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Observational Study
. 2022 Feb 1;23(2):e111-e119.
doi: 10.1097/PCC.0000000000002814.

Association Between Hyperoxemia and Increased Cell-Free Plasma Hemoglobin During Cardiopulmonary Bypass in Infants and Children

Catherine Gretchen  1   2 , Hϋlya Bayir  1   3   4   5 , Patrick M Kochanek  1   3   5 , Kristine Ruppert  6 , Melita Viegas  5   7 , David Palmer  5 , Nahmah Kim-Campbell  1   3
Affiliations
Observational Study

Association Between Hyperoxemia and Increased Cell-Free Plasma Hemoglobin During Cardiopulmonary Bypass in Infants and Children

Catherine Gretchen et al. Pediatr Crit Care Med. .

Abstract

Objectives: To determine potential risk factors for severe hemolysis during pediatric cardiopulmonary bypass and examine whether supraphysiologic levels of oxygen and cardiopulmonary bypass duration are associated with hemolysis.

Design: Prospective observational study.

Setting: Cardiac ICU in a university-affiliated children's hospital.

Patients: Greater than 1 month to less than 18 years old patients undergoing cardiopulmonary bypass for cardiac surgery.

Interventions: None.

Measurements and main results: Plasma samples from 100 patients to assess cell-free plasma hemoglobin levels were obtained at start cardiopulmonary bypass, at the end of cardiopulmonary bypass, and 2 and 24 hours after reperfusion. Arterial blood gas samples were obtained before and every 30 minutes during cardiopulmonary bypass. Patient demographics and laboratory data were collected from the electronic medical record. Plasma hemoglobin levels peaked at the end of cardiopulmonary bypass and haptoglobin levels continued to fall throughout all time points. There were 44 patients with severe hemolysis (change in cell-free plasma hemoglobin > 50 mg/dL). Younger age (odds ratio/sd 0.45 [95% CI, 0.25-0.81]) and higher mean Pao2 × cardiopulmonary bypass duration (31.11 [1.46-664.64]) were identified as risk factors for severe hemolysis in multivariable analysis. Severe hemolysis was associated with longer hospital and ICU lengths of stay as well as acute kidney injury.

Conclusions: We observed younger age and the exposure to both oxygen and duration of cardiopulmonary bypass as risk factors for hemolysis. Oxygen delivery through the cardiopulmonary bypass circuit is an easily modifiable risk factor. Its role in the production of reactive oxygen species that could alter the erythrocyte membrane deserves further examination in larger prospective studies.

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Conflict of interest statement

Dr. Bayir received funding from Nestle; she was supported by the University of Pittsburgh Medical Center Scientific Program. Drs. Bayir and Kim-Campell received support for article research from the National Institutes of Health (NIH). Dr. Kochanek received funding from Society of Critical Care Medicine and World Federation of Pediatric Intensive & Critical Care Societies for serving as the Editor-in-Chief of Pediatric Critical Care Medicine. Dr. Kim-Campbell was supported by the Ann E. Thompson Fellow Scholarship Award; she received funding from University of Pittsburgh Clinical and Translational Science Institute (UL1 TR000005), the Vascular Medicine Institute, the Hemophilia Center of Western Pennsylvania, the Institute for Transfusion Medicine, and the NIH (T32HD040686, K12HL109068, K23HD100553). The remaining authors have disclosed that they do not have any potential conflicts of interest.

Figures

Figure 1.
Figure 1.
(A) Cell-free plasma hemoglobin levels increased from Start CPB during and in the 2h after cardiopulmonary bypass and returned to baseline by 24h reperfusion. **p<.001 (B) Haptoglobin levels decreased from Start CPB during CPB and continued to fall for 24h after reperfusion. (* p<.05, **p<.001)
Figure 2.
Figure 2.
A. Contour plot that shows the effect of the interaction between the predictors, mean PaO2 and CPB duration, on the predicted probability of severe hemolysis (ΔPHb ≥ 50mg/dL). B.Scatter plot of mean PaO2 vs. CPB duration of all 100 subjects. Those with severe hemolysis depicted with closed red diamonds and those without by open blue circles.
See this image and copyright information in PMC

Comment in

References

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