Abstract | BACKGROUND: METHODS: Peripheral nerve catheters were placed for postoperative pain management in trauma patients and infused with ropivacaine 0.2% or bolused with 0.5%. Blood samples were obtained from each subject on days 0 (preinfusion), 3, 5, 7, 10, and every third day until catheter removal. Serum free ropivacaine concentrations were measured via high-performance liquid chromatography and were compared using the Wilcoxon signed rank test. RESULTS: One hundred thirty-three blood samples were analyzed in 35 patients; all serum free ropivacaine concentrations after infusion initiation (99 samples from 35 subjects) were below 0.34 mg/L (previously determined toxic threshold). The highest concentration achieved in a blood sample was 0.19 mg/L; all other values were <0.09 mg/L. The total amount of drug received during the study ranged from 1146 to 22,320 mg (median of 3722 mg). Catheters remained in situ for a median of 7 days (range: 3-23). From day 0 to 3 (preinfusion), 77% of the study participants had an increase in the serum free-fraction ropivacaine concentrations. The median concentration on day 3 was 0.025 mg/L (95% upper confidence limit for mean: 0.05, range: <0.01-0.19); P < 0.001 compared with preinfusion levels). From day 3 to 5, 68% of the participants had a decrease in the serum free ropivacaine concentrations (median level 0.016 mg/L [95% upper confidence limit for mean: 0.021] P = 0.007 for day 5 compared with day 3). CONCLUSIONS: In this study, free serum ropivacaine concentrations remained well below toxic values despite large amounts of drug administration in combat-wounded patients. The administration of continuous ropivacaine infusions over prolonged time periods, coupled with multiple drug boluses, did not produce toxic or near-toxic serum concentrations.
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Authors | Lisa Bleckner, Che Solla, Bader B Fileta, Robin Howard, Carlos E Morales, Chester C Buckenmaier |
Journal | Anesthesia and analgesia
(Anesth Analg)
Vol. 118
Issue 1
Pg. 225-9
(Jan 2014)
ISSN: 1526-7598 [Electronic] United States |
PMID | 24247226
(Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)
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Chemical References |
- Amides
- Anesthetics, Local
- Ropivacaine
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Topics |
- Adult
- Amides
(administration & dosage, adverse effects, blood)
- Anesthetics, Local
(administration & dosage, adverse effects, blood)
- Autonomic Nerve Block
(adverse effects, instrumentation, methods)
- Catheters, Indwelling
(adverse effects)
- Female
- Humans
- Male
- Middle Aged
- Ropivacaine
- Time Factors
- Young Adult
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