0018

THE CORRELATION BETWEEN GASTROINTESTIONAL AND RENAL HEMODYNAMIC CHANGES IN ASPHYXIATED NEONATES

Liu J, Cao HY

Department of Pediatrics, Beijing Yanhua Hospital, Beijing, China

 

Objective: Newborn infants with asphyxia are believed to be at increased risk of having necrotizing enterocolitis and renal dysfunction because of a hemodynamic disturbance in the splanchnic and renal circulation. The purpose of this study was to correlate the severity of the gastrointestinal tract and the kidneys that are particularly .

Methods: Thirty term neonates with both blood pH<7.30 and a 1-minute Apgar score6 and twenty-five healthy newborn infants were enrolled in this study. All asphyxiated neonates were studied with in 24 hours. We used an Ultramark-9 color and duplex doppler unite with a 6.0 MHz sector probe to insonate the superior mesenteric artery (SMA) and renal artery (RA) at an angle as close to zero as possible to measure their blood flow velocity profiles. For each vessels the peak systolic flow velocity (PSFV,cm/s), end-diastolic flow velocity (EDFV,cm/s), time-averaged mean velocity (TAMV,cm/s) were determined. In addition, resistance index (RI) and pulsatility index (PI) were determined automatically by the built-in software of the system .

Results: (1)The hemodynamic parameter change of SMA in neonates with birth asphyxia and health controls was respectively: RSFV (55.0±15.4)cm/s vs (92.1±14.1) cm/s, EDFV(5.6±5.1) cm/s vs (26.7±5.7) cm/s, TAMV (26.4±9.7) cm/s vs (41.0±6.2) cm/s, PI (1.97±0.38) vs (1.67±0.22), RI (0.89±0.09) vs (0.75±0.05) (p<0.01). (2)The hemodynamic parameter changes of RA in neonates with birth asphyxia and health controls was respectively: PSFV(24.6±7.1) cm/s vs (47.5±9.5) cm/s, EDFV (4.1±1.3) cm/s vs (14.8±3.4) cm/s, TAMV (9.6±3.9) cm/s vs (27.4±6.4 ) cm/s, PI (2.12±0.36) vs (0.82±0.04), RI (1.19±0.11) vs (0.68±0.04) (p<0.01). (3)The reduced degree of EDFV were 70 in kidneys and 80 in SMA respectively,six of SMA had absent diastolic flow in the SMA. (4)In the study, all the babies were restudied every 24 hours until the profile returned to normal,the persistent abnormal SMA doppler findings in one-third of neonates at <7 days and two-third at >7days and even some of them until after 1214 days of age, while the RA abnormal doppler findings returned to normal within 7 days.

Conclusion: (1)The gastrointestinal tract is believed to be particularly vulnerable to hemodynamic perturbation as a result of perinatal hypoxemia. This could result in bowel ischemia as an antecedent of necrotizing enterocolitis. (2)Although both kidney and intestinal tract are non-living organs, the reduced degree of blood perfusion of kidneys was less than that of intestinal tract ,which will help to preserve the renal function.