Luke Tobius, was born at 38+2 weeks gestation. His mother, May Tobius, G4P3, presented to the labour ward at full dilation with the baby's head on view and the presence of thick meconium. Within 3 minutes of arrival on labour ward Luke was born by normal vaginal delivery. His Apgar scores were 5 and 7 at 1 and 5 minutes respectively. He was transferred to the NICU where there was rapid onset of respiratory distress requiring 40% headbox oxygen. Chest x-ray revealed hyperinflation and coarse opacification.
The perinatal history should include:
A comprehensive examination of the baby, including:
In addition to a chest x-ray, investigations would include:
Management will include:
The most likely diagnosis is meconium aspiration syndrome. Treatment for meconium aspiration syndrome is as for respiratory distress, with emphasis on:
Other management strategies may include:
Meconium aspiration syndrome.
The presence of thick meconium in labour, early onset respiratory distress in a term or near term baby, with a chest x-ray revealing hyperinflation and coarse opacification makes the diagnosis of meconium aspiration syndrome the most likely.
Respiratory distress is the generic term used to describe the following clinical signs persisting for more than 4 hours:
Retained foetal lung fluid occurs when either there is an excess of lung fluid or clearance mechanisms are inefficient.
Key Features:
| Acute | Subacute | Chronic |
|---|---|---|
| Cardiopulmonary | ||
| Perinatal asphyxia | Encephalopathy | Neurosensory disability |
| Pulmonary air leak | Consolidation/collapse | Bronchopulmonary dysplasia |
| Patent ductus arteriosus | Lung oedema | Sudden infant death syndrome |
| Pulmonary hypertension | Opportunistic infection | Subglottic stenosis |
| Pulmonary haemorrhage | Chronic obstructive pulmonary disease | |
| Cerebral | ||
| Cerebroventricular haemorrhage | Ventricular dilatation | Hydrocephalus |
| Periventricular leukomalacia | Cysts | Porencephaly |
| Cerebral atrophy | ||
| Gastrointestinal tract | ||
| Necrotizing enterocolitis | Bowel obstruction | Malabsorption |
Assisted ventilation usually consists of continuous positive airway pressure (CPAP) via nasal prongs or face mask or mechanical ventilation (CPPV) via an endotracheal tube. Rarely ventilation is given non invasively via nasal prongs or a face mask. The need for assisted ventilation at birth is determined by condition at birth, birth weight and gestational age and whether mother received antenatal steroids.
An approach to assisted ventilation after birth is:
All infants - intubation, CPPV and surfactant if:
Techniques of mechanical ventilation vary between neonatal units and include intermittent mandatory ventilation, patient triggered ventilation, volume ventilation and high-frequency oscillation. Large infants often struggle or 'fight' the ventilator and benefit from analgesia and sedation or paralysis with a non-depolarizing muscle relaxant.
Exogenous surfactant (natural, synthetic, partially synthetic) administered via endotracheal tube, both in prophylactic (infants < 30 weeks) and rescue modes, has resulted in a 40% reduction in mortality from RDS. Pulmonary air leaks have been dramatically reduced but not so bronchopulmonary dysplasia or patent ductus arteriosus. Exogenous surfactant may benefit selected infants with meconium aspiration, congenital pneumonia and congenital diaphragmatic hernia.
| Congenital Diaphragmatic Hernia | Oesophageal Atresia and Tracheo-oesophageal Fistula | |
|---|---|---|
| Key features | Incidence is 1/2500-5000 births. In the most common type of congenital diaphragmatic hernia (Bochdalek hernia) there is a defect of the left posterolateral part of the diaphragm that allows the contents of the abdomen to herniate into the left thoracic cavity. This limits the space available for the lungs to develop in utero. Right-sided diaphragmatic hernias account for only 15% of such lesions. | Incidence is 1 in 3000 births. This is a congenital abnormality where the midportion of the oesophagus is missing. In most there is an abnormal communication between the lower oesophageal segment and the trachea, called a distal tracheo-oesophageal fistula. About 50% of these infants have other congenital abnormalities, most of which form part of the VATER association (vertebral, cardiac, renal, anorectal and radial abnormalities. Major chromosomal abnormalities are seen in 5%, of which trisomy 18 and trisomy 21 are the most frequent. Many are premature and a history of maternal polyhydramnios is common. |
| Signs/symptoms | The resulting pulmonary hypoplasia creates severe respiratory distress within minutes of birth and in some infants is not compatible with long-term survival. | Any newborn infant who appears to salivate excessively at birth (drooling) should be suspected of having oesophageal atresia. Other symptoms include choking and coughing associated with feeds. |
| Diagnosis | Diagnosis of the condition may be made antenatally on routine ultrasonography. The diagnosis is confirmed after birth by a plain chest X-ray, which shows loops of bowel in the left chest. The heart is displaced to the contralateral side and there is little room available for the lungs. | The diagnosis is confirmed by passing a large, firm catheter, for example a 10 French gauge orogastric tube, through the mouth and finding that it cannot be passed more than about 10 cm from the gums. A plain X-ray of the torso will show gas in the bowel, confirming the presence of a distal tracheo-oesophageal fistula. |
| Treatment | Early treatment involves aggressive cardiorespiratory support and decompression of the bowel. When the child is stable, operative repair of the diaphragm is undertaken. | The child must not be fed; otherwise, aspiration of feeds into the lungs is likely to occur. Initial management involves regular suctioning of the upper oesophageal pouch to prevent aspiration until the tracheo-oesophageal fistula has been divided. The oesophageal ends are anastomosed at the time of thoracotomy to close the fistula. |
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