(12) Current State of Renal NIRS Monitoring in the NICU: Results from a CHNC Survey

Matthew Harer, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Jennifer Rumpel, University of Arkansas for Medical Sciences, United States; Brianna Liberio, Indiana University School of Medicine, United States; Khodayar Rais-Bahrami, Children's National Hospital, Washington, DC, United States; Mona Khattab, Baylor College of Medicine / Texas Children's Hospital, Houston, TX, United States; Cara L. Slagle, Cincinnati Children’s hospital, Cincinnati, OH, United States; Suma B. Hoffman, Children’s National Hospital/GWU, United States; Sofia Perazzo, Children's National Hospital, Armed Forces - AE, United States; Christine Stoops,

Background: Near infrared spectroscopy (NIRS) monitoring of regional tissue oxygenation is becoming more common in neonates. As a non-invasive technique, it is preferred over invasive measures like blood draws in this population. Although it is being used more frequently in research studies in the NICU to detect renal hypoxia prior to acute kidney injury (AKI), it is unclear how or why it is being used clinically.

Objectives: To determine the current state of clinical renal NIRS monitoring in neonatal intensive care units (NICUs) in the United States.

Design/Methods: We conducted an online IRB approved survey of Children’s Hospital Neonatal Consortium (CHNC) member sites in 2022. The 22-question survey was developed by Neonatologists and Pediatric Nephrologists who belong to the NIRS subgroup of the CHNC Kidney Focus Group. The survey was piloted and tested before being sent out to the lead Neonatologist at all member sites. Two reminder emails were sent, and the survey closed two weeks after being sent out.

Results: 34 out of 45 sites (75%) completed the survey. 29 of these sites are academic centers, 10 are a part of the Neonatal Kidney Collaborative, and 25 NICUs care for pre-operative congenital heart disease (CHD) neonates. A total of 26 sites (76.5%) have NIRS monitors available for clinical use with 24 sites using INVOS/Medtronic monitors. Figure 1 shows the number of monitors available at each site’s NICU. NIRS monitoring is utilized only for clinical purposes at 12 sites (46%) and for both clinical and research purposes at 14 (54%) sites. Recorded values and parameters are integrated into the medical record at 10 sites while Figure 2 shows how frequently nurses record values at the other 16 sites. The three most common indications for renal NIRS monitoring were CHD, ECMO, and congenital diaphragmatic hernia (Figure 3). 80% of sites discuss renal oxygenation on rounds while only five have a protocol or guideline to utilize renal oxygenation values. The most cited limiting factors for use of NIRS were unclear normative values and unclear how to utilize in clinical practice (Figure 4).

Conclusion: Monitoring of kidney oxygenation with renal NIRS monitoring in critically ill neonates is common across CHNC NICU’s. Further work is needed to define normal values and develop optimal protocols to improve clinical care and potentially prevent comorbidities like AKI. Technological advances, like integration into the medical record, could ease the burden on nurses to document NIRS values.