Respiratory Distress Flashcards
What are the cardinal signs of respiratory distress?
- Persistent tachypnea (>60 breaths per minute)
- Central cyanosis in room air
- sternocostal recession
- expiratory grunting
What are predisposing factors to respiratory distress?
- Preterm delivery
- Underweight for gestational age or wasting
- Fetal distress or failure to breathe well at birth
- Complicated labour
- Clinical chorioamnionitis in the mother
- Elective Caesarian section
What are the respiratory causes of respiratory distress?
- hyaline membrane disease
- wet lung syndrome
- meconium aspiration
- pneumonia
- chronic lung disease
- pneumothorax
- lung hypoplasia
What are the non- respiratory causes of respiratory distress?
Hypothermia Metabolic acidosis Anaemia or polycythemia Patent ductus arteriosus Congenital heart disease Diaphragmatic hernia
What are the two types of infants most at risk for hyaline membrane disease?
Pre term infants and term infants born to poorly controlled diabetic mothers
What 3 factors further inhibit surfactant synthesis?
Hypoxia, hypothermia and metabolic acidosis
What are the clinical signs of hyaline membrane disease?
- features of respiratory distress are apparent at or soon after birth and get worse for 72 hours before improving. Infant is inactive and tends to lie in a frog position
- chest X-ray typically shows an under expanded chest with a fine reticule- granular appearance over both lung fields
What is the dosage of betamethasone to prevent hyaline membrane disease?
2 doses of bethamethasone 12 mg
24 hours apart
What are the aims of management for hyaline membrane disease?
- prevent progressive alveolar collapse
- maintain oxygen says at 86-92%
- keep body temperature and blood glucose concentration within normal limits
- provide adequate nutrition
- maintain paO2 between 7 and 10 kPa
What is hypoxia treated with in hyaline membrane disease? And what needs to be measured when administering this?
Nasal prong CPAP
Arterial oxygen tension and saturation
The inspired oxygen concentration
What is the management of hyaline membrane disease once respiratory distress deteriorates after CPAP is given?
How long does respiratory distress usually take to resolve?
- give surfactant by in- and- out enndotracheal intubation
- intermittent positive pressure ventilation or high frequency oscillation
Usually the respiratory distress had resolved by a week
How do you treat respiratory and metabolic acidosis associated with hyaline membrane disease?
Mild respiratory acidosis is well tolerated and is not an indication for ventilation.
Metabolic acidosis Will usually improve with adequate oxygenation and hydration. severe metabolic acidosis May need correction with 4% sodium bicarbonate given IV very slowly according to the formula: mmol bicarbonate = base deficit x weight x 0.6
What are the complications associated with HMD?
Early: Pneumothorax Periventricular haemorrhage Heart failure due to persistent PDA Pneumonia
Late:
Chronic lung disease (bronchopulmonary dysplasia)
Who is most at risk for wet lung syndrome? What is the pathogenisis?
Infants delivered by elective Caesarian section. It’s attributed to delayed clearing of the fetal lung fluid into pulmonary capillaries and lymphatics after birth.
What are the clinical signs of wet lung syndrome?
Within an hour or two of birth there are features of respiratory distress and the chest is hyperinflated.
Chest X-ray shows increased vascular markings with hilar streaking.
What is the management of wet lung syndrome?
Additional oxygen via nasal catheter or head box is required but usually does not exceed 40%. Most infants improve in 12 - 24 hours. Tachypnea may persist for several days. Does not require admission to intensive care unit
Which infants are at risk for meconium aspiration
It usually follows fetal distress during labour. It is limited to term or post-term infants especially if they are wasted or underweight for gestational age
What is the clinical presentation of meconium aspiration
Inhaled meconium produces areas of emphysema and atelectasis throughout the lungs. The chest is hyperinflated and there is a risk of pneumothorax and pneumomediastinum. A pneumonitis may be caused by chemical irritation of inhaled meconium or by secondary bacterial infection. At birth meconium is present in the mouth and pharynx and may stain the skin, nails, cord and placenta. Poor breathing after delivery is common
What is the treatment of meconium aspiration?
- Remove meconium from the upper airways before the infant starts to breathe
- Nasal CPAP helps to expand the collapsed alveoli and gives better distribution of air in the lungs
- gastric lavage using 2% sodium bicarbonate solution to treat gastritis
- antibiotics only if secondary bacterial infection develops
- steroids are not helpful and may increase the risk of secondary pneumonia
Which organisms are responsible for the majority of early onset bacterial pneumonia?
E. coli and group B haemolytic streptococcus. Chronic fetal infections (syphillis) may cause early onset (congenital) pneumonia
What is pneumonia on day one a result of?
Chorioamnionitis.
Which organisms usually cause nosocomial pneumonia?
Staph aureus, klebsiella, pseudomonas
How does a newborn with pneumonia present?
Poor breathing after delivery, apnoeic spells or features of respiratory distress.
How is a diagnosis of pneumonia confirmed?
It is confirmed by chest X-ray (reticulo-granular appearance over both lung fields). The causative agent may be cultured from the trachea or the blood. In early onset pneumonia due to chorioamnionitis the gastric aspirate at birth contains bacteria and pus cells on gram stain
