J Extra Corpor Technol 2024 , 56 , 203 – 206 Ó The Author ( s ), published by EDP Sciences , 2024 https :// doi . org / 10.1051 / ject / 2024019
Available online at : ject . edpsciences . org
CASE REPORT
High pressure excursion in a radial design oxygenator
Ashley Svec ( BS ), Tyler Eadie ( MS , CCP ), Brandon D ’ Aloiso ( MS , CCP ) * , and Peter Arlia ( CCP , MBA )
UPMC Presbyterian Perfusion , 200 Lothrop Street , Pittsburgh , PA 15213 , USA Received 2 April 2024 , Accepted 21 July 2024
Abstract – Oxygenator high-pressure ( HPE ) is a phenomenon that can occur during cardiopulmonary bypass ( CPB ) in which the oxygenator inlet pressure increases rapidly , thereby limiting flow . Most perfusionists globally do not use inlet oxygenator pressure monitoring and therefore HPE is not often recognized . HPE may occur for various reasons , and it is not fully understood . Patient factors that put a patient at a higher risk of HPE are increased body surface area , blood type , and hematocrit count . Patient size , blood flow , and pressure drops of the oxygenator incorporated into the circuit can also increase the probability of an HPE occurring . This case study overviews our experience when dealing with an interesting case of HPE and the most up-to-date knowledge on appropriate steps to mitigate the effects on the patient .
Key words : Cardiopulmonary bypass , High pressure excursion , Case report .
Overview
Oxygenator high-pressure excursion ( HPE ) is a phenomenon that can occur during cardiopulmonary bypass ( CPB ) in which the oxygenator inlet pressure increases rapidly , thereby limiting flow . The mechanism of HPE is not fully understood , but the literature describes aggregation of platelets and swelling of oxygenator fibers to be possible causes [ 1 ]. HPE can lead to the necessity of an oxygenator changeout while on CPB due to this limited flow . This limited flow may go unnoticed if there is no oxygenator inlet pressure monitoring ; however , less than 10 % of perfusionists have inlet pressure monitoring incorporated into their circuit [ 2 ]. Patients with a large body surface area ( BSA ), high hematocrit , acute or emergent surgery , and a history of stroke are known to be at a higher risk for HPE during CPB [ 3 ]. Blood types have also been seen to affect the possibility of an HPE . A study conducted by Myers et al . [ 4 ], tested the blood of 31 patients who had an HPE occurring on CPB ; it was concluded that 51.6 % of patients with O-positive blood had experienced HPE . In cases where HPE occurs , many temporizing measures can be taken such as additional anticoagulation , hemodilution , Epoprostenol administration and , in unresolving cases , oxygenator changeout [ 3 ]. The Medtronic Affinity Fusion Oxygenator used features a Balance TM * Biosurface coating that is a hydrophilic polymer coating without heparin for cardiopulmonary bypass circuit devices that reduces platelet adhesion and activation and preserves platelet function . The Terumo FX25 features the Terumo
* Corresponding author : daloisobd @ upmc . edu
X-Coating which is an albumin-based coating . Currently , no albumin is added to the prime at our center . Much of the literature surrounding HPE discusses cases in which roller pumps were used and therefore describe pressure measurements 500 mmHg . Contemporary centrifugal-based CPB systems do not generate pressures this high during normal operating conditions and therefore have a different set of considerations when diagnosing and treating HPE but lessons from roller pumps are nonetheless important to understanding this phenomenon . In addition , there is literature surrounding HPE with trans-oxygenator pressures such as the study conducted by Fisher et al . [ 5 ]. The HPE in this incidence is unique due to the use of the centrifugal CPB system and radial-designed oxygenator .
Description
A 46-year-old male presented to the operating room at UPMC Presbyterian on October 30 , 2023 , with an ascending aortic aneurysm . The patient was found to have a calcified bicuspid aortic valve , aortic regurgitation , and hypertension . An aortic valve replacement , hemiarch replacement , and aortic root replacement with deep hypothermic cardiac arrest ( DHCA ) and retrograde cerebral perfusion were planned . The patient ’ s blood type was O-positive . Pre-operative laboratory tests were within normal limits : hematocrit 41.5 %, prothrombin time ( PT ) 14 s , APTT 32 s , platelets 246,000 / mL , BUN 17 / dL , and creatinine 0.8 / dL . The patient ’ s body surface area was 3.1 m 2 , and the calculated minimal flow to provide adequate
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( https :// creativecommons . org / licenses / by / 4.0 ), which permits unrestricted use , distribution , and reproduction in any medium , provided the original work is properly cited .