Density Change of Local Anesthetics and a Mixed Solution Can Be Estimated by Refractometry / 대한마취과학회지
Korean Journal of Anesthesiology
;
: 325-330, 2002.
Article
in Korean
| WPRIM
| ID: wpr-197407
ABSTRACT
BACKGROUND:
Baricity of the local anesthetics is a major determinant of the distribution of local anesthetics in CSF. The purpose of this study was to assess the value of refractometry in measuring the specific gravity of CSF, local anesthetics and adding solutions, and then comparing these to the density of CSF and local anesthetics.METHODS:
CSF samples were obtained from 30 patients during spinal anesthesia. 0.5% hyperbaric tetracaines were diluted with CSF to create a 11 to 110 density and specific gravity measurements were made at room temperature, using a refractometer. 2% lidocaine was diluted with distilled water, normal saline, 5% and 10% dextrose water to create 2%, 1%, 0.67%, 0.5% and 0% mixtures measured respectively.RESULTS:
Specific gravity of CSF was 1.0066 +/- 0.0006 and SG of 0.5% tetracaine was 1.0285 +/- 0.0028. The effect of specific gravity on the concentrations of tetracaine was determined by linear regression with r = 0.9803, y = 1.0060 + 0.0440 X x. Dilutions of 2% lidocaine with adding solutions were distilled water, y = 1.0008 + 0.0078 X x ; normal saline, y = 1.0056 + 0.0053 X x ; 5% dextrose, y = 1.0208 - 0.0022 X x ; and 10% dextrose, y = 1.0436 - 0.0135 X x.CONCLUSIONS:
The relationship between concentration and specific gravity of local anesthetics is linear. We conclude that refractometry is a reliable method to predict density of local anesthetics.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Refractometry
/
Specific Gravity
/
Tetracaine
/
Water
/
Linear Models
/
Glucose
/
Anesthesia, Spinal
/
Anesthetics, Local
/
Lidocaine
Type of study:
Prognostic study
Limits:
Humans
Language:
Korean
Journal:
Korean Journal of Anesthesiology
Year:
2002
Type:
Article
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