The Journal of ExtraCorporeal Technology No 56-4 | Page 43

A . G . Beshish et al .: J Extra Corpor Technol 2024 , 56 , 174 – 184 181
Table 3 . Causes of comorbidity and death , and reintervention for patients requiring ECLS post-Norwood Operation .
Cause of death
Total number of deaths n = 38 (%)
Multi organ failure
12 ( 31.6 %)
Withdrawal of support / redirection of goals of care
10 ( 26.3 %)
Cardiac arrest after ECLS decannulation
6 ( 15.8 %)
Sepsis / septic shock
5 ( 13.2 %)
severe neurological injury
5 ( 13.2 %)
Reintervention
Total number reintervention n = 6 / 65 ( 9.2 %)
Revision of Aortic Arch / Revision of ( DKS ) Damus Kaye Stansel
5
Shunt revision
1
Table 4 . Functional Status Scale ( FSS ) for post-Norwood ECLS survivors on admission and discharge stratified by PaO 2 levels into hyperoxia group ( PaO 2 > 182 mmHg ) and non-hyperoxia group ( PaO 2 182 mmHg ).
ECLS group
FSS domain
Admission
Discharge
p-value
Mean
SD
Mean
SD
Non-Hyperoxia Group ( PaO 2 182 mmHg ) ( n = 19 )
Mental Status
1
0
1.1
0.5
0.331
Sensory Function
1
0
1
0
Communication
1
0
1.1
0.2
0.331
Motor Functioning
1
0
1.1
0.5
< 0.0001
Feeding
1
0
2.9
0.5
0.042
Respiratory Status
1
0
1.2
0.4
< 0.0001
Total Score
6
0
8.4
1.2
< 0.0001
Hyperoxia Group ( PaO 2 > 182 mmHg ) ( n = 8 )
Mental Status
1
0
1.1
0.4
0.351
Sensory Function
1
0
1.1
0.4
0.351
Communication
1
0
1.1
0.4
0.351
Motor Functioning
1
0
1
0
Feeding
1
0
3
0
Respiratory Status
1
0
1.4
0.7
0.197
Total Score
6
0
8.8
1.4
0.001
Results depicted as mean , and standard deviation ( SD ). Subscale scores range from 1 to 5 . Total scores are the sum of subscale scores ranging from 6 to 30 . p-value : paired t-tests
Table 5 . New morbidity and unfavorable functional outcome for overall survivors who required ECLS post-Norwood operation stratified by PaO 2 levels into hyperoxia and non-hyperoxia groups based on functional status scale change from admission to discharge .
ECLS group
New morbidity ( change in FSS score 3 points )
Unfavorable outcome ( change in FSS score 5 points )
Overall Cohort of Survivors ( n = 27 )
7 ( 26 %)
2 ( 7 %)
Non-Hyperoxia Group Survivors ( n = 19 ) ( PaO 2 182 mmHg )
4 ( 21 %)
1 ( 5 %)
Hyperoxia Group Survivors ( n = 8 ) ( PaO 2 > 182 mmHg )
3 ( 38 %)
1 ( 13 %)
FSS : Functional Status Scale ; ECLS : Extracorporeal Life Support .
Despite previous studies , there is no generally accepted definition of pathologic hyperoxia . Injurious hyperoxia may vary by patient population and clinical context [ 32 ]. As we know , the oxygen content of blood consists of bound oxygen to hemoglobin , and dissolved oxygen in the form of PaO 2 . Despite knowing that the bound oxygen by far is the main contributor for oxygen content in blood , the dissolved oxygen ( PaO 2 ) is what is important at the cellular level . Poor outcomes may occur when PaO 2 exceeds a certain threshold of antioxidation systems of the body . This is biologically plausible as endogenous antioxidants may prevent oxidative stress at lower PaO 2 . Whenhigh amounts of oxygen are introduced to previously ischemic tissues , this leads to the generation of reactive oxygen species ( ROS ) and activation of inflammatory pathways via cytokines and other immunological signaling pathways . The generation of oxygen free radicals causes damage to the cell membrane integrity due to lipid peroxidation and protein changes , ultimately resulting in premature cell death [ 36 ]. Production of ROS can result in the dysfunction of organ systems including the immune system . This dysregulation may result in multiorgan dysfunction in the form of renal failure , cardiac dysfunction , and respiratory failure . These may ultimately increase the overall