The nurse provides care for a client diagnosed with pulmonary emphysema. The nurse observes the following: respiratory rate 20 breaths/minute, use of intercostal muscles, and decreased mental alertness. Which is the best explanation for these observations?

Choice A reason: Decrease in sympathetic nervous system outflow is the best explanation because it is a condition that affects the regulation of blood pressure, heart rate, and skin temperature. The sympathetic nervous system is a part of the autonomic nervous system, which is the part of the nervous system that controls the involuntary functions of the body, such as breathing, digestion, and circulation. The sympathetic nervous system is responsible for the fight-or-flight response, which prepares the body for action or danger, by increasing the blood pressure, heart rate, and skin temperature. The sympathetic nervous system is composed of nerve fibers that originate from the thoracic and lumbar regions of the spinal cord, which are the middle and lower parts of the spinal cord. A complete spinal cord injury at the C3 to C4 level is a condition where the spinal cord is severed or damaged at the neck, which interrupts the communication between the brain and the rest of the body. A complete spinal cord injury at the C3 to C4 level can cause the loss of sympathetic nervous system outflow, which means that the nerve impulses that normally stimulate the blood vessels, the heart, and the sweat glands are reduced or absent. This can result in hypotension, which is a low blood pressure, bradycardia, which is a slow heart rate, and warm and dry skin, which are the observations noted in the client.

Choice B reason: Decreased fluid volume in the intravascular space is not the best explanation because it is a condition that affects the amount of fluid in the blood vessels, which can be caused by various factors, such as dehydration, bleeding, or vomiting. Decreased fluid volume in the intravascular space can cause hypotension, which is a low blood pressure, but it can also cause tachycardia, which is a fast heart rate, and cool and clammy skin, which are not the observations noted in the client.

Choice C reason: The effects of opiate medication administration is not the best explanation because it is a condition that affects the pain perception and the central nervous system, which can be caused by various types of medications, such as morphine, codeine, or oxycodone. The effects of opiate medication administration can cause hypotension, which is a low blood pressure, and bradycardia, which is a slow heart rate, but it can also cause respiratory depression, which is a slow and shallow breathing, and miosis, which is a constriction of the pupils, which are not the observations noted in the client.

Choice D reason: Onset of acute systemic bacterial infection is not the best explanation because it is a condition that affects the immune system and the whole body, which can be caused by various types of bacteria, such as staphylococcus, streptococcus, or salmonella. Onset of acute systemic bacterial infection can cause hypotension, which is a low blood pressure, but it can also cause fever, which is a high body temperature, and chills, which are sensations of coldness and shivering, which are not the observations noted in the client.

Choice A reason: Prostaglandins are inflammatory mediators that are derived from arachidonic acid. They are involved in both the early and late phases of type 1 hypersensitivity response, but they do not cause immediate bronchoconstriction and vasodilation. They mainly cause pain, fever, and inflammation.

Choice B reason: Histamine is an inflammatory mediator that is stored in mast cells and basophils. It is released during the early phase of type 1 hypersensitivity response, which occurs within minutes of exposure to an allergen. It causes immediate bronchoconstriction and vasodilation, as well as increased vascular permeability, mucus secretion, and itching.

Choice C reason: Leukotrienes are inflammatory mediators that are derived from arachidonic acid. They are involved in the late phase of type 1 hypersensitivity response, which occurs several hours after exposure to an allergen. They cause sustained bronchoconstriction and inflammation, as well as increased mucus production and airway edema.

Choice D reason: Bradykinin is an inflammatory mediator that is formed from plasma proteins. It is not directly involved in type 1 hypersensitivity response, but it may be activated by the complement system, which is part of the innate immune system. It causes vasodilation, increased vascular permeability, and pain.