What is an example of a client's primary defense to infection?

Choice A reason: A susceptible host is not an infectious disease, but a factor that influences the transmission of an infectious disease. A susceptible host is a person who is vulnerable to infection due to factors such as age, health status, immunization, or genetic predisposition. A susceptible host may become infected by a communicable disease, but it is not the disease itself.

Choice B reason: A communicable disease is an infectious disease that can be transmitted directly from one person to another. A communicable disease is caused by a pathogen, such as a virus, bacterium, fungus, or parasite, that can spread through contact, droplet, airborne, vector, or vehicle transmission. Examples of communicable diseases are influenza, tuberculosis, measles, malaria, and HIV/AIDS.

Choice C reason: A portal of entry to a host is not an infectious disease, but a factor that influences the transmission of an infectious disease. A portal of entry to a host is a route through which a pathogen can enter the body of a susceptible host and cause infection. A portal of entry to a host may be a break in the skin, a mucous membrane, or a body opening, such as the mouth, nose, eyes, or genitals. A portal of entry to a host may facilitate the transmission of a communicable disease, but it is not the disease itself.

Choice D reason: A portal of exit from the reservoir is not an infectious disease, but a factor that influences the transmission of an infectious disease. A portal of exit from the reservoir is a route through which a pathogen can leave the body of an infected person or animal and reach another susceptible host. A portal of exit from the reservoir may be a body fluid, such as blood, saliva, urine, or feces, or a body part, such as the skin, hair, or nails. A portal of exit from the reservoir may enable the transmission of a communicable disease, but it is not the disease itself.

Choice A reason: A bone fragment has injured the nerve supply in the area is not the best response by the nurse. This may be a possible complication of a fracture, but it does not explain the mechanism of compartment syndrome. Compartment syndrome is a condition where the pressure within a closed space (such as a muscle compartment) exceeds the perfusion pressure and causes ischemia and necrosis of the tissues. A bone fragment may damage the nerve, but it does not cause increased pressure in the compartment.

Choice B reason: An injured artery causes impaired arterial perfusion through the compartment is not the best response by the nurse. This may be a possible cause of compartment syndrome, but it is not the most common one. Compartment syndrome is more often caused by venous obstruction than arterial obstruction. An injured artery may reduce the blood flow to the compartment, but it does not cause increased pressure in the compartment.

Choice C reason: Bleeding and swelling cause increased pressure in an area that cannot expand is the best response by the nurse. This is the most common cause of compartment syndrome and explains the pathophysiology of the condition. Bleeding and swelling are the result of inflammation and tissue injury that occur after a fracture. They increase the volume of fluid in the compartment, which cannot expand due to the rigid fascia that surrounds it. This leads to increased pressure in the compartment, which compresses the blood vessels, nerves, and muscles and causes ischemia and necrosis of the tissues.

Choice D reason: The fascia expands with injury, causing pressure on underlying nerves and muscles is not the best response by the nurse. This is not a correct statement, as the fascia does not expand with injury. The fascia is a tough connective tissue that encloses the muscle compartments and limits their expansion. The fascia is part of the problem, not the cause, of compartment syndrome. The fascia prevents the compartment from accommodating the increased volume of fluid and causes increased pressure in the compartment.