morphine and Hemolysis

The degree of fluorescence polarization (P value) of 1,6-diphenyl-1,3,5-hexatriene has been shown to be an excellent indicator of the lecithin/sphingomyelin (L/S) ratio in laboratory prepared liposomal dispersions. In order to test the validity of this technique in amniotic fluid, the L/S ratio and P value of 161 amniotic fluid specimens were determined. In 127 the P value was less than or equal to 0.336 and the L/S ratio was greater than or equal to 2. In 26 the P value was greater than 0.336 and the L/S ratio was less than 2 (P less than 0.05). The amniotic fluid P value is affected by blood or meconium but not by surgical lubricants or bilirubin. We concluded that the degree of fluorescence polarization of amniotic fluid indicates fetal lung maturity as reliably as the L/S ratio. However, this method has important technical and practical advantages that make it more applicable for a clinical laboratory.

Topics: Amniotic Fluid; Blood; Female; Hemolysis; Humans; Liposomes; Lubrication; Lung; Meconium; Phosphatidylcholines; Polyenes; Pregnancy; Spectrometry, Fluorescence; Sphingomyelins; Viscosity

Amniotic fluid samples for physiologic maturity tests are frequently (15 to 20%) contaminated with blood and/or meconium. The effects of this contamination on the lecithin/sphingomyelin ratio is well known. However, less is known about the effect of blood and meconium on the rapid surfactant test. Additionally, because the RST may be performed in the office or at bedside, there is the possibility of temperature affecting the result. Therefore, the effects of blood, meconium, and temperature on the rapid surfactant test have been investigated. Contamination with blood or meconium may result in a false indication of fetal maturity. However, the test may still provide useful information concerning pulmonary status of the fetus, if the rapid surfactant test is intermediate or immature despite contamination. Temperature also affects the reliability of the rapid surfactant test. The test is found to be most reliable in the range of 20 to 30 C (with higher temperatures the bubbles dissipate more rapidly; with lower temperatures the foam is more stable).

Topics: Amniotic Fluid; Blood; Female; Fetal Blood; Hematocrit; Hemolysis; Humans; In Vitro Techniques; Infant, Newborn; Lung; Meconium; Pregnancy; Pulmonary Surfactants; Temperature

The surface properties of the amniotic fluid were determined in 96 normal pregnancies between weeks 23 and 41. The y-max, y-min, hysteresis areaa, and stability index were used as parameters for evaluation of the surface tension are diagrams. These results were plotted against the gestation week and a curve for the normal course of surface tension of the amniotic fluid during the second half of gestation was obtained. The influence of addition of blood, vernix, and meconium to amniotic fluid as well as that of changes in the pH and dilution were examined. The results were unaffected by either blood, vernix, or pH changes. The slight scatter of the y-min values makes this parameter particularly suitable for determining fetal lung maturity.

Topics: Amniotic Fluid; Blood; Female; Hemolysis; Humans; Hydrogen-Ion Concentration; Meconium; Phosphatidylcholines; Pregnancy; Pregnancy Trimester, Second; Pregnancy Trimester, Third; Sodium Chloride; Surface Properties; Surface Tension; Vernix Caseosa