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pH effects on cardiac function and systemic vascular resistance in preterm infants
Shahab Noori1, Tai-Wei Wu, Istvan Seri
1Division of Neonatology and the Center for Fetal and Neonatal Medicine, Department of Pediatrics, Children's Hospital Los Angeles and the LAC+USC Medical Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90027, USA. snoori@chla.usc.edu
The Journal of Pediatrics
|November 21, 2012
Summary
In preterm infants, cardiac contractility is not significantly affected by acidosis in the first two weeks. However, systemic vascular resistance changes with pH after the initial transitional period.
Area of Science:
- Neonatal Physiology
- Cardiovascular Research
- Acid-Base Balance
Background:
- Acidosis in preterm infants can impact cardiovascular function.
- Understanding these effects is crucial for neonatal care.
Purpose of the Study:
- To investigate the relationship between arterial pH and cardiac function.
- To examine the effect of pH on systemic vascular resistance (SVR) in preterm neonates.
Main Methods:
- Prospective observational study of hemodynamically stable preterm infants (≤ 30 weeks' gestation).
- Echocardiography assessed cardiac function alongside blood gas analysis.
- Data analyzed for transitional (days 1-3) and post-transitional (days 4-14) periods.
Main Results:
- No linear relationship between pH and cardiac contractility (shortening fraction, stress-velocity index) was observed.
- A weak negative linear relationship between pH and left ventricular output was found in the post-transitional period.
- A positive linear relationship between pH and SVR was identified in the post-transitional period.
Conclusions:
- Myocardial contractility in preterm neonates is relatively resistant to acidosis in the first two weeks.
- Systemic vascular resistance response to acidosis matures rapidly after the transitional period.
- Arterial CO2 levels demonstrated similar effects to pH on myocardial function.
