A nurse is obtaining informed consent from a client who is preoperative. Which of the following actions should the nurse take? (Select all that apply.)

A. Metabolic acidosis is characterized by a decrease in bicarbonate or an increase in acids, which can be caused by conditions like kidney failure or diabetic ketoacidosis, but it is not typically associated with numbness and tingling.
B. Respiratory alkalosis is characterized by a high pH (>7.45) and a decreased PaCO2 (<35 mm Hg). It typically results from hyperventilation, which leads to excessive elimination of CO2 and subsequent alkalosis. This condition is less likely to occur in gastroenteritis unless there are other complicating factors such as anxiety or pain causing increased respiratory rate.
C. In the context of gastroenteritis, where there may be a loss of stomach acids through vomiting or diarrhea, the most likely acid-base imbalance would be metabolic alkalosis.
D. Respiratory acidosis is characterized by a low pH and an elevated PaCO2 (>45 mm Hg). It results from hypoventilation, leading to retention of CO2 and subsequent acidosis. Respiratory acidosis would not typically present with numbness and tingling in the extremities in the context of gastroenteritis.

A. Postoperative ileus and significant drainage via an NG tube are more likely to lead to electrolyte losses rather than elevated levels. Elevated magnesium levels are less common and typically associated with conditions such as renal failure or excessive magnesium intake.
B. Calcium levels can be affected by gastrointestinal losses, including drainage via an NG tube. Significant fluid loss can lead to hemoconcentration, potentially causing a relative increase in calcium levels initially. However, prolonged fluid loss can lead to overall depletion of electrolytes, including calcium.
C. When fluids are lost through the NG tube, potassium, which is an intracellular electrolyte, can be lost in large amounts. Prolonged drainage can lead to hypokalemia (decreased potassium levels), which can result in muscle weakness, cardiac dysrhythmias, and other serious complications.
D. Elevated sodium levels (hypernatremia) are more commonly associated with dehydration or excessive sodium intake rather than drainage via an NG tube. In this scenario, sodium levels are less likely to be affected compared to potassium.