Reactive airway disease (RAD), frequently referred to as asthma, may occur from a variety of bronchial stimuli. Traditional irritants include smoke, exercise, change in weather/humidity, or respiratory infections. Other causes include foreign body aspiration, early pulmonary edema, COPD exacerbation, or bronchiolitis in infants. Pathophysiology involves the production of mucous and bronchospasm. Immediate treatment is directed at these two entities.

Immediate assessment is clinically based; do not rely on arterial blood gases or chest radiographs. Vital signs, to include pulse oximetry, along with rapid assessment of the patient’s work of breathing should be initially ascertained. Particular attention should be paid to mental status, ability to speak in full sentences, use of accessory muscles, retractions or evidence of respiratory failure secondary to tiring. Auscultation of the chest should center on determining whether there is prolongation of the expiratory phase and/or presence of wheeze. Other objective findings include diaphoresis, inability to lie supine, a respiratory rate > 30, and a low peak expiratory flow rate (PEFR). Patients with several objective findings should be monitored more closely and considered for admission.

Immediate treatment should be concentrated at relieving bronchospasm and decreasing mucous production.

Oxygen
Most patients will benefit from oxygen therapy even without evidence of hypoxia. The benefits occur because oxygen is a mild bronchodilator and can assist in the V/Q mismatch transition that is expected after initiating nebulized therapy as outlined below.

Beta Adrenergic Therapy (mainstay of therapy)
Stimulation of beta-2 receptors in the lung leads to production of cyclic AMP. This results in relaxation of bronchial smooth muscle. Inhaled beta agonists are preferred and may be repeated or given continuously, depending on severity, with close monitoring. Adding a spacer to a metered dose inhaler (MDI) is as effective as nebulized medication.

Steroids
Failure to include early steroids in a treatment plan has been shown to be one of the leading causes of subsequent death from asthma. Oral dosing has been proven to be as efficacious as parental administration. Treatment of the inflammatory component of asthma with inhaled steroids is the mainstay of prophylaxis in moderate asthma.

Other medications
Theophylline, magnesium, and anticholinergics have not been proven to be more effective than giving additional beta agonists. Therefore, they should be considered as adjunctive therapy.

Treatment Regimens Examples

A 25 year old male presents with acute onset of SOB, wheezing, and is unable to speak in full sentences. He has central cyanosis and is confused.

• Start high flow oxygen by non-rebreather mask with an oxygen flow rate > 10 L/minute.

• Administer Epinephrine (1:1000) 0.3 cc SQ.

• Obtain a full set of vital signs, attach a cardiac monitor, and begin administration of the first beta-agonist treatment.

• Administer 60 mg Prednisone PO or Solumedrol 125 mg IV push

• Continue beta-agonist therapy until lung sounds are clear or the patient meets admission criteria as outlined below.

• If discharged, provide MDIs with Prednisone 60 mg QD for 5 days and an appropriate follow up plan.

• May consider Magnesium Sulfate 2 gms IV and/or Ipratroprium Bromide (Atrovent) by nebulizer or MDI.

A 32 year old female with known mild asthma who presents with increasing wheezing over the past 2 days associated with congestion and cough worse at night. The respiratory rate is 20 and the oxygen saturation is 92%. She is alert and able to speak 5 word sentences. Expiratory wheezing is noted on auscultation.

• Start oxygen at 4 L/minute nasal cannula and obtain vital signs.

• Initiate beta-agonist therapy.

• Administer 60 mg PO of Prednisone.

• Provide an intravenous LR or NS 500 cc to 1000 cc bolus.

• Discharge on MDIs and Prednisone with appropriate follow-up.

Admission / MEDEVAC Criteria

If after three beta-agonist treatments, the following criteria should be assessed and the patient referred for specialty care.

• RR > 30; oxygen sat < 92% with continued wheezing or complaint of shortness of breath.

• Less than 10 percent improvement on peak expiratory flow rate (PEFR).

• RAD associated with any lobar pneumonia.

Patients can be admitted to a sick call holding area for continuous oxygen and Q 2 to 4 hour beta-agonist treatments if a MEDEVAC or specialty referral is not accessible.

1. Emergency Medicine & Acute Care Essays, volume 16, number 4, April 1992.

2. Executive Summary: Guidelines for the Diagnosis and Management of Asthma, U.S. Department of Health and Human Services, June 1991.

Prepared by LCDR Kathryn Hall-Boyer, MC, USN. Reviewed and revised by LCDR Jeffrey Disney, MC, USN, Naval Medical Center San Diego, San Diego, CA (1999).