Neonatal Respiratory Distress Syndrome Flashcards
Which neonates are more likely to get Respiratory Distress Syndrome (RDS)
Less than 36 weeks gestational age
What is the pathophysiology of RDS
Pulmonary surfactant deficiency: inadequate surfactant will require higher inspiratory pressures to re-expand alveoli and achieve gas exchange
What are the roles of pulmonary surfactant
Decreases surface tension forces at air:fluid interface at alveoli, prevents alveolar collapse (atelactasis), facilitates clearance of pulmonary fluid
Why are neonates less than 36 weeks more likely to acquire RDS
Endogenous cortisol stimulates synthesis and secretion of pulmonary surfactant at 30-32 weeks of gestation and sufficient amounts are not reached until 36 weeks of gestation
What is the increased risk risk factors
Prematurity, gestational diabetes, C-section without labor, male gender
What are the decreased risk risk factors
Maternal hypertension, maternal narcotic addition, cardiovascular disease
What are the sequence of events caused by diminished surfactant
Progressive atelectasis -> hypoventilation -> increased partial carbon dioxide/decreased oxygen/low pH -> hypotension -> pulmonary vasoconstriction -> alveolar hypoperfusion
What is the clinical presentation of a patient with RDS, when would this be seen
Tachypnea, hypoxemia, hypercapnia, within the first six hours of life
Who is RDS diagnosed
X-ray findings (diffuse reticulogranular pattern)
What is the medication used to treat RDS, how does it alleviate the problem
Antenatal glucocorticoids: increases production fibroblast neumocyte factor, stimulates biosynthesis of surfactant in type II pneumocytes
What are the atenatal glucoroticoids given
Betamethasone 12 mg IM every 24 hours for 2 doses OR dexamethasone 6mg IM every 12 hours for 4 doses
What are the categories of drugs that are given to prevent premature delivery and allow for the steroids to start working
Beta-adnergic agonists, magnesium sulfate, prostaglandin inhibitors, calcium channel blockers
What is the beta-adnergic agonist used to prevent premature delivery
Terbutaline (No longer used due to adverse effects)
What is the MOA of magnesium for preventing premature delivery, what concentration does the magnesium sulfate need to be at
Inhibiting voltage- independent calcium channels at myometrial cell surface, 4-8 mg/dL (loading dose IV then continuous infusion)
What are the adverse effects of magnesium sulfate in the mother, in the neonate
Mother: N/V, flushing, headache, blurred vision, pulmonary edema, shortness of breath, chest pains
Neonate: respiratory depression, slow GI function (also has neonatal neuroprotection)
What is used in conjunction with magnesium to prevent preterm delivery, when can it ONLY BE TAKEN
Indomethacin, gestation age LESS THAN 30 weeks
What is the only CCB that can be used to prevent premature delivery. adeverse effects
Nifedipine, headache, tachycardia, palpatations
If a patient has RDS what can be done for supportive care to aid in breathing, what is this to prevent
Supplemental O2, CPAP, mechanical ventillation/ respiratory and metabolic acidosis
What is a common problem for patients with RDS, how can this be prevented
Pulmonary Edema, 120-130 ml/kg/day
When would diuretic be used in a patient with RDS, which diuretic would be used, what is the largest con with doing this
Reserved for neonates with pulmonary edema OR cannot be removed from the ventilator, furosemide 1-2 mg/kg/day in 1-2 divided doses, increases the ductus arterious opening
What is adequate nutrion for patients with RDS, empiric antibiotic therapy to prevent what
100-110 kcal/kg/day/ ampicillin and gentamicin to prevent sepsis
What is the major surface-active component of human surfactant, most important proteins for human surfactant for patients with RDS and why
DPPC or lecithin/ SP-B and SP-C: enhances spreadability and surface adsorption leading to DECREASED SURFACE TENSION
What are the three FDA approved surfactant products for treatment and prevention of RDS
Beractant: 100 mg/kg PL , calfactant: 105 mg/kg PL, poractant: 200 mg/kg PL
What are the natural surfactants, ones used for prevention and treatment, treatment only
Calfactant and Poractant, calfactant and Beractant/ Poractant
T/F: Patients must be intubated in order to recieve natural surfactants
True
What are the therapeutic effects of natural surfactants
Decreased supplemental oxygen and mechanical ventilation, decreased incidence of pneumothorax and PIE, increase survival by 40% regardless of birth weight or gestation age, reduce mortality of RDS by 50%
What is the benefits of using the natural surfactants (calfactant and poractant), what is a significant improvement of poractant
Longer duration of effect (dosed every 12 hours), faster weaning from the ventilator, less supplemental oxygen required/ lower incidence or mortality and re-dosing
When is it best to use surfactants in patients with RDS
Early therapy: given within two hours of life, Rescue therapy: once the patient is diagnosed
How is it known a patient needs a 2nd dose of surfactant
Intubated infant requiring FIO2 greater than or equal to 30% to maintain arterial PaO2 greater than or equal to 50 mmHg or oxygen saturation greater than 90%
What are the monitoring parameters of giving surfactants
heart rate, oxygen saturation, arterial blood gas
What are the adverse effects of giving surfactants
oxygen desaturation, transient bradycardia, mucous plugging, increased risk of pulmonary hemmorrhage and apnea
