Related Experiment Videos
Smaller children have greater bupivacaine plasma concentrations after ilioinguinal block
1Department of Anaesthesiology and Intensive Care Medicine, University Hospital, Schwanenweg, Germany.
Insights
Smaller children (10-15 kg) had higher bupivacaine plasma concentrations after ilioinguinal block than larger children (15-30 kg). The maximum safe plasma concentration of bupivacaine in small children is likely around 4 mg/L.
Area of Science:
- Pediatric Anesthesiology
- Pharmacokinetics
- Pain Management
Background:
- Ilioinguinal block is a common surgical procedure in children.
- Bupivacaine is a widely used local anesthetic for this procedure.
- Understanding bupivacaine pharmacokinetics in different pediatric age groups is crucial for safe dosing.
Purpose of the Study:
- To measure and compare plasma concentrations of bupivacaine after ilioinguinal block in children of different weight categories.
- To assess the pharmacokinetic differences in bupivacaine handling between smaller and larger children.
- To inform safe dosing recommendations for bupivacaine in pediatric ilioinguinal blocks.
Main Methods:
- Plasma bupivacaine concentrations were measured in 14 children (10-15 kg) and 17 children (15-30 kg) after receiving 0.25 ml/kg of 0.5% bupivacaine.
- Blood samples were collected at multiple time points (5, 10, 15, 20, 30, and 60 minutes) post-block.
- Statistical analysis was performed to compare maximal concentrations between the two groups.
Main Results:
- Mean maximal bupivacaine plasma concentration was significantly higher in the 10-15 kg group (1.5 mg/L) compared to the 15-30 kg group (0.9 mg/L).
- Unexpectedly high bupivacaine concentrations (up to 4 mg/L) were observed in smaller children, with levels often remaining elevated at 60 minutes.
- These findings suggest altered bupivacaine handling in smaller pediatric patients.
Conclusions:
- Smaller children (<15 kg) exhibit different pharmacokinetic handling of bupivacaine compared to larger children.
- The maximum safe plasma concentration of bupivacaine in small children is estimated to be approximately 4 mg/L.
- A bupivacaine dose of 1.25 mg/kg should not be exceeded for ilioinguinal blocks in children weighing less than 15 kg.
Abstract:
We have measured plasma concentrations of bupivacaine after ilioinguinal block in children of different sizes. We studied 14 children with weights 10-15 kg and 17 children with weights 15-30 kg. Each child received 0.5% bupivacaine 0.25 ml kg-1 (1.25 mg kg-1) (Carbostesin, Astra, Germany). Venous blood was obtained before the block (control) and at 5, 10, 15, 20, 30 and 60 min after block. Mean maximal concentration in the 10-15-kg group (1.5 (SD 0.9) mg litre-1, range 0.43-4.0 mg litre-1, at 18 (5) min) was significantly higher (P < 0.05) than that in the 15-30-kg group (0.9 (0.3) mg litre-1 range 0.35-1.34 mg litre-1, at 16 (5) min). In the 10-15-kg group, unexpectedly high (up to 4 mg litre-1) bupivacaine concentrations were observed and often concentrations remained high (> 2 mg litre-1) at 60 min. We conclude that smaller children appear to differ in the pharmacokinetic handling of bupivacaine. The maximum safe plasma concentration of bupivacaine in small children, although not clearly established, is likely to be approximately 4 mg litre-1. We recommend, therefore, that a dose of bupivacaine 1.25 mg kg-1 should not be exceeded in the perioperative period when performing ilioinguinal block in children < 15 kg in weight.