Clinical approach to Respiratory Distress in Newborn. Indian J Pediatr (Supplement- optimum pulmonary care of neonates) 2003;70: S53 – S59

CLINICAL APPROACH TO RESPIRATORY DISTRESS IN NEWBORN

K. K. Diwakar MD.

Head, Neonatal Division,

Professor, Department of Pediatrics,

Kasturba Medical College, Manipal,

Karnataka – 576119.

Correspondence:

K. K. Diwakar MD.

Head, Neonatal Division,

Professor, Department of Pediatrics,

Kasturba Medical College, Manipal,

Karnataka – 576119

Tel: 08252 – 571201 ext 22466

FAX: 08252 – 570061 attn: KK Diwakar, NICU.

e-mail: krishnadiwakar@mail.fulbrightweb.org

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ABSTRACT

Respiratory distress is a common reason for a neonate seeking medical attention. The

clinical features of tachypnea, intercostals retractions, grunting or cyanosis could be the

manifestations of a variety of etiological causes. Both pulmonary and extrapulmonary

causes could present as tachypnea and respiratory distress. While conditions like Hyaline

membrane disease (HMD) is seen more in premature infants, others like Meconium

Aspiration Syndrome (MAS) considered a disease of the more mature infant. Infections

and structural anomalies like Tracheo-esophageal fistula (TEF)and Congenital

Diaphragmatic Hernia (CDH) are common in both term and preterm infants. Stabilization

of the infant and early recognition of the etiology helps in minimizing complication and

ensuring appropriate definitive therapy. An overview of a few common cause of

respiratory distress in the newborn is being discussed in this article.

Key words: Respiratory Distress, Newborn.

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Respiratory distress is a common cause of admission of a Neonate in the intensive care

unit. 1, 2 .The clinical picture of a neonate with varied combination of tachypnea,

retractions, nasal flaring, grunting and cyanosis constitute a familiar scenario in a

neonatal intensive care unit. When faced with a neonate with respiratory distress it

becomes necessary to compartmentalize the management into an initial phase focusing on

the degree of respiratory compromise, resuscitation of the neonate and optimizing its

tissue oxygenation, and a planned subsequent phase to clarify the nuances of etiology,

definitive management and follow up.

The weight and gestation of the infant and the degree of respiratory compromise would

be the key factors to decide the level of care the infant would require. While infants of

lower weight and gestation would require more advanced facilities, larger infants can

often be managed at smaller centers. Simple clinical scores like the Downes’s score 3 if

meticulously documented at 30 – 60 minutes intervals are very useful to determine the

progression of the respiratory distress. The importance of such an evaluation would be

invaluable to plan referrals in the resource-limited environment of developing countries,

where structured neonatal transportation facilities are unavailable. A clinical evaluation

should whenever possible include oxygen saturation (SaO2) assessment by Pulse

Oximetry. SaO2 below 88 % would indicate hypoxia. While SaO2 between 88 – 94 %

would be normal in the more premature neonates, higher SaO2 values are the norm in

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term infants. Increasing requirement of inspired oxygen, to maintain ‘normal’ SaO2

would therefore be an ominous sign.

While the clinical presentation could be similar, the etiology, prognosis and management

of the patients presenting with respiratory distress could be varied and diverse. The

‘distress’ of the infant could be attributed to pulmonary or extra-pulmonary disorders.

A functionally normal lung could be at times called upon to work at a capacity far

exceeding natural level, in order to compensate for abnormalities of other systems. eg. In

the presence of metabolic acidosis, cardiac disease or abdominal distension. The extra

effort required of lungs enclosed in a compliant rib-cage could manifest as tachypnea,

chest retraction, prominence of accessory muscles of respiration and resultant fatigue

leading to further de-compensation. The definitive management of such an infant would

naturally be based on the treating the primary ‘extra-pulmonary etiology.

It must be reinforced that the initial management of all infants presenting with respiratory

distress is aimed at preventing hypoxia, hypercapnia and acidosis in the newborn. The

methods adapted for this could vary from oxygen supplementation to various strategies of

mechanical ventilation.

Despite a relatively uniform approach to the initial management, one must realize that

procrastination and delay in instituting definitive therapy would result in adverse

outcome. For example, an infant with tension pneumothorax could rapidly deteriorate

despite the transient improvement of initial therapy, if the pneumothorax is not

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evacuated. Similarly, repeated aspiration pneumonia would contribute to poor surgical

outcome in patients with delayed diagnosis of tracheoesophageal fistula (TEF). Therefore

a definite diagnosis is mandatory for successfully managing infants with respiratory

distress.

The cause of for neonatal respiratory distress could be broadly classified as

1) Causes affecting respiration at alveolar level: HMD, Pneumonia, Meconium

Aspiration Syndrome, Pneumothorax, pulmonary hemorrhage, PPHN, TTN

2) Structural anomalies of respiratory tract: eg Choanal Atresia, Tracheo-esophageal

fistula, Congenital Diaphragmatic hernia, Congenital Lobar Emphysema.

3) Extrapulmonary causes: eg. Bone defects of the chest wall, Congenital heart

disease, Metabolic acidosis.

Is the respiratory distress and cyanosis due cardiac or pulmonary problems? Is the

distress an effect of metabolic acidosis due to some other cause?

Differentiating a cardiac from pulmonary cause is often easier said than done. The

radiological picture of total anomalous pulmonary venous connection (TAPVC) or that of

a hypoplastic left heart with pulmonary edema would often resemble that of common

pulmonary causes for neonatal respiratory distress. Radiological differentiation becomes

even more difficult in the presence of an under expanded lung or a rotated view! It used

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to be believed that ‘hyperoxia test’ done by ventilating the infant for 20 minutes in 100%

oxygen would help differentiate the pulmonary from cardiac causes. While an arterial

oxygen concentration (PaO2) greater than 200 - 250 torr favours a pulmonary cause,

lower values do not positively indicate a cardiac etiology. The availability of

Echocardiography has thankfully made the diagnosis of a cardiac disease immeasurably

easier.

Tachypnea and ‘respiratory distress’ could be a presentation of metabolic acidosis. Renal

disease, inborn errors of metabolism (IEM) and late metabolic acidosis are forerunners of

a long list of causes for metabolic acidosis. While a history of oligohydraminios,

poor urine output or urine stream could suggest a renal disease, a history of sibling death

or sibling with similar clinical presentation would favour IEM. A low birth weight infant

on ‘cow’s milk’ supplementation should arouse the suspicion of late metabolic acidosis.

Chest X-ray unexplainably normal to justify the degree of tachypnea should alert one to

the possibility of metabolic acidosis being the cause for the distress. SaO2 is usually

normal in these patients. Arterial blood gases would confirm metabolic acidosis.

Biochemical evaluation for renal failure, renal tubular acidosis (RTA) and IEM constitute

an essential part of managing such patients.

Pulmonary disorders that manifest in the newborn are usually related to immaturity of the

lung, events that occurred in the perinatal period, or a result of congenital

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malformations 4 . The role of history in diagnosing the disease can never be

overestimated. It could be confidently said that the pulmonary causes for respiratory

distress are far commoner than the ‘extra pulmonary’ ones.

The gestation of the infant is probably the single most important factor that influences our

clinical outlook. While structural anomalies and pneumonia are common in both term and

preterm infants, conditions like Hyaline membrane disease is almost an exclusive disease

of the premature infant. Meconium aspiration on the other hand is almost always seen in

term infants. (Table 1). Some of these conditions are being briefly discussed.

HYALINE MEMBRANE DISEASE

This is the commonest respiratory problem of a premature infant . Nearly 80 % of infants

less than 28 weeks develop RDS compared to about 20 % among those between 33 – 34

weeks gestation. 4 . The increased use of antenatal corticosteroids, have definitely shown

to decrease the incidence and severity of HMD 5 .

Factors like poorly controlled diabetes in the mother, fetal or perinatal asphyxia,

anterpartum hemorrhage in mother and multiple pregnancies 6 increase the chances of

RDS in the neonate.

The picture of rapidly progressing respiratory distress, manifesting with tachypnea,

expiratory grunt, intercostals recession, active accessory muscles of respiration and

cyanosis in a premature infant would highlight a diagnosis respiratory distress syndrome.

Often the infant is born with a good cry. This forced expiration thru a partially closed

glottis generates significant distending pressures to open up most of the alveoli. The

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inadequacy of surfactant however results in progressive alveolar collapse. The rapidity of

the collapse and the efficacy of respiratory efforts of the infant determining the

progression and severity of the clinical features. It is therefore easy to understand the

reason for very premature or inadequately resuscitated infants and neonates with severe

surfactant deficiency to present immediately after birth with cyanosis and often as

respiratory failure.

By 72 to 96 hrs of postnatal age the infant would start generating its own surfactant to

increase the compliance of the lung, thereby resulting in natural recovery. Preventing the

progression of alveolar collapse during this intervening period therefore forms the basis

of all treatment. A heavier less premature infant could probably sustain its alveolar

surface area by its own respiratory effort till this dramatic natural turn about of events

occur by 72 to 96 hrs of life. More often than not mechanical ventilator support and

surfactant replacement are required to tide over the tumultuous initial days of this

surfactant deficiency state.

PNEUMONIA

Indian literature attributes pneumonia as the commonest cause for neonates presenting

with respiratory distress. 2, 7 . Pneumonia could be acquired due to a transplacental spead

of virus or bacteria, or acquired in the perinatal or post natal period. A detailed history to

seek out maternal infection or Premature rupture of membranes would therefore be

invaluable 8 .

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One must always hasten to rule out pneumonia in an infant presenting beyond the 1st few

days of life with Tachypnea and difficulty to feed. A decrease in the normal activity of

the infants as noticed by the mother would most certainly reinforce this suspicion. Early

onset pneumonia is very difficult to distinguish from conditions like HMD – more so in

the premature infant. While radiological evaluation could help differentiate pneumonia

from other conditions, in some cases like group B streptococcal pneumonia even this

becomes virtually impossible. Its this authors personal observation systemic features like

poor perfusion, metabolic acidosis and altered glucose homeostasis are more common in

pneumonia than in hyaline membrane disease. Another clue could be the excessive and

thick endotracheal secretion in the 1st day of life --- a feature that is almost never seen in

infants being ventilated for hyaline membrane disease.

Early antibiotic therapy with a ‘Penicillin + Aminoglycoside’ combination, still

continues to be the most accepted line of therapy. It must be reinforced that intravenous

antibiotics must be commenced without delay. It’s the practice to collect blood samples

for investigations including blood culture as soon as the infant is admitted and thereof

immediately give the first dose of antibiotics as per the policy of the treating unit.

Antibiotics can subsequently be tailored according to the culture and sensitivity pattern of

the isolates. Supportive therapy with inotropes and ventilator support must be initiated

based on the clinical condition of the infant. These play very significant role in the

survival of the infant.

MECONIUM ASPIRATION SYNDROME:

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Any infant who passes meconium in-utero is at risk for developing meconium aspiration

syndrome (MAS). While 10 – 15 % of all babies could pass meconium before birth, its

rare before 37 weeks 9. The passage of meconium could at occasions be an effect of fetal

hypoxemia. Occasionally pre-term infants over 34 wks of gestation may pass meconium

inutero. The clinical features of these infants are the same as those seen in term infants 4.

Therefore a history of meconium stained amniotic fluid is mandatory before attributing

the respiratory distress of the neonate to meconium aspiration syndrome.

The consistency of the meconium, adequacy of oro-pharyngeal suction before delivery of

shoulder, associated perinatal asphyxia warranting active resuscitation have all been

shown to influence the severity of meconium aspiration syndrome 9. The aspirated

meconium can completely or partially block the conducting airways leading to segmental

or sub-segmental collapse of the lung. The partial block could function as a ‘ball-valve’

leading to emphysematous changes in the area distal to the obstruction. Rapidity of the

resultant distention could lead to airleaks manifesting as pneumothorax.

The immediate respiratory distress seen in an infant who has aspirated meconium can

therefore easily be attributed to the ‘mechanical’ effects of meconium. However over the

next few hours, diffuse inflammatory responses occur throughout the lung leading to a

picture of ‘chemical pneumonitis’ 9. We have, not uncommonly, noticed such a picture

developing even in infants born through thin MSAF who were asymptomatic in the initial

period after delivery.

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The progressive ventilation /perfusion mismatch and inflammatory responses of MAS

can lead pulmonary vasoconstriction resulting in persistent pulmonary hypertension of

the newborn (PPHN), with its additional morbidity.

The approach to management would be to anticipate MAS in all infants with MSAF.

At Delivery: A good suction of the pharynx before delivery of the shoulders would

significantly reduce the chances of meconium aspiration. It was the recommendations of

the American Academy of Pediatrics and American Heart Association 10 to undertake

endotracheal suction in all infants if there was a (1) Evidence of in utero fetal distress (2)

Neonate is depressed or requires positive pressure ventilation in the delivery room (3)

Meconium is thick, including moderately thick or particulate in nature (4) if obstetric

pharyngeal suction was not performed. However reservations have been expressed about

undertaking endotracheal suction in a vigorously crying infant, even in the presence of

thick meconium 11.

Subsequent management: This phase of management is to evaluate the progression of

MAS and to detect and treat promptly the complications like pneumothorax and PPHN.

An X-ray of the chest might show patchy non-homogeneous opacities often confluencing

towards the mid-zone, with evidence of segmental or subsegmental collapse and areas of

hyperaeration. The presence of a pneumothorax must always be looked for. Occasionally

the X-ray taken immediately after birth could look apparently normal, but a subsequent

film taken over the next 12 – 24 hours might show diffused haziness, non-homgeneous

opacity --- probably reflecting the occurrence of ‘chemical pneumonitis’. Infants are

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more often than not symptomatic during this period. Irrespective of the controversies of

endotracheal suction, its best not to forget that even a vigorously crying infant can

develop all the meconium associated morbidity. It has therefore been our practice to

observe all infants born thru MSAF for at least 24 hrs, keeping an hourly record of the

Downe’s score 3 and continuously monitoring the SaO2 by pulseoximetry.

An increasing respiratory distress would imply that the pulmonary functions have been

compromised by the ‘mechanical’ effects of meconium or due to the development of

chemical pneumonitis. Occurrence of pneumothorax must always be anticipated. Efforts

to rule out pneumothorax must be undertaken especially when, an apparently normal

infant with minimal tachypnea, shows increasing respiratory distress, often after an

episode of vigorous and active crying. A fibre optic source of light is often used to detect

pneumothorax by transilluminating the chest. While a positive transillumination is

suggestive of pneumothorax, one must remember that this test could be negative in term

infants with ‘thicker’ skin. A chest X-ray would confirm the presence of pneumothorax.

A progressive increase in the clinical score would undoubtedly be the most practical and

cost effective way for continuous evaluation. Increasing oxygen demand and a worsening

Downes’ score are ominous signs of a progressive disease.

Fluctuations in the oxygen saturation with the same Fi02, in a quiet infant should arouse

the suspicion of pulmonary vascular instability. Such infants must be monitored more

carefully, with arterial blood gases from an indwelling arterial catheter. A higher ambient

Fi02 could reduce the chances of hypoxemia with its accompanying risk of pulmonary

vasoconstriction. 4. Progressive hypoxia, increasing oxygen demands, metabolic or

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respiratory acidosis, or hypercapnia, should be taken as indications for initiating

mechanical ventilation. Its best to prevent an infant from progressing to established

PPHN.

Antibiotics are usually not warranted. It is however a common practice of doctors to

commence antibiotics, in the presence of abnormal chest-X-ray or respiratory distress 6.

This is probably done keeping in mind the differential diagnosis congenital pneumonia.

Antibiotics are discontinued with in 48 – 72 hrs if the respiratory distress settles or if

investigations are not suggestive of infection.

An uncomplicated MAS normally recovers over 48 – 72 hrs, rarely being symptomatic

beyond the 1st week of life.

PNEUMOTHORAX

Pneumothorax can occur in 1 % of all newborns 12 though 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 pressure 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 12, especially in premature infants.

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The occurrence of a pneumothorax must be frequently evaluated in all at risk infants.

The clinical presentation could varied. It maybe dramatic with severe respiratory distress,

hyperinflated chest, shift in cardiac apex, unilateral decrease in breath sounds, and a

positive transillumination. Not uncommonly an infant under treatment for other cause of

respiratory distress would develop a pneumothorax. The progression could be fairly

gradual. 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 transilluminating the chest of an at-risk infant at regular

intervals have been incorporated in the standard protocol of most neonatal intensive care

units.

A chest-Xray would confirm the diagnosis. While the 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 while

awaiting preparations for intercostals drain insertion. 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. A negative suction

of 10 – 15 cms of water is often applied to the drainage bottle. In the absence of

availability of controlled suction, a ‘vacuum breaker’ bottle with a 10 – 15 cm water

level can be connected between the ICD bottle and the suction apparatus. If the infant

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continues to be symptomatic, despite a ‘bubbling’ ICD, think of a pneumothorax on the

opposite side! It must be remembered that if all the clinical features are exclusively due

to the pneumothorax, the recovery would also be quite dramatic. However in the presence

of an underlying lung disease, improvement in symptoms are significantly influenced by

the extent of the primary disease.

It is worthwhile to maintain an hourly chart to document the bubbling of the ICD.

The catheters are clamped when the ICD has not bubbled for 24 hours. Should the infant

deteriorate, the clamp is release to see if there had been any fresh accumulation of

pneumothorax.. If there is no clinical worsening, the infant is observed for a 6 -12 hr

period and the clamped catheters are removed.

PULMONARY HEMORRHAGE

Pulmonary hemorrhage or massive pulmonary hemorrhage in the newborn is not an

uncommon manifestation. In majority of cases it’s a manifestation of massive pulmonary

edema. Its seen more often in low birth weight infants. A shunt thru a persistent ductus

arteriosus or fluid load could be the main cause of pulmonary hemorrhage in premature

infants. We have seen SGA and growth retarded infants presenting with pulmonary

hemorrhage. Multiple factors could be contributing to pulmonary hemorrhage in the

severely growth retarded infant. Hypothermia, hypoglycemia, thrombocytopenia and

sepsis are a commonly encountered combination. The clinical presentation could range

from mild tachypnea to severe respiratory distress depending of the severity of the

hemorrhage and the ability of the infant to generate distending pressure. A grunt in a

growth retarded infant often manifesting beyond the first few hours of life should always

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arouse the clinical suspicion of pulmonary hemorrhage. The relatively normal activity of

the infant and “ability to suck at the breast” in the near term infant, often contributes to

the complacency seen in detecting this condition.

Early management with ventilator support with a continuous positive airway pressure

(CPAP) of 6 – 8 cm or intermittent positive pressure ventilation with high PEEP, would

effectively control the hemorrhage. More severe the hemorrhage more complicated and

less gratifying becomes the ventilator management, with mortality being proportionate to

the severity of the bleed and general condition of the infant.

If the hemorrhage is due to conditions like PDA, definitive treatment of medically or

surgically closing the ductus must be undertaken. .

TRANSIENT TACHYPNEA OF THE NEWBORN (TTN)

This is a well recognized entity, attributed to delay in fetal lung fluid clearance. This is a

transient phenomenon usually lasting for 6 – 24 hrs, 4 manifesting with increased

respiratory rate, occasionally accompanied by other features of respiratory distress like

grunt and cyanosis. Infants rarely require more than 40% Oxygen.. Occasionally the

clinical features could persist for 2- 5 days. However under such circumstances it would

be more prudent to search for other cause for the respiratory distress. The radiographic

findings are non-specific and include prominent vascular markings, pleural and

interstitial fluid and prominence of the interlobar fissure 6. The final diagnosis of TTN is

always considered after EXCLUDING all other cause for a similar presentation.

PERSISTENT PULMONARY HYPERTENSION OF THE NEWBORN (PPHN)

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Persistent pulmonary hypertension of the newborn is one of the most challenging

conditions of neonatal care. The in-utero status of high pulmonary vascular resistance

starts to drop the first cry of the normal infant, a rapid drop seen with in the first minute

of birth. The drop in pulmonary pressures continues to occur at a fast pace over the first

24 hrs and then at a more gradual pace up to the 7th – 10th post natal day 13. Any factor

(TABLE 2) hampering this drop in pulmonary vascular resistance could ensure that the

infant continues to retain ‘in-utero’ features of circulation with its ‘right to left’ shunt

with the resultant associated hypoxemia and cyanosis.

PPHN should be always considered when an at-risk neonate presents with cyanosis often

being referred from a peripheral hospital as ‘congenital cyanotic heart disease’. Often the

clinical presentation could be dominated by the features of the precipitating causes like

MAS or Pneumonia. This author feels that under such conditions, hypoxemia

disproportionate to the radiological picture would be a good clue to suspect PPHN.

Echocardiography could confirm the suspicion.

Once a diagnosis of PPHN is made, the significance of this labile condition and the high

associated mortality must be recognized and respected. A dictum of minimal handling,

continuous measurement of oxygen saturation (SaO2) by pulse-oximetry or

trancutaneous PO2 (TcPO2) monitoring, high ambient oxygen, and arterial blood gas

assessment thru an indwelling catheter, maintenance of blood pressure and fluid and

electrolyte balance, form the sheet anchor of management. Occasionally SaO2 difference

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greater than 10% between the right hand and the lower limbs is seen if the PPHN results

in a right to left shunt thru a persistent ductus ateriosus.

High Fi02 4, 13 contributes to the gradual reduction of the pulmonary vascular resistance.

Swings in SaO2 or TcPO2 in a quiet infant without any changes in FiO2 is a good

indicator of significant pulmonary vascular lability. Such a labile vasculature could

rapidly constrict to an ‘irreversible’ state under adverse circumstances. Its must therefore

be remembered that the FiO2 would have to be weaned very slowly, often at 1-2 % every

one – two hours. A more rapid or erratic weaning strategy could lead to a

disproportionate drop in the PaO2, due to the extremely labile pulmonary vascular

physiology. The resultant hypoxemia would further worsen the vasoconstriction and

elevate the pulmonary pressure --- leading to a progressive deterioration of the infant.

If the oxygenation of the infant continues to deteriorate varied ventilator strategies,

addition of inhaled Nitric Oxide (iNO) or ECMO might have to be resorted to. Specifics

of these methods would be beyond the purview of this article. Infants would often have to

be transported to advanced centers for these modes of treatment.

Transporting a sick infant is a specialized task undertaken by trained neonatal transport

teams. In most developing countries such transport facilities are unavailable. It is

therefore best to anticipate this eventuality and prepare oneself in advance. This author

recommends a dictum of COME for transporting these infant.. Communicate with the

referral hospital well before transferring the patient; Ensure appropriate Oxygen delivery

to the infant during transport; Minimal handling of infant during transport; Evaluate the

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clinical condition during transport, preferably with pulseoximetry and cardio-respiratory

monitors.

It should be appreciated that adequate ambient oxygen 4 could significantly prevent the

labile pulmonary vasculature of the at-risk infant from progressing to an established stage

of PPHN.

While an infant treated for PPHN often has normal pulmonary functions at one year of

age, the over all outcome is influenced by the etiological cause, duration and mode of

therapy required.

STRUCTURAL ANOMALIES

Most of these conditions would come under the purview of surgical management. Early

recognition of these entities would undoubtedly ensure better management.

Choanal atresia: Bilateral choanal atresia warrants mention here due to its interesting

presentation. 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. Residents attending the delivery would be the first to be exposed

to this perplexing presentation. 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.

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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)

While a detailed discussion would be beyond the purview of this article, it must be

remembered that an early recognition of this condition would dramatically influence the

therapeutic outcome. An antenatal history of polyhydraminos may be occasionally

available. A clinical suspicion of TEF must be aroused in an infant who continues to

‘pour out oral secretion’ warranting repeated oral suction. Esophageal atresia associated

with the proximal tracheo esophageal connection, would result in the inability of the to

swallow its oral secretions. While there is a high chance of the infant aspirating these

oropharyngeal secretion, aspiration of gastric secretion through the lower tracheo-

esophageal communication and resultant pneumonia would further contribute to the

morbidity. 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.14 .

Radiographic evaluation with a ‘gastric’ tube would demonstrate the absence of the tube

in the stomach with the tube getting coiled up at the point of obstruction. Instilling about

5 – 10 ml of air thru the tube would make it easy to observe these coils of the tube against

the air in the esophageal pouch – obviating the necessity of a radio-opaque dye. The

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presence of a ‘gastric bubble’ is due to the movement of air into the stomach thru the

lower tracheo-esophageal connection.

The infant should be kept nil by mouth, with 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. The surgical management could

vary between an immediate definitive correction OR a feeding gastrostomy with

exteriorization of the upper pouch followed by corrective surgery after a few months.

These options are based on the anatomy of the anomaly, the general condition of the

infant and policies of individual surgical units.

It is not uncommon for other VACTERL group of congenital anomalies to be associated

with TEF.

CONGENITAL DIAPHRAGMATIC HERNIA (CDH)

Survival of patients with Congenital diaphragmatic hernia have gradually improved over

the years. Antenatal diagnosis of CDH has made anticipatory management at delivery

and a planned subsequent management a welcome reality. It has been the traditional

teaching to rule out “diaphragmatic hernia” in all neonates presenting with respiratory

distress at birth with a cardiac impulse better felt in the right hemithorax. The only

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differential diagnosis would be a left sided pneumothorax, as rarely does a complex

congenital heart disease with dextrocardia present in such a manner. Radiograph of the

chest would confirm the diagnosis.

If warranting resuscitation at the time of delivery, this is one of two conditions, the other

being MSAF, where positive pressure ventilation thru 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. No longer is immediate emergency surgery 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. It was the aim 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. A modified ventilation index (MVI) greater than 70, (MVI =

Respiratory Rate X Peak Inspiratory Pressure X PaCO2/ 1000) was seen to predict 93%

mortality with 98 % specificity and 67 % sensitivity 15. However a more gentle way of

ventilation with permissive hypercapnia has been shown to be very effective, ensuring

survival with minimal pulmonary morbidity 16.

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Surgical correction is mandatory, though the major determinants of the final outcome

would be prenatal factors that affect the development of pulmonary parenchyma,

pulmonary vascular bed and surfactant system15.

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 EMPHSEMA:

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

anytime within the neonatal period 17. 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 of lobectomy

should be undertaken without delay.

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. Other rare developmental anomalies like cystic adenomatoid malformation of the

lung, congenital pulmonary lymphangectasia etc. could present as neonatal respiratory

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distress, warranting surgical intervention . The outcome of these conditions depends on

the extent of lung involvement and association of other congenital anomalies.

Conclusion

Respiratory distress could be a clinical presentation of both pulmonary and non-

pulmonary causes. While HMD and congenital pneumonia would be the first differential

diagnosis in a preterm infant presenting with these features, pneumonia and meconium

aspiration syndrome form a bulk of the respiratory problems in term infants. Its

imperative that surgical causes like TEF and CDH be detected early, to optimize the

effect of surgical intervention. It must be recognized that the entity of PPHN could

complicate all pulmonary conditions presenting during the early first week of life. Early

detection and appropriate management is essential to ensure better outcome in all infants

presenting with respiratory distress. A systematic approach would useful to confirm the

diagnosis and cause for the respiratory distress. (table 3).

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References

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Edn. Editor & Publisher by Elizabeth John, 2000; pp 75 – 93.

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following maternal steroid treatment in infants born before 30 weeks gestation., J

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6. Whitsett JA, Pryhuber GS, Rice WR, Warner BB, Wert SE, Acute respiratory

disorders, In: Neonatology – Pathophysiology & Management of the newborn

Eds. Avery GB, Fletcher MA, Macdonald MG. 4th edn. JB Lippincott Company,

Philadelphia 1994, 429 – 452.

7. Khatau SP, Ganfwal A, Basu P, Palodhi PKR, The incidence and etiology of

respiratory distress in New born. Indian pediatr 1979; 26.1121-26.

8. Evaldson GR, Malmborg A, Nord CE, Premature rupture of membranes and

ascending infection. Br J Obster Gynecol 1982; 89:793 – 801.

9. Wiswell TE, Bent RC. Meconium staining and meconium aspiration syndrome.

Pediatr clinics North Am1993; 40 : 955 – 981.

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10. Committee on neonatal ventilation/ meconium / chest compressions: Guidelines

proposed at 1992 National Conference on Cardiopulmonary Resuscitation and

Emergency cardiac care, Dallas, 1992. JAMA 1992; 268:2276.

11. Wiswell ET, Gannon CM, Jacob J, Goldsmith L, Edgardo S, Weiss K, Schutzman

D, et al. Delivery room management of apparently vigorous meconium stained

neonate: Results of the multicenter, international collaborative trial. Pediatr

2000;105:1-7.

12. Greenough A, Morley CJ, Roberton NRC. Acute respiratory Diseases in the

newborn. In Textbook of Neonatology Ed. Roberton NRC 2nd Edn Churchill

Livingstone London 1992; 385 - 504

13. Spitzer AR, Davis J, Clarke WT, Bernbaum J, Fox WW. Pulmonary hypertension

and persistent fetal circulation in the newborn. Clinics in Perinatol 1988; 15: 391

– 413.

14. Dave S, Bajpai M, Gupta DK, Agarwala S, Bhatnagar V, Mitra DK. Esophageal

atresia and tracheo-esophageal fistula : A review. Indian J Pediatr 1999; 66: 759 –

772.

15. Bohn DJ, Pearl Are, Irish MS, Glick PL, Postanatal Management of Congenital

diaphragmatic Hernia. Clinics in Perinatol 1996; 23: 843 – 872.

16. Boloker J, Bateman DA, Wung JT, Stolar CJH. Congenital Diaphragmatic Hernia

in 120 infants treated consecutively with permissive hypercapnia / spontaneous

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Textbook of Neonatology Ed. Roberton NRC 2nd Edn Churchill Livingstone London 1992; 529 – 546

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(Table 1) RESPIRATORY DISTRESS IN NEWBORN(adapted with permission from Neonatal Handbook by Elizabeth John 4)

Respiratory Distress in Newborn

At birth or soon after birth Hours to days later

Term Preterm Term and Preterm

MAS HMD PPHN PPHN Immature Lung Obstructed airways

Asphyxia Laryngo tracheomalacia Congenital Pneumonia Pneumonia & Sepsis

Transient Tachypnea of the newborn Cardiac Failure Diaphragmatic hernia Diaphragmatic hernia

Choanal Atresia Pulmonary Hemorrhage Aspiration of other matter

(eg. Blood or mucus)Pulmonary Hypoplasia Skeletal Anomalies

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Table 2. Classification Based on PathophysiologyPulmonary Vasoconstriction

Perinatal Asphyxia / Hypoxia

Pulmonary Parenchymal Disease

Premature in – utero ductal closure

Decreased Pulmonary Vascular BedCongenital Pulmonary Hypoplasia

Secondary pulmonary hypoplasia eg. Diaphragmatic hernia, Oligohydramnios

Increased Pulmonary blood flow associated with congenital heart disease

Decreased pulmonary blood flow as in Hyperviscosity syndrome

Pulmonary Venous hypertension associated with pulmonary venous obstruction, LVF etc. (with permission from Elizabeth John- Neonatal Handbook 4)

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Table 3: Approach to Evaluation

ANTENATAL Polyhydramnios or oligohydramnio, Cervical incompetenceMaternal Illness: Diabetes, PIH, Infections, Maternal medications, antenatal SteroidsAntenatal Ultrasound suggestive of anomalyHistory of Sibling death / similar clinical presentation in sibling.

DELIVERY Prolonged / Premature rupture of membranesMSAF, Asphyxia

CLINICAL Term or PretermTime of presentation and progression of Respiratory DistressExternal congenital anomalies, shape of the chestTachypnea, Grunt, Cyanosis, Acces. Muscles of Respiration, excessive oral secretions, Hyperinflation of chest,Position of cardiac apex, Breath sounds, TransilluminationNormal passage of nasogastric tubeClinical monitoring by Downe’s score ;

INVESTIGATION Pulseoximetry : SaO2, Fluctuations of SaO2, Differential SaO2Chest – Xray (with gastric tube in place)Arterial Blood gas.Echocardiography & CT scan if required.

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