The nurse is caring for a patient with a lower respiratory tract infection. When planning a focused respiratory assessment, the nurse should know that this type of infection most often causes what?

Correct Answer: A

Rationale: Step 1: Lower respiratory tract infection affects the lungs where gas exchange occurs. Step 2: Infections can lead to inflammation and fluid buildup in the lungs. Step 3: This impairs the exchange of oxygen and carbon dioxide. Step 4: Impaired gas exchange can lead to hypoxemia and respiratory distress. Step 5: Therefore, the correct answer is A: Impaired gas exchange. Other choices are incorrect because they do not directly relate to the physiological consequences of a lower respiratory tract infection.

Correct Answer: B

Rationale: The correct answer is B (45 mm Hg) because the partial pressure of carbon dioxide in the interstitial space of peripheral tissues is around 40-45 mm Hg. This value is higher than in the arterial blood (around 40 mm Hg) due to the production of CO2 by tissues. Choice A (35 mm Hg) is too low for interstitial CO2 levels. Choice C (55 mm Hg) and D (70 mm Hg) are too high and not consistent with normal physiological values. Overall, the correct answer aligns with the typical range of interstitial CO2 pressure in peripheral tissues.

Correct Answer: A

Rationale: Step 1: Increased PO2 leads to higher oxygen levels in blood. Step 2: Higher PO2 causes hemoglobin to become fully saturated with oxygen. Step 3: Fully saturated hemoglobin stores more oxygen. Step 4: Therefore, as PO2 increases, saturation goes up and hemoglobin stores more oxygen. Other choices are incorrect because they do not align with the relationship between PO2, hemoglobin saturation, and oxygen storage in the blood.

Correct Answer: A

Rationale: The correct answer is A because at birth, when an infant takes their first breaths, blood flow to the lungs increases due to the expansion of the pulmonary vasculature. This allows for proper oxygenation of the blood. Choice B is incorrect as the resistance in the pulmonary arteries decreases to accommodate the increased blood flow to the lungs. Choice C is incorrect as changes in blood flow do cause the foramen ovale to close, ensuring proper circulation. Choice D is incorrect as air entering the alveoli is essential for oxygen exchange to occur in the lungs.

Correct Answer: A

Rationale: The correct answer is A: Electrocardiogram (ECG or EKG). An ECG is commonly used to assess heart function in heart failure because it provides information on the heart's electrical activity, rhythm, and any abnormalities. It can detect conditions such as arrhythmias, ischemia, and previous heart attacks. Other choices are incorrect: B (MRI) is more for imaging the structure of the heart, C (Colonoscopy) is for examining the colon, and D (Blood glucose test) is for measuring blood sugar levels, not heart function.