1. RESPIRATORY DISTRESS SYNDROME
By Dr. Gacheri Mutua

2. DEFINITION Also known as Hyaline Membrane Disease
Is a respiratory disorder that affects newborns
More common in premature infants especially born 6wks or more before their due date
Their lungs have insufficient surfactant, necessary to maintain lung compliance

3. Disease is exacerbated by:
Cold stress
Hypoxia
Acidosis
Sepsis
Natural history- clinical signs develop within 6hrs of life with progressive worsening over the first 48 to 72hrs of life

4. Predisposing factors Prematurity
Male gender and are more likely to die from the disease
Caucasian > black
Caesarean section
Low APGAR score
Maternal diabetes
Congenital hypothyroidisim
Familial predisposition
Twins
Postnatal hypothermia
Maternal malnutrition
Intrauterine growth retardation
Hemolytic disease of the newborn

5. DIAGNOSIS Clinical:- Radiological features:- Haematological:-
tachypnoea
grunting respirations
intercostals recession, sternal indrawing
nasal flaring
cyanosis
increased oxygen requirements
deranged cardiovascular parameters: HR, BP
Radiological features:-
Air bonchograms with characteristic ground glass appearance
Haematological:-
anaemia
Thrombocytopenia
Blood gas measurements
Mixed metabolic and respiratory acidemia

6. PREVENTION Prevent premature delivery Antenatal steroid therapy
Drugs to mature surfactant synthetic pathways: aminophylline
Prevent asphyxia
Avoid drugs that cause respiratory depression
The course of the disease is altered by exogenous surfactant therapy and assisted ventilation

7. MANAGEMENT Non-respiratory Temperature control Avoid enteral feeding
IV therapy 5% or 10% dextrose
Closely monitor blood glucose
Antibiotics: penicillin, gentamicin
Assess the baby's circulatory status by monitoring heart rate, peripheral perfusion, and blood pressureAdminister blood or volume expanders, and use appropriate vasopressors to support circulation where necessary.

8. Respiratory
Airway- place infant in lateral or prone posture rather than supine
Repeated suctioning of pharynx is not required and may cause apnoea and hypoxia

9. Oxygen Administer humidified oxygen at flow rates of 6-8l/min
Monitor arterial blood gases, aim to keep pO2 between 50 and 80mmHg
Desired range of monitored pulse oxymeter for infants <34weeks gestation is 88 to 95% but for more mature infants 88 to 100%

10. INTUBATION AND IPPV IPPV- Intermittent Positive Pressure Ventilation
Indications:
Cyanosis that persists in spite of maximal oxygen therapy
Severe recurrent apnoea
Respiratory failure (pCO2 >70 and pH <7.2)

11. CPAP
Continuous Positive Airway Pressure is used to treat preterm infants whose lungs have not yet fully developed such as in RDS or bronchopulmonary dysplasia
It’s functionally similar to PEEP, except that PEEP is an applied pressure against exhalation and CPAP is a pressure applied by a constant flow
CPAP:-
improves survival
decreases the need for steroid treatment for their lungs
decreases the need for IPPV

12. Surfactant ventilator settings
Ventilator rate 60 breaths per minute
Inspiratory time 0.3sec; expiratory time 0.7sec
PEEP 5cm
Oxygen set to maintain saturations of 88 to 95%
Peak inspiratory pressure (PIP) 20-30cm water

13. SURFACTANT ADMINISTRATION
Premature neonates with surfactant deficiency and respiratory distress syndrome have an alveolar pool of about 5mg/kg. Full-term animal models have pools of mg/kg.
Recommended dosages of clinically available surfactant preparations are mg/kg, approximately the surfactant pool of term newborn lungs

14. Rapid bolus administration of surfactant after adequate lung recruitment with 3-4cm of positive end-expiratory pressure (PEEP) and adequate positive pressure may improve its homogeneous distribution.
Most neonates require 2 doses; however, as many as 4 doses, given at 6-hour to 12-hour intervals, were used in several clinical trials.
NB:
Dosages could be given as a rapid bolus or intermittent administration.
Prophylactic doses can be given soon after delivery

15. If the patient rapidly improves after 1 dose, respiratory distress syndrome is unlikely.
Conversely, in infants who have a poor or no response, patent ductus arteriosus (PDA), pneumonia, and complications of ventilation (air leak) should be excluded, especially before subsequent surfactant doses are given.

16. SUDDEN DETERIORATION In spontaneously ventilating:
pneumothorax
failure of oxygen supply
increase in severity of the underlying disease
In a ventilated infant:
endotracheal tube blockage or displacement
mechanical failure with the ventilator
increase in the severity of the underlying lung disease
massive intraventricular haemorrhage
necrotizing enterocolitis, especially if perforation has occurred
patent ductus arteriosus

17. FAMILY PSYCHOTHERAPY
Staff members (preferably a physician and a nurse) should keep the patient’s parents well informed by frequently talking to them, especially during the acute stage of respiratory distress syndrome

18. THANK YOU!!