Improved postoperative pain control in pediatric adenotonsillectomy with dextromethorphan

A scoping review of randomized clinical trials for pain management in pediatric tonsillectomy and adenotonsillectomy

Objectives

To examine the volume, topics, and reporting trends in the published literature of randomized clinical trials for pharmacologic pain management of pediatric tonsillectomy and adenotonsillectomy and to identify areas requiring further research.

Data Sources

PubMed (National Library of Medicine and National Institutes of Health), Scopus (Elsevier), CINAHL (EBSCO), and Cochrane Library (Wiley).

Methods

A systematic search of four databases was conducted. Only randomized controlled or comparison trials examining pain improvement with a pharmacologic intervention in pediatric tonsillectomy or adenotonsillectomy were included. Data collected included demographics, pain-related outcomes, sedation scores, nausea/vomiting, postoperative bleeding, types of drug comparisons, modes of administration, timing of administration, and identities of the investigated drugs.

Results

One hundred and eighty-nine studies were included for analysis. Most studies included validated pain scales, with the majority using visual-assisted scales (49.21%). Fewer studies examined pain beyond 24 h postoperation (24.87%), and few studies included a validated sedation scale (12.17%). Studies have compared several different dimensions of pharmacologic treatment, including different drugs, timing of administration, modes of administration, and dosages. Only 23 (12.17%) studies examined medications administered postoperatively, and only 29 (15.34%) studies examined oral medications. Acetaminophen only had four self-comparisons.

Conclusion

Our work provides the first scoping review of pain and pediatric tonsillectomy. With drug safety profiles considered, the literature does not have enough data to determine which treatment regimen provides superior pain control in pediatric tonsillectomy. Even common drugs like acetaminophen and ibuprofen require further research for optimizing the treatment of posttonsillectomy pain. The heterogeneity in study design and comparisons weakens the conclusions of potential systematic reviews and meta-analyses. Future directions include more noninferiority studies of unique comparisons and more studies examining oral medications given postoperatively.

Guidelines for Opioid Prescribing in Children and Adolescents After Surgery: An Expert Panel Opinion

IMPORTANCE

Opioids are frequently prescribed to children and adolescents after surgery. Prescription opioid misuse is associated with high-risk behavior in youth. Evidence-based guidelines for opioid prescribing practices in children are lacking.

OBJECTIVE

To assemble a multidisciplinary team of health care experts and leaders in opioid stewardship, review current literature regarding opioid use and risks unique to pediatric populations, and develop a broad framework for evidence-based opioid prescribing guidelines for children who require surgery.

EVIDENCE REVIEW

Reviews of relevant literature were performed including all English-language articles published from January 1, 1988, to February 28, 2019, found via searches of the PubMed (MEDLINE), CINAHL, Embase, and Cochrane databases. Pediatric was defined as children younger than 18 years. Animal and experimental studies, case reports, review articles, and editorials were excluded. Selected articles were graded using tools from the Oxford Centre for Evidence-based Medicine 2011 levels of evidence. The Appraisal of Guidelines for Research & Evaluation (AGREE) II instrument was applied throughout guideline creation. Consensus was determined using a modified Delphi technique.

FINDINGS

Overall, 14 574 articles were screened for inclusion, with 217 unique articles included for qualitative synthesis. Twenty guideline statements were generated from a 2-day in-person meeting and subsequently reviewed, edited, and endorsed externally by pediatric surgical specialists, the American Pediatric Surgery Association Board of Governors, the American Academy of Pediatrics Section on Surgery Executive Committee, and the American College of Surgeons Board of Regents. Review of the literature and guideline statements underscored 3 primary themes: (1) health care professionals caring for children who require surgery must recognize the risks of opioid misuse associated with prescription opioids, (2) nonopioid analgesic use should be optimized in the perioperative period, and (3) patient and family education regarding perioperative pain management and safe opioid use practices must occur both before and after surgery.

CONCLUSIONS AND RELEVANCE

These are the first opioid-prescribing guidelines to address the unique needs of children who require surgery. Health care professionals caring for children and adolescents in the perioperative period should optimize pain management and minimize risks associated with opioid use by engaging patients and families in opioid stewardship efforts.

Opioid-Sparing Anesthetic Technique for Pediatric Patients Undergoing Adenoidectomy: A Pilot Study

INTRODUCTION

An opioid-sparing anesthetic involves a multi-modal technique with non-opioid medications targeting different analgesic pathways. Such techniques may decrease adverse effects related to opioids. These techniques may be considered in patients at higher risk for opioid-related adverse effects including obstructive sleep apnea or sleep disordered breathing.

METHODS

A prospective, pilot study was performed in 10 patients (3-8 years of age), presenting for adenoidectomy. The perioperative regimen included oral dextromethorphan (1 mg/kg) and acetaminophen (15 mg/kg) plus single boluses of intraoperative dexmedetomidine (0.5 μg/kg) and ketamine (0.5 mg/kg). Pain scores were assessed in the post anesthesia care unit (PACU) using the FLACC (Face, Legs, Activity, Cry, Consolability) scale. Patients with a pain score >4 received fentanyl as needed. PACU time, pain scores, and parent satisfaction were recorded. Postoperatively, patients were instructed to use oral acetaminophen or ibuprofen every 6 hours as needed for pain.

RESULTS

The study cohort included 10 patients, 3-8 years of age. All patients had opioid-free anesthetic care. PACU time ranged from 24 to 102 minutes (median: 56 minutes). FLACC pain scores were 0 for all PACU assessments. Nine patients were discharged home and 1 patient had a planned overnight admission. Following hospital discharge, the pain scores were satisfactory during the 72-hour study period and 90% of the patients' guardians were satisfied or highly satisfied with their child's pain control.

CONCLUSION

This opioid-sparing approach provided safe and effective pain control as well as parental satisfaction following adenoidectomy in children. Additional prospective studies are needed to determine whether this regimen is effective in a larger cohort of patients with and for other otolaryngology procedures.

Medication Repurposing in Pediatric Patients: Teaching Old Drugs New Tricks

OBJECTIVES

Gaps in pediatric therapeutics often result in off-label use and specifically, novel uses for existing medications, termed "drug repurposing." Drug Information (DI) queries to a Pediatric Medication Resource Center of a large metropolitan pediatric hospital in New York and inherent difficulties in retrieving evidence-based information prompted a review of current medication repurposing for pediatric patients. The objective included characterization of innovative off-label use of medications Food and Drug Administration (FDA)-approved for 1 or more indications to treat a totally different disorder or indication in pediatric patients.

METHODS

A systematic literature review was conducted to retrieve publications describing repurposed medications in pediatric patients. Excluded was FDA-approved indications used off-label in pediatric patients (e.g., different dose), preclinical data, adult use only, and experimental use. Evidence quality was classified using a modified American Academy of Neurology Level of Evidence. Results were analyzed using χ(2) at p < 0.05.

RESULTS

Over 2000 references were retrieved and reviewed. A total of 101 medications repurposed for novel off-label uses for pediatric patients were identified: 38 for neonates, 74 for children, and 52 for adolescents. Neonates and infants were least likely to receive a medication for a repurposed use. Strong or intermediate evidence existed in 80.2% of cases. The evidence was weak in 19.8%. No significant relationship was observed between the pediatric age group and strength of the literature. Most repurposed uses pertained to generic or widely used medications. Less than 5% of medications were first marketed after 2011.

CONCLUSIONS

While not exhaustive, the present study represents the most comprehensive listing of novel uses exclusive to pediatric patients. Further research is needed to identify the frequency of repurposed uses. The valuable DI role of pharmacists in assessing repurposed uses is of expanding and increasing importance to ensure such uses are evidence-based.

Immediate rescue designs in pediatric analgesic trials: a systematic review and meta-analysis

BACKGROUND

Designing analgesic clinical trials in pediatrics requires a balance between scientific, ethical, and practical concerns. A previous consensus group recommended immediate rescue designs using opioid sparing as a surrogate measure of analgesic efficacy. The authors summarize the performance of rescue analgesic designs in pediatric trials of four commonly used classes of analgesics: opioids, nonsteroidal antiinflammatory drugs, acetaminophen, and local anesthetics.

METHODS

MEDLINE, Embase, CINAHL, The Cochrane Library, and Web of science were searched in April 2013. The 85 studies selected were randomized or controlled clinical trials using immediate rescue paradigms in postoperative pain settings. A random-effects meta-analysis was used to synthesize predefined outcomes using Hedges' g. Difference between the means of the treatment arms were also expressed as a percentage of the corresponding value in the placebo group (placebo-treatment/placebo). Distributions of pain scores in study and control groups and relationships between opioid sparing and pain scores were examined.

RESULTS

For each of the four study drug classes, significant opioid sparing was demonstrated in a majority of studies by one or more of the following endpoints: (1) total dose (milligram per kilogram per hour), (2) percentage of children requiring rescue medication, and (3) time to first rescue medication (minutes). Pain scores averaged 2.4/10 in study groups, 3.4/10 in control groups.

CONCLUSIONS

Opioid sparing is a feasible pragmatic endpoint for pediatric pain analgesic trials. This review serves to guide future research in pediatric analgesia trials, which could test whether some specific design features may improve assay sensitivity while minimizing the risk of unrelieved pain.

Acute pain management in children

The greatest advance in pediatric pain medicine is the recognition that untreated pain is a significant cause of morbidity and even mortality after surgical trauma. Accurate assessment of pain in different age groups and the effective treatment of postoperative pain is constantly being refined; with newer drugs being used alone or in combination with other drugs continues to be explored. Several advances in developmental neurobiology and pharmacology, knowledge of new analgesics and newer applications of old analgesics in the last two decades have helped the pediatric anesthesiologist in managing pain in children more efficiently. The latter include administering opioids via the skin and nasal mucosa and their addition into the neuraxial local anesthetics. Systemic opioids, nonsteroidal anti-inflammatory agents and regional analgesics alone or combined with additives are currently used to provide effective postoperative analgesia. These modalities are best utilized when combined as a multimodal approach to treat acute pain in the perioperative setting. The development of receptor specific drugs that can produce pain relief without the untoward side effects of respiratory depression will hasten the recovery and discharge of children after surgery. This review focuses on the overview of acute pain management in children, with an emphasis on pharmacological and regional anesthesia in achieving this goal.

Pharmacologic management of acute pediatric pain

The accurate assessment and effective treatment of acute pain in children in the hospital setting is a high priority. During the past 2 to 3 decades, pediatric pain management has gained tremendous knowledge with respect to the understanding of developmental neurobiology, developmental pharmacology the use of analgesics in children, the use of regional techniques in children, and of the psychological needs of children in pain. A wide range of medications is available to treat a variety of pain types. This article provides an overview of the most common analgesic medications and techniques used to treat acute pain in children.

Tramadol for pain relief in children undergoing adenotonsillectomy: a comparison with dextromethorphan

OBJECTIVE/HYPOTHESIS

Establishment of good analgesia is of major concern in the postoperative period after adenotonsillectomy. The aim of this study was to compare the effects of dextromethorphan and tramadol on postoperative pain after adenotonsillectomy in children.

STUDY DESIGN

Randomized study.

METHODS

Ninety ASA class I, II (children age, 4-10 years) scheduled for adenotonsillectomy were randomized into three groups to receive placebo syrup (control group), 1 mg/kg dose of dextromethorphan cough syrup oral (Dex group) or oral placebo syrup (Tramadol group), 30 minutes before arrival in the operating room. Then during induction of anesthesia group control received 0.9% physiological saline, group Dex received 0.9% physiological saline, group Tramadol (1 mg/kg) of tramadol hydrochloride intravenously, in a total volume of 4 mL. Postoperative analgesic requirements and side effects were recorded. Pain was assessed by face scale every hour up to 6 hours postop.

RESULTS

There were no statistically significant differences in age, weight, and sex between groups (P > .05). There were statistically significant differences in, pain scores in first time postoperatively and further analgesic requirements (P < .05). All patients in placebo group (100%), two patients in the tramadol group (6.6%), and nine patients in dextromethorphan group (40%) required supplementary meperidine in recovery room. The incidence of nausea and vomiting was 5.5% in the Dextromethorphan group, 10% in the tramadol group, 6.6% in the control group; there was no significant difference between the groups (P > .05).

CONCLUSIONS

Intravenous tramadol (1 mg/kg) is more suitable than 1 mg/kg dose of dextromethorphan cough syrup oral in reducing posttonsillectomy pain in children.

A qualitative systematic review of peri-operative dextromethorphan in post-operative pain

BACKGROUND

The N-methyl-D-aspartate (NMDA) receptor antagonist, dextromethorphan (DM), has received interest as an adjunctive agent in post-operative pain management. Clinical trials have been contradictory. This systematic review aims to evaluate the available literature examining the analgesic efficacy of DM in post-operative patients.

METHODS

Twenty-eight randomized, double-blind, clinical studies, with 40 comparisons, including a variety of dosing regimens comparing DM treatment with placebo, were included. Meta-analysis was intended but deemed to be inappropriate because of the substantial difference in methodology and reporting between trials. The outcome measures (pain scores at rest, time to first analgesic request and supplemental analgesic consumption) were evaluated qualitatively by significant difference (P<0.05) as reported in the original investigations.

RESULTS

DM did not reduce the post-operative pain score with a clinically significant magnitude. The time to first analgesic request was significantly prolonged in most comparisons with DM. Significant decreases in supplemental opioid consumption were observed in the majority of parenteral DM studies and in about one-half of the oral studies. The decreases were of questionable clinical importance in most comparisons, although a relationship between a decrease in opioid consumption and opioid-related side-effects was established in some studies.

CONCLUSION

Based on the studies available, DM has the potential to be a safe adjunctive agent to opioid analgesia in post-operative pain management, but the consistency of the potential opioid-sparing and pain-reducing effect must be questioned. Consequently, it is not possible to recommend dose regimens or routine clinical use of DM in post-operative pain. The route of administration may be important for the beneficial effect.

Intravenous dextromethorphan to human volunteers: relationship between pharmacokinetics and anti-hyperalgesic effect

The aim of this study was to investigate the effect of dextromethorphan (DM) 0.5 mg/kg administered intravenously (i.v.) on hyperalgesia and pain after a tissue injury in human volunteers, and to describe the relationship between pharmacokinetic and pharmacodynamic data. The heat-capsaicin sensitisation model, a well-established experimental hyperalgesia model was induced in 24 healthy, male volunteers aged 21-35 years. The subjects received i.v. DM 0.5 mg/kg or isotonic saline on two separate study sessions. The primary outcome measure from 0 to 3 h was reduction in area of established secondary hyperalgesia. Secondary outcome measures were reduction in area of secondary hyperalgesia in response to brief thermal stimulation, heat pain detection thresholds and painfulness after tonic heat pain. Blood samples were collected throughout the study to describe the relationship between pharmacokinetic and pharmacodynamic data. Intravenous DM 0.5 mg/kg significantly reduced areas of established secondary hyperalgesia with an average of 39% (P<0.05). Development of secondary hyperalgesia was substantially prevented by DM (P<0.05). No significant effect was seen on either heat pain detection thresholds or after tonic heat pain. The pharmacokinetic-pharmacodynamic relationship showed a large inter-subject variation with a mean delay in effect of nearly 2 h in relation to peak serum concentration. The results strongly indicate that DM is an anti-hyperalgesic drug. The delay in effect may be explained by several mechanisms and suggests that timing of DM administration is an essential factor for using the drug in clinical settings.

Postoperative pain management in children

There is increased awareness of the need for effective postoperative analgesia in infants and young children. A multi-modal approach to preventing and treating pain usually is used. Mild analgesics, local and regional analgesia, and opioids when indicated, frequently are combined to minimize adverse effects of individual drugs or techniques.

Oral dextromethorphan reduces perioperative analgesic administration in children undergoing tympanomastoid surgery

OBJECTIVE

To determine whether oral dextromethorphan (1 mg/kg) given one hour prior to surgery decreases opioid administration in the perioperative period in children undergoing tympanomastoid surgery.

METHODS

This was a prospective randomized double-blinded and placebo-controlled study in which 20 male and 18 female children (age 11.5 +/- 3.5 years) were enrolled. Nineteen children received dextromethorphan (DM), while the other 19 received placebos. Postoperative pain was assessed using a visual analogue scale and a pain score of > or =5 was treated with intravenous morphine sulfate. Patients were discharged home on oral oxycodone.

RESULTS

The total doses of fentanyl administered during surgery were higher in the placebo group compared to the DM group (4.1 +/- 2 vs 2.6 +/- 1.4 microg/kg, P = 0.02) and the total doses of intravenous morphine administered in the postoperative period were also higher in the placebo group compared to the DM group (150 +/- 80 vs 73 +/- 56 microg/kg, P = 0.004). The placebo group had a higher pain score at the time of admission to the Day Surgery Unit (DSU) and a higher maximum pain score, compared to the DM group, during their combined stay in the Post-Anesthesia Care Unit and DSU (7.3 +/- 1.5 vs 3.1 +/- 2.6, P = 0.001).

CONCLUSIONS

Premedication with DM reduces the need for opioid administration in the perioperative period in children undergoing tympanomastoid surgery.

EBM RATING

A.

The intravenous ketamine test: a predictive response tool for oral dextromethorphan treatment in neuropathic pain

IV infusion tests performed to predict subsequent response to oral analgesics are an increasingly popular method used to enhance medical care and conserve resources. Because no infusion test is completely accurate, the potential benefits of these tests must be weighed against the frustration and waste in resources encountered with false-positive results, and the failure to use a potentially beneficial treatment with false-negative results. In recent years, drugs that act antagonistically at N-methyl-d-aspartate receptors have been shown to be valuable adjuncts in the treatment of pain. To determine the predictive value of small-dose (0.1 mg/kg) IV ketamine on an oral dextromethorphan (DX) treatment regimen, we analyzed the analgesic response to these drugs in 25 patients at 2 tertiary care military treatment facilities, institutions at which DX is not readily accessible. When >/=50% response for both drugs was used as the outcome measure for success, the positive predictive value of the ketamine test was 64%, the negative predictive value 73%, and the observed agreement 68%. However, when >/=67% relief with ketamine was used as an outcome measure (as determined by a receiver operating characteristic curve), the positive predictive value was 90%, the negative predictive value 80%, and the observed agreement increased to 84%. Based on these results, we conclude that an IV ketamine test may be useful in predicting response to oral DX. More research is needed to determine the ideal candidates for such a test, and the optimal dose and cutoff value for the response to ketamine.

A Qualitative Systematic Review of the Role of N-Methyl-d-Aspartate Receptor Antagonists in Preventive Analgesia

We evaluated in a qualitative systematic review the effect of N-methyl-D-aspartate (NMDA) receptor antagonists on reducing postoperative pain and analgesic consumption beyond the clinical duration of action of the target drug (preventive analgesia). Randomized trials examining the use of an NMDA antagonist in the perioperative period were sought by using a MEDLINE (1966-2003) and EMBASE (1985-2003) search. Reference sections of relevant articles were reviewed, and additional articles were obtained if they evaluated postoperative analgesia after the administration of NMDA antagonists. The primary outcome was a reduction in pain, analgesic consumption, or both in a time period beyond five half-lives of the drug under examination. Secondary outcomes included time to first analgesic request and adverse effects. Forty articles met the inclusion criteria (24 ketamine, 12 dextromethorphan, and 4 magnesium). The evidence in favor of preventive analgesia was strongest in the case of dextromethorphan and ketamine, with 67% and 58%, respectively, of studies demonstrating a reduction in pain, analgesic consumption, or both beyond the clinical duration of action of the drug concerned. None of the four studies examining magnesium demonstrated preventive analgesia.

IMPLICATIONS

We evaluated, in a qualitative systematic review, the effect of N-methyl D-aspartate antagonists on reducing postoperative pain and analgesic consumption beyond the clinical duration of action of the target drug (preventive analgesia). Dextromethorphan and ketamine were found to have significant immediate and preventive analgesic benefit in 67% and 58% of studies, respectively.

Pain management for pediatric ambulatory anesthesia

PURPOSE OF REVIEW

New developments in analgesic drugs and techniques are being applied to the pediatric population. Appropriate pain management for ambulatory surgery patients helps to facilitate early discharge and minimize postoperative morbidity.

RECENT FINDINGS

A variety of opioid-related drugs, as well as novel delivery routes for opioids, have been reported in the pediatric population. New pharmacokinetic information for acetaminophen has resulted in revised dosage recommendations; applications of the nonsteroidal antiinflammatory agents are also discussed. Furthermore, regional anesthesia and adjuncts are useful in the pediatric ambulatory surgery patient.

SUMMARY

Recent data on techniques for pain management after pediatric ambulatory surgery will help the anesthetist develop a comprehensive plan for the postoperative period.