respiratory distress in newborn

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Respiratory Distress In Newborn & Mx of surgical condition Dr NIRAV DHINOJA

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Respiratory Distress In

Newborn

&

Mx of surgical conditionDr NIRAV DHINOJA

Imp questions

Gestation : Term or Preterm?????

Weight : SGA or LGA????

Onset : at birth or hours or days after birth????

MEDICAL CAUSES

TTNB – transient tachypnea

RDS(HMD)

Aspiration syndromes

Pneumonia/sepsis

PPHN

CCF

Acidosis

SURGICAL CAUSES

Pneumothorax

Diaphragmatic hernia

TEF

Lobar emphysema

Phrenic nerve paralysis

Pleural effusion

Cystic lesions

Airway obstruction

Nasal –choanal atresia

nasal edema

Oral cavity –macroglossia.

micrognathia,

Glosoptosis

Laryngeal

obstruction –laryngeal web

Subglottic stenosis of larynx

Laryngomalacia

cord paralysis

Airway obstruction

Neck obstruction

Cystic hygroma

Congenital goiter

Tracheal obstruction

Tracheomalacia

TEF

Tracheal stenosis

Lung parenchyma

Aspiration syndrome (MAS)

Respiratory distress syndrome (HMD)

TTNB

Pneumonia

Pleural effusion

Pulmonary hemorrhage

Air leak – Pneumothorax,

Pneumomediastinm

Developmental defects

Agenesis of lung

Hypoplasia of lung

Diaphragmatic hernia

Tracheal agenesis

TEF

Clinical features

Newborn with respiratory distress

usually presents with

Tachypnoea

Chest retraction

Severe Grunting

Cyanosis

Apnoea

Approach to Evaluation

ANTENATAL H/o :

Polyhydramnios(TEF) or oligohydramnios(pulmonary hypoplasia).

Cervical incompetence.

Maternal Illness:

Diabetes(IDM).

PIH(intrauterine hypoxia).

Infections(pneumonia/sepsis).

Maternal medications.

Antenatal Steroids.

Antenatal Ultrasound suggestive of anomaly.

History of Sibling death / similar clinical presentation

in sibling.

DELIVERY

Prolonged / Premature rupture of membranes.

MSAF.

CLINICAL

Term or Preterm.

Time of presentation and progression of Respiratory

Distress.

External congenital anomalies, shape of the

chest(jeune’s syndrome).

Excessive oral secretions(TEF).

Hyperinflation of chest(MAS,CDH).

Position of cardiac apex, Breath sounds,

Transillumination (pneumothorax, CDH).

Normal passage of nasogastric tube

INVESTIGATION

Pulse oximetry :

SaO2.

Fluctuations of SaO2.

Differential SaO2.

Chest X-ray (with gastric tube in place).

Arterial Blood gas.

Echocardiography & CT scan if required.

Downes score

Interpretation

Infants with RDS scores <4 for over 2 hours usually resolve without any problem.

Infants with scores of 4 to 6 have mild respiratory distress.

Infants with scores >6 will develop severe respiratory distress.

Higher scores correlate with decrease in oxygenation and pH.

These scores were studied in infants with respiratory distress syndrome, but they are useful in assessing any newborn with respiratory distress.

Silvermann Anderson score

Interpretation

The parameters assessed by inspection or auscultation of

the upper and lower chest and nares on a scale of 0, 1 or

2.

The higher the score, the more severe the respiratory

distress.

Management Of Surgical

Conditions

Pneumothorax

Pneumothorax can occur in 1 % of all newborns.

Only 10 % of these are symptomatic.

15 – 20 % of pneumothoraces are bilateral.

An infant with lung disease like MAS & HMD, or those

given positive pressure ventilation are more to develop

a pneumothorax.

The compression of the underlying lung and progressive

mediastinal shift to the opposite side result in pulmonary

and hemodynamic changes.

A sudden increase in cerebral blood flow corresponding to

the changes systemic hemodynamics, could cause or

increase the bleed in to the germinal matrix or cerebral

ventricles, especially in premature infants.

The clinical presentation could varied.

It maybe dramatic with severe respiratory

distress, hyper-inflated chest, shift in cardiac

apex, unilateral decrease in breath sounds, and a

positive trans-illumination.

Commonly an infant under treatment for other

cause of respiratory distress would develop a

pneumothorax.

An unexplained increase in heart rate, or gradual drop in

blood pressure in an infant with respiratory distress should

arouse the suspicion of pneumothorax, More so if the

infant is on mechanical ventilator support or required

positive pressure resuscitation.

Screening for pneumothorax by trans-illuminating the

chest of an at-risk infant at regular intervals may be

helpful.

A chest-Xray would confirm the diagnosis.

Incidentally detected asymptomatic

pneumothorax requires no treatment other than

close observation.

Immediate decompression is the rule in all

symptomatic patients.

Aspiration thru a 21G or 22 G scalp-vein needle inserted in

to the 2nd intercostals space in the mid-clavicular line or

5th/6th inercostal space in the mid-axillary line would

temporarily abate symptoms.

Insertion of the intercostals catheter under local

anesthesia in the 6th intercostals space in the mid-axillary

line, connected to an under water sealed drain would

satisfactorily drain out the airleak.

If the infant continues to be symptomatic, despite a

bubbling ICD, think of a pneumothorax on the opposite

side.

If all the clinical features are

exclusively due to the

pneumothorax, the recovery

would also be quite dramatic.

In the presence of an underlying

lung disease, improvement in

symptoms are significantly

influenced by the extent of the

primary disease.

The catheters are clamped when

the ICD has not bubbled for 24

hours.

If there is no clinical worsening,

the infant is observed for a 6 -12

hr period and the clamped

catheters are removed.

Choanal atresia

A infant who is normal and pink when it cries but rapidly develops

respiratory distress becomes cyanosed when it stops crying should be

evaluated for bilateral choanal atresia.

As neonates are obligate nasal breathers, bilateral choanal

obstruction results in their becoming cyanosed when they stop

crying.

An oral airway would often immediately alleviate the symptoms.

Occasionally the presentation would be as respiratory distress while

attempting to breast feed.

CT scan

Diagnosis is suspected when one is unable to

introduce a nasopharyngeal catheter.

CT scan would confirm the diagnosis.

Surgical intervention to alleviate the membranous

or bony obstruction to the choanae would have to

be undertaken with out delay.

Tracheo-esophageal fistula(TEF)

Antenatal history of polyhydroamnios may be available.

Clinical suspicion of TEF must be aroused in an infant who

continues to pour out oral secretion, warranting repeated

oral suction.

There is a high chance of the infant aspirating these

oropharyngeal secretion & aspiration of gastric secretion

through the lower tracheoesophageal communication and

resultaning in pneumonia.

If undetected at the time of delivery presentation could

be as cyanotic episodes associated with feeding,

respiratory distress, abdominal distension in the presence

of fistula, and a scaphoid abdomen in the presence of

pure esophageal atresia.

Prenatal diagnosis of congenital TEFs:

Prenatal ultrasound may reveal polyhydramnios, absence of fluid-filled stomach, small abdomen, distended esophageal pouch.

Postnatal diagnosis of congenital TEFs :

Plain chest radiographs may reveal tracheal compression and deviation.

Absence of a gastric bubble indicates esophageal atresia without a TEF or esophageal atresia with a proximal TEF.

Chest radiography leads to the diagnosis of TEF in most cases of congenital TEF.

Aspiration pneumonia in the posterior segments of the upper lobes may occur secondary to aspiration of the contents from the esophageal pouch or stomach. Recurrent or massive aspiration may lead to acute lung injury in some patients.

Insertion of a nasogastric tube may show coiling in the mediastinum of patients who have concomitant esophageal atresia. This finding is diagnostic of TEFs associated with esophageal atresia.

Contrast studies are seldom required to confirm the diagnosis.

These studies have the risk of aspiration pneumonitis and pulmonary

injury.

If the contrast study is performed, 1-2 mL of barium is instilled through an

8F catheter placed into the esophagus. Chest radiographs are taken in the

lateral decubitus position as well as the anteroposterior position to detect

spilling of the contrast into the trachea.

Use of multidetector-row CT scans have made 3-dimensional (3D) displays

of many organs and structures.

Presence of TEF is correctly diagnosed with CT esophagography.

Treatment

The infant should be kept nil by mouth.

Nutrition, fluid and electrolytes requirements being maintained intravenously.

The baby should be nursed in a 15 – 30 degrees head elevated prone or lateral

position.

The upper pouch should be continuously drained, preferably with minimal

continuous suction.

Once stabilized the infant must be transferred to the surgical team for further

management.

Surgical managment

In healthy Newborn – primary repair.

In Newborn with comorbidities like pneumonia, low birth

weight or respiratory distress syndrome staging of surgery

is done.

1st stage –

Tracheostomy

Gastrostomy tube.

Feeding jejunostomy.

Exteriorisation of upper pouch and minimal continuous suction.

2nd stage –

Definitive surgery for fistula – division & closure.

Approach –

Right side thoracotomy in lateral decubitus position.

Thoracoscopy.

Congenital diaphragmatic hernia(CDH)

• Antenatal USG is helpful in identifying CDH.

• Rule out “diaphragmatic hernia” in all neonates presenting

with respiratory distress at birth with a cardiac impulse

better felt in the right hemithorax.

• Scaphoid abdomen.

• Radiograph of the chest would confirm the diagnosis.

Management

If warranting resuscitation at the time of delivery, positive pressure ventilation

through a mask is discouraged and ventilation is commenced after directly

intubating the infant.

The associated hypoplasia of the ipsilateral lung, compression of the contralateral

lung, and the associated hypoxemia, acidosis and hypercapnia result in these

infants having a significant degree of PPHN.

Immediate emergency surgery is no longer recommended.

Instead a period of stabilization with adequate fluid support, maintenance of

blood pressure, control of PPHN and ventilatory stability have ensured better

surgical outcome.

The primary aim of respiratory management is to ensure adequate

oxygenation and avoiding acidosis.

Various strategies of conventional and high frequency ventilation are

adapted for attaining this.

Aim is to try and lower the PaCO2 to acceptable low values by

hyperventilation, providing adequate FiO2 and Mean Airway pressure (MAP)

for oxygenation.

An oxygenation index (OI) greater than 20 at 6 hrs of life, was associated

with higher mortality.

Surgical correction is mandatory.

Approach for surgical repair :

Abdominal subcostal.

Thoracotomy.

Thoracoscopy.

The major determinants of the final out come would be prenatal factors that

affect the development of pulmonary parenchyma, pulmonary vascular bed

and surfactant system.

Postoperative care would involve continued ventilator support, strategies to

manage the associated PPHN and if warranted extracorporeal membrane

oxygenation (ECMO).

Follow-up of the survivors is necessary to evaluate and manage respiratory

problems and tackle issues of those of feeding, growth and development.

Congenital lobar emphysema

This is a rare but well recognized cause for an infant presenting with respiratory

distress anytime within the neonatal period.

The infant would present with tachypnea, recessions, cyanosis and hyperinflation of

the affected side.

Breath sounds on the affected side may be diminished.

A differential diagnosis of pneumothorax may be considered.

A chest X-ray would show hyperinflation of the affected lobe, mediastinal shift to

the opposite side and on closer examination would reveal the lung markings --- thus

differentiating this from pneumothorax.

Definitive surgical treatment - lobectomy.

Intranasal tumours, laryngeal webs, laryngeal cysts,

laryngomalacia are few of the anomalies of the upper

airway that could present as respiratory distress in the

neonatal period.

Rare developmental anomalies like cystic adenomatoid

malformation of the lung, congenital pulmonary

lymphangectasia etc. could present as neonatal

respiratory distress, requiring surgical intervention .

The outcome of these conditions depends on the extent of

lung involvement and association of other congenital

anomalies.