Authors
Ceri Murphy, Jayanta Banerjee, Terence Leung, Narendra Aladangady

Institution(s)
1.Homerton University Hospital NHS trust, London, UK 4.Imperial College London, London, UK
2.Queen Mary University of London, London, UK 5.University College London, London, UK
3.Imperial College Healthcare NHS Trust, London, UK

Introduction
Blood transfusion (BT) improves cerebral1 and gut2 tissue perfusion in preterm infants. Retrospective and cohort observational studies have indicated that pre-existing anaemia as well as BT may lead to necrotising enterocolitis.3 The objective of this study was to measure the relative changes in cerebral and splanchnic tissue oxygenation following blood transfusion using Near Infra-Red Spectroscopy (NIRS) in preterm infants.

Methods
Preterm infants with clinical indication for BT were studied; pre-existing Grade 3 or 4 IVH or gut abnormality were excluded. Infants were recruited to three postnatal age groups: 1-7 (group 1); 8-28 (group 2) and ≥29 days of life
(group 3). Simultaneous cerebral and gut tissue oxygenation index (TOI) and fractional tissue oxygen extraction (FTOE) were measured using NIRS 15 minutes before, during and 15 minutes post-BT. Descriptive analysis and t-tests were performed using SPSS 22.0. Ethical approval and parental consent were obtained.

Results
A total of 59 preterm infants receiving transfusion were recruited to the three postnatal age groups: Group 1; n=20, Group 2; n=21 and Group 3; n=18. The median (range) gestational ages were 26 (23 – 27), 25 (23 – 30) and 26 (24 – 34) weeks and birth weight 763 (600 – 1180), 740 (600 – 1240) and 793 (520 – 1746) grams for the respective postnatal age groups. The cerebral TOI increased significantly (p<0.05) by 5%, 11% and 12% following blood transfusion in Group 1, Group 2 and Group 3 respectively; whilst splanchnic TOI increased significantly (p<0.05) by 42%, 29% and 30% in those postnatal age groups respectively. Both the cerebral and splanchnic FTOE decreased after blood transfusion in all groups but more so in the splanchnic tissue. On multivariate analysis, changes in TOI following blood transfusion were not associated with PDA, feeding and pretransfusion Hb.

Conclusions
The results indicate that the improvement of splanchnic tissue oxygenation following transfusion was more pronounced compared to cerebral oxygenation. This could be an adaptive mechanism of reduced splanchnic tissue perfusion in response to anaemia and sparing of brain perfusion.

References
(1)Banerjee J, Leung T and Aladangady N. Early Hum Dev, 2016; (2)Banerjee J, Leung T, and Aladangady N.Vox Sang, 2016. & (3)Patel R.M., et al. JAMA, 2016.