Just another bronchiolitis?

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A 7 week old term female infant presents in winter with wheezing, coughing, and two episodes of non-bilious emesis. She was seen by her pediatrician, who suspected that she had bronchiolitis, and she was treated with oral albuterol syrup. An RSV (Respiratory Syncytial Virus) nasal prep was done, and this was negative; however, the patient’s condition worsened, and she was brought to the Emergency Department later that evening.

 

Exam findings

T37.2R, P168, R70, BP126/86, oxygen saturation 96% on room air.

The infant was fussy, though consolable, with moderate respiratory distress. She was non-toxic in appearance.

The anterior fontanelle was soft and flat. The pupils were equal and reactive and the mucus membranes were moist. The neck was supple. The lungs had diffuse wheezes and crackles bilaterally with intercostal retractions. Heart sounds were difficult to auscultate due to the noisy breathing, but no obvious loud pathologic murmur was heard.

The abdomen was soft and non-tender with active bowel sounds. The liver edge was palpated 3-4 cm below the right costal margin. Capillary refill time in the extremities was 3 seconds.

The patient was placed on supplemental oxygen and a CXR was obtained.

cxr

The CXR showed cardiomegaly and possibly increased pulmonary vascular markings consistent with congestive heart failure (CHF).

The femoral pulses were difficult to palpate. Measurement of blood pressures in the four extremities showed 126/86 (left arm), 132/92 (right arm), 69/41 (left leg), and 63/59 (right leg).

An EKG was done.

ecg

It is not easy to see the tracing of some of the precordial leads because they are very large.

R2 (R wave of V2) extends into the tracing of V1. R4 is off the scale. Suffice it to say that all the R and S waves in V1-V6 are large.

The axis of QRS is 90 degrees (roughly isoelectric in I and positive in AVF). This is a rightward axis. The large QRS’s in V1-V6 meet voltage criteria for both LVH and RVH. This EKG shows biventricular hypertrophy.

 

 

Progress:

The patient was treated with furosemide, 1 mg/kg IV, and dobutamine 5 mcg/kg/min as a continuous infusion, with marked improvement in respiratory status. The infant was admitted to the Pediatric Intensive Care Unit, and a cardiology consultation was obtained.

An echocardiogram showed severe coarctation of the aorta, with a tight posterior shelf distal to the left subclavian artery. The left ventricle was dilated with markedly decreased function. The patient subsequently underwent operative repair of the coarctation, with an uneventful postoperative course.

 

Teaching Points:

  • Wheezing and respiratory distress are a common presentation of CHF in infants. Tachypnea alone may be the earliest sign. Even in the midst of the busy winter bronchiolitis season, the clinician must be careful to consider that the infant with wheezing and tachypnea may be a presentation of CHF, rather than bronchiolitis. Physical exam findings of hepatomegaly or a gallop rhythm may aid in making the proper diagnosis. Parents may also give a history of poor feeding, slow weight gain, and increased sweating. A CXR showing cardiomegaly and increased pulmonary vascular markings will help to confirm the diagnosis.
  • Coarctation of the aorta may present at an early age, as in this case, with progressive CHF. More than 80% of infants with preductal COA develop CHF by 3 months of age. Coarctation of the aorta may also present in the first one or two weeks of life with a sudden state of shock with CHF and cardiovascular collapse when the ductus arteriosus closes (duct-dependent lesion). This is also the typical presentation of the hypoplastic left heart syndrome. Other types of congenital heart disease which may present early in infancy with CHF include large ventricular septal defects, a large patent ductus arteriosus, anomalous left coronary artery, and critical aortic or pulmonary stenosis. Acquired causes of CHF in young infants include viral myocarditis and supraventricular tachycardia.
  • COA can range in severity from very slight with minimal physiologic consequence to severe aortic coarctation or hypoplasia. More severe COA tends to present in infancy while less severe COA may present in later childhood or adolescence. The CXR of the young infant presenting with severe COA typically demonstrates cardiomegaly and increased pulmonary vascular markings (CHF). This is in contrast to the CXR of COA presenting later in childhood, which typically shows a normal or only slightly enlarged heart, and normal pulmonary vascular markings. Rib notching, although pathognomonic for COA, is rarely seen in children younger than 9 years of age. The aorta may develop dilation pre and post coarctation resembling a “3” (3 sign) when viewing the right side of the aorta on an overpenetrated film. If a barium swallow is performed the pre and post coarctation dilation of the aorta impinges upon the esophagus to it giving an “E” appearance to this area of the esophagus (E sign). These signs are not generally seen on routine views that would be ordered in the ED.
  • Treatment of CHF in infancy requires attention to the cardinal ABCs of emergency medicine (Airway, Breathing, Circulation). Administration of supplemental oxygen should be considered as a first-line therapy. If the patient is unstable, intubation with positive-pressure ventilation may be required. To improve cardiac contractility, inotropes such as digoxin or dobutamine may be needed. Dobutamine also has the advantage of decreasing afterload. Diuretics such as furosemide aid by decreasing preload. In severe cases, other vasoactive or inotropic agents such as sodium nitroprusside and amrinone may be considered. These agents should be used in the intensive care unit, using invasive hemodynamic monitoring. If a duct-dependent lesion is suspected, prostaglandin E1 should be started as a continuous infusion at 0.1 mcg/kg/min.

 

References:

1. Li MM, Klassen TP, and Watters LK. Cardiovascular Disorders. In Barkin RM ed. Pediatric Emergency Medicine Concepts and Clinical Practice. St. Louis, Mosby-Year Book Inc., 1992, pp. 576-586.

2. Park MK. The Pediatric Cardiology Handbook. St. Louis, Mosby-Year Book Inc., 1991, pp. 83-86 and 177-182.

3. Rosenthal BW. Wheezing. In Fleisher GR, Ludwig S, eds. Textbook of Pediatric Emergency Medicine, Third Edition. Baltimore, Williams and Wilkins, 1993, pp. 518-525.

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About 

Prof Loren Yamamoto MD MPH MBA. Professor of pediatrics at the University of Hawaii and a practising pediatric emergency doctor in Honolulu. | Contact | View Loren’s DFTB posts

Author: Loren Yamamoto

Prof Loren Yamamoto MD MPH MBA. Professor of pediatrics at the University of Hawaii and a practising pediatric emergency doctor in Honolulu. | Contact | View Loren’s DFTB posts