User's Manual

SvO

20-11

Correcting Out-of-Range Light Intensity

Each time you perform a light intensity calibration, the oximetry module stores the

intensity value and signals an alarm or error message if the current light level

differs significantly from the stored level. Light intensity error messages serve as a

reference to determine if the light at the catheter tip is adequate for accurate

monitoring. Do not ignore these messages.

The module alerts you to this condition when:

• an INTENSITY ALERT or SVO2 DATA OUT OF RANGE message is

displayed; or

• a second level alarm begins.

When the monitor displays the SVO2 DATA OUT OF RANGE or INTENSITY

ALERT message, select the intensity display feature to view a history of light

intensity values. Refer to Figure 20-4 to identify the type of abnormal intensity.

Refer to the following list of possible causes and solutions.

• High — check the position of the catheter as the tip may lie against the vessel

wall. Reposition the catheter according to your hospital protocol.

• Low, dampened, or erratic — check the blood flow past the catheter as a clot

may have formed over the catheter tip.

Figure 20-4: Abnormal intensities

Take the following actions:

• If a Spacelabs Medical invasive pressure module is being used, examine the

pulmonary artery (PA) pressure waveform for spontaneous wedge indicating

the catheter tip may lie against the vessel wall. If this occurs, reposition the

catheter.

• If a Spacelabs Medical invasive pressure module is being used for pulmonary

artery pressure monitoring, examine the pressure waveform for dampening,

indicating clotting over the tip of the catheter. If this occurs, follow hospital

procedure to flush the distal lumen. Reposition the catheter if necessary.

• Abnormal resistance when you push the catheter through the distal lumen

indicates damage to catheter fiber optics. Reposition the catheter and replace

if necessary.

• If connections between the catheter optical connector and the optical module

appear loose, tighten the connections.

• If the catheter contains obvious kinks, the optical fibers may be damaged.

Replace the catheter.