A 6-month-old boy is brought to the emergency department by his mother during the winter due to 3 days of nasal discharge and cough. His mother states, "He hasn't been breastfeeding well today because he's so congested." The infant has been voiding adequately and has had no vomiting, diarrhea, or skin rash. His older brother attends preschool and is recovering from an upper respiratory illness. The patient has no prior illnesses and no known allergies, and all vaccinations are up to date. He was born at term via an uncomplicated delivery and has met all developmental milestones appropriately. Temperature is 37.5 C (99.5 F), blood pressure is 90/60 mm Hg, pulse is 150/min, and respirations are 50/min. Pulse oximetry shows an oxygen saturation of 93% on room air. Examination reveals moderate respiratory distress with subcostal retractions, coarse breath sounds, and expiratory wheezing bilaterally. Oral mucous membranes are dry, but capillary refill is

Question

A 6-month-old boy is brought to the emergency department by his mother during the winter due to 3 days of nasal discharge and cough.  His mother states, "He hasn't been breastfeeding well today because he's so congested."  The infant has been voiding adequately and has had no vomiting, diarrhea, or skin rash.  His older brother attends preschool and is recovering from an upper respiratory illness.  The patient has no prior illnesses and no known allergies, and all vaccinations are up to date.  He was born at term via an uncomplicated delivery and has met all developmental milestones appropriately.  Temperature is 37.5 C (99.5 F), blood pressure is 90/60 mm Hg, pulse is 150/min, and respirations are 50/min.  Pulse oximetry shows an oxygen saturation of 93% on room air.  Examination reveals moderate respiratory distress with subcostal retractions, coarse breath sounds, and expiratory wheezing bilaterally.  Oral mucous membranes are dry, but capillary refill is <2 seconds.  The patient is admitted to the hospital and placed on appropriate infection-control precautions. Which of the following is the most appropriate method of diagnosing this patient's condition?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c078_b7fb_8f63_bb36aaff53bd_MD0005_00 Bronchiolitis is generally diagnosed clinically. Classic features include an upper respiratory prodrome of rhinorrhea, nasal congestion, and cough, followed 2-3 days later by lower airway signs of wheezing and increased work of breathing. Antigen testing of nasal or pulmonary secretions (Choice A) or nucleic acid amplification testing is used to detect breakthrough respiratory syncytial virus (RSV) infection among infants who receive palivizumab prophylaxis. In such patients, RSV infection provides active immunity and protection, and the palivizumab can be discontinued. (Choice B) Because bronchiolitis is a viral infection, blood cultures are not indicated, particularly due to the low rate of false-positive cultures for contaminant bacteria. In general, laboratory tests, including complete blood count and chemistry, are unnecessary in patients with bronchiolitis. (Choice C) Chest x-ray often reveals atelectasis and results in overdiagnosis of pneumonia and unnecessary antibiotic therapy. Complete blood count and chemistry are also unnecessary. (Choice E) Serology is generally not helpful in acute illness as it can take weeks for antibody titers to rise. Serology is also unreliable in infants age <6 months due to passively acquired maternal antibodies. Educational objective: The diagnosis of bronchiolitis is primarily clinical, and routine testing for respiratory syncytial virus (RSV) is unnecessary. If a decision is made to obtain viral testing, RSV antigens can be quickly detected in nasal or pulmonary secretions. References: Clinical practice guideline: the diagnosis, management, and prevention of bronchiolitis. (http://www.ncbi.nlm.nih.gov/pubmed/25349312) Prospective multicenter study of viral etiology and hospital length of stay in children with severe bronchiolitis. (http://www.ncbi.nlm.nih.gov/pubmed/22473882)

A 6-Month-Old Boy Is Brought to the Emergency Department by His