Segmental thoracolumbar subarachnoid analgesia in cows
Skarda, R.T.; Muir, W.W.
American Journal of Veterinary Research 42(4): 632-638
1981
ISSN/ISBN: 0002-9645 PMID: 7332125 Document Number: 176854
A new technique for producing segmental subarachnoid analgesia in adult cows without causing complete loss of locomotor control is described. Segmental subarachnoid analgesia was produced in 18 adult nonpregnant Holstein-Friesian cows. A 17-gauge Huber point directional needle was used to place a catheter with a stylet into the subarachnoid space at the lumbosacral intervertebral space and advance it craniad to the thoracolumbar intervertebral space. The position of the catheter was confirmed radiographically in 8 cows. A 5% solution of procaine hydrochloride was injected through the catheter. The volume injected varied between 1.5 ml (8 cows) and 2 ml (10 cows). The rate of injection was approximately 0.5 ml/30 s. In 5 cows, 1.5 or 2 ml of normal saline solution was injected intrathecally 1 hour before the injection of procaine hydrochloride. These cows served as the control group. Segmental analgesia was achieved 7 to 10 minutes after completing the procaine hydrochloride injection and extended between spinal cord segments T9 and L4 on one or both sides of the spinal cord. The average duration of analgesia, as determined by response to superficial and deep muscular pinprick stimulation at the I1 dermatome, was 43.7 +/- 17.6 minutes, with a range of 22 to 80 minutes. Significant decreases (P less than 0.05) in respiratory rate and rectal temperature and increases in heart rate and subcutaneous temperature occurred in cows given procaine hydrochloride. The clinical application of the technique was demonstrated in one surgical procedure described. The advantages and disadvantages of segmental subarachnoid analgesia compared with segmental epidural analgesia are discussed.