- What Is
What is an eucapnic hyperventilation (EVH) test?
Eucapnic voluntary hyperventilation (EVH) is a provocative test to diagnose exercise-induced airway narrowing (exercise-induced bronchospasm).
Which individuals require eucapnic hyperventilation (EVH) test?
Eucapnic voluntary hyperventilation (EVH) is usually done for below individuals:
- Occupations in which asthma needs to be excluded, such as divers and army personnel
- In professional athletes to prove that they have exercise-induced bronchospasm (EIB) and hence need to take medications for the same during a competition
- To evaluate young active-duty soldiers in the military for unexplained shortness of breath
In which patient conditions eucapnic hyperventilation test shouldn’t be done?
Eucapnic voluntary hyperventilation (EVH) shouldn’t be done in
- Patients with seizures
- Pregnant women
- Patients who may develop breathing problems due to spirometry
- Patients with a recent severe asthma attack or any other respiratory disease
- Patients who had heart disease condition within three months prior to EVH test
- Patients with uncontrolled hypertension
What should a patient avoid prior to an eucapnic hyperventilation test?
Eucapnic voluntary hyperventilation (EVH) is a painless test, and patients may need to be calm, which can help them during breathing challenges.
- Patients may need to avoid smoking at least six hours before the test because it may give false-positive results.
- Patients may need to avoid heavy meals or any alcoholic drinks. Patients might also need to avoid spicy foods and caffeine-containing drinks (which may cause heartburn, indigestion, or reflux) on the day of the procedure.
- Patients may be asked to avoid any strenuous exercise or excess exposure to cold/hot air within four hours prior to the test.
- Certain medications, such as steroids bronchodilators, need to be taken many hours prior to the procedure. Doctors may usually advise the patients regarding medications a day prior to the procedure.
What happens during the eucapnic hyperventilation test?
The eucapnic voluntary hyperventilation (EVH) test was designed to mimic the effect that prolonged exercise has on the airways. The procedure usually takes between 60 and 90 minutes depending on the patient’s breathing and further procedures.
- Spirometry testing will be done before and after the six-minute test. Spirometry is a test that measures how much and how fast a patient can force air out of their lungs. A value called FEV1 obtained during the spirometry test is used as a parameter during the test.
- The patient uses a nose clip to prevent air escape.
- During the procedure, the patient breathes a specific gas mixture (21% oxygen, 5% carbon dioxide, and balance nitrogen) at high minute ventilation.
- The patient actively hyperventilates for a total of six minutes.
- Spirometry testing is done at the end of the test and 5, 10, 15, and 20 minutes after the breathing challenge to measure FEV1.
- The test is considered positive if FEV1 falls to less than 10% of the pre-test value.
- Depending on FEV1 levels, bronchospasm is classified as mild, moderate, and severe (severe >30% fall in FEV1).
- The doctor may perform a laryngoscopy procedure after the breathing challenge. During laryngoscopy, the doctor will place a fiber optic probe (small tube) in the patient’s nose. The tube is passed through the nose to the back of their throat. The movement of the vocal cords can be seen with the probe.
Health Solutions From Our Sponsors
Medscape Medical Reference
Top What Is an Eucapnic Hyperventilation EVH Test Related Articles
Asthma Attack SlidesAsthma symptoms include coughing, wheezing, headache, fatigue, dark circles under the eyes, trouble sleeping, and loss of appetite. Learn asthma signs and symptoms in adults and kids so you can follow your asthma action plan and know when to seek medical care for an asthma emergency.
What Is Asthma? 19 Complex FactsThere are many unusual symptoms of asthma, including sighing, difficulty sleeping, anxiety, chronic cough, recurrent walking pneumonia, and rapid breathing. These symptoms may vary from individual to individual. These asthma complexities make it difficult to accurately diagnose and treat asthma.
Asthma in Children
Asthma in children manifests with symptoms such as coughing and wheezing. Rates of asthma in children are increasing. Asthma in children is usually diagnosed based on the description of symptoms. Lung function tests may also be used. A variety of medications are used for the treatment of childhood asthma.
Asthma MedicationsThere are two types of asthma medications: long-term control with anti-inflammatory drugs and quick relief from bronchodilators. Asthma medicines may be inhaled using a metered-dose inhaler or nebulizer or they may be taken orally. People with high blood pressure, diabetes, thyroid disease, or heart disease shouldn't take OTC asthma drugs like Primatene Mist and Bronkaid.
Asthma Myths SlideshowWhat are asthma myths and facts? There is currently no cure for asthma, and no specific, single cause for asthma has been identified. Take this quiz on asthma myths to test your asthma IQ.
AsthmaAsthma is a condition in which hyperreactive airways constrict and result in symptoms like wheezing, coughing, and shortness of breath. Causes of asthma include genetics, environmental factors, personal history of allergies, and other factors. Asthma is diagnosed by a physician based on a patient's family history and results from lung function tests and other exams. Inhaled corticosteroids (ICS) and long-acting bronchodilators (LABAs) are used in the treatment of asthma. Generally, the prognosis for a patient with asthma is good. Exposure to allergens found on farms may protect against asthma symptoms.
What Is Asthma? Symptoms, Causes, and TreatmentsWhat is asthma? What is the main cause of asthma? Learn information about asthma, a chronic disease of the bronchiole tubes. Discover information about asthma attacks, complications of asthma, and how to control an asthma attack.
Asthma QuizAsthma is a chronic disease of the airways of the lungs, which can be managed with proper treatment. Triggered by two main causes, asthma symptoms can be brought on by environmental factors and surprising allergens.
Asthma: Over the Counter TreatmentPatients who have infrequent, mild bouts of asthma attacks may use over-the-counter (OTC) medications to treat their asthma symptoms. OTC asthma medicines are limited to epinephrine and ephedrine. These OTC drugs are best used with the guidance of a physician, as there may be side effects and the drugs may not be very effective.
COPD vs. Asthma (Differences and Similarities)COPD (chronic obstructive pulmonary disease) and asthma both have common symptoms like coughing, wheezing, shortness of breath, and a tight feeling in the chest. COPD is caused by tobacco smoking, while asthma is caused by your inherited genetic makeup and their interactions with the environment. Risk factors for asthma are obesity, exposure to cigarette smoke (even secondhand smoke), and personal history of hay fever. There is no cure for either disease, but symptoms can be managed with medication. A person with asthma has a better prognosis and life expectancy than someone with COPD.
Natural Ways to Ease Asthma SymptomsYou can do more than take medication to manage your asthma. Several other things can help you breathe more easily.
Nebulizer for AsthmaAsthma nebulizers, or breathing machines, convert liquid medication into mist for easy inhalation.
What Are the Most Common Surgical Airway Techniques?Surgical airway management involves the creation of an airway using surgical techniques. The four distinct but related most common surgical airway techniques include open cricothyroidotomy, needle cricothyroidotomy with jet oxygenation, percutaneous cricothyroidotomy using the Seldinger technique, and surgical tracheostomy (an incision in the windpipe made to relieve an obstruction to breathing).
Understanding Ventilator GraphicsVentilator graphics are an important part of treating patients who are on mechanical ventilation. Ventilator graphics help in understanding the pathophysiology in mechanically ventilated patients. The ventilator displays waveforms that help the physician to identify and manage any patient-ventilator asynchrony, often in intensive care (ICU) settings. Examples of ventilator graphics include ventilator waveforms, arterial waveforms, venous waveforms (central venous pressure [CVP]), intracranial pressure waveforms, and intra-aortic balloon pressure waveforms.
What Are Video Laryngoscopy and Fiberoptic-Assisted Tracheal Intubation?Tracheal intubation, also called intubation, involves placing a flexible plastic tube (endotracheal [ET] tube) into the trachea (windpipe) to maintain an open airway, ventilate the lungs, or administer certain drugs. Video laryngoscopy is a form of indirect laryngoscopy in which the physician does not directly inspect the larynx. Fiberoptic intubation involves inserting an ET tube over the shaft of a flexible fiberoptic scope for visualization. Video laryngoscopy and fiberoptic laryngoscope aid in tracheal intubation.