Wheezing - Case 1-3: 5-Week-Old Boy
Wheezing - Case 1-3: 5-Week-Old Boy: Excerpt from Pediatric Complaints and Diagnostic Dilemmas
I. History of Present Illness
A 5-week-old boy presented to the emergency department with a 1-day history of
fever and
“wheezing.” His visit to the hospital was prompted by a rectal temperature of 38.6°C. His respiratory difficulty seemed worse with feeding. There had been no
emesis, diarrhea, rhinorrhea, cough, or cyanosis. He had been drinking
approximately 4 ounces of a cow
's milk-based formula every 3 hours. His only ill contact was his mother, who had
had cough and rhinorrhea for 1 week.
II. Past Medical History
He was born by spontaneous vaginal delivery at 39 weeks gestation. His birth
weight was 3,900 g. The pregnancy, labor, and delivery were uncomplicated.
Prenatal ultrasound revealed polyhydramnios but was otherwise normal. The
mother
's prenatal laboratory studies included a negative group B Streptococcus screen. Testing for antibodies to human immunodeficiency virus (HIV) had not
been performed. The infant had not previously been hospitalized.
III. Physical Examination
T, 38.5°C; HR, 180 bpm; RR, 70/min.; BP, 62/40 mm Hg; SpO2, 96% in room air
Length, 25th percentile; weight, 50th percentile
The infant was ill-appearing and in moderate respiratory distress. His anterior
fontanelle was open and flat. There was no conjunctival injection or discharge.
There was intermittent grunting and nasal flaring. Moderate intercostal and
subcostal retractions were present. Breath sounds were diminished throughout
the left chest. The right lung was clear to auscultation. There was no
wheezing. The heart sounds were normal. The liver was palpable 1 cm below the
right costal margin. The spleen was not palpable. The Moro reflex, grasp, tone,
and reflexes were normal. There were no rashes or petechiae.
IV. Diagnostic Studies
Arterial blood gas revealed the following: pH, 7.40; carbon dioxide tension
(PaCO
2), 40 mm Hg; oxygen tension (PaO2), 214 mm Hg; and bicarbonate, 26 mEq/L. The complete blood count demonstrated
37,900 WBCs/mm
3, including 3% band forms, 67% segmented neutrophils, and 30% lymphocytes. The
platelet count was 520,000/mm
3, and hemoglobin was 9.4 g/dL. Serum electrolytes, blood urea nitrogen, and
creatinine were normal. There were no WBCs, protein, or nitrites on
urinanalysis. A blood culture was obtained. Lumbar puncture was not performed
due to the patient
's respiratory distress. Chest radiography demonstrated left lower lobe
consolidation with an associated pleural effusion causing rightward shift of
the mediastinal structures (Fig. 1-4).
V. Course of Illness
The patient was diagnosed with bacterial pneumonia and treated with vancomycin
and cefotaxime. The blood culture was subsequently negative. A CT scan of the
chest, performed to better delineate the pulmonary findings, suggested an
alternative diagnosis (Fig. 1-5).
Discussion: Case 1-3
I. Differential Diagnosis
In this 5-week-old boy with respiratory distress and lobar consolidation, the
most likely diagnosis is bacterial pneumonia with pleural empyema. Etiologic
organisms in this age group include group B
Streptococcus, Listeria monocytogenes, and gram-negative enteric bacilli. The radiographic appearance of the lung may
suggest a congenital lung malformation such as pulmonary sequestration,
bronchogenic cyst, or cystic adenomatoid malformation. Infantile lobar
emphysema is unlikely because the lung, despite causing a mediastinal shift,
does not appear to be overinflated. Other congenital considerations include
enterogenic cysts and CDH. Acquired causes include mediastinal neoplasm (e.g.,
neuroblastoma) and chronic pulmonary infection distal to an aspirated foreign
body or an area of bronchiectasis. Chronic pulmonary infection may result in
neovascularization of the infected tissue by ingrowth of systemic arteries.
Such acquired systemic vascularization typically consists of several small
arteries rather than one or two large arteries that typically supply a
pulmonary sequestration. It may be impossible to make the distinction between
true pulmonary sequestration and so-called pseudosequestration secondary to
chronic infection preoperatively.
II. Diagnosis
CT of the chest (Fig. 1-5) revealed a large (6 cm × 5 cm × 8 cm), heterogeneously enhancing mass with disorganized vasculature in the
posterior aspect of the left hemithorax. These findings were most consistent
with an
extralobar pulmonary sequestration.
III. Incidence and Anatomy
The term pulmonary sequestration refers to a congenital malformation consisting of abnormally developed pulmonary
parenchyma that is separate from the normal lung. The tissue is nonfunctioning,
does not communicate with the tracheobronchial tree, and derives its blood
supply from the aorta. There may be a single large anomalous artery, but
occasionally multiple small anomalous arteries from above or below the
diaphragm supply the sequestered lobe. The venous drainage may be pulmonary or
systemic (inferior vena cava, azygous vein, or portal vein). Drainage into
systemic veins produces a left-to-right shunt. In this case, the vessels
appeared to drain into the azygous and hemiazygous veins.
The overall incidence of pulmonary sequestration is not well defined, but
sequestrations have been found in 1% to 2% of all resected pulmonary specimens.
Pulmonary sequestration occurs when an accessory lung bud originates during
embryonic development. If the bud originates early, the sequestration is
considered intralobar, because the normal and sequestered lung share a common
pleural covering. If the bud originates later, the sequestration is considered
extralobar, because the sequestered lung has its own pleura. About 75% of
reported cases of pulmonary sequestration are intralobar; 1% have both an
intralobar and an extralobar component.
Associated malformations occur in 60% of extralobar sequestrations and 10% of
intralobar sequestrations. The most common associated malformations are
duplications of the colon or terminal ileum, esophageal cysts or
communications, vertebral or rib anomalies, diaphragmatic hernia, and
congenital heart disease. Pulmonary sequestration is left-sided in 90% of cases
and bilateral in fewer than 0.5% of cases. Approximately two thirds of all
cases involve the left lower lobe.
IV. Clinical Presentation
Most children with extralobar pulmonary sequestration present during the first
year of life. They may be discovered during the neonatal period while
undergoing evaluation of other congenital anomalies. In such cases, the
associated congenital anomalies usually dominate the clinical picture. A few
children with extralobar sequestration present with respiratory distress when
the sequestered lobe impairs ventilation by impinging on the surrounding lung.
Cases not diagnosed in the neonatal period may be detected incidentally on
chest radiographs obtained during a respiratory illness. Infection of an
extralobar sequestration is uncommon.
Intralobar pulmonary sequestration is rarely detected during infancy; two thirds
of patients present after 10 years of age. Common symptoms include productive
cough, hemoptysis, recurrent pneumonia, fever, and chest pain. A few patients
with large supplying arteries have worsening exercise tolerance or congestive
heart failure due to a large systemic arterial-to-pulmonary venous shunt
through the sequestration. Infection of the sequestration, usually due to a
fistula between the sequestration and the respiratory or digestive tract,
occurs more commonly with intralobar than with extralobar sequestrations.
Physical examination reveals dullness to percussion and decreased breath sounds
in the area of the sequestration. Digital clubbing and cyanosis may be present.
Skeletal abnormalities such as pectus excavatum, thoracic asymmetry, and rib
anomalies are noted in some patients. Rarely, an intrathoracic bruit is heard
in the region of the sequestration.
V. Diagnostic Approach
Prenatal ultrasound. Pulmonary sequestration may be diagnosed during routine obstetric screening or
during investigation of polyhydramnios, which is reported in many cases.
Chest roentgenogram. It is difficult to distinguish between intralobar and extralobar sequestrations
by chest roentgenogram alone. Both are typically found in the posteromedial
aspect of the lower lobe, and calcifications are occasionally present.
Intralobar sequestrations more often appear cyst-like. Air-fluid levels
indicate a pulmonary communication. Extralobar sequestrations appear as a solid
mass.
Chest computed tomography. CT allows differentiation of pulmonary sequestration from other lung
abnormalities.
Angiography. Angiography of the thoracic and abdominal aorta will demonstrate both the
systemic arterial blood supply and the venous drainage.
Nuclear scintigraphy. After intravenous injection, peak radioisotope activity occurs earlier in lung
tissue with normal pulmonary blood supply than in the sequestration with
systemic blood supply. Nuclear scintigraphy has been proposed as an alternative
to traditional angiography.
Other studies. Magnetic resonance angiography (MRA) is a less invasive study that may
eventually replace traditional angiography in the evaluation of pulmonary
sequestration. An upper gastrointestinal barium study should be considered to
exclude the possibility of a communication with the gastrointestinal tract.
VI. Treatment
Symptomatic intralobar and extralobar sequestrations require immediate
resection. Asymptomatic sequestrations also require removal because of the risk
of subsequent serious infection. Extralobar sequestrations, because of their
separate pleural covering, can often be removed without disruption of the
normal lung. Intralobar sequestrations require lobectomy for removal because of
the inability to separate the sequestration from the normal lung. In cases of
acute infection, preoperative antibiotic coverage should be directed against
common respiratory pathogens,
Staphylococcus aureus, and anaerobes. Ampicillin-sulbactam or the combination of clindamycin and
cefotaxime are appropriate empiric antibiotic choices. The resected tissue
should be sent for aerobic and anaerobic bacterial cultures, mycobacterial
cultures, and fungal cultures.
Intraoperative mortality is highest in those with associated congenital
anomalies. Intraoperative complications are usually caused by severance of a
systemic artery. Postoperative complications include emphysema, hemothorax, and
bronchopleural fistulas; the incidence of each is approximately 1%. The
long-term prognosis in those patients without other debilitating congenital
anomalies is excellent.
In this case, MRA was performed and the extralobar sequestration was removed
without complications on the following day. Cultures of the resected
sequestration were sterile. The patient recovered uneventfully.
VII. References
1. Carter R. Pulmonary sequestration. Ann Thorac Surg 1969;7:68–88.
2. Collin PP, Desjardins JG. Pulmonary sequestration. J Pediatr Surg 1987;22:750–753.
3. Kravitz RM. Congenital malformation of the lung. Pediatr Clin North Am 1994;41:453–472.
4. Lierl M. Congenital abnormalities. In: Hilman BC, ed. Pediatric respiratory disease: diagnosis and treatment. Philadelphia: WB Saunders, 1993:457–498.
5. Oliphant L, McFadden RG, Carr TJ, et al. Magnetic resonance imaging to
diagnose intralobar pulmonary sequestration.
Chest 1987;91:500–502.
6. Savic B, Birtel FJ, Tholen W, et al. Lung sequestration: report of seven
cases and review of 540 published cases.
Thorax 1979;34:96–101.
7. Stocker JT, Kagan-Hallet K. Extralobar pulmonary sequestration: analysis of
15 cases.
Am J Clin Pathol 1979;72:917–925.
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.
More About SCID
More Medical Textbooks Online about SCID
Review other book chapters online related to SCID:
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
» Next page: Wheezing - Case 1-5: 5-Week-Old Boy (Pediatric Complaints and Diagnostic Dilemmas)
Rate This Website
What do you think about the features of this website?
Take our user survey and have your say:
Website User Survey
Medical Tools & Articles:
Next articles:
Tools & Services:
Medical Articles:
Forums & Message Boards
- Ask or answer a question at the Boards:
