Acute Asthma Exacerbation

I. Definition/General Consideration* Asthma: Chronic inflammatory disease of airways characterized by episodic airway obstruction of variable duration and intensity

- Have increased mucus production, smooth muscle constriction, and inflammation* Status asthmaticus: Unremitting asthma symptoms that put a person at risk for respiratory failure* Most common cause of pediatric ER visits* Asthma w/o wheezes = ominious

- Not moving air well at all to be able to wheeze* Triggers: Airway irritants, allergies, exercise, cold weather, respiratory infections, drugs (aspiring, b-blockers), stress, GERD, sinusitis, foods, and food additives

- Trigger increase inflammatory mediator increase tissue hyperreactivity, sensitivity, mucus secretion, inflammation, etc.

II. Clinical Findings* Symptoms

A) Chest congestionB) Persistent or nighttime coughC) Exercise intoleranceD) SOBE) Recurrent bronchitis or pneumoniaF) Irritability

* SignsA) Wheezing, coughingB) Tachypnea, tachycardia, prolonged expirationC) HyperresonanceD) Intercostal and subcostal retractionE) Nasal flaringF) Unable to speak full sentencesG) Cyanosis, diminished breath soundsH) Use of accessory musclesI) Pulsus paradoxus greater than 15J) Reverse with BD

III-IV. Workup/Laboratory Findings* Acute exacerbation workup includes

A) History and physicalB) PFTs or peak flow: Decreased FEV1, decreased FVC, decreased FEV1/FVC ratio, increased FRC, increased RV, increased in FEV1 by 10% after treatment with BDC) Pulse oxD) ABGs: Hypoxia and respiratory acidosisE) WBC: EosF) CXR: Bilateral hyperinflation

V. Differential Diagnosis* Aspiration, foreign body, bronchiolitis, BP dysplasia, CF, GERD, vascular rings, acute BP aspergillosis, pneumonia

VI. Treatment* Algorithm based upon initial assessment:

A) Initial treatment inhaled beta-2, oxygen, consider CS response?1) Good: Symptoms resolve, FEV1 > 70% discharge2) Incomplete: Persistent symptoms, FEV1 < 70 continue treatment reassess PFTs hourly, determine dispo within 4 hrs of starting tx, consider aminophylline IV bolus and drip response

- Good home on systemic CS and f/u- Incomplete dispo based on severity, duration, PFTs, psych, access- Poor admit to hospital

3) Failure: Severe S/S, FEV1 < 25%, pCO2 > 40 see belowB) Respiratory failure Intubate, ventilate, nebulized beta-2, admit to ICU

* Pharmacologic treatment of acute asthmaA) B2 agonis (ventolin or proventil)t: 0.5 mL neb q20 min (dilute in 2 mL NS) or 4-8 puffs inh q20 minB) Anticholinergic (ipratropium): 2.5 mL neb q20 min or 2-4 puffs inh q20 minC) CS: 40-60 mg PO qd in single or divided doses or 60-80 mg IV q6-8hD) OxygenE) Follow PFTs, pulse ox, and CXR serially

* Can give epi to status asthmaticus patients