Association between neutrophil-lymphocyte-ratio and oxygen delivery in patients after the Norwood operation

Abstract

Background Both neutrophil-lymphocyte-ratio and renal oxygen extraction have been demonstrated to be associated with adverse events after cardiac surgery. The association between neutrophil-lymphocyte-ratio and renal oxygen extraction has not previously been studies. The aim of this study was to characterize the association between neutrophil-lymphocyte ratio and renal oxygen extraction. Methods High fidelity hemodynamic monitoring data was retrieved for patients who underwent the Norwood operation. Bayesian regression analyses were conducted to identify what hemodynamic variables, including renal oxygen extraction, were associated with neutrophil-lymphocyte ratio. Results A total of 27,270 datapoints were collected over 1,338 patient-hours for nine unique patients. Renal oxygen extraction ratio had an area under the curve of 0.72 to identify renal oxygen extraction of over 35%. An increase in renal oxygen extraction by 1 was associated with a 0.15 increase in the neutrophil-lymphocyte-ratio. Conclusion In patients after the Norwood procedure, there is a correlation between the neutrophil-lymphocyte-ratio and renal oxygen extraction. A neutrophil-lymphocyte-ratio of greater than 2.95 has fair-performance in identifying renal extraction of greater than 35%.