title: Comparison of 5 mg tetracaine diluted in 1 ml, 2 ml and 4 ml of 10% glucose for spinal anesthesia.
abstract: The influence of variations in the volume of injectate when maintaining an identical dose of a hyperbaric local anesthetic has not previously been investigated when performing spinal anesthesia. This study compares spinal anesthesia of 5 mg of lyophilized tetracaine diluted in 1 ml, 2 ml or 4 ml of 10% glucose in 45 elderly patients undergoing elective hip surgery. While supine and horizontal, each patient received double-blind one of the three solutions through a catheter inserted 4 cm into the intrathecal space at the L2-L3 or L3-L4 interspace. No difference in the anesthetic effects was found between the three groups. The median value of the maximal sensory level was T6 (range T3-L2), T4 (range T3-T9) and T5 (range T3-T11) in the 1-ml, 2-ml, and 4-ml groups, respectively. The number of patients with a motor blockade of grade 2 or 3 was 12/15, 14/15 and 13/15, and the time from the initial dose to the need for the first top-up dose (mean +/- s.d.) was 88 +/- 35 min, 75 +/- 15 min and 68 +/- 15 min for the 1-ml, 2-ml and 4-ml groups, respectively. Hemodynamic changes were also comparable between the three groups. The authors conclude that in elderly patients, undergoing spinal anesthesia while supine and horizontal, variations in volume from 1 to 4 ml do not influence the characteristics of hyperbaric spinal anesthesia while injecting an identical dose of local anesthetic.
authors.affiliation: Department of Anesthesia, University Hospital of Geneva, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Gaggero
authors.forename: E
authors.initials: E
authors.lastname: Van Gessel
authors.forename: A
authors.initials: A
authors.lastname: Forster
authors.forename: P
authors.initials: P
authors.lastname: Gosteli
authors.forename: Z
authors.initials: Z
authors.lastname: Gamulin
mesh_terms: D000368:Aged; D000775:Anesthesia, Spinal / Q000379:methods*; D017558:Elective Surgical Procedures; D005947:Glucose / Q000008:administration & dosage*; D006622:Hip Prosthesis; D006801:Humans; D013748:Tetracaine / Q000008:administration & dosage*
chemical_list: D013748:Tetracaine; D005947:Glucose