Reduction of opioid-related adverse events using opioid-sparing analgesia with COX-2 inhibitors lacks documentation: a systematic review

Regular use of low-dose of opioids after gastrointestinal surgery may lead to postoperative gastrointestinal tract dysfunction in children: a Chinese national regional health center experience sharing

BACKGROUND

The need for pain management is increasing in pediatrics, but the side effects of overuse or abuse of analgesics can be harmful to children's health and even life-threatening in severe cases.

METHODS

Patients who underwent resection of Meckel's diverticulum at the Children's Hospital of Chongqing Medical University from July 1, 2019, to July 1, 2022, were included in this study. Opioids were administered through patient-controlled analgesia (PCA). Based on the preoperative choices made by the legal guardians, patients were stratified into two groups: PCA Group (PCAG) and Non-PCA Group (NPCAG). Data pertaining to the clinical characteristics and prognoses of these patients were subsequently collected and analyzed to assess the impact of opioid administration.

RESULTS

In the study, a total of 126 patients were enrolled, with 72 allocated to the Patient-Controlled Analgesia Group (PCAG) and 54 to the Non-Patient-Controlled Analgesia Group (NPCAG). When compared to the NPCAG, the PCAG exhibited a longer duration of postoperative fasting (median 72 vs. 62 h, p = 0.044) and increased utilization of laxatives (12[16.7%] vs. 2[3.7%], p = 0.022). However, the PCAG also experienced higher incidences of intestinal stasis and abnormal intestinal dilation (13[18.1%] vs. 3[5.6%], p = 0.037). No statistically significant differences were observed in pain assessments at the conclusion of the surgical procedure (0 vs. 1[1.9%], p = 0.429) or within the first 24 h postoperatively (16[22.2%] vs. 18[33.3%], p = 0.164). Additionally, NPCAG patients did not necessitate increased administration of rescue analgesics (2[2.8%] vs. 4[7.4%], p = 0.432).

CONCLUSIONS

The administration of opioids did not demonstrably ameliorate postoperative pain but was associated with a heightened incidence of postoperative gastrointestinal tract dysfunction. The retrospective nature of the current research should be considered and should be clarified further.

Early perioperative versus postoperative meloxicam for pain control in patients undergoing orthopedic surgery: a systematic review and Meta-analysis of randomized controlled trials

OBJECTIVE

Post-orthopaedic operative pain is a serious concern that often requires the administration of analgesics; however, the optimal time of analgesic administration is still inconclusive. Perioperative analgesia is administrating pre-emptive analgesia before and during the surgery followed by postoperative analgesia to decrease the procedure associated nociceptive response. We aim to assess perioperative meloxicam versus postoperative meloxicam for pain control after orthopaedic operations.

METHODS

A systematic review and meta-analysis involving randomized controlled trials from PubMed, Embase, Scopus, WOS, and Cochrane until 28th May 2022. We pooled dichotomous outcomes using risk ratio (RR) presented with a 95% confidence interval (CI) and continuous outcomes using mean difference (MD) with 95% CI. We registered our protocol in PROSPERO with ID: CRD42022336046.

RESULTS

We included five RCTs with 964 patients. All the included trials showed high risk of performance and detection biases because of lack of blinding. Pooled analysis favored perioperative meloxicam in reducing pain score after six hours (MD: -0.42 with 95% CI [-0.63, -0.21], p = .0001), 12 h (MD: -0.54 with 95% CI [-0.69, -0.39], p = .00001), and 24 h (MD: -0.23 with 95% CI [-0.36, -0.10]. Pooled analysis favored perioperative meloxicam in improving patient global assessment scale after 12 h (MD: -0.66 with 95% CI [-0.86, -0.46], p = .00001), 24 h (MD: -0.30 with 95% CI [-0.49, -0.11, p = .002), and 48 h (MD: -0.17 with 95% CI [-0.33, -0.01], p = .04). Pooled analysis favored perioperative meloxicam in reducing patient-controlled analgesia (MD: -4.25 with 95% CI [-5.96, -2.54], p = .00001).

CONCLUSION

Short-term pain management after orthopaedic procedures is better accomplished with perioperative meloxicam than postoperative meloxicam. Before recommending perioperative meloxicam for pain control following orthopaedic surgeries, further multicentre trials are still warranted to examine the impact of perioperative meloxicam in different orthopaedic procedures.

Six-year trends in postoperative prescribing and use of multimodal analgesics following total hip and knee arthroplasty: A single-site observational study of pain management

BACKGROUND

Guidelines for acute postoperative pain management recommend administering analgesics in multimodal combination to facilitate synergistic benefit, reduce opioid requirements and decrease side-effects. However, limited observational research has examined the extent to which multimodal analgesics are prescribed and administered postoperatively following joint replacement.

METHODS

In this longitudinal study, we used three-point prevalence surveys to observe the 6-year trends in prescribing and use of multimodal analgesics on the orthopaedic wards of a single Australian private hospital. We collected baseline postoperative data from total hip and knee arthroplasty patients in May/June 2010 (Time 1, n = 86), and follow-up data at 1 year (Time 2, n = 199) and 5 years (Time 3, n = 188). During the follow-up, data on prescribing practices were presented to anaesthetists.

RESULTS

We found a statistically significant increase in the prescribing (p < 0.001) and use (p < 0.001) of multimodal analgesics over time. The use of multimodal analgesics was associated with lower rest pain (p = 0.027) and clinically significant reduction in interference with activities (p < 0.001) and sleep (p < 0.001). However, dynamic pain was high and rescue opioids were likely under-administered at all time points. Furthermore, while patients reported high levels of side-effects, use of adjuvant medications was low.

CONCLUSIONS

We observed significant practice change in inpatient analgesic prescribing in favour of multimodal analgesia, in keeping with contemporary recommendations. Surveys, however, appeared to identify a clinical gap in the bedside assessment and management of breakthrough pain and medication side-effects, requiring additional targeted interventions.

SIGNIFICANCE

Evaluation of 6-year trends in a large Australian metropolitan private hospital indicated substantial growth in postoperative multimodal analgesic prescribing. In the context of growing global awareness concerning multimodal analgesia, findings suggested diffusion of best-evidence prescribing into clinical practice. Findings indicated the effects of postoperative multimodal analgesia in real-world conditions outside of experimental trials. Postoperative multimodal analgesia in the clinical setting was only associated with a modest reduction in rest pain, but substantially reduced interference from pain on activities and sleep.

Assessment of the sedative effects of dexmedetomidine and propofol treatment in patients undergoing mechanical ventilation in the ICU and relationship between treatment and occurrence of ventilator-associated pneumonia and detection of pathogenic bacteria

The present study aimed to investigate the sedative effects of dexmedetomidine combined with propofol in patients undergoing mechanical ventilation in the intensive care unit (ICU), and to reveal the risk factors of ventilator-associated pneumonia (VAP). A retrospective analysis of 322 patients who had been subject to mechanical ventilation in the ICU ward was performed. Subjects were divided into two groups: A group treated with dexmedetomidine and propofol (combined group) and a group treated with dexmedetomidine alone (monotherapy group). Clinical data, sedative effects, the number of VAP patients and the distribution of VAP pathogens were assessed. Multivariate analysis and receiver operating characteristic (ROC) curves were used to predict VAP. Significant differences in the sedative effects between the two groups were observed (P<0.001). The incidence of VAP was significantly higher in the monotherapy group compared with the combined group (P<0.05). Multivariate logistic regression analysis demonstrated that age, acute physiology chronic health evaluation score, consciousness, invasive operations, recovery time, extubation time and sedation regimen were independent risk factors for VAP in the ICU during mechanical ventilation. ROC curves indicated that the areas under the curve for age, acute physiology chronic health score, consciousness, invasive operations, recovery time, extubation time and sedation regimen were 0.934, 0.870, 0.632, 0.677, 0.865, 0.950 and 0.603, respectively. In summary, dexmedetomidine combined with propofol can shorten the recovery and extubation times of mechanical ventilation patients in the ICU. Different sedation schemes are also independent risk factors for VAP during mechanical ventilation in the ICU.

Statewide Utilization of Multimodal Analgesia and Length of Stay After Colectomy

BACKGROUND

Both enhanced recovery and anesthesia literature recommend multimodal perioperative analgesia to hasten recovery, prevent adverse events, and reduce opioid use after surgery. However, adherence to, and outcomes of, these recommendations are unknown. We sought to characterize use of multimodal analgesia and its association with length of stay after colectomy.

MATERIALS AND METHODS

Within a statewide, 72-hospital collaborative quality initiative, we evaluated postoperative analgesia regimens among adult patients undergoing elective colectomy between 2012 and 2015. We used logistic regression to identify factors associated with the use of multimodal analgesia and performed multivariable linear regression to evaluate its association with postoperative length of stay (LOS).

RESULTS

Among 7265 patients who underwent elective colectomy in the study period, 4660 (64.1%) received multimodal analgesia, 2405 (33.1%) received opioids alone, and 200 (2.8%) received one nonopioid pain medication alone. Multimodal analgesia was independently associated with shorter adjusted postoperative LOS, compared with opioids alone (5.60 d [95% CI 5.38-5.81] versus 5.96 d [5.68-6.24], P = 0.016).

CONCLUSIONS

Multimodal analgesia is associated with shorter LOS, yet one-third of patients statewide received opioids alone after colectomy. As surgeons increasingly focus on our role in the opioid crisis, particularly in postdischarge opioid prescribing, we must also focus on inpatient postoperative pain management to limit opioid exposure. At the hospital level, this may have the added benefit of decreasing LOS and hastening recovery.

Impact of a remifentanil supply shortage on mechanical ventilation in a tertiary care hospital: a retrospective comparison

Background

The continuous administration of opioids in critical care patients is a common therapy for the tolerance of mechanical ventilation. Opioid choice has a crucial impact on the length of mechanical ventilation. Owing to its very short context-sensitive half-life, remifentanil widens the available options for sedoanalgetic strategies. Supply disruption of such established intensive care medication has been reported to worsen clinical outcomes.

Methods

This retrospective study investigated the influence of a nationwide supply shortage of remifentanil on mechanical ventilation and ventilation-associated outcomes at three perioperative intensive care units (ICUs) in a tertiary care hospital in Vienna. Two groups were followed: patients admitted to the ICU during the remifentanil shortage (July 1, 2016 to September 30, 2016) and a control group one year after the remifentanil shortage (July 1, 2017 to September 30, 2017). Included patients were adults, received mechanical ventilation for at least 6 h, were admitted less than 90 days in the respective ICU, and survived their admission.

Results

For comparison, Poisson count regression models and logistic regression models were computed. To compensate for multiple testing, the significance level was split (0.02 for the primary and 0.006 for secondary outcome parameters). Patients in the remifentanil shortage group received significantly longer mechanical ventilation (risk ratio 2.19, 95% confidence interval 2.14–2.24, P <0.001) with significantly prolonged ICU stay (P <0.001), days with non-invasive ventilation (P <0.001), and length of hospital stay (P <0.001). No significant difference was found in the occurrence of pneumonia (P = 0.040) and sepsis (P = 0.061). A greater proportion of patients in the shortage group underwent secondary tracheostomy (P <0.001).

Conclusions

The remifentanil shortage caused a significant impairment of essential outcome parameters in the ICU.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2198-3) contains supplementary material, which is available to authorized users.

Pain Management Strategies in Shoulder Arthroplasty

Pain control in total shoulder arthroplasty demands a multidisciplinary approach with collaboration between patients, surgeon, and anesthetist. A multimodal approach with preemptive medication, regional blockade, local anesthetics, and a combination of acetaminophen, nonsteroidal antiinflammatory drugs, tramadol, and gabapentinoids postoperatively leads to pain control and patient satisfaction. Assessment of patients' expectations constitutes a vital aspect of the preoperative patient evaluation. Educating and psychologically preparing patients reduces postoperative pain. Patients with anxiety and depression, preoperative narcotic use, and medical comorbidities are at an increased risk for suboptimal pain control. Minimizing narcotic use decreases opioid-related adverse effects and facilitates productive rehabilitation efforts.

Pain Management After Outpatient Shoulder Arthroscopy: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Effective postoperative pain management after shoulder arthroscopy is a critical component to recovery, rehabilitation, and patient satisfaction.

PURPOSE

This systematic review provides a comprehensive overview of level 1 and level 2 evidence regarding postoperative pain management for outpatient arthroscopic shoulder surgery.

STUDY DESIGN

Systematic review.

METHODS

We performed a systematic review of the various modalities reported in the literature for postoperative pain control after outpatient shoulder arthroscopy and analyzed their outcomes. Analgesic regimens reviewed include regional nerve blocks/infusions, subacromial/intra-articular injections or infusions, cryotherapy, and oral medications. Only randomized control trials with level 1 or level 2 evidence that compared 2 or more pain management modalities or placebo were included. We excluded studies without objective measures to quantify postoperative pain within the first postoperative month, subjective pain scale measurements, or narcotic consumption as outcome measures.

RESULTS

A combined total of 40 randomized control trials met our inclusion criteria. Of the 40 included studies, 15 examined nerve blocks, 4 studied oral medication regimens, 12 studied subacromial infusion, 8 compared multiple modalities, and 1 evaluated cryotherapy. Interscalene nerve blocks (ISBs) were found to be the most effective method to control postoperative pain after shoulder arthroscopy. Increasing concentrations, continuous infusions, and patient-controlled methods can be effective for more aggressively controlling pain. Dexamethasone, clonidine, intrabursal oxycodone, and magnesium have all been shown to successfully improve the duration and adequacy of ISBs when used as adjuvants. Oral pregabalin and etoricoxib administered preoperatively have evidence supporting decreased postoperative pain and increased patient satisfaction.

CONCLUSION

On the basis of the evidence in this review, we recommend the use of ISBs as the most effective analgesic for outpatient arthroscopic shoulder surgery.

Parecoxib, propacetamol, and their combination for analgesia after total hip arthroplasty: a randomized non-inferiority trial

BACKGROUND

This study assessed non-inferiority of parecoxib vs. combination parecoxib+propacetamol and compared the opioid-sparing effects of parecoxib, propacetamol, and parecoxib+propacetamol vs. placebo after total hip arthroplasty.

METHODS

In this randomized, placebo-controlled, parallel-group, non-inferiority study, patients received one of four IV treatments after surgery: parecoxib 40 mg bid (n = 72); propacetamol 2 g qid (n = 71); parecoxib 40 mg bid plus propacetamol 2 g qid (n = 72); or placebo (n = 38) with supplemental IV patient-controlled analgesia (morphine). Patients and investigators were blinded to treatment. Pain intensity at rest and with movement was assessed regularly, together with functional recovery (modified Brief Pain Inventory-Short Form) and opioid-related side effects (Opioid-Related Symptom Distress Scale) questionnaires up to 48 h.

RESULTS

After 24 h, cumulative morphine consumption was reduced by 59.8% (P < 0.001), 38.9% (P < 0.001), and 26.8% (P = 0.005) in the parecoxib+propacetamol, parecoxib, and propacetamol groups, respectively, compared with placebo. Parecoxib did not meet criteria for non-inferiority to parecoxib+propacetamol. Parecoxib+propacetamol and parecoxib significantly reduced least-squares mean pain intensity scores at rest and with movement compared with propacetamol (P < 0.05). One day after surgery, parecoxib+propacetamol significantly reduced opioid-related symptom distress and decreased pain interference with function compared with propacetamol or placebo.

CONCLUSION

Parecoxib and parecoxib+propacetamol provided significant opioid-sparing efficacy compared with placebo; non-inferiority of parecoxib to parecoxib+propacetamol was not demonstrated. Opioid-sparing efficacy was accompanied by significant reductions in pain intensity on movement, improved functional outcome, and less opioid-related symptom distress. Study medications were well tolerated.

Postoperative opioid sparing with injectable hydroxypropyl-β-cyclodextrin-diclofenac: pooled analysis of data from two Phase III clinical trials

Purpose

Use of nonopioid analgesics (including nonsteroidal anti-inflammatory drugs) for postoperative pain management can reduce opioid consumption and potentially prevent opioid-related adverse events. This study examined the postoperative opioid-sparing effect of repeated-dose injectable diclofenac formulated with hydroxypropyl-β-cyclodextrin (HPβCD)-diclofenac.

Patients and methods

Pooled data from two double-blind, randomized, placebo- and active comparator-controlled Phase III trials were analyzed. Patients received HPβCD-diclofenac, placebo, or ketorolac by intravenous injection every 6 hours for up to 5 days following abdominal/pelvic or orthopedic surgery. Rescue opioid use was evaluated from the time of first study drug administration to up to 120 hours following the first dose in the overall study population and in subgroups defined by baseline pain severity, age, and HPβCD-diclofenac dose.

Results

Overall, 608 patients received ≥1 dose of study medication and were included in the analysis. While 93.2% of patients receiving placebo required opioids, the proportion of patients requiring opioids was significantly lower for patients receiving HPβCD-diclofenac (18.75, 37.5, or 50 mg) or ketorolac (P<0.005 for all comparisons). Mean cumulative opioid dose and number of doses were significantly lower among patients receiving HPβCD-diclofenac versus placebo for the 0–24 through 0–120 hour time periods (P<0.0001), as well as versus ketorolac for the 0–72 through 0–120 hour time periods (P<0.05). HPβCD-diclofenac significantly reduced opioid consumption versus placebo in subgroups based on baseline pain severity (moderate, severe) and age (<65 years, ≥65 years) from the 0–24 hour period onward. When compared to ketorolac, HPβCD-diclofenac also significantly reduced cumulative opioid consumption among patients with moderate baseline pain (0–72 through 0–120 hours) and opioid dose number among patients ≥65 years old (0–24 through 0–120 hours).

Conclusion

HPβCD-diclofenac can reduce postoperative opioid requirements. As this analysis was not powered to compare opioid-related adverse event rates, follow-up studies examining the clinical impact of HPβCD-diclofenac’s opioid sparing are warranted.

Intravenous Acetaminophen as an Adjunct Analgesic in Cardiac Surgery Reduces Opioid Consumption But Not Opioid-Related Adverse Effects: A Randomized Controlled Trial

OBJECTIVES

The authors hypothesized that intravenous acetaminophen as an adjunct analgesic would significantly decrease 24-hour postoperative opioid consumption.

DESIGN

Double-blind, randomized, placebo-controlled trial.

SETTING

A single academic medical center.

PARTICIPANTS

The study was comprised of 68 adult patients undergoing cardiac surgery.

INTERVENTIONS

Patients were assigned randomly to receive either 1,000 mg of intravenous acetaminophen or placebo immediately after anesthesia induction, at the end of surgery, and then every 6 hours for the first 24 hours in the intensive care unit, for a total of 6-1,000 mg doses.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was 24-hour postoperative opioid consumption. The secondary outcomes included 48-hour postoperative opioid consumption, incisional pain scores, opioid-related adverse effects, length of mechanical ventilation, length of intensive care unit stay, and the extent of wound hyperalgesia assessed at 24 and 48 hours postoperatively. The mean±standard deviation postoperative 24-hour opioid consumption expressed in morphine equivalents was significantly less in the acetaminophen group (45.6±29.5 mg) than in the placebo group (62.3±29.5 mg), representing a 27% reduction in opioid consumption (95% CI, 2.3-31.1 mg; p = 0.024). There were no differences in pain scores and opioid-related adverse effects between the 2 groups. A significantly greater number of patients in the acetaminophen group responded "very much" and "extremely well" when asked how their overall pain experience met their expectation (p = 0.038).

CONCLUSIONS

The administration of intravenous acetaminophen during cardiac surgery and for the first 24 hours postoperatively reduced opioid consumption and improved patient satisfaction with their overall pain experience but did not reduce opioid side effects.

An Overview of Pharmacologic Management of Chronic Pain

Patients with chronic pain can be challenging to manage and historically providers have relied on opiates to treat pain. Recent studies have brought into question the safety and efficacy of chronic opiate therapy in the noncancer population. There is a vast amount of literature to support the use of nonsteroidal anti-inflammatory medications, antidepressants, anticonvulsants, topical agents, cannabinoids, and botulinum toxin either in conjunction with or in lieu of opioids. Intrathecal drug delivery systems can deliver some of these medications directly to their primary site of action while minimizing the side effects seen with systemic administration.

Effects of parecoxib on analgesia benefit and blood loss following open prostatectomy: a multicentre randomized trial

Background

This multi-centre, prospective, randomized, double-blind, placebo-controlled study was designed to test the hypotheses that parecoxib improves patients’ postoperative analgesia without increasing surgical blood loss following radical open prostatectomy.

Methods

105 patients (64 ± 7 years old) were randomized to receive either parecoxib or placebo with concurrent morphine patient controlled analgesia. Cumulative opioid consumption (primary objective) and the overall benefit of analgesia score (OBAS), the modified brief pain inventory short form (m-BPI-sf), the opioid-related symptom distress scale (OR-SDS), and perioperative blood loss (secondary objectives) were assessed.

Results

In each group 48 patients received the study medication for 48 hours postoperatively. Parecoxib significantly reduced cumulative opioid consumption by 24% (43 ± 24.1 mg versus 57 ± 28 mg, mean ± SD, p=0.02), translating into improved benefit of analgesia (OBAS: 2(0/4) versus 3(1/5.25), p=0.01), pain severity (m-BPI-sf: 1(1/2) versus 2(2/3), p < 0.01) and pain interference (m-BPI-sf: 1(0/1) versus 1(1/3), p=0.001), as well as reduced opioid-related side effects (OR-SDS score: 0.3(0.075/0.51) versus 0.4(0.2/0.83), p=0.03). Blood loss was significantly higher at 24 hours following surgery in the parecoxib group (4.3 g⋅dL⁻¹ (3.6/4.9) versus (3.2 g⋅dL⁻¹ (2.4/4.95), p=0.02).

Conclusions

Following major abdominal surgery, parecoxib significantly improves patients’ perceived analgesia. Parecoxib may however increase perioperative blood loss. Further trials are needed to evaluate the effects of selective cyclooxygenase-2 inhibitors on blood loss.

Trial registration

ClinicalTrials.gov Identifier: NCT00346268

Early adjuvant use of nonopioids associated with reduced odds of serious postoperative opioid adverse events and need for rescue in children

OBJECTIVES

Examine factors associated with opioid adverse drug events (ADE) in children.

SPECIFIC AIMS

Examine whether adjuvant nonopioid use is associated with a decreased probability of opioid-ADEs and need for rescue.

BACKGROUND

Opioid-ADEs contribute to serious preventable harm for hospitalized children. Adjuvant nonopioid use may mitigate opioid risk postoperatively, yet few studies support this notion.

METHOD

This nested case-control study included children who required intervention or rescue from opioid-ADEs and procedure-matched controls. Data were recorded from medical records and primary outcomes included serious opioid-ADEs (over-sedation and respiratory depression) and need for rescue (e.g., naloxone, rapid response team). Hierarchical logistic regression (HLR) models examined relationships between factors and opioid-ADEs. Early clinical signs and symptoms of deterioration were examined.

RESULTS

Twenty five children with opioid-ADEs and 98 children without events were included. ASA-PS remained an independent risk factor (odds ratio, 2.56 [1.09, 6.03]; P = 0.031), while adjuvant nonopioids a risk reduction factor for opioid-ADEs (OR, 0.16 [0.05, 0.47]; P = 0.001) and need for rescue (0.14 [0.04, 0.47]; P = 0.001). Supplemental oxygen use at PACU discharge was associated with an increased odds of opioid-ADEs (OR, 3.72 [1.35, 10.23]; P = 0.007) and need for rescue (5.5 [1.7, 17.82]; P = 0.002).

CONCLUSIONS

Findings from this study suggest that strategies such as early use of adjuvant nonopioids may reduce risk of opioid-ADEs postoperatively. Furthermore, children who require supplemental oxygen early postoperatively may be at heightened risk of later events.

Room for improvement: unmet needs in postoperative pain management

Postoperative pain treatment is an important healthcare issue. However, the management of pain in patients after surgery remains insufficient. In the present review, several key areas important for postoperative pain management are discussed. New findings about efficacy and side effects of nonopioid analgesics, such as paracetamol, NSAIDs and COX-2 inhibitors, are presented and discussed in light of acute, short-term application in the perioperative period. Second, new findings about postoperative pain management in patients with preoperative pain and chronic opioid consumption are reported. Third, feasibility of the transversus abdominal plane block as a new and promising regional anesthesia technique is discussed. Finally, potential predictors, mechanisms and preventive treatment strategies of persistent chronic pain after surgery are presented.

A review of opioids for in-hospital pain management

In the postoperative pain setting, the use of opioid analgesics remains essential in achieving effective analgesia and in avoiding the deleterious sequelae of uncontrolled pain that can worsen patient outcomes. However, postoperative pain remains undertreated in many patients. Choosing the most appropriate use of opioids in the postoperative setting, especially for patients undergoing ongoing opioid treatment for chronic pain, can pose daunting challenges for many clinicians. In this article, we examine the pitfalls that may be encountered when implementing postoperative pain management strategies with opioid analgesics, especially in patients receiving chronic opioid therapy prior to admission, and the critical steps for appropriate and effective analgesia in this setting.

[Concepts for perioperative pain therapy. A critical stocktaking]

Despite numerous publications, new guidelines for the treatment of acute pain and efforts from a number of initiatives, there is still a tremendous need for improvement in postoperative pain therapy. One of the reasons for the shortcomings in the care of patients with postoperative pain is the lack of applicability of guidelines in daily clinical practice. Therefore, simple but effective and easy to implement concepts need to be developed. In the following review, different concepts that have been developed over recent years are presented and evaluated for their effectiveness. One of these is the notion of balanced analgesia, currently probably one of the most widely used perioperative therapy concepts. The idea of this concept is to reduce the doses of analgesics, e.g. opioids, through combinations of different classes of analgesics, thereby reducing their side effects. However, recent studies and essential meta-analyses indicate pitfalls using this concept. The pros and cons will be discussed and ideas on how to deal with balanced analgesia in daily practice will be given. Another pain concept of "procedure-specific postoperative pain therapy", is an appealing idea of an international initiative from surgeons and anaesthesiologists and an essential part of the German S3 guidelines for acute pain released last year. Critical evaluation of the available recommendations for procedure-specific analgesia together with the presentation of relatively simple but evidence-based algorithms for specific procedures may help to implement this concept in clinical routine.

Multimodal analgesia for hip arthroplasty

Multimodal analgesia incorporates the use of analgesic adjuncts with different mechanisms of action to enhance postoperative pain management. Acetaminophen, anti-inflammatories, and gabapentinoids provide effective analgesia while reducing opioid requirements and opioid-related side effects. Intrathecal morphine and periarticular local anesthetic infiltration further enhance dynamic analgesia and improve postoperative mobilization. Epidural analgesia, peripheral nerve blocks, tramadol, ketamine, and/or clonidine can be added for improved benefit in opioid-tolerant individuals.

[New substances and applications for postoperative pain therapy]

The onset of postoperative pain is the result of various pathophysiological mechanisms and depends on the type of surgery performed. Therefore, any adequate postoperative pain treatment requires multimodal and procedure-specific analgesia. In addition to reducing perioperative complications and improving patient comfort, optimal postoperative pain management also represents an important quality characteristic which can influence the patient in their choice of hospital. In the past 1-2 years, known groups of substances have been rediscovered for postoperative pain therapy (e.g., Gabapentin and Pregabalin, i.v. Lidocaine, Ketamine or glucocorticoids), while new substances (coxibe, oral oxycodone+naloxone) and applications have been developed. The present overview article discusses the advantages and disadvantages of these substances and analgesic methods, as well as their specific areas of application.

Perioperative celecoxib administration for pain management after total knee arthroplasty - a randomized, controlled study

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are recommended for multimodal postoperative pain management. We evaluated opioid-sparing effects and rehabilitative results after perioperative celecoxib administration for total knee arthroplasty.

METHODS

This was a prospective, randomized, observer-blind control study. Eighty patients that underwent total knee arthroplasty were randomized into two groups of 40 each. The study group received a single 400 mg dose of celecoxib, one hour before surgery, and 200 mg of celecoxib every 12 hours for five days, along with patient-controlled analgesic (PCA) morphine. The control group received only PCA morphine for postoperative pain management. Visual analog scale (VAS) pain scores, active range of motion (ROM), total opioid use and postoperative nausea/vomiting were analyzed.

RESULTS

Groups were comparable for age, pre-operative ROM, operation duration and intraoperative blood loss. Resting VAS pain scores improved significantly in the celecoxib group, compared with controls, at 48 hrs (2.13 +/- 1.68 vs. 3.43 +/- 1.50, p = 0.03) and 72 hrs (1.78 +/- 1.66 vs. 3.17 +/- 2.01, p = 0.02) after surgery. Active ROM also increased significantly in the patients that received celecoxib, especially in the first 72 hrs [40.8 degrees +/- 17.3 degrees vs. 25.8 degrees +/- 11.5 degrees , p = 0.01 (day 1); 60.7 degrees +/- 18.1 degrees vs. 45.0 degrees +/- 17.3 degrees , p = 0.004 (day 2); 77.7 degrees +/- 15.1 degrees vs. 64.3 degrees +/- 16.9 degrees , p = 0.004 (day 3)]. Opioid requirements decreased about 40% (p = 0.03) in the celecoxib group. Although patients suffering from post-operative nausea/vomiting decreased from 43% in control group to 28% in celecoxib group, this was not significant (p = 0.57). There were no differences in blood loss (intra- and postoperative) between the groups. Celecoxib resulted in no significant increase in the need for blood transfusions.

CONCLUSION

Perioperative celecoxib significantly improved postoperative resting pain scores at 48 and 72 hrs, opioid consumption, and active ROM in the first three days after total knee arthroplasty, without increasing the risks of bleeding.

TRIAL REGISTRATION

Clinicaltrials.gov NCT00598234.

Update on the role of nonsteroidal anti-inflammatory drugs and coxibs in the management of acute pain

PURPOSE OF REVIEW

Although NSAIDs have been shown to reduce postoperative analgesics, their ability to reduce opioid-related adverse effects and improve functional outcomes is questioned. Further, perioperative NSAID use may contribute to cardiovascular toxicity and impaired bone healing. This review highlights recent advances in our understanding of the role perioperative NSAIDs have on modulating nociception, their benefits when utilized as components of a multimodal analgesic regimen, and potential deleterious cardiovascular and osteogenic effects.

RECENT FINDINGS

Recent research indicates that, in addition to peripheral blockade of prostaglandin synthesis, central inhibition of cyclooxygenase-2 may play an important role in modulating nociception. Although nonspecific NSAIDs provide analgesic efficacy similar to coxibs, their use has been limited in the perioperative setting because of platelet dysfunction and gastrointestinal toxicity. Coxibs may be a safer alternative in that setting. Both coxibs and traditional NSAIDs may contribute to a dose-dependent increase in cardiovascular toxicity and impaired osteogenesis. When used short term at the lowest effective dose, however, NSAIDs may provide for analgesic benefit without significant toxicity.

SUMMARY

When utilized as a component of a multimodal analgesic regimen for acute pain, short-term NSAID administration reduces opioid-related side effects and may contribute to improved functional outcomes without significant adverse effects.

Preventive effects of perioperative parecoxib on post-discectomy pain

BACKGROUND

Cyclooxygenase inhibitor treatment is viewed increasingly critical because of safety considerations, and there are several open questions on their optimal use.

METHODS

In a randomized placebo-controlled study in 320 patients undergoing discectomy, we administered parecoxib 40 mg either perioperatively (before operation and after operation), after operation (first dose given in the evening after surgery), or before operation (single parecoxib dose given 45 min before surgery). We measured the main outcome variables: average pain score, morphine consumption, and opioid-related symptom distress at 25, 49, and 73 h after surgery.

RESULTS

Perioperative parecoxib significantly (i) improved the pain score compared with both placebo and postoperative parecoxib, (ii) decreased morphine consumption, and (iii) reduced the opioid-related symptom distress score. Neither a single preoperative dose nor postoperative parecoxib (first dose given in the evening after surgery) significantly improved morphine's analgesic effectiveness.

CONCLUSIONS

Perioperative parecoxib compared with postoperative parecoxib improves post-discectomy pain and results in a reduction in adverse effects associated with opioid therapy. Postoperative parecoxib, or a single pre-incisional parecoxib dose, does not significantly improve post-discectomy pain or opioid side-effects up to 3 days after surgery.

Efficacy and tolerability of oxymorphone immediate release for acute postoperative pain after abdominal surgery: a randomized, double-blind, active- and placebo-controlled, parallel-group trial

BACKGROUND

Patients are typically switched from parenteral opioids to oral opioids during the 24 to 48 hours after surgery. In June 2006, an oral immediate-release (IR) tablet formulation of oxymorphone was approved for the treatment of acute moderate to severe pain. Single doses of oxymorphone IR have been reported to provide significant pain relief after orthopedic surgery.

OBJECTIVE

This study assessed the efficacy and tolerability of multiple fixed doses of oxymorphone IR in the treatment of acute postoperative pain after abdominal surgery.

METHODS

This was a multicenter, randomized, double-blind, active- and placebo-controlled, parallel-group study in men and women aged >or=18 years undergoing abdominal surgery that required a >or=3-cm incision. Patients who discontinued short-acting parenteral opioids and developed moderate or severe pain (4-point categorical scale [none, mild, moderate, or severe] and pain intensity >or=50 mm on a 100-mm visual analog scale [from 0 = no pain to 100 = worst pain imaginable]) within 30 hours after abdominal surgery were randomized to receive oxymorphone IR 10 or 20 mg, oxycodone IR 15 mg, or placebo every 4 to 6 hours after the previous dose. The study included 2 efficacy assessments: a single-dose evaluation for up to 6 hours after the dose, and a multipledose evaluation for up to 48 hours after the first dose. Pain was assessed at 15-minute intervals during the hour after the first dose, hourly thereafter for the next 5 hours, and before each subsequent dose. The primary efficacy end point was the median time to study discontinuation for all causes. Assessment of tolerability was based on the proportion of study discontinuations due to treatment-emergent adverse events (AEs).

RESULTS

Three hundred thirty-one patients were included in the study. Demographic characteristics were similar across all groups: 98.8% (327) of patients were women, and 80.1% (265) of the abdominal surgeries were hysterectomies. The mean (SD) age of the study population was 42.6 (9.3) years. The median time to study discontinuation for all causes was significantly longer for all active treatments compared with placebo (oxymorphone IR 10 mg, 17.9 hours; oxymorphone IR 20 mg, 20.3 hours; oxycodone IR 15 mg, 24.1 hours; placebo, 4.8 hours; P < 0.006). Oxymorphone IR 20 mg was significantly more effective than placebo over the 6-hour single-dose evaluation (P < 0.05). With multiple dosing, all active-treatment groups had significantly lower least squares mean current and average pain intensities compared with placebo (P < 0.004 and P < 0.005, respectively). The least squares means of the average pain intensity were significantly lower among patients treated with oxymorphone IR 10 mg, oxymorphone IR 20 mg, or oxycodone IR 15 mg compared with those who received placebo (39.7, 35.2, 39.8, and 50.1, respectively; P < 0.005). Discontinuations due to treatment-emergent AEs did not differ significantly between groups: 8.5% (7/82), 17.3% (14/81), 13.3% (11/83), and 12.9% (11/85) in the oxymorphone IR 10-mg, oxymorphone IR 20-mg, oxycodone IR 15-mg, and placebo groups, respectively. The proportions of patients reporting at least 1 treatment-emergent AE were 46.3% (38/82), 51.9% (42/81), and 54.2% (45/83) in the oxymorphone IR 10-mg, oxymorphone IR 20-mg, and oxycodone IR 15-mg groups, respectively, compared with 34.1% (29/85) in the placebo group (P = NS). The fixed-dose design was a study limitation, as it did not allow titration to effect and thus did not mirror clinical practice.

CONCLUSION

In this predominantly female population undergoing abdominal surgery, oxymorphone IR given every 4 to 6 hours for up to 48 hours provided efficacious and tolerable analgesia for moderate to severe pain.

Gabapentin and postoperative pain: a qualitative and quantitative systematic review, with focus on procedure

Background

Gabapentin is an antiepileptic drug used in a variety of chronic pain conditions. Increasing numbers of randomized trials indicate that gabapentin is effective as a postoperative analgesic. This procedure-specific systematic review aims to analyse the 24-hour postoperative effect of gabapentin on acute pain in adults.

Methods

Medline, The Cochrane Library and Google Scholar were searched for double-blind randomized placebo controlled trials of gabapentin for postoperative pain relief compared with placebo, in adults undergoing a surgical procedure.

Qualitative analysis of postoperative effectiveness was evaluated by assessment of significant difference (P < 0.05) in pain relief using consumption of supplemental analgesic and pain scores between study groups.

Quantitative analyses of combined data from similar procedures, were performed by calculating the weighted mean difference (WMD) of 24-hour cumulated opioid requirements, and the WMD for visual analogue scale (VAS) pain, (early (6 h) and late (24 h) postoperatively), between study groups. Side-effects (nausea, vomiting, dizziness and sedation) were extracted for calculation of their relative risk (RR).

Results

Twenty-three trials with 1529 patients were included. In 12 of 16 studies with data on postoperative opioid requirement, the reported 24-hour opioid consumption was significantly reduced with gabapentin. Quantitative analysis of five trials in abdominal hysterectomy showed a significant reduction in morphine consumption (WMD – 13 mg, 95% confidence interval (CI) -19 to -8 mg), and in early pain scores at rest (WMD – 11 mm on the VAS, 95% CI -12 to -2 mm) and during activity (WMD -8 mm on the VAS; 95% CI -13 to -3 mm), favouring gabapentin. In spinal surgery, (4 trials), analyses demonstrated a significant reduction in morphine consumption (WMD of – 31 mg (95%CI – 53 to -10 mg) and pain scores, early (WMD – 17 mm on the VAS; 95 % CI -31 to -3 mm) and late (WMD -12 mm on the VAS; 95% CI -23 to -1 mm) also favouring gabapentin treatment. Nausea was improved with gabapentin in abdominal hysterectomy (RR 0.7; 95 % CI 0.5 to 0.9). Other side-effects were unaffected.

Conclusion

Perioperative use of gabapentin has a significant 24-hour opioid sparing effect and improves pain score for both abdominal hysterectomy and spinal surgery. Nausea may be reduced in abdominal hysterectomy.

Etoricoxib pre-medication combined with intra-operative subacromial block for pain after arthroscopic acromioplasty

BACKGROUND

Arthroscopic shoulder surgery under general anaesthesia is often associated with severe post-operative pain which may delay discharge and the start of rehabilitation. Etoricoxib is a new cyclo-oxygenase-2 inhibitor with a long duration of action and a lack of a deteriorating effect on platelet function. Therefore, the effect of pre-operative etoricoxib combined with local anaesthesia on post-operative pain and the discharge profile was studied in day-surgery patients undergoing arthroscopic shoulder surgery under general anaesthesia.

METHODS

Thirty ASA I-II adult patients scheduled for arthroscopic shoulder surgery were enrolled in this randomized prospective study. Half of the patients received etoricoxib 120 mg orally (group E) and the other half received placebo tablet orally (group C) 1 h before surgery. All patients received 20 ml of bupivacaine 2.5 mg/ml solution with epinephrine at the start of surgery and 20 ml of bupivacaine 5.0 mg/ml solution with epinephrine at the end of surgery into the subacromial space. All patients received general anaesthesia with spontaneous breathing via a laryngeal mask. In the post-anaesthesia care unit, pain was assessed on a scale from 0 to 10 (visual analogue scale, VAS) and intravenous fentanyl 25 microg was administered as scheduled (VAS > or = 3). In the day-surgery unit and at home, the analgesic was a tablet containing paracetamol 500 mg + codeine 30 mg (VAS > or = 3), as needed.

RESULTS

Patients in group E reported lower post-operative pain scores at 30, 60, 120 (P < 0.01) and 180 min (P < 0.05) after surgery, and longer time to first analgesic use (P < 0.05). Patients in group E required less fentanyl (P < 0.05) and were discharged more quickly (P < 0.05) than patients in group C. Patients in group E had a lower cumulative consumption of paracetamol + codeine tablets (P < 0.05) and lower pain scores (P < 0.05) during 7 days at home than patients in group C. Adverse events were rare in both groups.

CONCLUSION

In patients having arthroscopic shoulder surgery under general anaesthesia combined with intra-operative subacromial regional analgesia, etoricoxib 120 mg reduced immediate and late post-operative pain, and facilitated early post-operative discharge.

The addition of tramadol to morphine via patient-controlled analgesia does not lead to better post-operative pain relief after total knee arthroplasty

BACKGROUND

Tramadol is used as an analgesic in post-operative pain treatment. Intravenous tramadol is often combined with morphine to achieve better pain relief and less side-effects after orthopaedic surgery. However, the available evidence is insufficient to support this combination. For this reason, we conducted the present non-commercial, randomized, double-blind clinical trial.

METHOD

Sixty-three patients with osteoarthritis of the knee, selected for primary total knee arthroplasty (TKA), were randomized to receive saline or tramadol 100 mg/ml intravenously every 6 h during the first post-operative day (total, 400 mg/24 h). All patients had access to morphine via a patient-controlled analgesia (PCA) pump.

RESULTS

Neither during the 6 h after the first dose nor during the first post-operative day could we detect any statistically significant difference with regard to pain intensity, sedation and nausea between patients treated with tramadol and the placebo group. However, the withdrawal rate caused by insufficient pain relief was greater in the tramadol group (7/31) than in the saline group (2/32). This difference did not reach statistical significance. In the group of patients who remained in the study for 24 h ('per protocol'), those randomized to receive tramadol had a significantly (P < 0.05) lower morphine consumption (20 mg or 31%) than the placebo group.

CONCLUSION

Our study does not support the combination of tramadol and morphine via PCA for post-operative pain relief after primary TKA. In addition, our study indicates that morphine via PCA as the sole means of post-operative analgesia does not provide sufficient pain relief after TKA. Thus, other means of post-operative analgesia should be used following TKA.

Lack of analgesic effect of parecoxib following laparoscopic cholecystectomy

BACKGROUND

The cyclo-oxygenase-2 inhibitor, parecoxib, can be administered parenterally. The recommended dose for post-operative use is 40 mg twice daily, which may not be the appropriate dose for the treatment of visceral pain. We studied the effect of a single dose of parecoxib of either 40 or 80 mg in laparoscopic cholecystectomy, and its effect on opioid-induced side-effects.

METHODS

Seventy-three patients scheduled for elective laparoscopic cholecystectomy were enrolled in this prospective, randomized, double-blind study. Patients were randomized into three groups: a placebo-treated control group, a 40-mg parecoxib-treated group (P40) and an 80-mg parecoxib-treated group (P80). We recorded the cumulative fentanyl consumption during the first 20 h post-operatively by patient-controlled analgesia equipment, the pain scores during rest, coughing and mobilization (visual analogue scale, 0-10), the worst pain during the first 2 h post-operatively and in the following 18 h, and the side-effects by questionnaire.

RESULTS

No significant differences in fentanyl consumption between the three groups could be detected. The worst pain experienced between 2 and 20 h post-operatively on the ward was significantly lower in the P80 group than in the control group.

CONCLUSION

The recommended dose of parecoxib, 40 mg, is not effective for the treatment of pain during the early post-operative period after laparoscopic cholecystectomy. Doubling the dose to 80 mg seems to improve the results.

Etoricoxib pre-medication for post-operative pain after laparoscopic cholecystectomy

BACKGROUND

Etoricoxib alleviates and prevents acute pain. The hypothesis of our study was that the pre-operative use of etoricoxib would reduce the post-operative need for additional pain treatment.

METHODS

In this double-blind, randomized and active placebo-controlled study, 75 patients were pre-medicated 1.5 h before elective laparoscopic cholecystectomy with 120 mg of etoricoxib (E120 group), the same dose of etoricoxib combined with 1 g of paracetamol (E + P group) or placebo (Pla group). To alleviate post-operative pain, a patient-controlled analgesia (PCA) device was programmed to deliver 50 microg of fentanyl intravenously (lockout time, 5 min). The pain intensity and nausea were assessed using a visual analogue scale (VAS). The number of patients with post-operative nausea and vomiting was recorded. Blood loss was compared between the groups. Because the operations are almost blood-less, the operation time was also recorded to compare the possible effect on bleeding time.

RESULTS

Pre-medication with etoricoxib or etoricoxib plus paracetamol had a statistically significant fentanyl-sparing effect 2-20 h post-operatively compared with placebo (P = 0.001). No significant differences were demonstrated in fentanyl-sparing effect between the E120 and E + P groups. No significant differences in pain intensity were found between the three study groups. No significant differences were observed between the groups with regard to nausea, blood loss, duration of anaesthesia or duration of surgery.

CONCLUSION

Etoricoxib is suitable for pre-medication before laparoscopic cholecystectomy as it reduces the need for post-operative opioids. Opioid-related side-effects, however, were not reduced in the present study, despite the observed opioid-sparing effect of etoricoxib and combined etoricoxib and paracetamol.

Perioperative management of chronic pain patients with opioid dependency

PURPOSE OF REVIEW

In this article, we discuss the perioperative anesthesia and pain management of patients with chronic pain receiving chronic opioid administration. In our practice we may expect to be confronted with opioid-dependent patients in routine anesthesia practice and should acquire specific knowledge and skills to effectively manage the perioperative and acute pain management issues that arise.

RECENT FINDINGS

The number of patients treated chronically with opioids has increased steadily over the past decade; currently about 10% of all chronic-pain patients are treated with opioids. As these patients are no longer confined to terminally ill cancer patients, growing numbers of these patients are facing surgical interventions.

SUMMARY

In our clinical practice, we should employ multimodal pain management therapy by using an around-the-clock regimen of nonsteroidal anti-inflammatory drugs, cyclooxygenase-2 inhibitors, acetaminophen, and regional blockade. Dosing regimens should be individualized to optimize efficacy while minimizing the risk of adverse events.

[Critical reevaluation of cyclooxygenase two inhibitors in perioperative pain therapy]

A significant increase in thromboembolic events (i.e. myocardial infarction and stroke) was demonstrated in multicenter studies after several months of treatment with cyclooxygenase 2 (cox-2) inhibitors. In February 2005, the European medical agencies (EMEA) substantially increased the number of contraindications for all cox-2 inhibitors. They are now contraindicated for patients with coronary artery disease. Furthermore, 2 out of 6 cox-2 inhibitors have been withdrawn from the market. In this review, the current state of knowledge on the use of cox-2 inhibitors in perioperative pain therapy is summarized: i) they are equally as potent as other non-opioid analgesics, ii) they decrease opioid consumption, iii) a reduction in postoperative nausea and vomiting (PONV) has not been adequately demonstrated. Regarding side-effects, it can be concluded that i) the incidence of thromboembolic events is increased in patients undergoing coronary artery bypass surgery, ii) perioperative blood loss is not affected, iii) ulcer formation is not promoted, iv) the risk for acute renal failure is probably increased to the same extent as for NSAIDs and v) severe bronchospasm can be triggered in patients with asthma and chronic obstructive pulmonary disease (COPD).

Does perioperative administration of rofecoxib improve analgesia after spine, breast and orthopaedic surgery?

BACKGROUND AND OBJECTIVE

Data on the effectiveness of cyclooxygenase 2 inhibitors in postoperative pain therapy vary widely. We tested in a prospective, placebo-controlled, randomized, double-blind trial the hypotheses that perioperative (i.e. preoperative and postoperative) administration of the cyclooxygenase 2 inhibitor rofecoxib decreases pain scores and morphine consumption after spine, breast and orthopaedic surgery.

METHODS

Five hundred and forty patients scheduled for spine, breast or orthopaedic surgery were randomly assigned to receive in combination with postoperative morphine via patient controlled analgesia pump for 4 days either rofecoxib 50 mg administered perioperatively, rofecoxib 50 mg administered only postoperatively, or placebo. Primary outcome criteria were pain score at rest (numeric rating scale 0-4) and morphine consumption.

RESULTS

Perioperative rofecoxib significantly decreased pain score 0 (0-1) vs. 1 (0-2) (median (interquartile range)), and morphine consumption 18 (6-33) vs. 22.5 (12-38) compared with placebo. In contrast, rofecoxib when administered only postoperatively did not significantly improve analgesic effects or side-effects at time of assessment of the main criteria (24 h after skin closure), but during the follow-up period at 48 h and 72 h after skin closure pain scores and morphine consumption were improved compared to placebo. The analgesic effects of rofecoxib were independent from the type of surgery.

CONCLUSIONS

Perioperative administration of the cyclooxygenase 2 inhibitor rofecoxib decreases pain scores and morphine consumption after orthopaedic, breast and spine surgery. However, the benefit of preoperative administration of the cyclooxygenase 2 inhibitor seems to be only moderate, suggesting that early postoperative administration may be a useful alternative approach. There is no evidence that the type of surgery influences analgesic effects of cyclooxygenase 2 inhibitors.