Tehran University Medical Journal

Background: Umbilical cord blood gas analysis is a useful method for assessment of oxygenation and acid-base status in neonates. Severe fetal acidemia is associated with increased perinatal mortality and increased risk of subsequent impaired neurological development. Due to high percentage of C/S in our country and the effect of anesthetic medications on umbilical blood gases which can cause neonatal acidosis and hypoxemia, the study of umbilical cord blood gas in vaginal delivery versus cesarean section is mandatory.

Methods: In this cross-sectional study one hundred samples were taken from Mostafa Khomeini hospital in summer 2004. The samples were taken immediately of umbilical vein after clamping the umbilical cord and analyzed after 10 minutes. Cases were classified in to 3 groups: vaginal delivery (n=40), elective C/S under general anesthesia (n=35) and C/S under spinal anesthesia (n=25). Duration of anesthesia and its effect on blood gas and infants apgar were assessed.

Results: In the first group (vaginal delivery) mean blood gase parameters were pH=7.3064.73, pO2=25.246.87, HCO3=20.562.03, Apgar=8.820.38 and pCO2=41.826.57. In the second group (general anesthesia) mean blood gaze parameters were: pH=7.3044.73, pO2=38.7014.02, pCO2=43.265.87, HCO3=21.1113 and apgar score=8.170.7. In the third group (spinal anesthesia) mean blood gaze parameters were: pH=7.3014.50, pCO2=44.14.99, HCO3=21.382.15, pO2=26.625.5 and apgar=8.600.62. The apgar scores and pO2 demonstrated significant relationship with type of anesthesia. The apgar score was lower and pO2 was higher in C/S under general anesthesia compared with the other two groups. There was significant relationship between duration of anesthesia and umbilical pO With increasing duration of anesthesia, pO2 was reduced. Between the type of delivery and anesthesia duration with PH, pO2, pCO2 and HCO3 were not meaningful relationship (P<0.05).

Conclusion: There was no significant difference between type of delivery and umbilical blood gas parameters. Neonatal apgar score in NVD is higher than the other groups. With increasing duration of general anesthesia in C/S, umbilical po2 is reduced.

Background: The Biophysical Profile (BPP) is a noninvasive test that predicts the presence or absence of fetal asphyxia and, ultimately, the risk of fetal death in the antenatal period. Intervention on the basis of an abnormal biophysical profile result has been reported to yield a significant reduction in prenatal mortality, and an association exists between biophysical profile scoring and a decreased cerebral palsy rate in a given population. The BPP evaluates five characteristics: fetal movement, tone, breathing, heart reactivity, and amniotic fluid (AF) volume estimation. The purpose of study was to determine whether there are different degree of acidosis at which the biophysical activity (acute marker) are affected.

Methods: In a prospective study of 140 patients undergoing cesarean section before onset of labor, the fetal biophysical profile was performed 24h before the time of cesarean and was matched with cord arterial PH that was obtained from a cord segment (10-20cm) that was double clamped after delivery of newborn. (using cord arterial PH less than 7.20 for the diagnosis of acidosis).

Results: The fetal biophysical profile was found to have a significant relationship with umbilical blood PH. The sensitivity, specificity, positive predictive value, negative predictive value of fetal biophysical profile score were: 88.9%, 88.6%, 50%, 98.1%.

Conclusion: The first manifestations of fetal acidosis are nonreactive nonstress testing and fetal breathing loss in advanced acidemia fetal movements and fetal tone are compromised. A protocol of antepartum fetal evaluation is suggested based upon the individual biophysical components rather than the score alone.

Conclusion: The patients with a lower than normal pH, tracheal extubated at the discretion of the ICU anesthesiologist did not have a clinical outcome worse than that of the patients extubated in accordance with our routine institutional protocol.