Wound Soaker Catheters for Control of Post-Operative Pain in Dogs and Cats
Alicia Karas, Emily McCobb, Lois Wetmore, Cheryl Blaze
History and Rationale
One of this decade’s remarkable advances in managing post-surgical pain involves delivering local anesthetic directly to the wound, and is easily adopted for use in veterinary patients. Traditional nerve block techniques eliminate the pain of surgery but mastery can require significant expertise. In addition, commonly used local anesthetics have relatively short durations (lidocaine, 1 – 2 hours; bupivacaine, 4 – 6 hours). The availability of implantable infusion catheters makes it possible to use repeated dosing or continuous infusion of local anesthetics into surgical wounds, and improves pain control. FDA approved human use catheters are available, but costly. Two modestly priced catheters are commercially available for veterinary use (see below). Basically, they consist of a pliable catheter with tiny holes along the implanted end, functioning somewhat like a garden “soaker hose” (See figure 1a-c). The catheter is buried in the wound bed during surgical closure. Continue reading
Wound Soaker Catheters
At the Foster Hospital for Small Animals and Tufts Veterinary Emergency Treatment and Specialties (Tufts VETS), we have been using wound soaker catheters routinely since 2004 for infusion of lidocaine (dogs) and intermittent bupivacaine injection in cats after a variety of procedures. These include limb amputation, ear canal ablation, intercostal and sternal thoracotomy, celiotomy, and soft tissue tumor excision.
This dog, shown the evening after a thoracotomy, has a wound soaker catheter placed in a median sternotomy incision. Both the wound soaker (lowermost) and thoracic drain (uppermost) can be seen. He is ambulatory and comfortable.
Two of our anesthesiology/pain medicine specialists, Dr. Emily McCobb and Dr. Cheryl Blaze, collaborated with experts at Mila International (Erlanger, KY) to develop the competitively priced veterinary catheters. Qualitatively, we find that the pain relief afforded to patients is excellent. Dogs recovering from an intercostal thoracotomy will lie on the side of the incision, which suggests that they are quite comfortable. Perhaps the most compelling application is the use of wound soakers for limb amputation. In fact, the use of wound soaker catheters has become a common and preferred amputation pain management technique in many hospitals. Patients are comfortable upon recovery from anesthesia, will stand, walk and eliminate with ease, and generally will eat the first postoperative night. Continue reading
Anesthesia and Pain Case Challenge
History: An 8 year old, 30 kg, mixed breed dog presents with recent onset of left hind leg lameness. Radiographs and subsequent biopsy reveal the presence of an osteosarcoma of the distal femur. The decision to amputate the limb is made. How would you manage this dog’s acute perioperative pain using a wound soaker catheter? Calculate doses and volumes of local anesthetic needed to maintain pain control, and duration of treatment.