asthma
ASTHMA
Asthma is a chronic inflammatory disease of the airways in the lungs of children and adults.
The patient usually complains of shortness of breath, chest tightness and coughing with wheezing.
Goals of treatment are effective symptom control with minimal or no exacerbations, minimal or no nocturnal and daytime symptoms, no limitations on activities, minimal or no need for reliever treatment, and minimal adverse effects of medication.

Asthma Management

Monitoring

Patient's Response 1 Hour After Initial Emergency Department Therapy

  • Lung function should be measured after 1 hour, after administration of 1st 3 bronchodilators, and in patients with disease progression despite intensive bronchodilator and steroid therapy, to evaluate the need for ICU transfer
Moderate Exacerbation
  • FEV1 or PEF >60-80% predicted or personal best
  • Improved symptoms
  • Consider for discharge
Severe Exacerbation
  • FEV1 or PEF <60% predicted or personal best
  • Symptoms not improving
  • Continue treatment and reassess at regular intervals
Patient Response After Hospital Admission
Consider Admission to ICU if:
  • Severe asthma and no response to initial therapy in the emergency department or worsening asthma despite therapy
  • Signs of imminent respiratory arrest (eg confusion, drowsiness, loss of consciousness)
  • Hypoxemia despite supplemental O2 which is indicative of impending resp arrest:
    • PaO2 <60 mmHg (8 kPa) and/or PaCO2 >45 mmHg (6 kPa) or SaO2 by oximetry 90% in children

Intubation

  • Consider if there is continued deterioration despite optimal therapy
  • Exhausted patient and/or PaCO2 is increasing

Consider Home Discharge

  • PEF >60-80% predicted/personal best, SaO2 >94% room air and is sustained on oral/inhaled medication

Considerations Prior to Discharge

  • For patients with good response to treatment being considered for discharge, ensure that the patient has adequate resources at home and advise to contact clinician urgently if with worsening of symptoms
  • Provide a guided self-management plan to all patients with asthma:
    • Educate the patients about significant symptoms that should be monitored
    • A written asthma action plan (Please see Patient Education section for further information)
    • Stress the importance of adherence to prescribed medications, preventive strategies for exacerbations, and follow-ups
  • Arrangements for follow-up after 2-7 days should be done

Prevention

  • Avoiding or reducing risk factors is an effective way to prevent the development of asthma and decrease exacerbation

Prevention of Asthma

  • Preventing the development of atopy and asthma in infants and children may be started before and after birth
    • Avoid tobacco exposure
    • Breastfed infants have lower incidence of wheezing illnesses during early childhood
      • Infants who are exclusively breastfed for 3-4 months have lower risk for childhood asthma
    • Broad-spectrum antibiotic use should be avoided during the 1st year of life 
    • There is insufficient data supporting the need for prescribing antigen-avoidance diet to high-risk pregnant mothers and for the role of probiotics
Prevention of Asthma Symptoms and Exacerbation
  • Treating modifiable risk factors and comorbidities is the key to asthma exacerbation prevention
  • Asthma exacerbation is usually triggered by various factors (eg allergens, viral infections, pollutants, drugs)
    • Decreasing patient’s trigger exposure improves asthma control and reduces medication use

Indoor Allergens

  • Domestic mites
    • Encasing mattresses, washing linens with hot water, removing dusts and reducing habitats of mites may help decrease exposure
  • Furred animals
    • There are conflicting evidences on the effect of pet allergens on patients with asthma 
    • Elimination from home is encouraged, however, allergen levels are only decreased many months after complete removal of the animal
  • Cockroaches
    • Eliminate suitable environment, limit their access, control by use of chemical or trapping
  • Fungi
    • Dampness, visible mold and mold odor should be eliminated as studies suggested that exposure to these home allergens increase the risk of developing asthma

Outdoor Allergens

  • Reduce exposure by closing the doors or windows, staying indoors when pollens and mold counts are high, and by using air conditioners

Outdoor Air Pollutants

  • Increased level of air pollution is associated with asthma exacerbation
    • Current evidence shows that 13% of global asthma incidence in children is due to traffic-related air pollution
  • Thunderstorms, temperature and humidity changes occasionally increases asthma symptoms
  • Patients with uncontrolled asthma should not be engaged in any strenuous physical activity in cold weather, low humidity, or high air pollution
    • They should refrain from any smoke-filled area
    • They should stay in a climate-controlled place

Occupational Exposure

  • Responsible for considerable number of asthma cases in adults
  • Early recognition of work sensitizers and avoidance of exposure are important

Food and Food Additives

  • Common primarily in children
  • When food allergy is confirmed, it should be avoided
  • Sulfite, a common preservative found in processed potatoes, shrimp, wine, beer, dried fruits, etc, is implicated in asthma exacerbation in 5% to 10% of asthmatics 

Drugs

  • Aspirin and NSAIDs have been implicated in asthma exacerbation
  • Beta-blockers may aggravate bronchospasm
  • Excessive use of short-acting beta2-agonists (>1 200-dose canister/month) may exacerbate flare-ups

Influenza Vaccination

  • Yearly vaccination is recommended in patients with moderate to severe asthma

Obesity

  • Increased body mass index (BMI) is associated with asthma, but reason behind is still unknown
  • Weight reduction improves lung function, symptoms, disease occurrence and health status of obese asthmatics

Physical Activity

  • Light to moderate tolerable exercise should be encouraged especially for patients with comorbidities caused by weight problems
    • Sufficient warm-up before training may increase tolerance for exercise
  • Lack of exercise in children may lead to poor metabolism and may lead to obesity
  • Patients with exercise-induced asthma should be advised accordingly
    • A reliever medication prior to exercise may be prescribed

Others

  • Extreme emotional expression and panic attacks may cause hyperventilation and hypocapnia, which leads to airway narrowing
  • History of intubation or confinement to ICU for asthma increases the risk for exacerbations
  • Rhinitis, sinusitis, polyposis, andpo gastroesophageal reflux can exacerbate asthma

Follow Up

  • Previously seen patients at primary care due to an exacerbation who were discharged after effectively responding to initial treatment should return for follow-up within 2-7 days after discharge
  • Patient should be monitored 1-3 months after the 1st consultation, and then every 3-12 months thereafter
  • After an exacerbation, patient should be seen within 1 week to 1 month until with good symptom control and has reached or surpassed personal best lung function
  • Lung function should be assessed and recorded at least every 1-2 years

COVID-19 and Asthma

  • Prescribed asthma medications should be continued particularly inhaled and oral corticosteroids
    • For severe asthma, biologic therapy should be continued and oral corticosteroids should not be abruptly stopped
  • Nebulizers should be avoided if possible as it may increase risk of spreading the virus to other patients and to healthcare professionals
    • Preferred treatment during severe exacerbations is pressurized metered-dose inhaler via a spacer with mouthpiece or tightly fitting face mask if needed
  • Spirometry should be avoided in confirmed/suspected COVID-19 patients

Specialist Referral is Recommended in the Following:

  • Patient had life-threatening asthma exacerbation
  • Atypical clinical findings, eg clubbing, crackles, cyanosis, heart failure (HF), stridor, hemoptysis; and children with abnormal voice or cry, dysphagia, focal signs in the chest, inspiratory stridor
  • Excessive vomiting or possetting in children
  • Persistent cough and/or sputum production; and children with persistent productive cough despite proper inhaler technique and good treatment adherence
  • Persistent SOB (not episodic and without associated wheeze)
  • Spirometry or PEF findings do not indicate asthma and requires additional testing (skin allergy testing, provocative challenge test)
  • Symptoms present from birth or perinatal lung problem and has family history of unusual chest disease
  • Unilateral or fixed wheeze
  • Weight loss
  • Patient is not responding to therapy after 3-6 months, needs step ≥4 care, or being considered for immunotherapy
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