Abstract
We tested the hypothesis that net L→R duct shunt contributes to PBF surge in premature lambs during the first hour of life (Pediat. Res., 8:433, 1974) and to high PBF seen later in lambs with severe HMD (Pediat. Res., 9:393, 1975). Total PBF, right ventricular output (RVO) and duct shunt were measured during first hours of life in 1 lamb with and 1 without HMD. At 129-130d gestation, a pre-calibrated electromagnetic flow transducer with non-occlusive zero was implanted on the main pulmonary artery (PA) to measure RVO; a similar transducer was implanted on the postductal portion of the common PA to measure PBF. Duct shunt was calculated as the difference between PBF and RVO. Lambs were returned to the amniotic cavity for 7-8d and then delivered by C-Section at 137d gestation. In each lamb, PBF rose sharply from < 50 to peaks of 487 and 473 ml/kg/min, respectively, at 22 and 29 min of age and then stabilized at lower levels by 1 hr of age. RVO stayed at high levels until after the PBF surge, then fell to stable levels by 1 hr of age. During the first 4 hr, net L→R duct shunt accounted for 28 to 68% of PBF (means 54 and 52%). These data suggest that L→R duct shunt contributes appreciably to PBF during the PBF surge and at age 1-4 hr. L→R duct shunt may be a major source of the high PBF previously reported in lambs with HMD.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Stinson, D., Allen, A., Macdonald, H. et al. 1236 CONTRIBUTION OF LEFT-TO-RIGHT (L→R) DUCTUS ARTERIOSUS SHUNTING (DUCT SHUNT) TO PULMONARY BLOOD FLOW (PBF) IN PREMATURE LAMBS WITH AND WITHOUT HYALINE MEMBRANE DISEASE (HMD) DURING THE FIRST HOURS OF LIFE. Pediatr Res 12 (Suppl 4), 570 (1978). https://doi.org/10.1203/00006450-197804001-01242
Issue Date:
DOI: https://doi.org/10.1203/00006450-197804001-01242