BJA Advance Access published online on February 6, 2004
British Journal of Anaesthesia, doi:10.1093/bja/aeh094
© 2004 by The Board of Management and Trustees of the British Journal of Anaesthesia
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Ninewells Hospital and Medical School, Dundee, Scotland DD1 9SY, UK
* To whom correspondence should be addressed. E-mail: g.a.mcleod{at}dundee.ac.uk.
Background. Spread of intrathecal local anaesthetics is determined principally by baricity and position of the patient. Hypobaric solutions of bupivacaine are characterized by an unpredictable spread of sensory block whereas addition of dextrose 80 mg ml-1 provides a predictable spread but to high thoracic levels. In contrast, dextrose concentrations between 8 and 30 mg ml-1 have shown reliable and consistent spread for surgery. Hence, the aim of this study was to determine the density of bupivacaine, levobupivacaine, and ropivacaine with and without dextrose at both 23 and 37°C before embarking on clinical studies. Methods. Density (mg ml-1) was measured using the method of mechanical oscillation resonance, accurate to five decimal places on 1250 samples. 500 density measurements were performed in a randomized, blind fashion at 23 and 37°C on 10 plain solutions of bupivacaine (2.5, 5, and 7.5 mg ml-1) levobupivacaine (2.5, 5, and 7.5 mg ml-1) and ropivacaine (2, 5, 7.5, and 10 mg ml-1). Following this, 750 density measurements were taken at 23 and 37°C on the 5 mg ml-1 solutions of bupivacaine, levobupivacaine, and ropivacaine with added dextrose (10, 20, 30, 50, and 80 mg ml-1). Results. There was a linear relationship between density and dextrose concentration for all three local anaesthetics (R2=0.99) at 23 and 37°C. The mean density of levobupivacaine 5 mg ml-1 was significantly greater than the densities of bupivacaine 5 mg ml-1 and ropivacaine 5 mg ml-1 after adjusting for dextrose concentration using analysis of covariance. This difference existed both at 23 and 37°C. The mean (SD) density of levobupivacaine 7.5 mg ml-1 was 1.00056 (0.00003) mg ml-1, the lower 0.5% percentile (1.00047 mg ml-1) lying above the upper limit of hypobaricity for all patient groups. Conclusions. The density of local anaesthetics decreases with increasing temperature and increases in a linear fashion with the addition of dextrose. Levobupivacaine 5 mg ml-1 has a significantly higher density compared with bupivacaine 5 mg ml-1 and ropivacaine 5 mg ml-1 at 23 and 37°C both with and without dextrose. Levobupivacaine 7.5 mg ml-1 is an isobaric solution within all patient groups at 37°C. Br J Anaesth 2004
Laboratory Investigation
Density of spinal anaesthetic solutions of bupivacaine, levobupivacaine, and ropivacaine with and without dextrose
Abstract 
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  F. Remerand, A. S. Vuitton, M. Palud, S. Buchet, X. Pourrat, A. Baud, M. Laffon, and J. Fusciardi Elastomeric Pump Reliability in Postoperative Regional Anesthesia: A Survey of 430 Consecutive Devices Anesth. Analg., December 1, 2008; 107(6): 2079 - 2084. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. F. Luck, P. D. W. Fettes, and J. A. W. Wildsmith Spinal anaesthesia for elective surgery: a comparison of hyperbaric solutions of racemic bupivacaine, levobupivacaine, and ropivacaine Br. J. Anaesth., November 1, 2008; 101(5): 705 - 710. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Dutta and A. Taneja Minimum Effective Dose of Bupivacaine Required for Transurethral Procedures Remains Uncertain Anesth. Analg., October 1, 2007; 105(4): 1170 - 1170. [Full Text] [PDF]
|
|
|
|
|
|
Y.-C. P. Arai, W. Ueda, E. Takimoto, and M. Manabe The Influence of Hyperbaric Bupivacaine Temperature on the Spread of Spinal Anesthesia Anesth. Analg., January 1, 2006; 102(1): 272 - 275. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. A. McLeod and M. O. Columb Moles, weights and potencies: freedom of expression! Br. J. Anaesth., July 1, 2005; 95(1): 110 - 111. [Full Text] [PDF]
|
|
|
|
|
|
G. Cappelleri, G. Aldegheri, G. Danelli, C. Marchetti, M. Nuzzi, G. Iannandrea, and A. Casati Spinal Anesthesia with Hyperbaric Levobupivacaine and Ropivacaine for Outpatient Knee Arthroscopy: A Prospective, Randomized, Double-Blind Study Anesth. Analg., July 1, 2005; 101(1): 77 - 82. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. H. Rosenberg and S. A. Schug Levobupivacaine base and levobupivacaine hydrochloride Br. J. Anaesth., April 1, 2005; 94(4): 544 - 544. [Full Text] [PDF]
|
|
|
|
|
|
P. D. W. Fettes, G. Hocking, M. K. Peterson, J. F. Luck, and J. A. W. Wildsmith Comparison of plain and hyperbaric solutions of ropivacaine for spinal anaesthesia Br. J. Anaesth., January 1, 2005; 94(1): 107 - 111. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Pitkanen and G. McLeod Density of spinal anaesthetic solutions Br. J. Anaesth., November 1, 2004; 93(5): 749 - 749. [Full Text] [PDF]
|
|