B30 Patient Monitor
8-30
Document no. 2044677-001
7.2.1 CO
2
measurement
‘REPLACE D-FEND’ message Amb – Work pressure difference too big.
Indicates residue build-up on the water trap membrane. This decreases
air flow. Replace the D-fend.
‘SAMPLE LINE BLOCKED’ message Amb – Work pressure difference too big.
Sampling line or water trap is occluded. Water trap container is full. If
occlusion persists, check internal tubing for blockages.
No response to any gas Check Sample Gas Out.
Amb - Work pressure low, flow too small and pump voltage too high.
Sampling line, water trap, or internal tubing is blocked or loose, or
improperly attached. Gas out connector or tubing is blocked.
Zero valve malfunction. Pump failure or pump is worn. Supply voltage
missing. Serial communication error.
Sudden increase in gas display Water trap malfunction. Check all internal tubing and the interior of the
water trap for occlusions or leaks. Replace water trap. Check flow rates.
Abnormally high (or abnormally
low response to CO
2
or sudden occlusion warning
Pressure transducer failure. Check the Ambient and Amb – Work
pressures in Ga s e s service menu.
Strong drift in all gases Leak in sampling line or internal tubing (especially in conjunction with too
low readings).
Problem Cause What to do
Action
too low ETCO
2
value
• sudden decrease in circulation
• pulmonary embolism
• hyperventilation
• very large dead-space
• large shunting
• leak in sampling system
• calibration error
• high by-pass flow from ventilator
• check all connections
• check calibration
too high ETCO
2 • hypoventilation
• increased metabolism
• D-fend contaminated
• calibration error
• change D-fend
• check calibration
waveform clipped
• incorrect scaling • change scale
Problem Cause/What to do