Introduction
Asthma is a respiratory disease which is affects the airways. It is usually a chronic inflammatory disease which occurs slowly to patients and in most case, it cannot be cured. For patients suffering from asthma, developing exacerbations is very easy which can in turn lead to a respiratory failure. To be successful in the management of asthma, it is crucial that all patients at risk are identified and a through assessment and give the appropriate treatment at the appropriate time. An acute asthma attack can lead to confusion to the patient and even the people who are supposed to be caring for the patient. Acute asthma attacks are one of the most emergency conditions which medical practitioners encounter. Deaths from acute asthmatic attacks occur mostly to the elderly and people living in the rural areas who do not have an easy access to the doctors or other health practitioners. Some of the deaths which occur due to acute asthmatic attack can be controlled if the severity of the asthma and attack were recognized in advance.
Management of Acute Asthmatic Attack
Asthma attacks can be adequately managed in outpatient care but if it is poorly controlled or it is in severe cases, it can be challenging to manage. The main aim of asthma management is to control the symptoms associated with it and prevent development of exacerbations. Before a health practitioner starts on the management of the patient, they should first get a brief history about the patient and do a rapid physical examination. A wheeze should not be relied on as the indication for the severity of the asthma attack. In some cases, a wheeze may be absent in cases of an acute asthmatic attack. Acute asthmatic attacks should be managed in a high density unit (HDU) since it a very serious condition which if care is not taken can be fatal. In management of an acute asthmatic attack, it is crucial that the doctor goes step by step
Initial Assessment of Asthma Severity
Once the patient is brought in the HDU, the doctor gets a brief history and does a physical examination which helps in identifying the immediate needs of the patient. This information helps in identifying factors which can increase mortality rate. In the history information is collected on previous acute exacerbations, prior endotracheal intubations, previous admissions in HDU, increased use of short acting beta 2 agonists (SABAs) and if there is history of withdrawal of systemic steroid use. This information is useful in determining the severity of the asthmatic attack directing the doctor to start a comprehensive management. Physical examinations include assessment of body activities like breathlessness, changes in the mental status of the patient, changes in heart rate, respiratory rate, presence/absence of wheezing, if the patient if utilizing accessory muscles or if there is presence of pulsus paradoxus. The doctor does all these physical examinations because the presence or absence of any of these determines whether or not the asthmatic attack is severe or not. It also helps in determining the level of severity.
Taking a brief history of the patient will help in knowing the behavior which could or could not trigger an acute asthmatic attack. Some of the information collected from the brief history and the physical assessment of the patient will require the doctor to perform assisted ventilation on the patient. Some symptoms which can mandate the doctor to perform assisted ventilation include; cyanosis, difficult in speaking, respiratory problems, severe agitation or confusion, some indication of a muscle fatigue and absence of wheezing. For patients who have developed exacerbations, the doctor should perform frequent physical examinations most especially after a therapeutic procedure. Since the patient is being managed in the HDU, peak expiratory flow rate (PEFR) is the measurement which is appropriate for determining how the patient is responding to treatment and determine the level of airway obstruction. The doctor can also do oxygen saturation or blood gas analysis which is used to indicate if there is hypoxemia. Hypoxemia is a clear indication of an acute severe asthmatic attack. For the patient to be classified as one who is suffering from an acute asthmatic attack, the initial assessment and evaluation should show a PEF 33-50% best or predicted. After the initial evaluation and assessment of the severity of the asthmatic attack, the doctor can go ahead depending on the information collected from physical assessment and the brief history.
Initial Management in Acute Asthmatic Attack which does not Require Mechanical Ventilation
The first step in managing acute asthmatic with development of exacerbation is correction of hypoxemia by supplementing oxygen. In most of times supply with additional oxygen should start early enough even before the patient enters HDU but is continued when the patient has already been admitted. The additional oxygen supply should be provided in such a way that oxygen saturation is kept at SaO2 of above 90%. This is supposed to be higher at above 95% for pregnant patients and patients suffering from another heart disease. As this additional supply of oxygen is given, the one undertaking the activity should keep checking the oxygen saturation just to ensure that a response to bronchodilator therapy happens.
Inhaled Bronchodilator Therapy
These are various medicines which are used for inhaling. They of various types including;
SABAs
SABAs used to inhale have been highly promoted to be used in patients who have acute asthmatic attack especially if they develop exacerbations. The mostly used SABAs are the beta 2 selective type which include; albuterol, bitolteral and pirbuterol. These types are mostly used because they come with reduced probability of developing cardiotoxicity even if administered at high doses. This is in comparison with other non selective types. According to studies done comparing the effective of intermittent and continuous admission of these drugs, continuous admission has shown reduction in the number of times for hospitalization. Patients who suffer from severe highway obstruction have been found to improve a lot if betas 2 selective SABAs are administered continuously. Especially in the patients who are being managed in HDU have shown a positive response to treatment when these kind of drugs are used. There two methods which can be used to give inhaled SABA. The first one is meter dose and the second one is spacer device or a nebulizer. Whether the patient gets the inhaled SABA by either of the two methods, the response is the same. For patients with severe acute asthmatic attack in HDU, they may not be able to inhale the medicine when using meter dose. However, these patients use nebulizer. For instance, in 2.5 mg nebulized albuterol which is equivalent to 6-12 puffs is required for a successful response and attainment of bronchodilation.
When we consider racemic albuterol which is used to manage patients with acute asthmatic attack, we can see that it is available as R-albuterol and S-albuterol. These two have been found to differ especially in their pharmacologic properties. R-albuterol has been found to show bronchodilator properties while S-albuterol has been found to be effective as it leads to improvements in airway responsiveness. The type of R-albuterol which has been recommended for use in clinical conditions is known as Levalbuterol or can be termed as R-stereoisomer of albuterol. Studies done on Levalbuterol have proved that it is more appropriate in treating acute asthma as compared to racemic types of albuterol. It is more appropriate when we compare changes which occur in terms of duration taken when in emergency care, number of times one is hospitalized and physiological changes on the patient. Levalbuterol have shown positive change in all these parameters. For patients who are put on Levalbuterol their spirometric response is far more better as compared to patients ho use other types of albuterol. Levalbuterol is a very expensive drug and therefore, further studies need to be done to determine the role which it plays in treating acute asthma.
Anticholinergics
β2-agonists have been the mostly used as the first line bronchodilating agent in management and treatment of acute asthmatic attacks. However, there have been suggestions that ipratropium bromide to be used as an additive treatment. According to the study on the effect of β2-agonists and ipratropium bromide combined together in the treatment of acute asthmatic attack, it showed a lot of improvements pertaining airflow obstruction. However, children have shown better improvements after the combined dose as compared to the response shown in adults. When ipratropium bromide and albuterol are used together, the side effects were reduced specifically because of the ipratropium bromide. This is due to the fact that ipratropium bromide has shown a positive response in patients with acute asthma in terms of improving bronchodilation and it comes with no side effects on the patient. Therefore, it is advisable that the combination be used in treatment and management of acute asthmatic attacks especially where exacerbations develop.
Corticosteroids
Especially for patients with exacerbations due to acute asthma, systemic corticosteroids can be effective. The important thing about systemic corticosteroids is that it leads to increased improvements in terms of airflow obstruction, reduce the number of times one is hospitalized and reduces the rate of relapse after treatment. However studies on the doses of corticosteroids have produced different results. Even low doses have shown an increased positive response. The most preferred way to give a corticosteroid dose is oral means since it has proved to be more effective as compared to intravenous route. Apart from oral corticosteroid, inhaled corticosteroid has also proved to be effective in that it reduces the number of times one is admitted in the hospital. Inhaled corticosteroid has leads to improvements in peak expiratory flow rate as well as PEV1. Treatment and management of acute asthma with it has been very successful and there were very few side effects identified.
Methylxanthines
Methylxanthines is not recommended in the management of acute asthma especially the one which leads to development of exacerbations. The study done on children with acute severe asthma in HDU showed that the level of response was very low when Methylxanthines was used for treatment and management. However the same study proved that if aminophylline was combined with Methylxanthines, FEV1 and PEF improve but other factors like time spend in the hospital, symptoms and mechanical ventilation rates never had any positive change. It has been found to bring with it adverse side effects like vomiting, hypokalemia, headaches and even death. Care should be taken when using Methylxanthines and close monitoring should be done on serum levels to avoid any serious complications.
Magnesium Sulfate
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