Nurse Margie just administered an ACE inhibitor to her client. Before ambulating the client for the first time after administration, the nurse should monitor for:
A. Hypokalemia
B. Irregular heartbeat
C. Edema
D. Hypotension
Correct Answer: D. Hypotension
ACE inhibitors prevent vasoconstriction and lower blood pressure, placing the client at greater risk for postural (orthostatic) hypotension. Angiotensin II acts as a potent vasoconstrictor that, when inhibited, can reduce blood pressure by dilating vessels and decreasing aldosterone secretion.
Option A: ACE inhibitors reduce potassium excretion placing the client at risk for hyperkalemia. Hyperkalemia from ACE inhibitors is a direct result of the mechanism of action. The blockade of angiotensin II prevents the downstream secretion of aldosterone. Aldosterone causes reabsorption of sodium and, subsequently, water. Consequently, protons and potassium get secreted into the urine. Without the secretion of potassium through aldosterone, potassium can easily increase in patients on ACE inhibitors. Comorbidities that decrease kidney function or medications that cause potassium retention increases the risk of hyperkalemia.
Option B: ACE inhibitors do not affect heart rate. ACE inhibitors can be used for the treatment of hypertension (HTN) either alone or in conjunction with other antihypertensives in adults or children greater than six years old. Hypertension guidelines recommend the initiation of ACE inhibitors for the management of HTN to lower blood pressure (BP).
Option C: ACE inhibitors promote sodium excretion thereby decreasing edema. Angioedema is a rare but potentially life-threatening side effect of ACE inhibitor use. The side effect is a swelling of the face, lips, and upper airway in an episodic nature. The inflammation creates difficulty in the patient’s ability to maintain an airway; therefore, endotracheal intubation is necessary to secure the airway. The mechanism of angioedema is thought to be through an extensive accumulation of bradykinins in select individuals.