Wheezing - Case 1-5: 5-Week-Old Boy
Wheezing - Case 1-5: 5-Week-Old Boy: Excerpt from Pediatric Complaints and Diagnostic Dilemmas
I. History of Present Illness
A 5-week-old Caucasian boy presented to the emergency department with worsening
cough and respiratory difficulty. Two weeks before admission, he was evaluated
by his primary physician for poor weight gain and periodic emesis. His weight
of 3,050 g was the same as his birth weight. He had Hemoccult-positive stool
and was diagnosed with cow
's milk protein allergy. His formula was changed to a protein hydrolysate
formula. One week before admission, his weight had increased to 3,100 g.
However, he began having more frequent episodes of emesis. Three days before
admission he developed a cough, tachypnea, and audible wheezing. He was
evaluated at a nearby hospital, diagnosed with bronchiolitis, and treated with
nebulized albuterol. His tachypnea had not improved despite receiving nebulized
albuterol every 4 hours. His cough had increased in frequency. He was evaluated
in the emergency department for worsening cough and continued tachypnea. The
parents mentioned that the infant had always appeared dusky with crying, but
this color change has occurred more frequently over the past few days. He had
also had numerous episodes of posttussive emesis. Over the past 3 days, he had
taken only 2 ounces of formula every 4 hours. The parents denied ill contacts,
diarrhea, and lethargy. Both parents smoked, but only outside the home. There
were no pets.
II. Past Medical History
He was born at 37 weeks' gestation after an uncomplicated pregnancy. The mother's group B Streptococcus colonization status was not known, so she received two doses of ampicillin
before delivery. The infant
's Apgar scores were 7 and 8 at 1 and 5 minutes, respectively. He had not
previously required hospitalization.
III. Physical Examination
T, 37.7°C; RR, 60/min; BP, 78/37 mm Hg; HR 160 bpm; SpO2, 88% in room air
Weight, 3.0 kg (less than 5th percentile); length, 49 cm (less than 5th
percentile)
Physical examination revealed a cyanotic infant in moderate respiratory
distress. The anterior fontanelle was open and flat. There was no conjunctival
injection. There were no oral mucosal ulcerations. Capillary refill was brisk.
The heart sounds were normal. Femoral pulses were palpable. There were
intercostal retractions. Rales and wheezes were present diffusely. The liver
edge was palpable 3 cm below the right costal margin. The remainder of the
examination was normal.
IV. Diagnostic Studies
Laboratory analysis revealed 10,200 WBCs/mm3, with 76% segmented neutrophils, 19% lymphocytes, and 3% monocytes. The
hemoglobin was 13.0 g/dL, and there were 350,000 platelets/mm
3. Hepatic function panel was as follows: total bilirubin, 0.3 mg/dL; alanine
aminotransferase, 32 U/L; aspartate aminotransferase, 66 U/L. The prothrombin
and partial thromboplastin times and fibrinogen split products were normal.
Blood cultures were obtained. Chest radiography revealed diffuse interstitial
pulmonary edema but a normal cardiothymic silhouette.
V. Course of Illness
The patient was treated with ampicillin and cefotaxime for presumed bacterial
sepsis. He also received nebulized albuterol. His respiratory status
progressively worsened. An arterial blood gas analysis revealed the following:
pH, 7.22; PaCO
2, 65 mm Hg; PaO2, 45 mm Hg. The patient required endotracheal intubation. Electrocardiographic
studies suggested a possible diagnosis (Fig. 1-7).
Discussion: Case 1-5
I. Differential Diagnosis
In an infant with cyanosis and respiratory distress, bacterial or viral sepsis
must be considered. Children with either viral bronchiolitis or pertussis may
present with cyanosis, respiratory symptoms, and rapid deterioration. In this
child, the history of periodic cyanosis with crying since birth provided a clue
to the diagnosis. The differential diagnosis includes a large ventricular
septal defect, patent ductus arteriosus, truncus arteriosus, atrioventricular
canal, single ventricle without pulmonary stenosis, and total anomalous
pulmonary venous connection (TAPVC). Except for TAPVC, these cardiac anomalies
typically produce electrocardiographic evidence of left atrial or left
ventricular hypertrophy. Children with TAPVC have right ventricular
hypertrophy. The severity of illness warranted an echocardiogram, which
provided the definitive diagnosis.
II. Diagnosis
The electrocardiogram (Fig. 1-7) revealed right axis deviation (QRS axis = 135°) and right ventricular hypertrophy. Echocardiography revealed a large and
dilated right ventricle with a moderately hypoplastic left atrium and a patent
foramen ovale. The pulmonary veins merged to form a common vein that drained
into the portal venous system below the diaphragm (Fig. 1-8). No pulmonary
veins entered the left atrium. There were no other cardiac defects.
The echocardiographic findings confirmed the diagnosis of infradiaphragmatic
TAPVC.
III. Incidence and Epidemiology
TAPVC defines an anomaly in which there is no direct connection between the
pulmonary veins and the left atrium. Instead, the pulmonary veins merge to form
a common pulmonary vein that connects either to one of the systemic veins or
directly to the right atrium. The malformation does not compromise fetal
circulation during intrauterine life, because pulmonary arterial resistance is
high and some blood flows to the systemic circulation through the patent
foramen ovale. The combined systemic and pulmonary blood flow to the lungs is
only mildly elevated. After birth, as pulmonary resistance falls, a
progressively larger proportion of the mixed venous blood flows to the lungs,
causing massive pulmonary overcirculation.
Several classification schemes have been proposed based on physiologic or
prognostic implications of the anomalous connections. Generally, the
connections are divided by whether the pulmonary veins merge with the coronary
sinus of the right atrium (cardiac) or with the systemic venous circulation
above the diaphragm (supracardiac) or below it (infradiaphragmatic).
Approximately 75% of the connections are supracardiac, with the left innominate
vein, coronary sinus, and superior vena cava serving as the most common
anatomic sites of connection.
In TAPVC, because all venous blood ultimately returns to the right atrium, a
communication between the right and left sides of the heart is necessary to
sustain life. A patent foramen ovale or an atrial septal defect allows free
communication between the two atria and, therefore, is considered part of the
disorder. Other intracardiac anomalies occur in up to one third of cases and
include common atrioventricular canal, transposition of the great arteries,
tetralogy of Fallot, and hypoplastic left heart syndrome. TAPVC with drainage
directly into the right atrium occurs in patients with visceral heterotaxy and
polysplenia.
The incidence of TAPVC is not clear. TAPVC occurred in 2% of cases in an autopsy
series of 800 children with congenital cardiac disease who died during the
first year of life. TAPVC also occurred in 41 (1.5%) of 2,659 infants with
cardiovascular malformations identified in the Baltimore-Washington Infant
Study. Infradiaphragmatic TAPVC is more prevalent in boys (male:female ratio,
3:1). There is no sex prevalence in TAPVC with other sites of connection.
IV. Clinical Presentation
The clinical presentation of children with TAPVC depends on the presence or
absence of pulmonary venous obstruction. Most children without obstruction
present with tachypnea and failure to thrive, with gradually worsening cyanosis
and congestive heart failure. Approximately 50% have symptoms during the first
month of life, and the remainder during the first year. Cyanosis may be minimal
initially, but it increases as congestive heart failure progresses. Cyanosis
occurs because the pulmonary veins carry oxygenated blood to the systemic
venous circulation instead of to the left atrium. Congestive heart failure
occurs because of increased pulmonary blood flow and pulmonary hypertension.
Hepatomegaly and peripheral edema often accompany cardiac failure. There is no
cardiac murmur.
Obstruction is more common in children with infradiaphragmatic TAPVC because of
venous compression as the common venous trunk passes through either the
esophageal hiatus of the diaphragm or the portal venous circulation. Most
children with infradiaphragmatic TAPVC, and one third of children with
supracardiac TAPVC, present with pulmonary venous obstruction. These infants
are usually asymptomatic at birth but develop symptoms within the first few
weeks of life. Infants with pulmonary venous obstruction present with rapidly
progressive dyspnea, pulmonary edema, cyanosis, and congestive heart failure.
Alteration in the character of the cry (“neonatal dysphonia”) occurs in one fourth of infants with supracardiac TAPVC as a result of
compression of the left recurrent laryngeal nerve as it passes the dilated
common pulmonary vein. Infants with infradiaphragmatic TAPVC may have worsening
cyanosis with swallowing, straining, and crying, as a consequence of
interference with pulmonary venous outflow caused by increased intraabdominal
pressure or impingement of the esophagus on the common pulmonary vein as it
exits through the esophageal hiatus. The child in the presented case did not
have pulmonary venous obstruction despite having infradiaphragmatic TAPVC. His
history of cyanosis with crying is consistent with infradiaphragmatic TAPVC.
V. Diagnostic Approach
The diagnosis should be suspected on the basis of the clinical presentation.
Electrocardiogram. A tall peaked P wave in lead II or in the right precordial leads characterizes
right atrial enlargement, a feature of TAPVC without obstruction. Right atrial
enlargement is not usually present in TAPVC with obstruction, due to fulminant
presentation very early in life. Right ventricular hypertrophy is manifested by
high voltages in the right precordial leads. Right axis deviation is always
present due to right-sided hypertrophy.
Chest roentgenogram. The lung fields reflect increased pulmonary blood flow. The cardiac silhouette
may be normal, or right ventricular hypertrophy may be evident.
Echocardiography. The echocardiogram reveals signs of right ventricular volume overload. The right
atrium is enlarged. The right ventricle is hypertrophied and dilated and
compresses the intraventricular septum. The pulmonary arteries are dilated. The
pulmonary veins are seen to form a common vein behind the heart. The size and
orientation of the venous confluence are important for surgical planning.
Associated intracardiac defects may be identified.
Cardiac catheterization. The accuracy of Doppler echocardiography precludes the routine need for
diagnostic catheterization. Right ventricular pressures are usually equal to
systemic pressures.
VI. Treatment
Complete surgical repair should be performed as early as possible. A large
side-to-side anastomosis is created between the left atrium and the common
pulmonary vein. Occasionally, the distal portion of the common pulmonary vein
is ligated. The foramen ovale or atrial septal defect is closed. A hypoplastic
left atrium may require surgical enlargement.
Residual stenosis at the left atrial-venous anastomosis created at operative
repair develops in 10% of children. This stenosis requires reintervention and
patch plasty. Postoperative pulmonary venous obstruction occurs 1 to 3 months
after repair in 5% of patients. Late atrial arrhythmias develop in a small
number of patients.
VII. References
1. Correa-Villasenor A, Ferencz C, Boughman JA, et al. Total anomalous pulmonary
venous return: familial and environmental factors. The Baltimore-Washington
infant study group.
Teratology 1991;44:415–428.
2. Geva T, Van Praagh S. Anomalies of the pulmonary veins. In: Allen HD,
Gutgesell HP, Clark EB, et al., eds.
Moss and Adams' heart disease in infants, children, and adolescents, including the fetus and
young adult,
6th ed. Philadelphia: Lippincott Williams & Wilkins, 2001:736–772.
3. Hyde JA, Stumper O, Barth MJ, et al. Total anomalous pulmonary venous
connection: outcome of surgical correction and management of recurrent venous
obstruction.
Eur J Cardiothorac Surg 1999;15:735–740.
4. Michielon G, Di Donato RM, Pasquini L, et al. Total anomalous pulmonary
venous connection: long-term appraisal with evolving technical solutions.
Eur J Cardiothoracic Surg 2002;22:184–191.
5. Shankargouda S, Krishnan U, Murali R, et al. Dysphonia: a frequently
encountered symptom in the evaluation of infants with unobstructed supracardiac
total anomalous pulmonary venous connection.
Pediatr Cardiol 2000;21:458–460.
Pictures
Book Source Details
- Book Title: Pediatric Complaints and Diagnostic Dilemmas
- Author(s): Samir S Shah MD; Stephen Ludwig MD
- Year of Publication: 2003
- Copyright Details: Pediatric Complaints and Diagnostic Dilemmas, Copyright © 2003 Lippincott Williams & Wilkins.
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