Tachypnoea in a Well Baby: What to Do Next?
Clinical examination is important, with some red flag warning signs (Box 2). The child's colour is important (cyanosis, paleness). In addition to the respiratory rate, other signs of respiratory distress must be looked for, including intercostal and subcostal recession, and tracheal tug, use of accessory muscles, grunting, and nasal flaring. Some well babies with tachypnoea have a degree of recession as the only other clinical sign. Obviously the presence of crackles, wheeze and stridor is important for the diagnosis. Paradoxical breathing, an inward movement of the chest wall during inspiration, often with a seesaw thoracoabdominal motion, must be looked for (neuromuscular disease, diaphragmatic abnormality, upper airway obstruction). The shape of the thorax is checked to ensure normal dimensions (eg, very small in asphyxiating thoracic dystrophy, bell-shaped in pulmonary hypoplasia). The presence of persistent rhinitis should make one consider primary ciliary dyskinesia.
Examination focused specifically on the cardiovascular system is also important and often neglected. Central cyanosis is most evident in the mouth, and the cardiac apex may be visibly displaced if there is cardiomegaly. Precordial palpation may reveal a right-sided impulse in Scimitar syndrome, or complex forms of congenital heart disease associated with atrial isomerism (visceral heterotaxy or a mirror image arrangement in primary ciliary dyskinesia). A prominent precordial impulse is an important sign of cardiovascular disease with pressure or volume overload of the heart. Femoral pulses which are weak or difficult to feel (coarctation of the aorta), or generally weak pulses (myocarditis, dilated cardiomyopathy, severe aortic stenosis or other forms of left heart obstruction) can be important signs. Liver enlargement is usually a manifestation of heart failure, but can be palpable if it is displaced by overinflated lungs. Unusually soft or loud heart sounds, ejection clicks, wide splitting of the second heart sound, a loud P2 or a heart murmur may indicate a cardiovascular cause. However, particularly in the newborn, heart murmurs are very common, while significant congenital heart disease during infancy is often not accompanied by a heart murmur. Always listen over the skull and particularly the occiput for the murmur of a cerebral arteriovenous fistula, whose only clinical manifestation might be tachypnoea. Thus whenever tachypnoea has a cardiovascular cause, even without a heart murmur there is usually a clinical pointer to a cardiac anomaly.
The child's weight, height and head circumference will give an indication of faltering growth which may be secondary to tachypnoea or an underlying condition. Abdominal examination is done to exclude an enlarged liver or spleen, or an abdominal mass. A basic neurological examination is done, particularly for hypotonia which may indicate a neuromuscular disorder. The patency of the nose must be examined to exclude choanal stenosis or unilateral atresia (it may be necessary to pass a nasogastric tube down both sides).
Is the Examination Normal?
Clinical examination is important, with some red flag warning signs (Box 2). The child's colour is important (cyanosis, paleness). In addition to the respiratory rate, other signs of respiratory distress must be looked for, including intercostal and subcostal recession, and tracheal tug, use of accessory muscles, grunting, and nasal flaring. Some well babies with tachypnoea have a degree of recession as the only other clinical sign. Obviously the presence of crackles, wheeze and stridor is important for the diagnosis. Paradoxical breathing, an inward movement of the chest wall during inspiration, often with a seesaw thoracoabdominal motion, must be looked for (neuromuscular disease, diaphragmatic abnormality, upper airway obstruction). The shape of the thorax is checked to ensure normal dimensions (eg, very small in asphyxiating thoracic dystrophy, bell-shaped in pulmonary hypoplasia). The presence of persistent rhinitis should make one consider primary ciliary dyskinesia.
Examination focused specifically on the cardiovascular system is also important and often neglected. Central cyanosis is most evident in the mouth, and the cardiac apex may be visibly displaced if there is cardiomegaly. Precordial palpation may reveal a right-sided impulse in Scimitar syndrome, or complex forms of congenital heart disease associated with atrial isomerism (visceral heterotaxy or a mirror image arrangement in primary ciliary dyskinesia). A prominent precordial impulse is an important sign of cardiovascular disease with pressure or volume overload of the heart. Femoral pulses which are weak or difficult to feel (coarctation of the aorta), or generally weak pulses (myocarditis, dilated cardiomyopathy, severe aortic stenosis or other forms of left heart obstruction) can be important signs. Liver enlargement is usually a manifestation of heart failure, but can be palpable if it is displaced by overinflated lungs. Unusually soft or loud heart sounds, ejection clicks, wide splitting of the second heart sound, a loud P2 or a heart murmur may indicate a cardiovascular cause. However, particularly in the newborn, heart murmurs are very common, while significant congenital heart disease during infancy is often not accompanied by a heart murmur. Always listen over the skull and particularly the occiput for the murmur of a cerebral arteriovenous fistula, whose only clinical manifestation might be tachypnoea. Thus whenever tachypnoea has a cardiovascular cause, even without a heart murmur there is usually a clinical pointer to a cardiac anomaly.
The child's weight, height and head circumference will give an indication of faltering growth which may be secondary to tachypnoea or an underlying condition. Abdominal examination is done to exclude an enlarged liver or spleen, or an abdominal mass. A basic neurological examination is done, particularly for hypotonia which may indicate a neuromuscular disorder. The patency of the nose must be examined to exclude choanal stenosis or unilateral atresia (it may be necessary to pass a nasogastric tube down both sides).