Use of NIRS to Detect Acute Kidney Injury in Preterm Infants

This prospective, single-center study was conducted at UnityPoint Health-Meriter Hospital (Madison, WI, USA) in preterm neonates admitted to a level III NICU from April 2018 to August 2019. The primary study aim was to assess changes in RrSO2 with continuous renal NIRS monitoring to detect AKI during the first 7 days of age.

The INVOS 5100 C (Somanetics, Troy, MI, USA) four channel NIRS monitors were used to measure RrSO2 (measured at the right or left flank) and Cerebral regional Somatic tissue Oxygenation (CrSO2; measured at the forehead) for all neonates. At each measurement site, for skin protection, subjects had a transparent Mepitel (with Safetac Technology, Norcross, GA) adhesive dressing placed with the adhesive neonatal NIRS sensor (INVOS OxyAlert NIRSensor, Covidien) adhered over the Mepitel dressing. Neither cerebral or kidney sensors were placed with ultrasound guidance. Tissue oxygenation was recorded every 3 seconds until 7 days of age, and the sensor was changed one time when the patient reached three to four days of age per the company's recommendation. There were no restrictions on positioning or handling of neonates; nurses re-positioned neonates every 3-6 hours per unit protocol to prevent skin pressure injuries. Researchers, staff, and parents were blinded to RrSO2 values.