- The "GAS ESCAPE" system is designed to avoid any possible risk of
blocking the gas outlet; such blockage could cause the immediate
passage of air to the blood compartment.
- SORIN GROUP ITALIA recommends the use of a bubble trap or filter
on the arterial line to reduce the risk of emboli transmission to the
patient.
10) VAPOROUS ANAESTHESTICS
The oxygenator is suitable for use with volatile anaesthetic isoflurane and
sevoflurane, by mean of a suitable narcosis gas evaporator.
If these vaporous anaesthetics are used, some method of scavenging the gas
from the oxygenator should be considered.
The protocol, the concentration and the monitoring of the anaesthetic gases
administrated to the patient, is under the sole responsibility of the physician in
charge of the treatment.
The only volatile anaesthetics suitable for this use are isofluorane and
sevolfuorane
methods adopted for vaporous anaesthetic gas scavenging should not
increase or reduce in any way the pressure level at the oxygenator
fibres.
F. PRIMING AND RECIRCULATION PROCEDURE
Do not use alcoholic priming solutions: such solutions could compromise the
proper function of the oxygenating module.
1) KEEP THE GAS FLOW OFF
2) KEEP THE OXYGENATOR PURGING/RECIRCULATION
LINE CLOSED
Check that the purging-recirculation stopcock is closed.
3) CLOSE VENOUS AND ARTERIAL LINES
Clamp the venous line. Clamp the arterial line some centimetres away from
arterial outlet connector of the oxygenator.
4) CHECK THE HEAT EXCHANGER
Verify again the integrity of the heat exchanger, paying particular attention to
possible water leaks.
5) VENOUS RESERVOIR PRIMING
Secure with ties all aspiration lines connected to the Cardiotomy Reservoir. Fill
the Cardiotomy Reservoir through the "Quick Priming Port" (fig.2, Ref. 16) with
sufficient liquid to ensure the intended haematocrit is obtained, taking into
account:
-
the static priming volume of the oxygenator is 160 ml;
-
the 3/8" tube capacity is 72 ml/m;
-
the 1/2" tube capacity is 127 ml/m.
Clamp the Venous Reservoir outlet.
In order to fill the Venous Reservoir or if the Cardiotomy Reservoir capacity
(1200 mls) is not enough, open the connection to the Venous Reservoir by
raising the connection key (fig.2, ref.3) on the top of the Cardiotomy Reservoir.
6) CIRCUIT PRIMING
- The pressure level inside the blood compartment of the oxygenating
module shall not exceed 100 KPa (1 bar / 14 psi).
Clamp the venous reservoir outlet and remove the pump segment from the
arterial pump head. Fill the pump segment by keeping it at the same height as
the Venous Reservoir and slowly opening the clamp occluding it. By slowly
bending downward the tube segment to be filled, the air in the tube will be
routed to the oxygenator. The complete priming of the oxygenating module is
completed by gravity. Once the D 905 EOS is filled, place the pump segment
in the arterial pump.
7) OPEN VENOUS AND ARTERIAL LINES
Remove the clamp from the venous and arterial lines and increase flow up to
2000 ml/min.
8) OPEN THE PURGING/RECIRCULATION LINE
Once the steps up to and including point 7 have been carried out, increase the
arterial pump speed until the flow reaches the maximum value of 5l/min. Open
the purging/recirculation stopcock for some seconds in order to prime the
oxygenator purging/recirculation line.
9) PURGE THE AIR CONTAINED IN THE CIRCUIT
During this phase it is necessary to tap the entire circuit in order to facilitate
the removal of microbubbles from the tube walls. After some minutes in which
the flow is maintained at a high rate, all air will be evacuated.
10) CLOSE THE PURGING/RECIRCULATION LINE
After 3-5 minutes in which the flow is maintained at a high rate, all air will be
evacuated and it is possible to close the purging/recirculation line from the
dedicated stopcock.
11) CLOSE THE VENOUS AND ARTERIAL LINES
- Do not use pulsatile flow during priming.
- Check the correct dosage of anticoagulant in the system before
starting the bypass.
- SORIN GROUP ITALIA recommends the use of the pump speed
control to reduce or stop the arterial flow slowly.
- Do not use the pump on/off switch until the pump speed is zero.
- If the reduction connector (D523C) and a circuit have been connected
to the coronary outlet port, check the priming of the connected line.
- Clamp the line some centimetres away from the outlet.
- Do not create a negative pressure at the coronary outlet. Negative
pressure in the blood compartment could cause microbubble
formation.
G. INITIATING BYPASS
1) OPEN THE ARTERIAL AND VENOUS LINES
Remove first the clamp from the arterial line, then remove the clamp on the
venous line. Start bypass with a blood flow appropriate to patient size. Check
constantly the blood level in the Venous Reservoir.
2) CHECK THE CORRECT OPERATION OF THE HEAT
EXCHANGER
Check the temperature of the venous and arterial blood.
3) SELECTION OF THE APPROPRIATE GAS FLOW
The suggested gas/blood flow ratio in normothermia is 1:1 with a Fi0
80:100%.
- Always open the gas flow after the blood flow. The gas/blood flow
ratio must never exceed 2:1.
- The pressure in the blood compartment must always exceed that of
the gas compartment. This is to prevent gas emboli appearing in the
blood compartment.
4) BLOOD GAS MONITORING
After a few minutes of bypass operation, measure the gas content of the
blood. Depending on the values found, adjust the relevant parameters as
follows:
High pO
2
Low pO
2
High pCO
2
Low pCO
2
H. DURING BYPASS
1) CHECK THE VENOUS RETURN
If a higher venous return flow is necessary lower both the oxygenator and the
venous reservoir with respect to the patient position.
- The ACT (Activated Coagulation Time) must always be longer than or
equal to 480 seconds in order to ensure adequate anticoagulation of
extracorporeal circuit.
2) LOW FLOW RECIRCULATION
(Hypothermia associated with circulatory arrest).
a) Reduce the gas flow to less than 500 ml/min.
b) Open the purging/recirculation line and clamp the Venous Reservoir inlet
line (fig.2, ref.13).
c)
Reduce the flow from the arterial pump to 2000 ml/min.
d) Clamp the oxygenator arterial line (fig.2, ref.5).
e) Recirculate at a maximum flow of 2000 ml/min. throughout the patient's
circulatory arrest.
f)
To restart bypass after circulatory arrest, open the venous and arterial
lines and slowly increase the blood flow.
g) Close the purging/recirculation line (lever in "CLOSE" position).
h) Adjust gas flow.
3) VENOUS/CARDIOTOMY RESERVOIR MANAGEMENT
GB - ENGLISH
Decrease FiO
2
Increase FiO
2
Increase gas flow
Decrease gas flow
of
2
5