Which test should a nurse perform to evaluate a client's ability to safely ambulate when ataxia is present?

The correct choice is Romberg's test, which is specifically designed to assess balance and proprioception. When ataxia is present, it often indicates issues with coordination and balance due to neurological impairment. Romberg's test evaluates how well a person can maintain their balance when standing with their feet together, both with eyes open and closed. The test provides insight into the functioning of the vestibular and proprioceptive systems, which are crucial for safe ambulation.

In ataxic patients, the inability to maintain stability during this test can suggest significant deficits in their ability to ambulate safely, leading to a higher risk of falls. This direct assessment of balance helps the nurse determine the level of support and intervention needed to ensure the client's safety while walking.

Gait analysis, while useful, primarily focuses on the mechanics of walking rather than balance. The blood pressure standing test evaluates orthostatic hypotension and is not relevant to assessing balance. The balance beam test might measure balance, but it is less standardized than Romberg's test and could be less practical in immediate assessments of ataxia.