2025 – PAGE 429 – 430 – PULMONOLOGY

2025 – Core Study Guide 26 – Pulmonology 2025 – PAGE 429 – 430 – PULMONOLOGY

PERSISTENT PULMONARY HYPERTENSION

Elevated blood pressure (hypertension) of the pulmonary artery causes decreased blood flow to the lungs in cases of persistent pulmonary hypertension. This can be diagnosed at birth with imaging showing unusually clear fields. Do an echocardiogram to look for elevated pulmonary artery pressures. If the child is in distress, do a “hyperoxia test” to see if oxygen saturations improve. If they do not, there is likely a persistent right to left extrapulmonary shunt.

CHOANAL ATRESIA

In choanal atresia, children present with a history of loud/sonorous breathing SINCE BIRTH. It may sound kind of like stridor. The baby will look and sound worse when at rest because s/he is trying to breathe through a nose that only has one open and functional airway. The child’s respiratory status seems more normal/comfortable when crying and mouth breathing. Signs can include tachypnea and cyanosis.

ASTHMA

PEARL: Asthma is also a high-yield topic for the pediatric boards.

EXERCISE-INDUCED ASTHMA

In exercise-induced asthma, children have bronchospasm and wheezing that is only associated with exercise. Treat with a pre-exercise beta agonist.

PEARL: If there are nighttime symptoms, they are referring to poorly controlled asthma.

PEARL: The differential diagnosis for a child with “exercise intolerance” include neuromuscular issues, anemia, deconditioning, and cardiac disease.

PEDIATRIC ASTHMA CLASSIFICATION

The shortcuts and mnemonics for pediatric asthma classification below may not cover every possible combination of symptoms, but it comes extremely close and should be plenty for the pediatric board exam.

  • INTERMITTENT ASTHMA: Daytime symptoms twice or less per week.
  • MILD PERSISTENT ASTHMA: Three times or more per week (during the day).
  • MODERATE PERSISTENT ASTHMA: Daily symptoms
  • SEVERE PERSISTENT ASTHMA: Continuous symptoms (throughout the day or multiple times/day)
  • PEARL: There is one type of “intermittent asthma.” After that, everything is considered “persistent” (mild, moderate or severe).
  • MNEMONICS:
    • DAYS PER WEEK CUT-OFFS: 2-3-D-C or 23DC provides the cut-offs for classifying asthma based on the frequency of daytime symptoms per week. 2 or less = intermittent. 3 or more = mild. Daily = moderate. Continuous = severe.
    • NIGHTS PER MONTH CUT-OFFS: 2-3-W-N provides the cut-offs for classifying asthma based on the frequency of nighttime symptoms per month. 2 or less per month = intermittent. 3 or more = mild. Weekly or more = moderate. Nightly = severe.
  • PEARL: For nighttime symptoms in young children (0–4 years of age), the classifications are more aggressive and shifted by one category. So, it becomes 0-2-3-W, where once weekly at night is severe.
  • SPIROMETRY– %FEV1 OF PREDICTED: Use the cut-offs below to classify:
    • INTERMITTENT–MILD ASTHMA: > 80% of predicted.
    • MODERATE ASTHMA: 60–80% of predicted.
    • SEVERE ASTHMA: < 60% of predicted.
  • SPIROMETRY AND REVERSIBILITY

REVERSIBILITY refers to an FEV1 that improves by 12% with bronchodilator use. If it does, that diagnoses a reversible obstructive process (asthma). If it does not, then it does not rule out the possibility of asthma. The test has a high positive predictive value only.

  • TREATMENT SHORTCUTS/PEARLS
    • INTERMITTENT ASTHMA: For a patient with intermittent asthma, the intermittent use of short-acting beta agonists (SABAs) as needed is appropriate.
    • MILD PERSISTENT ASTHMA: There are two initial treatment options. The first is a daily low-dose inhaled corticosteroids (ICS) (fluticasone, budesonide, etc.) plus an as-needed SABA. The second is as-needed use for both the ICS and SABA. Inhaled steroids help with both inflammation AND hyper­respon­siveness. Side effects include oral candidiasis, dysphonia (dysphonia), and cough. Leukotriene receptor antagonists (LTRAs) such as montelukast and zafirlukast are alternatives when inhaled steroids are not feasible or not accepted by parents. LTRAs are generally not as effective as ICS.
    • MODERATE PERSISTENT ASTHMA: Per the 2020 asthma guidelines, initial treatment of choice is a single ICS/LABA (long-acting beta agonist) combination inhaler
    • STATUS ASTHMATICUS: Oxygen, albuterol, ipratropium, systemic glucocorticoids and IV magnesium sulfate are all pre-intubation therapies. Options for children unable to cooperate with nebulized treatment (rare) include epinephrine or terbutaline.
    • PEARL: Long-acting Beta Agonists (LABAs) should not be used as monotherapy for prevention of asthma without an inhaled corticosteroid (ICS).
    • PEARL: Leukotriene modifiers (montelukast) have been linked to psychological side-effects, such as depression, suicidal ideation, aggression, and hallucinations.
    • PEARLS: Males, patients with low socioeconomic status, and patients who have had prior intubation have higher mortality rates. Indicators of poor control include frequent ER visits and use of an inhaler 2 or more times per month. Montelukast should be used in patients of any age if the parents don’t want to give inhaled Do not choose to give long-term oral steroids. If a patient has sputum production, that does not rule out asthma.

RHINOVIRUS

Rhinovirus is the most common etiology of a viral asthma exacerbation.

MNEMONIC: Imagine a fat RHINO that gets short of breath and WHEEZES after just a few steps.

RESPIRATORY SYNCYTIAL VIRUS (RSV)

Almost half of the kids who get a severe respiratory syncytial virus (RSV) bronchiolitis go on to develop asthma.

DUST MITES

Dust mite allergies are a common cause of asthma exacerbations. However, limited evidence suggests that viral URI’s are the MOST COMMON cause of an asthma exacerbation.

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