1. Amelia Mangune Posted Date Jun 23, 2022, 12:05 AM Unread
Amelia MangunePosted DateJun 23, 2022, 12:05 AMUnreadAsthma Asthma is a chronic
respiratory disease associated with reversible airflow obstruction, bronchial
hyperresponsiveness (BHR), and airway inflammation triggered by various stimuli,
including viral upper respiratory infection, environmental allergens, and occupational
exposures. It can lead to recurrent episodes of wheezing, cough, and dyspnea (Holguin,
2017). Presentation (Holguin, 2017) H&P reveals recurrent respiratory symptoms
characterized by wheezing, cough, and chest tightness. Trigger exposures may exacerbate
respiratory symptoms and include exposure to airway irritants (smoke, strong fumes, air
pollution, etc.), aeroallergens, respiratory infections, and cold air. Psychological stress and
physical exercise may also trigger respiratory symptoms without any other concomitant
exposures.Respiratory symptoms may have a nocturnal predominance and are frequently
more severe in the morning after waking up when airflows are usually lower. Other
presentation includes tachypnea, tachycardia, non-productive cough, prolonged expiration,
use of accessory muscles in severe attack, and decreased exercise tolerance (Bray,
2018).Categories of Asthma Severity (Fanta & Barrett, 2022)Intermittent:Daytime asthma
symptoms happen 2 or fewer days per week.Two or fewer nocturnal awakenings per
month.Use short-acting beta-agonists (SABAs) to relieve symptoms two or fewer days per
week.No interference with normal activities between exacerbations.FEV1 measurements
between exacerbations are consistently within the normal range (i.e., ≥80% of
predicted).FEV1/FVC ratio between exacerbations is normal.One or no exacerbations
require oral glucocorticoids per year.Mild persistent:Symptoms > 2Xweekly (although <
daily).About 3-4 nocturnal awakenings per month due to asthma (but fewer than every
week).Use SABAs to relieve symptoms > 2 days/week (but not daily).Minor interference
with normal activitiesFEV1 measurements within normal range (≥80% of
predicted).Moderate persistent:Everyday manifestations of asthma.Nocturnal awakenings
as often as once per week.Daily requirement for SABAs for symptom relief.Some limitations
in normal activity.FEV1 ≥60 and <80% of predicted and FEV1/FVC below normal.Severe
persistent:Presence of asthma symptoms throughout the day. Nocturnal awakening due to
asthma every night. Reliever prescription needed for symptoms several times/day. Severe
activity limitation due to asthma. PathophysiologyThe early phase of asthma (1st hour) is
triggered by IgE antibodies that are sensitized and released by plasma cells (Sinyor & Perez,
2022). Based on Sinyor & Perez (2022), these antibodies respond to environmental triggers.
IgE antibodies then bind to high-affinity mast cells and basophils. When a pollutant or risk
2. factor gets inhaled, the mast cells release cytokines and eventually de-granulate. Released
from mast cells are histamine, prostaglandins, and leukotrienes. These cells, in turn,
contract the smooth muscle and cause airway tightening. In the late phase (4-6 hrs),
eosinophils, basophils, neutrophils, and helper and memory T-cells all localize to the lungs,
which causes bronchoconstriction and inflammation. As a result of inflammation and
bronchoconstriction, there is an intermittent airflow obstruction, resulting in increased
work of breathing.Labs/Diagnostics (Holguin, 2017) Pulmonary Function TestReveals
evidence of airway obstruction with a bronchodilator response > or = 12% (or 200 mL)
improvement of FEV1 after short-acting bronchodilators.Bronchodilation should only be
evaluated after withholding asthma medications for at least 4 hrs for short-acting β2-
receptor agonists (SABA) and 24 hrs for long-acting β2-receptor agonists
(LABA).Methacholine (a cholinergic agent utilized to stimulate bronchial constriction
excludes asthma). A positive test occurs when a reduction in FEV1 > or = 20% from the
baseline postmethacholine level. The methacholine test is very sensitive but lacks specificity
so that a positive test can be seen in other airway diseases or allergies. Diligent assessment
for the existence or lack of asthma through testing and evaluation of treatment response
will help eliminate the roughly 30% of patients who are mistakenly diagnosed with this
condition clinically (false positive) and are unnecessarily treated with corticosteroids.Other
studies (Bray, 2018)SpirometryAllergy testing (consider)Peak flow monitoringDifferential
Diagnosis (Holguin, 2017): Congestive heart failure Wheezing and coughing can happen,
which may be linked with airway vascular congestion and peribronchial cuffing due to
pulmonary edema, bibasilar inspiratory crackles on auscultation, and an elevated serum
BNP. Airway obstruction Foreign body aspiration, tumor, laryngeal edema, anaphylaxis, and
laryngospasm could lead to stridor, which can be mistaken for wheezing.Other differential
diagnoses (Bray, 2018)Respiratory infectionGERDHabitual non-asthma-related
coughTuberculosisTreatment (Holguin, 2017) Supplemental O2Inhaled
SABA Anticholinergic agentsNebulizersOral systemic corticosteroidsPatient Education and
Prevention (Bray, 2018):Identify and minimize known asthma triggers by avoiding
allergens and irritants.Take prescribed asthma medications daily.Learn how to identify
early signs/symptoms of asthma exacerbation (frequency of dyspnea, cough, chest
tightness, and the need for quick-relief medication).Have an “asthma action plan,” a
preplanned medication plan for an exacerbation.Influenza and Pneumococcal Pneumonia
vaccinations.Monitor peak flow values.Learn the correct use of inhalers, spacers, and other
medications (about half of patients misuse inhalers, causing medications
ineffective).Routine follow-up visit ( 1 to 6 mons depending on the severity of
asthma).Referrals (Fanta & Barrett, 2022)Pulmonologist If there is uncertainty about
asthma diagnosis, poorly-controlled asthma, an episode of near-fatal asthma, treatment of
comorbid conditions, or the need for bronchoscopy.Allergist/Immunologist If considering
the need for specialized diagnostic studies (e.g., allergy skin testing) or potential treatment
with biologics.ReferencesBray, S.L. (2018). Asthma. In Hollier, A. (Ed). Clinical Guidelines In
Primary Care (2nd Ed, pp. 662-669). Advanced Practice Education Associates, Inc.La
Fayette, LA.Fanta, C.H. & Barrett, N.A. (June 06, 2022). An overview of asthma management.
UpToDate. https://www.uptodate.com/contents/an-overview-of-asthma-
3. management?source=history_widget#H31Holguin, F. (2017). Asthma. In McKean, S.C., Ross,
J.J. Dressler, D.D. & Scheurer, D.B. (Eds.). Principles and Practice of Hospital Medicine (2nd
ed., Chap. 231, pp. 4507-4509). McGraw-Hill Education. Sinyor, B. & Perez, L.C. (May 08,
2022) Pathophysiology of asthma. Retrieved from
https://www.ncbi.nlm.nih.gov/books/NBK551579/
