Stable plasma concentrations of unbound ropivacaine during postoperative epidural infusion for 24–72 hours in children:

Off-label use of prescription analgesics among hospitalized children in the United States

PURPOSE

Analgesics are the most frequently administered medications among hospitalized children. However, current analgesic prescribing patterns have not been well defined among hospitalized children. In addition, it is unknown what proportion of prescription analgesics is approved for use in children and what proportion is used "off-label."

METHODS

Nationally representative data from 52 tertiary care children's hospitals in the Pediatric Health Information System were queried to determine prescribing rates of analgesic medications. We analyzed hospitalizations for children <18 years occurring between 1 April 2010 and 30 June 2018. Food and Drug Administration (FDA) drug labels were reviewed for pediatric information, and prescriptions were classified as on- or off-label based on age, route, and formulation.

RESULTS

Among 4.9 million hospitalizations, 1.8 million (37.6%, 95% confidence interval [CI] = 37.6-37.7) were associated with use of a prescription analgesic. Overall, 36.7% (95% CI = 36.7-36.7) of hospitalizations included off-label analgesic therapy, with 26.4% (95% CI = 26.4-26.5) associated with two or more off-label analgesics. Off-label analgesic use was higher among hospitalizations in the intensive care unit (61.5%) or with an operating room procedure (92.8%). Rates of off-label prescribing increased with age, peaking at 50.5% for adolescents. Prescription analgesics administered most frequently were morphine, fentanyl, and ketorolac, with off-label use occurring in 24.5%, 23.1%, and 11.3% of hospitalizations, respectively.

CONCLUSIONS

Over a third of pediatric hospitalizations were associated with the administration of prescription analgesics that have not been labeled for use in children. Our findings highlight the critical need to ensure that safe and effective analgesics are developed for children and that pediatric labeling is expanded for existing analgesics to inform treatment decisions.

Early experiences with the use of continuous erector spinae plane blockade for the provision of perioperative analgesia for pediatric liver transplant recipients

OBJECTIVE

Pediatric liver transplantation presents a number of anesthetic challenges, especially in providing adequate perioperative analgesia. In an effort to reduce opioid consumption and improve functional outcomes following pediatric liver transplantation, we have instituted a novel analgesia protocol centered on the provision of continuous regional analgesia with erector spinae plane (ESP) blockade.

CASES

We describe preincisional bilateral ESP catheter placement in two pediatric patients undergoing orthotopic liver transplantation. The first case was a 12-year-old boy with maple syrup urine disease undergoing initial transplantation and the second case was an 8-year-old boy who underwent an 11 hours complex redo liver transplant in the setting of glycogen storage disease type 1A requiring initial liver transplant in 2014. The 8-year-old boy presented to the operating suite with acute Budd-Chiari syndrome with comorbid ascites and a large right pleural effusion. In both cases, ESP blockade resulted in good analgesia, markedly reduced intraoperative and postoperative opioid consumption as compared with institutional data and published rates of consumption and was associated with rapid return of bowel function.

CONCLUSIONS

These early experiences suggest a role for continuous ESP blockade to improve analgesia and potentially change the paradigm of treatment in this fragile patient population. The technique should be considered in similar interventions. Further study will be undertaken to validate our observation.

Ropivacaine Plasma Concentrations after 192-Hour High Dose Epidural Ropivacaine Infusion in a Pediatric Patient without Side Effects

This case report discusses continuous epidural administration of ropivacaine 0.56 mg kg⁻¹ h ⁻¹ for 8 days in a 7-year-old trauma patient to prevent pain, after performing a lower right and upper left leg guillotine amputation. Venous sampling after 8 days revealed bound and unbound ropivacaine concentrations of 1.1 mg/l and 0.06 mg/l in plasma, respectively. Arterial sampling for bound and unbound ropivacaine was 1.2 mg/l and 0.05 mg/l in plasma, respectively. In this case report, long-term high dose epidural infiltration of ropivacaine did not result in severe side effects or complications. Further studies are needed to explore safety of these concentrations in larger populations of children.

A comparison of paravertebral nerve block catheters and thoracic epidural catheters for postoperative analgesia following the Nuss procedure for pectus excavatum repair

INTRODUCTION

Thoracic epidurals (TE) have been advocated as a superior method for controlling postoperative pain after repair of pectus excavatum with a Nuss procedure. However, three recent reports of permanent neurologic injury after the Nuss procedure with concurrent TE analgesia have raised concerns about the safety of this combination. Paravertebral nerve blocks (PVNB) are used successfully for analgesia of the chest, but no studies are available comparing TE and PVNB catheters for postoperative analgesia in this patient population. This study was conducted to compare the efficacy of PVNB catheters with TE catheters for postoperative analgesia in pediatric patients undergoing the Nuss procedure.

METHODS

We retrospectively reviewed the medical records of 20 adolescent males undergoing a thoracoscopic Nuss procedure with either bilateral PVNB catheters (n = 10) or TE catheter (n = 10) and compared postoperative opiate consumption and pain scores.

RESULTS

There were no statistically significant differences between the groups with respect to demographics, opiate consumption measured in morphine equivalents, and pain scores.

DISCUSSION

In this small series, bilateral PVNB catheters resulted in equivalent opioid consumption and pain scores when compared to TE for postoperative pain management in pediatric patients undergoing the Nuss procedure. Large prospective studies are needed to further compare the efficacy, incidence of side effects, and complications of TE and PVNB catheters for postoperative analgesia in this pediatric population.

Ultrasound-guided approach to the paravertebral space for catheter insertion in infants and children

BACKGROUND

Paravertebral perineural blocks are used to prevent pain in the thoracoabdominal dermatomes. Traditionally, a landmark-based technique is used in children, while ultrasound-guided (UG) techniques are being employed in adult patients.

OBJECTIVE

To describe an UG technique for placement of thoracic paravertebral nerve block (TPVNB) catheters in pediatric patients.

METHODS

Retrospective chart review of a series of 22 pediatric patients' ages 6 months to 17 years with weights from 6.25 kg to 135 kg using a transverse in-plane technique. Catheters were placed both bilateral and unilateral for a variety of thoracic and abdominal procedures. A linear ultrasound transducer was used in all cases with frequency of oscillation and transducer length chosen based on individual patient characteristics of age, weight, and BMI.

RESULTS

The median pain scores at 12, 24, 36, and 48 h were 1.2 (interquartile range, 4.5), 0.84 (interquartile range 3.0), 1.6 (interquartile range 2.9), and 0.83 (interquartile range 1.74), respectively. The median dose of opioid expressed as morphine equivalents consumed during the first 24 h after surgery was 0.14 mg·kg(-1) (interquartile range, 0.78 mg·kg(-1) ) and from 24 to 48 h the median dose was 0.11 mg·kg(-1) (interquartile range 0.44 mg·kg(-1) ). No complications were noted, and catheters were left an average of 3 days with a range of 1-5 days with good pain relief.

CONCLUSION

This technical description demonstrates the feasibility of placing PVNB catheters using a transverse in-line ultrasound-guided technique in a wide range of pediatric patients.

Local anesthetics and their adjuncts

Local anesthetics (LA) block propagation of impulses along nerve fibers by inactivation of voltage-gated sodium channels, which initiate action potentials (1). They act on the cytosolic side of phospholipid membranes. Two main chemical compounds are used, amino esters and amino amides. Amino esters are degraded by pseudocholinesterases in plasma. Amino amides are metabolized exclusively by the liver. Only amide LAs will be considered in this article.

Epidural ropivacaine versus ropivacaine plus tramadol in postoperative analgesia in children undergoing major abdominal surgery: a comparison

PURPOSE

In this study, we aimed to compare the effects of ropivacaine alone and ropivacaine plus tramadol administered epidurally for postoperative analgesia in children.

METHODS

Following Ethics Committee approval and informed parent consent, 44 children aged between 2 and 12 years, with ASA physical status I or II, who were undergoing major abdominal surgery were included in the study. Following tracheal intubation, patients were placed into lateral decubitus position and an epidural catheter (22-24 G) was inserted by using a Tuohy needle. Patients were randomly divided into two groups to receive either ropivacaine alone (0.2%), 0.7 ml/kg, in group I, or ropivacaine (0.2%) plus tramadol (2 mg/kg), with total volume 0.7 ml/kg, in group II, epidurally in both groups. Hemodynamic variables, pain and sedation scores, duration of analgesia, and side effects were recorded postoperatively.

RESULTS

The duration of analgesia was significantly longer in group RT than in group R (298.6 ± 28 and 867.9 ± 106.8 min in group I and II, respectively) (P < 0.05). CHEOPS scores were significantly lower in group RT at 30 min, 45 min, and 3 h postoperatively than in group R (P < 0.05). However, sedation scores were similar between the two groups. Twenty-two patients (100%) in group R and 13 patients (59%) in group RT needed supplemental analgesia postoperatively. There were no significant differences in side effects between the groups.

CONCLUSION

In children undergoing major abdominal surgery, epidural tramadol, added to epidural ropivacaine, provided lower pain scores, longer duration of analgesia, and lower postoperative analgesic requirement.

Optimizing pediatric dosing: a developmental pharmacologic approach

Many physiologic differences between children and adults can result in age-related differences in pharmacokinetics. Understanding the effects of age on bioavailability, volume of distribution, protein binding, hepatic metabolic isoenzymes, and renal elimination can provide insight into optimizing doses for pediatric patients. We performed a search of English-language literature using the MEDLINE database regarding age and pharmacokinetics (1979-July 2008). We then evaluated the literature with an emphasis on drugs with one primary elimination pathway, such as renal clearance or a pathway involving a single metabolic isoenzyme. Our mechanistic-based analysis revealed that children need weight-corrected doses that are substantially higher than adult doses for drugs that are metabolically eliminated solely by the specific cytochrome P450 (CYP) isoenzymes CYP1A2, CYP2C9, and CYP3A4. In contrast, weight-corrected doses for drugs eliminated by renal excretion or metabolism involving CYP2C19, CYP2D6, N-acetyltransferase 2, or uridine diphosphate glucuronosyltransferases are similar in children and adults. In children, bioavailability of drugs with high first-pass metabolism is decreased for drugs metabolized by CYP1A2, CYP2C9, and CYP3A4. Limited data suggest that by age 5 years, bioavailability of drugs affected by efflux transporters should be equivalent to that of adults. Using a pharmacokinetics-based approach, rational predictions can be made for the effects of age on drugs that undergo similar pathways of elimination, even when specific pharmacokinetic data are limited or unavailable.

Current world literature

This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 February 2008 and 31 January 2009 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.