When testing a mechanical suctioning unit, you should turn on the device, clamp the tubing, and ensure that it generates a vacuum pressure of more than:

• A. 100 mm Hg
• B. 200 mm Hg
• C. 400 mm Hg
• D. 300 mm Hg

Answer: (D)

The essential idea is that a suction device must produce enough negative pressure to be clinically effective without harming tissue. For adult airway suctioning, a target around 300 mm Hg of vacuum is the standard reference. When you test the unit, you turn it on and clamp the tubing to read the vacuum; you’re checking that the device can generate a pressure exceeding or at least reaching 300 mm Hg. Readings well below that (like 100 or 200) wouldn’t be sufficient to remove secretions reliably, while a higher reading (such as 400) would still meet the requirement, but the test is assessing whether it meets the minimum threshold. Therefore, 300 mm Hg is the appropriate value to verify as the minimum acceptable suction pressure.