Final answer:
The serum potassium level of 3.1 mEq/L is the most concerning when preparing to administer digoxin to a patient with atrial fibrillation, as it indicates hypokalemia, which can increase the risk of digoxin toxicity and consequent arrhythmias. This value should be corrected before administration of digoxin.
Step-by-step explanation:
The question is asking which laboratory value should be of the highest concern when administering digoxin to a patient with atrial fibrillation. Among the options provided, the serum potassium level of 3.1 mEq/L should be the highest concern for the nurse. Digoxin has a narrow therapeutic window and its effects are heavily influenced by potassium levels. Hypokalemia (low potassium levels) can increase the risk of digoxin toxicity, which can lead to life-threatening arrhythmias.
It is important to note that the normal range of serum potassium is typically between 3.5 and 5.0 mEq/L. Therefore, a value of 3.1 mEq/L indicates hypokalemia and requires immediate attention. The nurse should report this value to the physician and follow orders that may include potassium supplementation to correct the hypokalemia before safely administering digoxin.
This is more concerning than the other values provided since elevated serum creatinine may indicate impaired renal function and could affect digoxin clearance. A hemoglobin level of 9.4 g/dL, though low, would not directly affect digoxin administration. An elevated B-type natriuretic peptide level suggests heart failure but is not as immediately relevant to the administration of digoxin as the serum potassium level.