الفهرس 
Introduction Aim of the workOnly 14 pages are availabe for public view
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Abstract
The study population was recruited from tertiary neonatal intensive care unit at the Section of neonatal and pediatric critical care, Department of Pediatrics and Adolescence Medicine, Ulm University hospital, Ulm, Germany over a period of 18 months from October 2012 to June 2014. The study included 31 premature infants with clinical sepsis with a median gestational age 25.7 weeks and a median birth weight of 730 g. The study also included 25 preterm infants without clinical manifestations suggestive of neonatal sepsis as a control group. They were matched with cases for gestational age, birth weight, and age and weight at study entry.
This study aimed to investigate the hemodynamic response in newborn infants to neonatal sepsis through estimation of central hemodynamic changes represented in left ventricular output, right ventricular output, and superior vena cava flow measurements by echocardiography Doppler; and peripheral hemodynamic changes represented in cerebral, intestinal, and renal blood flow assessed by pulsed Doppler and/or near infrared spectroscopic estimation of regional tissue oxygenation.
In this study arterial blood pressure showed no significant with no significant difference between cases and controls and within the cases before and after improvement. These findings might indicate that some compensatory mechanisms have maintained stable blood pressure by changes in its determinants (cardiac output and systemic vascular resistance). The pH was significantly lower and base deficit was significantly higher in the cases before than after improvement. In this work there were no differences in SpO2 and pCO2 in cases before and after improvement, so the difference in the acid base balance may indicate decreased perfusion in the cases which improved over time,
Central hemodynamic evaluation revealed a higher left ventricular output and lower systemic vascular resistance in cases than in controls. The heart rate, showed no significant difference between cases and controls. This indicates that the difference in the left ventricular output was not due to difference in heart rate, but rather due to difference in stroke volume. Right ventricular output was also higher in non-PDA cases than in controls. This difference in right ventricular output was not found in cases with PDA. Superior vena cava flow showed no significant difference between cases and controls and in cases over study phases.
Peripheral hemodynamics showed increased cerebral blood flow in cases represented by lower resistance to blood flow and higher regional cerebral oxygen saturation. There was also increased intestinal blood flow represented by lower resistant to blood flow in the early measurements and in cases compared with controls. Renal blood flow assessed by measuring the regional renal tissue oxygen saturation, showed no differences between cases and controls nor over study phases. This may be due to the more dependency of neonatal kidney on the local production of vasodilatory prostaglandins. It was obvious from the results of our study that the presence of a PDA can disturb the peripheral hemodynamic response to infection.
In conclusion, this study revealed that preterm infants with suspected late onset neonatal sepsis showed increased cardiac output associated with decreased systemic vascular resistance and increased intestinal and cerebral perfusion. These valuable information which can be obtained by functional echocardiography, Doppler studies, and near infrared spectroscopy should be used more frequently in clinical practice in addition to arterial blood pressure for evaluation of circulatory adequacy and organ perfusion. Future studies are recommended to evaluate the influence of applying these techniques on the choice of different inotropic agents and on the short term and long term outcome.
Recommendations
1. Training courses about the evaluation of neonatal hemodynamics should be offered to clinicians dealing with sick newborns, together with how to use these information to change the management plans.
2. Trained personnel and special equipment for evaluation of neonatal hemodynamics should be available at least in tertiary neonatal intensive care units.
3. Future studies are recommended for further confirmation of the results of this study at different gestational ages, birth weights, and locations with different pattern of organisms.
4. Randomized controlled trials should be run to evaluate the choice between different inotropes based on the hemodynamic evaluation by functional echocardiography and its effect on the short term and long term outcome of sick newborns.