Treatment of Acute Exacerbation of Asthma

Essentials

• The patient, family members, and the physician often underestimate the severity of an acute exacerbation of asthma.
• The aim of the treatment is
  • to restore the condition and the pulmonary functions of the patient to a satisfactory level as soon as possible
  • to maintain an optimal functional status and to prevent exacerbations.

Recognition of an acute exacerbation of asthma

• Occurrence of even one of the following signs means that the attack is severe:
  • wheezing and dyspnoea have increased so that the patient cannot finish one sentence without stopping for breath, or cannot stand up from a chair
  • respiratory frequency constantly 30/min or more
  • heart rate constantly 100-120/min or more (> 30 minutes after salbutamol inhalation)
  • PEF less than 60% of the best previous value
  • oxygen saturation below 90-95%
  • the condition of the patient deteriorates despite treatment.

Signs indicating a life-threatening attack

• Silent respiration sounds in auscultation
• Cyanosis
• Bradycardia or hypotension
• Exhaustion, confusion or unconsciousness
• Arterial blood pO₂<8 kPa even after breathing extra oxygen, arterial pCO₂>6 kPa or decreased pH.

Tests and investigations

• PEF in the beginning of the treatment and in the follow-up
• Pulse oximetry (reveals hypoxia, but not hypercapnia)
• Heart rate and blood pressure
• Arterial blood gas analysis in severe conditions; repeated as needed
• Plasma potassium and blood glucose
• ECG in elderly patients
• Chest x-ray in severe and poorly responding cases to exclude pneumothorax, pulmonary infiltrates, infections and pulmonary oedema
• Exclusion of sinusitis Acute Maxillary Sinusitis

Immediate treatment Inhaled Corticosteroids in the Emergency Department Treatment of Acute Asthma, Intravenous Beta-2-Agonists for Acute Asthma in the Emergency Department, Continuous Versus Intermittent Beta-Agonists in the Treatment of Acute Asthma, Inhaled Magnesium Sulfate in the Treatment of Acute Asthma

1. Put the patient in a comfortable sitting position, legs down if possible, so that he/she can bend forward if needed and have support for the hands and legs.
2. Give oxygen (usually 35% concentration is enough; in resuscitation, maximal concentration and flow) at the rate of 4-5 l/min either through mask or nasal cannulas. If the patient also has COPD Chronic Obstructive Pulmonary Disease (COPD), a lower oxygen flow rate (1-2 l/min) is sufficient in order to avoid CO₂ retention.
3. Give salbutamol aerosol 0.1 mg/dose 4-8 puffs with a spacer Holding Chambers (Spacers) Versus Nebulisers for Beta-Agonist Treatment of Acute Asthma in Adults. Repeat if needed every 20-30 minutes 2-4 times. Alternatively, give a combination of salbutamol 2.5 mg and ipratropium bromide 0.5 mg Ipratropium as an Adjunct to Beta2 Agonists for Acute Asthma nebulized, with or without oxygen (or fenoterol 1.25 mg and ipratropium bromide 0.5 mg). Repeat after 1 hour if needed.
4. Give glucocorticoid intravenously or orally (e.g. 40 mg methyl prednisolone or 125-250 mg hydrocortisone) Corticosteroids for Acute Severe Asthma in Emergency Care and in Hospitalised Patients. Oral glucocorticoids (e.g. 30-40 mg prednisolone) are given independent of the intravenous steroids as soon as the patient is able to swallow.
5. Continue with oral glucocorticoids (e.g. prednisolone 30-40 mg in the morning) for several days. If the patient has continuous glucocorticoid medication at home he/she may require a higher dose.
6. In a life-threatening and severe acute asthma attack, when the bronchodilating medication does not show sufficient effect, consider giving
   • rasemic adrenaline (S2^® Racepinephrine Inhalation Solution, 2.25%) by inhalation at a dose of 0.5 ml in 3 ml of 0.9% NaCl
   • magnesium sulphate 2 g as a single slow intravenous infusion over 20 minutes Magnesium Sulfate in Acute Adult Asthma in an adult patient.
7. If the attack is prolonged, the patient may be dehydrated because dyspnoea prevents drinking. The patient may need fluids 2 000-3 000 ml in excess of normal diurnal need. Caution is needed with old patients and those with heart disease!
8. Non-invasive ventilation (NIV) may be considered in a unit with the possibility for continous monitoring.

Indications for intensive care

• Persistent severe dyspnoea despite short-acting inhaled bronchodilator given with an inhalation spacer repeatedly 3-4 times at 20-30 min intervals or short-acting bronchodilator given with a nebulizer twice at a 30-60 min interval.
  • Alternative dosages
    • Salbutamol 100 µg 2-4 puffs with an inhalation spacer 3-4 times, each at least 20 min apart; then at least 4 hours between subsequent doses
    • Salbutamol 100 µg 2-4 puffs and ipratropium bromide 20 µg 2 puffs with an inhalation spacer 3-4 times, each at least 20 min apart; then at least 4 hours between subsequent doses
    • Salbutamol (2.5 mg) and ipratropium bromide (0.5 mg) 1 dose container; the dose can be repeated, as necessary, after 30-60 min, followed by 1 dose container with an interval of at least 4 hours
• Arterial blood pO₂ is below 8 kPa despite breathing of extra oxygen
• Arterial blood pCO₂ is over 6 kPa
• Exhaustion
• Confusion, drowsiness
• Unconsciousness
• Respiratory arrest

Further treatment

• The patient should not be left alone until the condition has clearly improved.
• Continue oxygen therapy as needed.
• Continue oral glucocorticoid therapy (e.g. 30-40 mg prednisolone/day)Corticosteroids for Preventing Relapse Following Acute Exacerbations of Asthma.
• If the condition is improving, continue nebulisation treatment at 4-hour intervals.
• If the condition has not improved, repeat nebulisation treatment in 20-30 minutes.
• Sedative drugs must not be used in exacerbation of asthma, except in intensive care units.
• Antimicrobial drugs are not indicated if there are no signs of a bacterial infection.

Hospital discharge after acute exacerbation of asthma

• Pulmonary functions must be normalised before the patient is discharged
  • PEF value must be over 70% of reference value or of previous maximal value.
• Upon discharge, make sure that the patient has
  • an oral glucocorticoid (prednisolone [20-]30-40 mg/day) for 5-7 days Corticosteroids for Preventing Relapse Following Acute Exacerbations of Asthma (see also Pharmacological Glucocorticoid Treatment)
  • an inhaled bronchodilator drug
  • an inhaled glucocorticoid Inhaled Steroids in Acute Asthma Following Emergency Department Discharge
  • had the long-term maintenance therapy re-evaluated
  • knowledge of the correct inhalation technique
  • an appointment for the next follow-up visit
  • preferably an own PEF meter at home.