G212(P) Splanchnic near infra-red spectroscopy: a reliable clinical tool?. (May 2019) - Seager, E
Abstract : Aims: To systematically review the literature (from 2005–2018) in order to determine whether near infra-red spectroscopy (NIRS) can be a reliable valid clinical tool on the neonatal unit in monitoring gut oxygenation. Methods: PubMed database was searched using the terms 'neonate', 'preterm infants', 'NIRS' and 'gut oxygenation'. Abstracts not in English and not relevant to gut oxygenation were removed; the remaining articles were then analysed. Results: We reviewed 29 studies interrogating the validity of abdominal NIRS and its potential clinical application in neonates; demonstrating that NIRS may be a useful clinical tool in monitoring of gut oxygenation in newborn infants. In normal neonates, there was strong correlation between splanchnic regional oxygenation (rSO2 ) and systemic mixed venous saturation (r=0.89, p<0.0001), gastric pH (r=0.79, p<0.0001) and serum lactate (r=0.77, p<0.0001). We found several observational studies that demonstrated how NIRS could be used in clinical practice. Cerebro-splanchnic oxygenation ratio (CSOR) was thought to be highly predictive of intra-abdominal pathology such as necrotising enterocolitis (NEC). Splanchnic rSO2 were significantly associated with change in SMA velocity reflecting changes in blood flow in the SMA in response to feeds; infants with feed intolerance had lower rSO2 (p=0.0043) and CSOR (p=0.03) compared to those with normal feed tolerance. Correlation between intestinal fatty acid binding protein (iFABP), a marker of intestinal injury and splanchnic oxygenation markers has also been reported. There are reports of greater fluctuation of the rSO2 above and below pre-transfusion baseline levels in those infants who went on to develop NEC post-transfusion. Conclusion: This review demonstrates NIRS may prove to be a useful, non-invasive bedside tool on the neonatal unit to directly measure gut perfusion and oxygenation, better informing clinical management. Further research into normal values in different neonatal populations may facilitate NIRS use routinely in neonatal units. We recommend large observational studies and randomised controlled trials looking at specific measurements and cut offs for abdominal NIRS for clinical decisions eg. blood transfusion, feeding and early detection of sepsis and NEC.