Single dose oral paracetamol (acetaminophen) for postoperative pain in adults

Structure-activity relationship of pharmacophores and toxicophores: the need for clinical strategy

OBJECTIVES

Sometimes clinical efficacy and potential risk of therapeutic and toxic agents are difficult to predict over a long period of time. Hence there is need for literature search with a view to assessing cause of toxicity and less efficacy of drugs used in clinical practice.

METHOD

Hence literatures were searched for physicochemical properties, chemical formulas, molecular masses, pH values, ionization, receptor type, agonist and antagonist, therapeutic, toxic and structure-activity relationship of chemical compounds with pharmacophore and toxicophore, with a view to identifying high efficacious and relative low toxic agents. Inclusion criteria were manuscripts published on PubMed, Scopus, Web of Science, PubMed Central, Google Scholar among others, between 1960 and 2023. Keywords such as pharmacophore, toxicophore, structure-activity-relationship and disease where also searched. The exclusion criteria were the chemicals that lack pharmacophore, toxicophore and manuscripts published before 1960.

RESULTS

Findings have shown that pharmacophore and toxicophore functional groups determine clinical efficacy and safety of therapeutics, but if they overlap therapeutic and toxicity effects go concurrently. Hence the functional groups, dose, co-administration and concentration of drugs at receptor, drug-receptor binding and duration of receptor binding are the determining factors of pharmacophore and toxicophore activity. Molecular mass, chemical configuration, pH value, receptor affinity and binding capacity, multiple pharmacophores, hydrophilic/lipophilic nature of the chemical contribute greatly to functionality of pharmacophore and toxicophore.

CONCLUSION

Daily single therapy, avoidance of reversible pharmacology, drugs with covalent adduct, maintenance of therapeutic dose, and the use of multiple pharmacophores for terminal diseases will minimize toxicity and improve efficacy.

Is Paracetamol Better than Diclofenac Sodium in Management of Postoperative Pain and Edema Following Major Maxillofacial Surgeries?

Introduction

Paracetamol is an optimal non-opioid analgesic and holds considerable advantages over NSAIDs in managing post-operative pain. Literature to date doesn't provide substantial documentation of it's efficacy and safety in major oral and maxillofacial surgeries. The study is designed to compare the effectiveness of intravenous paracetamol with diclofenac sodium for controlling post-operative pain and edema in major oral and maxillofacial surgeries.

Method

The double-blind randomised prospective study includes 140 healthy patients with ASA grades I and II. Patients were divided into Group A (1gm paracetamol) and B (75 mg diclofenac sodium), 70 patients each, undergoing similar surgical procedures. VAS and VRS were assessed for pain and thread method for measuring swelling. Mouth opening in space infections was measured with calliper and scale.

Results

Independent samples t-test and chi-square test showed longer pain-free interval, more interval between first and second dose, lesser number of doses required in Group A than Group B (p-value < 0.05). Independent samples t-test and Mann-Whitney test showed faster resolution of swelling in Group A (p-value < 0.05). Independent samples t-test showed lesser time taken for resolution of trismus in space infections in Group A (p-value < 0.05).

Discussion

Paracetamol 1 g was found to be an effective analgesic with less adverse effects. It is superior non-opioid analgesic in reducing the intensity of post-operative pain and swelling, also requires less number of doses than diclofenac sodium in major surgeries. Patients treated with paracetamol had better quality of life during post-operative period.

Integrating mechanistic-based and classification-based concepts into perioperative pain management: an educational guide for acute pain physicians

Chronic pain begins with acute pain. Physicians tend to classify pain by duration (acute vs chronic) and mechanism (nociceptive, neuropathic and nociplastic). Although this taxonomy may facilitate diagnosis and documentation, such categories are to some degree arbitrary constructs, with significant overlap in terms of mechanisms and treatments. In clinical practice, there are myriad different definitions for chronic pain and a substantial portion of chronic pain involves mixed phenotypes. Classification of pain based on acuity and mechanisms informs management at all levels and constitutes a critical part of guidelines and treatment for chronic pain care. Yet specialty care is often siloed, with advances in understanding lagging years behind in some areas in which these developments should be at the forefront of clinical practice. For example, in perioperative pain management, enhanced recovery protocols are not standardized and tend to drive treatment without consideration of mechanisms, which in many cases may be incongruent with personalized medicine and mechanism-based treatment. In this educational document, we discuss mechanisms and classification of pain as it pertains to commonly performed surgical procedures. Our goal is to provide a clinical reference for the acute pain physician to facilitate pain management decision-making (both diagnosis and therapy) in the perioperative period.

Comparison between the Effects of Acetaminophen, Dexmedetomidine, and Normal Saline Infusion on Pain Severity after Cataract Surgery

BACKGROUND

Cataract surgery is one of the most common eye surgeries, which is currently performed under topical anesthesia using sedative medications. Dexmedetomidine and acetaminophen are good candidates for analgesia in other circumstances, however, this study aimed to evaluate the effect of dexmedetomidine or acetaminophen infusion and normal saline (NS) alone compared with the control group on the severity of pain in cataract surgery.

MATERIALS AND METHODS

In this parallel randomized controlled clinical trial, the effect of dexmedetomidine or acetaminophen infusion and NS on level of pain, vital signs, recovery status, and surgeon satisfaction during cataract surgery were assessed. One hundred and thirty-five patients between the age of 50-80 years undergoing cataract surgery were recruited on a consecutive basis and randomized into three groups receiving acetaminophen (15 mg/kg), dexmedetomidine (0.5 μgr/kg), and NS. Baseline vital signs, blood pressure, arterial oxygen saturation, respiratory and heart rate at certain time-points including the start of surgery, 5, 10, and 15 min after surgery, after arrival to the recovery room, 20, 40, 60 min after recovery were measured. Pain intensity and drugs side effects were also recorded after surgery.

RESULTS

Level of respiratory depression was higher in patients receiving dexmedetomidine. Heart rate and oxygen saturation percentage had no significant differences in the three groups as well as pain intensity.

CONCLUSIONS

Acetaminophen was as effective as dexmedetomidine with lower side effects and higher surgeons' satisfaction, without any interference with cardiovascular and respiratory parameters. Acetaminophen infusion should be considered as an acceptable analgesic drug for cataract surgery.

Randomized double-blind controlled trial to assess the efficacy of intravenous acetaminophen associated with strong opioids in the treatment of acute pain in adult cancer patients: study protocol

Background

Cancer pain is one of the most frequent and relevant symptoms in cancer patients and impacts on patient’s quality of life. International and local standards recommend as an initial strategy the use of an analgesic scheme composed of strong opioids associated with adjuvants such as acetaminophen, based upon the assumption that combining drugs could have a better analgesic effect, could allow lowering opioid dosing, and could prevent the occurrence of adverse effects of opioids. However, there is uncertainty about the impact of acetaminophen as an adjuvant in patients who use strong opioids for moderate to severe pain management in cancer patients. The aim of this study is to assess the efficacy and safety of intravenous acetaminophen associated with strong opioids in hospitalized adult cancer patients who have moderate to severe cancer-related pain.

Methods

We will perform a randomized double-blinded controlled study comparing intravenous acetaminophen 1 g 4 times a day versus placebo for 48 h as an adjuvant to strong opioids. We will assess pain intensity as a primary outcome, using the verbal numerical rating scale (VNRS, I0 to 10 scale with higher scores meaning higher pain intensity), and we will compare the mean difference in pain intensity between baseline and 48 h among the placebo and intervention groups. We estimate that a decrease of 1 point in the VNRS would be clinically significant. Assuming a standard deviation in pain intensity of 1.7 points, an alpha of 0.025, and a power of 0.8, we estimate a sample size of 112 patients, with 56 patients in each arm. Secondary outcomes include the difference in total opioid use between baseline and at 48 h among the groups, and adverse effects such as drowsiness, constipation, nausea, and vomiting would be evaluated.

Discussion

The randomized, double-blind, placebo-controlled design is the best strategy to assess the efficacy of acetaminophen as an adjuvant in adult cancer patients with moderate to severe pain who are receiving strong opioids. We expect to contribute to national and international guidelines with these results.

Trial registration

Clinicaltrials.gov NCT04779567. Registered on March 3, 2021. Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06442-2.

Nonopioid analgesics for analgesia in critically ill patients: Friends, enemies, or collaborators

Patients in intensive care units (ICUs) experience pain, which they describe as a significant cause of stress during treatment. It can progress to chronic pain and significantly affect the quality of life. Opioids have long been the backbone of ICU pain therapy. The consequences of their long-term use are known today, such as prolonged ICU stay and mechanical ventilation, resulting in increased treatment costs. Additionally, abstinence syndrome is a consequence of abrupt opioid withdrawal. Also, there is a risk of tolerance and hyperalgesia after prolonged opioid use. Globally, opioid dependence after hospital opioid treatment is alarming, although there is still a lack of data on its incidence after ICU. Multimodal analgesia enables comfort to the patient, opioid-sparing, and avoidance of side effects of non-opioid analgesics. Nonsteroidal anti-inflammatory drugs (NSAIDs) are a broad group of drugs recommended with paracetamol to treat mild to moderate acute postoperative pain. Although often prescribed by intensivists, their use in treating painful conditions in ICU is controversial due to the possible consequences on the organs of critically ill patients. Due to the inhibition of cyclooxygenases, NSAIDs indirectly cause vasoconstriction of the renal arteries and arterioles, leading to kidney damage. NSAIDs inhibit platelet aggregation and may predispose to bleeding. Analgesia of a critically ill patient is a important part of their treatment, however it can be challenging in certain patients. Numerous combinations of pharmacological and non-pharmacological approaches can be adapted to the patient's current characteristics.

Postoperative Pain Management in Enhanced Recovery Pathways

Postoperative pain is a common but often inadequately treated condition. Enhanced recovery pathways (ERPs) are increasingly being utilized to standardize perioperative care and improve outcomes. ERPs employ multimodal postoperative pain management strategies that minimize opioid use and promote recovery. While traditional opioid medications continue to play an important role in the treatment of postoperative pain, ERPs also rely on a wide range of non-opioid pharmacologic therapies as well as regional anesthesia techniques to manage pain in the postoperative setting. The evidence for the use of these interventions continues to evolve rapidly given the increasing focus on enhanced postoperative recovery. This article reviews the current evidence and knowledge gaps pertaining to commonly utilized modalities for postoperative pain management in ERPs.

Opioid Sparing Anesthesia and Enhanced Recovery After Surgery Protocol for Pancreaticoduodenectomy

Background

Opioid sparing anesthesia and enhanced recovery after surgery protocols are not innovative ideas. However, the utilization of pancreaticoduodenectomy is limited. With the rise in awareness of the opioid epidemic in the United States, we have created a multimodal approach to anesthesia and postoperative care to limit adverse effects of opioids and curb the use of opioids postoperatively.

Methods

We conducted a retrospective cohort study performed by chart review of an opioid-sparing anesthetic and enhanced recovery after surgery (ERAS) protocol initiated jointly by the anesthesiology departments and transplant surgery for pancreaticoduodenectomy from January 2017 to October 2019.

Results

Demographic data was found to be comparable between the control and protocol groups. Hospital length of stay, ICU length of stay, and opioid requirements significantly decreased in the protocol group. Hospital length of stay decreased from 8.92 to 5.72 days, ICU days decreased from 1.52 to 0.42 days, and narcotics for the first five hospital days were significantly decreased from 130.13 to 71.2 morphine milligram equivalents.

Conclusion

Proper postoperative pain management can improve patient satisfaction and decrease complication rates. Pancreaticoduodenectomy is a complicated procedure with relatively limited data regarding enhanced recovery after surgery protocols. Likewise, there is limited data regarding opioid-sparing anesthesia techniques. Our protocol produced promising hospital length of stay and reduced opioid administration during the first five hospital days without increasing 30-day readmission rates.

Enhanced recovery after surgery: anesthesia-related components

Background: Enhanced recovery after surgery (ERAS) is a multidisciplinary and multimodal evidence-based approach aimed at improving the recovery of surgical patients. Successful implementation of ERAS protocols requires proper perioperative communication and collaboration among surgeons, anesthesiologists, nurses, and other medical personnel.Current Concepts: The anesthesiologist is the clinical leader responsible for the ERAS program. Preoperative patient evaluation, optimization, and patient education are essential components of the ERAS program. The program also involves preoperative fasting and carbohydrate loading to minimize catabolic effects. Selection of an appropriate anesthetic regimen, fluid and temperature management, avoidance of intra/postoperative nausea and vomiting, and multimodal pain management are the key components of ERAS for which the anesthesiologist is responsible.Discussion and Conclusion: Factors that enable the successful implementation of ERAS include the willingness to change to ERAS, formation of multidisciplinary teams to improve cooperation, and support from the hospital management, as well as standardization of order sets and care processes and the appropriate use of audits. As the leader of the ERAS team, the anesthesiologist should be actively involved in comprehensive management of the patient during the perioperative period.

Single-dose intravenous ibuprofen for acute postoperative pain in adults

BACKGROUND

Postoperative administration of non-steroidal anti-inflammatory drugs (NSAIDs) reduces patient opioid requirements and, in turn, may reduce the incidence and severity of opioid-induced adverse events (AEs).

OBJECTIVES

To assess the analgesic efficacy and adverse effects of single-dose intravenous (IV) ibuprofen, compared with placebo or an active comparator, for moderate-to-severe postoperative pain in adults.

SEARCH METHODS

We searched the following databases without language restrictions: CENTRAL, MEDLINE, Embase and LILACS on 10 June 2021. We checked clinical trials registers and reference lists of retrieved articles for additional studies.

SELECTION CRITERIA

We included randomized trials that compared a single postoperative dose of intravenous (IV) ibuprofen with placebo or another active treatment, for treating acute postoperative pain in adults following any surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently considered trials for review inclusion, assessed risk of bias, and extracted data. Our primary outcome was the number of participants in each arm achieving at least 50% pain relief over a 4- and 6-hour period. Our secondary outcomes were time to, and number of participants using rescue medication; withdrawals due to lack of efficacy, adverse events (AEs), and for any other cause; and number of participants reporting or experiencing any AE, serious AEs (SAEs), and specific NSAID-related or opioid-related AEs. We were not able to carry out any planned meta-analysis. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

Only one study met our inclusion criteria, involving 201 total participants, mostly female (mean age 42 years), undergoing primary, unilateral, distal, first metatarsal bunionectomy (with osteotomy and internal fixation). Ibuprofen 300 mg, placebo or acetaminophen 1000 mg was administered intravenously to participants reporting moderate pain intensity the day after surgery. Since we identified only one study for inclusion, we did not perform any quantitative analyses. The study was at low risk of bias for most domains. We downgraded the certainty of the evidence due to serious study limitations, indirectness and imprecision. Ibuprofen versus placebo Findings of the single study found that at both the 4-hour and 6-hour assessment period, the proportion of participants with at least 50% pain relief was 32% (24/76) for those assigned to ibuprofen and 22% (11/50) for those assigned to placebo. These findings produced a risk ratio (RR) of 1.44 (95% confidence interval (CI) 0.77 to 2.66 versus placebo for at least 50% of maximum pain relief over the 4-hour and 6-hour period (very low-certainty evidence). Median time to rescue medication was 101 minutes for ibuprofen and 71 minutes for placebo (1 study, 126 participants; very low-certainty evidence). The number of participants using rescue medication was not reported within the included study. During the study (1 study, 126 participants), 58/76 (76%) of participants assigned to ibuprofen and 39/50 (78%) assigned to placebo reported or experienced any adverse event (AE), (RR 0.98, 95% CI 0.81 to 1.19; low-certainty evidence). No serious AEs (SAEs) were experienced (1 study, 126 participants; very low-certainty evidence). Ibuprofen versus active comparators Ibuprofen (300 mg) was similar to the active comparator, IV acetaminophen (1000 mg) at 4 hours and 6 hours (1 study, 126 participants). For those assigned to active control (acetaminophen), the proportion of participants with at least 50% pain relief was 35% (26/75) at 4 hours and 31% (23/75) at 6 hours. At 4 hours, these findings produced a RR of 0.91 (95% CI 0.58 to 1.43; very low-certainty evidence) versus active comparator (acetaminophen). At 6 hours, these findings produced a RR of 1.03 (95% CI 0.64 to 1.66; very low-certainty evidence) versus active comparator (acetaminophen). Median time to rescue medication was 101 minutes for ibuprofen and 125 minutes for the active comparator, acetaminophen (1 study, 151 participants; very low-certainty evidence). The number of participants using rescue medication was not reported within the included study. During the study, 8/76 (76%) of participants assigned to ibuprofen and 45/75 (60%) assigned to active control (acetaminophen) reported or experienced any AE, (RR 1.27, 95% CI 1.02 to 1.59; very low-certainty evidence). No SAEs were experienced (1 study, 151 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

There is insufficient evidence to support or refute the suggestion that IV ibuprofen is effective and safe for acute postoperative pain in adults.

Electrochemical determination of acetaminophen at a carbon electrode modified in the presence of β-cyclodextrin: role of the activated glassy carbon and the electropolymerised β-cyclodextrin

Acetaminophen is a well-known drug commonly used to provide pain relief, but it can also lead to acute liver failure at high concentrations. Therefore, there is considerable interest in monitoring its concentrations. Sensitive and selective acetaminophen electrochemical sensors were designed by cycling a glassy carbon electrode (GCE) to high potentials in the presence of β-CD in a phosphate electrolyte, or by simply activating the GCE electrode in the phosphate solution. Using cyclic voltammetry, adsorption-like voltammograms were recorded. The acetaminophen oxidation product, N-acetyl benzoquinone imine, was protected from hydrolysis, and this was attributed to the adsorption of acetaminophen at the modified GCE. The rate constants for the oxidation of acetaminophen were estimated as 4.3 × 10–3 cm2 s–1 and 3.4 × 10–3 cm2 s–1 for the β-CD-modified and -activated electrodes, respectively. Using differential pulse voltammetry, the limit of detection was calculated as 9.7 × 10–8 M with a linear concentration range extending from 0.1 to 80 μM. Furthermore, good selectivity was achieved in the presence of caffeine, ascorbic acid and aspirin, enabling the determination of acetaminophen in a commercial tablet. Similar electrochemical data were obtained for both the β-CD-modified and activated GCE surfaces, suggesting that the enhanced detection of acetaminophen is connected mainly to the activation and oxidation of the GCE. Using SEM, EDX and FTIR, no evidence was obtained to indicate that the β-CD was electropolymerised at the GCE.

Pain management after complex spine surgery: A systematic review and procedure-specific postoperative pain management recommendations

BACKGROUND

Complex spinal procedures are associated with intense pain in the postoperative period. Adequate peri-operative pain management has been shown to correlate with improved outcomes including early ambulation and early discharge.

OBJECTIVES

We aimed to evaluate the available literature and develop recommendations for optimal pain management after complex spine surgery.

DESIGN AND DATA SOURCES

A systematic review using the PROcedure SPECific postoperative pain managemenT methodology was undertaken. Randomised controlled trials and systematic reviews published in the English language from January 2008 to April 2020 assessing postoperative pain after complex spine surgery using analgesic, anaesthetic or surgical interventions were identified from MEDLINE, EMBASE and Cochrane Databases.

RESULTS

Out of 111 eligible studies identified, 31 randomised controlled trials and four systematic reviews met the inclusion criteria. Pre-operative and intra-operative interventions that improved postoperative pain were paracetamol, cyclo-oxygenase (COX)-2 specific-inhibitors or non-steroidal anti-inflammatory drugs (NSAIDs), intravenous ketamine infusion and regional analgesia techniques including epidural analgesia using local anaesthetics with or without opioids. Limited evidence was found for local wound infiltration, intrathecal and epidural opioids, erector spinae plane block, thoracolumbar interfascial plane block, intravenous lidocaine, dexmedetomidine and gabapentin.

CONCLUSIONS

The analgesic regimen for complex spine surgery should include pre-operative or intra-operative paracetamol and COX-2 specific inhibitors or NSAIDs, continued postoperatively with opioids used as rescue analgesics. Other recommendations are intra-operative ketamine and epidural analgesia using local anaesthetics with or without opioids. Although there is procedure-specific evidence in favour of intra-operative methadone, it is not recommended as it was compared with shorter-acting opioids and due to its limited safety profile. Furthermore, the methadone studies did not use non-opioid analgesics, which should be the primary analgesics to ultimately reduce overall opioid requirements, including methadone. Further qualitative randomised controlled trials are required to confirm the efficacy and safety of these recommended analgesics on postoperative pain relief.

Single-dose intravenous ketorolac for acute postoperative pain in adults

BACKGROUND

Postoperative pain is common and may be severe. Postoperative administration of non-steroidal anti-inflammatory drugs (NSAIDs) reduces patient opioid requirements and, in turn, may reduce the incidence and severity of opioid-induced adverse events (AEs).

OBJECTIVES

To assess the analgesic efficacy and adverse effects of single-dose intravenous ketorolac, compared with placebo or an active comparator, for moderate to severe postoperative pain in adults.

SEARCH METHODS

We searched the following databases without language restrictions: CENTRAL, MEDLINE, Embase and LILACS on 20 April 2020. We checked clinical trials registers and reference lists of retrieved articles for additional studies.

SELECTION CRITERIA

Randomized double-blind trials that compared a single postoperative dose of intravenous ketorolac with placebo or another active treatment, for treating acute postoperative pain in adults following any surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.  Our primary outcome was the number of participants in each arm achieving at least 50% pain relief over a four- and six-hour period. Our secondary outcomes were time to and number of participants using rescue medication; withdrawals due to lack of efficacy, adverse events (AEs), and for any other cause; and number of participants experiencing any AE, serious AEs (SAEs), and NSAID-related or opioid-related AEs. For subgroup analysis, we planned to analyze different doses of parenteral ketorolac separately and to analyze results based on the type of surgery performed. We assessed the certainty of evidence using GRADE.

MAIN RESULTS

We included 12 studies, involving 1905 participants undergoing various surgeries (pelvic/abdominal, dental, and orthopedic), with 17 to 83 participants receiving intravenous ketorolac in each study. Mean study population ages ranged from 22.5 years to 67.4 years. Most studies administered a dose of ketorolac of 30 mg; one study assessed 15 mg, and another administered 60 mg. Most studies had an unclear risk of bias for some domains, particularly allocation concealment and blinding, and a high risk of bias due to small sample size. The overall certainty of evidence for each outcome ranged from very low to moderate. Reasons for downgrading certainty included serious study limitations, inconsistency and imprecision. Ketorolac versus placebo Very low-certainty evidence from eight studies (658 participants) suggests that ketorolac results in a large increase in the number of participants achieving at least 50% pain relief over four hours compared to placebo, but the evidence is very uncertain (risk ratio (RR) 2.81, 95% confidence interval (CI) 1.80 to 4.37). The number needed to treat for one additional participant to benefit (NNTB) was 2.4 (95% CI 1.8 to 3.7). Low-certainty evidence from 10 studies (914 participants) demonstrates that ketorolac may result in a large increase in the number of participants achieving at least 50% pain relief over six hours compared to placebo (RR 3.26, 95% CI 1.93 to 5.51). The NNTB was 2.5 (95% CI 1.9 to 3.7). Among secondary outcomes, for time to rescue medication, moderate-certainty evidence comparing intravenous ketorolac versus placebo demonstrated a mean median of 271 minutes for ketorolac versus 104 minutes for placebo (6 studies, 633 participants). For the number of participants using rescue medication, very low-certainty evidence from five studies (417 participants) compared ketorolac with placebo. The RR was 0.60 (95% CI 0.36 to 1.00), that is, it did not demonstrate a difference between groups. Ketorolac probably results in a slight increase in total adverse event rates compared with placebo (74% versus 65%; 8 studies, 810 participants; RR 1.09, 95% CI 1.00 to 1.19; number needed to treat for an additional harmful event (NNTH) 16.7, 95% CI 8.3 to infinite, moderate-certainty evidence). Serious AEs were rare. Low-certainty evidence from eight studies (703 participants) did not demonstrate a difference in rates between ketorolac and placebo (RR 0.62, 95% CI 0.13 to 3.03). Ketorolac versus NSAIDs  Ketorolac was compared to parecoxib in four studies and diclofenac in two studies. For our primary outcome, over both four and six hours there was no evidence of a difference between intravenous ketorolac and another NSAID (low-certainty and moderate-certainty evidence, respectively). Over four hours, four studies (337 participants) produced an RR of 1.04 (95% CI 0.89 to 1.21) and over six hours, six studies (603 participants) produced an RR of 1.06 (95% CI 0.95 to 1.19). For time to rescue medication, low-certainty evidence from four studies (427 participants) suggested that participants receiving ketorolac waited an extra 35 minutes (mean median 331 minutes versus 296 minutes). For the number of participants using rescue medication, very low-certainty evidence from three studies (260 participants) compared ketorolac with another NSAID. The RR was 0.90 (95% CI 0.58 to 1.40), that is, there may be little or no difference between groups.   Ketorolac probably results in a slight increase in total adverse event rates compared with another NSAID (76% versus 68%, 5 studies, 516 participants; RR 1.11, 95% CI 1.00 to 1.23; NNTH 12.5, 95% CI 6.7 to infinite, moderate-certainty evidence). Serious AEs were rare. Low-certainty evidence from five studies (530 participants) did not demonstrate a difference in rates between ketorolac and another NSAID (RR 3.18, 95% CI 0.13 to 76.99). Only one of the five studies reported a single serious AE.

AUTHORS' CONCLUSIONS

The amount and certainty of evidence for the use of intravenous ketorolac as a treatment for postoperative pain varies across efficacy and safety outcomes and amongst comparators, from very low to moderate. The available evidence indicates that postoperative intravenous ketorolac administration may offer substantial pain relief for most patients, but further research may impact this estimate. Adverse events appear to occur at a slightly higher rate in comparison to placebo and to other NSAIDs. Insufficient information is available to assess whether intravenous ketorolac has a different rate of gastrointestinal or surgical-site bleeding, renal dysfunction, or cardiovascular events versus other NSAIDs. There was a lack of studies in cardiovascular surgeries and in elderly populations who may be at increased risk for adverse events.

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.

Efficacy of Anti-inflammatory Treatment Versus Rescue Analgesia After Arthroscopic Partial Meniscectomy in Nonarthritic Knees: A 3-Arm Controlled Study

Background

There is currently no consensus regarding the appropriate treatment for postoperative pain after arthroscopic partial meniscectomy (APM). Prescribing a mild non-anti-inflammatory protocol of rescue analgesia may be sufficient to avoid the side effects of opioids or anti-inflammatories.

Purpose/Hypothesis

The purpose was to compare the efficacy of pain reduction after APM in nonarthritic knees using betamethasone or celecoxib as anti-inflammatory analgesics versus acetaminophen or tramadol as rescue analgesics. The hypothesis was that there is no advantage for anti-inflammatories in achieving postoperative immediate pain relief after APM in nonarthritic knees compared with a simple nonopioid treatment.

Study Design

Cohort study; Level of evidence, 2.

Methods

This 3-arm controlled study evaluated postoperative pain levels and analgesic consumption in patients who underwent primary APM (under general anesthesia) at a single institution from December 2018 to December 2019. Patients were prospectively divided into 3 treatment groups: (1) betamethasone injection at the end of the procedure, (2) oral celecoxib prescription, or (3) neither treatment (control). All groups were instructed to take supplementary acetaminophen as needed. Patients were also allowed to take tramadol as needed to evaluate the need for opioids. At postoperative weeks 1, 2, and 3, patients completed the Knee injury and Osteoarthritis Outcome Score (KOOS) Pain subscale, and results were compared between time points and groups.

Results

A total of 99 patients were included in the treatment groups: betamethasone group (32 patients), celecoxib group (30 patients), and control group (37 patients). At baseline, there were no statistically significant differences between the groups in age, sex, body mass index, level of activity, comorbidities, or surgical findings. KOOS Pain scores improved at every time point for all 3 groups (P < .001), and no differences in scores were observed among groups. The consumption of acetaminophen or tramadol as rescue analgesia throughout the follow-up period was negligible among groups.

Conclusion

During the first 3 postoperative weeks after APM in nonarthritic knees, pain was efficiently controlled by betamethasone or celecoxib; however, pain was also efficiently controlled by minimal consumption of acetaminophen with negligible use of tramadol. Therefore, acetaminophen could be prescribed as an effective first-line postoperative analgesic after APM.

Preventive Analgesia, Hemodynamic Stability, and Pain in Vitreoretinal Surgery

Background and Objectives: Although vitreoretinal surgery (VRS) is most commonly performed under regional anaesthesia (RA), in patients who might be unable to cooperate during prolonged procedures, general anaesthesia (GA) with intraprocedural use of opioid analgesics (OA) might be worth considering. It seems that the surgical pleth index (SPI) can be used to optimise the intraprocedural titration of OA, which improves haemodynamic stability. Preventive analgesia (PA) is combined with GA to minimise intraprocedural OA administration. Materials and Methods: We evaluated the benefit of PA combined with GA using SPI-guided fentanyl (FNT) administration on the incidences of PIPP (postprocedural intolerable pain perception) and haemodynamic instability in patients undergoing VRS (p < 0.05). We randomly assigned 176 patients undergoing VRS to receive GA with SPI-guided FNT administration alone (GA group) or with preventive topical 2% proparacaine (topical anaesthesia (TA) group), a preprocedural peribulbar block (PBB) using 0.5% bupivacaine with 2% lidocaine (PBB group), or a preprocedural intravenous infusion of 1.0 g of metamizole (M group) or 1.0 g of paracetamol (P group). Results: Preventive PBB reduced the intraprocedural FNT requirement without influencing periprocedural outcomes (p < 0.05). Intraprocedural SPI-guided FNT administration during GA resulted in PIPP in 13.5% of patients undergoing VRS and blunted the periprocedural effects of preventive intravenous and regional analgesia with respect to PIPP and haemodynamic instability. Conclusions: SPI-guided FNT administration during GA eliminated the benefits of preventive analgesia in the PBB, TA, M, and P groups following VRS.

Paracetamol/acetaminophen (single administration) for perineal pain in the early postpartum period

BACKGROUND

Perineal pain is a common but poorly studied adverse outcome following childbirth. Pain may result from perineal trauma due to bruising, spontaneous tears, surgical incisions (episiotomies), or in association with operative vaginal births (ventouse or forceps-assisted births). This is an update of a review last published in 2013.

OBJECTIVES

To determine the efficacy of a single administration of paracetamol (acetaminophen) used in the relief of acute postpartum perineal pain.

SEARCH METHODS

For this update, we searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (9 December 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs), including cluster-RCTs, comparing paracetamol to placebo. We excluded quasi-RCTs and cross-over trials. Data from abstracts would be included only if authors had confirmed in writing that the data to be included in the review had come from the final analysis and would not change.

DATA COLLECTION AND ANALYSIS

Two review authors assessed each study for inclusion and extracted data. One review author reviewed the decisions and confirmed calculations for pain relief scores. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

This update identified no new trials so the results remain unchanged. However, by applying the GRADE assessment of the evidence, the interpretation of main results differed from previous version of this review. We identified 10 studies involving 2044 women, but all these studies involved either three or four groups, looking at differing drugs or doses. We have only included the 1301 women who were in the paracetamol versus placebo arms of the studies. Of these, five studies (482 women) assessed 500 mg to 650 mg and six studies (797 women) assessed 1000 mg of paracetamol. One study assessed 650 mg and 1000 mg compared with placebo and contributed to both comparisons. We used a random-effects meta-analysis because of the clinical variability among studies. Studies were from the 1970s to the early 1990s, and there was insufficient information to assess the risk of bias adequately, hence the findings need to be interpreted within this context. The certainty of the evidence for the two primary outcomes on which data were available was assessed as low, downgraded for overall unclear risk of bias and for heterogeneity (I² statistic 60% or greater). More women may experience pain relief with paracetamol compared with placebo (average risk ratio (RR) 2.14, 95% confidence interval (CI) 1.59 to 2.89; 10 trials, 1279 women), and fewer women may need additional pain relief with paracetamol compared with placebo (average RR 0.34, 95% CI 0.21 to 0.55; 8 trials, 1132 women). However, the certainty of the evidence was low, downgraded for unclear overall risk of bias and substantial heterogeneity. One study used the higher dose of paracetamol (1000 mg) and reported maternal drug adverse effects. There may be little or no difference in the incidence of nausea (average RR 0.18, 95% CI 0.01 to 3.66; 1 trial, 232 women; low-certainty evidence), or sleepiness (average RR 0.89, 95% CI 0.18 to 4.30; 1 trial, 232 women; low-certainty evidence). No other maternal adverse events were reported. None of the studies assessed neonatal drug adverse effects.

AUTHORS' CONCLUSIONS

A single dose of paracetamol may improve perineal pain relief following vaginal birth, and may reduce the need for additional pain relief. Potential adverse effects for both women and neonates were not appropriately assessed. Any further trials should also address the gaps in evidence concerning maternal outcomes such as satisfaction with postnatal care, maternal functioning/well-being (emotional attachment, self-efficacy, competence, autonomy, confidence, self-care, coping skills) and neonatal drug adverse effects.

[Considerations concerning the perioperative use of metamizole]

BACKGROUND

The non-opioid analgesic metamizole (dipyrone) is approved for the treatment of severe pain and is often used in the perioperative period. As it can cause agranulocytosis, a severe adverse event, its perioperative administration is controversially discussed.

OBJECTIVE

Is there enough evidence for a high risk of metamizol-induced agranulocytosis (MIA)? What are the consequences of its perioperative use with respect to the risk profiles of alternative analgesics?

MATERIAL AND METHODS

Rapid review of the literature on the risk of MIA and adverse effects of non-opioid analgesics.

RESULTS

The incidence of MIA is estimated to be one case per million inhabitants per year. The risk seems low compared to other drugs associated with a risk of agranulocytosis, such as antithyroid drugs and ticlopidine. The risk profile of metamizole concerning hepatotoxicity, nephrotoxicity, bleeding and cardiovascular adverse effects is favorable compared to other non-opioid analgesics. None of the non-opioid analgesics are licensed to be administered intraoperatively.

CONCLUSION

The perioperative use of metamizole is possible after a thorough evaluation of the indications as it provides good analgesia with a generally favorable side effect profile and is administered intravenously. The risk of agranulocytosis is small but needs to be mentioned during patient informed consent in order to optimize early recognition. Intraoperative administration aims at reducing the expected severe postoperative pain. A documentation and justification for the evaluation of the indications are recommended.

Association of Perioperative Opioid-Sparing Multimodal Analgesia With Narcotic Use and Pain Control After Head and Neck Free Flap Reconstruction

Importance

An increase in narcotic prescription patterns has contributed to the current opioid epidemic in the United States. Opioid-sparing perioperative analgesia represents a means of mitigating the risk of opioid dependence while providing superior perioperative analgesia.

Objective

To assess whether multimodal analgesia (MMA) is associated with reduced narcotic use and improved pain control compared with traditional narcotic-based analgesics at discharge and in the immediate postoperative period after free flap reconstructive surgery.

Design, Setting, and Participants

This retrospective cohort study assessed a consecutive sample of 65 patients (28 MMA, 37 controls) undergoing free flap reconstruction of a through-and-through mucosal defect within the head and neck region at a tertiary academic referral center from June 1, 2017, to November 30, 2018. Patients and physicians were not blinded to the patients' analgesic regimen. Patients' clinical courses were followed up for 30 days postoperatively.

Interventions

Patients were administered a preoperative, intraoperative, and postoperative analgesia regimen consisting of scheduled and as-needed neuromodulating and anti-inflammatory medications, with narcotic medications reserved for refractory cases. Control patients were administered traditional narcotic-based analgesics as needed.

Main Outcomes and Measures

Narcotic doses administered during the perioperative period and at discharge were converted to morphine-equivalent doses (MEDs) for comparison. Postoperative Defense and Veterans Pain Rating Scale pain scores (ranging from 0 [no pain] to 10 [worst pain imaginable]) were collected for the first 72 hours postoperatively as a patient-reported means of analyzing effectiveness of analgesia.

Results

A total of 28 patients (mean [SD] age, 64.1 [12.3] years; 17 [61%] male) were included in the MMA group and 37 (mean [SD] age, 65.0 [11.0] years; 22 [59%] male) in the control group. The number of MEDs administered postoperatively was 10.0 (interquartile range [IQR], 2.7-23.1) in the MMA cohort and 89.6 (IQR, 60.0-104.5) in the control cohort (P < .001). Mean (SD) Defense and Veterans Pain Rating Scale pain scores postoperatively were 2.05 (1.41) in the MMA cohort and 3.66 (1.99) in the control cohort (P = .001). Median number of MEDs prescribed at discharge were 0 (IQR, 0-18.8) in the MMA cohort and 300.0 (IQR, 262.5-412.5) in the control cohort (P < .001).

Conclusions and Relevance

The findings suggest that after free flap reconstruction, MMA is associated with reduced narcotic use at discharge and in the immediate postoperative period and with superior analgesia as measured by patient-reported pain scores. Patients receiving MMA achieved improved pain control, and the number of narcotic prescriptions in circulation were reduced.

Level of Evidence

3.

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.

Perioperative Epidural Use and Risk of Delirium in Surgical Patients: A Secondary Analysis of the PODCAST Trial

BACKGROUND

Postoperative delirium is an important public health concern without effective prevention strategies. This study tested the hypothesis that perioperative epidural use would be associated with decreased risk of delirium through postoperative day 3.

METHODS

This was a secondary, observational, nonrandomized analysis of data from The Prevention of Delirium and Complications Associated With Surgical Treatments Trial (PODCAST; NCT01690988). The primary outcome of the current study was the incidence of delirium (ie, any positive delirium screen, postanesthesia care unit through postoperative day 3) in surgical patients (gastrointestinal, hepatobiliary-pancreatic, gynecologic, and urologic) receiving postoperative epidural analgesia compared to those without an epidural. As a secondary outcome, all delirium assessments were then longitudinally analyzed in relation to epidural use throughout the follow-up period. Given the potential relevance to delirium, postoperative pain, opioid consumption, sleep disturbances, and symptoms of depression were also analyzed as secondary outcomes. A semiparsimonious multivariable logistic regression model was used to test the association between postoperative epidural use and delirium incidence, and generalized estimating equations were used to test associations with secondary outcomes described. Models included relevant covariates to adjust for confounding.

RESULTS

In total, 263 patients were included for analysis. Epidural use was not independently associated with reduced delirium incidence (adjusted odds ratio, 0.65 [95% CI, 0.32-1.35]; P = .247). However, when analyzing all assessments over the follow-up period, epidural patients were 64% less likely to experience an episode of delirium (adjusted odds ratio, 0.36 [95% CI, 0.17-0.78]; P = .009). Adjusted pain scores (visual analog scale, 0-100 mm) were significantly lower in the epidural group on postoperative day 1 (morning, -16 [95% CI, -26 to -7], P < .001; afternoon, -15 [95% CI, -25 to -5], P < .01) and postoperative day 3 (morning, -13 [95% CI, -20 to -5], P < .01). Adjusted mean oral and IV morphine equivalents were also significantly lower on postoperative day 1 in the epidural group (74% lower [95% CI, 55%-85%]; P < .0001). Finally, postoperative epidural use was not significantly associated with new sleep disturbances or changes in depression symptoms.

CONCLUSIONS

Postoperative epidural use was not associated with a reduced overall incidence of delirium. However, longitudinal analysis revealed reduced adjusted odds of experiencing an episode of delirium in the epidural group. Epidural use was also associated with reduced postoperative pain and opioid consumption. An appropriately designed follow-up study is warranted to further analyze the relationship among epidural use, postoperative delirium, and related outcomes.

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.

A Meta-Analysis of the Utility of Preoperative Intravenous Paracetamol for Post-Caesarean Analgesia

Background and objectives: Worldwide, the number of caesarean sections performed has increased exponentially. Some studies have reported better pain control and lower postoperative requirements for opioids when intravenous (IV) paracetamol was administered preoperatively. This meta-analysis thus aimed to investigate the utility of preoperative IV paracetamol for post-caesarean analgesia. Materials and Methods: By using the keywords (paracetamol OR acetaminophen) AND [cesarea* OR caesarea* OR cesaria* OR caesaria*], a systematic literature search was conducted using PubMed, Medline, Embase, Google Scholar and ClinicalTrials.gov databases for papers published in English between January 1, 1960 and March 1, 2019. Grey literature was searched as well. Results: Seven clinical trials were reviewed, while five randomized, placebo-controlled, double-blind studies were included in the final meta-analysis. Applying per-protocol analysis and a random-effects model, there was a significant reduction in postoperative opioid consumption and pain score in the group that received preoperative IV paracetamol, compared to placebo, as the standardized mean difference (SMD) were −0.460 (95% CI −0.828 to −0.092, p = 0.014) and −0.719 (95% CI: −1.31 to −0.13, p = 0.018), respectively. However, there was significant heterogeneity amongst the different studies included in the meta-analysis (I² = 70.66%), perhaps owing to their diverse protocols. Some studies administered IV paracetamol 15 min before induction while others gave it before surgical incision. Conclusion: This is the first review on the topic. Overall, preoperative IV paracetamol has convincingly demonstrated useful opioid-sparing effects and it also appears safe for use at the time of delivery. It should be considered as a component of an effective multimodal analgesic regimen. Future studies could be conducted on other patient groups, e.g., those with multiple comorbidities or chronic pain disorders, and further delineate the optimal timing to administer the drug preoperatively.

Regional analgesia modalities in abdominal and lower limb surgery - comparison of efficacy

A significant component of all surgical procedures and postoperative treatment is pain management.Due to the physiological and psychological advantages of pain relief, it is one of the foremost indicators of quality of care. Today, there are various modalities of pain reduction, aimed to reduce patient discomfort andminimize side effects, which can be divided by therapeutic agents used (opioid or non-opioid), route of administration (intravenous, regional, oral, etc.) and modality (controlled by patients or "as needed"). Although opioids have proven to be very effective pain relief agents and are commonly used in postoperative analgesia, concerns about their side effects have spurred the development of modified, multimodal treatments that seek to minimize opioid use and associated drawbacks. Enhanced recovery protocols that emphasize sparing administration of opioids are growing in importance, andresulting in reduced length of hospital stay after abdominal and lower limb surgery. To further improve such protocols and optimize postoperative care for individual patient needs, it is imperative to fully assess the efficacy of available drugs and analgesia modalities.

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.

Single‐dose intravenous ketorolac for acute postoperative pain in adults

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the analgesic efficacy and adverse effects of single‐dose IV ketorolac, compared with placebo or an active comparator, for moderate‐to‐severe postoperative pain in adults.

Single-dose intravenous diclofenac for acute postoperative pain in adults

BACKGROUND

Postoperative administration of non-steroidal anti-inflammatory drugs (NSAIDs) reduces patient opioid requirements and, in turn, reduces the incidence and severity of opioid-induced adverse events (AEs).

OBJECTIVES

To assess the analgesic efficacy and adverse effects of single-dose intravenous diclofenac, compared with placebo or an active comparator, for moderate to severe postoperative pain in adults.

SEARCH METHODS

We searched the following databases without language restrictions: the Cochrane Central Register of Controlled Trials (Cochrane Register of Studies Online), MEDLINE, and Embase on 22 May 2018. We checked clinical trials registers and reference lists of retrieved articles for additional studies.

SELECTION CRITERIA

We included randomized trials that compared a single postoperative dose of intravenous diclofenac with placebo or another active treatment, for treating acute postoperative pain in adults following any surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently considered trials for review inclusion, assessed risk of bias, and extracted data.Our primary outcome was the number of participants in each arm achieving at least 50% pain relief over a four- and six-hour period.Our secondary outcomes were time to, and number of participants using rescue medication; withdrawals due to lack of efficacy, AEs, and for any cause; and number of participants experiencing any AE, serious AEs (SAEs), and NSAID-related AEs. We performed a post hoc analysis of opioid-related AEs, to enable indirect comparisons with other analyses of postoperative analgesics.For subgroup analysis, we planned to analyze different doses and formulations of parenteral diclofenac separately.We assessed the overall quality of the evidence for each outcome using GRADE and created two 'Summary of findings' tables.

MAIN RESULTS

We included eight studies, involving 1756 participants undergoing various surgeries (dental, mixed minor, abdominal, and orthopedic), with 20 to 175 participants receiving intravenous diclofenac in each study. Mean study population ages ranged from 24.5 years to 54.5 years. Intravenous diclofenac doses varied among and within studies, ranging from 3.75 mg to 75 mg. Five studies assessed newer formulations of parenteral diclofenac that could be administered as an undiluted intravenous bolus. Most studies had an unclear risk of bias for several domains and a high risk of bias due to small sample size. The overall quality of evidence for each outcome was generally low for reasons including unclear risk of bias in studies, imprecision, and low event numbers.Primary outcomeThree studies (277 participants) produced a number needed to treat for an additional beneficial outcome (NNTB) for at least 50% of maximum pain relief versus placebo of 2.4 (95% confidence interval (CI) 1.9 to 3.1) over four hours (low-quality evidence). Four studies (436 participants) produced an NNTB of 3.8 versus placebo (95% CI 2.9 to 5.9) over six hours (low-quality evidence). No studies provided data for the comparison of intravenous diclofenac with another NSAID over four hours. At six hours there was no difference between intravenous diclofenac and another NSAID (low-quality evidence).Secondary outcomesFor secondary efficacy outcomes, intravenous diclofenac was generally superior to placebo and similar to other NSAIDs.For time to rescue medication, comparison of intravenous diclofenac versus placebo demonstrated a median of 226 minutes for diclofenac versus 80 minutes for placebo (5 studies, 542 participants, low-quality evidence). There were insufficient data for pooled analysis for comparisons of diclofenac with another NSAID (very low-quality evidence).For the number of participants using rescue medication, two studies (235 participants) compared diclofenac with placebo. The number needed to treat to prevent one additional harmful event (NNTp) (here, the need for rescue medication) compared with placebo was 3.0 (2.2 to 4.5, low-quality evidence). The comparison of diclofenac with another NSAID included only one study (98 participants). The NNTp was 4.5 (2.5 to 33) for ketorolac versus diclofenac (very low-quality evidence).The numbers of participants withdrawing were generally low and inconsistently reported (very low-quality evidence). Participant withdrawals were: 6% (8/140) diclofenac versus 5% (7/128) placebo, and 9% (8/87) diclofenac versus 7% (6/82) another NSAID for lack of efficacy; 2% (4/211) diclofenac versus 0% (0/198) placebo, and 3% (4/138) diclofenac versus 2% (2/129) another NSAID due to AEs; and 11% (21/191) diclofenac versus 17% (30/179) placebo, and 18% (21/118) diclofenac versus 15% (17/111) another NSAID for any cause.Overall adverse event rates were similar between intravenous diclofenac and placebo (71% in both groups, 2 studies, 296 participants) and between intravenous diclofenac and another NSAID (55% and 58%, respectively, 2 studies, 265 participants) (low-quality evidence for both comparisons). Serious and specific AEs were rare, preventing meta-analysis.There were sufficient data for a dose-effect analysis for our primary outcome for only one alternative dose, 18.75 mg. Analysis of the highest dose employed in each study demonstrated a relative benefit compared with placebo of 1.9 (1.4 to 2.4), whereas for the group receiving 18.75 mg, the relative benefit versus placebo was 1.6 (1.2 to 2.1, 2 studies). Compared to another NSAID, the high-dose analysis demonstrated a relative benefit of 0.9 (0.8 to 1.1), for the group receiving 18.75 mg, the relative benefit was 0.78 (0.65 to 0.93). For direct comparison of high dose versus 18.75 mg, the proportion of participants with at least 50% pain relief was 66% (90/137) for the high-dose arm versus 57% (77/135) in the low-dose arm. There were insufficient data for subgroup meta-analysis of different diclofenac formulations.

AUTHORS' CONCLUSIONS

The amount and quality of evidence for the use of intravenous diclofenac as a treatment for postoperative pain is low. The available evidence indicates that postoperative intravenous diclofenac administration offers good pain relief for the majority of patients, but further research may impact this estimate. Adverse events appear to occur at a similar rate to other NSAIDs. Insufficient information is available to assess whether intravenous diclofenac has a different rate of bleeding, renal dysfunction, or cardiovascular events versus other NSAIDs. There was insufficient information to evaluate the efficacy and safety of newer versus traditional formulations of intravenous diclofenac. There was a lack of studies in major and cardiovascular surgeries and in elderly populations, which may be at increased risk for adverse events.

Paravertebral blocks and enhanced recovery after surgery protocols in breast reconstructive surgery: patient selection and perspectives

The management of postoperative pain is of critical importance for women undergoing breast reconstruction after surgical treatment for breast cancer. Mitigating postoperative pain can improve health-related quality of life, reduce health care resource utilization and costs, and minimize perioperative opiate use. Multimodal analgesia pain management strategies with nonopioid analgesics have improved the value of surgical care in patients undergoing various operations but have only recently been reported in reconstructive breast surgery. Regional anesthesia techniques, with paravertebral blocks (PVBs) and transversus abdominis plane (TAP) blocks, and enhanced recovery after surgery (ERAS) pathways have been increasingly utilized in opioid-sparing multimodal analgesia protocols for women undergoing breast reconstruction. The objectives of this review are to 1) comprehensively review regional anesthesia techniques in breast reconstruction, 2) outline important components of ERAS protocols in breast reconstruction, and 3) provide evidence-based recommendations regarding each intervention included in these protocols. The authors searched across six databases to identify relevant articles. For each perioperative intervention included in the ERAS protocols, the literature was exhaustively reviewed and evidence-based recommendations were generated using the Grading of Recommendations, Assessment, Development, and Evaluation system methodology. This study provides a comprehensive evidence-based review of interventions to optimize perioperative care and postoperative pain control in breast reconstruction. Incorporating evidence-based interventions into future ERAS protocols is essential to ensure high value care in breast reconstruction.

A pilot study of a breast surgery Enhanced Recovery After Surgery (ERAS) protocol to eliminate narcotic prescription at discharge

BACKGROUND

The evolving conceptualization of the management of surgical pain was a major contributor to the supply of narcotics that led to the opioid crisis. We designed and implemented a breast surgery-specific Enhanced Recovery After Surgery (ERAS) protocol using opioid-sparing techniques to eliminate narcotic prescription at discharge without sacrificing perioperative pain control.

METHODS

A pilot observational study included patients with and without cancer undergoing lumpectomy. The convenience sample consisted of an ERAS group and a control usual care (UC) group who underwent surgery during the same time period. Discharge narcotic prescriptions were compared after converting to oral morphine milligram equivalents (MME's). Postoperative day one and week one pain scores were also compared between the two groups.

RESULTS

Ninety ERAS and 67 UC patients were enrolled. Most lumpectomies were wire-localized, and half of the patients in each group had breast cancer. There were more obese patients in the ERAS group. UC lumpectomy patients were discharged with a median of 54.5 MMEs (range 0-120), while the ERAS lumpectomy patients were discharged with none (p < 0.001). Postoperative pain scores were not significantly different between groups, and there were few complications.

CONCLUSION

A breast surgery-specific ERAS protocol employing opioid-sparing techniques successfully eliminated postoperative narcotic prescription without sacrificing perioperative pain control or increasing postoperative complications. By promoting the adoption of similar protocols, surgeons can continue to improve patient outcomes while decreasing the quantity of narcotics available for diversion within our patients' communities.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Importance of Optimizing Acute Pain in the Orthopedic Trauma Patient

Postoperative pain control is a highly studied topic because of its significant effect on costs, hospital course, and, most importantly, patient satisfaction. Opioid use has been the "status quo" of postoperative pain management but prolongs hospital stays and increases complications. Optimizing acute pain management in patients with orthopedic trauma is important and can translate into significant positive physiologic and financial outcomes. Although multiple viable examples of optimizing acute pain management in the literature demonstrate outcome improvements, implementation has not been widespread. Significant outcome success will depend more on systemwide implementation than a specific regimen for postoperative pain control.

Oral paracetamol (acetaminophen) for cancer pain

BACKGROUND

Pain is a common symptom with cancer, and 30% to 50% of all people with cancer will experience moderate to severe pain that can have a major negative impact on their quality of life. Non-opioid drugs are commonly used to treat mild to moderate cancer pain, and are recommended for this purpose in the WHO cancer pain treatment ladder, either alone or in combination with opioids.A previous Cochrane review that examined the evidence for nonsteroidal anti-inflammatory drugs (NSAIDs) or paracetamol, alone or combined with opioids, for cancer pain was withdrawn in 2015 because it was out of date; the date of the last search was 2005. This review, and another on NSAIDs, updates the evidence.

OBJECTIVES

To assess the efficacy of oral paracetamol (acetaminophen) for cancer pain in adults and children, and the adverse events reported during its use in clinical trials.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from inception to March 2017, together with reference lists of retrieved papers and reviews, and two online study registries.

SELECTION CRITERIA

We included randomised, double-blind, studies of five days' duration or longer, comparing paracetamol alone with placebo, or paracetamol in combination with an opioid compared with the same dose of the opioid alone, for cancer pain of any intensity. Single-blind and open studies were also eligible for inclusion. The minimum study size was 25 participants per treatment arm at the initial randomisation.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. We did not carry out any pooled analyses. We assessed the quality of the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

Three studies in adults satisfied the inclusion criteria, lasting up to one week; 122 participants were randomised initially, and 95 completed treatment. We found no studies in children. One study was parallel-group, and two had a cross-over design. All used paracetamol as an add-on to established treatment with strong opioids (median daily morphine equivalent doses of 60 mg, 70 mg, and 225 mg, with some participants taking several hundred mg of oral morphine equivalents daily). Other non-paracetamol medication included non-steroidal anti-inflammatory drugs (NSAIDs), tricyclic antidepressants, or neuroleptics. All studies were at high risk of bias for incomplete outcome data and small size; none was unequivocally at low risk of bias.None of the studies reported any of our primary outcomes: participants with pain reduction of at least 50%, and at least 30%, from baseline; participants with pain no worse than mild at the end of the treatment period; participants with Patient Global Impression of Change (PGIC) of much improved or very much improved (or equivalent wording). What pain reports there were indicated no difference between paracetamol and placebo when added to another treatment. There was no convincing evidence of paracetamol being different from placebo with regards to quality of life, use of rescue medication, or participant satisfaction or preference. Measures of harm (serious adverse events, other adverse events, and withdrawal due to lack of efficacy) were inconsistently reported and provided no clear evidence of difference.Our GRADE assessment of evidence quality was very low for all outcomes, because studies were at high risk of bias from several sources.

AUTHORS' CONCLUSIONS

There is no high-quality evidence to support or refute the use of paracetamol alone or in combination with opioids for the first two steps of the three-step WHO cancer pain ladder. It is not clear whether any additional analgesic benefit of paracetamol could be detected in the available studies, in view of the doses of opioids used.

Safety and Efficacy of Intra-articular Injection of Platelet-Rich Plasma in Patients With Ankle Osteoarthritis

BACKGROUND

An intra-articular injection of platelet-rich plasma (PRP) may be an effective treatment for osteoarthritis (OA). However, its efficacy in ankle OA has not been investigated yet. The purpose of this study was to assess the safety and efficacy of an intra-articular injection of PRP in patients with ankle OA during a 24-week period.

METHODS

Twenty ankles of 20 patients with varus-type ankle OA who received intra-articular injections of PRP were evaluated. PRP was extracted from whole blood by using the double-spin technique. Three injections of 2-mL PRP were administered to the ankle at an interval of 2 weeks under ultrasonographic guidance. Adverse events and efficacy were assessed at 4, 12, and 24 weeks after the last injection. Clinical outcomes were assessed by using the visual analog scale (VAS) for pain, the Japanese Society for Surgery of the Foot (JSSF) ankle/hindfoot scale, and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q).

RESULTS

No serious adverse effects were observed during the follow-up period. The VAS and JSSF scale scores significantly decreased from baseline to 4, 12, and 24 weeks after treatment ( P < .001). The mean score in the pain-related subscale of the SAFE-Q significantly improved from baseline to 12 weeks after treatment ( P = .04). Overall, the amount of pain reduction was maximal at 12 weeks after the last injection, and the effect was reduced at 24 weeks. The patients with late-stage OA had worse scores in all outcomes than those with early-stage OA.

CONCLUSION

Intra-articular injections of PRP resulted in no serious adverse effects and significantly reduced pain in the patients with ankle OA. PRP treatment can be safe and effective and may be an option in the treatment of ankle OA.

LEVEL OF EVIDENCE

Level IV, case series.

Single dose oral ketoprofen or dexketoprofen for acute postoperative pain in adults

BACKGROUND

This review is an update of "Single dose oral ketoprofen and dexketoprofen for acute postoperative pain in adults" last updated in Issue 4, 2009. Ketoprofen is a non-selective nonsteroidal anti-inflammatory drug (NSAID) used to treat acute and chronic painful conditions. Dexketoprofen is the (S)-enantiomer, which is believed to confer analgesia. Theoretically dexketoprofen is expected to provide equivalent analgesia to ketoprofen at half the dose, with a consequent reduction in gastrointestinal adverse events. This review is one of a series on oral analgesics for acute postoperative pain. Individual reviews have been brought together in two overviews to provide information about the relative efficacy and harm of the different interventions.

OBJECTIVES

To assess the efficacy and safety of single dose oral ketoprofen and oral dexketoprofen compared with placebo for acute postoperative pain, using methods that permit comparison with other analgesics evaluated in the same way, and criteria of efficacy recommended by an in-depth study at the individual patient level.

SEARCH METHODS

For this update, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from 2009 to 28 March 2017. We also searched the reference lists of retrieved studies and reviews, and two online clinical trial registries.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled trials of single dose orally administered ketoprofen or dexketoprofen in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered studies for inclusion in the review, examined issues of study quality and potential bias, and extracted data. For dichotomous outcomes, we calculated risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNT) or harmful outcome (NNH) with 95% confidence intervals (CI) for ketoprofen and dexketoprofen, compared with placebo, where there were sufficient data. We collected information on the number of participants with at least 50% of the maximum possible pain relief over six hours, the median time to use of rescue medication, and the proportion of participants requiring rescue medication. We also collected information on adverse events and withdrawals. We assessed the quality of the evidence using GRADE, and created 'Summary of findings' tables.

MAIN RESULTS

This updated review included 24 studies; six additional studies added 1001 participants involved in comparisons of ketoprofen or dexketoprofen and placebo, with a 12% increase in participants taking ketoprofen and a 65% increase for dexketoprofen. Most participants (70%) were women. Dental studies typically involved young participants (mean age 20 to 30 years); other types of surgery involved older participants (mean age 37 to 68 years). Overall, we judged the studies at high risk of bias only for small size, which can lead to an overestimation of benefit.Ketoprofen doses ranged between 6.5 mg and 150 mg. The proportion of participants achieving at least 50% pain relief over six hours with the usual ketoprofen oral dose of 50 mg was 57%, compared to 23% with placebo, giving an NNT of 2.9 (95% CI 2.4 to 3.7) (RR 2.5, 95% CI 2.0 to 3.1; 594 participants; 8 studies; high quality evidence). Efficacy was significantly better in dental studies (NNT 1.8) than other surgery (NNT 4.2). The proportion of participants using rescue medication within six hours was lower with ketoprofen (32%) than with placebo (75%), giving a number needed to treat to prevent use of rescue medication (NNTp) of 2.3 (95% CI 1.8 to 3.1); 263 participants; 4 studies; high quality evidence). Median time to remedication estimates were poorly reported. Reports of any adverse event were similar with ketoprofen (18%) and placebo (11%) (RR 1.6, 95% CI 0.98 to 2.8; 342 participants; 5 studies; high quality evidence). No study reported any serious adverse events (very low quality evidence).Dexketoprofen doses ranged between 5 mg and 100 mg. The proportion of participants achieving at least 50% pain relief over six hours with the usual dexketoprofen oral dose of 20 mg or 25 mg was 52%, compared to 27% with placebo, giving an NNT of 4.1 (95% CI 3.3 to 5.2) (RR 2.0, 95% CI 1.6 to 2.2; 1177 participants; 8 studies; high quality evidence). Efficacy was significantly better in dental studies (NNT 2.7) than other surgery (NNT 5.7). The proportion of participants using rescue medication within six hours was lower with dexketoprofen (47%) than placebo (69%), giving an NNTp of 4.7 (95% CI 3.3 to 8.0); 445 participants; 5 studies; high quality evidence). Median time to remedication estimates were poorly reported. Reports of any adverse event were similar with dexketoprofen (14%) and placebo (10%) (RR 1.4, 95% CI 0.89 to 2.2; 536 participants, 6 studies; high quality evidence). No study reported any serious adverse events (very low quality evidence).

AUTHORS' CONCLUSIONS

Ketoprofen at doses of 25 mg to 100 mg is an effective analgesic in moderate to severe acute postoperative pain with an NNT for at least 50% pain relief of 2.9 with a 50 mg dose. This is similar to that of commonly used NSAIDs such as ibuprofen (NNT 2.5 for 400 mg dose) and diclofenac (NNT 2.7 for 50 mg dose). Dexketoprofen is also effective with an NNT of 4.1 in the dose range 10 mg to 25 mg. Differential efficacy between dental surgery and other types of surgery seen for both drugs is unusual. Both drugs were well tolerated in single doses.

American Society for Enhanced Recovery (ASER) and Perioperative Quality Initiative (POQI) joint consensus statement on optimal analgesia within an enhanced recovery pathway for colorectal surgery: part 1-from the preoperative period to PACU

Background

Within an enhanced recovery pathway (ERP), the approach to treating pain should be multifaceted and the goal should be to deliver “optimal analgesia,” which we define in this paper as a technique that optimizes patient comfort and facilitates functional recovery with the fewest medication side effects.

Methods

With input from a multi-disciplinary, international group of clinicians, and through a structured review of the literature and use of a modified Delphi method, we achieved consensus surrounding the topic of optimal analgesia in the perioperative period for colorectal surgery patients.

Discussion

As a part of the first Perioperative Quality Improvement (POQI) workgroup meeting, we sought to develop a consensus document describing a comprehensive, yet rational and practical, approach for developing an evidence-based plan for achieving optimal analgesia, specifically for a colorectal surgery ERP. The goal was two-fold: (a) that application of this process would lead to improved patient outcomes and (b) that investigation of the questions raised would identify knowledge gaps to aid the direction for research into analgesia within ERPs in the years to come. This document details the evidence for a wide range of analgesic components, with particular focus from the preoperative period to the post-anesthesia care unit. The overall conclusion is that the combination of analgesic techniques employed in the perioperative period is not important as long as it is effective in delivering the goal of optimal analgesia as set forth in this document.

American Society for Enhanced Recovery (ASER) and Perioperative Quality Initiative (POQI) Joint Consensus Statement on Optimal Analgesia within an Enhanced Recovery Pathway for Colorectal Surgery: Part 2-From PACU to the Transition Home

BACKGROUND

Within an enhanced recovery pathway (ERP), the approach to treating pain should be multifaceted and the goal should be to deliver "optimal analgesia", which we define in this paper as a technique that optimizes patient comfort and facilitates functional recovery with the fewest medication side effects.

METHODS

With input from a multidisciplinary, international group of experts and through a structured review of the literature and use of a modified Delphi method, we achieved consensus surrounding the topic of optimal analgesia in the perioperative period for colorectal surgery patients.

DISCUSSION

As a part of the first Perioperative Quality Improvement (POQI) workgroup meeting, we sought to develop a consensus document describing a comprehensive, yet rational and practical, approach for developing an evidence-based plan for achieving optimal analgesia, specifically for a colorectal surgery within an ERP. The goal was twofold: (a) that application of this process would lead to improved patient outcomes and (b) that investigation of the questions raised would identify knowledge gaps to aid the direction for research into analgesia within ERPs in the years to come. This document details the evidence for a wide range of analgesic components, with particular focus on care in the post-anesthesia care unit, general care ward, and transition to home after discharge. The preoperative and operative consensus statement for analgesia was covered in Part 1 of this paper. The overall conclusion is that the combination of analgesic techniques employed in the perioperative period is not important as long as it is effective in delivering the goal of "optimal analgesia" as set forth in this document.

Single dose intravenous diclofenac for acute postoperative pain in adults

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the analgesic efficacy and adverse effects of a single dose of intravenous diclofenac, compared with placebo or an active comparator, for moderate to severe postoperative pain in adults.

Paracetamol (acetaminophen) with or without codeine or dihydrocodeine for neuropathic pain in adults

BACKGROUND

Paracetamol, either alone or in combination with codeine or dihydrocodeine, is commonly used to treat chronic neuropathic pain. This review sought evidence for efficacy and harm from randomised double-blind studies.

OBJECTIVES

To assess the analgesic efficacy and adverse events of paracetamol with or without codeine or dihydrocodeine for chronic neuropathic pain in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from inception to July 2016, together with reference lists of retrieved papers and reviews, and two online study registries.

SELECTION CRITERIA

We included randomised, double-blind studies of two weeks' duration or longer, comparing paracetamol, alone or in combination with codeine or dihydrocodeine, with placebo or another active treatment in chronic neuropathic pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. We did not carry out any pooled analyses. We assessed the quality of the evidence using GRADE.

MAIN RESULTS

No study satisfied the inclusion criteria. Effects of interventions were not assessed as there were no included studies. We have only very low quality evidence and have no reliable indication of the likely effect.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support or refute the suggestion that paracetamol alone, or in combination with codeine or dihydrocodeine, works in any neuropathic pain condition.

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.

Single fixed-dose oral dexketoprofen plus tramadol for acute postoperative pain in adults

BACKGROUND

Combining two different analgesics in fixed doses in a single tablet can provide better pain relief than either drug alone in acute pain. This appears to be broadly true across a range of different drug combinations, in postoperative pain and migraine headache. A new combination of dexketoprofen (a nonsteroidal anti-inflammatory drug) plus tramadol (an opioid) has been tested in acute postoperative pain conditions. It is not yet licensed for use. This review is one of a series on oral analgesics for acute postoperative pain. Individual reviews have been brought together in two overviews to provide information about the relative efficacy and harm of the different interventions.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of a single fixed-dose of oral dexketoprofen plus tramadol, compared with placebo, for moderate to severe postoperative pain in adults, using methods that permit comparison with other analgesics evaluated in standardised trials using almost identical methods and outcomes. A secondary objective was to compare the combination with the individual analgesics alone.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) via CRSO, MEDLINE via Ovid, and Embase via Ovid from inception to 31 May 2016. We also searched the reference lists of retrieved studies and reviews, and two online clinical trial registries.

SELECTION CRITERIA

Randomised, double-blind trials of oral dexketoprofen plus tramadol administered as a single oral dose, for the relief of acute postoperative pain in adults, and compared to placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered trials for inclusion in the review, examined issues of study quality and potential bias, and extracted data. For dichotomous outcomes, we calculated risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNT) for dexketoprofen plus tramadol, compared with placebo with 95% confidence intervals (CI). We collected information on the number of participants with at least 50% of the maximum possible pain relief over six hours, the median time to use of rescue medication, and the proportion of participants requiring rescue medication. We also collected information on adverse events and withdrawals. We assessed the quality of the evidence using GRADE and created a 'Summary of findings' table.We also collected information on the number of participants with at least 50% of the maximum possible pain relief over six hours for dexketoprofen alone and tramadol alone.

MAIN RESULTS

We included three studies with 1853 participants who had undergone surgical removal of impacted wisdom teeth, hip replacement, or hysterectomy. The overall risk of bias across the three included studies was low, with unclear risk of bias in relation to the size of the three studies. Two studies did not report all our prespecified outcomes, which limited the analyses we could do.The proportion of participants achieving at least 50% pain relief over six hours with dexketoprofen 25 mg plus tramadol 75 mg was 66%, compared to 32% with placebo, giving an NNT of 3.0 (95% CI 2.5 to 3.7) (RR 2.1 (95% CI 1.7 to 2.4); 748 participants; 3 studies) (moderate quality evidence). The response rate with dexketoprofen 25 mg alone was 53% (RR 1.3 (95% CI 1.1 to 1.4); 744 participants; 3 studies) and with tramadol alone was 45% (RR 1.5 (95% CI 1.3 to 1.7); 741 participants; 3 studies) (moderate quality evidence). We downgraded the evidence because of some inconsistency in the results.The median time to use of rescue medication could not be estimated exactly, but was probably eight hours or more, indicating a long duration of effect (moderate quality evidence). We downgraded the evidence because it was not possible to estimate the effect exactly in the two multiple dose studies, resulting in imprecision. Fewer participants used rescue medication with higher doses of active treatment (summary statistic not calculated; 123 participants; 1 study) (very low quality evidence). We downgraded the evidence because the data came from a single study with few participants and events.Adverse events and serious adverse events were not reported consistently for the single dose phase of the studies. In the single dose study, 11% of participants experienced adverse events with dexketoprofen 25 mg plus tramadol 75 mg, which were mostly mild or moderate nausea, vomiting, or dizziness, and typical with these medicines. Rates were lower with placebo and lower doses (very low quality evidence). We downgraded the evidence because the data came from a single study with few participants and events. Information on multiple dosing over three and five days supported a low event rate with the combination. Overall, rates were generally low in all treatment arms, as they were for withdrawals for adverse events or other reasons.

AUTHORS' CONCLUSIONS

A single oral dose of dexketoprofen 25 mg plus tramadol 75 mg provided good levels of pain relief with long duration of action to more people than placebo or the same dose of dexketoprofen or tramadol alone. The magnitude of the effect was similar to other good analgesics. Adverse event rates were low.There is modest uncertainty about the precision of the point estimate for efficacy, but the NNT of 3 is consistent with other analgesics considered effective and commonly used.

A Randomized Controlled Trial Comparing Two Multimodal Analgesic Techniques in Patients Predicted to Have Severe Pain After Cesarean Delivery

BACKGROUND

Improved pain control after cesarean delivery remains a challenging objective. Poorly treated acute pain following delivery is associated with an increased risk of chronic pain and depression. This study was conducted to determine whether the addition of systemic acetaminophen and an increased dose of intrathecal morphine would further reduce acute pain. The primary outcome was pain intensity with movement at 24 hours postoperatively. Secondary measures included persistent pain and depression at 8 weeks.

METHODS

Seventy-four parturients scheduled for elective cesarean delivery under spinal anesthesia that were predicted to be above the 80th percentile for evoked pain intensity based on a 3-item preoperative screening questionnaire were enrolled. Patients in the intervention group received 300 mcg spinal morphine and 1 gram acetaminophen every 6 hours for 24 hours postoperatively. Patients in the control group received 150 mcg spinal morphine and placebo tablets. All patients received scheduled ibuprofen by mouth and IV morphine patient-controlled analgesia. At 24 hours, patients rated their pain intensity with movement, at rest, on average, and worst score using a visual analog scale for pain (100-mm unmarked line). The presence of persistent pain and depression was assessed at 8 weeks using the Edinburgh postpartum depression survey.

RESULTS

Providing a higher dose of spinal morphine combined with systemic acetaminophen to patients predicted to be at high risk for severe post-cesarean delivery pain significantly reduced evoked pain scores with movement at 24 hours (mean ± SD: 46 ± 25 mm in control group versus 31 ±17 mm in intervention group, P = 0.009; 95% confidence interval for the difference between means: 4 mm, 26 mm). There was no difference in the incidence of persistent pain (13% (4/30) in control group versus 10% (3/30) in intervention group, P > 0.99), or depression at 8 weeks postoperatively (10% (3/30) in control group versus 13% (4/30) in intervention group, P > 0.99).

CONCLUSIONS

Adding a higher dose of intrathecal morphine and oral acetaminophen to a multimodal pain regimen in patients predicted to be at risk for high acute postpartum pain after cesarean delivery results in a significant reduction of acute postoperative pain scores at 24 hours.

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.