Echocardiographic assessment of early circulatory status in preterm infants with suspected intrauterine infection.

OBJECTIVE

To assess early circulatory status in very low birthweight (VLBW) infants with suspected intrauterine infections.

PATIENTS: Thirteen VLBW infants who were diagnosed with prenatal infections because of raised serum IgM at birth (infectious group), and 39 infants matched for gestational age and birth weight (control group).

METHODS

Echocardiographic assessments were performed consecutively from birth to day 28 in all VLBW infants. Left ventricular output (LVO) and left ventricular stroke volume (LVSV) were measured using Doppler echocardiography. Pulsed Doppler assessment of pulmonary artery pressure (PAP) was performed using the corrected ratio of the pulmonary artery acceleration time to the right ventricular ejection time (AT/RVET(c)). Blood flow in the superior mesenteric artery (SMA) was also evaluated by Doppler ultrasound.

RESULTS

Mean LVO and LVSV were both significantly higher in the infectious group than in the control group at 12 hours (LVO; 188 v 154 ml/kg/min) and 72 hours (LVO; 216 v 173 ml/kg/min) of life. Pulsed Doppler assessment of PAP showed that mean AT/RVET(c) values were significantly lower in the infectious group than in the control group at 48 hours, 96 hours, day 14, and day 28. In the analysis of SMA flow velocities, both peak systolic velocities and time averaged velocities had decreased significantly in the infectious group compared with the control group at 24 hours, 36 hours, 96 hours, and day 28.

CONCLUSIONS

VLBW infants with suspected prenatal infection showed a unique circulation status, namely high cardiac output, latency of high PAP, and low organ flow.