The most common component of renal calculi is:

A. In diabetic ketoacidosis (DKA), serum bicarbonate is typically decreased, not increased. The decrease is due to metabolic acidosis resulting from the accumulation of ketones.

B. Serum potassium is often elevated in DKA initially due to the shift of potassium from inside the cells to the bloodstream as a result of acidosis. However, potassium levels may drop with treatment, especially with insulin administration, which drives potassium back into cells.

C. Urine pH in DKA is often acidic due to the presence of ketones, which are acidic byproducts of fat metabolism. A urine pH of 4.0 indicates aciduria, which is consistent with ketoacidosis.

D. Serum pH in DKA is typically low (below 7.35), indicating acidosis. A serum pH of 7.5 would suggest alkalosis, which is not typical of DKA.

A. While status asthmaticus is a severe, life-threatening asthma exacerbation, the first step is to stabilize the patient by improving oxygenation and relieving airway obstruction, not immediately calling 911 unless the situation worsens.

B. Intubation is not the first step unless the patient's respiratory status continues to deteriorate despite initial interventions. The focus should be on improving oxygenation and managing the airway.

C. Establishing IV access and administering emergency medications, such as corticosteroids or bronchodilators, may be necessary, but the first priority is to improve the patient's breathing and oxygenation.

D. Placing the patient in a high Fowler's position helps to open the airways and facilitate breathing. Starting oxygen therapy is essential to support oxygenation in a patient with labored breathing. This should be the first intervention.