Inflammation is a local defense mechanism, exclusive of damaged mesenchymal tissues (connective tissue, bone and cartilaginous tissue, blood and lymphatic vessels, and tissue).

It is the local response of the damaged vascularized tissue, characterized by alterations of the vascular system, the liquid and cellular components, also by adaptations of the neighboring connective tissue.

There are some basic phenomena common to any type of inflammation and no matter what the inflammatory agent.

Although these phenomena are divided into five phases they all happen as a single, joint process, which makes inflammation a dynamic process.

Check out what these stages are and what happens most important in each one of them:

• Irritative phase: Morphological and functional modifications of the damaged tissues occur that promote the release of chemical mediators, which will trigger the other inflammatory phases.
• Vascular phase: hemodynamic changes of the circulation and vascular permeability at the site of the aggression.
• Exudative phase: This phase is characteristic of the inflammatory process, and is formed by the cellular and plasma exudates (migration of fluids and cells to the inflammatory focus) from increased vascular permeability.
• Degenerative-necrotic phase: composed of cells with reversible or non-reversible degenerative changes (in this case, originating a necrotic material), derived from the direct action of the aggressor agent or from the functional and anatomical modifications consequent to the previous three phases.
• Productive-reparative phase: increase in the quantity of the tissue elements – mainly cells, result of the previous phases. The objective is to destroy the aggressor agent and repair the battered tissue.

Clinical Manifestations

There are also five classic signs of the inflammatory process, called Flogistic or Cardinal Signs.

They are: edema, heat, redness, pain and loss of function.

Edema is caused mainly by the exudative and productive-reparative phase, because of the increase of liquid and of cells.

The heat comes from the vascular phase, where there is arterial hyperemia (which is the increase of the blood volume in the local) and, consequently, increase of the local temperature.

Redness is redness, which also results from hyperemia.

Pain is caused by more complex mechanisms including compression of local nerve fibers due to edema, direct aggression to nerve fibers and pharmacological action on nerve endings. It involves at least three phases of inflammation (irritative, vascular and exudative).

Finally, loss of function is due to edema (especially in joints, preventing movement) and pain, which hamper local activities.

Nursing Care with the presence of Cardinal Sign

Health-care-related infections are considered preventable by simple measures, with proper hand washing (considered the most efficient measure of prevention) before and after all procedures.

They are the hands that carry the largest number of microorganisms to patients, through direct contact, procedures or the handling of objects. Employee training can improve the knowledge of techniques, increase the quality of care provided to the patient, and decrease the rate of infections related to peripheral or central catheters.

The catheter may be colonized by microorganisms on its external surface, by the subcutaneous tunnel of the surrounding skin or by the microbiota itself, by the hands of contaminated professionals and antiseptics, as the higher the number of bacteria, the greater the likelihood of infection .

There are important risk factors associated with the use of intravascular catheters, which may be related to the host such as: primary diagnosis (baseline disease), comorbidities, antibiotic therapy (dose and duration), use of immunosuppressants and length of stay. And related to the catheter: the type of catheter implanted, technique of insertion of the catheter, length of stay, place of insertion and care with the catheter (with the dressing).

In the presence of a suspicion of infection related to a peripheral or central catheter, the tip of the catheter should be removed, upon request of a medical prescription (when polyurethane, teflon or silicone, which are more recommended because they are thrombogenic materials) and request order to examine catheter tip cultures and refer them to the laboratory.

It can be done through the exudate with staining by the Gram method and submitted to culture, if there are phlogistic signs at the insertion of the catheter.

Performing a dressing with aseptic technique in place removed the catheter in order to prevent the proliferation of bacterial infection in other locations.