A nurse is caring for a client who has acute respiratory failure (ARF). The nurse should monitor the client for which of the following manifestations of this condition? (Select all that apply.)

Choice A: Evaluating chest expansion is the first action that the nurse should take, because it assesses the client's respiratory status and potential for pneumothorax, which is a life-threatening condition that can result from chest trauma. The nurse should compare the movement of both sides of the chest and listen for breath sounds.

Choice B: Checking pupillary response to light is an important action, but not the first one, because it assesses the client's neurological status and potential for brain injury. The nurse should observe the size, shape, and symmetry of the pupils and their reaction to light.

Choice C: Checking the client's response to questions about place and time is another important action, but not the first one, because it assesses the client's level of consciousness and orientation. The nurse should ask the client simple questions such as their name, date, and location.

Choice D: Assessing the capillary refill is a less important action, and not the first one, because it assesses the client's peripheral circulation and tissue perfusion. The nurse should press on the client's nail beds or fingertips and observe how quickly the color returns.

Choice A Reason: This choice is correct because respiratory acidosis is a condition in which the lungs cannot eliminate enough carbon dioxide (CO2) from the blood, resulting in a high level of CO2 (PaCO2) and a low level of pH. A normal PaCO2 range is 35 to 45 mm Hg, so a value of 50 mm Hg indicates respiratory acidosis.

Choice B Reason: This choice is incorrect because HCO3 (bicarbonate) is a base that helps to buffer the excess acid in the blood. In respiratory acidosis, the kidneys try to compensate by retaining more HCO3 and excreting more hydrogen ions. Therefore, a high level of HCO3 (above 26 mEq/L) would indicate a chronic or compensated respiratory acidosis, not an acute or uncompensated one.

Choice C Reason: This choice is incorrect because pH is a measure of the acidity or alkalinity of the blood. A normal pH range is 7.35 to 7.45, so a value of 7.45 indicates a neutral or slightly alkaline blood, not an acidic one. A low pH (below 7.35) would indicate respiratory acidosis.

Choice D Reason: This choice is incorrect because potassium is an electrolyte that helps to regulate the nerve and muscle function, as well as the fluid balance in the body. In respiratory acidosis, the increased hydrogen ions in the blood may shift into the cells in exchange for potassium, resulting in a high level of potassium (hyperkalemia).

Therefore, a low level of potassium (below 3.5 mEq/L) would indicate hypokalemia, not respiratory acidosis.