Alfaxan and Peri-operative Analgesia
In the past, pain relief was considered less important than it is today. At that time, there was argument about the capacity of animals to feel pain, the advantage of pain being a natural immobilization agent and the difficulty in assessing the degree of pain being experienced. The last point is still an issue (even if the first point is not). The most referenced method for assessing pain is the Glasgow Composite Pain Scale,56 which can become a rapid assessment tool in clinical practice.
It is now universally acknowledged that reduction of pain greatly assists in recovery from surgery. To be most effective, pain relief should be initiated at the premedication phase, maintained across surgery and continued into the recovery phase.
Use of analgesia prior to procedures that cause pain is known as preemptive analgesia. Early administration of agents such as opioids can allay fear, stress and anxiety caused by the clinical environment, as well as reduce the required doses of anesthetic agents used during surgery - early pain control reduces the sensitization of neural pathways to painful stimuli. Use of adjunctive anxiolytic agents such as acepromazine or benzodiazepine, while not necessarily delivering extra analgesic effect, can augment the effects of opiate medications by decreasing sympathetic drive in the patient.
The administration of a number analgesic agents with different modes of action (e.g., opioids, local anesthetics, NSAIDs) can target more than one point in the nervous system, thus making the control of pain more effective. This multimodal approach may also reduce the required dose of each agent and hence lessen undesirable side effects.