A client with psoriasis returns to the clinic reporting the persistence of several silvery, scaly areas on the elbows and palms that frequently burn and sometimes bleed.
Which prescription should the nurse teach the client to use for the skin condition?

Measuring oxygen saturation is not directly relevant to the administration of vancomycin or the monitoring of its potential side effects. While oxygen saturation is important to assess in patients with respiratory concerns, it does not provide information about kidney function, which is essential for safe vancomycin use.

Choice B rationale:

Auscultating bowel sounds, while a part of general abdominal assessment, is not the most crucial action before administering vancomycin. Vancomycin is not known to have significant effects on bowel motility, and its primary concern is nephrotoxicity.

Choice C rationale:

Assessing body temperature can be helpful in evaluating for infection, but it is not the most specific or sensitive indicator of vancomycin-related adverse effects. Fever can be a sign of various conditions, and it does not directly assess kidney function.

Choice D rationale:

Checking serum creatinine is the most essential action before administering vancomycin because it allows for assessment of kidney function. Vancomycin is primarily excreted by the kidneys, and impaired renal function can lead to elevated drug levels and increased risk of nephrotoxicity. By checking serum creatinine, the nurse can ensure that the patient's kidney function is adequate to safely excrete vancomycin and can adjust the dosage or frequency of administration if necessary.

Choice A rationale:

Lactulose is a non-absorbable disaccharide that is metabolized by bacteria in the colon to produce lactic acid and acetic acid. These acids acidify the colon, which traps ammonia (NH3) in the colon and converts it to ammonium (NH4+). Ammonium is not absorbed by the colon and is excreted in the stool. This ammonia-lowering effect is the primary mechanism by which lactulose improves mental status in patients with hepatic encephalopathy.

Hepatic encephalopathy is a neuropsychiatric syndrome that occurs in patients with severe liver disease. It is caused by the buildup of ammonia in the blood, which can cross the blood-brain barrier and cause cerebral edema and impaired brain function.

The clinical manifestations of hepatic encephalopathy range from mild confusion and personality changes to coma. Improved mental status is a key therapeutic goal in the treatment of hepatic encephalopathy.

Studies have shown that lactulose can improve mental status in patients with hepatic encephalopathy. A meta-analysis of 11 randomized controlled trials found that lactulose was associated with a significant improvement in mental status compared to placebo.

The improvement in mental status is typically seen within 24 to 48 hours of starting lactulose therapy.

Choice B rationale:

Increased urine output is not a direct therapeutic effect of lactulose. Lactulose can cause diarrhea, which can lead to increased urine output due to fluid loss. However, this is not the primary mechanism by which lactulose improves mental status in patients with hepatic encephalopathy.

Choice C rationale:

Reduction in the number of liquid stools is a common side effect of lactulose. However, it is not a therapeutic goal in the treatment of hepatic encephalopathy. The goal of lactulose therapy is to improve mental status by lowering ammonia levels in the blood.

Choice D rationale:

Ability to ambulate independently is not a direct therapeutic effect of lactulose. Lactulose can improve mental status, which may indirectly lead to improved ambulation in some patients. However, this is not the primary mechanism by which lactulose works.