Block that pain! (Proceedings)


Block that pain! (Proceedings)

Nov 01, 2010

Pain management is more than the latest popular terminology. It is an important part of veterinary dentistry. Many of the procedures performed on animals are painful and it is our duty as technicians to ensure that our patients are as comfortable as possible. The deliver of local nerve blocks prior to performing many dental procedures or oral surgery is a great way to create preemptive analgesia. This can often be incorporated into a multimodal plan for pain control.


The International Association for the Study of Pain defines pain as an unpleasant sensory or emotional experience associated with actual or potential tissue damage, or described in terms of such damage.

Pathophysiology of Pain

In order to manage pain, it is important to have a basic understanding of the complex interactions coming together to create the pain response. This will allow for formulating a plan to control pain prior to a procedure, during surgery and postoperatively. Nociception is defined as the processing of a noxious stimulus resulting in the perception of pain by the brain. Nociception has three distinct physiological processes, transduction, transmission and modulation. Transduction is the translation of physical energy (noxious stimuli) into electrical activity at the peripheral nociceptor. These receptors are considered mechanosensitive, thermosensitive and chemosensitive. Transmission transports these impulses along nerve fibers to the nucleus caudalis of the brain. These trigeminal afferent nerves are subdivided into two categories:
     • A-delta or fast fibers, responsible for sharp stabbing pain as in a sudden tooth fracture
     • C or slow fibers, responsible for dull throbbing pain as in trauma with internal hemorrhage and pressure.

Modulation is the synapse of the neurons in the nucleus caudalis in the medulla of the brain. This leads to the perception of pain. The goal of dental analgesia is to block this perception.

Consequences of Pain

Pain can be pathologic is left untreated. Pain can cause increased risk of infection, delayed wound healing, reduced food and water intake, inability to move, altered sleep patterns and altered behavior patterns. Some or all of these consequences may prolong convalescence and may predispose the patient to an adverse outcome.

Pain Recognition

Physiological signs of acute pain include increase blood pressure and heart rate, peripheral vasoconstriction that manifests itself as blanched membranes. Respiration rates can also increase. The manifestations of pain can be in dogs and cats. Dogs will often whine and whimper, become unusually timid or aggressive, have a fixed stare or have a restless behavior. Cats may purr, growl or groom when in pain. They may try to hide, appear to squint and be resistant to movement. An animal in pain may not have an appetite, have inappropriate urination, or stop grooming themselves.

Pain Assessment

Technicians have the primary role in assessing a patient's pain level. In order to assess a patient's pain level, you need to know what is normal. If at all possible become familiar with a patient presenting physiological values and behaviors at admission. A through pain assessment should include both watching the patient from a distance and an interactive assessment that encourages a response from the patient.

There are simple assessment scales that can be used to record the pain level of the patient. These include a visual analog scale and the numerical rating scale.
     • Simple Descriptive Scales (SDS)
     • Rate pain as none, mild, moderate, or severe
     • Numeric Rating Scales (NRS)
     • 0 being no pain to 10 being worse possible pain
     • Visual analogue Scale (VAS)
     • 100 mm ruler with 0 = no pain, and 100 = worst pain possible

The NRS or VAS scales, using the behavioral traits listed previously, by a single observer, is most likely the most reliable means of scoring a patients pain level.