Age-stratified pharmacokinetics of ketorolac tromethamine in pediatric surgical patients

Impact of Ketorolac on Reoperation for Hemorrhage After Pediatric Tonsillectomy: A Single-Center Retrospective Propensity-Matched Study

OBJECTIVE

To determine if perioperative ketorolac is associated with an increased rate of reoperation for hemorrhage after pediatric tonsillectomy at 30 days and 48 hours.

STUDY DESIGN

Single-center retrospective propensity-matched study.

SETTING

Quaternary pediatric hospital and ambulatory surgery center.

METHODS

Patients less than 18 years old undergoing tonsillectomy or adenotonsillectomy between January 1, 2015 and October 1, 2020 were included. Hemorrhage rates between exposed (K+) and unexposed (K-) patients were calculated for the total cohort and a 1:1 propensity-matched cohort. Additional analyses included: multivariable logistic regression, subgroup analysis of ASA 1 and 2 patients, subgroup analysis comparing children with teenagers.

RESULTS

There were 5873 patients (42.1% K+) in the full cohort and 4694 patients in the propensity-matched cohort. Reoperation for hemorrhage within 30 days occurred in 1.9% of K+ patients and 1.6% of K- patients (P = 0.455) in the full cohort and 1.9% of K+ patients and 1.7% of K- patients (odds ratio [OR] 1.10, 95% confidence interval [CI] 0.72-1.69, P = 0.662) in the propensity-matched cohort. Reoperation within 48 hours occurred in 0.65% of K+ patients and 0.53% of K- patients (P = 0.679) in the full cohort and 0.68% of K+ patients and 0.51% of K- patients (OR 1.33, 95% CI 0.63-2.81, P = 0.451) in the propensity-matched cohort. There was no association between perioperative ketorolac administration and reoperation for hemorrhage in any of the other analyses.

CONCLUSION

Ketorolac at end of surgery should be considered as part of the nonopioid analgesic regimen for pediatric tonsillectomy.

Efficacy and Safety of Intravenous Ketorolac versus Nalbuphine in Relieving Postoperative Pain after Tonsillectomy in Children

BACKGROUND

Pain is a major postoperative complication worldwide, which in turn impairs normal body performance and increases postoperative morbidity, hospitalisation, and the susceptibility to infections which also lead to chronic pain development.

AIM

The purpose of this study was to evaluate the efficacy of intravenous ketorolac versus nalbuphine as analgesia after adenotonsillectomy surgery to determine the optimal procedure for pain control and postoperative reduction of analgesic use.

METHODS

A group of 100 pediatric patients undergoing tonsillectomy or adenotonsillectomy were assigned as follows to two equal groups: Group A: 50 patients received intravenous ketorolac 0.9 mg/Kg. Group B: 50 patients received intravenous nalbuphine 0.25 mg/Kg.

RESULTS

FLACC (Face, Legs, Activity, Cry, Consolability) pain score was measured after recovery from anaesthesia (postoperative). There was a statistically significant difference concerning pain score between group 'A' and group 'B' as pain score in 'A' (ranging from 3.18 ± 0.87 to 4.68 ± 0.74) is lower compared to 'B' (ranging from 3.90 ± 0.76 to 5.54 ± 0.73) and probability value < 0.05 except at 90 & 120 min which was observed statistically insignificant. There was no serious postoperative complication detected in either group.

CONCLUSION

It is concluded that intravenous ketorolac is more effective than intravenous nalbuphine in reducing pain intensity and postoperative analgesic requirements after adenotonsillectomy in children.

Ketorolac for postoperative pain in children

BACKGROUND

Children who undergo surgical procedures in ambulatory and inpatient settings are at risk of experiencing acute pain. Nonsteroidal anti-inflammatory drugs (NSAIDs) can reduce moderate to severe pain without many of the side effects associated with opioids. However, NSAIDs may cause bleeding, renal and gastrointestinal toxicity, and potentially delay wound and bone healing. Intravenous administration of ketorolac for postoperative pain in children has not been approved in many countries, but is routinely administered in clinical practise.

OBJECTIVES

To assess the efficacy and safety of ketorolac for postoperative pain in children.

SEARCH METHODS

We searched the following databases, without language restrictions, to November 2017: CENTRAL (The Cochrane Library 2017, Issue 10); MEDLINE, Embase, and LILACS. We also checked clinical trials registers and reference lists of reviews, and retrieved articles for additional studies.

SELECTION CRITERIA

We included randomised controlled trials that compared the analgesic efficacy of ketorolac (in any dose, administered via any route) with placebo or another active treatment, in treating postoperative pain in participants zero to 18 years of age following any type of surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently considered trials for inclusion in the review, assessed risk of bias, and extracted data. We analyzed trials in two groups; ketorolac versus placebo, and ketorolac versus opioid. However, we performed limited pooled analyses. We assessed the overall quality of the evidence for each outcome using GRADE, and created a 'Summary of findings' table.

MAIN RESULTS

We included 13 studies, involving 920 randomised participants. There was considerable heterogeneity among study designs, including the comparator arms (placebo, opioid, another NSAID, or a different regimen of ketorolac), dosing regimens (routes and timing of administration, single versus multiple dose), outcome assessment methods, and types of surgery. Mean study population ages ranged from 356 days to 13.9 years. The majority of studies chose a dose of either 0.5 mg/kg (as a single or multiple dose regimen) or 1 mg/kg (single dose with 0.5 mg/kg for any subsequent doses). One study administered interventions intraoperatively; the remainder administered interventions postoperatively, often after the participant reported moderate to severe pain.There were insufficient data to perform meta-analysis for either of our primary outcomes: participants with at least 50% pain relief; or mean postoperative pain intensity. Four studies individually reported statistically significant reductions in pain intensity when comparing ketorolac with placebo, but the studies were small and had various risks of bias, primarily due to incomplete outcome data and small sample sizes.We found limited data available for the secondary outcomes of participants requiring rescue medication and opioid consumption. For the former, we saw no clear difference between ketorolac and placebo; 74 of 135 (55%) participants receiving ketorolac required rescue analgesia in the post-anaesthesia care unit (PACU) versus 81 of 127 (64%) receiving placebo (relative risk (RR) 0.85, 95% confidence interval (CI) 0.71 to 1.00, P = 0.05; 4 studies, 262 participants). For opioid consumption in the PACU, we saw no clear difference between ketorolac and placebo (P = 0.61). For the time period zero to four hours after administration of the interventions, participants receiving ketorolac received 1.58 mg less intravenous morphine equivalents than those receiving placebo (95% CI -2.58 mg to -0.57 mg, P = 0.002; 2 studies, 129 participants). However, we are uncertain whether ketorolac has an important effect on opioid consumption, as the data were sparse and the results were inconsistent. Only one study reported data for opioid consumption when comparing ketorolac with an opioid. There were no clear differences between the ketorolac and opioid group at any time point. There were no data assessing this outcome for the comparison of ketorolac with another NSAID.There were insufficient data to allow us to analyze overall adverse event or serious adverse event rates. Although the majority of serious adverse events reported in those receiving ketorolac involved bleeding, the number of events was too low to conclude that bleeding risk was increased in those receiving ketorolac perioperatively. There was not a statistically significant increase in event rates for any specific adverse event, either in pooled analysis or in single studies, when comparing ketorolac and placebo. When comparing ketorolac with opioids or other NSAIDs, there were too few data to make any conclusions regarding event rates. Lastly, withdrawals due to adverse events were vary rare in all groups, reflecting the acute nature of such studies.We assessed the quality of evidence for all outcomes for each comparison (placebo or active) as very low, due to issues with risk of bias in individual studies, imprecision, heterogeneity between studies, and low overall numbers of participants and events.

AUTHORS' CONCLUSIONS

Due to the lack of data for our primary outcomes, and the very low-quality evidence for secondary outcomes, the efficacy and safety of ketorolac in treating postoperative pain in children were both uncertain. The evidence was insufficient to support or reject its use.

Ketorolac tromethamine: stereo-specific pharmacokinetics and single-dose use in postoperative infants aged 2-6 months

OBJECTIVE

We determined the postoperative pharmacokinetics (PK), safety, and analgesic effects of ketorolac in 14 infants (aged <6 months) receiving a single intravenous (IV) administration of racemic ketorolac or placebo.

BACKGROUND

Information on the PK of ketorolac in infants is limited. Unblinded studies suggest ketorolac may be useful in infants.

METHODS

This double-blinded, placebo-controlled study enrolled 14 infants (aged <6 months) postoperatively. At 6-18 h after surgery, infants were randomized to receive placebo, 0.5 mg·kg(-1), or 1 mg·kg(-1) ketorolac IV. All infants received morphine sulfate as needed for pain control. Blood was collected up to 12-h postdosing. Analysis used noncompartmental and compartmental population modeling methods.

RESULTS

In addition to noncompartmental and empirical Bayes PK modeling, data were integrated with a previously studied data set comprising 25 infants and toddlers (aged 6-18 months). A two-compartmental model described the comprehensive data set. The population estimates of the R (+) isomer were (%CV): central volume of distribution 1130 (10%) ml, peripheral volume of distribution 626 (25%) ml, and clearance from the central compartment 7.40 (8%) ml·min(-1). Those of the S (-) isomer were 1930 (15%) ml, 319 (58%) ml, and 39.5 (13%) ml·min(-1). Typical elimination half-lives were 191 and 33 min, respectively. There was a trend for increased clearance and central volume with increasing age and weight. The base model suggested that clearance of the S (-) isomer was weakly related to age; however, when body size adjustment was added to the model, no covariates were significant. Safety assessment showed no changes in renal or hepatic function tests, surgical drain output, or continuous oximetry between groups. Cumulative morphine administration showed large inter-patient variability and was not different between groups.

CONCLUSION

Stereo-isomer-specific clearance of ketorolac in infants (aged 2-6 months) shows rapid elimination of the analgesic S (-) isomer as reported in infants aged 6-18 months. No adverse effects were seen after a single IV ketorolac dose.

Safety of ketorolac in neonates and infants after cardiac surgery

BACKGROUND

Ketorolac is an injectable nonsteroidal anti-inflammatory drug that is often used as a transitional short-term analgesic to treat moderate pain and to decrease opioid use. There is a paucity of literature documenting the safety of using ketorolac in neonates and infants after cardiac surgery.

METHODS

A retrospective chart review was performed which identified all patients <6 months of age who received ketorolac after cardiac surgery. Patients' demographic, surgical, and dosing data were collected. A Student's t-test was used to identify significant differences in renal and hematologic laboratory values at baseline and at 48 h of treatment.

RESULTS

A total of 53 children <6 months of age received at least one dose of ketorolac after cardiac surgery. Eleven of 53 children (21%) were <1 month of age. The blood urea nitrogen/serum creatinine (SCr) levels increased from baseline at 48 h of therapy in all infants, but stayed within normal limits. The largest increase in SCr level from baseline on any day of ketorolac therapy was 26 micromol x l(-1) (0.3 mg x dl(-1)) which occurred in two neonates. Four patients (three infants and one neonate) had minor episodes of bleeding while being treated with ketorolac. There were no clinically significant changes in hemoglobin, hematocrit or platelet count. None of these episodes caused hemodynamic instability nor required transfusion of blood products.

CONCLUSIONS

Ketorolac was used safely in neonates and infants who have had cardiac surgery at our institution. Ketorolac was not associated with any adverse hematologic or renal effects. Prospective investigation is warranted to further assess the safety and effectiveness of ketorolac in this patient population.

Postoperative analgesia in infants and children

PURPOSE OF REVIEW

Although postoperative analgesia in infants and children should be an integral part of the perioperative management, undertreatment of pain is not rare in clinical practice and may influence outcome and long term behaviour. Therefore, this review summarizes results of recent papers and discusses actual trends and future perspectives concerning postoperative pharmacologic pain therapy in infants and children.

RECENT FINDINGS

A multimodal approach using locoregional anesthesia and systemic analgesics is a widely accepted technique. New developments include new local anesthetics with a wider margin of safety and more experience with adjuvants, catheter techniques and systemic analgesics. Replacement of bupivacaine with ropivacaine may be prudent especially for prolonged epidural infusion, use in neonates, impaired hepatic metabolic function, and anesthetic techniques requiring large dosage of local anesthetic. The limited duration of analgesia after single blocks can be prolonged by use of adjuvants (clonidine, ketamine), catheter techniques or early use of systemic analgesics. Non-opioids (acetaminophen, non-steroidal anti-inflammatory drugs) are appropriate for patients with mild to moderate pain or as a component of multimodal pain therapy. Patient- and nurse-controlled analgesia are convenient ways for opioid administration in infants and children.

SUMMARY

The reviewed studies suggest that there are many reliable agents and techniques available to provide a safe and effective postoperative analgesia even in neonates and small infants.

Nonsteroidal anti-inflammatory drugs for postoperative pain: a focus on children

Pain is a common symptom after surgery in children, and the need for effective pain management is obvious. For example, after myringotomy, despite the brief nature of the procedure, at least one-half of children have significant pain. After more extended surgery, such as tonsillectomy, almost all children have considerable pain longer than 7 days. Nonsteroidal anti-inflammatory drugs (NSAIDs) are useful for postoperative pain management because surgery causes both pain and inflammation. Several pediatric studies indicate NSAIDs are effective analgesics in the management of mild and moderate pain. In the treatment of severe pain, NSAIDs should be given with acetaminophen (paracetamol) or opioids, and the use of an appropriate regional analgesic technique should be considered. NSAIDs are more effective in preventing pain than in the relief of established pain. Pain following surgery is best managed by providing medication on a regular basis, preventing the pain from recurring. This proactive approach should be implemented for any procedure where postoperative pain is the likely outcome. In children, the choice of formulation can be more important than the choice of drug. Intravenous administration is preferred for children with an intravenous line in place; thereafter mixtures and small tablets are feasible options. Children dislike suppositories, and intramuscular administration should not be used in nonsedated children. Ibuprofen, diclofenac, ketoprofen and ketorolac are the most extensively evaluated NSAIDs in children. Only a few trials have compared different NSAIDs, but no major differences in the analgesic action are expected when appropriate doses of each drug are used. Whether NSAIDs differ in the incidence and severity of adverse effects is open to discussion. Because NSAIDs prevent platelet aggregation they may increase bleeding. A few studies indicate that ketorolac may increase bleeding more so than other NSAIDs, but the evidence is conflicting. Severe adverse effects of NSAIDs in children are very rare, but it is important to know about adverse effects in order to recognize and treat them when they do occur. NSAIDs are contraindicated in patients in whom sensitivity reactions are precipitated by aspirin (acetylsalicylic acid) or other NSAIDs. They should be used with caution in children with liver dysfunction, impaired renal function, hypovolemia or hypotension, coagulation disorders, thrombocytopenia, or active bleeding from any cause. In contrast, it seems that most children with mild asthma may use NSAIDs.