Philips MP40/50 Manuale Utente

Performing In-Vivo Calibration

Perform an in-vivo calibration:

• if you place the catheter in a patient without performing a pre-insertion calibration.

• if the catheter was disconnected from the optical module.

• when the catheter has been in the patient for 24 hours.

• if any significant change in light intensity occurs that the monitor cannot correct automatically.

Check for:

• proper positioning of the catheter in the patient.

• relatively stable oxygen saturation in patient.

• that the SvO

2

 light intensity indicator covers at least two divisions above the midpoint.

Be prepared to draw a blood sample from the patient.

In the 

 menu, select

.

To clear the distal lumen, draw off and discard at least 2 ml of blood before taking the sample.

Draw a blood sample from the distal port of the catheter and flush the line according to standard 
hospital practice.

Obtain laboratory analysis of the sample using direct measurements.

Compare the results with the stored calibration value displayed in the 

 menu. If the 

difference is less, or equal, to 4%, you can skip the next step.

If there is a difference of more than 4% between the stored value and the laboratory value, select 

 to adjust the stored value. Selecting 

 

recalls the 

previously stored calibration value.

Complete the calibration by selecting 

 (even if you did not adjust the 

calibration value). This updates the data stored in the optical module.

Oxygen extraction is the difference between the measured SpO

2

 and SvO

2

 values. If you are 

monitoring SpO

2

 and SvO

2

, the monitor can calculate this value and display it as a numeric. 

♦

To switch oxygen extraction calculation on or off, in the 

 menu, select 

 

and toggle between 

 and 

. 

♦

If more than one SpO

2

 value is available, you must choose which value is used in the calculation. 

In the 

 menu, select 

and select the required source.

If one of the calculation sources becomes unavailable, the monitor displays the INOP 

 for one minute. After this time, the calculation automatically switches off. 

If the missing source becomes available again, the calculation automatically switches on again.