Superior postoperative analgesic efficacy of a continuous infusion of tramadol and dipyrone (metamizol) versus tramadol alone

Postoperative pain management in children: Guidance from the pain committee of the European Society for Paediatric Anaesthesiology (ESPA Pain Management Ladder Initiative)

The main remit of the European Society for Paediatric Anaesthesiology (ESPA) Pain Committee is to improve the quality of pain management in children. The ESPA Pain Management Ladder is a clinical practice advisory based upon expert consensus to help to ensure a basic standard of perioperative pain management for all children. Further steps are suggested to improve pain management once a basic standard has been achieved. The guidance is grouped by the type of surgical procedure and layered to suggest basic, intermediate, and advanced pain management methods. The committee members are aware that there are marked differences in financial and personal resources in different institutions and countries and also considerable variations in the availability of analgesic drugs across Europe. We recommend that the guidance should be used as a framework to guide best practice.

Metamizole-associated adverse events: a systematic review and meta-analysis

Background

Metamizole is used to treat pain in many parts of the world. Information on the safety profile of metamizole is scarce; no conclusive summary of the literature exists.

Objective

To determine whether metamizole is clinically safe compared to placebo and other analgesics.

Methods

We searched CENTRAL, MEDLINE, EMBASE, CINAHL, and several clinical trial registries. We screened the reference lists of included trials and previous systematic reviews. We included randomized controlled trials that compared the effects of metamizole, administered to adults in any form and for any indication, to other analgesics or to placebo. Two authors extracted data regarding trial design and size, indications for pain medication, patient characteristics, treatment regimens, and methodological characteristics. Adverse events (AEs), serious adverse events (SAEs), and dropouts were assessed. We conducted separate meta-analyses for each metamizole comparator, using standard inverse-variance random effects meta-analysis to pool the estimates across trials, reported as risk ratios (RRs). We calculated the DerSimonian and Laird variance estimate T² to measure heterogeneity between trials. The pre-specified primary end point was any AE during the trial period.

Results

Of the 696 potentially eligible trials, 79 trials including almost 4000 patients with short-term metamizole use of less than two weeks met our inclusion criteria. Fewer AEs were reported for metamizole compared to opioids, RR = 0.79 (confidence interval 0.79 to 0.96). We found no differences between metamizole and placebo, paracetamol and NSAIDs. Only a few SAEs were reported, with no difference between metamizole and other analgesics. No agranulocytosis or deaths were reported. Our results were limited by the mediocre overall quality of the reports.

Conclusion

For short-term use in the hospital setting, metamizole seems to be a safe choice when compared to other widely used analgesics. High-quality, adequately sized trials assessing the intermediate- and long-term safety of metamizole are needed.

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

BACKGROUND

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

NON-OPIOIDS

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

OPIOIDS

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

KETAMINE

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

Effect of combining tramadol and morphine in adult surgical patients: a systematic review and meta-analysis of randomized trials

The role for tramadol in multimodal postsurgical analgesic strategies remains unclear. We undertook a systematic review to evaluate the utility of combining tramadol with morphine after surgery. We searched the MEDLINE, EMBASE, LILAC, Cochrane, and Clinical Trial Register databases for randomized, controlled studies comparing tramadol with placebo or active control in patients undergoing surgery. Fourteen studies (713 patients) were included. There was a limited but significant postoperative morphine-sparing effect, with a weighted mean difference (WMD) of -6.9 (95% confidence interval -11.3 to -2.5) mg. This effect was not associated with a decrease in morphine-related adverse effects. No difference in the incidence of nausea, vomiting, sedation, or shivering was observed. There was no decrease in pain intensity at 24 h; the WMD was -0.9 (-7.2; 5.2) on a 100 mm visual analogue scale at 24 h. We found no significant clinical benefit from the combination of i.v. tramadol and morphine after surgery.

Estimation of the minimum effective dose of tramadol for postoperative analgesia in infants using the continual reassessment method

Tramadol is a potent analgesic. However, the analgesia efficacy of tramadol, particularly its minimum effective dose (MED), is not clear. The aim of this study is to find MED of tramadol for postoperative analgesia in infants. The continual reassessment method (CRM) was performed to find MED. Infants undergoing surgeries were included in the 3 phases of this series. In each phase, 24 participants were allocated a different tramadol dose. Pain intensity was measured by face, legs, activity, cry, consolability (FLACC) measurement at 3-hour intervals. Tramadol was considered ineffective if the FLACC score was higher than 4 in 10 at anytime. In phase 1, seven dose levels were used within the range 0.1-0.4 mg·kg(-1)·h(-1). Phase 1 was insufficient to identify the MED, and we increased the dose to 0.4-0.8 mg·kg(-1)·h(-1) in phase 2. Phase 2 was insufficient to identify the MED. In phase 3, local anesthetic wound infiltration was introduced, and the tramadol dose levels tested were the same as in phase 1. The successful analgesia probability of tramadol 0.4 mg·kg(-1)·h(-1) was 82.1% (95% CI, 0.742-0.925) in phase 1. In phase 2, it was 84.7% (95% CI, 0.789-0.991) with the dose 0.8 mg·kg(-1)·h(-1). Phase 1 and phase 2 were insufficient to identify the MED. In phase 3, the successful analgesia probability for dose 0.35 mg·kg(-1)·h(-1) was 96.7% (95% CI, 0.853-0.997).We have demonstrated that tramadol provides insufficient analgesia for surgeries considered to cause moderate-to-severe postoperative pain in infants if used as the sole analgesic, and that local anesthetic wound infiltration enhances the efficacy of tramadol.

Implementation of a standardized pain management in a pediatric surgery unit

Postoperative pain is still a major complication causing discomfort and significant suffering, especially for children. Therefore, every effort should be made to prevent pain and treat it effectively once it arises. Under-treatment of pediatric pain is often due to a lack of both knowledge about age-specific aspects of physiology and pharmacology and routine pain assessment. Factors for long term success require regularly assessing pain, as routinely as the other vital signs together with documentation of side effects. The fear of side effects mostly prevents the adequate usage of analgesics. Essential is selecting and establishing a simple concept for clinical routine involving a combination of non-pharmacological treatment strategies, non-opioid drugs, opioids and regional anesthesia.

[Drugs for postoperative analgesia: routine and new aspects: Part 2: opioids, ketamine and gabapentinoids]

In part 1 of this review, perioperative aspects of the use of non-opioids (acetaminophene, dipyrone, traditional NSAR, coxibs) were discussed. In part 2 the perioperative aspects of opioids (weak opioids: tramadol, tilidine with naloxone, strong opioids: morphine, piritramide, oxycodone, hydromorphone, fentanyl, methadone, buprenorphine) and coanalgesics (gabapentinoids; ketamine) will now be presented. The main aim of the review is to describe the use, risks and cost of some substances to facilitate the differential indication. New aspects concerning the use of gabapentinoids and ketamine are discussed.

Analgetikakombinationen zur postoperativen Schmerztherapie

BACKGROUND

The supplementation of an opioid by a non-opioid analgesic is a widely accepted technique for the treatment of postoperative pain. However, it is still unclear whether a combination of different non-opioids has an advantage in terms of an improved analgesia and/or a reduction of the opioid-related adverse effects.

METHODOLOGY

A systematic analysis of the literature was performed searching for randomized, controlled trials studying the effects of a combination of two non-opioid analgesics in order to reduce postoperative opioid requirements and/or postoperative pain. Significant reduction of the postoperative opioid requirement and/or postoperative pain were defined as main rating criteria. To facilitate comparisons between the trials, the relative (proportional) reduction of postoperative opioid administration and the relative reduction of postoperative pain were calculated on defined pain scales.

RESULTS

A total of 25 trials were identified, mainly studies comparing non-steroidal anti-inflammatory drugs (NSAIDs) with paracetamol. Only 3 trials found a statistically improved analgesic efficacy and 15 studies did not show any relevant improvement or the combination group was only significantly superior to one of the groups receiving monotherapy. A further seven studies could not be evaluated due to methodological issues. There was no evidence for a significant reduction of opioid-induced adverse effects.

CONCLUSION

A combination of non-opioid analgesics, in particular NSAIDs with paracetamol, cannot be recommended at present due to the lack of data showing improved effectiveness.

Modern concepts of acute and chronic pain management

Both, acute and chronic pain should be treated using appropriate pain management as they may cause several negative reactions and jeopardise the health or at least the quality of life of the patients. Nowadays there are many analgesics and treatment tools available to provide sufficient pain relief for almost all patients. Unfortunately there are still patients suffering from pain due to inadequate or/and inconsequent pain therapy.

Anästhesie und Analgesie bei Suchtpatienten

Addicts have an exaggerated organic and psychological comorbidity and in cases of major operations or polytrauma they are classified as high-risk patients. Additional perioperative problems are a higher analgetics requirement, craving, physical and/or psychological withdrawal symptoms, hyperalgesia and tolerance. However, the clinical expression depends on the substance abused. For a better understanding of the necessary perioperative measures, it is helpful to classify the substances into central nervous system depressors (e.g. heroin, alcohol, sedatives, hypnotics), stimulants (e.g. cocaine, amphetamines, designer drugs) and other psychotropic substances (e.g. cannabis, hallucinogens, inhalants). The perioperative therapy should not be a therapy for the addiction, as this is senseless. On the contrary, the characteristics of this chronic disease must be accepted. Anesthesia and analgesia must be generously stress protective and sufficiently analgesically effective. Equally important perioperative treatment principles are stabilization of physical dependence by substitution with methadone (for heroin addicts) or benzodiazepines/clonidine (for alcohol, sedatives and hypnotics addiction), avoidance of stress and craving, thorough intraoperative and postoperative stress relief by using regional techniques or systematically higher than normal dosages of anesthetics and opioids, strict avoidance of inadequate dosage of analgetics, postoperative optimization of regional or systemic analgesia by non-opioids and coanalgetics and consideration of the complex physical and psychological characteristics and comorbidities. Even in cases of abstinence (clean) an inadequate dosage must be avoided as this, and not an adequate pain therapy sometimes even with strong opioids, can potentially activate addiction. A protracted abstinence syndrome after withdrawal of opioids can lead to increased response to administered opioids (e.g. analgesia, side-effects).