|
|
||||||||
1 Department of Pediatrics,
The purpose of this study was to characterize postnatal changes in regional Doppler blood flow velocity (BFV) and cardiac function of very-low-birthweight infants and to examine factors that might influence these hemodynamic changes. Mean and end-diastolic BFV of the middle cerebral and superior mesenteric arteries, cardiac output, stroke volume, and fractional shortening were measured in 20 infants birthweight 1,002 ± 173 g, gestational age 28 ± 2 wk) at 6, 30, and 54 h after birth and before and after feedings on days 7 and 14. Postnatal increases in cerebral BFV, mesenteric BFV, and cardiac output were observed that were not associated with changes in blood pressure, hematocrit, pH, arterial PCO2, or oxygen saturation. The postnatal pattern of relative vascular resistance (RVR) differed between the cerebral and mesenteric vasculatures. RVR decreased in the middle cerebral but not the superior mesenteric artery. Physiological patency of the ductus arteriosus did not alter postnatal hemodynamic changes. In response to feeding, mesenteric BFV and stroke volume increased, and mesenteric RVR and heart rate decreased. Postprandial responses were not affected by postnatal age or the age at which feeding was initiated. However, the initiation of enteral nutrition before 3 days of life was associated with higher preprandial mesenteric BFV and lower mesenteric RVR than was later initiation of feeding. We conclude that in very-low-birthweight infants over the first week of life 1) systemic, cerebral, and mesenteric hemodynamics exhibit region-specific changes; 2) asymptomatic ductus arteriosus patency and early feedings do not significantly influence these postnatal hemodynamic changes; and 3) cardiac function adapts to increase local mesenteric BFV in response to feedings.
Doppler blood flow velocity; brain; intestine; patent ductus arteriosus; antenatal steroid; enteral nutrition
This article has been cited by other articles:
![]() |
M. J. Stark, V. L. Clifton, and I. M.R. Wright Carbon Monoxide is a Significant Mediator of Cardiovascular Status Following Preterm Birth Pediatrics, July 1, 2009; 124(1): 277 - 284. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. McCurnin and R. I. Clyman Effects of a Patent Ductus Arteriosus on Postprandial Mesenteric Perfusion in Premature Baboons Pediatrics, December 1, 2008; 122(6): e1262 - e1267. [Abstract] [Full Text] [PDF] |
||||
![]() |
M J Stark, V L Clifton, and I M R Wright Microvascular flow, clinical illness severity and cardiovascular function in the preterm infant Arch. Dis. Child. Fetal Neonatal Ed., July 1, 2008; 93(4): F271 - F274. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. L. Kearns, S. M. Abdel-Rahman, S. W. Alander, D. L. Blowey, J. S. Leeder, and R. E. Kauffman Developmental Pharmacology -- Drug Disposition, Action, and Therapy in Infants and Children N. Engl. J. Med., September 18, 2003; 349(12): 1157 - 1167. [Full Text] [PDF] |
||||
![]() |
American Society for Parenteral and Enteral Nutrit Guidelines for the Use of Parenteral and Enteral Nutrition in Adult and Pediatric Patients JPEN J Parenter Enteral Nutr, January 1, 2002; 26(1_suppl): 1SA - 138SA. [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |