Indomethacin impairs coronary perfusion in infants with hemodynamically significant ductus arteriosus.

BACKGROUND: A haemodynamically significant ductus arteriosus (HSDA) is commonly associated with morbidity in preterm infants. AIM: To study the effect of the first dose of indomethacin on coronary blood flow in preterm neonates diagnosed with an HSDA. METHOD: A prospective observational echocardiographic study was performed on preterm infants. A single study dose of intravenous indomethacin (0.1 mg/kg) was administered over 1 h. Serial echocardiography was performed before and after indomethacin treatment to study the effect on coronary artery perfusion and cardiovascular performance. RESULTS: Eighteen infants born at a median gestation of 25.8 (24.2, 28.1) weeks and a birth weight of 773 g (704, 1,002) were evaluated. The median age at indomethacin administration was 7.5 days (4, 17). There was no significant change in arterial pressure or ventilatory indices. Left anterior descending artery diastolic velocity and time integral declined from 0.3 ± 0.1 and 3.19 ± 1.2 m/s to 0.22 ± 0.08 and 2.01 ± 0.9 m/s, respectively, within 10 min of completion of infusion. These indices showed partial recovery when reassessed after 60 min. There were no changes in left ventricular output or transductal flow. CONCLUSIONS: Intravenous indomethacin was followed by a decline in coronary arterial diastolic blood flow.

Congenital tuberculosis after in-vitro fertilisation.

A 6-week old infant who had been conceived through in-vitro fertilisation (IVF) presented with a skin lesion and enlarged lymph nodes, and developed severe respiratory distress. Mycobacterium tuberculosis was identified; his mother was the only potential source identified. To our knowledge, this is the first case of congenital tuberculosis after IVF reported in Australia and the second worldwide. It highlights the importance of adequate screening during investigation of infertility and the difficulties in diagnosing congenital tuberculosis.

Velocity and attenuation of sound in the isolated fetal lung as it is expanded with air.

We measured the velocity and attenuation of audible sound in the isolated lung of the near-term fetal sheep to test the hypothesis that the acoustic properties of the lung provide a measure of the volume of gas it contains. We introduced pseudorandom noise (bandwidth 70 Hz-7 kHz) to one side of the lung and recorded the noise transmitted to the surface immediately opposite, starting with the lung containing only fetal lung liquid and making measurements after stepwise inflation with air until a leak developed. The velocity of sound in the lung fell rapidly from 187 +/- 28.2 to 87 +/- 3.7 m/s as lung density fell from 0.93 +/- 0.01 to 0.75 +/- 0.01 g/ml (lung density = lung weight/gas volume plus lung tissue volume). For technical reasons, no estimate of velocity could be made before the first air injection. Thereafter, as lung density fell to 0.35 +/- 0.01 g/ml, there was a further decline in velocity to 69.6 +/- 4.6 m/s. High-frequency sound was attenuated as lung density decreased from 1.0 to 0.5 g/ml, with little change thereafter down to a density of 0.35 +/- 0.01 g/ml. We conclude that both the velocity of audible sound through the lung and the degree to which high-frequency sound is attenuated in the lung provide information on the degree of inflation of the isolated fetal lung, particularly at high lung densities. If studies of sound transmission through the lung in the intact organism were to confirm these findings, the acoustic properties of the lung could provide a means for monitoring lung aeration during mechanical ventilation of newborn infants.