The Relationship between blood pressure parameters and left ventricular output in neonates

Objective To evaluate the relationship between systolic (SBP), diastolic (DBP), mean (MBP) blood pressures and pulse pressure (PP), and left ventricular output (LVO), a surrogate of systemic blood flow. Study design This retrospective study included neonates who underwent targeted neonatal echocardiography (TNE) in 3-tertiary NICUs over 2 years. Associations between LVO and BP components were investigated. Analysis was adjusted for relevant covariates. Result 1060 studies from 485 neonates were included, with a mean GA of 28.4 +/- 4.6 weeks and birth weight of 1234 +/- 840 grams. LVO was associated positively with SBP and PP, and negatively with GA. PP demonstrated the highest predictive value for identifying infants with LVO < 150 ml/kg/min (area under the curve 0.75 [95% CI 0.68, 0.82]). MBP and DBP demonstrated no correlation with LVO. Conclusion BP parameters correlate poorly with LVO, irrespective of GA and underlying etiology. Narrow PP may be more reflective of low LVO than low SBP.