II. Indications: Assessment of Fetal Lung Maturity

  1. Gestational age of 34 weeks or more
  2. Assess risk of Hyaline Membrane Disease

III. Signs of adequate surfactant (requires Amniocentesis)

  1. Lecithin to Sphingomyelin ratio (L/S ratio) > 2:1
    1. Positive Predictive Value: 98% (if no comorbidity)
    2. Not accurate in Diabetes, fetal asphyxia, Rh Disease
  2. Phosphatidylglycerol (PG) present >3%
    1. More reliable than L:S ratio if maternal comorbidity
  3. Phosphatidylinositol (PI) present
  4. Desaturated Lecithin (DSL)
    1. Non-Diabetic Patient >1500
    2. Gestational Diabetes Mellitus >2000
    3. Most sensitive of all lung maturity tests
  5. Total Surfactant Activity tests
    1. Fetal Lung Maturity Test (TDX-FLM, Abbott Labs) >70%
    2. Foam Stability Index (Beckman Inst.) >47

IV. Bedside Tests

  1. Tap Test
    1. Mix amniotic fluid with indicators
      1. Start with 1 ml amniotic fluid
      2. Add one drop of 6N Hydrochloric acid
      3. Add 1.5 ml Diethyl ether
    2. Tap tube several times
      1. Forms several hundred bubbles in ether layer
    3. Interpretation
      1. Mature if <6 bubbles in ether layer at 10 minutes
        1. Surfactant expedites bubbles breaking down
  2. Turbidity Test
    1. Hold amniotic fluid tube over newsprint
    2. Mature if fluid prevents reading newsprint
      1. Amniotic fluid turbidity increases with surfactant
      2. Positive Predictive Value: 97%

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Ontology: Phosphatidylinositols (C0031621)

Definition (NCI) A phosphatidic acid combined with inositol found in biomembranes and a precursor to certain cellular signals. Sometimes referred to as inositide. It is a very important minor phospholipid in eukaryotes, involved in signal transduction processes. Contains myo inositol linked through the 1 hydroxyl group to phosphatidic acid. The 4 phosphate (PIP) and 4, 5 bisphosphate derivatives PIP2) are formed and broken down in membranes by the action of specific kinases and phosphatases (futile cycles). Signal sensitive phospholipase C enzymes remove the inositol moiety, in particular from 1,4,5 trisphosphate (PIP2) as inositol 1,4,5 triphosphate (Ins P3: IP3). Both the diacyl glycerol and products act as second messengers.(On-line Medical Dictionary)
Definition (MSH) Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to the hexahydroxy alcohol, myo-inositol. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid, myo-inositol, and 2 moles of fatty acids.
Definition (CSP) derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to the hexahydroxy alcohol, myoinositol.
Concepts Biologically Active Substance (T123) , Lipid (T119)
MSH D010716
SnomedCT 55521004
LNC LP15799-7, MTHU013138
English Inositide Phospholipids, Inositol Phosphoglycerides, Inositol Phospholipids, Phosphoglycerides, Inositol, Phosphoinositides, Phospholipids, Inositide, Phospholipids, Inositol, Phosphatidyl Inositol, Phosphatidylinositol, PtdIns, Inositol, Phosphatidyl, phosphoinositide, PTDIN, inositol phospholipid, Phosphatidylinositols, Phosphatidylinositols [Chemical/Ingredient], phosphatidylinositol, phosphatidyl inositol, PI, Phosphatidyl inositol, Phosphatidyl inositol (substance)
Swedish Fosfatidylinositoler
Czech fosfatidylinositoly, fosfoinositidy
Finnish Fosfatidyyli-inositolit
Italian Inositolo fosfolipidi, Fosfatidil inositolo, Inositolfosfogliceridi, PtdIns, Fosfatidilinositolo, Inositolfosfolipidi, Fosfoinositidi, Fosfatidilinositoli
French PPI (Phosphoinositides), Phosphatidyl inositol, Phosphoinositides, Phosphatidyl inositols, Monophospho inositide
Polish Fosfoinozytydy, Fosfatydyloinozytole
Japanese イノシトールリン脂質, イノシトールホスホグリセリド, ホスファチジルイノシトール, ホスホイノシチド, モノホスホイノシチド, イノシトールホスホリピド, イノシトール燐脂質, ホスファチジルイノシチド
Portuguese Fosfoglicérides de Inositol, Fosfatidilinositóis, Fosfoglicerídeos de Inositol, Fosfoinositídeos, Ptdinas
Spanish fosfatidilinositol (sustancia), fosfatidilinositol, Fosfatidilinositoles, Fosfogliceridos de Inositol, Fosfoinositidos, PtdIns
German Inositol-Phosphoglyceride, Phosphatidyl-Inositole, Phosphoinositide, Ptdlns