Vanquish the 3 most common pain management mistakes made in veterinary patients undergoing surgery.
Veterinary medicine has come a long way in its recognition and treatment of pain in animals. As a private practice veterinary anesthesiologist, I often consult with general practices that seek to improve the pain management for patients undergoing surgery. Here are three common mistakes with easy fixes to improve pain control in your practice.
1. Don't trust the fog
Inhaled gas anesthetics do not provide any analgesia. Although anesthetized patients do not consciously perceive pain, they can still have the physiologic response to a painful stimulus during surgery, as evidenced by increased respiratory and heart rates during painful surgical procedures. If other methods of pain control are not provided, then the level of gas anesthesia will most likely need to be increased, and this will surely compromise cardiopulmonary function. Furthermore, when this physiologic response to pain is not interrupted early, it can lead to pain that is more difficult to treat after surgery and abnormal pain states.
Thus, analgesics should be included in a premedication protocol before anesthetic induction. Patients will require significantly less pain medication after the surgery when analgesia is administered preoperatively-and they will more often have a smooth calm recovery.
During surgery, if your patient is continuing to have physiologic responses to surgery that require you to increase the setting on the vaporizer above what you think is standard for this type of operation, consider repeating a dose of injectable analgesics. The most common pain medications used during surgery are opioids. They are generally safe, and doses can be repeated even if the premedication was given within an hour. But note this is not true of buprenorphine; it has a ceiling effect, so you are unlikely to get an improvement with escalating doses.
(Getty Images)2. Boot the butorphanol for pain
Speaking of administering an opioid, butorphanol is an opioid commonly given before surgery for pain control. It also causes sedation, which facilitates the placement of an intravenous catheter. But in the past few decades, research has shown that butorphanol is a poor analgesic with a short duration of action. Furthermore, because butorphanol is a mu receptor antagonist, it may interfere with the efficacy of more potent and proven analgesics, such as hydromorphone, that are mu receptor agonists.
Butorphanol provides good sedation, but this can be mistakenly interpreted as comfort in patients that have pain. Thus, butorphanol is only recommended for sedation and not surgical pain. A better choice for pain control during surgery is hydromorphone or methadone.
3. Potent pain, mighty measures
When choosing an analgesic for a patient having surgery, one size does not fit all. Each type of surgery is associated with different amounts of pain. Orthopedic and abdominal surgeries are often associated with marked pain. Surgeries to remove small masses from the skin are associated with mild to moderate pain. It is important to anticipate this difference and choose an appropriate analgesic.
In addition, for extensive surgical procedures, additional analgesics that work via a different mechanism should be added-a concept known as multimodal analgesia. Using different analgesics that work by different mechanisms allows for superior pain control compared with any one drug alone. This also allows you to reduce the dose of each individual drug and, thus, minimize side effects.
Patients with well-controlled pain during and after surgery will have vastly improved recoveries. When patients are comfortable they are more likely to eat, maintain mobility and have earlier hospital discharges. These are often the concerns raised by clients after surgery and will put them at ease as well.
Andrea M. Caniglia, VMD, DACVAA
Center for Animal Referral and Emergency Services