HIGH-VOLUME SUCTION APPARATUS
Section I. OPERATIONAL PROCEDURES
The high-volume, low-pressure suction apparatus is found in most hospital wards
and recovery and emergency rooms. Its most common use is in recovery. For
example, following chest surgery, a catheter is placed in the patient's pleural cavity.
The catheter is connected to a collection bottle and the suction source. The high-
volume suction pump supplies a vacuum of 0 to 60 centimeters of water (cmH2O) to
keep body fluids drained. The removal of fluids is vital as it aids in prevention of
infection and allows the wound to heal faster. The unit, once set, maintains a constant
Now that you know what the suction apparatus does, the lesson will discuss the
major components which make it function.
a. Vacuum Motor. The vacuum motor is identified as M1 in the schematic
wiring diagram shown in figure 1-1. It operates in the vane method, but in this case, the
vanes are fixed (non-movable). The vanes extend from the motor to the housing. As
the motor spins, the vanes pull a vacuum at one or more openings and push the air out
of another opening. This creates suction to the collection bottle. The motor is replaced
as a unit.
b. Off/On Switch. The off/on switch is identified as S1 in the schematic (figure
c. Convenience Outlet. The convenience outlet is shown in the schematic. It
is neither a load device nor is it controlled by the off/on switch.
d. Pilot Light. The pilot light is lit when the switch (S1 in the schematic) is
e. Variac Switch. Labeled A1 in the schematic (figure 1-1), the Variac is a
speed control. The winding between A1-2 and A1-3 is the power source for the M1