Hyaline Membrane Disease - HMD
- Exclusively in Preterm (Never in IUGR baby - as they are in stress so release steroids)
- > 30% Neonatal Mortality
- Preterm with respiratory distress.
Normally : Type 2 Pneumocytes produce Pulmonary Surfactant in Alveoli - reduces the surface tension and prevents it from collapsing during expiration.
Surfactant Components :
- Phosphatidyl Choline
- Phosphatidyl Glycerol
- Phosphatidyl ethanolamine
- Phosphatidyl inositol
- Protein A,B,C,D
Term Baby with HMD - if Infant of diabetic mother.
Prenatal Diagnosis : L/S ratio in Amniotic fluid. ( Lecithin / Sphingomyelin )
Normally - L/S >2
but in an Infant of Diabetic Mother , Good L/S is > 3.5
Management Prenatal - IM Betamethasone to mother.
Not Dexa - Because it increases risk of PVL (Periventricular Leuckomalacia)
Benefit occurs only after 24hrs to 7days
PostNatal Diagnosis :
1. Shake Test -
Amniotic fluid or gastric aspirate + Alcohol (equal amount) , shaken for 20 sec.
Then kept in stand for 20 min
- Term : Layer of bubbles at top of test tube.
- Preterm : Bubbles Absent
2. X-Ray - Ground Glass Appearance / White out lungs.
Baby <28wks - 60 - 80% have HMD
1. CPAP - Nasal/PEEP - to keep alveoli distended.
2. Definitive treatment - Surfactant - Prophylactic to preterm , Therapeutic /Rescue
- Route : IntraTracheal
- Most commonly used - Survanta (Bovine)
- Others - Curosurf (Porcine) , Infasurf ( Calf )