Webmaster's note: This site is designed to display appropriately with a screen resolution of 640X480 pixels, 800X600 pixels, or 1024X768 pixels. Please report any broken links, or display problems, to the webmaster using the "contact page." If You experience any problems with the navigation links below, please use our Site Map to navigate the site.
|
Allergic Reactions
|
In order to have a clear-cut understanding of our "PURPOSE" when we treat patients experiencing allergic reactions, we need a clear-cut understanding of some of the "basics." "Basics," as simple as good patient assessment, and "basics" as complex as the body's 'normal' reaction (or abnormal [allergic] reaction) to an allergen.
We start by 'understanding' that it is NOT the allergen (directly) that causes an Allergic Reaction, but the body's response to the allergen, and it is that 'response' that we must affect, if, indeed, it is out of control. We will be able to determine if the response is out of control by way of a thorough patient assessment. There are different levels of local and systemic response to allergens. Essentially, a local response is to be considered less threatening than a systemic one. The 'allergens' may be ingested, inhaled, injected, or absorbed, and may be 'found' in insect bites or stings, medications, plants, food, or chemicals. Because we will be 'treating' the response (and not the allergen) is not essential that we know "the details" of what caused the allergic reaction, if that effort would unnecessarily delay appropriate patent care. The time devoted to the history-taking aspect of patient assessment should be limited to "knowing what happened" in general. We must concentrate on the patient's reaction to the allergen AND how that reaction is changing as time passes. Knowing the administration route, for example, will give us some insight into how rapidly we can expect the allergen to illicit a response from the immune system. For example, an initial response to a bee-sting might include a swelling (hive) at the site of the envenomation. As the venom is conducted through the circulatory system, the body's response to this 'invader,' may change. Hives may start to appear systemically, fluid may start to accumulate in the affected limb (or near the site of the bee-sting.) As the allergen moves into central circulation, the response may become even more systemic, wheezing may develop as fluid accumulates in the tissues surrounding the trachea. The reaction has escalated from a simple allergic reaction to an anaphylactic reaction, and has happened in a relatively short period of time, because the administration route was an "injection." Left unchecked, the body will become 'shocky,' and anaphylactic shock and death may result.
We are going to 'take a lesson' from the body, to help us affect this 'out-of-control' process.
If you recall, way back in the section on the Endocrine System on the page entitled, "The Human Body," we talked about the 'fight or flight' response. For your convenience, we reproduced part of that article here:
In an effort to help you remember the changes in the body that take place as a result of the "fight or flight" syndrome, we would like you to consider what happens when you are suddenly placed in a stressful environment.
Imagine you're driving down a country back road, within the speed limit, enjoying the scenery, relatively relaxed. Suddenly, as you crest a hill, a car enters the roadway from an intersecting road, and you are forced to swerve into the oncoming lane of traffic, where you narrowly avoid collision with an oncoming vehicle, by again swerving back into the proper lane. As all of this transpires, you feel a rush of warmth spread throughout your body. This is one of the affects of adrenaline (epinephrine) and a marker of the "fight or flight" syndrome. What we are going to do is consider each major area in the body, determine whether its involvement is essential for the successful resolution of the problem, and how the human body and some of its systems would have to be altered in order to achieve the desired outcome.
Let's start at the top and work our way down.
Webmaster's Note: For the sake of time and space, we have deleted all but the sub-sections on the respiratory system and integumentary system, from the original explanation.
The respiratory system. Key player? You bet. The entire respiratory tract is dilated, allowing for more efficient exchange of Oxygen and Carbon Dioxide, and the respiratory rate is increased in order to supply the increased metabolism.
The musculoskeletal and the integumentary systems are going to have a 'mixed' response. Large blood vessels, that supply large muscles (strength preparedness) will dilate. Smaller blood vessels (near the surface of the skin) will constrict, conserving body heat for the increased metabolism in other areas. This will impart a pale look to the person involved in this situation.
The "out-of-control" process described above (where anaphylactic shock and death may result) is threatening the respiratory system. If we were to inject an adrenaline-like substance into the circulatory system, we would be able to minimize the respiratory insult, by dilating the respiratory tract. But to 'inject' this substance directly into the circulatory system, would have a life-threatening effect on the cardiovascular system. What we need to do is to administer this adrenaline-like substance in a way that allows the substance to be "taken-up" by the body in a more controlled (slower) fashion. This would include intramuscular or subcutaneous injection.
It is for this reason that some patients (those that have a history of significant previous allergic reaction) carry an EPI-pen. The EPI-pen administers a standardized dose of epinephrine (the "adrenalin-like" substance) in a controlled fashion and helps reverse the respiratory system insult.
As has been the case throughout this site, it is not our purpose to reiterate the information that you will get in an EMT course, but rather to augment that information. For that reason, we do not consider it appropriate to list the protocols that define the 'proper' use of the epi-pen. They may differ from area to area. We will, however, remind the reader that, they (the healthcare providers) are not "administering" the drug to this patient. They are "helping" the patient 'self-administer' to whatever extent that 'help' is needed, and are encouraged to document all the events surrounding this incident, including those events involved in the self-administration of the epi-pen.
