Single dose intravenous propacetamol or intravenous paracetamol for postoperative pain

A study of the regional differences in propacetamol-related adverse events using VigiBase data of the World Health Organization

Upon withdrawal of propacetamol, an injectable formulation of the paracetamol prodrug, in Europe due to safety concerns, South Korea's regulatory body requested a post-marketing surveillance study exploring its safety profile. We characterized regional disparities in adverse events (AE) associated with propacetamol between Asia and Europe using the World Health Organization's pharmacovigilance database, VigiBase. We performed disproportionality analyses using reporting odds ratios (rOR) and information component (IC) to determine whether five AEs (anaphylaxis, Stevens-Johnson syndrome, thrombosis, contact dermatitis/eczema, injection site reaction [ISR]) were associated with propacetamol versus non-propacetamol injectable antipyretics in Asia and Europe, separately. In Asia, there was a high reporting ratio of propacetamol-related ISR (rOR 5.72, 95% CI 5.19-6.31; IC₀₂₅ 1.27), satisfying the signal criteria; there were no reports of thrombosis and contact dermatitis/eczema. Two signals were identified in Europe, with higher reporting ratios for thrombosis (rOR 7.45, 95% CI 5.19-10.71; IC₀₂₅ 1.92) and contact dermatitis/eczema (rOR 16.73, 95% CI 12.48-22.42; IC₀₂₅ 2.85). Reporting ratios of propacetamol-related anaphylaxis were low for Asia and Europe. While signals were found for thrombosis and contact dermatitis/eczema in Europe, these were not detected in Asia. These findings suggest potential ethnic differences in propacetamol-related AEs between Asia and Europe, which could serve as supportive data for future decision-making.

Effect of Intravenous Paracetamol on Opioid Consumption in Multimodal Analgesia After Lumbar Disc Surgery: A Meta-Analysis of Randomized Controlled Trials

Background: Intravenous paracetamol, as an adjunct to multimodal analgesia, has been shown to successfully reduce opioid consumption after joint arthroplasty, abdominal surgery, and caesarean delivery. However, there are limited data on the opioid-sparing effect of intravenous paracetamol on lumbar disc surgery.

Objectives: The aim of this study was to investigate the effectiveness and safety of intravenous paracetamol for reducing opioid consumption in lumbar disc surgery. The primary outcome was cumulative opioid consumption within 24 h postoperatively.

Method: We followed the PRISMA-P guidelines and used GRADE to assess the quality of evidence. The review was registered in PROSPERO under the registration number CRD42021288168. Two reviewers conducted electronic searches in PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, and Web of Science (Clarivate Analytics). Randomized controlled trials (RCTs) that compared the postoperative opioid consumption of intravenous paracetamol with placebo in lumbar discectomy were included.

Results: Five trials comprising a total of 271 patients were included. The overall opioid consumption within 24 h postoperatively was reduced [mean difference (MD), −10.61 (95% CI, −16.00 to −5.22) mg, p = 0.0001, I² = 90%] in patients with intravenous paracetamol. Intravenous paracetamol significantly reduced the postoperative pain scores at 1 h [MD, −2.37 (95%CI, −3.81 to −0.94), p = 0.001, I² = 82%], 2 h [MD, −3.17 (95%CI, −3.85 to −2.48), p < 0.00001, I² = 38%], 6 h [MD, −1.75 (95%CI, −3.10 to −0.40), p = 0.01], 12 h [MD, −0.96 (95%CI, −1.77 to −0.15), p = 0.02], and 24 h [MD, −0.97 (95%CI, −1.67 to −0.27), p = 0.006] compared with the placebo. There were no differences in postoperative adverse effects.

Conclusion: Intravenous paracetamol reduced postoperative opioid consumption and decreased postoperative pain scores without increasing adverse effects. The overall GRADE quality of the evidence was rated as low to moderate. Intravenous paracetamol appears to be an applicable option as an important part of multimodal analgesia for postoperative analgesia after lumbar disc surgery.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/, CRD42021288168.

The Efficacy of Acetominophen for Total Laparoscopic Hysterectomy

OBJECTIVE

Despite limited data, acetaminophen, along with other agents, is commonly included in enhanced recovery after surgery (ERAS) protocols following laparoscopic hysterectomy. We aimed to systematically review the efficacy of acetaminophen on the management of postoperative pain after laparoscopic hysterectomy.

METHODS

We searched PubMed, SCOPUS, Web of Science, and Cochrane Library databases for relevant clinical trials investigating the role of acetaminophen in the management of pain after laparoscopic hysterectomy. We performed the risk of bias according to Cochrane's risk of bias tool. We performed the analysis of homogeneous data under the fixed-effects model during the analysis of heterogeneous data under the random-effects model. The primary outcome was the assessment of pain score after 2, 6, 12, and 24 h.

RESULTS

A total of 495 patients in 13 trials were included in our meta-analysis. Acetaminophen was not superior at reducing postoperative pain scores. Further analysis at progressive temporal points revealed no further significance; effect size at after 2 h (SMD = -0.020, 95% CI (-0.216; 0.176)), 6 h (SMD = -0.115, 95% CI (-0.312; 0.083)), 12 h (SMD = -0.126, 95% CI (-0.277; 0.025)), or 24 h (SMD = 0.063, 95% CI (-0.065; 0.191)). Pooled analysis was heterogeneous (P < 0.1); therefore, we conducted a sensitivity analysis yielding homogeneous results. The drug did not reduce opioid need (MD = -0.16, 95% CI (-2.39, 2.06), P = 0.89).

CONCLUSION

We conclude that acetaminophen is not beneficial for reducing pain after laparoscopic hysterectomy. Other alternatives have better results. Caution should be given to the inclusion of acetaminophen in ERAS protocols designed for laparoscopic hysterectomy, especially as a single agent or to reduce opioid consumption.

Paracetamol (acetaminophen) for prevention or treatment of pain in newborns

BACKGROUND

Newborn infants have the ability to experience pain. Hospitalised infants are exposed to numerous painful procedures. Healthy newborns are exposed to pain if the birth process consists of assisted vaginal birth by vacuum extraction or by forceps and during blood sampling for newborn screening tests.

OBJECTIVES

To determine the efficacy and safety of paracetamol for the prevention or treatment of procedural/postoperative pain or pain associated with clinical conditions in neonates. To review the effects of various doses and routes of administration (enteral, intravenous or rectal) of paracetamol for the prevention or treatment of pain in neonates.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 4), MEDLINE via PubMed (1966 to 9 May 2016), Embase (1980 to 9 May 2016), and CINAHL (1982 to 9 May 2016). We searched clinical trials' databases, Google Scholar, conference proceedings, and the reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials of paracetamol for the prevention/treatment of pain in neonates (≤ 28 days of age).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from the articles using pre-designed forms. We used this form to decide trial inclusion/exclusion, to extract data from eligible trials and to request additional published information from authors of the original reports. We entered and cross-checked data using RevMan 5 software. When noted, we resolved differences by mutual discussion and consensus. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included nine trials with low risk of bias, which assessed paracetamol for the treatment of pain in 728 infants. Painful procedures studied included heel lance, assisted vaginal birth, eye examination for retinopathy of prematurity assessment and postoperative care. Results of individual studies could not be combined in meta-analyses as the painful conditions, the use of paracetamol and comparison interventions and the outcome measures differed. Paracetamol compared with water, cherry elixir or EMLA cream (eutectic mixture of lidocaine and prilocaine) did not significantly reduce pain following heel lance. The Premature Infant Pain Profile score (PIPP) within three minutes following lancing was higher in the paracetamol group than in the oral glucose group (mean difference (MD) 2.21, 95% confidence interval (CI) 0.72 to 3.70; one study, 38 infants). Paracetamol did not reduce "modified facies scores" after assisted vaginal birth (one study, 119 infants). In another study (n = 123), the Échelle de Douleur et d'Inconfort du Nouveau-Né score at two hours of age was significantly higher in the group that received paracetamol suppositories than in the placebo suppositories group (MD 1.00, 95% CI 0.60 to 1.40). In that study, when infants were subjected to a heel lance at two to three days of age, Bernese Pain Scale for Neonates scores were higher in the paracetamol group than in the placebo group, and infants spent a longer time crying (MD 19 seconds, 95% CI 14 to 24). For eye examinations, no significant reduction in PIPP scores in the first or last 45 seconds of eye examination was reported, nor at five minutes after the eye examination. In one study (n = 81), the PIPP score was significantly higher in the paracetamol group than in the 24% sucrose group (MD 3.90, 95% CI 2.92 to 4.88). In one study (n = 114) the PIPP score during eye examination was significantly lower in the paracetamol group than in the water group (MD -2.70, 95% CI -3.55 to 1.85). For postoperative care following major surgery, the total amount of morphine (µg/kg) administered over 48 hours was significantly less among infants assigned to the paracetamol group than to the morphine group (MD -157 µg/kg, 95% CI -27 to -288). No adverse events were noted in any study. The quality of evidence according to GRADE was low.

AUTHORS' CONCLUSIONS

The paucity and low quality of existing data do not provide sufficient evidence to establish the role of paracetamol in reducing the effects of painful procedures in neonates. Paracetamol given after assisted vaginal birth may increase the response to later painful exposures. Paracetamol may reduce the total need for morphine following major surgery, and for this aspect of paracetamol use, further research is needed.

The prescription opioid crisis: role of the anaesthesiologist in reducing opioid use and misuse

Reports of strategies to prevent and treat the opioid epidemic are growing. Significant attention has been paid to the benefits of opioid addiction research, clinical prescribing, and public policy initiatives in curbing the epidemic. However, the role of the anaesthesiologist in minimising opioid use and misuse remains underexplored. For many patients with an opioid use disorder, the perioperative period represents the source of initial exposure. As perioperative physicians, anaesthesiologists are in the unique position to manage pain effectively while simultaneously decreasing opioid consumption. Multiple opportunities exist for anaesthesiologists to minimise opioid exposure and prevent subsequent persistent opioid use. We present a global strategy for decreasing perioperative opioid use and misuse among surgical patients. A historical perspective of the opioid epidemic is presented, together with an analysis of opioid supply and demand forces. We then present specific temporal strategies for opioid use reduction in the perioperative period. We emphasise the importance of preoperative identification of patients at risk for long-term opioid use and misuse, review the evidence supporting the opioid sparing capacity of individual multimodal analgesic agents, and discuss the benefits of regional anaesthesia for minimising opioid consumption. We describe postoperative and post-discharge tools, including effective multimodal analgesia and the role of a transitional pain service. Finally, we offer general institutional strategies that can be led by anaesthesiologists, identify gaps in knowledge, and offer directions for future research.

Effect of intravenous acetaminophen versus fentanyl on postoperative pain after transurethral lithotripsy

Background

Postoperative pain is the most common postoperative complication. This study was conducted to assess the effect of acetaminophen versus fentanyl on postoperative pain relief in patients who underwent urologic surgeries.

Methods

This clinical trial was conducted on patients aged 18–65 years. Patients were randomly assigned to receive either 2000 mg acetaminophen (propacetamol) or 2 mcg.kg⁻¹ fentanyl intravenously, 15 min before the end of surgery. The postoperative pain was evaluated every 6 h for 24 h using the Visual Analog Scale. Total morphine dose taken in 24 h and hemodynamic status were evaluated.

Results

Eighty patients were enrolled into the trial. The mean score of pain in 6, 12, 18, and 24 h after surgery was lower in the acetaminophen group than in the fentanyl group but the difference was not statistically significant except in 12 and 18 h after surgery (p < 0.05). The amount of administered morphine was higher in the fentanyl group than in the acetaminophen group, but the difference was not statistically significant. The hemodynamic status including systolic and diastolic blood pressure and heart rates were nearly the same in the two groups but the SpO₂ mean was significantly higher in the acetaminophen group than the fentanyl group.

Conclusions

This trial indicated that intravenous acetaminophen is as effective as intravenous fentanyl in pain relief after urologic surgeries (transurethral lithotripsy).

Analgesic Effects of Intravenous Acetaminophen vs Placebo for Endoscopic Sinus Surgery and Postoperative Pain: A Randomized Clinical Trial

Importance

Intravenous acetaminophen is a commonly prescribed analgesic for the prevention and treatment of postsurgical pain. Its efficacy in the context of endoscopic sinus surgery (ESS) has yielded mixed results.

Objective

To compare the efficacy of perioperative intravenous acetaminophen (IVAPAP) with that of placebo in improving early postoperative pain after endoscopic sinus surgery (ESS).

Design, Setting, and Participants

A prospective, randomized clinical trial including 62 patients undergoing ESS for chronic rhinosinusitis in a single tertiary referral hospital.

Interventions

Participants were randomized to receive 1 g of IVAPAP or 100 mL of placebo consisting of saline infusions immediately before the start of surgery and 4 hours after the initial dose.

Main Outcomes and Measures

The primary outcome was postoperative pain measured by visual analog scale (VAS) scores up to 24 hours after surgery by blinded observers. Secondary endpoints included postoperative opioid (intravenous and oral) use and adverse events in the 24-hour postoperative period.

Results

Of the 62 enrolled adult participants, 60 were randomized (31 to IVAPAP intervention and 29 to placebo). The mean (SD) age of participants was 53.7 (14.7) years and 35 (58%) of the participants were men and 25 (42%) were women. Within the first hour, mean pain scores were reduced in the IVAPAP group compared with the control group, reaching a maximum difference of 7.7 mm on a VAS scale favoring the treatment group with a true difference possibly as high as 22 mm, and the data are compatible with a clinically meaningful difference. At 12- and 24-hours, average pain scores were less in the placebo group and the data are compatible with a clinically meaningful difference of 5.8 (-5.2 to 16.8) and 8.2 (-1.9 to 18.4), respectively, favoring the placebo group. However, at all time points the CIs included the null value and were wide, thus preventing definitive conclusions. Inspection of the secondary outcomes favored IVAPAP, but the wide range of the CIs and inclusion of the null value prevent definitive conclusions.

Conclusions and Relevance

The results of this study are inconclusive. The data suggest that perioperative intravenous acetaminophen may reduce immediate postoperative pain and opioid requirements compared with placebo and these differences could be clinically meaningful. Unfortunately, the imprecision of the estimates prevents definitive conclusion. Use of IVAPAP does not seem to increase adverse events.

Trial Registration

clinicaltrials.gov Identifier: NCT01608308.

Randomized Trial of Adding Parenteral Acetaminophen to Prochlorperazine and Diphenhydramine to Treat Headache in the Emergency Department

Introduction

Headaches represent over three million emergency department (ED) visits per year, comprising 2.4% of all ED visits. There are many proposed methods and clinical guidelines of treating acute headache presentations. However, data on intravenous acetaminophen usage in these settings are lacking. In this study, we sought to determine the efficacy of intravenous (IV) acetaminophen as an adjunct to a standard therapy for the treatment of patients who present to the ED with a chief complaint of “headache.”

Methods

We conducted a single site, randomized, double-blind, placebo-controlled trial investigating the clinical efficacy of IV acetaminophen as an adjunct to a standard therapy with prochlorperazine and diphenhydramine for the treatment of patients who present to the ED with a chief complaint of “headache” or variants thereof. (See below for variants). The primary outcome measure of the efficacy of parenteral acetaminophen as an adjunct treatment for headache in addition to a standard therapy was a threshold two-point reduction in visual analog scale (VAS) pain scores on a 1–10 level at 90 minutes. Secondary outcomes measures included assessment of decreased requirement of “rescue” pain medicines, defined as any analgesic medications outside of diphenhydramine, prochlorperazine and acetaminophen, with particular interest to potential opioid-sparing effects with parenteral acetaminophen. Additional secondary outcome measure included time to disposition from arrival in the ED.

Results

For the acetaminophen group the initial mean pain score was 8.67, for the placebo group 8.61. At 90 minutes pain score was 2.23 for the acetaminophen group and 3.99 for placebo (p<0.01, 95% confidence interval (CI) [0.8%–16%]. Of 45 patients in each group, we observed at least a threshold two-point decrease in pain score 36/45 (80%) with acetaminophen vs. 25/45 (55%) with placebo (p <0.01) 95% CI [5%–41%], number needed to treat (NNT) = 4). Secondary outcome measure did not demonstrate a difference in length of stay (161 minutes for acetaminophen arm and 159 minutes for placebo). However, 17/45 (38%) of patients who received IV acetaminophen required rescue analgesia, opposed to 24/45 (53%) of patients in the placebo group (p=0.13) 95% CI [−5%–34%].

Conclusion

IV acetaminophen when used with prochlorperazine and diphenhydramine to treat acute headaches in the ED resulted in statistically significant pain reduction compared with prochlorperazine and diphenhydramine alone as measured by both threshold of lowering VAS pain score by at least two points (NNT = 4) and overall decline in VAS pain score. Further study is required to validate these results.

Adverse effect profile comparison of pain regimens with and without intravenous acetaminophen in total hip and knee arthroplasty patients

Background:

The use of adjunct, non-opioid agents is integral for pain control following total hip and knee arthroplasty. Literature comparing safety profiles of intravenous acetaminophen versus opioids is lacking.

Objective:

To determine whether there is a difference in frequency and type of adverse effects between intravenous acetaminophen–treated and non-intravenous acetaminophen–treated patients. Primary safety endpoints included any adverse effect noted in the electronic medical record post-surgically. Secondary endpoints included changes in laboratory values, vital signs, and pain scores.

Methods:

This is a retrospective, matched, cohort study with data collected from electronic medical records. Adverse effects were collected from progress notes, nursing notes, and post-operative notes. Mean pain score was measured by the 11-point visual analog scale over a 72-h period.

Results:

A total of 609 patients who underwent a total hip or knee replacement were included. In all, 406 patients were treated with intravenous acetaminophen, and 203 patients received medication management without intravenous acetaminophen. More patients treated with intravenous acetaminophen experienced an adverse effect compared to patients who did not receive intravenous acetaminophen (91.63% versus 84.73%; p = 0.012). Mean cumulative acetaminophen exposure was similar in the intravenous acetaminophen group (7704.89 ± 2558.6 versus 7260.1 ± 3016.09 mg; p = 0.07). Mean opioid use was similar in the intravenous acetaminophen group as compared to the non-intravenous acetaminophen group (209.61 ± 555.09 versus 163.89 ± 232.44 mg; p = 0.152). Significantly higher mean pain scores were found in the intravenous acetaminophen group during the 72-h post-surgery period as compared with non-intravenous acetaminophen-treated patients.

Conclusion:

The increased utilization of intravenous acetaminophen in multimodal pain management did not result in an improved safety or tolerability profile or reduced opioid utilization in orthopedic patients.

Chronic Pain in Neurosurgery

This review includes a summary of contemporary theories of pain processing and advocates a multimodal analgesia approach for providing perioperative care. A summary of various medication classes and anesthetic techniques is provided that highlights evidence emerging from neurosurgical literature. This summary covers opioid management, acetaminophen, nonsteroidal antiinflammatories, ketamine, lidocaine, dexmedetomidine, corticosteroids, gabapentin, and regional anesthesia for neurosurgery. At present, there is not enough investigation into these areas to describe best practices for treating or preventing chronic pain in neurosurgery; but providers can identify a wider range of options available to personalize perioperative care strategies.

Clinical update on benefit versus risks of oral paracetamol alone or with codeine: still a good option?

BACKGROUND

After decades of worldwide use of paracetamol/acetaminophen as a popular and apparently safe prescription and over-the-counter medicine, the future role of this poorly understood analgesic has been seriously questioned by recent concerns about prenatal, cardiovascular (CV) and hepatic safety, and also about its analgesic efficacy. At the same time the usefulness of codeine in combination products has come under debate.

METHODS

Based on a PubMed database literature search on the terms efficacy, safety, paracetamol, acetaminophen, codeine and their combinations up to and including June 2016, this clinical update reviews the current evidence of the benefit and risks of oral paracetamol alone and with codeine for mild-to-moderate pain in adults, and compares the respective efficacy and safety profiles with those of nonsteroidal anti-inflammatory drugs (NSAIDs).

RESULTS

Whereas there is a clear strong association of NSAID use and gastrointestinal (GI) and CV morbidity and mortality, evidence for paracetamol with and without codeine supports the recommended use even in most vulnerable individuals, such as the elderly, pregnant women, alcoholics, and compromised GI and CV patients. The controversies and widespread misconceptions about the complex hepatic metabolism and potential hepatotoxicity have been corrected by recent reviews, and paracetamol remains the first-line nonopioid analgesic in patients with liver diseases if notes of caution are applied.

CONCLUSION

Due to its safety and tolerability profile paracetamol remained a first-line treatment in many international guidelines. Alone and with codeine it is a safe and effective option in adults, whilst NSAIDs are obviously less safe as alternatives, given the risk of potentially fatal GI and CV adverse effects.

Paracetamol (acetaminophen) for prevention or treatment of pain in newborns

BACKGROUND

Newborn infants have the ability to experience pain. Hospitalised infants are exposed to numerous painful procedures. Healthy newborns are exposed to pain if the birth process consists of assisted vaginal birth by vacuum extraction or by forceps and during blood sampling for newborn screening tests.

OBJECTIVES

To determine the efficacy and safety of paracetamol for the prevention or treatment of procedural/postoperative pain or pain associated with clinical conditions in neonates. To review the effects of various doses and routes of administration (enteral, intravenous or rectal) of paracetamol for the prevention or treatment of pain in neonates.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 4), MEDLINE via PubMed (1966 to 9 May 2016), Embase (1980 to 9 May 2016), and CINAHL (1982 to 9 May 2016). We searched clinical trials' databases, Google Scholar, conference proceedings, and the reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials of paracetamol for the prevention/treatment of pain in neonates (≤ 28 days of age).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from the articles using pre-designed forms. We used this form to decide trial inclusion/exclusion, to extract data from eligible trials and to request additional published information from authors of the original reports. We entered and cross-checked data using RevMan 5 software. When noted, we resolved differences by mutual discussion and consensus. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included nine trials with low risk of bias, which assessed paracetamol for the treatment of pain in 728 infants. Painful procedures studied included heel lance, assisted vaginal birth, eye examination for retinopathy of prematurity assessment and postoperative care. Results of individual studies could not be combined in meta-analyses as the painful conditions, the use of paracetamol and comparison interventions and the outcome measures differed. Paracetamol compared with water, cherry elixir or EMLA cream (eutectic mixture of lidocaine and prilocaine) did not significantly reduce pain following heel lance. The Premature Infant Pain Profile score (PIPP) within three minutes following lancing was higher in the paracetamol group than in the oral glucose group (mean difference (MD) 2.21, 95% confidence interval (CI) 0.72 to 3.70; one study, 38 infants). Paracetamol did not reduce "modified facies scores" after assisted vaginal birth (one study, 119 infants). In another study (n = 123), the Échelle de Douleur et d'Inconfort du Nouveau-Né score at two hours of age was significantly higher in the group that received paracetamol suppositories than in the placebo suppositories group (MD 1.00, 95% CI 0.60 to 1.40). In that study, when infants were subjected to a heel lance at two to three days of age, Bernese Pain Scale for Neonates scores were higher in the paracetamol group than in the placebo group, and infants spent a longer time crying (MD 19 seconds, 95% CI 14 to 24). For eye examinations, no significant reduction in PIPP scores in the first or last 45 seconds of eye examination was reported, nor at five minutes after the eye examination. In one study (n = 81), the PIPP score was significantly higher in the paracetamol group than in the 24% sucrose group (MD 3.90, 95% CI 2.92 to 4.88). In one study (n = 114) the PIPP score during eye examination was significantly lower in the paracetamol group than in the water group (MD -2.70, 95% CI -3.55 to 1.85). For postoperative care following major surgery, the total amount of morphine (µg/kg) administered over 48 hours was significantly less among infants assigned to the paracetamol group than to the morphine group (MD -157 µg/kg, 95% CI -27 to -288). No adverse events were noted in any study. The quality of evidence according to GRADE was low.

AUTHORS' CONCLUSIONS

The paucity and low quality of existing data do not provide sufficient evidence to establish the role of paracetamol in reducing the effects of painful procedures in neonates. Paracetamol given after assisted vaginal birth may increase the response to later painful exposures. Paracetamol may reduce the total need for morphine following major surgery, and for this aspect of paracetamol use, further research is needed.

Can intravenous acetaminophen reduce the needs to more opioids to control pain in intubated patients?

AIMS

To evaluate the effect of intravenous (IV) acetaminophen on reducing the need for morphine sulfate in intubated patients admitted to the Intensive Care Unit (ICU).

SETTINGS AND DESIGN

Current study was done as a clinical trial on the patients supported by mechanical ventilator.

SUBJECTS AND METHODS

Behavioral pain scale (BPS) scoring system was used to measure pain in the patients. All of the patients received 1 g, IV acetaminophen, every 6 h during the 1(st) and 3(rd) days of admission and placebo during the 2(nd) and 4(th) days. Total dose of morphine sulfate needed, its complications, and the BPS scores at the end of every 6 h interval were compared.

RESULTS

Totally forty patients were enrolled. The mean pain scores were significantly lower in the 2(nd) and 4(th) days (4.33 and 3.66, respectively; mean: 4.0) in which the patients had received just morphine sulfate compared to the 1(st) and 3(rd) days (7.36 and 3.93, respectively; mean: 5.65) in which the patients had received acetaminophen in addition to morphine sulfate too (P < 0.001). Cumulative dose of morphine sulfate used, was significantly higher in the 1(st) and 3(rd) days (8.92 and 3.15 mg, respectively; 12.07 mg in total) compared to the 2(nd) and 4(th) days (6.47 mg and 3.22 mg, respectively; 9.7 mg in total) (P = 0.035).

CONCLUSION

In our study, IV acetaminophen had no effect on decreasing the BPSs and need of morphine sulfate in intubated patients admitted to ICU.

Managing Pediatric Pain in the Emergency Department

Far more attention is now given to pain management in children in the emergency department (ED). When a child arrives, pain must be recognized and evaluated using a pain scale that is appropriate to the child's development and regularly assessed to determine whether the pain intervention was effective. At triage, both analgesics and non-pharmacological strategies, such as distraction, immobilization, and dressing should be started. For mild pain, oral ibuprofen can be administered if the child has not received it at home, whereas ibuprofen and paracetamol are suitable for moderate pain. For patients who still require pain relief, oral opioids could be considered; however, many EDs have now replaced this with intranasal fentanyl, which allows faster onset of pain relief and can be administered on arrival pending either intravenous access or definitive care. Intravenous opioids are often required for severe pain, and paracetamol or ibuprofen can still be considered for their likely opioid-sparing effects. Specific treatment should be used for patients with migraine. In children requiring intravenous access or venipuncture, non-pharmacological and pharmacological strategies to decrease pain and anxiety associated with needle punctures are mandatory. These strategies can also be used for laceration repairs and other painful procedures. Despite the gaps in knowledge, pain should be treated with the most up-to-date evidence in children seen in EDs.

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.

Evaluation of a protocol-based intervention to promote timely switching from intravenous to oral paracetamol for post-operative pain management: an interrupted time series analysis

RATIONALE, AIMS AND OBJECTIVES

Timely switching from intravenous to oral therapy ensures optimized treatment and efficient use of health care resources. Intravenous (IV) paracetamol is widely used for post-operative pain management but not always switched to the oral form in a timely manner, leading to unnecessary increase in expenditure. This study aims to evaluate the impact of a multifaceted intervention to promote timely switching from the IV to oral form in the post-operative setting.

METHODS

An evidence-based prescribing protocol was designed and implemented by the clinical pharmacy team in a single district general hospital in Egypt. The protocol specified the criteria for appropriate prescribing of IV paracetamol. Doctors were provided with information and educational sessions prior to implementation. A prospective, quasi-experimental study was undertaken to evaluate its impact on IV paracetamol utilization and costs. Data on monthly utilization and costs were recorded for 12 months before and after implementation (January 2012 to December 2013). Data were analysed using interrupted time series analysis.

RESULTS

Prior to implementation, in 2012, total spending on IV paracetamol was 674 154.00 Egyptian Pounds (L.E.) ($23,668.00). There was a non-significant (P > 0.05) downward trend in utilization (-32 ampoules per month) and costs [reduction of 632 L.E. ($222) per month]. Following implementation, immediate decrease in utilization and costs (P < 0.05) and a trend change over the follow-up period were observed. Average monthly reduction was 26% (95% CI: 24% to 28%, P < 0.001).

CONCLUSION

A multifaceted, protocol-based intervention to ensure timely switching from IV-to-oral paracetamol achieved significant reduction in utilization and cost of IV paracetamol in the first 5 months of its implementation.

[Prehospital analgesia by paramedics in Rhineland-Palatinate : Feasability, analgesic effectiveness and safety of intravenous paracetamol]

BACKGROUND

In contrast to the widespread practice in life-threatening emergencies, delegation of medical pain therapy to paramedics by the medical director  of Emergency Medical Services, EMS, are still the exception in Germany. This is due to the fact that in non-life-threatening situations, the expected benefit and potential side effects of drug therapy have to be carefully weighed. In addition, in Germany federal law generally restricts the administration of opiates to physicians.

METHODS

In 2011 the medical directors of EMS in the German state of Rhineland- Palatinate (4 million inhabitants) developed and implemented a standard operating procedure (SOP) for paramedics related to the prehospital parenteral administration of paracetamol for patients with isolated limb trauma. After a 2 h training session and examination, paramedics were authorized to administer 1 g of paracetamol to patients with a pain score > 5 points on an 11-point numerical rating scale (NRS). For purposes of quality management, every administration of paracetamol had to be prospectively documented on a specific electronic mission form.

RESULTS

A total of 416 mission forms could be analyzed. After administration of paracetamol the median NRS score decreased from 8 points (interquartile range: 6; 8) to 4 points (interquartile range: 3; 7). In 51.2 % of the patients the pain intensity was reduced by at least 3 NRS points and in 50.5 % of the patients the NRS was less than 5 points after treatment. The extent of pain reduction was positively correlated with the initial NRS value (r = 0.31, p < 0.0001). No serious side effects were noted. The percentage of patients with an initial heart rate > 100/min declined from 14.6 % to 5.2 % after the administration of paracetamol (p < 0.0001), 18.7 % of the patients received paracetamol for trauma not related to the extremities and 7 % of the patients for nontraumatic pain. An emergency physician was involved in 50 % of the EMS missions and 98.6 % of the patients were transported to a hospital for further diagnostics and treatment.

CONCLUSION

The prehospital intravenous administration of paracetamol by paramedics to patients with limb trauma is simple, safe and in 50 % of the patients effective in achieving a NRS value < 5; however, further improvements in prehospital pain therapy initiated by paramedics are desirable, especially in patients with an initial NRS value > 7.

Evaluation of a Single Dose Intravenous Paracetamol for Pain Relief After Maxillofacial Surgery: A Randomized Clinical Trial Study

OBJECTIVE

The aim of this study was to evaluate, using a single dose of intravenous paracetamol, pain relief after maxillofacial surgery.

MATERIALS AND METHODS

This is a controlled, randomized, uni- blind, clinical trial study to evaluate using a single dose of IV paracetamol for pain relief after maxillofacial surgery. The subjects were randomly divided into two groups with 40 subjects in each: group I received paracetamol (Apotel)* as a single dose and group II received placebo. Subjects were randomly allocated according to randomization lists. Paracetamol was used as a single dose (20 mg/kg in 100 cc of normal saline which was infused for 10 min after surgery in recovery room just before discharging). We used a visual analogue scale to investigate pain relief at various times.

RESULTS

Analysis of the data, did not show any significant difference for age, sex and weight between the treatment group and the control group. Pain decreased 6 h after paracetamol infusion; then it increased mildly. In the control group, pain severity increased after operation, then it decreased mildly. Results showed a correlation between duration of surgery and pain severity in both the groups.

CONCLUSION

Paracetamol is effective on pain relief after maxillofacial surgeries. Operation time may be an important factor for induction of pain after the surgeries.

Paracetamol (acetaminophen) for prevention or treatment of pain in newborns

BACKGROUND

Newborn infants have the ability to experience pain. Newborns treated in neonatal intensive care units are exposed to numerous painful procedures. Healthy newborns are exposed to pain if the birth process consists of assisted vaginal birth by vacuum extraction or by forceps and during blood sampling for newborn screening tests.

OBJECTIVES

Primary objectiveTo determine the efficacy and safety of paracetamol for the prevention or treatment of procedural/postoperative pain or pain associated with clinical conditions in neonates. Secondary objectiveTo review the effects of various doses and routes of administration (enteral, intravenous or rectal) of paracetamol for the prevention or treatment of pain in neonates. We designed the main comparisons according to intention of use, that is, paracetamol for prevention or treatment of pain. We included separate comparisons based on the painful intervention/procedure/condition (heel lance, insertion of nasogastric tube, insertion of intravenous catheter, lumbar puncture, assisted vaginal birth, postoperative pain, birth trauma, congenital anomalies such as myelomeningocoele and open cutaneous lesions) and the mode of administration of paracetamol. Within these comparisons, we planned to assess in subgroups (when possible) effects based on postmenstrual age (PMA) at the birth of randomly assigned infants (< 28 weeks, 28 weeks to 31 + 6 weeks, 32 weeks to 36 + 6 weeks and ≥ 37 weeks) or based on birth weight (or current weight) categories (≤ 1000 grams, 1001 to 1500 grams, 1501 to 2500 grams and ≥ 2501 grams)

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group including electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (October 2014), MEDLINE (1966 to October 2014), EMBASE (1980 to October 2014) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to October 2014). We applied no language restrictions.We conducted electronic searches of abstracts from meetings of the Pediatric Academic Societies (2000 to 2014) and the Perinatal Society of Australia and New Zealand (2010 to 2014).We searched clinical trial registries for ongoing trials and the Web of Science for articles quoting identified randomised controlled trials. We searched the first 200 hits on Google Scholar(TM) to identify grey literature.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials of paracetamol for the prevention or treatment of pain in neonates (≤ 30 days of age).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from the full-text articles using a specifically designed form. We used this form to decide trial inclusion/exclusion, to extract data from eligible trials and to request additional published information from authors of the original reports. We entered and cross-checked data using RevMan 5.3.3 software. When noted, we resolved differences by mutual discussion and consensus.

MAIN RESULTS

We included eight trials with low risk of bias, which assessed paracetamol use for the treatment of pain in 614 infants. Painful interventions studied included heel lance, assisted vaginal birth, eye examination for ascertainment of retinopathy of prematurity (ROP) and postoperative care following major surgery. Results of individual studies could not be combined in meta-analyses as the painful conditions, the use of paracetamol and comparison interventions and the outcome measures differed. Paracetamol compared with water, cherry elixir or EMLA cream did not significantly reduce pain following heel lance. The Premature Infant Pain Profile score (PIPP) within three minutes following lancing was higher in the paracetamol group than in the oral glucose group (mean difference (MD) 2.21, 95% confidence interval (CI) 0.72 to 3.70; one study, 38 infants). Paracetamol did not reduce "modified facies scores" after assisted vaginal birth (one study, 119 infants). In another study (n = 123), the Échelle de Douleur et d'Inconfort du Nouveau-Né score at two hours of age was significantly higher in the group that received paracetamol suppositories than in the placebo suppositories group (MD 1.00, 95% CI 0.60 to 1.40). In that study, when infants were subjected to a heel lance at two to three days of age, Bernese Pain Scale for Neonates scores were higher in the paracetamol group than in the placebo group, and infants spent a longer time crying (MD 19 seconds, 95% CI 14 to 24). For eye examinations, no significant reduction in PIPP scores in the first or last 45 seconds of eye examination was reported, nor at five minutes after the eye examination. In one study (n = 81), the PIPP score was significantly higher in the paracetamol group than in the 24% sucrose group (MD 3.90, 95% CI 2.92 to 4.88). For postoperative care following major thoracic or abdominal surgery, the total amount of morphine (µg/kg) administered over 48 hours was significantly less among infants randomly assigned to the paracetamol group than in those randomly assigned to the morphine group (MD -157 µg/kg, 95% CI -27 to -288). No adverse events were noted in any study.

AUTHORS' CONCLUSIONS

Paracetamol does not significantly reduce pain associated with heel lance or eye examinations. Paracetamol given after assisted vaginal birth may increase the response to later painful exposures. Paracetamol should not be used for painful procedures given its lack of efficacy and its potential for adverse effects. Paracetamol may reduce the total need for morphine following major surgery, and for this aspect of paracetamol use, further research is needed.

[Pediatric perioperative systemic pain therapy: Austrian interdisciplinary recommendations on pediatric perioperative pain management]

BACKGROUND

Many analgesics used in adult medicine are not licensed for pediatric use. Licensing limitations do not, however, justify that children are deprived of a sufficient pain therapy particularly in perioperative pain therapy. The treatment is principally oriented to the strength of the pain. Due to the degree of pain caused, intramuscular and subcutaneous injections should be avoided generally.

NON-OPIOIDS

The basis of systemic pain therapy for children are non-opioids and primarily non-steroidal anti-inflammatory drugs (NSAIDs). They should be used prophylactically. The NSAIDs are clearly more effective than paracetamol for acute posttraumatic and postoperative pain and additionally allow economization of opioids. Severe side effects are rare in children but administration should be carefully considered especially in cases of hepatic and renal dysfunction or coagulation disorders. Paracetamol should only be taken in pregnancy and by children when there are appropriate indications because a possible causal connection with bronchial asthma exists. To ensure a safe dosing the age, body weight, duration of therapy, maximum daily dose and dosing intervals must be taken into account. Dipyrone is used in children for treatment of visceral pain and cholic. According to the current state of knowledge the rare but severe side effect of agranulocytosis does not justify a general rejection for short-term perioperative administration.

OPIOIDS

In cases of insufficient analgesia with non-opioid analgesics, the complementary use of opioids is also appropriate for children of all age groups. They are the medication of choice for episodes of medium to strong pain and are administered in a titrated form oriented to effectiveness. If severe pain is expected to last for more than 24 h, patient-controlled anesthesia should be implemented but requires a comprehensive surveillance by nursing personnel.

KETAMINE

Ketamine is used as an adjuvant in postoperative pain therapy and is recommended for use in pediatric sedation and analgosedation.

Adverse effects of perioperative paracetamol, NSAIDs, glucocorticoids, gabapentinoids and their combinations: a topical review

Post-operative pain affects millions of patients worldwide and the post-operative period has high rates of morbidity and mortality. Some of this morbidity may be related to analgesics. The aim of this review was to provide an update of current knowledge of adverse events (AE) associated with the most common perioperative non-opioid analgesics: paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids (GCCs), gabapentinoids and their combinations. The review is based on data from systematic reviews with meta-analyses of analgesic efficacy and/or adverse effects of perioperative non-opioid analgesics, and randomised trials and cohort/retrospective studies. Generally, data on AE are sparse and related to the immediate post-operative period. For paracetamol, the incidence of AEs appears trivial. Data are inconclusive regarding an association of NSAIDs with mortality, cardiovascular events, surgical bleeding and renal impairment. Anastomotic leakage may be associated with NSAID usage. No firm evidence exists for an association of NSAIDs with impaired bone healing. Single-dose GCCs were not significantly related to increased infection rates or delayed wound healing. Gabapentinoid treatment was associated with increased sedation, dizziness and visual disturbances, but the clinical relevance needs clarification. Importantly, data on AEs of combinations of the above analgesics are sparse and inconclusive. Despite the potential adverse events associated with the most commonly applied non-opioid analgesics, including their combinations, reporting of such events is sparse and confined to the immediate perioperative period. Knowledge of benefit and harm related to multimodal pain treatment is deficient and needs clarification in large trials with prolonged observation.

Post-operative analgesic effects of paracetamol, NSAIDs, glucocorticoids, gabapentinoids and their combinations: a topical review

In contemporary post-operative pain management, patients are most often treated with combinations of non-opioid analgesics, to enhance pain relief and to reduce opioid requirements and opioid-related adverse effects. A diversity of combinations is currently employed in clinical practice, and no well-documented 'gold standards' exist. The aim of the present topical, narrative review is to provide an update of the evidence for post-operative analgesic efficacy with the most commonly used, systemic non-opioid drugs, paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs)/COX-2 antagonists, glucocorticoids, gabapentinoids, and combinations of these. The review is based on data from previous systematic reviews with meta-analyses, investigating effects of non-opioid analgesics on pain, opioid-requirements, and opioid-related adverse effects. Paracetamol, NSAIDs, COX-2 antagonists, and gabapentin reduced 24 h post-operative morphine requirements with 6.3 (95% confidence interval: 3.7 to 9.0) mg, 10.2 (8.7, 11.7) mg, 10.9 (9.1, 12.8) mg, and ≥ 13 mg, respectively, when administered as monotherapy. The opioid-sparing effect of glucocorticoids was less convincing, 2.33 (0.26, 4.39) mg morphine/24 h. Trials of pregabalin > 300 mg/day indicated a morphine-sparing effect of 13.4 (4, 22.8) mg morphine/24 h. Notably, though, the available evidence for additive or synergistic effects of most combination regimens was sparse or lacking. Paracetamol, NSAIDs, selective COX-2 antagonists, and gabapentin all seem to have well-documented, clinically relevant analgesic properties. The analgesic effects of glucocorticoids and pregabalin await further clarification. Combination regimens are sparsely documented and should be further investigated in future studies.

Intravenous paracetamol versus intramuscular pethidine in relief of labour pain in primigravid women

BACKGROUND

Intramuscular pethidine is one of most common opioids used for labour analgesia. There are a number of concerns in the literature regarding the use of pethidine. The aim of this study is to compare analgesic efficacy of paracetamol with pethidine for labour pain in normal vaginal delivery.

MATERIALS AND METHODS

In this single-blinded, randomised control trial, 80 primigravid singleton women with full-term pregnancy candidate for normal vaginal delivery, were entered the trial and divided in to pethidine (A) and paracetamol (B) groups. At the time of admission, age and body mass index of mother and gestational age based on last day of period were recorded. In both groups, intravenous promethazine and hyoscine were administered to each patient at the first stage of delivery. From beginning of active phase of delivery, patients in group A received 50 mg intramuscular pethidine injection. At the same time patients in group B, received an intravenous solution infusion containing 1000 mg paracetamol and 300 cc of normal saline. After child birth, average labour pain was assessed using Visual Analogue Scale (VAS) by direct questioning from patient in both groups.

RESULTS

After patients' selection, 19 individual omitted during study due to exclusion criteria and finally 30 patients in paracetamol group and 31 patients in pethidine group remained to enter the trial. There was no significant difference in age and BMI of mothers between both groups (P > 0.05). Maternal age and labour duration in paracetamol group had no meaningful difference with maternal age and labour duration of patients in pethidine group (P > 0.05). The average VAS pain score was significantly lower in paracetamol comparing to that of pethidine group (8.366 out of 10, 9.612 out of 10, respectively, P < 0.001).

CONCLUSION

It is concluded that intravenous paracetamol is more effective than intramuscular pethidine to relief labour pain in normal vaginal delivery.

Intravenous acetaminophen is superior to ketamine for postoperative pain after abdominal hysterectomy: results of a prospective, randomized, double-blind, multicenter clinical trial

BACKGROUND

In recent years, intravenously (IV) administered acetaminophen has become one of the most common perioperative analgesics. Despite its now-routine use, IV acetaminophen's analgesic comparative efficacy has never been compared with that of ketamine, a decades-old analgesic familiar to obstetricians, gynecologists, and anesthesiologists alike. This doubleblind clinical trial aimed to evaluate the analgesic effects of ketamine and IV acetaminophen on postoperative pain after abdominal hysterectomy.

METHODS

Eighty women aged 25-70 years old and meeting inclusion and exclusion criteria were randomly allocated into two groups of 40 to receive either IV acetaminophen or ketamine intraoperatively. Postoperatively, each patient had patient-controlled analgesia. Pain and sedation (Ramsay Sedation Scale) were documented based on the visual analog scale in the recovery room and at 4 hours, 6 hours, 12 hours, and 24 hours after the surgery. Hemodynamic changes, adverse medication effects, and the need for breakthrough meperidine were also recorded for both groups. Data were analyzed by repeated-measures analysis of variance.

RESULTS

Visual analog scale scores were significantly lower in the IV acetaminophen group at each time point (P<0.05), and this group required significantly fewer doses of breakthrough analgesics compared with the ketamine group (P=0.039). The two groups had no significant differences in terms of adverse effects.

CONCLUSION

Compared with ketamine, IV acetaminophen significantly improved postoperative pain after abdominal hysterectomy.

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.

Pre-operative assessment and post-operative care in elective shoulder surgery

Pre-operative assessment is required prior to the majority of elective surgical procedures, primarily to ensure that the patient is fit to undergo surgery, whilst identifying issues that may need to be dealt with by the surgical or anaesthetic teams. The post-operative management of elective surgical patients begins during the peri-operative period and involves several health professionals. Appropriate monitoring and repeated clinical assessments are required in order for the signs of surgical complications to be recognised swiftly and adequately. This article examines the literature regarding pre-operative assessment in elective orthopaedic surgery and shoulder surgery, whilst also reviewing the essentials of peri- and post-operative care. The need to recognise common post-operative complications early and promptly is also evaluated, along with discussing thromboprophylaxis and post-operative analgesia following shoulder surgery.

Clinical pharmacology of analgesics assessed with human experimental pain models: bridging basic and clinical research

The medical impact of pain is such that much effort is being applied to develop novel analgesic drugs directed towards new targets and to investigate the analgesic efficacy of known drugs. Ongoing research requires cost-saving tools to translate basic science knowledge into clinically effective analgesic compounds. In this review we have re-examined the prediction of clinical analgesia by human experimental pain models as a basis for model selection in phase I studies. The overall prediction of analgesic efficacy or failure of a drug correlated well between experimental and clinical settings. However, correct model selection requires more detailed information about which model predicts a particular clinical pain condition. We hypothesized that if an analgesic drug was effective in an experimental pain model and also a specific clinical pain condition, then that model might be predictive for that particular condition and should be selected for development as an analgesic for that condition. The validity of the prediction increases with an increase in the numbers of analgesic drug classes for which this agreement was shown. From available evidence, only five clinical pain conditions were correctly predicted by seven different pain models for at least three different drugs. Most of these models combine a sensitization method. The analysis also identified several models with low impact with respect to their clinical translation. Thus, the presently identified agreements and non-agreements between analgesic effects on experimental and on clinical pain may serve as a solid basis to identify complex sets of human pain models that bridge basic science with clinical pain research.

Clinical pharmacology of intravenous paracetamol in perinatal medicine

Clinical pharmacology aims to predict drug-related effects based on compound and population specific pharmacokinetics (PK, concentration-time), and pharmacodynamics (PD, concentration-effect). Consequently, dosing needs to be based on the physiological characteristics of the individual patient. Pregnancy and early infancy hereby warrant focused assessment. The specific characteristics of both subpopulations will be illustrated based on observations on intravenous (iv) paracetamol PK and PD collected in these specific populations. At delivery, there is a significant higher paracetamol clearance (+ 45%, L/h) when compared to non-pregnant observations. This higher clearance is in part explained by a proportional increase in oxidative metabolite production, but mainly an increase in glucuronidation. When focusing on PD, an association between maternal paracetamol exposure and atopy in infancy and fetal gastroshizis has been reported. In early infancy, paracetamol clearance is significantly lower and mainly depends on size (weight 0.75), while also the distribution volume is higher (L/kg). Reports on hepatic tolerance, haemodynamic stability and impact of body temperature have been published while the concentration effect profile for analgesia seems to be similar between neonates and children. Similar to maternal exposure, there are reports on the association with atopy. Studies on the use of paracetamol to close the patent ductus arteriosus are ongoing. At least, these observations provide evidence on the need to study commonly administered anesthetics in such specific subpopulations with specific focus on both population specific PK and PD to further improve patient tailored pharmacotherapy.