Final answer:
The nurse should monitor the client with hypomagnesemia for muscle weakness and disorientation, as these symptoms directly relate to magnesium's role in neuromuscular and neurological functions.
Step-by-step explanation:
The student is inquiring about the clinical manifestations to monitor in a client with hypomagnesemia induced by prolonged lansoprazole therapy. Magnesium plays an important role in various bodily functions, including muscle contraction, nerve function, and the maintenance of heart rhythm. Hypomagnesemia can lead to various complications, and the nurse should monitor for signs that reflect these systemic effects.
Hypomagnesemia can cause muscle weakness, hypotension, arrhythmias, and disorientation due to its role in neuromuscular and cardiovascular function. Therefore, of the options listed, muscle weakness and disorientation are most directly related to hypomagnesemia. Muscle weakness occurs due to the role of magnesium in neuromuscular transmission and muscle contraction, while disorientation can result from the effects of magnesium on neurological function.