A nurse is assessing a client prior to administration of atenolol and finds that the client's apical heart rate is 61/min.
Which of the following actions should the nurse take?

Choice A rationale

Cromolyn is a mast cell stabilizer that works by inhibiting the release of inflammatory mediators like histamine from mast cells. This prophylactic action requires consistent, daily use to build up therapeutic levels and prevent the initiation of the asthmatic response, rather than acting as a rescue medication during an acute attack.

Choice B rationale

Using cromolyn as soon as one feels like wheezing is incorrect because cromolyn is not a bronchodilator and does not provide immediate relief for acute bronchospasm. Its mechanism of action involves stabilizing mast cells, which prevents the degranulation and release of inflammatory mediators, thus preventing symptoms from occurring.

Choice C rationale

Expecting to feel better in a week is an inappropriate timeframe for assessing cromolyn's efficacy. The full prophylactic benefits of cromolyn may take several weeks of consistent use to become apparent. Patients should be educated on the preventative nature and delayed onset of action.

Choice D rationale

While cromolyn can be used prophylactically before exercise, using it 2 hours before playing softball is not the recommended timing. For exercise-induced bronchospasm, cromolyn is typically administered 15 to 30 minutes prior to the activity to allow for adequate absorption and mast cell stabilization before exertion.

• conditions. The client has dyspnea, tachycardia, and low oxygen saturation, suggesting acute illness or cardiovascular instability.
• Bumetanide, a loop diuretic, is contraindicated here as it may worsen hypovolemia and electrolyte imbalance. The client’s blood pressure is high but he is already showing signs of dehydration and electrolyte abnormalities (hypokalemia). Diuretics may exacerbate hypokalemia and hypotension later.
• Labetalol is anticipated for managing the acute hypertension (BP 160/98 mm Hg), especially with the client’s tachycardia and hypertensive urgency signs. It acts by blocking alpha and beta receptors to lower blood pressure safely.
• Oxygen is anticipated because the client’s oxygen saturation is 92% on room air with dyspnea and tachypnea; supplemental oxygen will improve tissue oxygenation and reduce hypoxia.
• Midodrine is contraindicated because it raises blood pressure via alpha-1 agonism; given the client’s elevated BP, it would worsen hypertension and increase cardiovascular risk.
• Calcium gluconate is contraindicated because the client’s calcium is within normal limits (10.3 mg/dL) and giving calcium unnecessarily can cause hypercalcemia or arrhythmias.
• Potassium supplementation is anticipated as the client has hypokalemia (2.8 mEq/L) on Day 2, which can cause arrhythmias and muscle weakness, requiring prompt correction.