Final answer:
Aminophylline is used for the short-term control of reversible airway obstruction with side effects like tachycardia, nervousness, restlessness, and nausea being significant in clients with cardiac impairment.
Step-by-step explanation:
Aminophylline is used for short-term control of reversible airway obstruction such as in acute asthma exacerbations. When monitoring clients with cardiac impairment, side effects such as tachycardia, nervousness, restlessness, and nausea should be carefully observed. Due to the pharmacological actions of aminophylline to stimulate cardiac muscle and increase the force of contractions, as well as its capacity to inhibit reuptake of neurotransmitters like epinephrine, such side effects are particularly concerning in patients with cardiac issues as these responses can exacerbate existing conditions.