Case Presentation on Respiratory Distress Syndrome and Surfactant Therapy in RDS

1. 
Respiratory Distress Syndrome
Cristal Ann Laquindanum, 2nd yr Pediatrics Resident, The Medical City

2. Identifying Data
 Baby SDC
 Preterm baby girl
 Delivered via STAT CS for non-reassuring
fetal status (impending eclampsia)
 To a 30 year old G1P1 (0101) at 35 4/7
weeks age of gestation

3. Maternal History
 Yeast infection at 4 months age of
gestation, treated with fluconazole
(Diflucan)
 Pre-eclampsia at 32 weeks
 usual BP monitoring (118-159/67-83)
 On Methylodopa 250 mg BID
 No ante-natal corticosteroids given

4. Past Medical History
 Congenital heart disease
 Moderate tricuspid regurgitation and
pulmonary regurgitation (no maintenance
medications)
 Had urinary tract infection (treated with
antibiotics) prior to pregnancy
 No allergies, no asthma, no past
hospitalizations

5. Family History
 Diabetes
 Hypertension

6. Personal Social History
 College graduate
 Self-employed
 Denies smoking and drinking
 Drinks coffee once a day

7. Obstetric History
 G1 – present pregnancy

8. Physical Examination
 Anthropometrics:
 Birth weight : 3,060 g
 Birth length : 48 cm
 Head circumference : 35 cm
 Abdominal circumference : 32 cm
 Chest circumference : 29 cm
 Apgar : 9,9
 Maturity testing : 36 weeks appropriate for
gestational age

9. Physical Examination
 General: Good cry and activity
 Skin: acrocyanotic, with Mongolian spot on sacrum, no tufts of
hair at the back
 HEENT: patent nares, open and flat fontanels, no caput or
molding, no cleft or lip palate, no neck masses
 Cardiac: good cardiac tone, no murmur, HR 130s
 Respiratory: no alar flaring, no retractions, good air entry
 Gastrointestinal: soft non-distended abdomen, normal umbilical
vessels (2 arteries and 1 vein), patent anus
 Genitalia: grossly female genitalia
 Extremities: no limb deformities, full pulses

10. 
Admitting Impression
Live, preterm, baby girl
Delivered via stat caesarian section for non-reassuring fetal status
BW 3,060 g, BL 48 cm, HC 35 cm, AC 32 cm, CC 29 cm
To a 30 year old G1P1 (0101) at 35 4/7 weeks AOG
Apgar 9,9 Maturity testing 36 wks AGA

11. Course in the Wards
1st HOUR
S> grunting with mild pallor, no
cyanosis
O> T 36.5 HR 144 RR 78 BP 64/32
O2 sat 78% at room air, 93% with
O2 1lpm via nasal cannula
With good air entry, no alar
flaring, with subcostal
retractions, full pulses
A> Transient Tachypnea of the
Newborn vs Respiratory Distress
Syndrome
P> Transfer to NICU Level 3
Provide O2 support
Hgt at 2nd hour of life
Septic work-up
CBC, BCS, CRP
Started antibiotics
Ampicillin 104.6 mkday
Cefotaxime 104.6 mkday
Start IV fluids, D10W at TFR 80

12. Course in the Wards
1st HOUR
grunting
tachypnea
retractions
desaturations
S> grunting, no cyanosis, no
pallor
O> T 37.2 HR 145 RR 80s, O2
sat 87-91% at 1lpm via nasal
cannula
Alar flaring, suprasternal and
subcostal retractions, fair air
entry on the left, harsh
breath sounds,
Hgt 83 mg/dl
3rd HOUR
A> TTNB vs RDS
P> Hook to mechanical
ventilator (CPAP mode)
FiO2 80
PEEP 5
Insert umbilical catheter
for venous access
Get venous blood gas

13. Course in the Wards
1st HOUR
grunting
tachypnea
retractions
desaturations
Grunting
Tachypnea
Retractions
Air entry R>L
Desaturations
3rd HOUR
S> grunting, no cyanosis
clear secretions suctioned
O> persistently tachypneic
RR 70s-80s, Harsh breath
sounds, air entry better on
the right, subcostal
retractions
VBG: submaximally
compensated respiratory
acidosis, adequate
oxygenation
4th HOUR
pH 7.304
paCO2 55.9
PaO2 44.9
HCO3 28
BE 1.4
O2 sat 74.9%
CPAP mode
FiO2 80
PEEP 5

14. Course in the Wards
1st HOUR
grunting
tachypnea
retractions
desaturations
Grunting
Tachypnea
Retractions
Air entry R>L
Desaturations
3rd HOUR
S> grunting, no
cyanosis
clear secretions
suctioned
O> persistently
tachypneic RR 70s-
80s, Harsh breath
sounds, air entry
better on the right,
subcostal retractions
VBG: respiratory
acidosis
4th HOUR
A> TTNB vs RDS
P> Adjust mech vent
settings (SIMV mode)
FiO2 80 IT 0.45
PIP 19 FR 10
PEEP 5 RR 60
Repeat VBGs after 3
hours (7th hr of life)
For chest xray
(AP-lateral)

15. Course in the Wards
4th HOUR
Grunting
Tachypneic
Harsh breath sounds, air
entry better on the right
Subcostal retractions
Respiratory acidosis
O2 support via RAM
cannula, SIMV mode
Near complete opacification of the left lung with peripherally extending air
bronchograms. Left cardiac border, left hemidiaphragm are obscured. Reticular
densities are seen in the right inner lung zone
Chest xray:
Respiratory Distress
Syndrome
vs
Neonatal Pneumonia

16. Course in the Wards
10th-13th HOUR
S> Still with occasional
grunting, no cyanosis
O> RR 80s, alar flaring,
subcostal retraction, O2
sat 94-95% at SIMV
mode
VBG: submaximally
compensated
respiratory acidosis with
inadequate
oxygenation
pH 7.270
paCO2 61.1
PaO2 37.5
HCO3 28.3
BE 1.2
O2 sat 61.8%
SIMV mode
FiO2 80 IT 0.45
PIP 19 FR 10
PEEP 5 RR 60
A> RDS vs Pneumonia
P> Intubate with ET F3.5
For chest x-ray (AP-lateral)
Adjust mech vent settings
(SIMV mode)
FiO2 60 IT 0.45
PIP 23* FR 10
PEEP 5 RR 60
Give surfactant (Survanta)
12 ml per ET (3.9 ml/kg)
Repeat VBGs the next day
CBC
Hgb 156
Hct 47
WBC 20.6
Neutro 60
Lympho 10
Mono 6
Eosino 4
Plt 172
CRP
0.04 normal

17. Course in the Wards
10th-13th HOUR
Occasional grunting
Tachypneic
Alar flaring
Subcostal retractions
Respiratory acidosis
Intubated
Given surfactant
(3.9ml/kg)
Repeat Chest xray
Repeat VBGs
Completely opacified left lung is unchanged, left cardiac border and
hemidiaphragm are indistinct. ET 1.2 cm above the carina. OGT tip within the
gastric cavity. UVC tip at the level of T10 vertebra.
Chest xray:
Respiratory Distress
Syndrome
vs
Neonatal Pneumonia

18. Course in the Wards
20th HOUR
S> no grunting, still NPO,
on D10W TFR 80, no
vomiting
O> RR 60-69, no
desaturation, good air on
the right, fair air entry on
the left, harsh breath
sounds, with subcostal
retractions
VBG: uncompensated
respiratory acidosis with
inadequate oxygenation
pH 7.298
paCO2 51.0
PaO2 41
HCO3 25.0
BE -1
O2 sat 70%
SIMV mode
FiO2 80 IT 0.45
PIP 19 FR 10
PEEP 5 RR 60
A> Increase TFR to 90
Adjust mech vent settings
SIMV mode
FiO2 50 IT 0.45
PIP 20 FR 10
PEEP 5 RR 60

19. Course in the Wards
20th HOUR
No grunting, RR 60-69, no
desaturation, good air on
the right, fair air entry on
the left, harsh breath
sounds, with subcostal
retractions
VBG: respiratory acidosis
FiO2 50 IT 0.45
PIP 20 FR 10
PEEP 5 RR 60
Partial areration of the left upper lung field. Peripherally extending air
bronchograms on the left are still seen. Interval clearing of minimal reticular
densities on the right
Chest xray:
Regressing surfactant
deficiency disorder

20. Course in the Wards
3rd DAY
S> started feeding per OGT,
no vomiting, no desaturations,
no cyanosis, no pallor
O> RR 69-76 HR 129-176
Light jaundice to neck, good
air entry but better on the
right, harsh breath sounds with
rales, shallow subcostal
retractions, clear secretions
from ET
On Ampicillin day 3 ½ and
Cefotaxime day 3 ½
VBG: Submaximally
compensated respiratory
acidosis with inadequate
oxygenation
pH 7.342
paCO2 54
PaO2 37.9
HCO3 29.5
BE 3.6
O2 sat 67.4
SIMV mode
FiO2 35 IT 0.45
PIP 16 FR 10
PEEP 5 RR 45
Chest xray:
Regressing surfactant deficiency disorder,
interval development of
consolidation/atelectasis on the right

21. Course in the Wards
3rd DAY
S> started feeding per OGT,
no vomiting, no desaturations,
no cyanosis, no pallor
O> RR 69-76 HR 129-176
Light jaundice to neck, good
air entry but better on the
right, harsh breath sounds with
rales, shallow subcostal
retractions, clear secretions
from ET
On Ampicillin day 3 ½ and
Cefotaxime day 3 ½
VBG: Submaximally
compensated respiratory
acidosis with inadequate
oxygenation
A> RDS, resolving
P> Interval increase in
feedings
Adjust mech vent settings
SIMV mode
FiO2 31* IT 0.45
PIP 16 FR 10
PEEP 5 RR 45
Decrease FiO2 by 10% if
settings are tolerated until
FiO2 reaches 21%
Suction secretions regularly

22. Course in the Wards
3rd DAY
Tolerated feedings
Occasional tachypnea
Light jaundice to neck
good air entry but better on
the right, harsh breath sounds
with rales, shallow subcostal
retractions, clear secretions
from ET
On Ampicillin day 3 ½
Cefotaxime day 3 ½
Respiratory acidosis
Chest xray: regressing RDS
with atelectasis/consolidation
5th DAY
S> tolerates 19 ml of
feedings per OGT, no
vomiting
Clear secretions via ET
Weight gain noted
O> HR 124 RR 32 O2 sat
98%
Good air entry, bibasal
rales. No alar flaring, no
retractions noted
Current MV setting
SIMV mode
FiO2 23 IT 0.45
PIP 10 FR 10
PEEP 2 RR 20
A> RDS, resolving
P> For extubation
O2 support via RAM
cannula CPAP mode
then nasal cannila if
tolerated
Racemic
epinephrine for 24 hrs

23. Update
• Day 12 of life
• Corrected age 37 3/7 weeks
• Extubated
• On full oral feeds, fed as tolerated
• Occasional tachypnea, no desaturations, with shallow
to deep retractions
• Single phototherapy started
• Ampicillin and Cefotaxime completed for 10 days

24. 
Discussion

25. Definition
 formerly referred to as hyaline membrane disease
 Preterm birth is the most common etiologic factor
 Primary cause is inadequate pulmonary surfactant
 diagnosis can be established pathologically or by
biochemical documentation of surfactant
deficiency
 combination of clinical and radiographic features

26. Incidence
 slight male predominance
 Inversely proportional to gestational age
 95% to 98% of infants born at 22 to 24 weeks
 decreasing to approximately 25% in infants with
birth weights between 1251 and 1500 g
 infants of 34 weeks’ gestation and above
 Risk decreases from 5% at 34 weeks to less than
1% at 37 weeks

27. Pathophysiology
 Lung structural development (4
stages)
 Embryonic period
 First appearance of fetal lung
and initial branching
 Pseudoglandular stage
 airway branching
 Canalicular stage
 Saccular and alveolar stage

28. Pathophysiology
 Canalicular stage
 transition from previable to a
potential viable lung
 respiratory bronchioles and
alveolar ducts of the gas
exchange region of the lung are
formed
 After 20 weeks gestation,
cuboidal epithelial cells begin to
differentiate into alveolar type II
cells with formation of
cytoplasmic lamellar bodies
 The glycogen in type II cells
provides substrate for surfactant
synthesis as the lamellar body
content increases.
 Saccular and alveolar stage
 About 24 weeks gestation, there is
potential for viability because gas
exchange is possible due to the
presence of large and primitive
forms of the future alveoli.
 Alveolarization occurs at this stage
 The most rapid rate of
accumulation of alveoli occurs
between 32 weeks’ gestational
age and the first months after term
delivery
 Alveolar growth continues for at
least two years after birth at term.

31. Lung Compliance

32. Risk Factors
 Prematurity
 Maternal diabetes
 C-section delivery
 Asphyxia

33. Clinical Manifestations
 Tachypnea
 Nasal flaring
 Grunting
 Intercostal, subxiphoid, and subcostal
retractions
 Cyanosis

34. Differential Diagnosis
 Early-onset sepsis
 may be indistinguishable from RDS
 Pneumonia,
 the chest radiograph may be identical to that for RDS
 Cyanotic heart disease
 total anomalous pulmonary venous return can also mimic RDS both
clinically and radiographically
 Echocardiography with color-flow imaging  infants who show no
response to surfactant replacement
 Transient tachypnea
 shorter and milder clinical course
 low or no need for oxygen supplementation

35. Diagnosis
 Onset of progressive respiratory failure shortly
after birth
 Characteristic chest radiograph
 ABG
 Hypoxia
 Hypercarbia

36. CXR
low lung volume and the classic
diffuse reticulogranular ground-
glass appearance with air
bronchograms

37. CXR

38. Prevention
 Avoidance of unnecessary or poorly timed early
cesarean section (<39 wk) or induction of labor
 appropriate management of high-risk pregnancy
and labor (including administration of antenatal
corticosteroids)
 Antenatal and intrapartum fetal monitoring may
decrease the risk of fetal asphyxia

39. Prevention
 Antenatal glucocorticoids
 Enhances maturational changes in lung architecture
and inducing enzymes
 Stimulate phospholipid synthesis and release of
surfactant
 All pregnant mothers at risk for preterm delivery at or
below 34 weeks gestation should receive ACS
 Steroid administration is recommended for all women
in preterm labor who are likely to deliver a fetus within
1 wk.

40. Prevention
 Antenatal glucocorticoids
 Betamethasone may reduce neonatal death to a greater
extent as compared to dexamethasone (2 doses 24 hours
apart)
 Antenatal steroid administration has been shown to be
beneficial if provided fewer than 24 hours before delivery
 Reduction in RDS has been seen in infants born up to 7 days
after the first dose of antenatal steroids was administered.
 No benefit is seen in infants who receive the first dose of
steroids more than 7 days before birth.

41. Treatment
 Pharmacologic
 Systemic corticosteroids have been used but not
recommended due to short term adverse effects
 Inhaled nitric oxide (iNO) decreases the need for
extracorporeal membrane oxygenation (ECMO) but is not
routinely done
 Supportive Care
 Thermoregulation
 Fluid Management
 Nutrition

42. Treatment
 Surfactant Therapy
 Immediate effects: improved alveolar-arterial oxygen gradients,
reduced ventilatory support, increased pulmonary compliance, and
improved chest radiograph appearance
 Repeated dosing is given every 6-12 hr for a total of 2 to 4 doses
 Weaning strategies vary: transition to nasal CPAP to avoid postextubation
atelectasis and reduce re-intubation.
 Assisted Ventilation Techniques
 arterial blood pH <7.20
 arterial blood Pco2 of 60 mm Hg or higher
 oxygen saturation <90% at oxygen concentrations of 40-70% and CPAP
of 5-10 cm H2O
 persistent apnea

43. 
Surfactant Therapy in RDS
Source: Surfactant Replacement Therapy for Preterm and Term Neonates With Respiratory Distress,
AAP Clinical Report, 2014

44.  Surfactant replacement was established as an effective and
safe therapy for immaturity-related surfactant deficiency by the
early 1990s
 RCTs: reduces mortality, decreases the incidence of pulmonary
air leak (pneumothoraces and pulmonary interstitial
emphysema), and lowers the risk of chronic lung disease or
death at 28 days of age
 Recent randomized clinical trials indicate that the benefits of
prophylactic surfactant are no longer evident in groups of
infants when continuous positive airway pressure (CPAP) is used
routinely

45. PRETERM INFANTS AND SURFACTANT
EFFECTIVENESS IN CLINICAL TRIALS
 infants born between 23 and 34 weeks’ gestation and/or with
birth weight be- tween 500 and 2000 g are included in the trials
 decreased mortality rates most effectively in infants born at less
than 30 weeks’ gestation or with birth weight <1250 g.
 reduced the incidence of pneumothorax, pulmonary interstitial
emphysema, and the combined outcome of death or BPD
 onset of clinical signs of PDA may occur earlier, and the
incidence of pulmonary hemorrhage, especially in infants born
at less than 27 weeks’ gestation, may be increased with
surfactant therapy

46. PROPHYLACTIC VERSUS RESCUE SURFACTANT
 Prophylactic, or preventive, surfactant strategy
 high risk of developing RDS
 primary purpose of preventing worsening RDS rather
than treatment of established RDS
 surfactant administration in the delivery room before
initial resuscitation efforts or the onset of respiratory
distress or, most commonly, after initial resuscitation
but within 10 to 30 minutes after birth.

47. PROPHYLACTIC VERSUS RESCUE SURFACTANT
 Rescue or treatment surfactant strategy
 given only to pre-term infants with established RDS
 most often administered within the first 12 hours after
birth, when specified threshold criteria of severity of
RDS are met

48.  Meta-analysis of studies conducted before routine application of CPAP
 demonstrated a lower mortality rate and a decrease in the risk of air leak
with prophylactic surfactant
 Studies that allowed for routine application of CPAP were included in
the meta-analysis
 the benefits of prophylactic surfactant on mortality and air leak could no
longer be demonstrated
 Prophylactic surfactant
 higher incidence of BPD or death than did infants stabilized on CPAP
 increased risk of chronic lung disease in infants born at <30 weeks’
gestation
PROPHYLACTIC VERSUS RESCUE SURFACTANT

49. EARLY VERSUS DELAYED SELECTIVE
SURFACTANT TREATMENT OF RDS
 Early rescue: surfactant treatment within 1 to 2 hours
of birth
 Late rescue: surfactant treatment 2 or more hours
after birth
 risks of mortality, air leak, chronic lung disease, and
chronic lung disease or death were significantly
decreased with early rescue

50. Surfactants

51. Clinical Implications

52. 
Thank you!
Cristal Ann Laquindanum, 2nd yr Pediatrics Resident, The Medical City