Hemodynamics in preterm infants with late-onset sepsis

To describe the hemodynamic changes with time in preterm infants with clinical sepsis.

Blood pressure, right ventricular output (RVO), left ventricular output (LVO), and superior vena cava (SVC) flow of infants who had a suspected infection and showed signs of cardiovascular compromise were measured every 12 hours or until there was considered clinical improvement.

Twenty infants with a median gestational age of 27 weeks (range, 25-32 weeks) and weight of 995 g (range, 650-1980 g) were examined. Five patients died. The mean (SD) RVO, LVO, and SVC flow at the first measurement were 555 (133), 441 (164), and 104 (39) mL/kg/min, respectively. The calculated systemic vascular resistance (SVR) was 0.08 (0.04) mm Hg/mL/kg/min. There was no significant change in flow in the 15 surviving infants. Blood pressure and SVR increased from the first to the last measurement (mean difference: blood pressure, 8 mm Hg; 95% CI 3 to -13; systemic vascular resistance, 0.02 mm Hg/mL/kg/min; 95% CI, 0.01 to -0.04). Flows decreased and SVR increased in the 5 non-surviving infants (mean difference: RVO, -318 mL/kg/min; 95% CI, -463 to -174; LVO, -292 mL/kg/min; 95% CI, -473 to -111; SVC flow, -46 mL/kg/min; 95% CI, -77 to -16).

Preterm neonates with sepsis have relatively high left and right cardiac outputs and low SVRs. A decrease in RVO or LVO >50% compared with the initial measurement is associated with mortality.