Background Diagnosing circulatory failure in preterm infants with sepsis is challenging. Multisite Near-infrared spectroscopy (NIRS) monitoring and functional echocardiography are non-invasive tools to assess micro- and macro circulation. Our aim was to assess the correlation between both monitoring methods in preterm infants with clinical sepsis.
Methods Prospective exploratory cohort study. We included preterm infants with clinical sepsis. Functional echocardiography was performed twice, once within 48 h of sepsis work-up and once at least 24 h later. We measured cerebral, renal, and intestinal tissue oxygen saturation using NIRS during an hour of stable measurements directly preceding or following echocardiography and calculated fractional tissue oxygen extraction (FTOE) in each tissue. We determined Spearman’s correlation coefficients between the FTOE and right ventricular output (RVO), left ventricular output (LVO), superior vena cava flow (SVC-flow), ductus arteriosus flow (DA-flow) and patent foramen ovale flow (PFO-flow).
Results We included 24 infants (median GA=27.7 wks, BW=928g, PNA=11.8d). In seven infants only the first echocardiography was performed. Correlation coefficients between (changes in) NIRS-measurements and (changes in) functional echocardiography measurements are displayed in Table 1.
Conclusion RVO-PFO and LVO-DA flow, indicators of systemic blood flow in preterm infants with shunts, were negatively associated with intestinal FTOE, but not with renal and cerebral FTOE. This indicates that a compromised macro circulation in preterm infants with clinical sepsis is associated with low intestinal but not cerebral or renal perfusion. Furthermore, our results suggest that macro circulatory changes during sepsis do not co-occur with changes in microcirculatory indices in various organs.