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Implanted date: device was not implanted.
Explanted date: device was not explanted.
Pma/510(k)- k130280.
The actual sample was received for evaluation.
Visual inspection did not reveal breakage or any other anomaly that could result in the decrease in the gas transfer performance in the appearance.
Air was blown into the gas channel of the actual sample.
As a result, liquid was found flowing out from the gas out port.
The liquid was subjected to protein test paper (uriace from terumo) and presence of protein in the liquid was confirmed.
Physiological saline solution was flown into the actual sample by gravity and the oxygenation module was inspected visually.
No formation of blood clot was observed.
The inside of the oxygenation module was fixed by being filled with glutaraldehyde-containing saline solution.
Then, the housing and the filter were removed and both surfaces of the filter were subjected to visual inspection.
Formation of minute blood clots was found visibly on the outer surface of the filter.
The oxygenation module was visually inspected.
No visible formation of blood clots was confirmed.
The fiber layer was removed gradually by 2mm in thickness and the surface of each layer was subjected to visual inspection.
No visible formation of blood clots was confirmed.
The heat exchanger was removed from the outer cylinder and subjected to visual and magnifying inspections.
Red clots and white clots were found to have formed on each side.
Both sides of the filter that had been removed were inspected under magnification.
Red clots and white clots were found to have formed on both sides.
No anomaly was observed in the diameter of the filter mesh.
The fiber layers that were removed were inspected under magnification.
On those in the inner layers, there were some point where hydrophilization of fiber seemed to have occurred.
No formation of blood clots was observed on the surface.
Electron microscopic inspection of the filter found adhesion of blood cell components such as platelet, rbc, deformed rbc (echinocyte) on both the outer and the inner surfaces of the filter.
Electron microscopic inspection of the fiber layers found adhesion of blood cell components such as platelets, rbc, and echinocytes on all layer.
No aggregation of blood components that could lead to the formation of blood clots was observed.
Electron microscopic inspection of the blood clots found adhesion of blood components such as platelets, rbc, and echinocyte, and formation of fibrin nets.
The cross-section of the fiber (since the cross-section of the fiber may be crushed when cut with a blade, the fiber was frozen with liquid nitrogen and then fractured for this inspection) was examined with sem for the possible hydrophilized points.
As a result, trace of plasma leak was observed.
The thickness and the state of micropores of the cross section in which no hydrophilization seemed to have occurred was evaluated and confirmed to be in the same condition as those of a current product sample.
A review of the device history record and product release decision control sheet of the involved product code/lot# combination was conducted with no findings.
Review of the pump record revealed: at 13:58, cpb on.
At 19:23, exchange of oxygenator was done.
The pressure drop changed in accordance with the change of flow rate.
No increasing tendency was observed.
Based on this, it is likely that no obstruction occurred during the actual use due to some factors such as formation of blood clots.
At 15:34, rewarming started.
From then until 18:30 when the rectal temperature became stable around 36, svo2 decreased in accordance with the increasing rectal temperature.
Po2 was kept around 200mmhg by increasing fio2.
From 18:30 when the rectal temperature became stable until the exchange of oxygenator, po2 decreased in spite of fio2 having been kept 100%.
Ifu states: upon patient rewarming, adjust o2 concentration, gas flow rate and blood flow rate by increasing them as needed based on an increase in patient's metabolism.
Failure to adjust the gas supply and the blood flow rate appropriately may cause insufficient o2 supply needed or the amount of the patient's gaseous metabolism.
Measure blood gases and make necessary adjustments as follows.
Control pao2 by changing concentration of oxygen in ventilating gas using gas blender.
To decrease pao2, decrease fio2.
To increase pao2, increase fio2.
A phenomenon called wet lung may occur when water condensation occurs inside fibers of microporous membrane oxygenators with blood flowing exterior to the fibers.
This may occur when oxygenators are used for a longer period of time.
If water condensation and/or a decrease in pao2 and/or an increase in paco2 is noted during extended oxygenator use, briefly increasing the gas flow rate may improve the performance.
Increase gas flow rate, to 20 l/min for 10 seconds.
Do not repeat this flushing technique, even if oxygenator performance is not improved.
Based on the provided information and investigation results, there is no definitive evidence that this event was related to a device defect or malfunction.
It is likely that the poor gas transfer performance during the event might have been caused due to the combination of the volume of supplied o2 became insufficient for the o2 consumption volume that increased due to the patient's metabolism activated by the rewarming, which resulted in the decrease in svo2 and the decrease in pao2 accordingly; some parts of the fibers had become hydrophilic (plasma leak).
Due to this, the contact between blood and o2 gas was obstructed, resulting in the decrease in oxygenation performance.
As a cause of the plasma leak, it is likely that a change in the blood properties may have occurred and produced a substance with a surface-active effect.
This reduced the surface tension of blood on the surface of the micropores of the fiber, causing a condition where plasma leak tended to occur.
However, the exact cause of the reported event cannot be definitively determined based on the available information.
(b)(4).
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The user facility that the involved capiox device was used during the procedure.
An ecc was performed in tar+cabg case.
When the pump was on, pao2 decreased gradually.
In 300 min from when the pump was on, pao2 decreased to 80 level while blood flow rate
=
4.
6l/m, gas flow rate
=
5l/m, fio2
=
100%, and svo2
=
70%.
Ventilation support by anesthesiologist improve pao2 temporarily, however, decreasing blood flow or increasing gas flow did not work.
The actual sample was changed out.
The estimated blood loss was 260ml.
The patient was not harmed.
The procedure outcome was not reported.
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