Approach to Respiratory Distress-HMD in Newborn

1. Approach to Respiratory Distress-HMD in
Newborn

3. • A 32 weeks preterm baby born to a GDM mother by LSCS, developed
distress, grunting, cyanosis soon after birth. His SPO2 was 90%,
hyperoxia test was positive. Downe’s score was 7, silverman-anderson
score 8. Urgent CXR was done which showed :

4. RDS
4

5. Now what next ???
• Baby shifted to NICU and put on warmer. RBS was normal, other
blood samples taken. IV fluids were started, ABG was done which
showed acidosis.
• Baby was put on nasal CPAP, meanwhile survanta was arranged.
• Baby then put on venti, surfactant given at 4 hours of life.
• Now clinically better.

6. SIGNS AND SYMPTOMS
• Tachypnea (RR > 60/min)
• Nasal flaring
• Retraction
• Grunting
• +/- Cyanosis
• +/- Desaturation
• Decreased air entry

7. General
Considerations

8. RD IN NB- Causes
• Pulmonary
- Parenchymal
- Extraparenchymal
• Non Pulmonary
- Heart
- Metabolic
- Brain
- Blood
- Abdominal

9. RD in Newborn – Causes
Pulmonary
Parenchymal Extraparenchymal
* RDS (HMD) * Upper airway obstruction
* TTN (RDS II) (Cloanal atresia, stenosis)
* Aspiration (Blood * Pneumothorax
meconium) * Pleural effusion
* PPHN * Cong. Diaph. hernia
* Pneumonia * Diaphragmatic paralysis
* Pulm. hemorrhage
* Pulm. hypoplasia

10. RD in Newborn – Causes
Extrapulmonary
Heart Metabolic Brain Blood
Abdominal
- CCF - Met. Acidosis - Haemorrhage - Hypovolemia - NEC
- PDA - Hypoglycemia - Edema - Hyperviscosity - Pneumo
- CCHD - Hypothermia - Drugs - Acute blood
peritonium
- Vascular - Sepsis - Pain loss - Large
mass

11. Surgical causes of respiratory distress
• Tracheo-esophageal fistula
• Diaphragmatic hernia
• Lobar emphysema
• Pierre -Robin syndrome
• Choanal atresia

12. Suspect surgical cause
• Obvious malformation
• Scaphoid abdomen
• Frothing
• History of aspiration

13. A progressively increasing O2 requirement to
maintain saturation is also a sensitive indicator
of the severity and progress of distress
>95% Term baby, pulmonary hypertension (PPHN)
88-94% 28-34 weeks preterm
85-92% Below 28 weeks gestational age
Guidelines for monitoring oxygen saturation levels
by pulse oximetry
MJAFI, Vol. 63, No. 3, 2007
General
Considerations

14. Hyperoxia test
test Method result diagnosis
Hyperoxia 100 % fio2 5-10
min
Pao2 increases to
> 100 torr
Pao2 increases by
< 20 torr
Parenchymal
lung disease
PPHN / CCHD
Hyperoxia-
hypervetilation
MV 100 % fio2 &
VR 100-150 /
min
Pao2 increases to
> 100 torr
w HV
Pao2 increases
at critical Pco2
No increase in
Pao2 with HV
Parenchymal
lung disease
PPHN
CCHD

15. Downe’s score

16. Silverman-Andersen Retraction Scoring
Interpretation
Score 0-3 = Mild respiratory distress
Score 4-6 = Moderate respiratory distress
Score > 6 = Impending respiratory failure
Score 10 = Severe Respiratory distress
General
Considerations

17. Investigation
Complete Blood Count with a Peripheral blood smear
Sepsis screen including C-reactive protein and μ ESR
Arterial blood gas (ABG) analysis
Blood glucose, Serum calcium
Cultures: Blood , Surface swab (where indicated),
maternal vaginal swab
Chest radiograph with an oro-gastric tube in situ
General
Considerations

18. Mathai ss et al ,MJAFI 2007; 63 : 269-272

19. RR
(bpm
Aspiration cong. Pneumonia, sev. HMD CDH
cardiac malformation
Approx. 6 Hours of age
Normal
60
Course of Neonatal Tachypnoea : Etiologic possibilities
Source : Baurn DJ, Birth Risks, Nastle Nutrition Workshop, 1993
TTNB
HMD

20. Evaluation of RD in NB – Clinical History
Antenatal History Most likely association
* Prematurity, IDMs * HMD
* PROM, maternal fever, * Pneumonia
Unclean vaginal exams,
UTI, diarrhoea
* Asphyxia/MSAF * Aspiration
* Caesarean delivery * TTN
* Polyhydramnios * Pulm. Hypoplasia
* Oligohydramnios * TE fistula, CDH
* H/o receiving steroids * RDS less
* Traumatic/breech delivery * ICH / Phrenic nerve paralysis

21. HMD/RDS

22. Respiratory Distress Syndrome (RDS)
• Also known as Hyaline Membrane Disease (HMD)
• Commonest cause of preterm neonatal mortality
• RDS occurs primarily in premature infants; its incidence
is inversely related to gestational age and birth weight
Nelson Textbook of Pediatrics, 18th
Ed.
Gestational age Percentages
Less than 28 wks 60-80%
32-36 wks 15-30%
37-39 wk 5%
Term Rare
Resp.
Dis.
Syn.

23. ETIOLOGY AND PATHOPHYSIOLOGY.
• Surfactant deficiency is the 1O
cause of RDS.
• Low levels of surfactant cause high surface tension
• High surface tension makes it hard to expand the alveoli.
• Tendency of affected lungs to become atelectatic at end-
expiration when alveolar pressures are too low to
maintain alveoli in expansion
• Leads to failure to attain an adequate lung inflation and
therefore reduced gaseous exchange

24. • With advancing gestational age, increasing amounts
of phospholipids are synthesized and stored in type II
alveolar cells .
• Wk 20: start of surfactant production and storage.
Does not reach lung surface until later
• Wk 28-32: maximal production of surfactant and
appears in amniotic fluid
• Wk 34-35; mature levels of surfactant in lungs
• Quality : The amounts produced or released may be
insufficient to meet postnatal demands because of
immaturity.
• Surfactant inactivating states eg maternal DM may
lead to surfactant of lower quality/ immature

25. • Rare genetic disorders may cause fatal respiratory
distress syndrome eg.
• Abnormalities in surfactant protein B and C genes
• gene responsible for transporting surfactant across
membranes (ABC transporter 3 [ABCA3]) are associated
with severe and often lethal familial respiratory disease

26. 26
Clinical manifestation
• Tachypnea
• Nasal flaring
• Intercostal, sternal recession
• Grunting; closure of glottis during expiration
• Cyanosis