A nurse is caring for a client who has a new prescription for an ipratropium inhaler to control COPD bronchospasm.
For which of the following adverse effects should the nurse monitor?

Choice A rationale

A urine output of 240 mL in a 12-hour period translates to 20 mL/hr, which is significantly below the normal physiological range of 30 mL/hr or greater. While low urine output can indicate dehydration, severe oliguria often points to acute kidney injury or severe hypovolemia, not solely dehydration. Normal urine output is generally considered to be 0.5-1 mL/kg/hr.

Choice B rationale

A BUN of 18 mg/dL falls within the normal range of 10 to 20 mg/dL. In dehydration, the kidneys reabsorb more water, leading to a disproportionate increase in BUN relative to creatinine due to increased urea concentration in the tubules, reflecting hypovolemia. A normal BUN value does not indicate dehydration.

Choice C rationale

A weight loss of 0.61 Kg (1.34 lb) in 24 hours is a significant and rapid reduction in body mass. This acute fluid deficit directly reflects a negative fluid balance, indicating a loss of body water. Each kilogram of weight loss approximates 1 liter of fluid loss, making this a clear indicator of dehydration due to fluid volume deficit.

Choice D rationale

A blood pressure of 100/70 mm Hg is within the normal range for many individuals, although it is on the lower side of normotension. While hypotension can be a late sign of severe dehydration, especially orthostatic hypotension, a reading of 100/70 mm Hg alone does not definitively confirm dehydration as the primary cause.

Choice A rationale

Ipratropium is an anticholinergic bronchodilator that blocks muscarinic receptors in the bronchial smooth muscle, leading to bronchodilation. A common adverse effect of anticholinergic medications is reduced salivary gland secretion, resulting in xerostomia, or dry mouth, due to inhibition of parasympathetic stimulation.

Choice B rationale

Periorbital edema is not a typical adverse effect of ipratropium. This medication primarily targets muscarinic receptors in the respiratory tract. Edema, particularly around the eyes, is more commonly associated with allergic reactions or fluid retention from other medications.

Choice C rationale

Ipratropium, being an anticholinergic, primarily acts on M3 receptors in the lungs and has minimal systemic absorption, thus rarely causing bradycardia. In fact, anticholinergics can sometimes cause a mild increase in heart rate due to blockade of M2 receptors in the heart, but clinically significant changes are uncommon.

Choice D rationale

While xerostomia can contribute to dental issues over time due to reduced saliva's protective effects, dental caries is not a direct, acute adverse effect of ipratropium itself. It is a potential long-term complication of prolonged dry mouth, rather than a direct drug-induced effect to monitor immediately.