CFL-M Inca
Protocol Inca measurement
Author : Dinant Goorhorst, May 2014
Introduction
This info sheet gives a brief description of a stepwise
protocol of starting a Pressure Volume Measurement.
Read also: ‘Quick start: How to perform a PV-study’ in
the Inca user manual.
Choice of Catheter
Optimal pressure-volume recordings require that you
use the right catheter. Read info sheet ‘Select the best
catheter’ to read information on which catheter to use
for different ventricular sizes and how to optimize
catheter settings
CD Leycom offers catheters with electrode spacings 6,
8, 10 or 12 mm.
Study preparation
Enter study settings
During preparation of the patient, enter the study
settings. Start with creating a new study. You must fill
in a study name and an ID number.
Protocol Inca – Monitoring
Check the software settings
1. Choice of catheter
Based on fluoroscopy or Echo/MRI values of
EDV/ESV – EF
Longaxis (mm) -> catheter type
<
<
<
>
55mm
70mm
90mm
90mm
-
6 mm electrode spacing
8 mm electrode spacing
10 mm electrode spacing
12 mm electrode spacing
Select “Scaling” and check the scaling values. Normally
during start-up all channels are set to ‘Auto-scale’.
Select “Catheter” in the settings menu. Enter the
current catheter that will be used.
Select “Channels” in the settings menu. Check and
update the channel names and units for the external
signals. Check also the channel-view assignment. The
pressure will be used in the PV-loop and the ECG will
be used to find the markers.
2. Study preparation
a. Enter study settings
b. Check software settings
3. Catheter placing
a. Connect catheter to Pressure Module
b. Optimal positioning -> pigtail in apex,
Segment 7 around aortic valve (less than 1 cm
under valves)
c. Fixation catheter when optimal position
reached.
4. Volume calibration
a. SV calibration by Thermodilution – preferably 3
to 5 shots
b. Alternated by EFcal
10ml of 6% saline when CO < 8L
10ml of 10% saline when CO> 8L
-> to data 1… files + manual input SVcal or from
SVcal files
-> real-time absolute values
The calibration of the conductance catheter is done
automatically, however the user-supplied signals
connected to the external inputs require initial
calibration to enable the software to convert input
signal voltages to user units.
þ Note
Select ‘Create new study’ during start-up, you
will guide through these steps automatically.
CD Leycom info 1423
CFL-M Inca
Protocol Inca measurement
Author : Dinant Goorhorst, May 2014
Catheter placing
Measurement
Prepare catheter
Start your measurement always with a baseline.
It is recommended to repeat a baseline (during and)
after a measurement to verify if the situation is still the
same (for instance: all the segments are still in the
ventricle.)
Flush the catheter first with a sterile saline solution.
Then wet the sensor by immersing the distal portion of
the catheter for approximately 10 seconds in a saline
solution. Remove the catheter from saline, lay catheter
on sterile table and cover sensor with sterile by saline
wetted gauze.
Connect catheter’s pressure arm
Connect the catheter’s pressure arm to the pressure
module of the Inca. On the screen you have to confirm
that pressure calibration can be started.
þ Important
The catheter should not be moved or touched
until the pressure calibration is ready (after
approximately 15 seconds).
Optimal positioning
þ Optional
During the insertion of the catheter, you may
record the aorta pressure.
During insertion of the catheter check the pressure
curve to see if the pressure curve is changing from
aorta pressure to left ventricular pressure.
Connect the catheter’s volume arm to the volume
module of the Inca.
Select the screen with the segmental volumes. Check
the segments who are moving simultaneously.
þ Optional
If 5 or less segments are in the ventricle,
decrease the electric field by changing the
current electrodes.
Determination of slope factor SVcal
Determine CO by a reference method following
standard procedure. This could be performed by
thermodilution to achieve a reliable average 5
measurements will be optimal. Each time that Cardiac
Output is measured, using a reference method, data is
acquired simultaneously with Conduct NT.
Enter the value of the reference method in your
comment and select the type ‘SVcal’. Now you can also
enter the CO in the column ‘COref’.
Determination of EFcal by measuring parallel
conductance
Acquire the EFcal-files during a saline injection. Use 10
ml of 6% with a CO less than 8L and use 10 ml of 10%
with a CO above 8L.
Wait for a steady state (2 – 3 seconds) as judges by
the stability of the PV-loops. Start data-acquisition and
inject the hypertonic saline through the distal port of
the thermodilution catheter. The PV-loops move to the
right because the volume is increasing slightly. Wait for
the wash-out of the saline and PV loops starting to
return to normal then stop acquisition. Fill in a
comment and select the type ‘EFcal’.
You can read the result of the saline injection directly
in the displayed table. If you have three results close
to each other, you know that you do not have to
repeat the saline injection.
If there is still some doubts regarding the results, you
can repeat the saline once again.
þ Note
It is recommended to wait a while before you
repeat a saline injection. In the mean time you
can acquire an SVcal file after each EFcal-file or
do a visual check on the acquired EFcal-files.
Use 11 electrodes with 5 segments.
Use 10 electrodes with 3 or 4 segments.
þ Note
It is recommended to display at least 1 segment
that is outside the ventricle.
þ Optional
If MRI or Echo values available for EDV and
ESV, you may prefer to use these values to
calibrate volume.
CD Leycom info 1423