Abstract
Objective: To determine plasma bupivacaine concentrations after retrobulbar or peribulbar injection of bupivacaine in cats. Study design: Randomized, crossover, experimental trial with a 2 week washout period. Animals: Six adult healthy cats, aged 1-2 years, weighing 4.6 ± 0.7 kg. Methods: Cats were sedated by intramuscular injection of dexmedetomidine (36-56 μg kg-1) and were administered a retrobulbar injection of bupivacaine (0.75 mL, 0.05%; 3.75 mg) and iopamidol (0.25 mL), or a peribulbar injection of bupivacaine (1.5 mL, 0.5%; 7.5 mg), iopamidol (0.5 mL) and 0.9% saline (1 mL) via a dorsomedial approach. Blood (2 mL) was collected before and at 5, 10, 15, 22, 30, 45, 60, 120, 240 and 480 minutes after bupivacaine injection. Atipamezole was administered approximately 30 minutes after bupivacaine injection. Plasma bupivacaine and 3-hydroxy-bupivacaine concentrations were determined using liquid chromatography-mass spectrometry. Bupivacaine maximum plasma concentration (Cmax) and time to Cmax (Tmax) were determined from the data. Results: The bupivacaine median (range) Cmax and Tmax were 1.4 (0.9-2.5) μg mL-1 and 17 (4-60) minutes, and 1.7 (1.0-2.4) μg mL-1, and 28 (8-49) minutes, for retrobulbar and peribulbar injections, respectively. In both treatments the 3-hydroxy-bupivacaine peak concentration was 0.05-0.21 μg mL-1. Conclusions and clinical relevance: In healthy cats, at doses up to 2 mg kg-1, bupivacaine peak plasma concentrations were approximately half that reported to cause arrhythmias or convulsive electroencephalogram (EEG) activity in cats, and about one-sixth of that required to produce hypotension.
| Original language | English (US) |
|---|---|
| Journal | Veterinary Anaesthesia and Analgesia |
| DOIs | |
| State | Accepted/In press - 2016 |
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Keywords
- Bupivacaine
- Cats
- Peribulbar anesthesia
- Plasma concentration
- Retrobulbar anesthesia
ASJC Scopus subject areas
- veterinary(all)
Cite this
Plasma bupivacaine concentrations following orbital injections in cats. / Shilo-Benjamini, Yael; Pypendop, Bruno H; Newbold, Georgina; Pascoe, Peter J.
In: Veterinary Anaesthesia and Analgesia, 2016.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Plasma bupivacaine concentrations following orbital injections in cats
AU - Shilo-Benjamini, Yael
AU - Pypendop, Bruno H
AU - Newbold, Georgina
AU - Pascoe, Peter J
PY - 2016
Y1 - 2016
N2 - Objective: To determine plasma bupivacaine concentrations after retrobulbar or peribulbar injection of bupivacaine in cats. Study design: Randomized, crossover, experimental trial with a 2 week washout period. Animals: Six adult healthy cats, aged 1-2 years, weighing 4.6 ± 0.7 kg. Methods: Cats were sedated by intramuscular injection of dexmedetomidine (36-56 μg kg-1) and were administered a retrobulbar injection of bupivacaine (0.75 mL, 0.05%; 3.75 mg) and iopamidol (0.25 mL), or a peribulbar injection of bupivacaine (1.5 mL, 0.5%; 7.5 mg), iopamidol (0.5 mL) and 0.9% saline (1 mL) via a dorsomedial approach. Blood (2 mL) was collected before and at 5, 10, 15, 22, 30, 45, 60, 120, 240 and 480 minutes after bupivacaine injection. Atipamezole was administered approximately 30 minutes after bupivacaine injection. Plasma bupivacaine and 3-hydroxy-bupivacaine concentrations were determined using liquid chromatography-mass spectrometry. Bupivacaine maximum plasma concentration (Cmax) and time to Cmax (Tmax) were determined from the data. Results: The bupivacaine median (range) Cmax and Tmax were 1.4 (0.9-2.5) μg mL-1 and 17 (4-60) minutes, and 1.7 (1.0-2.4) μg mL-1, and 28 (8-49) minutes, for retrobulbar and peribulbar injections, respectively. In both treatments the 3-hydroxy-bupivacaine peak concentration was 0.05-0.21 μg mL-1. Conclusions and clinical relevance: In healthy cats, at doses up to 2 mg kg-1, bupivacaine peak plasma concentrations were approximately half that reported to cause arrhythmias or convulsive electroencephalogram (EEG) activity in cats, and about one-sixth of that required to produce hypotension.
AB - Objective: To determine plasma bupivacaine concentrations after retrobulbar or peribulbar injection of bupivacaine in cats. Study design: Randomized, crossover, experimental trial with a 2 week washout period. Animals: Six adult healthy cats, aged 1-2 years, weighing 4.6 ± 0.7 kg. Methods: Cats were sedated by intramuscular injection of dexmedetomidine (36-56 μg kg-1) and were administered a retrobulbar injection of bupivacaine (0.75 mL, 0.05%; 3.75 mg) and iopamidol (0.25 mL), or a peribulbar injection of bupivacaine (1.5 mL, 0.5%; 7.5 mg), iopamidol (0.5 mL) and 0.9% saline (1 mL) via a dorsomedial approach. Blood (2 mL) was collected before and at 5, 10, 15, 22, 30, 45, 60, 120, 240 and 480 minutes after bupivacaine injection. Atipamezole was administered approximately 30 minutes after bupivacaine injection. Plasma bupivacaine and 3-hydroxy-bupivacaine concentrations were determined using liquid chromatography-mass spectrometry. Bupivacaine maximum plasma concentration (Cmax) and time to Cmax (Tmax) were determined from the data. Results: The bupivacaine median (range) Cmax and Tmax were 1.4 (0.9-2.5) μg mL-1 and 17 (4-60) minutes, and 1.7 (1.0-2.4) μg mL-1, and 28 (8-49) minutes, for retrobulbar and peribulbar injections, respectively. In both treatments the 3-hydroxy-bupivacaine peak concentration was 0.05-0.21 μg mL-1. Conclusions and clinical relevance: In healthy cats, at doses up to 2 mg kg-1, bupivacaine peak plasma concentrations were approximately half that reported to cause arrhythmias or convulsive electroencephalogram (EEG) activity in cats, and about one-sixth of that required to produce hypotension.
KW - Bupivacaine
KW - Cats
KW - Peribulbar anesthesia
KW - Plasma concentration
KW - Retrobulbar anesthesia
UR - http://www.scopus.com/inward/record.url?scp=84971422262&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84971422262&partnerID=8YFLogxK
U2 - 10.1111/vaa.12388
DO - 10.1111/vaa.12388
M3 - Article
C2 - 27216369
AN - SCOPUS:84971422262
JO - Veterinary Anaesthesia and Analgesia
JF - Veterinary Anaesthesia and Analgesia
SN - 1467-2987
ER -