Before describing the main procedures for the study of pain, have to put such a study in its context, addressing a key issue in its approach: the subjectivity of pain. We consider it necessary for the claim that pain is something subjective is formulated (and accepted) as a final argument justifying the futility of further inquiries. Not wanting to fall into epistemological speculation, can not be do some methodological remarks that, basically, are summarized in the fact that subjectivity and objectivity are not properties phenomena but the methods with which they are studied. (2)
Therefore, the question of subjectivity or objectivity - pain and in general - should move to another plane: the information or, better said, the informational value of the data and their interpretation. It is said that a phenomenon is subjective when certain features information on it, or its interpretation. Since the origin of the connotation of subjective or objective resides in the linguistic practices of researchers, the most consistent procedure to clarify the meaning is to analyze such practices and conditions of use of the terms that are given.
In the terms of use, we see that clinicians do not raise the issue of the subjectivity of pain in any case, but in very specific situations: for example, it is rare that it arises before an acute pain and even more so when it is superficial. The information that the patient provides not only is not questioned, but that is used by the clinician, who used the Guide to perform the diagnosis and to assess their therapeutic efficacy. This occurs, for example, birth control and a sciatica diagnosis. What defines the situations in which does not arise the subjectivity of pain? basically the fact that the following characteristics are given: they contain a lot of information, from different sources, an important part of this information is shared by doctors and patient and the data obtained are consistent. Injury indicators to match the intensity of the complaints of the patient, there is a clear relationship (or, at least, understandable and predictable) between exploratory findings and information that the patient provides professional expectations based on their knowledge. Consequently, the data are consistent and not ambiguous, the its informative value is high and so is, naturally, its predictive value. (8)
The second source of reference affects behavior scientific researchers. Fortunately for the development of science, no problem, and much less than the subjectivity, has failed never deter the need to continue investigating. Instead, the finding of a problem has been always sunset point-to-point procedures to override or counteract its influence or, in any case, to put it better. Precisely
in science takes as a premise that scientists are dubiously objectives and means to counteract the influence of their subjectivity is based scientific method.
in science takes as a premise that scientists are dubiously objectives and means to counteract the influence of their subjectivity is based scientific method.
Also a mechanical Act is part of the premise that never information is not fully shared nor the interpretation of the data: this is the basis the methodological principles in the detection, assessment and interpretation of the data. One of these principles is the value given to the evidence. As we have already said, the question that best characterize the way of thinking of the scientists probably: "do you, as know it?". That is, tests support or argue his claim?
Until the researcher is not capable of providing these tests, their statements are not scientists, are not "objective". Saying in a way somewhat blunt, until they do not provide more sources of information that can be shared, a statement like "the universe is expanding" is so subjective as "is a pain that drags me inside". (13)
To avoid the pitfalls of the unilateral interpretation, also there are other resources: the agreement between observers, making the procedures for information (experiments) in order to permit its replication and
the rules, statistical or methodological in general, the handling and interpretation of the data. All of them have as common denominator the fact references or information to share, based on the evidence supporting claims. If we rely on the analysis of behavior clinicians and scientists, we have a guide on how to guide the study of chronic pain.
the rules, statistical or methodological in general, the handling and interpretation of the data. All of them have as common denominator the fact references or information to share, based on the evidence supporting claims. If we rely on the analysis of behavior clinicians and scientists, we have a guide on how to guide the study of chronic pain.
It must be to raise the best information possible, the more value. In a Word, to do one little ambiguous phenomenon as acute pain. This objective is divided in two parts. Firstly, articular regarding estimates or reports of pain. These references must meet the condition of being clear, easy to identify and to be common to the professional and the patient: otherwise, must be in such a way that one and the other have the same access to the information they provided. This is what "objectify" - which does not mean 'measure' - pain.
This is the function that meet the anchors, whose use implies
establishing observable and easily identifiable categories of behaviors or other parameters, that can serve as reference for each of the estimates or potential reports. The second part of the goal consists of tuning the data and return more narrow and consistent, the relationships between them. This is reduced to very clearly stated the conditions for submission of reports or estimates of the patient. If a particular report appears systematically in certain conditions and never in others, then and only then get informative value.
establishing observable and easily identifiable categories of behaviors or other parameters, that can serve as reference for each of the estimates or potential reports. The second part of the goal consists of tuning the data and return more narrow and consistent, the relationships between them. This is reduced to very clearly stated the conditions for submission of reports or estimates of the patient. If a particular report appears systematically in certain conditions and never in others, then and only then get informative value.
This does not necessarily mean that the functions are linear, but which can be complex and imply that the relationship is only systematic in a given context. But, in any case, we've specified the conditions of the phenomenon and therefore know it.
If I can appreciate without ambiguity that estimates systematically coincide with certain movements or efforts, or coincide when they occur in a given context, constituted, for example, from lack of sleep, the patient report has all the informative value I need.
Hence the convenience worry above all to answer the question "when" and, in a general manner, rush study methods to specify very exhaustively the conditions and situations in which there are different estimates or reports of pain. Finally, we must remember - once more-that everything you have said is both for the information that it collects and uses the professional as to which collects, uses and provides the patient. (20)
It should not be forgotten that the first reason for bad information resides in the own subject of study, the difficulty of identifying many of the components, demonstrations and facets that make up the chronic pain. Not
is that the patient report wrong by intrinsic perversion: is that the difficulties are own stuff on which to report. The approach that we have proposed, in the end, does not constitute more than an attempt to put at the disposal of the patient the same resources that science uses to deal with the same problem: of lack of quality of managed information. In the words of a researcher in this field, the majority of resources
methodological study of pain are nothing more than means to help the patient to report. (23)
is that the patient report wrong by intrinsic perversion: is that the difficulties are own stuff on which to report. The approach that we have proposed, in the end, does not constitute more than an attempt to put at the disposal of the patient the same resources that science uses to deal with the same problem: of lack of quality of managed information. In the words of a researcher in this field, the majority of resources
methodological study of pain are nothing more than means to help the patient to report. (23)
As you can see, it is difficult to assess the pain. Easier to evaluate elements are the physiological responses, which are determined by Catecholamines and cortisol, and that can be changed in up to 20% in response to pain.
The parameters of this response are:
· Heart rate, breathing rate, and blood pressure
· Oxygen consumption
· The mean airway pressure
· Muscle tone
· Intracerebral pressure
· Autonomic changes, such as Mydriasis, sweating, redness or pallor, which may be confused with other causes.
· Behavioural changes; facial changes are those who have less variation between different observers: gestures, tighten eyelids, nostrils open, the sulcus deepening nasolabial, protrusion of the tongue and Chin trembling.
· Also describes bodily movements, as the thumb included, squirm, hits head, shaking legs and back arched.
There are biochemical changes: increase in catecholamines, cortisol, glucagon, the growth hormone, antidiuretic hormone, Renin and angiotensin, and decrease of insulin; in other words, there is a tendency to hyperglycemia.
Although these responses to pain can be assessed, is accepted today the application of scales is better, and easier application to the measurement of all the above elements.
There are multiple scales of pain. The scale that today is used for the treatment of pain is the Visual analog scale of pain (EVA) for adults and children older than 5 years, is a numerical scale graduated from 0 to 10, in which the degree of their pain must be located.
Children under five-year-old uses a scale with faces with different expressions, without numbers. There is the scale of the red, where they are asked to locate the maximum pain they feel.
The EVA is the most widely used and which has had better results after its validation(31).