-inflammatory drugs, continued postoperatively with opioids used as rescue analgesics. In addition, intra-operative intravenous dexamethasone 8-10 mg is recommended. Regional analgesic techniques such as fascia iliaca block or local infiltration analgesia are recommended, especially if there are contra-indications to basic analgesics and/or in patients with high expected postoperative pain. Epidural analgesia, femoral nerve block, lumbar plexus block and gabapentinoid administration are not recommended as the adverse effects outweigh the benefits. Although intrathecal morphine 0.1 mg can be used, the PROSPECT group emphasises the risks and side-effects associated with its use and provides evidence that adequate analgesia may be achieved with basic analgesics and regional techniques without intrathecal morphine.

Review of Intravenous Acetaminophen for Analgesia in the Postoperative Setting

BACKGROUND

Acetaminophen is a non-opioid analgesic commonly utilized for pain control after several types of surgical procedures.

METHODS

This scoping primary literature review provides recommendations for intravenous (IV) acetaminophen use based on type of surgery.

RESULTS

Intravenous acetaminophen has been widely studied for postoperative pain control and has been compared to other agents such as NSAIDs, opioids, oral/rectal acetaminophen, and placebo. Some of the procedures studied include abdominal, gynecologic, orthopedic, neurosurgical, cardiac, renal, and genitourinary surgeries. Results of these studies have been conflicting and largely have not shown consistent clinical benefit.

CONCLUSION

Overall, findings from this review did not support the notion that IV acetaminophen has significant efficacy for postoperative analgesia. Given the limited clinical benefit of IV acetaminophen, especially when compared to the oral or rectal formulations, use is generally not justifiable.

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.

Similar Outcomes After Hospital-Based Same-Day Discharge vs Inpatient Total Hip Arthroplasty

Background

There has been increasing interest in performing primary hip and knee replacement with same-day discharge (SDD). The purpose of this study is to compare patient-reported outcome (PRO) scores, pain scores, and readmissions in patients who underwent SDD total hip arthroplasty (THA) with those in patients who underwent traditional inpatient THA.

Methods

A retrospective study was conducted on 963 patients who underwent primary THA at our institution between September 2016 and December 2018. Two cohorts were established based on whether the patient underwent SDD or traditional inpatient THA. An electronic physical engagement application was used to collect PRO scores (Hip Disability and Osteoarthritis Outcome Score for Joint Replacement, Veterans Rand 12-Item Health Survey Physical Component Score, and Mental Component Score) and pain scores. To control for demographic variables, a multiple regression analysis of PRO scores was conducted.

Results

Four hundred fifteen (43.1%) patients in this study underwent the SDD protocol. There were significant differences between both cohorts with respect to sex, age, body mass index, American Society of Anesthesiologists score, and smoking status. The bivariate analysis revealed that the SDD cohort had a significantly greater change in the Veterans Rand 12-Item Health Survey Physical Component Score and had fewer readmissions. Both cohorts had equivalent decreases in pain scores. After controlling for demographic variables in a multivariable analysis, the SDD cohort was found to have higher PRO scores at all time points, but there were no significant differences in the change in PRO scores over time between both groups.

Conclusion

Patients in an SDD THA care pathway experienced similar improvements in PRO scores and clinically equal reduction in pain scores.

Effect of scheduled intravenous acetaminophen on postoperative nausea and vomiting in patients undergoing laparoscopic gynecologic surgery

PURPOSE

The aim of this study was to assess the effect of scheduled intravenous acetaminophen (SIVA) on the incidence of postoperative nausea and vomiting (PONV) in patients undergoing laparoscopic gynecologic surgery (LGS).

METHODS

This retrospective observational study identified consecutive patients who underwent LGS at our institution from January to November of 2017 and were managed with either our hospital's old protocol (Group H) or a new protocol using SIVA (Group S). Primary outcomes included the incidences of PONV and the amount of additional antiemetic required in the postoperative period. The secondary outcomes included the pain score on postoperative day 1, the requirement for additional analgesic medications, and the length of hospitalization (LOH).

RESULTS

Patients in Group S had significantly lower incidences of PONV from postoperative days 0 to 1 and required significantly less antiemetics or tramadol than those in Group H (P = 0.0085). Patients at a low risk for PONV in Group S had significantly lower incidences of PONV than those in Group H (P = 0.0129). Further, the amount of additional tramadol required was lower in Group S than in Group H (P = 0.0021).

CONCLUSION

Introduction of SIVA into the postoperative pain management protocol of LGS may reduce the incidence of PONV and the amount of adjunctive antiemetic medication required from postoperative days 0 to 1. In patients undergoing LGS, PONV prophylaxis using antiemetics should be prescribed depending on PONV risk profile; however, SIVA prophylaxis can be used in all patients regardless of PONV risk profile.

Evolution of an Opioid Sparse Pain Management Program for Total Knee Arthroplasty With the Addition of Intravenous Acetaminophen

BACKGROUND

Perioperative pain management for patients undergoing total knee arthroplasty (TKA) improves patient outcomes and facilitates recovery. In this study, we compared the effects of preoperative oral acetaminophen vs intravenous (IV) acetaminophen administered once intraoperatively and once postoperatively.

METHODS

Two standardized, multimodal analgesia protocols were compared in patients undergoing primary, unilateral TKA. The oral acetaminophen cohort (OA) received doses of oral acetaminophen preoperatively and an as-needed basis postoperatively (n = 698). The IV acetaminophen cohort (IA) received 2 doses of IV acetaminophen, one intraoperative and one 6 hours postoperatively, with no oral acetaminophen given (n = 318). No other variables were significantly changed during the study period.

RESULTS

The IV acetaminophen group demonstrated less narcotic usage on postoperative day 0 (OA: 13.3 mme [morphine mg equivalents], IA: 6.2 mme, P < .001) and overall usage (OA: 66.1 mme, IA: 48.5 mme, P < .001). Pain scores were statistically and clinically significantly decreased in the immediate postoperative (the first 8 hours) for the IA group (OA: patient-reported pain scores of 4.0; IA: patient-reported pain scores of 2.0, P < .001). Both groups progressed and completed their physical therapy similarly for each postoperative day. Length of stay and percent discharge home were slightly improved in the IA group as well, however did not reach statistical difference.

CONCLUSION

An iterative approach to multimodal pain management after TKA led to improvements in narcotic usage, pain scores, and several quality measures. IV acetaminophen is an integral and effective part of our opioid-sparing multimodal pain regimen in TKA.

A Novel Opioid-Sparing Pain Management Protocol Following Total Hip Arthroplasty: Effects on Opioid Consumption, Pain Severity, and Patient-Reported Outcomes

BACKGROUND

Opioid prescriptions and subsequent opioid-related deaths have increased substantially in the past several decades. Orthopedic surgery ranks among the highest of all specialties with respect to the amount of opioids prescribed. We present here the outcomes of our opioid-sparing pain management pilot protocol for total hip arthroplasty (THA).

METHODS

A retrospective study was conducted to assess outcomes before and after the implementation of an opioid-sparing pain management protocol for THA. Patients were divided into 2 cohorts for comparison: (1) traditional pain management protocol and (2) opioid-sparing pain management protocol. The Hip Disability and Osteoarthritis Outcome Score for Joint Replacement, pain severity using a Visual Analog Scale, and inpatient morphine milligram equivalents (MMEs) per day were compared between the 2 cohorts.

RESULTS

No statistically significant difference was observed in Hip Disability and Osteoarthritis Outcome Score for Joint Replacement between the 2 cohorts at any time point (P > .05). Although there was a significant decrease in pain scores over time (P < .01), there was no statistically significant difference in the rates of change between the 2 pain management protocols at any time point (P = .463). Inpatient opioid consumption was significantly lower for the opioid-sparing cohort in comparison to the traditional cohort (14.6 ± 16.7 vs 25.7 ± 18.8 MME/d, P < .001). Similarly, the opioid-sparing cohort received significantly less opioids than the traditional cohort during the post discharge period (13.9 ± 24.2 vs 80.1 ± 55.9 MME, P < .001).

CONCLUSION

The results of this study suggest that an opioid-sparing protocol reduces opioid consumption and provides equivalent pain management and patient-reported outcomes during the 90-day THA episode of care relative to a traditional opioid-based regimen. These findings may help decrease the risk of adverse events associated with postoperative opioid use and provide a means of decreasing the opioid footprint in clinical practice.

Effectiveness of intravenous acetaminophen for postoperative pain management in shoulder arthroplasties: A population-based study

Background

Intravenous acetaminophen (IV APAP) is an option in multimodal postoperative analgesia. Prior trials focus on hip and knee arthroplasties, whereas large-scale data on utilization and effectiveness in shoulder arthroplasties are lacking.

Methods

Data on 67,494 (452 hospitals) partial/total shoulder arthroplasties were extracted from the Premier claims database (2011-2016). Patients were categorized by receipt and dosage of IV APAP. Multilevel models measured associations between IV APAP and opioid utilization (in oral morphine equivalents), length/cost of stay and opioid-related complications. Effect estimates (adjusted % change) with 95% confidence intervals (CIs) are reported.

Results

IV APAP was used in 17.7% (n = 11,949) of patients with an increasing utilization trend. Most patients received only one dose on the day of surgery (69.5%; n = 8308). When adjusting for relevant covariates, IV APAP was not associated with meaningful effects on outcomes. Specifically, its use (versus no use) was not associated with decreased (but rather somewhat increased) opioid utilization: + 5.4% (CI 3.6-7.1%; P < 0.05).

Conclusion

In this first large-scale study that assesses IV APAP in shoulder arthroplasties, IV APAP use was not associated with decreased opioid utilization or the length/cost of stay. These results do not support routine use of IV APAP in this cohort, especially given its high cost.

The translational potential for this article

Multimodal pain control to assist in reducing the opioid pain medications are seen as a route to improved postoperative patient outcomes, better pain control and expedited hospital discharge. Acetaminophen plays a significant role in these protocols in many institutions, but it is not established if this expensive IV formulation is superior to the oral formulation. This study evaluates the use and effectiveness of IV acetaminophen following shoulder arthroplasty at a large number of institutions.

Evaluating the Effect of Intravenous Acetaminophen in Multimodal Analgesia After Total Hip Arthroplasty: A Randomized Controlled Trial

BACKGROUND

Postoperative pain is a significant concern of patients before surgery. Multimodal pain management is an effective method of pain control after major orthopedic surgery. Acetaminophen is the most commonly used analgesic for the management of pain. It was hypothesized that 1000 mg of intravenous acetaminophen (IA) dosed every 6 hours would significantly reduce the postoperative pain score at rest and the opioid consumption volume in patients who would undergo total hip arthroplasty (THA) when compared to a control group.

METHODS

A single-center, prospective, open-label randomized control study was conducted. A total of 97 patients undergoing unilateral primary THA were divided into 2 groups: the study group (IA) (n = 45) and the control group (n = 52). The study group received administered IA after surgery, while the control group received only a standard pain control. Both groups received a preoperative femoral nerve block and postoperative intravenous fentanyl citrate. The primary outcome was the evaluation of the pain score at rest 24 hours after surgery. The pain score was measured using the Numerical Rating Scale. The primary outcome of this study was analyzed using generalized estimating equation.

RESULTS

The IA group had a significant improvement in Numerical Rating Scale score at rest 24 hours after THA compared to the control group (-0.91, 95% confidence interval -1.56 to -0.26, P = .006), suggesting a positive effect of IA usage for pain relief. The total fentanyl citrate consumption after surgery for 24 hours was significantly lower in the IA group than those of the control group (52.07 ± 7.64 vs 57.83 ± 12.44 mg, P < .001).

CONCLUSION

Postoperative administration of IA significantly reduced the postoperative pain score and opioid consumption volume after primary THA. IA was useful as one role of multimodal pain management after THA.

LEVEL OF EVIDENCE

Level 2.

Approaches to Pediatric Musculoskeletal Pain: Opioids and So Much More

Treatment of musculoskeletal pain in children poses unique challenges, particularly in the context of the ongoing opioid epidemic. In addition to the developmental level of the child, the type of pain he or she is experiencing should influence the team's approach when collaborating with the patient and the family to develop and refine pain management strategies. Understanding the categories of pain that may result from specific types of musculoskeletal injuries or orthopaedic surgeries influences the selection of medication or other most appropriate treatment. Although opioids are an important part of managing acute pain in the pediatric population, many other pharmacological and nonpharmacological therapies can be used in combination with or in place of opioids to optimize pain management. This article will review strategies for collaborating with families and the multidisciplinary team, provide an overview of pediatric pain assessment including assessment of acute musculoskeletal pain in children, and discuss pharmacological and nonpharmacological options for managing pain after acute injury or surgery.

The role of intravenous acetaminophen in post-operative pain control in head and neck cancer patients

OBJECTIVE

This study investigated the role of intravenous acetaminophen for alleviation of postoperative pain after surgical resection of head and neck cancers.

METHODS

A single-center study was conducted, which investigated a prospective group of 48 participants who underwent surgery between April 2016 and May 2017 and postoperatively received scheduled IV acetaminophen (1 g every 6 hours for 4 doses) plus the standard opioid PCA and breakthrough narcotics. These were compared to a similar retrospective cohort of 51 patients who had surgery between January 2014 to March 2015 and only received an opioid patient controlled analgesia (PCA) pump and breakthrough narcotics. Outcome measures included averaged pain scores, total amount of narcotics received (in morphine equivalents), and number of PCA attempts measured in 8-hour intervals over the first 24 hours, as well as duration of PCA and length of stay. Statistical measures included descriptive analysis and gamma regression analysis.

RESULTS

The acetaminophen group achieved equally low pain scores (0.8 ± 1.2 vs. 1.0 ± 1.3, P = .408) with significantly less total narcotics in the first 8 hours after surgery (13.5 ± 13.3 vs. 22.5 ± 21.5 MEs, P = .014). This group had a significantly decreased length of stay (7.8 ± 4.6 vs. 10.6 ± 7.6 days, P = .03).

CONCLUSION

This study demonstrates that intravenous acetaminophen may play a role in reducing the total narcotic requirement in the first 8 hours after surgery and contribute to a decreased length of stay and potentially decrease cost to the patient and hospital overall. Future research should be aimed at comparing these groups in a randomized control study/setting.

LEVEL OF EVIDENCE

3.

Updates on Multimodal Analgesia for Orthopedic Surgery

Pain control after orthopedic surgery is challenging. A multimodal approach provides superior analgesia with fewer side effects compared with opioids alone. This approach is particularly useful in light of the current opioid epidemic in the United States. Several new nonopioid agents have emerged into the market in recent years. New agents included in this review are intravenous acetaminophen, intranasal ketorolac, and newer nonsteroidal anti-inflammatory drugs, and the established medications ketamine and gabapentinoids. This article evaluates the evidence supporting these drugs in a multimodal context, including a brief discussion of cost.

A Preliminary Examination of the Comparative Efficacy of Intravenous vs Oral Acetaminophen in the Treatment of Perioperative Pain

Objective

The management of postoperative pain is a major health care issue. While the cost of intravenous acetaminophen (IVA) is significantly greater than its oral acetaminophen (OA) counterpart, less is known regarding comparative effectiveness of these routes. The purpose of this study was to determine whether perioperative IVA is equivalent in reducing postoperative pain compared with perioperative OA for laparoscopic cholecystectomy (LapChole).

Design

Double-blinded, prospective, randomized placebo-controlled trial.

Setting

Womack Army Medical Center, Fort Bragg, North Carolina.

Subjects

Adults (age > 18 years) active duty military, veterans, and beneficiaries receiving a laparoscopic cholecystectomy.

Methods

This study was conducted at Womack Army Medical Center (WAMC), Fort Bragg, North Carolina, between January 2013 and June 2015. Sixty-seven subjects with symptomatic cholelithiasis were randomly assigned to receive two doses (1,000 mg each) of either IVA or OA. A numerical rating scale (NRS) score of pain was obtained preoperatively and every six hours for 24 hours postoperation. The primary objective was to assess whether treatment groups had significantly different 24-hour postoperative sum of pain intensity differences (SPID24) using an analysis of covariance test.

Results

Sixty subjects completed the study and were included in the analysis. Treatment groups did not differ in SPID24, even when controlling for age, gender, and preoperative pain levels (F(1,55) = 0.39, P = 0.54, partial η2 = 0.007), nor did 24-hour opioid consumption when controlling for age, gender, and operation time (F(1, 46) = 0.47, P = 0.50, partial η2 = 0.01). Furthermore, treatment groups were equally as likely to report average postoperative NRS scores of 4 or higher (β = 0.24, Exp(B) = 1.28, P = 0.68).

Conclusions

The results show no evidence of differences between IVA or OA in pain or opioid consumption among a sample of patients undergoing LapChole. Due to low sample size, these descriptive findings warrant larger studies, which may have a significant economic impact.

Effectiveness of Novel Adjuncts in Pain Management Following Total Knee Arthroplasty: A Randomized Clinical Trial

BACKGROUND

Total knee arthroplasty (TKA) can be associated with significant pain which can negatively impact outcomes. Multiple strategies have been employed to reduce pain. The aim of this study is to compare the effectiveness of 3 different pain management modalities after TKA that included (1) our standardized knee injection cocktail and oral acetaminophen, (2) liposomal bupivacaine periarticular injection and oral acetaminophen, and (3) our standardized knee injection cocktail and intravenous (IV) acetaminophen.

METHODS

A prospective randomized clinical trial was conducted with 3 perioperative pain management regimes: oral acetaminophen and our standardized knee injection cocktail (standard group), oral acetaminophen and liposomal bupivacaine periarticular injection (LB group), and IV acetaminophen and our standardized knee injection cocktail (IVA group). Primary outcome measures included visual analog scale, total morphine equivalents, and the opioid-related symptoms distress scale at 24 and 48 hours postoperatively.

RESULTS

There were no significant differences on visual analog scale/opioid-related symptoms distress scale scores 24 hours after surgery. The LB group required significantly more narcotics (total morphine equivalents) than the standard (P = .025) and IVA groups (P = .032). No significant differences were observed on any of the outcomes measured at 48 hours after surgery.

CONCLUSION

Our data suggest that there is no added benefit in the routine use of IV acetaminophen or liposomal bupivacaine after TKA.

Multimodal analgesia decreases opioid consumption after shoulder arthroplasty: a prospective cohort study

BACKGROUND

Studies on perioperative pain control in shoulder arthroplasty focus on regional anesthesia, with little research on other approaches. Perioperative multimodal analgesia regimens decrease opioid intake and opioid-related side effects in lower-extremity arthroplasty. In this study we compare pain scores, opioid consumption, length of stay, and readmission rates in postoperative shoulder arthroplasty patients treated with a standard or multimodal analgesia regimen.

METHODS

A prospective cohort analysis was performed at a single institution. Patients undergoing elective shoulder arthroplasty were treated with either a standard opioid-based regimen or a multimodal analgesia regimen perioperatively. Outcome measures included inpatient pain scores, opioid use, length of stay, and 30- and 90-day emergency department visits and readmission rates.

RESULTS

Seventy-five patients were included in each cohort. Patients treated with the multimodal analgesia regimen had lower postoperative day 0 pain scores (mean, 1.5 vs 2.2; P = .027). Opioid use in the multimodal cohort was lower on all days: 47% lower on postoperative day 0, 37% on day 1, and 44% on day 2 (all P < .01). The length of inpatient stay was significantly shorter for multimodal patients than for patients treated with the standard regimen (1.44 days vs 1.91 days, P < .01). There was no difference in the rate of 30- or 90-day emergency department visits or readmission.

CONCLUSION

Patients undergoing shoulder arthroplasty have decreased postoperative pain and opioid consumption and shorter hospital stays when given a multimodal analgesia regimen. There is no increase in short-term complications or unplanned readmissions, indicating that this is a safe and effective means to control postoperative pain.

Intravenous vs Oral Acetaminophen as an Adjunct to Multimodal Analgesia After Total Knee Arthroplasty: A Prospective, Randomized, Double-Blind Clinical Trial

BACKGROUND

The efficacy of intravenous (IV) acetaminophen compared with its oral formulation for postoperative analgesia is unknown. We hypothesized that the addition of acetaminophen to a multimodal analgesia regimen would provide improved pain management in patients after total knee arthroplasty (TKA) and that the effect of acetaminophen would be variable based on the route of delivery.

METHODS

The study was a single-center, randomized, double-blinded, placebo-controlled clinical trial on the efficacy of IV vs oral acetaminophen in patients undergoing unilateral TKA. One hundred seventy-four subjects were randomized to one of the 3 groups: IV acetaminophen group (IV group, n = 57) received 1 g IV acetaminophen and oral placebo before postanesthesia care unit (PACU) admission; oral acetaminophen group (PO group, n = 58) received 1 g oral acetaminophen and volume-matched IV normal saline; placebo group (Placebo group, n = 59) received oral placebo and volume-matched IV normal saline. Pain scores were obtained every 15 minutes during PACU stay. Average pain scores, maximum pain score, and pain scores before physical therapy were compared among the 3 groups. Secondary outcomes included total opiate consumption, time to PACU discharge, time to rescue analgesia, and time to breakthrough pain.

RESULTS

The average PACU pain score was similar in the IV group (0.56 ± 0.99 [mean ± standard deviation]) compared with the PO group (0.67 ± 1.20; P = .84) and Placebo group (0.58 ± 0.99; P = .71). Total opiate consumption at 6 hours (0.47 mg hydromorphone equivalents ± 0.56 vs 0.54 ± 0.53 vs 0.54 ± 0.61; P = .69) and at 24 hours (1.25 ± 1.30 vs 1.49 ± 1.34 vs 1.36 ± 1.31; P = .46) were also similar between the IV, PO, and Placebo groups. No significant differences were found between all groups for any other outcome.

CONCLUSION

Neither IV nor oral acetaminophen provides additional analgesia in the immediate postoperative period when administered as an adjunct to multimodal analgesia in patients undergoing TKA in the setting of a spinal anesthetic.

Oral Multimodal Analgesia for Total Joint Arthroplasty

BACKGROUND

Oral multimodal analgesia for hip and knee arthroplasty is increasingly used as part of enhanced recovery protocols designed to minimize early postoperative pain and to facilitate early discharge, while minimizing undesirable side effects related to single-agent opioid administration.

METHODS

This article is a review of previously published data evaluating the use of various oral medications in the management of postoperative pain after lower extremity arthroplasty and was presented as part of a symposium at the November 2016 AAHKS Annual Meeting.

RESULTS

Multimodal analgesia has been shown to reduce opioid consumption and side effects, with a positive effect on both early and longer term outcomes for hip and knee arthroplasty patients. Medications directed at multiple points on the pain cascade minimize pain by different mechanisms. Suggested dosing regimens are proposed.

CONCLUSION

Oral multimodal analgesia incorporating a combination of opioid and nonopioid analgesics, selective and nonselective anti-inflammatory drugs, acetaminophen, and gabapentinoids are recommended as a part of a pre-emptive approach to pain management in patients undergoing hip or knee arthroplasty. Reduction of opioid consumption and minimization of side effects are primary outcomes, and prevention of chronic pain can positively affect long-term results.

Randomized Prospective Trial Comparing the Use of Intravenous versus Oral Acetaminophen in Total Joint Arthroplasty

BACKGROUND

Multimodal pain management has had a significant effect on improving total joint arthroplasty recovery and patient satisfaction. There is literature supporting that intravenous (IV) acetaminophen reduces postoperative pain and narcotic use in the total joint population. However, there are no studies comparing the effectiveness of IV vs oral (PO) acetaminophen as part of a standard multimodal perioperative pain regimen.

METHODS

One hundred twenty patients undergoing hip and knee arthroplasty surgeries performed by one joint arthroplasty surgeon were prospectively randomized into 2 groups. Group 1 (63 patients) received IV and group 2 (57 patients) received PO acetaminophen in addition to a standard multimodal perioperative pain regimen. Each group received 1 gram of acetaminophen preoperatively and then every 6 hours for 24 hours. Total narcotic use and visual analog scale (VAS) scores were collected every 4 hours postoperatively.

RESULTS

The 24-hour average hydromorphone equivalents given were not different between groups (3.71 vs 3.48) at 24 hours (P = .76), or at any of the individual 4-hour intervals. The 24-hour average visual analog scale scores in group 1 (IV) was 3.00 and in group 2 (PO) was 3.40 (P = .06). None of the 4-hour intervals were significantly different except the first interval (0-4 hour postoperatively), which favored the IV group (P = .03).

CONCLUSION

The use of IV acetaminophen may have a role when given intraoperatively to reduce the immediate pain after surgery. Following that, it does not provide a significant benefit in reducing pain or narcotic use when compared with the much less expensive PO form.

The Role of Multimodal Analgesia in Spine Surgery

Optimal postoperative pain control allows for faster recovery, reduced complications, and improved patient satisfaction. Historically, pain management after spine surgery relied heavily on opioid medications. Multimodal regimens were developed to reduce opioid consumption and associated adverse effects. Multimodal approaches used in orthopaedic surgery of the lower extremity, especially joint arthroplasty, have been well described and studies have shown reduced opioid consumption, improved pain and function, and decreased length of stay. A growing body of evidence supports multimodal analgesia in spine surgery. Methods include the use of preemptive analgesia, NSAIDs, the neuromodulatory agents gabapentin and pregabalin, acetaminophen, and extended-action local anesthesia. The development of a standard approach to multimodal analgesia in spine surgery requires extensive assessment of the literature. Because a substantial number of spine surgeries are performed annually, a standardized approach to multimodal analgesia may provide considerable benefits, particularly in the context of the increased emphasis on accountability within the healthcare system.

Pain relief that matters to patients: systematic review of empirical studies assessing the minimum clinically important difference in acute pain

BACKGROUND

The minimum clinically important difference (MCID) is used to interpret the clinical relevance of results reported by trials and meta-analyses as well as to plan sample sizes in new studies. However, there is a lack of consensus about the size of MCID in acute pain, which is a core symptom affecting patients across many clinical conditions.

METHODS

We identified and systematically reviewed empirical studies of MCID in acute pain. We searched PubMed, EMBASE and Cochrane Library, and included prospective studies determining MCID using a patient-reported anchor and a one-dimensional pain scale (e.g. 100 mm visual analogue scale). We summarised results and explored reasons for heterogeneity applying meta-regression, subgroup analyses and individual patient data meta-analyses.

RESULTS

We included 37 studies (8479 patients). Thirty-five studies used a mean change approach, i.e. MCID was assessed as the mean difference in pain score among patients who reported a minimum degree of improvement, while seven studies used a threshold approach, i.e. MCID was assessed as the threshold in pain reduction associated with the best accuracy (sensitivity and specificity) for identifying improved patients. Meta-analyses found considerable heterogeneity between studies (absolute MCID: I² = 93%, relative MCID: I² = 75%) and results were therefore presented qualitatively, while analyses focused on exploring reasons for heterogeneity. The reported absolute MCID values ranged widely from 8 to 40 mm (standardised to a 100 mm scale) and the relative MCID values from 13% to 85%. From analyses of individual patient data (seven studies, 918 patients), we found baseline pain strongly associated with absolute, but not relative, MCID as patients with higher baseline pain needed larger pain reduction to perceive relief. Subgroup analyses showed that the definition of improved patients (one or several categories improvement or meaningful change) and the design of studies (single or multiple measurements) also influenced MCID values.

CONCLUSIONS

The MCID in acute pain varied greatly between studies and was influenced by baseline pain, definitions of improved patients and study design. MCID is context-specific and potentially misguiding if determined, applied or interpreted inappropriately. Explicit and conscientious reflections on the choice of a reference value are required when using MCID to classify research results as clinically important or trivial.

Hospitalization Costs for Patients Undergoing Orthopedic Surgery Treated With Intravenous Acetaminophen (IV-APAP) Plus Other IV Analgesics or IV Opioid Monotherapy for Postoperative Pain

INTRODUCTION

To assess the impact on hospitalization costs of multimodal analgesia (MMA), including intravenous acetaminophen (IV-APAP), versus IV opioid monotherapy for postoperative pain management in patients undergoing orthopedic surgery.

METHODS

Utilizing the Truven Health MarketScan® Hospital Drug Database (HDD), patients undergoing total knee arthroplasty (TKA), total hip arthroplasty (THA), or surgical repair of hip fracture between 1/1/2011 and 8/31/2014 were separated into postoperative pain management groups: MMA with IV-APAP plus other IV analgesics (IV-APAP group) or an IV opioid monotherapy group. All patients could have received oral analgesics. Baseline characteristics and total hospitalization costs were compared. Additionally, an inverse probability treatment weighting [IPTW] with propensity scores analysis further assessed hospitalization cost differences.

RESULTS

The IV-APAP group (n = 33,954) and IV opioid monotherapy group (n = 110,300) differed significantly (P < 0.0001) across baseline characteristics, though the differences may not have been clinically meaningful. Total hospitalization costs (mean ± standard deviation) were significantly lower for the IV-APAP group than the IV opioid monotherapy group (US$12,540 ± $9564 vs. $13,242 ± $35,825; P < 0.0001). Medical costs accounted for $701 of the $702 between-group difference. Pharmacy costs were similar between groups. Results of the IPTW-adjusted analysis further supported the statistically significant cost difference.

CONCLUSIONS

Patients undergoing orthopedic surgery who received MMA for postoperative pain management, including IV-APAP, had significantly lower total costs than patients who received IV opioid monotherapy. This difference was driven by medical costs; importantly, there was no difference in pharmacy costs. Generalizability of the results may be limited to patients admitted to hospitals similar to those included in HDD. Dosing could not be determined, so it was not possible to quantify utilization of IV-APAP or ascertain differences in opioid consumption between the 2 groups. This study did not account for healthcare utilization post-discharge.

Single dose intravenous paracetamol or intravenous propacetamol for postoperative pain

BACKGROUND

This is an updated version of the original Cochrane review published in Issue 10, 2011. Paracetamol (acetaminophen) is the most commonly prescribed analgesic for the treatment of acute pain. It may be administered orally, rectally, or intravenously. The efficacy and safety of intravenous (IV) formulations of paracetamol, IV paracetamol, and IV propacetamol (a prodrug that is metabolized to paracetamol), compared with placebo and other analgesics, is unclear.

OBJECTIVES

To assess the efficacy and safety of IV formulations of paracetamol for the treatment of postoperative pain in both adults and children.

SEARCH METHODS

We ran the search for the previous review in May 2010. For this update, we searched the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 1), MEDLINE (May 2010 to 16 February 2016), EMBASE (May 2010 to 16 February 2016), LILACS (2010 to 2016), a clinical trials registry, and reference lists of reviews for randomized controlled trials (RCTs) in any language and we retrieved articles.

SELECTION CRITERIA

Randomized, double-blind, placebo- or active-controlled single dose clinical trials of IV paracetamol or IV propacetamol for acute postoperative pain in adults or children.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data, which included demographic variables, type of surgery, interventions, efficacy, and adverse events. We contacted study authors for additional information. We graded each included study for methodological quality by assessing risk of bias and employed the GRADE approach to assess the overall quality of the evidence.

MAIN RESULTS

We included 75 studies (36 from the original review and 39 from our updated review) enrolling a total of 7200 participants.Among primary outcomes, 36% of participants receiving IV paracetamol/propacetamol experienced at least 50% pain relief over four hours compared with 16% of those receiving placebo (number needed to treat to benefit (NNT) = 5; 95% confidence interval (CI) 3.7 to 5.6, high quality evidence). The proportion of participants in IV paracetamol/propacetamol groups experiencing at least 50% pain relief diminished over six hours, as reflected in a higher NNT of 6 (4.6 to 7.1, moderate quality evidence). Mean pain intensity at four hours was similar when comparing IV paracetamol and placebo, but was seven points lower on a 0 to 100 visual analog scale (0 = no pain, 100 = worst pain imaginable, 95% CI -9 to -6, low quality evidence) in those receiving paracetamol at six hours.For secondary outcomes, participants receiving IV paracetamol/propacetamol required 26% less opioid over four hours and 16% less over six hours (moderate quality evidence) than those receiving placebo. However, this did not translate to a clinically meaningful reduction in opioid-induced adverse events.Meta-analysis of efficacy comparisons between IV paracetamol/propacetamol and active comparators (e.g., opioids or nonsteroidal anti-inflammatory drugs) were either not statistically significant, not clinically significant, or both.Adverse events occurred at similar rates with IV paracetamol or IV propacetamol and placebo. However, pain on infusion occurred more frequently in those receiving IV propacetamol versus placebo (23% versus 1%). Meta-analysis did not demonstrate clinically meaningful differences between IV paracetamol/propacetamol and active comparators for any adverse event.

AUTHORS' CONCLUSIONS

Since the last version of this review, we have found 39 new studies providing additional information. Most included studies evaluated adults only. We reanalyzed the data but the results did not substantially alter any of our previously published conclusions. This review provides high quality evidence that a single dose of either IV paracetamol or IV propacetamol provides around four hours of effective analgesia for about 36% of patients with acute postoperative pain. Low to very low quality evidence demonstrates that both formulations are associated with few adverse events, although patients receiving IV propacetamol have a higher incidence of pain on infusion than both placebo and IV paracetamol.

Acetaminophen for analgesia following pyloromyotomy: does the route of administration make a difference?

Background

During the perioperative care of infants with hypertrophic pyloric stenosis, an opioid-sparing technique is often advocated due to concerns such as postoperative hypoventilation and apnea. Although the rectal administration of acetaminophen is commonly employed, an intravenous (IV) preparation is also currently available, but only limited data are available regarding IV acetaminophen use for infants undergoing pyloromyotomy. The objective of the current study was to compare the efficacy of IV and rectal acetaminophen for postoperative analgesia in infants undergoing laparoscopic pyloromyotomy.

Methods

A retrospective review of the use of IV and rectal acetaminophen in infants undergoing laparoscopic pyloromyotomy was performed. The efficacy was assessed by evaluating the perioperative need for supplemental analgesic agents, postoperative pain scores, tracheal extubation time, time in the postanesthesia care unit, time to oral feeding, and time to hospital discharge.

Results

The study cohort included 68 patients, of whom 34 patients received IV acetaminophen and 34 received rectal acetaminophen. All patients also received local infiltration of the surgical site with 0.25% bupivacaine. No intraoperative opioids were administered. There was no difference between the two groups with regard to postoperative pain scores, need for supplemental analgesic agents, time in the postanesthesia care unit, or time in the hospital. There was no difference in the number of children who tolerated oral feeds on the day of surgery or in postoperative complications.

Conclusion

Our preliminary data suggest that there is no clinical difference or advantage with the use of IV versus rectal acetaminophen in infants undergoing laparoscopic pyloromyotomy.

Benefits of Multimodal Enhanced Recovery Pathway in Patients Undergoing Open Ventral Hernia Repair

BACKGROUND

Use of Enhanced Recovery After Surgery (ERAS) pathways have evidenced improved outcomes in several surgical specialties. The effectiveness of ERAS pathways specific to hernia surgery, however, has not yet been investigated. We hypothesized that our ERAS pathway would accelerate functional recovery and shorten hospitalization in patients undergoing open ventral hernia repair (VHR).

STUDY DESIGN

Consecutive patients undergoing open major VHR using transversus abdominis release and sublay synthetic mesh placement, with use of our ERAS pathway, were compared with a historical cohort before ERAS implementation. Main outcomes measures were time to diet advancement, time to return of bowel function, time to oral narcotics, length of stay (LOS), and 90-day readmissions.

RESULTS

Between January 2014 and January 2015, 100 patients undergoing VHR with ERAS implementation were compared with a historical cohort. The ERAS group demonstrated significantly shorter times to liquid and regular diet: 1.1 vs 2.7 and 3.0 vs 4.8 days, respectively (p < 0.001). Furthermore, ERAS patients demonstrated significantly shorter times to flatus and bowel movement: 3.1 vs 3.9 and 3.6 vs 5.2 days, respectively (p < 0.001). Average LOS was reduced from 6.1 to 4.0 days (p < 0.001), and ERAS patients had significantly fewer 90-day readmissions, 4% vs 16% (p < 0.001).

CONCLUSIONS

A comprehensive ERAS pathway for major open VHR was implemented safely. Multimodal perioperative pain management, oral opioid-receptor blockade, and early feeding strategies resulted in accelerated intestinal recovery, shorter hospitalizations, and fewer readmissions. Use of our ERAS pathway appears to result in improved outcomes in patients undergoing open VHR.

Present-day challenges and future solutions in postoperative pain management: results from PainForum 2014

This paper is a summary of presentations on postoperative pain control by the authors at the 2014 PainForum meeting in People's Republic of China. Postoperative pain is often untreated or undertreated and may lead to subsequent chronic pain syndromes. As more procedures migrate to the outpatient setting, postoperative pain control will become increasingly more challenging. Evidence-based guidelines for postoperative pain control recommend pain assessment using validated tools on a consistent basis. In this regard, consistency may be more important than the specific tool selected. Many hospitals have introduced a multidisciplinary acute pain service (APS), which has been associated with improved patient satisfaction and fewer adverse events. Patient education is an important component of postoperative pain control, which may be most effective when clinicians chose a multimodal approach, such as paracetamol (acetaminophen) and opioids. Opioids are a mainstay of postoperative pain control but require careful monitoring and management of side effects, such as nausea, vomiting, dizziness, and somnolence. Opioids may be administered using patient-controlled analgesia systems. Protocols for postoperative pain control can be very helpful to establish benchmarks for pain management and assure that clinicians adhere to evidence-based standards. The future of postoperative pain control around the world will likely involve more and better established APSs and greater communication between patients and clinicians about postoperative pain. The changes necessary to implement and move forward with APSs is not a single step but rather one of continuous improvement and ongoing change.

Intravenous paracetamol for relief of pain during transrectal-ultrasound-guided biopsy of the prostate: A prospective, randomized, double-blind, placebo-controlled study

Transrectal-ultrasound-guided prostate biopsy (TRUS-PBx) is the standard procedure for diagnosing prostate cancer. The procedure does cause some pain and discomfort; therefore, an adequate analgesia is necessary to ensure patient comfort, which can also facilitate good-quality results. This prospective, randomized, double-blinded, placebo-controlled study aimed to determine if intravenous (IV) paracetamol can reduce the severity of pain associated with TRUS-PBx. The study included 104 patients, scheduled to undergo TRUS-PBx with a suspicion of prostate cancer, that were prospectively randomized to receive either IV paracetamol (paracetamol group) or placebo (placebo group) 30 minutes prior to TRUS-PBx. All patients had 12 standardized biopsy samples taken. Pain was measured using a 10-point visual analog pain scale during probe insertion, during the biopsy procedure, and 1 hour postbiopsy. All biopsies were performed by the same urologist, whereas a different urologist administered the visual analog pain scale. There were not any significant differences in age, prostate-specific antigen level, or prostate volume between the two groups. The pain scores were significantly lower during probe insertion, biopsy procedure, and 1 hour postbiopsy in the paracetamol group than in the placebo group. In conclusion, the IV administration of paracetamol significantly reduced the severity of pain associated with TRUS-PBx.

IV acetaminophen: Efficacy of a single dose for postoperative pain after hip arthroplasty: subset data analysis of 2 unpublished randomized clinical trials

Inadequate control of postoperative pain after orthopedic procedures may trigger complications that increase morbidity. Multimodal analgesia is used to manage pain effectively after surgical procedures and reduce the need for rescue analgesia. Intravenous (IV) acetaminophen (OFIRMEV; Cadence Pharmaceuticals, Inc.), an analgesic that has been studied and used in the multimodal management of acute pain after major orthopedic procedures, combines the safety seen with oral and rectal formulations with a preferred route of administration. Two double-blind, randomized, placebo-controlled clinical trials were conducted (total 130 patients) to determine the efficacy and safety of single-dose IV acetaminophen in patients following total hip arthroplasty. Although both studies were stopped prematurely, overlap in patient populations, study design, and methodologies in the single-dose phase of these studies allowed for analysis of their results to be presented concurrently. Both trials demonstrated IV acetaminophen having greater efficacy than placebo in terms of primary endpoints [pain intensity differences from T0.5 to T3 (P < 0.05 in both studies)]. The use of IV acetaminophen also reduced the need for rescue opioid consumption, with patients receiving IV acetaminophen consuming, on average, less than half the amount of rescue medication as those receiving placebo. IV acetaminophen was effective in treating moderate-to-severe pain after total hip arthroplasty and reduced the need for rescue opioid consumption.

Is Scheduled Intravenous Acetaminophen Effective in the Pain Management Protocol of Geriatric Hip Fractures?

BACKGROUND

Hip fractures have significant effects on the geriatric population and the health care system. Prior studies have demonstrated both the safety of intravenous (IV) acetaminophen and its efficacy in decreasing perioperative narcotic consumption. The purpose of this study is to evaluate the effect of scheduled IV acetaminophen for perioperative pain control on length of hospital stay, pain level, narcotic use, rate of missed physical therapy (PT) sessions, adverse effects, and discharge disposition in geriatric patients with hip fractures.

METHODS

A retrospective review was performed of all patients 65 years and older admitted to a level I trauma center, who received operative treatment for a hip fracture over a 2-year period. Demographic data, in-hospital variables, and outcome measures were analyzed. Three hundred thirty-six consecutive fractures in 332 patients met inclusion criteria. These patients were divided into 2 cohorts. Group 1 (169 fractures) consisted of patients treated before the initiation of a standardized IV acetaminophen perioperative pain control protocol, and group 2 (167 fractures) consisted of those treated after the protocol was initiated.

RESULTS

Group 2 had a statistically significant shorter mean length of hospital stay (4.4 vs 3.8 days), lower mean pain score (4.2 vs 2.8), lower mean narcotic usage (41.3 vs 28.3 mg), lower rate of PT sessions missed (21.8% vs 10.4%), and higher likelihood of discharge home (7% vs 19%; P ≤ .001). Use of IV acetaminophen was also consistently and independently predictive of the same variables (P < .01).

CONCLUSION

The utilization of scheduled IV acetaminophen as part of a standardized pain management protocol for geriatric hip fractures resulted in shortened length of hospital stay, decreased pain levels and narcotic use, fewer missed PT sessions, and higher rate of discharge to home.

LEVEL OF EVIDENCE

Therapeutic level III.

Multimodal Analgesia for Total Joint Arthroplasty

Optimal perioperative pain control for total joint arthroplasty remains a challenge. Whereas traditional regimens have relied heavily on opioids, newer multimodal pathways are increasingly gaining popularity as safer and more effective alternatives. The main premise of multimodal analgesia is decreased consumption of opioids, and hence lesser opioid-related adverse events. Other reported advantages include lower pain scores, faster functional recovery, higher patient satisfaction, and shorter length of hospital stay. Unfortunately, despite the advent of numerous analgesic techniques, the multimodal approach has remained widely variable, making direct comparison between studies difficult to interpret. This article provides an extensive review of traditional and modern perioperative interventions in pain management for total joint arthroplasty, including intravenous patient-controlled analgesia, epidural infusion, oral opioids, nonsteroidal anti-inflammatory drugs, acetaminophen, peripheral nerve blocks, periarticular infiltration, steroids, anticonvulsants, and long-acting local anesthetics. Emphasis is placed on pathophysiology, clinical evidence, and timing. A standardized multimodal analgesia protocol is also proposed based on best available evidence. In addition to pharmacologic interventions, patient education and interdisciplinary collaboration among the care teams play an important role in the success of any treatment pathway. With a growing demand for total joint arthroplasty in an era of bundled payments and accountable care, there has never been a greater need for a standardized multimodal analgesia pathway.

Perioperative nonopioid agents for pain control in spinal surgery

PURPOSE

Commonly used nonopioid analgesic agents that are incorporated into multimodal perioperative pain management protocols in spinal surgery are reviewed.

SUMMARY

Spinal procedures constitute perhaps some of most painful surgical interventions, as they often encompass extensive muscle dissection, tissue retraction, and surgical implants, as well as prolonged operative duration. Perioperative nonopioid analgesics frequently used in multimodal protocols include gabapentin, pregabalin, acetaminophen, dexamethasone, ketamine, and nonsteroidal antiinflammatory drugs (NSAIDs). There is evidence to suggest that gabapentin is safe and effective in reducing opioid consumption and pain scores at optimal doses of 600-900 mg orally administered preoperatively. Pregabalin 150-300 mg orally perioperatively has been shown to reduce both pain and narcotic consumption. Most reports concur that a single 1-g i.v. perioperative dose is safe in adults and that this dose has been shown to reduce pain and attenuate narcotic requirements. Dexamethasone's influence on postoperative pain has primarily been investigated for minor spinal procedures, with limited evidence for spinal fusions. Ketamine added to a patient-controlled analgesia regimen appears to be efficacious for 24 hours postoperatively when implemented for microdiskectomy and laminectomy procedures at doses of 1 mg/mL in a 1:1 mixture with morphine. For patients undergoing laminectomy or diskectomy, NSAIDs appear to be safe and effective in reducing pain scores and decreasing opioid consumption.

CONCLUSION

Preemptive analgesic therapy combining nonopioid agents with opioids may reduce narcotic consumption and improve patient satisfaction after spinal surgery. Such therapy should be considered for patients undergoing various spinal procedures in which postoperative pain control has been historically difficult to achieve.

Intravenous acetaminophen in bariatric surgery: effects on opioid requirements

BACKGROUND

Opioids are commonly used after bariatric surgery for pain control because of their potent analgesic effects. Nevertheless, the morbidly obese patient has increased risk for developing adverse effects produced by opioids (such as sedation, apnea, hypoxemia, ileus, and vomiting). Intravenous acetaminophen (IVA) has been evaluated in some specialties showing a reduction in opioid consumption. The purpose of this study was to evaluate the effect on opioid consumption when IVA is administered in bariatric surgery patients.

MATERIAL AND METHODS

A retrospective study was performed in patients who underwent bariatric surgery. Group A included those patients who received IVA perioperatively and group B those who did not. The amount of opioids administered was calculated and compared for each group.

RESULTS

Group A included 38 cases (44.7%) and group B included 47 cases (55.3%). A comparison was performed in terms of age (P = 0.349), body mass index (P = 0.311), gender (P = 0.890), American Society of Anesthesiologist score (P = 0.438), total surgical time (P = 0.497), perioperative complications (P = 0.786), number of procedures per surgeon (P = 0.08), and type of surgical procedure (P ≤ 0.01). Group A had a mean 24-h total opioid dose of 99.5 mg, whereas group B of 164.6 mg (P = 0.018). Group A received 39.5% less opioids than group B. A post hoc analysis determined a statistical power of 0.74.

CONCLUSIONS

IVA used perioperatively can decrease opioid consumption in patients after bariatric surgery. Randomized trials are needed to corroborate these results.

Approach to pain management in chronic opioid users undergoing orthopaedic surgery

Opioids are commonly used for the management of pain in patients with musculoskeletal disorders; however, national attention has highlighted the potential adverse effects of the use of opioid analgesia in this and other nonmalignant pain settings. Chronic opioid users undergoing orthopaedic surgery represent a particularly challenging patient population in regard to their perioperative pain control and outcomes. Preoperative evaluation provides an opportunity to estimate a patient's preoperative opioid intake, discuss pain-related fears, and identify potential psychiatric comorbidities. Patients using high levels of opioids may also require referral to an addiction specialist. Various regional blockade and pharmaceutical options are available to help control perioperative pain, and a multimodal pain management approach may be of particular benefit in chronic opioid users undergoing orthopaedic surgery.

Treatment of postoperative pain after total hip arthroplasty: comparison between metamizol and paracetamol as adjunctive to opioid analgesics-prospective, double-blind, randomised study

INTRODUCTION

Metamizole use has been limited because of its risk of agranulocytosis. However, more recent literature seems to support its safety. This prospective, randomised, double-blind study was conducted to compare the analgesic effects of intravenous metamizole or intravenous paracetamol in combination with morphine PCA during the first 24 h following total hip arthroplasty.

MATERIALS AND METHODS

One hundred ten consecutive patients were selected for study. The two study groups were (A) metamizole, (B) paracetamol. Postoperative pain therapy was provided by Morphine PCA pump. In the first treatment group (A group), all patients received intravenous metamizole 1.5 g every 8 h during the first 24 postoperative hours. In the second treatment group (B group), all patients received intravenous paracetamol 1 g every 8 h during the first 24 postoperative hours. Postoperative pain intensity was measured 1, 2, 3, 4, 6, 8, 10, 14, 18, 22 h after the end of surgery by a VAS.

RESULTS

Statistically significant differences in VAS pain values favoring metamizole were reported at 6-h (p = 0.038), 8-h (p = 0.036), 14-h (p = 0.011), 18-h (p < 0.001) and 22-h (p = 0.025) post-baseline. Mean cumulative pain values were 17.9 for metamizole and 30.6 for paracetamol.

CONCLUSIONS

In this study, we have also shown excellent efficacy of paracetamol and metamizole combined with opioids, but metamizole proved to be a better analgesic than paracetamol. It is also necessary to mention the financial aspect considering that intravenous paracetamol is about ten times more expensive than an equivalent analgesic doses of intravenous metamizole.

Pregabalin reduces opioid consumption and improves outcome in chronic pain patients undergoing total knee arthroplasty

INTRODUCTION

Recently, multimodal pain control has been used to manage postoperative pain in patients undergoing total knee arthroplasty (TKA). This approach combines numerous modalities, such as opioids, nonsteroidal anti-inflammatory drugs, local anesthetics, and acetaminophen, in an effort to reduce overall opioid consumption and also to provide better pain control. Gabapentinoids are a class of drugs that have been used as part of multimodal approach, and may be effective in patients who are previous users of chronic pain medication. The hypothesis of this study was that the addition of pregabalin reduces opioid consumption and/or improves pain after TKA, even in patients who are previous users of chronic pain medications.

METHODS

Using a prospectively collected database, 262 consecutive patients undergoing primary TKA between December 2011 and April 2012 were identified who received multimodal analgesia after surgery that included pregabalin. Using the same database, these patients were compared with 268 patients undergoing TKA from January to December 2010 who also received multimodal analgesia but were not given pregabalin. The clinical records of these patients were reviewed in detail to determine the incidence and nature of postoperative complications, opioid consumption, and visual analog scale (VAS) pain scores.

RESULTS

The incidence of respiratory, renal, and hemodynamic complications was significantly lower in the patients who received pregabalin. Gastrointestinal complications, which included nausea, were not significantly different between the groups. Patients receiving pregabalin had a lower average opioid consumption, and their minimum and maximum levels of opioid consumption were also reduced. Previous users of chronic pain medications had higher VAS scores but the same opioid consumption compared with those who were not previous users of chronic pain medications. No difference was seen in the maximum VAS scores between patients who received pregabalin and those who did not.

CONCLUSION

Pregabalin in the context of multimodal pain management may be associated with reduced opioid consumption and other medical complications in patients undergoing TKA, including previous users of chronic pain medications.

Intravenous paracetamol reduces postoperative opioid consumption after orthopedic surgery: a systematic review of clinical trials

Postoperative pain management is one of the most challenging jobs in orthopedic surgical population as it comprises of patients from extremes of ages and with multiple comorbidities. Though effective, opioids may contribute to serious adverse effects particularly in old age patients. Intravenous paracetamol is widely used in the postoperative period with the hope that it may reduce opioid consumption and produce better pain relief. A brief review of human clinical trials where intravenous paracetamol was compared with placebo or no treatment in postoperative period in orthopedic surgical population has been done here. We found that four clinical trials reported that there is a significant reduction in postoperative opioid consumption. When patients received an IV injection of 2 g propacetamol, reduction of morphine consumption up to 46% has been reported. However, one study did not find any reduction of opioid requirement after spinal surgery in children and adolescent. Four clinical trials reported better pain scores when paracetamol has been used, but other three trials denied. We conclude that postoperative intravenous paracetamol is a safe and effective adjunct to opioid after orthopedic surgery, but at present there is no data to decide whether paracetamol reduces opioid related adverse effects or not.