A comparison of the lecithin/sphingomyelin ratio and shake test for estimating fetal pulmonary maturity

Application of axisymmetric drop shape analysis and brewster angle microscopy for assessment of clinical samples from prematurely born infants with NRDS

“…Nowadays, the most popular and employed biochemical methods for surfactant maturity testing include determination of: protein/phospholipids [9], and lecithin/sphingomyelin ratios in clinical samples [10][11][12][13][14]; the number of the lamellar bodies in amniotic fluid [14][15][16][17]; the presence of specific surfactant proteins [18], etc. In addition, the most commonly used biophysical methods for surfactant maturity assessment are: black foam film method [19,20]; decreasing the surface tension of clinical samples extractions [21,22]; foam stability test [15,[23][24][25]; microbubbles stability test [26][27][28]; click-method for bubbles formation [29][30][31], etc. The summary of the results from all these analyses shows that none of the techniques can find widespread application into the clinical practice; these methods are slow, require large quantity of the clinical sample, high qualified specialists, etc.…”

A comparative study between the values of lecithin, sphingomyelin, lysolecithin, the L/S Index, and the CLEMENTS test in amniotic fluid

“…They observed that an L/S index below 1.5 is accompanied by respiratory distress syndrome (RDS) in nearly 90% of the cases, while with an index above 2 this syndrome is seldom present. These results were later widely confirmed by other authors using the same method, but whose results differed from those of GLUCK; i.e., DONALD (63%) [10], GOLDSTEIN (36%) [16], SPELLACY (33%) [26] and HOBBINS (25%) [17]. However, the techniques employed to obtain these results require the availability of a very well equipped laboratory, which means that their use is limited to large centres.…”

Lecithin/sphingomyelin Ratio versus Rapid Surfactant Test in Normal and Diabetic Pregnancies

“…Comparative studies between L/S ratio and RST were done to determine the more reliable test: Some authors (2, 12) claim that RST gives better prediction of RDS than does L/S ratio measurement. Others (10,14,22) found good correlation between RST and L/S ratio but suggested use of the RST as a screening test; a positive result being reliable but a negative RST requiring L/S ratio determination. According to Whitfield et al (25) the normal sustained terminal rise in the amniotic fluid L/S ratio failed to occur in almost one-third of diabetic pregnancies.…”

“…In the studies mentioned above (2,10,17), no distinction was made between normal and pathological pregnancies.…”