Is it pressure or pain?
Wednesday, 7th November, 2007
This magic machine, our body, has the ability to respond to foreign substances just as the beautiful swan constantly removes old feathers to make room for fresh ones. Our body is like a gatekeeper in order to ensure a state of perfect homeostasis. There are times when pharmacological intervention dictates the necessity in order to correct certain ailments. For example psyllium fibre may be absent in our diet and as such, a supplement maybe required in order to reestablish normal regularity. However when a pharmacological intervention is the preferred plan of action to assist in treating a condition, it is the responsibility of the clinician or pharmacist to make sure the drug is taken properly and in accordance with the product monograph as issued by FDA or some other regulatory agency. Failing to follow these instructions can result in a response, which can be out of phase by 180 degrees.
There are numerous examples where the opposite effect is predominating when the drug is administered incorrectly. Depending on the drug, there is some minimal room for small errors. However; by and large, the rule of thumb is strict adherence to the written or spoken word by your clinician or pharmacist. Then there is the experimental phase of drugs, whereby longitudinal studies do reveal new indication for drugs that never existed when they were first investigated. Aspirin is one obvious compound that keeps going and going and going.
This article is limited to dental procedures and the drugs, which may be necessary to complete a procedure. If per chance the local anesthetic is deposited as little as one MM off the intended target, The response can produce results that are as equally scary for the patient as it is for the dentist. The fundamental response can be traced to the base or foundation of one’s every day management of stress. The “flight or fight” response, originally discovered by Harvard physiologist Walter Cannon in (1915) where the hormone adrenaline or epinephrine, secreted endogenously to produce the physiologically normal response to cope with any potentially stressful situation.
What are the saber tooth tigers of today and why are they so dangerous?
Fortunately, in our modern world we are not exposed to foraging for our daily sustenance, as did the cave man. However our hormones cannot determine the origin of stress and do respond in exactly the same way as did our fore parents.When we experience excessive stress, whether from internal worry or perceived external discomfort, bodily reaction can be triggered and can be organic or psychogenic. Nerve cells firing will activate the well-known chemical adrenaline (epinephrine). The Sympathetic Nervous System (SNS) is a branch of our autonomic nervous system. It is always active at a basal level called sympathetic tone and becomes more active during times of stress. In other words, stress is the condition that results when our environment transactions lead us to perceive a variance, whether real or not, between the demands of a situation and the resources available to us, whether they be real (biological or psychological).
Today, however, most of the saber tooth (no pun intended) tigers we encounter are not a threat to our physical survival. Today’s saber tooth tigers consist of rush hour traffic, single parent management, missing a deadline, bouncing a check or having an argument with our spouse. Nonetheless, these modern day episodes trigger the same adrenaline release. Road rage, is relatively new, but is a classic example of how powerful and alive is our autonomic nervous system. Homeostasis must be maintained at all times and our autononic nervous system will go to all extent to see that perfect condition is mainained and stable.When one has not been keeping regular visits with their dentist, there is a basic guilt that is inscribed in one’s brain. For most of us, it started during childhood. It was that nightly ritual…“have you brushed your teeth?. This question has attained, some degree of noterity status in western society. For example the book, The fairy tooth godmother where an exchange for something that has lost its usefulness (such as a tooth) for something of everlasting value carries significant personal values and stays with one, even after one has flown the coup.
The body’s defences start to produce more endogenous epinephrine to balance the perceived threat of pain and the personal guilt that accompanies these situations. Guilt is powerful and can trigger our autonomic nervous ststem.Ironicly, the drug (local anesthetic) which the dentist most likely will be using, contains epinephrine. My earlier example of how therapeutic substances can produce more than one effect; dependant of how and where that drug is administered could not be more relevant than as in this scenario. The dentist needs to deposit the local anesthetic to bathe the nerve in such a way that it restricts or blocks any sensory impulses. This is called vasoconstriction.
It restricts the flow of blood in that specific area allowing the patient to be comfortable and without sensation of pain. Let us for the sake of comparison; see the effect of what would have been the result if the same drug had been administered into the vessel. The same drug would have affected vasodilatation or the opposite desired effect whereby anxiety and stress would be manifested. The experienced dentist has anatomical landmarks, which acts as the safety net and, which more or less reduces any accidental error.
The emphasis here is not to enter into clinical diagnosis, but rather to raise the profile of pharmacodynamics in a world of ever changing medications. Drugs administered incorrectly or directed to unintended receptors, will produce undesirable side effects. As clinicians have found it necessary to specialize, I for see the day for specialized pharmacists. The complexity of structural algorithm of compounds is already exceeding our capacity.
Comments to author. mailto:localanesthetics@yahoo.ca
Author: M.Sc. PharmD. CCPE
