Reactive Airway Disease
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.
Assessment
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 patients 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.
Principles of Treatment
Immediate treatment should be concentrated at relieving bronchospasm and
decreasing mucous production.
Mental Status Changes or Cyanosis: High Flow Oxygen and Epinephrine
(1:1000) 0.3cc SQ)
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.
Nasal cannula 4 l/minute or high flow non-rebreather at > 10 Liters /minute
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.
2.5 mg Albuterol or Proventil Nebulized with 2.5 cc of NS or
4 puffs of MDI inhaler with spacer
Either of the MDI or nebulized therapies should be administered x 3, every 20 minutes.
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.
Prednisone 60mg PO or Solumedrol 125 mg IV push
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.
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Start high flow oxygen by non-rebreather mask with an oxygen flow rate > 10 L/minute.
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Administer Epinephrine (1:1000) 0.3 cc SQ.
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Obtain a full set of vital signs, attach a cardiac monitor, and begin administration of
the first beta-agonist treatment.
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Administer 60 mg Prednisone PO or Solumedrol 125 mg IV push
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Continue beta-agonist therapy until lung sounds are clear or the patient meets admission
criteria as outlined below.
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If discharged, provide MDIs with Prednisone 60 mg QD for 5 days and an appropriate
follow up plan.
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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.
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Start oxygen at 4 L/minute nasal cannula and obtain vital signs.
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Initiate beta-agonist therapy.
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Administer 60 mg PO of Prednisone.
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Provide an intravenous LR or NS 500 cc to 1000 cc bolus.
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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.
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RR > 30; oxygen sat < 92% with continued wheezing or complaint of shortness of
breath.
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Less than 10 percent improvement on peak expiratory flow rate (PEFR).
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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.
References
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Emergency Medicine & Acute Care Essays, volume 16, number 4, April 1992.
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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).