Post-operative pain control following arthroscopic rotator cuff repair: Intravenous acetaminophen versus interscalene brachial plexus block; A prospective randomized study

Background

With the increasing number of patients undergoing arthroscopic rotator cuff repair (ARCR), postoperative pain control in these patients has become an important issue. We investigated and compared post-operative pain relief with intravenous acetaminophen (IA) and interscalene brachial plexus block (IBPB) after ARCR.

Methods

This prospective study involved 66 consecutive patients who underwent ARCR in 2019-2020 at our hospital. Overall, 23 and 43 shoulders were assigned to the IA and IBPB groups, respectively. We evaluated the visual analog scale (VAS) pain scores at rest, during activity, and at night for the first 72 h postoperatively. We compared the results statistically between the groups. A p-value <0.05 was considered statistically significant.

Results

VAS scores for night pain in the IBPB group were significantly lower than those in the IA group for the first 24 h postoperatively (p = 0.017). In contrast, the same scores were significantly lower in the IA group than in the IBPB group at 72 h postoperatively (p = 0.024). Other scores were not significantly different between the groups.

Conclusions

IBPB provides superior night pain control during the first 24 h postoperatively, and IA provides superior night pain control at 72 h postoperatively. However, there were no significant differences in other pain scores between the two groups.

Effect of preoperative intravenous vs oral acetaminophen on postoperative opioid consumption in an enhanced recovery after surgery (ERAS) program in patients undergoing open gynecologic oncology surgery

OBJECTIVE

Both intravenous (IV) and oral acetaminophen provide effective opioid-sparing analgesia after surgery when used as part of a multimodal preemptive pain management strategy. The purpose of this study was to compare postoperative opioid consumption in patients undergoing open gynecologic oncology surgery who received preoperative IV vs oral acetaminophen within an enhanced recovery after surgery (ERAS) program.

METHODS

Retrospective data were collected on consecutive patients undergoing open gynecologic oncology surgery from May 1, 2016 to February 28, 2018 in patients receiving either 1 g IV or oral acetaminophen preoperatively. Patients were given a preoperative multimodal analgesia regimen including acetaminophen, celecoxib, pregabalin and tramadol. The primary outcomes were morphine equivalent daily doses (MEDD) on postoperative days (POD) 0 and 1. Secondary outcomes included highest patient-reported pain score in the post-anesthesia care unit (PACU) and intraoperative MEDD. Regression models adjusted by matched pairs were fit to estimate the average treatment effect of IV vs oral acetaminophen on MEDD.

RESULTS

Of 353 patients, 178 (50.4%) received IV acetaminophen and 175 (49.6%) received oral acetaminophen. When balancing across the matched samples, there was no difference in postoperative MEDD for POD 0 between the IV and oral acetaminophen groups (Beta = -1.11; 95% CI: -4.83 to 2.60; p = 0.56). On POD 1, there was no difference between the IV and oral groups (Beta = 2.24; 95% CI: -2.76 to 7.25; p = 0.38).

CONCLUSIONS

There was no difference in postoperative opioid consumption between patients receiving preoperative IV or oral acetaminophen within an ERAS program for patients undergoing open gynecologic oncology surgery.

Opioid-Sparing Effect of Liposomal Bupivacaine and Intravenous Acetaminophen in Colorectal Surgery

BACKGROUND

This study evaluated the opioid-sparing effect of liposomal bupivacaine and intravenous acetaminophen in colorectal surgery.

MATERIALS AND METHODS

This study was a retrospective, 2 × 2 factorial cohort conducted at an academic medical center from May 2016 to February 2018. Patients undergoing open or minimally invasive colorectal resection were included. Exclusion criteria were age <18 y, surgery after second hospital day, ostomy, and allergy to acetaminophen, opioids, or bupivacaine. Intraoperative liposomal bupivacaine and intravenous acetaminophen administration within 18 h after surgery were evaluated. The primary outcome was intravenous morphine milligram equivalents administered within 24 h after surgery. A linear regression model adjusted for American Society of Anesthesiologists score, enhanced recovery after surgery management, open surgery, opioid use before surgery, and height was used for the primary analysis.

RESULTS

Among 486 included patients, 193 received both liposomal bupivacaine and intravenous acetaminophen, 93 received liposomal bupivacaine only, 104 received intravenous acetaminophen only, and 96 did not receive either. On average, patients received 21 (SD = 31) morphine equivalents over 24 h. Intraoperative liposomal bupivacaine was associated with a reduction of morphine equivalents (adjusted change -11, 95% CI -17 to -6), but intravenous acetaminophen was not (2, 95% CI -3 to 7). Intraoperative liposomal bupivacaine was associated with a reduction of length of stay (adjusted change = -1.2 d, 95% CI -2.1 to -0.3), but intravenous acetaminophen was not (adjusted change = 1.5 d, 95% CI 0.7 to 2.2).

CONCLUSIONS

Liposomal bupivacaine was associated with a significant reduction of opioid use within 24 h after colorectal surgery, but intravenous acetaminophen was not.

Effectiveness of scheduled intravenous acetaminophen in the postoperative pain management of video-assisted thoracic surgery

PURPOSE

The scheduled administration of intravenous acetaminophen (scheduled-IV-AcA) is one of the more effective multimodal analgesic approaches for postoperative pain in abdominal/orthopedic surgeries. However, there is little evidence concerning scheduled-IV-AcA after general thoracic surgery, especially when limited to video-assisted thoracoscopic surgery (VATS). We investigated the efficacy of scheduled-IV-AcA administration in patients after undergoing VATS.

METHODS

Ninety-nine patients who underwent VATS lobectomy or segmentectomy via an 8-cm access window and 1 camera port were retrospectively reviewed by categorizing them into groups either with scheduled-IV-AcA (Group AcA: n = 29) or without it (Group non-AcA: n = 70). Group AcA received 1 g of IV-AcA every 6 h from the end of the operation until the end of POD2. Postoperative pain was measured using a numeric rating scale (NRS) three times per day until discharge.

RESULTS

NRS scores were significantly lower in Group AcA with motion (on POD1 to the first point of POD2) than in Group non-AcA. Group non-AcA was also more likely to use additional analgesics than Group AcA (39% vs. 17%, p = 0.058).

CONCLUSIONS

Scheduled-IV-AcA administration is a safe and effective multimodal analgesic approach in patients undergoing VATS pulmonary resection via an 8-cm access window.

Comparison of the postoperative analgesic efficacies of intravenous acetaminophen and fascia iliaca compartment block in hip fracture surgery: A randomised controlled trial

BACKGROUND

Managing pain during movement after hip fracture surgery is important for achieving earlier hip mobilisation and for preventing postoperative complications. In the present study, we tested the hypothesis that the fascia iliaca compartment block (FICB) would improve postoperative pain on movement compared with intravenous acetaminophen.

METHODS

In this prospective, randomised, controlled, parallel trial, patients were assigned to either the intravenous acetaminophen or the ultrasound-guided FICB group. Visual analog scale (VAS) pain scores were evaluated at 6, 9, 12, 18, 24 h, 2 days, and 7 days postoperatively. The primary outcome was VAS scores on movement at 24 h after surgery. The secondary outcomes were VAS scores on movement at the other time points, VAS scores at rest, the total number of rescue analgesics required and incidence of delirium during the first 24 h postoperatively, potential drug or block-related complications, and the time to first standing.

RESULTS

VAS scores on movement at 24 h after surgery were significantly lower in the FICB group than in the intravenous acetaminophen group [median (the 25th to 75th percentiles), 20 (10-30) vs 40 (30-53); P < 0.01]. The VAS scores on movement at any other time point and the scores at rest at 12 h after surgery were also significantly lower in the FICB group than in the intravenous acetaminophen group. The two groups did not differ in terms of the total number of rescue analgesics required or the incidence of delirium during the first 24 h postoperatively; complications; or the time to first standing.

CONCLUSIONS

FICB improved postoperative pain on movement compared with intravenous acetaminophen without increasing the complication rate. However, the total number of rescue analgesics required and the time to first standing were not significantly different between the two groups.

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.

Intraoperative Single-Dose Intravenous Acetaminophen for Postoperative Analgesia After Skin Laser Irradiation Surgery in Paediatric Patients: A Small Prospective Study

Objective

Acetaminophen is an analgesic that shows efficacy in postoperative pain relief in children. Many drugs such as opioids, non-steroidal anti-inflammatory drugs, and/or acetaminophen have been used in paediatric skin laser irradiation surgery for postoperative pain relief. However, acetaminophen has some advantages over opioids, and opioids are being used less often. We aimed to demonstrate the effectiveness of intravenous (IV) acetaminophen during surgery for postoperative pain in paediatric skin laser irradiation.

Methods

The present study is a small, prospective, double-blinded, randomized controlled trial. Paediatric patients (1-12 years old with an American Society of Anesthesiologists physical Status I and II), scheduled for skin laser irradiation for a nevus or haemangioma between October 2014 and April 2016 were randomized into the acetaminophen (n=9) and placebo (saline, n=8) groups. The observational face scale (FS) and the Behavioural Observational Pain Scale (BOPS) scores were recorded on emergence from anaesthesia, and 1, 2, and 4 hr post-surgery.

Results

Patient characteristics were not significantly different except with regard to the irradiation area and surgery time. The observational FS and BOPS scores of the acetaminophen group were lower than those of the placebo group; median (minimum-maximum) at each recording time: 1 (0-2) - 0 (0-2) - 0 (0-1) - 0 (0-2) vs. 2 (0-4) - 0 (0-2) - 0 (0-2) - 0 (0-1) and 1 (0-3) - 1 (0-3) - 1 (0-2) - 0 (0-1) vs. 2 (0-4) - 3 (0-5) - 1 (0-4) - 0 (0-3), p=0.07 and p=0.003, respectively. No differences in post-surgical analgesic use or adverse events were observed.

Conclusion

In this study, we showed that the IV acetaminophen group had lower observational FS and BOPS scores in the early postoperative period; however, further studies including a large number of patients are required to confirm our findings.

Acetaminophen clearance during ex vivo continuous renal replacement therapies

Intravenous acetaminophen is an adjuvant to opioid use in critically ill and surgical patients requiring continuous renal replacement therapy (CRRT). The objective of this study was to determine the ex vivo transmembrane clearance of intravenous acetaminophen during continuous hemofiltration and hemodialysis. Transmembrane clearance was assessed using a validated ex vivo bovine blood model for CRRT using an F8 or HF1400 hemodiafilter. Ultrafiltrate and dialysate flow rates were 1, 2, and 3 L/h. Urea and acetaminophen clearances were calculated and compared. Acetaminophen was readily cleared by continuous hemofiltration with both hemodiafilters. Acetaminophen clearance rates were 92-98% of ultrafiltrate production rates. Similarly, dialytic acetaminophen clearances approximated dialysate flow rates for both hemodiafilters. Acetaminophen is readily cleared by CRRT. Patients receiving CRRT and acetaminophen may require increased doses for adequate pain control.

Population pharmacokinetics of intravenous acetaminophen in Japanese patients undergoing elective surgery

INTRODUCTION

Intravenous (i.v.) acetaminophen is administered during surgery for postoperative analgesia. However, little information is available on the pharmacokinetics of i.v. acetaminophen in Japanese patients undergoing surgery under general anesthesia.

METHODS

The study was approved by the Institutional Review Board and registered at UMIN-CTR (UMIN000013418). Patients scheduled to undergo elective surgery under general anesthesia were enrolled after obtaining written informed consent. During surgery, 1 g of i.v. acetaminophen was administered over 15, 60, or 120 min. Acetaminophen concentrations (15 or 16 samples per case) were measured at time points from 0-480 min after the start of administration (liquid chromatography-mass spectrometry/tandem mass spectrometry; limit of quantitation 0.1 μg/mL). The predictive performance of three published pharmacokinetic models was evaluated. Population pharmacokinetics were also analyzed using a nonlinear mixed-effect model based on the NONMEM program.

RESULTS

Data from 12 patients who underwent endoscopic or lower limb procedures were analyzed (male/female = 7/5, median age 55 years, weight 63 kg). Anesthesia was maintained with remifentanil and propofol or sevoflurane. The pharmacokinetic model of i.v. acetaminophen reported by Würthwein et al. worked well. Using 185 datapoints, the pharmacokinetics of i.v. acetaminophen were described by a two-compartment model with weight as a covariate but not age, sex, or creatinine clearance. The median prediction error and median absolute prediction error of the final model were -1 and 10%, respectively.

CONCLUSION

A population pharmacokinetic model of i.v. acetaminophen in Japanese patients was constructed, with performance within acceptable ranges.

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.

Estimating the Effect of Intravenous Acetaminophen for Postoperative Pain Management on Length of Stay and Inpatient Hospital Costs

Introduction

The provision of safe, effective, cost-efficient perioperative inpatient acute pain management is an important concern among clinicians and administrators within healthcare institutions. Overreliance on opioid monotherapy in this setting continues to present health risks for patients and increase healthcare costs resulting from preventable adverse events. The goal of this study was to model length of stay (LOS), potential opioid-related complications, and costs for patients reducing opioid use and adding intravenous acetaminophen (IV APAP) for management of postoperative pain.

Methods

Data for this study were de-identified inpatient encounters from The Advisory Board Company across 297 hospitals from 2012–2014, containing 2,238,433 encounters (IV APAP used in 12.1%). Encounters for adults ≥18 years of age admitted for cardiovascular, colorectal, general, obstetrics and gynecology, orthopedics, or spine surgery were included. The effects of reducing opioids and adding IV APAP were estimated using hierarchical statistical models. Costs were estimated by multiplying modeled reductions in LOS or complication rates by observed average volumes for medium-sized facilities, and by average cost per day or per complication (LOS: US$2383/day; complications: derived from observed charges).

Results

Across all surgery types, LOS showed an average reduction of 18.5% (10.7–32.0%) for the modeled scenario of reducing opioids by one level (high to medium, medium to low, or low to none) and adding IV APAP, with an associated total LOS-related cost savings of $4.5 M. Modeled opioid-related complication rates showed similar improvements, averaging a reduction of 28.7% (5.4–44.0%) with associated cost savings of $0.2 M. In aggregate, costs decreased by an estimated $4.7 M for a medium-sized hospital. The study design demonstrates associations only and cannot establish causal relationships. The cost impact of LOS is modeled based on observed data.

Conclusions

This investigation indicates that reducing opioid use and including IV APAP for postoperative pain management has the potential to decrease LOS, opioid-related complication rates, and costs from a hospital perspective.

Funding

Mallinckrodt Pharmaceuticals.

IV Acetaminophen Results in Lower Hospital Costs and Emergency Room Visits Following Bariatric Surgery: a Double-Blind, Prospective, Randomized Trial in a Single Accredited Bariatric Center

BACKGROUND

Postoperative pain control in bariatric surgery is challenging, despite use of intravenous (IV) narcotics. IV acetaminophen is one pain control alternative.

OBJECTIVE

The aim of this study was to investigate the economic impact of IV acetaminophen in bariatric surgery and its effect on patients' pain, satisfaction, and hospital length of stay.

METHODS

In a randomized controlled trial, Group 1 (treatment) received IV acetaminophen plus IV narcotics 30 min before surgery, then medication plus IV narcotics/PO narcotics for the remaining 18 h. Group 2 (control) received IV normal saline plus IV/PO narcotics. Patients underwent laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (SG). Primary outcomes included direct hospital costs, length of stay, postoperative pain, and patient satisfaction. Secondary outcomes included indirect costs, rescue narcotics dosage, and 30-day outcomes.

RESULTS

Mean direct hospital cost in the treatment group (n = 50) was $3089.18 versus $2991.62 for the control group (n = 50) (p > 0.05). Pain scores did not differ significantly (p = 0.61). After adjusting for surgery type, there was no significant difference in length of stay (p = 0.95). Significantly more control group patients incurred surgery-related indirect costs (10 versus 2%, p < 0.05), with greater presentation to the emergency department (ED) for abdominal pain (5/50 versus 1/50), yielding higher total indirect costs ($39,293 versus $13,185).

CONCLUSIONS

Using IV acetaminophen for postoperative pain management produced notable indirect cost savings and reduced ED visits in the first 30 days postoperatively, with good safety and tolerance. Decreased statistical power may have accounted for certain non-significant findings.

The Comparison of Apotel plus Low Dose of Morphine and Full Dose of Morphine in Pain Relief in Patients with Acute Renal Colic

BACKGROUND

Renal colic is an acute flank pain which may radiate to the groin, lower abdomen, or external genitalia due to the passage of a urinary stones. Pain management is the most important task in emergency wards when a patient with renal colic attends. This study aims to compare intravenous acetaminophen plus a low dose of morphine with a full dose of morphine in renal colic.

METHODS

In present randomized clinical trial, 100 patients with confirmed renal colic were recruited from the Emergency Ward of Imam Reza Teaching Hospital affiliated to Tabriz University of Medical Sciences, Iran, during a one-year period. These patients randomly received either intravenous acetaminophen (Apotel, 1 g) plus a low dose of morphine (n = 50), or a high dose of morphine (5 mg) (n = 50). Visual analogue scale (VAS) was used for reporting pain during 35 minutes. Side effects and rescue analgesic demand were recorded after 30 minutes.

FINDINGS

The two groups were matched for the patients' age and gender. Intra-group analysis showed significant gradual decreases in pain intensity after 35 minutes for both groups. Inter-group analysis, however, did not show a significant difference between the two groups in this regard. There was no significant difference between the two groups in terms of side effects. The rate of rescue analgesic demand was 36% in the first and 40% in the second group (P = 0.68).

CONCLUSION

According to the results study, Apotel plus a low dose of morphine is at least as effective and safe as a full dose of morphine in patients with renal colic.

OFIRMEV: an old drug becomes new again

This was judged to be the first place winning submission for the American Dental Society of Anesthesiology Student Essay Award. Acetaminophen is an old drug that is now available in an intravenous formulation. Its advantages and disadvantages are reviewed, including its potential role in multimodal postoperative pain therapy.