A 65-year-old male patient was admitted to a medical-surgical unit 72 hours ago with pyloric stenosis; a nasogastric tube was inserted upon admission and has been on low intermittent suction since then. The nurse taking care of the patient notices that his potassium is very low and becomes concerned that the patient may be at risk for:

Correct Answer: C

Rationale: Probably the most common cause of metabolic alkalosis is vomiting or gastric suction with loss of hydrogen and chloride ions. The disorder also occurs in pyloric stenosis in which only gastric fluid is lost. Vomiting, gastric suction, and pyloric stenosis all remove potassium and can cause hypokalemia.

Correct Answer: C

Rationale: Inelastic skin turgor is a normal part of aging. Dehydration, not overhydration, causes inelastic skin with tenting. Overhydration, not dehydration, causes the skin to appear edematous and spongy. Normal skin turgor is dry and firm.

Correct Answer: B

Rationale: An air emboli is more often associated with central vein access. Usually only relatively large volumes of air administered rapidly are dangerous. It is more often a concern when air enters a central venous access line.

Correct Answer: A

Rationale: To gauge a patient's magnesium status, the nurse should check deep tendon reflexes. If the reflex is absent, this may indicate high serum magnesium.

Correct Answer: C

Rationale: Fluid loss from the extracellular compartment can be caused by abdominal surgery.

Correct Answer: D

Rationale: Although changes in all these findings are seen in hyperkalemia, ECG changes can indicate potentially lethal arrhythmias such as ventricular fibrillation. It wouldn't be appropriate to assess the patient's neuromuscular function, bowel sounds, or respiratory rate for effects of hyperkalemia.

Correct Answer: D

Rationale: When PaCO2 chronically exceeds 50 mm Hg, it creates insensitivity to CO2 in the respiratory medulla, and the use of oxygen may result in the patient developing carbon dioxide narcosis and hypoxemia.

Correct Answer: B

Rationale: Osmosis is the movement of fluid from a region of low solute concentration to a region of high solute concentration across a semipermeable membrane. The number of dissolved particles contained in a unit of fluid determines the osmolality of a solution, which influences the movement of fluid between the fluid compartments. Giving a patient who has a low blood pressure a hypertonic solution will increase the number of dissolved particles in the blood, creating pressure for fluids in the tissues to shift into the capillaries and increase the blood volume. Option A is incorrect; hydrostatic pressure refers to changes in water or volume related to water pressure. Option C is incorrect; diffusion is the movement of solutes from an area of greater concentration to lesser concentration. The solutes in an intact vascular system are unable to move, so diffusion should not normally take place. Option D is incorrect; active transport is the movement of molecules against the concentration gradient and requires ATP as an energy source. This process typically takes place at the cellular level and is not involved in vascular volume changes.

Correct Answer: C

Rationale: Prior to initiating an IV, the nurse should verify the physician's order for IV therapy.