Exercise Induced Asthma

Introduction

Exercise-induced bronchospasm (EIB) describes a transient and reversible contraction of the bronchial muscles after physical exertion that may be associated with dyspnea chest tightness nausea and vomiting symptoms may or may not occur. (EIB formerly known as Exercise-Induced Asthma)[1].

• EIB occurs in 40% to 90% of people with asthma and up to 20% of people without asthma.
• The benefits of regular exercise for all people are well established and activity is an important part of a healthy lifestyle.
• People with EIB may avoid exertion due to symptoms of respiratory failure. Avoiding physical activity has been shown to exacerbate adolescent isolation and can lead to obesity and poor health.
• Exercise has been paradoxically shown to improve acute EIB lung function and reduce airway inflammation in people with asthma and EIB.
• With early detection, confirmation of changes in lung function during exercise and therapy can improve quality of life and, with appropriate management, allow patients to participate in physical activity- discipline without limiting competition among elites.

Epidemiology

• Exercise-induced bronchospasm occurs in 40% to 90% of people with asthma and up to 20% of the population without asthma.
• The proportion of elite athletes ranges from 30% to 70%.
• Exercise-induced cramps are the most common medical problem among winter Olympic athletes especially among speed skiers. Nearly 50% of these athletes suffer from the condition, followed by 43% of short-distance runners.
• Approximately 400 million people are projected to have asthma by 2024 with a large percentage expected to have EIB.
• Every year 250000 people die from asthma complications[1].

Cause

EIB results from a significant increase in the amount of air entering the airways that requires heating and cooling. In susceptible individuals this leads to inflammatory musculoskeletal changes that ultimately lead to symptoms of pulmonary mucosal contraction and dyspnea cough chest hard mucus secretion and sneezing.[1].[3]

Tuberculosis results from a complex interaction between genetic predisposition and multiple environmental influences. The dramatic increase in the prevalence of asthma over the past three decades suggests that environmental factors play a major role in the allergic process. [4]Potential triggers or worsen exercise-induced asthma include:

• Cold air
• Dry air
• Air pollution such as smoke or smog
• High pollen counts
• If you have a respiratory infection like e.g. COVID-1
• Chemicals such as swimming pool chlorine.[5]

Characteristics/Clinical Presentation

Symptoms of exercise-induced bronchospasm can include mild to moderate symptoms of chest tightness with coughing and dyspnea occurring within 15 minutes after 5 to 8 minutes of vigorous exercise training. Reports of severe symptoms leading to respiratory failure and death are rare.

Symptoms:

• it is more likely to occur in specific areas where there is a high concentration of humid humid air or respiratory irritants.
• it typically develops spontaneously within 30 to 90 minutes and results in 1 to 3 hours of inactivity where continued exercise prevents pulmonary artery relaxation. Patients may also be asymptomatic and therefore EIB may be underdiagnosed.

Risk factors include:

• personal or family history of asthma
• personal history of atopy or allergic rhinitis
• exposure to cigarette smoke,
• participation in high-risk sports. High-risk sports include physical activity that exceeds 5 to 8 minutes in certain environments (e.g., hot humid air or chlorinated pools) such as long-distance cycling cross country or downhill skiing ice hockey ice skating high altitude sports swimming water polo and triathlon.
• living and acting in highly polluted environments
• female gender. [1]

Evaluation

A detailed history and examination are important and help establish that exercise is the cause of symptoms.

Pulmonary function tests e.g. spirometry. Standardized diagnostic testing includes both direct and indirect methods and typically involves spirometry measurement of FEV1 change from baseline expressed as a percentage decrease. You may also be referred for Bronchial Challenge Testing[3] e.g

• Direct stimulation of smooth muscle fibers by methacholine has been established to increase pulmonary vasoconstriction. Sensitivity in predicting EIB has been reported to be between 58.6% and 91.1%.
• An indirect test specific for EIB may involve aerobic exercise in a controlled environment with humid humid air because these conditions are known to accelerate EIB in susceptible individuals.
• Alternatives to exercise testing include eucapnic voluntary hyperpnea or hyperventilation of dry air and airway stimulation testing with hyperosmolar 4.5% saline or dry powder mannitol acting to drain the respiratory mucosa to induce EIB among.

Management

Exercise-induced asthma, when properly managed and treated, should not prevent a person from participating in vigorous physical activity at all. Additionally adequate asthma control should allow a patient to participate in any activity of choice without experiencing asthma symptoms[6]. Management of EIB should include identification of any allergens teaching the patient how to avoid asthma triggers and medications when necessary[4]. The EPR 3 Guidelines for the Diagnosis and Management of Fractures medically recommend the following treatments management of EIA[6]:Long-term Drug therapy (if appropriate)Antibiotics such as inhaled corticosteroids used to control airway inflammation have been shown to reduce the frequency and severity of EIB is hard on when used daily for long-term prevention of asthma. In the long run prophylaxis is recommended for patients with poor symptom control including frequent acute episodes of EIB[6]Treatment Before Exercise[6]1. Inhaled beta2-agonists:Short Acting Beta Agonists (SABA), commonly referred to as ‘rescue inhalers’, are used aggressively prior to exercise for control symptoms up to 2-3hoursLong Acting Beta Agonists (LABA) are used in conjunction with inhaled corticosteroids to provide additional protection from asthma symptoms for up to 12 hours.Daily use of LABA is not indicated but should use as a pre-exercise treatment.2. Leukotriene Receptors Antagonists (LTRAs): are drugs used to treat asthma and prevent asthma symptoms. LTRAs have a delayed onset of action and may take several hours to achieve symptomatic relief.3. Exercise Warm-Up: Spending some time warming up before exercise can help reduce symptoms associated with EIB4. Security Colds: Wearing a mask before/during work can help reduce cold-induced EIB

Medication and Competitive Sport

For professional and semi-professional athletes this is a major concern as the issue of drugs in sports and any drugs or drug supplements can have a significant impact.Many sports bodies require athletes professionals and semi-professionals provide evidence of such EIB that a Bronchial Challenge Test has occurred before they are allowed to use EIB drugs during competition. So for any athlete competing at this level before taking any drugs or supplements even if prescribed by your doctor, always check with the relevant authorities.[3]

Physical Therapy Management

See here too! Asthma

Education

In addition to taking medication as prescribed, the following tips can help some people with EIB manage their symptoms:

• Warming up before exercise
• Being as fit as possible – increased fitness raises the EIB threshold so that moderate intensity exercise may not trigger an attack.
• Exercise in a warm, humid environment
• Avoid areas with high levels of allergens that cause irritating gases or airborne particles.
• Breathing through the nose to help warm and cool the air
• Using a mask to remove air although this may not be practical or may make breathing difficult
• Then vigorous exercise is a cooling exercise after breathing through the nose and covering the mouth in cold dry weather
• If client smokes consider talking to a physician about smoking cessation.

Acute Management:Because EIB is triggered by exercise physiotherapists may be the first to notice symptoms of asthma in a patient with undiagnosed EIB. For this reason physical therapists should be aware of the associated signs and symptoms of EIB and any potential red flags to hospitalize and treat them. If a patient develops clinically severe asthma the physical therapist should assess the severity of the attack then place the patient in elevated Fowler’s position for diaphragmatic and pursed-lip breathing if appropriate. If the patient has a inhaler available the physical therapist should provide assistance to self-administer the medication while assisting the patient to relax[7].Duration of useThere are many factors that can inhibit patients who they have EIB permission to exercise one is the belief that exercise is destroying their condition. Although there is insufficient evidence to support relaxation exercises or muscle mass training in patients with asthma there is strong evidence to support the benefits of exercise for cardiovascular training in this patient population Therefore physical therapists can play an active role in managed care through patient education and exercise prescription. A curriculum will improve the effectiveness of physical therapy on the quality of life of children with asthma[8].The Preferred Practice Patterns for this patient population[7] according to the Physical Therapy Guide to Practice[9] include:

• Example 6B: Impairment of Aerobic Capacity/Endurance Associated with Deconditioning
• Example 6C: Breathing Ventilation/Ventilation Exchange and Nondegradation of Ventilatory Capacity/Endurance Associated with Airway Ventilation Practices
• Example 6E: Ventilation and Breathing Damage/Air Exchanger Associated with Air Pump Malfunction or Failure
• Pattern 6F: Ventilatory and Respiratory Disturbances/Ventilation Associated with Respiratory Disorders

Exercise and Medication:

Metered dose inhalation (MDI) should be self-administered approximately 20-30 minutes before the patient participates in exercise. Gentle stretching and exercise warm-ups should also be done during that time to help prevent the onset of asthma symptoms. Physiotherapists should be aware of any side effects or toxic drugs associated with asthma medications. Some symptoms that may indicate drug toxicity include nausea and vomiting tremors anxiety tachycardia arrhythmia and low blood pressure. If the patient exhibits symptoms of asthma while exercising otherwise controlled with current medication the physical therapist should inform the patient’s physician to adjust the dose[7].Vital Signs:It is important for the physical therapist to monitor the patient’s vital signs prior to exercise -exercise and after exercise to detect any abnormal changes in pulmonary lung function. Auscultation of the lungs should be performed regularly to detect any abnormal wheezing breath sounds or the presence of rhonchi. A red flag that could indicate worsening asthma or chemical toxicity could be a bout of tachypnea (respiratory rate above standard values). headache and vomiting. The patient’s chronic asthma-related hypertension may be abnormally elevated[7]Other considerations:Decreased bone mass has been associated with inhaled corticosteroids use time long in patients with moderate to severe asthma. This is chronic corticosteroid use also has an increased risk of primary asymptomatic vertebral fractures. Physical therapists should be aware of the patient’s medical history and exercise caution when performing physical therapy on patients who may be at risk for fracture. Exercise can enhance medical management and play an important role in the care of patients with status asthmaticus. Physical therapists can teach the patient various cough breathing techniques and positioning techniques to help eliminate fluids reduce hypoxemia and increase V/Q a compatibility has improved. Intensive treatments such as energy creation in this population should be avoided to prevent provocation of pneumonia[7].

Differential Diagnosis

Symptoms of chest tightness as a virulent cough and dyspnea on exercise may indicate an infection throughout the airways. Exercise-induced pulmonary fibrosis is not easily diagnosed by clinical symptoms and it is important to obtain objective data showing a decrease in lung function with exercise [1]

Common diagnoses of EIB include[10]:

• Vocal Cord Dysfunction
• Laryngeal/tracheal processes
• Respiratory tract infection
• Gastro-esophageal reflux
• Hyperventilation syndromes

EIB can also be associated with underlying conditions such as[11]:

• COPD
• Obesity
• Pectus Excavatum
• Diaphragmatic paralysis
• Interstitial Fibrosis