Portable suction machine should be part of crash cart trolley because emergencies can occur anywhere, your suction may need to travel with the patient and portable suction acts as a back-up when in-wall suction machine is not properly working during an emergency.
Source: Never Miss Carrying Potable Suction Machine in the Crash Cart Trolley – Here’s Why
Source: Never Miss Carrying Potable Suction Machine in the Crash Cart Trolley – Here’s Why