Assessment of the tissue diffusion of anesthetic agent following administration of a low palmar nerve block in horses.
J Am Vet Med Assoc
; 239(10): 1334-40, 2011 Nov 15.
Article
in En
| MEDLINE
| ID: mdl-22044331
ABSTRACT
OBJECTIVE:
To investigate tissue diffusion of anesthetic agent following administration of low palmar nerve blocks (LPBs) in horses.DESIGN:
Randomized clinical trial. ANIMALS 12 adult horses. PROCEDURES In 9 horses, mepivacaine hydrochloride-iohexol (5050 dilution) injections were administered bilaterally (2 or 4 mL/site) to affect the medial and lateral palmar and palmar metacarpal nerves (4 sites). Lateral radiographic views of both metacarpal regions were obtained before and at 5, 15, 30, 60, 90, and 120 minutes after block administration; proximal and distal extents of contrast medium (and presumably anesthetic agent) diffusion from palmar and palmar metacarpal injection sites were measured and summed to determine total diffusion. Methylene blue solution was injected in forelimbs of 3 other horses that were subsequently euthanized to determine the potential route of anesthetic agent diffusion to the proximal suspensory ligament region.RESULTS:
Mean extents of proximal and total contrast medium diffusion were 4.0 and 6.6 cm, respectively, for the palmar metacarpal nerves and 4.3 and 7.1 cm, respectively, for the palmar nerves. Subtle proximal diffusion secondary to lymphatic drainage was evident in 17 of the 18 limbs. Contrast medium was detected in the metacarpophalangeal joint or within the digital flexor tendon sheath in 8 and 7 limbs, respectively. In the cadaver limbs, methylene blue solution did not extend to the proximal suspensory ligament region. CONCLUSIONS AND CLINICAL RELEVANCE In horses, LPBs resulted in minimal proximal diffusion of anesthetic agent from the injection sites. Limbs should be aseptically prepared prior to LPB administration because inadvertent intrasynovial injection may occur.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Iohexol
/
Horses
/
Anesthesia, Local
/
Anesthetics, Local
/
Mepivacaine
/
Nerve Block
Type of study:
Diagnostic_studies
Limits:
Animals
Language:
En
Journal:
J Am Vet Med Assoc
Year:
2011
Document type:
Article
Affiliation country:
Estados Unidos