Partial exchange transfusion results in increased cerebral oxygenation and faster peripheral microcirculation in newborns with polycythemia

Abstract

Aim: The aim of this study was to assess cerebral and peripheral oxygenation, by using near infrared spectroscopy (NIRS) and microcirculation by using side stream dark field (SDF) imaging in newborns with polycythemia before and after partial exchange transfusion (PET) therapy to investigate treatment effect on tissue oxygenation and microcirculation.

Methods: Polycythemic newborns with venous haematocrit (Htc) >70% or ≥65% with symptoms were included. NIRS measurements for cerebral and peripheral oxygenation and SDF recordings for microcirculatory flow assessment were obtained before and after PET. Fractional tissue oxygen extraction (FTOE) was calculated based on tissue oxygenation index and oxygen saturation. Wilcoxon test was used for statistical analysis.

Results: Fifteen newborns were included. Cerebral tissue oxygenation index, microvascular flow index and % of vessels with hyperdynamic flow increased after PET; median (range): 61.27 (51.36-61.87) versus 64.54 (54.1-74.38), 2.74 (2.46-3) versus 3.22 (2.64-3.75) and 0 (0-2.8) versus 3 (0-99.3), respectively. Whereas cerebral fractional tissue oxygen extraction (CFTOE), % of vessels with sluggish flow decreased after treatment; 0.36 (0.22-0.44) versus 0.31 (0.17-0.46), 1.4 (0-69) versus 0 (0-0.9), respectively. Peripheral oxygenation was unchanged.

Conclusion: Partial exchange transfusion improves microcirculation in polycythemic newborns. Cerebral oxygenation increases and cFTOE decreases suggesting increased blood flow. Microvascular flow increases possibly representing reactive hyperperfusion after hemodilution. Whether these effects are beneficial require further research.