Background Near infrared spectroscopy (NIRS) is evolving into a clinical monitorization method providing information regarding not only cerebral but abdominal or renal tissue oxygenation (rSO2) as well. Fractional tissue oxygen extraction (FTOE) is calculated from NIRS measurements and arterial haemoglobin oxygen saturation (SpO2) measured by pulse oxymeter. Multichannel NIRS devices maybe very helpful in newborns with multisystem problems enabling realtime simultaneous measurements of rSO2 from different parts of the body. Pulse oxymeter integrated into a multichannel NIRS device provides simultaneous SpO2 monitoring making FTOE calculations more accurate and easier.
Methods Three term newborns; 2 undergoing therapeutic hypothermia for hypoxic ischaemic encephalopathy grade II, 1 with critical pulmonary stenosis before and after cardiac surgery were monitored by multichannel NIRS (Sensmart X-100, NONIN, USA) device including cerebral, abdominal, renal rSO2 and SpO2 probes. FTOE was calculated using the equation; (SpO2-rSO2)/SpO2.
Results Duration of monitorization and rSO2 and FTOE values of different body sites are presented in table with mean±SD.
Discussion Longterm simultaneous monitoring of tissue oxygenation in brain, abdomen and kidneys is useful while following newborns with multisystem problems requiring hypothermia or circulatory medications to titrate the treatment accordingly. NIRS device with integrated pulse oxymeter maybe helpful for realtime calculation of FTOE to assess hemodynamics.