Effect of extradural anesthesia on postoperative complication rate in dogs undergoing total hip replacement: a prospective randomized equivalence study

The University of Florida College of Veterinary Medicine is currently recruiting dogs affected by hip joint disease requiring total hip replacement.

Enrolment Status: Currently Enrolling

Inclusion criteria: Dogs affected by hip dysplasia or osteoarthritis requiring total hip replacement at the University of Florida Veterinary Hospital are eligible to be enrolled. To participate, the dog must be healthy and weighing more than 10kg (11lb). There is no restriction related to breed or sex.

Exclusion criteria: Dogs undergoing total hip replacement because of a pelvic trauma or dogs in which revision total hip replacement surgery needs to be performed

Treatment: All dogs enrolled in this study will undergo total hip replacement according to our standard operating procedures, but they will be randomly allocated to one of the following groups:

– Group M: a preoperative extradural anesthesia with morphine will be performed

– Group BM: a preoperative extradural anesthesia with morphine and bupivacaine will be performed.

During surgery, your dog will be thoroughly monitored according to our standard operative procedures, despite the group allocation. Throughout hospitalization, the level of pain of your dog will be regularly evaluated and analgesic drugs administered as necessary to keep him/her comfortable. Furthermore, we will evaluate the ability of your dog to walk, the time to first urination and the amount of food eaten during hospitalization.

The day after the surgery, the dog will be walked on a specific mattress able to measure the force produced by the operated limb during walk.

Cost: There are no additional expenses for participating in this study. Clients will be responsible for all clinic costs and drug treatments as appropriate. An estimate of costs for which you will be responsible will be prepared for you at the time of admission.

Contacts: You can contact our Small Animal Hospital at (352) 392-2235, or complete the Study Interest Form to see if your dog qualifies.

Background: Total hip replacement is performed in dogs affected by severe hip joint disease. Extradural anesthesia is the administration of a drug (i.e. bupivacaine) in the proximity of the spinal cord that causes a temporary loss of sensation of the dog’s back limbs. The use of extradural anesthesia in dogs undergoing total hip replacement can reduce pain and the amount of general anesthetic needed during surgery.

Major complications requiring a second surgery have been reported in about 10% of dogs after total hip replacement. It has been speculated that complications might be more likely if extradural anesthesia with bupivacaine is used. However, a recent study performed in the United Kingdom found that only 5.8% of dogs needed revision surgery after total hip replacement, despite extradural anesthesia being performed. Furthermore, none of these complications occurred during the first 24 hours post-surgery, reducing the likelihood that extradural anesthesia played a role in their development. To confirm those results, we would like to perform this study to prove

that extradural anesthesia will not affect the post-surgical complication rate and the need for revision surgery, but will decrease the overall pain and analgesic consumption, improve the postoperative food intake, facilitating the recovery process of your dog.


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