1. Respiratory disorder
Samah Suleiman
23/3/2006

2. Introduction
At birth major cardiopulmonary changes take place in order to prepare the baby for extra uterine existence
The fluid in the fetal lung is rapidly replaced by air, associated with lung inflation and increased oxygenation there is a marked decrease in the pulmonary vascular resistance, with consequent increased pulmonary blood flow and closure of the ductus arteriosus, foramen ovale and ductus venosus

3. Respiratory distress
Is a general term used to describe respiratory symptoms
It is assessed clinically by the following signs:-
Tachypnoea (R.R more than 60/ min)
Expiratory grunt: the infant expires against a closed glottis, which maintains a higher residual lung volume, thus preventing alveoli from collapsing (preterm infant)

4. Chest retraction: this may be intercostal, lower costal, sternal or substernal
Flaring of the ala nasae associated with infants used accessory respiratory muscles
Cyanosis which is central (nitrogen wash out test to differentiate if the problem is cardiac or respiratory)
Bilateral decrease air entry

5. diagnosis Full clinical history Physical examination
Appropriate investigation
Chest X-ray
Perinatal history
Vital signs

6. Investigations Bacteriological culture Viral culture Full blood count
Lecithin/ sphingomyelin (L/S) ratio
Chest transillumination with a cold light source if pneumothorax suspected
Passage of NGT

7. Treatment Supportive care:- Vital signs Keep the baby warm
I.V.F and nutrition (TPN)
Keep monitoring
Oxygen:-
Is useful and life saving therapeutic agent but is potentially dangerous especially in preterm

8. Baby, may cause retinopathy and bronchopulmonary dysplasia
Fluids:-
Shouldn’t be breast or bottle fed
With mild RDS gavage feeding may be adequate
With sever RDS, IVF may be adequate

9. Acid-base studies:-
If respiratory acidosis is sever (pH less than 7.2) assisted ventilation may be necessary
For sever metabolic acidosis an infusion of sodium bicarbonate may be indicated

10. Mild respiratory distress
Color presence of central cyanosis
Chest retraction
Grunt and flaring of the ala nasae
Heart rate hourly recorded
Respiratory hourly recorded
Temperature q 4hrs
B.P q 4hrs

11. Moderate to sever respiratory distress
Heart rate monitoring with alarm system for bradycardia
respiratory monitoring with alarm system for apnea
Pulse oximetry
Regular ABGs
Hourly B.P
24hrs fluid balance chart

12. Umbilical artery catheterization
For regular ABGs estimations
Indication for insertion of an umbilical catheter:-
Infant less than 1000 gm
Infant require intensive care
Infant with increasing RDS
Infant with sever recurrent apnea

13. Transient tachypnea of the new born (TTN)
It is RDS type 2
Occur in 1-2% of all newborn infants
Is usually benign and self limiting

14. pathogenesis
Most of the fetal lung fluid is squeezed out during descent through the birth canal or within the first few breaths after birth, but some is reabsorbed into the pulmonary capillaries and lymphatic
In these cases retained fluid causes respiratory distress

15. Predisposing factors Prematurity Heavy maternal analgesia
Birth asphyxia
C\S
Breach presentation
Male sex
Hypoproteinaemia and Polycythemia
Excessive fluid administration to the mother in labor

16. treatment Doesn’t usually require respiratory support
Extra inspired oxygen
Regular blood gas measurement
Usually improved within 48hrs
Pulmonary hypertension or pneumothorax may have developed

17. RDS reliving factors
Hydrocortisone (give 2 doses 4mg q 12hrs and before 4-8hrs of labor)
Any stress
IUGR
Pre-eclampsia

18. Respiratory distress syndrome (hyaline membrane disease)
Occurring in preterm infants due to a lack of surfactant in the alveoli
Occur in 1% of all births
Although there have been a number of recent advances in the management of premature delivery, including suppression of labor, estimation of L\S ratio and the use of steroids

19. Predisposing factors Prematurity Infant of a diabetic mothers
Ante partum Hge
Second twin
Hypoxia, acidosis, shock
Male sex
C\S
hypothermia

20. pathogenesis
The lack of surfactant results in alveoli remaining unexpanded (atelectatic) and gas exchange is impaired
Surfactant is a phospholipid secreted by the type 2 alveolar cells of the lung and is stored in lamellar bodies
The major active component is lecithin, but other phospholipids and protein must be present for full activity

21. These surface-active agents are released into alveoli, reducing the surface tension and helping to keep the alveoli open
Lung maturity is assessed by measuring the L\S ratio
An L\S ratio less than 1.5 predict a high risk of RDS (70% incidence)
An L\S ratio of predicts a 40% risk of developing RDS

22. Mature ratio more than 2 indicates a very small risk unless the mother is diabetic
Surfactant is secreted into the fetal lung at 3o-32 wks gestation

23. Clinical features
The signs start immediately after birth or become obvious in the first 6hrs of life
The infant lies in a frog-like position and may have difficulty with copious pharyngeal secretions
Expiratory grunt may diminish and prolonged apnea may occur
The infant is oliguric initially and has evidence of increasing peripheral edema

24. radiology
Ground glass
Air bronchograms
Poorly inflated lung

25. Treatment Oxygen:- Maintain the pao2 within the normal range
Increasing the inspired oxygen concentration
In sever cases respiratory support may be necessary

26. Chest physiotherapy:-
Regular position changes
Air way suctioning to reduce the risk of mucus retention
Active chest percussion and cupping
Physiotherapy shouldn't be employed for at least 24hrs after surfactant instillation
Antibiotics:-
Broad-spectrum antibiotics

27. Surfactant replacement therapy:-
Exogenous surfactant is administered via the endotracheal tube either to infants with established RDS or as a prophylaxis in high risk preterm infants
It is general practice to give at least one dose of surfactant down the endotracheal tube as soon as RDS is diagnosed then put the baby on mechanical ventlation

28. Meconium aspiration syndrome
Is a serious and potentially preventable cause of respiratory distress in the newborn
Meconium staining of the amniotic fluid occurs almost always in full term or post term infants
The passage of Meconium often indicates fetal distress

29. Clinical features
Infant is born covered in Meconium stained liquor and has Meconium staining of the umbilical cord
Hyper inflated chest
Respiratory distress
Cerebral irritability

30. pathogenesis
Causes plugging of the airways with consequent atelectasis
Meconium is irritating to the airways causing a chemical pneumonitis and secondary bacterial infection

31. Prophylactic management
Once the head crowns, and before the shoulder are delivered, the oropharynx should be suctioned
Transfer the baby to the resuscitation trolley
In depressed infant intubeted is needed
If the baby is healthy transfer to mother

32. Treatment Humidification of inspired oxygen
Postural drainage positioning
Suctioning of airways and chest percussion
Antibiotic