الفهرس 
PATENT DUCTUS ARTERIOSUSOnly 14 pages are availabe for public view
 |  | from | 263 |  |  |
| | | from | 263 | | |
Abstract
Isolated patent ductus arteriosus (PDA) occurs approximately once in 2500 to 5000 live births. The incidence increases greatly with prematurity and with decreasing birth weight. However, preterm infants with RDS have a higher incidence of PDA especially those with respiratory failure requiring assisted ventilation.
Patent ductus arteriosus is not only more frequent among premature infants, but is also less-well tolerated. PDA affects the cerebral perfusion, and this may increase the risk for IVH in preterm infants especially those with birth weight <1500gm and or gestational age <32 weeks
In the present study we tried to determine the incidence of IVH in mechanically ventilated preterm infants who have a hemodynamically significant ductal shunt as proved by Echocardiographic examination. The study also assesses the effect of different risk factors on this incidence.
This prospective case control study was conducted on 150 preterm infants ≤32 weeks gestation, recruited from neonatal intensive care unit of maternity hospital, Kuwait University, in the period from January 2000 to August 2001.
The study was divided into 3 parts, In part 1 we studied the incidence of IVH in the studied population and its correlation with some perinatal risk factors, in part II we tried to find the relationship between IVH and PDA and in part III we tried to find a correlation between PDA and the severity of IVH.
The data we got from Part I of this study indicated that the overall incidence of IVH in the studied unit is 32%; we could prove that the incidence of IVH increased with both decreasing birth weight and gestational age. from the maternal variables we studied we could appreciate only the border line effect of pregnancy-induced hypertension (PIH) on IVH incidence. (Both the incidence as well as severity of IVH were lower in infants born to mothers with PIH).
The present study also demonstrated that CS protects the VLBW infants against IVH. Infants with IVH were found to be appropriate for GA when compared with the non-IVH group. Also, the low admission temperature of the preterm infants was proved to increase the risk of IVH in this group.
Another important factor found to affect adversely the IVH incidence was the low blood pH (Acidosis) on admission. Therapy variables (Inotropes and volume expanders) to treat hypotension and hypovolemia were other important risk factors increasing the incidence of IVH.
In the present study, a significant association was found between severe RDS (Represented by the higher FIO2 and the higher PIP together with the need for >1 dose of surfactant) and IVH incidence.
Also we found that multiple doses of surfactant therapy would increase significantly the incidence of IVH, but this may be directly related to the severity of RDS and not to the surfactant therapy.
In Part II we could detect a clear association between PDA and IVH in the presence of other variables as there was a significant association between the hemodynamically significant PDA and IVH. Ductal diameter was found to be slightly larger in the IVH group than in the non-IVH group.
Also, Indomethacin therapy used for ductal closure was proved to be significantly associated with higher incidence of IVH, but this is probably related to the presence of PDA and not directly related to Indomethacin treatment.
In part III we studied the factors which contributed to the severity of IVH within the PDA group. We proved that maternal APH contributed to the severity of IVH within the cases of PDA. Also antenatal Steroids were proved to reduce the severity of IVH.
Gestational age and weight didn’t contribute to the severity of IVH in the PDA group, as there was no difference in gestational age or weight between the two groups of IVH (mild and severe) within the PDA +ve infants. This will add to our conclusion that the severity of IVH is related directly to PDA and not to the gestational age or weight of the infants.
The 9 Infants with the severe form of IVH were hypotensive, and in need for Inotropes and volume expanders. This signifies the importance of the low blood pressure of the preterm infants as a risk factor for both IVH incidence and severity.
Seizures were also found to be more in cases with the severe forms of IVH, but whether it was a result or a cause for the severe grades of IVH, is still questionable.