A client develops edema of the left arm and hand following a left radical mastectomy. The nurse explains the cause of the edema. Which explanation is correct?

Choice A reason: Lymph structures were removed and fluid cannot move out of the area easily is the correct explanation because a radical mastectomy involves the removal of the breast, the underlying chest muscles, and the lymph nodes in the axilla. The lymph nodes are part of the lymphatic system, which is responsible for draining excess fluid from the tissues and returning it to the bloodstream. When the lymph nodes are removed, the fluid cannot be drained properly and accumulates in the affected arm and hand, causing edema.

Choice B reason: There is still too much swelling in the area of the surgery and fluid is accumulating is not the correct explanation because it does not address the underlying cause of the edema. Swelling is a normal response to surgery, but it usually subsides within a few days or weeks. The edema caused by lymph node removal is chronic and persistent, and it does not improve with time.

Choice C reason: The veins were removed from the axilla during surgery and there is poor circulation now is not the correct explanation because it is not true. The veins are not removed during a radical mastectomy, only the lymph nodes are. The veins are part of the circulatory system, which carries blood throughout the body. The blood flow to the arm and hand is not affected by the surgery, unless there is a complication such as a blood clot or an infection.

Choice D reason: You will need to wear a compression bandage to help fluids move from the area is not the correct explanation because it is a treatment, not a cause. A compression bandage is a type of elastic bandage that applies pressure to the arm and hand, which helps to reduce the swelling and prevent further fluid accumulation. However, it does not address the root cause of the edema, which is the removal of the lymph nodes.

Choice A reason: Ischemia of the motor and sensory neurons in the brain is not the cause of multiple sclerosis, but a possible consequence of it. Ischemia is a lack of blood supply to the tissues, which may result from inflammation, thrombosis, or embolism. It may cause neuronal death, stroke, or dementia.

Choice B reason: Damage and scarring of the white matter in the brain is the best description of the cause of multiple sclerosis. Multiple sclerosis is an autoimmune disorder that causes the immune system to attack the myelin sheath, which is a protective layer that covers the nerve fibers. The damage and scarring of the myelin sheath, also called demyelination, disrupts the transmission of nerve impulses and causes various neurological symptoms.

Choice C reason: Infection of the parietal and temporal lobes of the brain is not the cause of multiple sclerosis, but a rare complication of it. Infection of the brain, also called encephalitis, may occur due to viral, bacterial, or fungal agents. It may cause fever, headache, confusion, seizures, or coma.

Choice D reason: Increased amounts of epinephrine and acetylcholine in the brain are not the cause of multiple sclerosis, but a possible effect of it. Epinephrine and acetylcholine are neurotransmitters that regulate the sympathetic and parasympathetic nervous systems, respectively. They may be affected by the demyelination of the nerve fibers, which may alter the autonomic functions such as heart rate, blood pressure, digestion, or bladder control.