A nurse is assisting with the care of a school-age child who has respiratory failure due to pneumonia. Which of the following positions should the nurse encourage to allow maximal lung expansion?

Choice A reason: Tachycardia is not an adverse effect of oxygen therapy. Tachycardia is a condition where the heart rate is faster than normal, usually above 100 beats per minute. Tachycardia can be caused by various factors, such as fever, infection, pain, or anxiety. Tachycardia can also be a sign of hypoxemia, which is a low level of oxygen in the blood, and may indicate the need for oxygen therapy.

Choice B reason: Cracks in oral mucous membranes are an adverse effect of oxygen therapy. Cracks in oral mucous membranes are a sign of dryness and irritation caused by the oxygen flow. Oxygen therapy can reduce the natural moisture and lubrication of the mouth and nose, leading to discomfort and increased risk of infection. To prevent or treat this problem, the nurse should provide the client with humidified oxygen, oral care, and hydration.

Choice C reason: Excessive pulmonary secretions are not an adverse effect of oxygen therapy. Excessive pulmonary secretions are a sign of inflammation and infection in the lungs, which can impair gas exchange and cause coughing, wheezing, and dyspnea. Excessive pulmonary secretions can be a symptom of pneumonia, which is a common cause of respiratory failure and may require oxygen therapy.

Choice D reason: Poor skin turgor is not an adverse effect of oxygen therapy. Poor skin turgor is a sign of dehydration, which is a loss of fluid from the body. Dehydration can be caused by various factors, such as vomiting, diarrhea, fever, or inadequate intake. Dehydration can affect the blood volume and pressure, and may worsen the oxygen delivery to the tissues. To prevent or treat this problem, the nurse should monitor the client's fluid balance and provide adequate hydration.

Choice A reason: A heart murmur is a common finding in clients who have mitral valve stenosis. It is a sound produced by turbulent blood flow through the narrowed valve. The murmur is usually heard as a low-pitched rumbling sound during diastole.

Choice B reason: Bradycardia is not a typical finding in clients who have mitral valve stenosis. Bradycardia is a slow heart rate, usually below 60 beats per minute. Mitral valve stenosis can cause tachycardia, which is a fast heart rate, due to increased cardiac workload and reduced cardiac output.

Choice C reason: Clubbing of the fingers is not a sign of mitral valve stenosis. Clubbing is a deformity of the fingertips and nails that occurs due to chronic hypoxia. Mitral valve stenosis can cause pulmonary hypertension and pulmonary edema, which can impair gas exchange, but not to the extent of causing clubbing.

Choice D reason: Barrel chest is not a sign of mitral valve stenosis. Barrel chest is a condition where the chest is enlarged and rounded due to chronic lung disease. Mitral valve stenosis can affect the lungs by increasing the pressure in the pulmonary circulation, but it does not cause structural changes in the chest wall.