Cerebral Haemodynamic Changes by Red Blood Cell Transfusion in Neonates

Cerebral Haemodynamic Changes by Red Blood Cell Transfusion in Neonates

The timing and the indications for red blood cell (RBC) transfusions remain one of the most controversial topic in Neonatology. Indeed, biomarkers routinely used to discriminate between patients that will benefit from RBC transfusion appear insufficient. Tissue oxygenation could be useful to determine the need for transfusion.

This study aims to assess the effects of RBC transfusion on cerebral haemodynamics and oxygenation in neonates with a new hybrid optical device (BabyLux) integrating time-resolved spectroscopy (NIRS-TRS) and diffuse correlation spectroscopy (DCS).

It is hypothesized that cerebral blood flow decreases after RBC transfusion, whereas cerebral oxygenation and oxygen metabolism are unchanged.

The BabyLux hybrid setup can determine the following parameters in the same tissue sample non-invasively and continuously with a high temporal resolution (0.1-0.2 Hz):

• Cerebral blood flow index (CBFi), i.e. an index that is proportional with CBF
• Concentration of oxyhaemoglobin (O2Hb)
• Concentration of deoxyhaemoglobin (dHb)
• Total haemoglobin concentration (tHb)
• Tissue oxygen saturation (rStO2)
• Cerebral metabolic rate of oxygen index (CMRO2i), i.e. an index that is proportional with CMRO2 Hence, the BabyLux device allows assessment of key parameters of cerebral haemodynamics and, in particular, to examine if the percentage change of cerebral metabolic rate for oxygen is close to the expected zero, as an external quality control of the separate NIRS parameters.

There are no studies on RBC transfusion in neonates evaluating cerebral haemodynamic utilizing DCS and TRS combined.

Hence, primary aim of this study is:

- to assess the effect of RBC transfusion on cerebral haemodynamics and oxygenation as measured by the Babylux device.

Secondary aims are:

• to quantify the effect of estimated ∆[Hb] on the differential path length factor (DPF);
• to compare two different NIRS devices and techniques. BabyLux measurement will be performed before and after RBC transfusion, whereas during RBC transfusion cerebral oxygenation will be monitored with a spatially resolved continuous wave (CW) NIRS.

Inclusion Criteria:

• RBC transfusion prescribed according to local NICU guidelines
• Corrected age < 4 weeks corrected age
• Signed informed consent

Exclusion Criteria:

None