Полезные материалы за все 6 курсов / Учебники, методички, pdf / Kaplan Pediatrics USMLE 2CK 2021

Chapter 7 λ Child Abuse and Neglect

Learning Objectives

Demonstrate understanding of upper airway obstruction from foreign bodies, congenital anomalies, and acute inflammatory upper airway obstruction

Answer questions about inflammatory and infectious disorders of the small airwaysDescribe the epidemiology and treatment of cystic fibrosis

Recognize risk factors and presentation of sudden infant death syndrome

ACUTE INFLAMMATORY UPPER AIRWAY OBSTRUCTION

Croup

A 12-month-old child is brought to your office because of a barky cough. The mother states that over the past 3 days the child has developed a runny nose, fever, and cough. The symptoms are getting worse, and the child seems to have difficulty breathing. He sounds like a seal when he coughs.

•Infective agents—parainfluenza types 1, 2, 3

•Age 3 months–5 years; most common in winter; recurrences decrease with increasing growth of airway

•Inflammation of subglottis

•Signs and symptoms/examination—upper respiratory infection 1–3 days, then barking cough, hoarseness, inspiratory stridor; worse at night, gradual resolution over 1 week

•Complications—hypoxia only when obstruction is complete

•Diagnosis—clinical, x-ray not needed (steeple sign if an x-ray is performed)

•Treatment is supportive plus:

–Mild: corticosteroid then observe; if improved, then home but if worsens, treat as moderate croup

–Moderate: nebulized epinephrine + corticosteroid, then observe; if improved, then home but if worsens, repeat epinephrine and admit to hospital

–Severe: nebulized epinephrine and corticosteroid then admit to hospital (possibly PICU)

USMLE Step 2 CK λ Pediatrics

68

Chapter 8 λ Respiratory Disease

Table 8-1. Croup and Epiglottitis

Clinical Recall

A 5-year-old boy has had a low-grade fever, runny nose, non-productive cough, and mild stridor for 2 days. He sounds like a seal when he coughs. He is non-toxic appearing and has no increased work of breathing. What is the next step?

A.Chest x-ray to evaluate for the steeple sign

B.Discharge with close follow-up if symptoms worsen

C.Nebulized epinephrine

D.Laryngoscopy

E.Parenteral steroids

Answer: B

USMLE Step 2 CK λ Pediatrics

CONGENITAL ANOMALIES OF THE LARYNX

Table 8-2. Anomalies of the Larynx

70

Chapter 8 λ Respiratory Disease

INFLAMMATORY DISORDERS OF THE SMALL AIRWAYS

Bronchiolitis

A 6-month-old infant presents to the physician with a 3-day history of upper respiratory tract infection, wheezy cough, and dyspnea. On physical examination, the patient has a temperature of 39 C (102 F), respirations of 60 breaths/min, nasal flaring, and accessory muscle usage. The patient appears to be air hungry, and the oxygen saturation is 92%.

•Infective agents—respiratory syncytial virus (RSV) (50%), parainfluenza, adenovirus, other viruses

•Typical age—almost all children infected by age <2 years, most severe at age 1–2 months in winter months.

•Inflammation of the small airways (inflammatory obstruction: edema, mucus, and cellular debris) → (bilateral) obstruction → air-trapping and overinflation

•Clinical presentation

–Signs and symptoms:

°Mild URI (often from household contact), decreased appetite and fever, irritability, paroxysmal wheezy cough, dyspnea, and tachypnea

°Apnea may be more prominent early in young infants.

–Examination:

°Wheezing, increased work of breathing, fine crackles, prolonged expiratory phase

°Lasts average of 12 days (worse in first 2–3 days)

•Complications—bacterial superinfection, respiratory insufficiency and failure (worse in infants with small airways and decreased lung function)

•Diagnosis and Treatment (per AAP Clinical Practice Guidelines, based on research and clinical evidence)

–Diagnosis is clinical. Radiography (nonspecific, viral) and lab studies (microbiology) should not be routinely used.

–Treatment is primarily supportive; hospitalize per severity assessment based on history and physical. Should not administer nebulized albuterol, nebulized epinephrine, nebulized hypertonic saline or systemic (or nebulized) corticosteroids as there is lack of evidence for any of these anecdotal therapies.

•Prevention—monoclonal antibody to RSV F protein (preferred: palivizumab) in high-risk patients only (otherwise healthy infants with a gestational age of 29 weeks, 0 days or greater and during the first year of life to infants with hemodynamically significant heart disease or chronic lung disease of prematurity defined as preterm infants <32 weeks 0 days’ gestation who require >21% oxygen for at least the first 28 days of life)

Chapter 8 λ Respiratory Disease

–Bacterial pneumonia:

°Sudden shaking chills with high fever, acute onset

°Significant cough and chest pain

°Tachypnea; productive cough

°Splinting on affected side—minimize pleuritic pain

°Examination—diminished breath sounds, localized crackles, rhonchi early; with increasing consolidation, markedly diminished breath sounds and dullness to percussion

–Chlamydia trachomatis pneumonia:

°No fever or wheezing (serves to distinguish from RSV)

°1–3 months of age, with insidious onset

°May or may not have conjunctivitis at birth

°Mild interstitial chest x-ray findings

°Staccato cough

°Peripheral eosinophilia

–Chlamydophila pneumoniae and mycoplasma pneumoniae

°Cannot clinically distinguish

°Atypical, insidious pneumonia; constitutional symptoms

°Bronchopneumonia; gradual onset of constitutional symptoms with persistence of cough and hoarseness; coryza is unusual (usually viral)

°Cough worsens with dyspnea over 2 weeks, then gradual improvement over next 2 weeks; becomes more productive; rales are most consistent finding (basilar)

•Diagnosis

–Chest x-ray confirms diagnosis:

°Viral—hyperinflation with bilateral interstitial infiltrates and peribronchial cuffing

°Pneumococcal—confluent lobar consolidation

°Mycoplasma—unilateral or bilateral lower-lobe interstitial pneumonia; looks worse than presentation

°Chlamydia—interstitial pneumonia or lobar; as with Mycoplasma, chest x-ray often looks worse than presentation

–White blood cells:

°Viral—usually <20,000/mm3 with lymphocyte predominance

°Bacterial—usually 15,000–40,000/mm3 with mostly granulocytes

°Chlamydia—eosinophilia

–Definitive diagnosis:

°Viral—isolation of virus or detection of antigens in respiratory tract secretions; (usually requires 5–10 days); rapid reagents available for RSV, parainfluenza, influenza, and adenovirus

°Bacterial—isolation of organism from blood (positive in only 10–30% of children with S. pneumoniae), pleural fluid, or lung; sputum cultures are of no value in children. For mycoplasma get PCR (had been IgM titers). PCR is also becoming the test of choice for viruses.