In this section of the NCLEX-RN examination, you will be expected to demonstrate your knowledge and skills of pathophysiology in order to:
- Identify pathophysiology related to an acute or chronic condition (e.g., signs and symptoms)
- Understand general principles of pathophysiology (e.g., injury and repair, immunity, cellular structure)
The pathophysiology of many acute, chronic and emergency disorders and conditions, including etiologies, risk factors, signs, symptoms, diagnostic findings, complications, and expected outcomes were discussed throughout this NCLEX RN review.
Some of the general principles of pathophysiology include the stages of infection, the phases of the inflammatory process, the stages of wound healing, immunological bodily responses, and the role of cellular structures.
The stages of infection and a brief description of each of these four stages are discussed below:
- The incubation stage: The incubation stage begins with the entry of the pathogen into the host and this stage ends when the signs and symptoms of the infection begin to appear.
- The prodromal stage: The prodromal stage begins with the onset of symptoms and this stage is characterized with the replication and reproduction of the pathogen; and the signs and symptoms of the prodromal stage include generalized malaise, joint and muscular aches and pains, anorexia, and the presence of a headache.
- The illness stage: The illness stage is the period of time that begins with continuation of the signs and symptoms and it continues until the symptoms are no longer as serious as they were before.
- The convalescence stage: The convalescence stage is the period of recovery during which time the symptoms completely disappear. .
The inflammatory process is the naturally occurring protective response of the body to a threat in terms of tissue damage; this process defends the body against harm, it aims to rid the body of damaged tissue and it promotes the restoration of normal tissue.
The five classic signs and symptoms of inflammation are:
- Pain: Pain occurs with the release of chemicals secondary to the damage of cells and tissues
- Redness: Redness results from the vasodilation of blood vessels that occurs in response to the injury.
- Swelling: Swelling occurs as the body's fluids enter the area of the injury and tissue damage.
- Heat and warmth: Heat and warmth occur as the result of the vasodilation and the increased blood flow to the affected area.
- Dysfunction of the area: Local dysfunction occurs as the result of the swelling and pain associated with the inflammatory process.
The four phases of bacterial growth are in this sequential order.
- The lag phase of bacterial growth: The lag phase of bacterial growth consists of the bacteria's slow growth as it adjusts to its new environment in the human body. The rate of biosynthesis is high because the bacteria need these proteins for their future period of rapid growth and replication.
- The lag phase of bacterial growth: The lag phase of bacterial growth, which is sometimes referred to as the exponential phase of bacterial growth, is characterized with a period of rapid and continuous growth until one or more of the nutrients necessary for this rapid growth is no longer available to the pathogen.
- The stationary stage of bacterial growth: The stationary stage of bacterial growth marks the end of the bacteria's growth and metabolic activity because all the nutrients for these activities have been exhausted and depleted.
- The death stage of bacterial growth: This stage is characterized with the end of the bacteria's life because there are no nutrients to sustain it and no metabolic activity.
Similarly, the six stages of a virus growth include:
- The attachment stage: The attachment stage consists of the virus' attachment to a receptor on the host's cellular surface. A limited or low host range in terms of attachment means that some of these attachments are relatively limited and highly specific to only some receptors; and the converse is also true, there are pathogens with a wide host range in terms of attachment which means that the attachments are greater in terms of possibility and not highly specific.
- The penetration stage: The penetration stage is marked with the entry of the virus into the host's cell.
- The uncoating stage: The uncoating stage entails the shedding of the virus coating, or its viral capsid, which now allows the virus to deposit its own nucleic material into the human's host cells.
- The replication stage: The replication stage consists of the duration of time during which the virus is able to replicate and multiple.
- The self-assembly stage: During the self-assembly stage, the virus matures and makes modifications to its proteins.
- The release and lysis stage: During the release and lysis stage the virus is released from the host cells with lysis and the resulting death of the virus.
The phases of the inflammatory process include:
- Tissue injury as the result of the injury
- The release of chemicals, such as kinins, histamine and prostaglandins from the damaged cells and tissues. These chemicals are vasodilators that increase the blood supply to the damaged cells and tissues.
- The natural, defensive movement and migration of leukocytes, including macrophages and neutrophils, to the areas where cellular and tissue damage has occurred
Some professional resources refer to the stages of the inflammatory process as the vascular and cellular response stage, the exudate stage, and the reparative phase of the inflammation process instead of tissue injury phase, the release of chemicals stage and the final stage of the inflammatory process, respectively.
The stages of wound healing are the:
- The homeostasis phase: The homeostasis phase is accompanied with vasoconstriction, thrombin formation, platelet formation, and the formation of a fibrin mesh for healing that begins the healing process.
- The inflammation phase: The inflammation phase, which is also referred to as the lag or exudate phase, is accompanied with pain, swelling , edema, and the beginning of wound debris removal with phagocytosis to prevent infection.
- The proliferative and granulation phase: The proliferative and granulation phase is accompanied with the fibroblastic production of granulation tissue and collagen.
- The maturation phase: The maturation phase of wound healing is characterized with the continued development and maturation of the fragile skin over the wound. This phase can last up to two years during which time the wound remains at risk and vulnerable for injury until full healing and good tensile strength is complete.
Immunological bodily responses are both innate and adaptive. Innate immunity is the natural, intrinsic nonspecific immunity mechanisms that protects the body and resists infection with its physical, cellular, and chemical mechanisms and means. For example, when a pathogen breaks through the skin or mucus membranes, our first lines of defense, chemical cytokines and other antimicrobial substances and phagocytic activity prepare the host cells to prevent the pathogen's entry, colonization, spread and replication.
Adaptive immunity is categorized as active and passive immunity which, simply stated, are the deliberate or undeliberate exposure to a pathogen and the acquisition of antibodies or activated T cells in the body, respectively.
Active immunity occurs as the result of our bodily response to the presence of an antigen, with the development of antibodies. Active immunity can be both natural and artificial. Natural active immunity occurs when the body produces antibodies after the client is infected with a pathogen; and artificial active immunity occurs when the body produces antibodies to an immunization vaccine such as those for pneumonia and a wide variety of childhood infectious diseases.
Passive immunity occurs when an antibody is introduced into the body by either natural or artificial means. Passive natural immunity occurs when the fetus and neonate receive immunity as a natural process through the placenta; and passive artificial immunity occurs when the client receives an injection of immune globulin.
Applying a Knowledge of Nursing Procedures and Psychomotor Skills When Caring for a Client Experiencing a Medical Emergency
Cardiopulmonary arrest is the sudden loss of cardiac function, the cessation of breathing and the client's complete loss of consciousness, as the result of a significant disturbance of the heart' electrical impulses, such as ventricular tachycardia and asystole, as discussed previously in the sections entitled "Hemodynamics: Identifying Cardiac Rhythm Abnormalities" and "Intervening to Improve the Client's Cardiovascular Status".
The immediate treatment for sudden cardiac arrest is cardiopulmonary resuscitation (CPR) and defibrillation, as indicated by the client's condition.
Airway obstructions can be partial or complete. A complete airway obstruction is signalled with the lack of any cough or other noises from the patient. The airway must be opened using the techniques you have learned when you took your Basic Life Support course. Intubation, when necessary, is also done.
A partial airway obstruction can be determined by listening to the patient's cough and other respiratory noises. A cough that is not efficient indicates a more severe airway obstruction than a cough that is effective in terms of clearing the airway of secretions and/or foreign bodies. The patient who is coughing should be encouraged and prompted to continue to cough. Visible foreign bodies that can be removed and should only be removed if there is no chance of pushing the foreign body further into the airway.
The look, listen and feel assessment for breathing to determine whether or not the patient is spontaneously breathing on their own includes looking at the chest to see if it rises and falls, listening for any breath sounds from the nose or mouth, and feeling the chest and upper abdomen to see if there is any movement present. Rescue breathing is done when the patient is not breathing and the airway is open.
Chest compressions are done, as you learned in your Basic Life Support course, on all patients who are unconscious, unresponsive, not breathing and pulse less.
Defibrillation gives an electric shock to the heart. There are standard external defibrillators which are typically found in hospitals and other healthcare facilities and used by nurses, transvenous defibrillators, implantable cardioverter defibrillators, and automated external defibrillators.
Automated external defibrillations are most often found in the community and outside of healthcare facilities. Automated external defibrillations are simple to use and there is no need to be able to recognize cardiac arrhythmias or interpret cardiac rhythm strips. Automated external defibrillations are intended to be used by the general public without any healthcare or nursing knowledge of experience.
The steps for using an automated external defibrillation is turn the machine on, put the pads on the patient's chest as shown on the machine, and then listen to and follow the automated instructions of the automated external defibrillation.
- Alterations in Body Systems
- Fluid and Electrolyte Imbalances
- Illness Management
- Medical Emergencies
- Pathophysiology (Currently here)
- Unexpected Responses to Therapies