6. Surfactant Replacement Therapy in Neonates Flashcards
What is the action of surfactant, specifically related to surface tension?
reduces surface tension
Decreased surfactant can lead to what syndrome?
RDS
How does Leplace’s Law apply to the alveoli?
P = 2(ST)/R
the smaller the alveoli, the more pressure required to inflate it
Surface tension causes alveoli to _____ and requires _____ pressure to ventilate.
collapse, high
Surfactant coats the inside of the ____, ____ surface tension, and prevent alveoli from ______.
alveoli, lowers, collapse
List some function of surfactant. (Hint: there are 7)
prevents collapse of alveoli during expiration, decreased WOB and O2, optimizes surface area for gas exchange (improves V/Q mismatch), improves lung compliance, protects lung epithelium and facilitates clearance of foreign materials, prevents capillary leakage of fluid into alveoli, defends against infection
List some benefits of surfactant therapy. (Hint: there are 6)
improves oxygenation/ventilation, reduces rates of pneumo/PIE, faster weaning/quicker extubation, reduced rates of BPD, less severe BPD, reduced mortality
What type of compound on surfactant? Where is it formed?
lipid/protein compound
formed in type II cells
T or F: surfactant phospholipids form a bilayer of the alveolar air-liquid interface.
F: monolayer
What is the composition of surfactant?
lipids = 90% (phospholipids/DPPC - 90%, neutral lipids - 10%, cholesterol - minimal) proteins = 10% (serum proteins - 80%, surfactant specific proteins - 20%)
What are the 4 serum specific proteins? What is their % composition of surfactant?
SP-A, SP-B, SP-D, SP-D, 20%
List some characteristics of SP-A and SP-D.
collagen like, most abundant, hydrophillic, immune function, not found in commercial surfactant extracts
List some characteristics of SP-B and SP-C.
important in reabsorption, facilitate DPPC spread/stabilization, hydrophobic, found in commercial surfactant preparations
A deficiency in which serum specific protein leads to death in the infancy?
SP-B
Survanta (Beractant): source? composition? dose?
bovine lung mince
DPPC, neutral lipids SP-B/SP-C
4 ml/kg (100mg/kg)
re-treatment may be given as early as 2hr after initial dose
Bles (Neosurf): source? composition? dose?
bovine lung lavage
DPPC, neutral lipids SP-B /SP-C
5ml/kg (135mg/kg)
repeat up to 3 times within the first 5 postnatal days if oxygenation difficulties persists
Curosurf (Poractant alfa): source? composition? dose?
porcine
DPPC, neutral lipids SP-B/SP-C
2.5ml/kg (200mg/kg)
2 repeat doses 1.25ml/kg 12 hrs apart, max 5ml/kg total
Describe the surfactant treatment for RDS in neonates < 24-26 weeks.
intubate and administer surfactant at birth, patient will remain intubated
Describe the surfactant treatment for RDS in neonates > 24-26 weeks.
administer surfactant if pt requires intubation at birth
NIV with FiO2 > 30-40% then intubate and administer surfactant
extubate ASAP
When should surfactant doses be repeated in relation to FiO2?
FiO2 increase > 30-40%
What are some examples of non RDS use of surfactant?
meconium aspiration syndrome, congenital pneumonia, pulmonary hemorrhage, bronchopulmonary dysplasia, congenital diaphragmatic hernia, bronchiolitis, ARDS
What are some hazards/complications related to surfactant therapy?
desat, brady, tachy, reflux into ETT, apnea, plugging of ETT, pulmonary hemorrhage, may open DA
What are some special considerations for surfactant administration?
emergency airway equipment ready, optimize lung volume before surfactant admin (PEEP), administration through in-line catheter, lung volumes/ventilation should be maintained during admin to help disperse surfactant homogeneously
What type infusion should be used to deliver surfactant? Dose? Position?
bolus (better distribution/improvement in oxygenation), single dose, supine position
