Old Drug, New Route: A Systematic Review of Intravenous Acetaminophen After Adult Cardiac Surgery

Pain management after cardiac surgery via median sternotomy: A systematic review with procedure-specific postoperative pain management (PROSPECT) recommendations

BACKGROUND

Pain after cardiac surgery via median sternotomy can be difficult to treat, and if inadequately managed can lead to respiratory complications, prolonged hospital stays and chronic pain.

OBJECTIVES

To evaluate available literature and develop recommendations for optimal pain management after cardiac surgery via median sternotomy.

DESIGN

A systematic review using PROcedure-SPECific Pain Management (PROSPECT) methodology.

ELIGIBILITY CRITERIA

Randomised controlled trials and systematic reviews published in the English language until November 2020 assessing postoperative pain after cardiac surgery via median sternotomy using analgesic, anaesthetic or surgical interventions.

DATA SOURCES

PubMed, Embase and Cochrane Databases.

RESULTS

Of 319 eligible studies, 209 randomised controlled trials and three systematic reviews were included in the final analysis. Pre-operative, intra-operative and postoperative interventions that reduced postoperative pain included paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), intravenous magnesium, intravenous dexmedetomidine and parasternal block/infiltration.

CONCLUSIONS

The analgesic regimen for cardiac surgery via sternotomy should include paracetamol and NSAIDs, unless contraindicated, administered intra-operatively and continued postoperatively. Intra-operative magnesium and dexmedetomidine infusions may be considered as adjuncts particularly when basic analgesics are not administered. It is not clear if combining dexmedetomidine and magnesium would provide superior pain relief compared with either drug alone. Parasternal block/surgical site infiltration is also recommended. However, no basic analgesics were used in the studies assessing these interventions. Opioids should be reserved for rescue analgesia. Other interventions, including cyclo-oxygenase-2 specific inhibitors, are not recommended because there was insufficient, inconsistent or no evidence to support their use and/or due to safety concerns.

The impact of a postoperative multimodal analgesia pathway on opioid use and outcomes after cardiothoracic surgery

OBJECTIVE

The Enhanced Recovery after Surgery Cardiac Society recommends using multimodal analgesia (MMA) for postoperative pain however, evidence-based guidelines have yet to be established. This study examines the impact of a standardized postoperative MMA pathway in reducing opioid consumption and related complications after cardiothoracic surgery (CTS).

METHODS

Within a multicenter healthcare system, a postoperative MMA pathway was developed and implemented at two CTS intensive care units (ICU) while the other CTS ICU opted to maintain the existing opioid-based pathway. A retrospective chart review was conducted on patients admitted to a CTS ICU within this healthcare system after conventional coronary artery bypass grafting and/or valve surgery from September 1, 2018, to June 30, 2019. Comparative analysis was conducted on patients prescribed MMA versus those managed with an opioid-based pathway. The primary outcome was total opioid consumption, converted to morphine milligram equivalents, 72-h post-surgery. Secondary outcomes included mobility within one-day post-surgery, ICU length of stay (LOS), time to first bowel movement (BM), and time to first zero Richmond Agitation-Sedation Scale (RASS).

RESULTS

Seven hundred sixty-two adults were included for final analysis. The MMA group had a higher body mass index, higher percentage of females, were more likely classified as African American and had higher scores for risk-adjusted complications. General Linear Model analysis revealed higher opioid consumption in the MMA group (Est. 0.22, p < 0.0009); however, this was not statistically significant after adjusting for differences in fentanyl usage. The MMA group was more likely to have mobility within one-day post-surgery (OR 0.44, p < 0.0001), have longer time to first BM (OR 1.93, p = 0.0011), and longer time to first zero RASS (OR 1.62, p = 0.0071). The analgesia groups were not a predictor for ICU LOS.

CONCLUSIONS

Opioid consumption was not reduced secondary to this postoperative MMA pathway. The MMA group was more likely to have mobility within one-day post-surgery. Patients in the MMA group were also more likely to have prolonged time to first BM and first zero RASS. Development and evaluation of a perioperative MMA pathway should be considered.

The efficacy and safety of paracetamol for pain relief: an overview of systematic reviews

OBJECTIVE

To evaluate the efficacy and safety of paracetamol as an analgesic medication in a range of painful conditions.

STUDY DESIGN

Systematic review of systematic reviews of the analgesic effects of paracetamol in randomised, placebo-controlled trials. Conduct of systematic reviews was assessed with AMSTAR-2; confidence in effect estimates (quality of evidence) was assessed with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria.

DATA SOURCES

MEDLINE, EMBASE, PsycINFO, Cochrane Database of Systematic Reviews; systematic reviews published 1 January 2010 - 30 April 2020.

DATA SYNTHESIS

We extracted pain and adverse events outcomes from 36 systematic reviews that assessed the efficacy of paracetamol in 44 painful conditions. Continuous pain outcomes were expressed as mean differences (MDs; standardised 0-10-point scale); dichotomous outcomes were expressed as risk ratios (RRs). There is high quality evidence that paracetamol provides modest pain relief for people with knee or hip osteoarthritis (MD, -0.3 points; 95% CI, -0.6 to -0.1 points) and after craniotomy (MD, -0.8 points; 95% CI, -1.4 to -0.2 points); there is moderate quality evidence for its efficacy in tension-type headache (pain-free at 2 hours: RR, 1.3; 95% CI, 1.1-1.4) and perineal pain soon after childbirth (patients experiencing 50% pain relief: RR, 2.4; 95% CI, 1.5-3.8). There is high quality evidence that paracetamol is not effective for relieving acute low back pain (MD, 0.2 points; 95% CI, -0.1 to 0.4 points). Evidence regarding efficacy in other conditions was of low or very low quality. Frequency of adverse events was generally similar for people receiving placebo or paracetamol, except that transient elevation of blood liver enzyme levels was more frequent during repeated administration of paracetamol to patients with spinal pain (RR, 3.8; 95% CI, 1.9-7.4).

CONCLUSIONS

For most conditions, evidence regarding the effectiveness of paracetamol is insufficient for drawing firm conclusions. Evidence for its efficacy in four conditions was moderate to strong, and there is strong evidence that paracetamol is not effective for reducing acute low back pain. Investigations that evaluate more typical dosing regimens are required.

PROSPERO REGISTRATION

CRD42015029282 (prospective).

Acetaminophen and tramadol hydrochloride-loaded soft gelatin capsule: preparation, dissolution and pharmacokinetics in beagle dogs

The objective of this study was to develop a novel acetaminophen and tramadol hydrochloride-loaded soft capsule (ATSC) with enhanced bioavailability of tramadol. The ATSC was manufactured in a pilot-scale batch size with the capsule contents composed of tramadol, acetaminophen, PEG 400 and Capmul MCM at a weight ratio of 37.5:325:177.5:30. Moreover, its dissolution, stability and pharmacokinetics in beagle dogs were carried out compared to commercial tablet. The dissolved amounts of acetaminophen from the ATSC and commercial tablet were not significantly different. However, compared to the latter, the former had significantly higher dissolution rate of tramadol at the initial times. In beagle dogs, the ATSC provided no significant difference in plasma concentrations and AUC of acetaminophen than did the commercial tablet; however, it significantly improved those of tramadol compared to the other, indicating the enhanced oral bioavailability of tramadol. Compared to the commercial tablet, the ATSC had a larger AUC value for tramadol (55.27 ± 11.06 vs. 92.62 ± 21.52 h·ng/ml). In the accelerated long-term stability, the ATSC offered higher than 96% drug content of acetaminophen and tramadol, suggesting that it was stable for at least six months. Therefore, this ATSC would be a recommendable candidate with enhanced oral bioavailability and excellent stability.

Scheduled Prophylactic 6-Hourly IV AcetaminopheN to Prevent Postoperative Delirium in Older CaRdiac SurgicAl Patients (PANDORA): protocol for a multicentre randomised controlled trial

INTRODUCTION

Postoperative delirium is common among older cardiac surgery patients. Often difficult to predict and address prophylactically, delirium complicates the postoperative course by increasing morbidity and mortality as well as prolonging both hospital and intensive care unit (ICU) lengths of stay. Based on our pilot trial, we intend to study the effect of scheduled 6-hourly acetaminophen administration for 48 hours post-cardiac surgery with cardiopulmonary bypass (CPB) on the incidence of in-hospital delirium and long-term neurocognitive outcomes. Additionally, effect on duration and severity of delirium, rescue analgesic consumption, acute and chronic pain scores and lengths of hospital and ICU stay will also be explored.

METHODS AND ANALYSIS

This multicentre, randomised, placebo-controlled, quadruple-blinded trial will include 900 older (>60 years) cardiac surgical patients requiring CPB. Patients meeting the inclusion criteria and not meeting any exclusion criteria will be enrolled at seven centres across the USA with Beth Israel Deaconess Medical Center (BIDMC), Boston, as the central coordinating centre. Additional sites may be included to broaden or speed accrual. The primary outcome measure is the incidence of in-hospital delirium till day 30. Secondary outcomes include the duration and severity of in-hospital delirium, hospital and ICU lengths of stay, postoperative pain scores, postoperative rescue analgesic consumption, postoperative cognitive function and chronic sternal pain. Creation of a biorepository and the use of intraoperative-blinded electroencephalogram (EEG) and cerebral oximetry data will support exploratory endpoints to determine mechanistic predictors of postoperative delirium.

ETHICS AND DISSEMINATION

This trial is approved and centrally facilitated by the Institutional Review Board at BIDMC. An independent Data Safety and Monitoring Board is responsible for maintaining safety oversight. Protocol # 2019 P00075, V.1.4 (dated 20 October 2020).

TRIAL REGISTRATION NUMBER

NCT04093219.

Analgesic and Antibiotic Prescription Pattern among Dentists in Guangzhou: A Cross-Sectional Study

Aim

To assess the rational use of drugs and the pattern of prescribing of analgesics and antibiotics for dental management and the information given by dentists in Guangzhou to their patients about the use of these drugs.

Methods

A questionnaire was distributed to 225 dentists working in Guangzhou. The questionnaires consisted of open-ended questions and were given to dentists about analgesic and antibiotic use in dentistry. The questionnaires were analyzed, and absolute frequencies were expressed in the answers to each question. The cases, the analgesics, and the antibiotics recommended by the dentists for each case were determined by the frequency analysis method of descriptive statistics.

Results

Responses to the questionnaire were received from 164 (72.9%) dentists. Paracetamol and diclofenac were the most widely prescribed analgesics. It is also estimated that selective COX-2 inhibitors or opioid analgesics have not been administered by dentists. The antibiotics primarily used for treatment were amoxicillin and metronidazole, and amoxicillin was used for prophylaxis. While more than 80% of dentists indicated that they provided their patients with information on the use of antibiotics, the quality of the information was limited. Patients were primarily instructed by dentists to observe the dosage and dose intervals of the prescription drugs.

Conclusions

The results of the present study demonstrated that dentists most commonly prescribe paracetamol and diclofenac as analgesics, amoxicillin, and metronidazole for the therapy of periodontal, endodontic, and surgical procedures. The results also showed that dentists informed their patients inadequately about analgesic and antibiotic use.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparing the effects of ketorolac and Paracetamol on postoperative pain relief after coronary artery bypass graft surgery. A randomized clinical trial

Introduction

Pain management after coronary artery bypass graft (CABG) surgery remains challenging.

Objective

This study aimed to compare the effects of Ketorolac and Paracetamol on postoperative CABG pain relief.

Method

This double-blind randomized clinical trial study was conducted in Ahvaz, Iran, from September 2018–December 2019. Two consecutive groups of 60 patients undergoing elective on-pump coronary artery bypass graft surgery.

Intervention

The patients were divided into 0.5 mg/kg of ketorolac mg/dl and 10 mg/kg of Paracetamol after surgery for pain management. Primary outcomes were: visual analog pain scale (VAS) at the time point immediately after extubation (baseline) and at 6, 12, 24 and 48 h and the total dose of morphine consumption. Secondary outcomes included the hemodynamic variables, weaning time, chest tube derange, in-hospital mortality and myocardial infarction.

Statistical analysis: The data were analyzed using SPSS version 22(SPSS, Chicago, IL). The Mann-Whitney U-test was used to compare demographic data, VAS scores, vital signs, and side effects. Repeated measurements were tested within groups using Friedman’s ANOVA and the Wilcoxon rank-sum test. Values were expressed as means ± standard deviations. Statistical significance was defined as a p-value < 0.05.

Results

Compared with baseline scores, there were significant declines in VAS scores in both groups throughout the time sequence (P< 0.05). The statistical VAS score was slightly higher in the Paracetamol group at most time points, except for the time of 6 h. However, at 24 and 48 h, the VAS score in group Paracetamol was significantly higher than in group Ketorolac. There were no significant differences between groups about hemodynamic variables.

Conclusion

The efficacy of ketorolac is comparable to that of Paracetamol in postoperative CABG pain relief.

Trial registry

IRCT20150216021098N5. Registered at 2019-09-12.

Acetaminophen affects the survivor, pigmentation and development of craniofacial structures in zebrafish (Danio rerio) embryos

In spite of its toxic effects, N-acetyl-p-aminophenol (APAP), also commonly known as acetaminophen or paracetamol, is one of the most widely used analgesic and antipyretic agents. It can be obtained without a medical prescription. To test the effect over the zebrafish embryonic development, a Fish Embryo acute Toxicity (FET) test was carried out with acetaminophen to establish the range of concentrations that cause a harmful effect on the zebrafish development. Diminished pigmentation (in embryos treated from 0 h post-fertilization) and blockage of melanin synthesis (in larvae treated from 72 h post-fertilization) were detected, suggesting the involvement of this compound in the development of black pigment cells as described recently for human epidermal melanocytes. Morphological abnormalities such as aberrant craniofacial structures, pericardial edemas, and blood accumulation were also found. All these effects could be due to higher levels of apoptotic cells detected in treated embryos. Therefore, teratogenic effects of acetaminophen cannot be ruled out, and its wide use should be taken with caution.

Intravenous Acetaminophen Reduces Length of Stay Via Mediation of Postoperative Opioid Consumption After Posterior Spinal Fusion in a Pediatric Cohort

OBJECTIVES

Since approval of intravenous acetaminophen (IV APAP), its use has become quite common without strong positive evidence. Our goal was to determine the effect of IV APAP on length of hospital stay (LOS) via mediation of opioid-related side effects in pediatric patients.

MATERIALS AND METHODS

After Institutional Review Board approval, 114 adolescents undergoing posterior spinal fusion were prospectively recruited and managed postoperatively with patient-controlled analgesia and adjuvant therapy. Patients were divided into 2 groups based on the use of IV APAP: control (n=70) and treatment (n=44). Association of IV APAP use with opioid outcomes was analyzed using inverse probability of treatment weighting (IPTW)-adjusted propensity scores to balance the 2 groups for all significant covariates except postoperative opioid consumption. Mediation analysis was carried out for LOS with IV APAP as the independent variable and morphine consumption as the mediator.

RESULTS

Oral intake was delayed by ∼1 day (P<0.001) and LOS was 0.6 days longer in the control group (P=0.044). After IPTW, time to oral intake remained significantly longer in the control group (P=0.014). The mediation model with IPTW revealed a significant negative association between IV APAP and morphine consumption (P<0.001), which significantly increased LOS (P<0.003). IV APAP had a significant opioid-sparing effect associated with shorter LOS.

DISCUSSION

IV APAP hastens oral intake and is associated with decreased LOS in an adolescent surgery population likely through decreased opioid consumption. Through addition of IV APAP in this population, LOS may be decreased, an important implication in the setting of escalating health care costs.

Beyond Opioids for Pain Management in Adult Critically Ill Patients

Critically ill patients commonly experience pain, and the provision of analgesia is an essential component of intensive care unit (ICU) care. Opioids are the mainstay of pain management in the ICU but are limited by their adverse effects, risk of addiction and abuse, and recent drug shortages of injectable formulations. A multimodal analgesia approach, utilizing nonopioid analgesics as adjuncts to opioid therapy, is recommended since they may modulate the pain response and reduce opioid requirements by acting on multiple pain mediators. Nonopioid analgesics discussed in detail in this article are acetaminophen, α-2 receptor agonists, gabapentinoids, ketamine, lidocaine, and nonsteroidal anti-inflammatory drugs. This literature review describes the clinical pharmacology, supportive ICU and relevant non-ICU data, and practical considerations associated with the administration of nonopioid analgesics in critically ill adult patients.

Simultaneous determination of acetaminophen, pramipexole and carbamazepine by ZSM-5 nanozeolite and TiO2 nanoparticles modified carbon paste electrode

In this present paper, a simple voltammetric method has been reported for the simultaneous determination of acetaminophen (AC), pramipexole (PRX) and carbamazepine (CBZ) using ZSM-5 nanozeolite-TiO₂ nanoparticles composite modified carbon paste electrode (ZSM-5/TiO₂/CPE). X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) and N₂ adsorption-desorption isotherm were used to characterize the structure of synthesized ZSM-5 nanozeolite. Also, cyclic voltammetry (CV), choronoamperometry and differential pulse voltammetry (DPV) were used to investigate the performance of the modified electrode. The oxidation peak currents of AC, PRX and CBZ at the surface of ZSM-5/TiO₂/CPE were increased dramatically against CPE and their overpotentials decreased. Also, DPV method was used for the simultaneous determination of three drugs in ternary mixture. The effects of modifier amount, pH and scan rate were investigated on the electrochemical response of AC, PRX and CBZ oxidation. The diffusion coefficient, D, and the catalytic rate constant, k_cat, were estimated for the oxidation of AC, PRX and CBZ at the surface of modified electrode. Under the optimized experimental conditions, AC, PRX and CBZ give linear response over the range of 2.5-110, 0.6-105 and 6.0-97 μM, respectively. The detection limits were found to be 0.58, 0.38 and 1.04 μM (S/N = 3) for AC, PRX and CBZ, respectively. The fabricated electrode showed good stability, reproducibility and repeatability as well as high recovery. The practical application of the modified electrode was demonstrated by measuring the concentration of spiked AC, PRX and CBZ in human plasma as real sample. The proposed method is simple, rapid and inexpensive and can be utilized as a valuable analytical tool in quality control of the pharmaceutical industry.

The hemodynamic effects of intravenous paracetamol (acetaminophen) vs normal saline in cardiac surgery patients: A single center placebo controlled randomized study

The hemodynamic effects of intravenous (IV) paracetamol in patients undergoing cardiac surgery are unknown. We performed a prospective single center placebo controlled randomized study with parallel group design in adult patients undergoing elective cardiac surgery. Participants received paracetamol (1 gram) IV or placebo (an equal volume of 0.9% saline) preoperatively followed by two postoperative doses 6 hours apart. The primary endpoint was the absolute change in systolic (SBP) 30 minutes after the preoperative infusion, analysed using an ANCOVA model. Secondary endpoints included absolute changes in mean arterial pressure (MAP) and diastolic blood pressure (DPB), and other key hemodynamic variables after each infusion. All other endpoints were analysed using random-effect generalized least squares regression modelling with individual patients treated as random effects. Fifty participants were randomly assigned to receive paracetamol (n = 25) or placebo (n = 25). Post preoperative infusion, paracetamol decreased SBP by a mean (SD) of 13 (18) mmHg, p = 0.02, compared to a mean (SD) of 1 (11) mmHg with saline. Paracetamol decreased MAP and DBP by a mean (SD) of 9 (12) mmHg and 8 (9) mmHg (p = 0.01 and 0.02), respectively, compared to a mean (SD) of 1 (8) mmHg and 0 (6) mmHg with placebo. Postoperatively, there were no significant differences in pressure or flow based hemodynamic parameters in both groups. This study provides high quality evidence that the administration of IV paracetamol in patients undergoing cardiac surgery causes a transient decrease in preoperative blood pressure when administered before surgery but no adverse hemodynamic effects when administered in the postoperative setting.