eMedicine Specialties > Pulmonology > Obstructive Airways Diseases
Status Asthmaticus
Updated: Jun 4, 2009
Introduction
Background
Status asthmaticus is a medical emergency in which asthma symptoms are refractory to initial bronchodilator therapy in the emergency department. Patients report chest tightness, rapidly progressive shortness of breath, dry cough, and wheezing. Typically, patients present a few days after the onset of a viral respiratory illness, following exposure to a potent allergen or irritant, or after exercise in a cold environment. Frequently, patients have underused or have been underprescribed anti-inflammatory therapy. Illicit drug use may play a role in poor adherence to anti-inflammatory therapy. Patients may have increased their beta-agonist intake (either inhaled or nebulized) to as often as every few minutes. Also see Asthma.
Pathophysiology
Inflammation in asthma is characterized by an influx of eosinophils during the early-phase reaction and a mixed cellular infiltrate composed of eosinophils, mast cells, lymphocytes, and neutrophils during the late-phase (or chronic) reaction. The simple explanation for allergic inflammation in asthma begins with the development of a predominantly helper T2 lymphocyte–driven, as opposed to helper T1 lymphocyte–driven, immune milieu, perhaps caused by certain types of immune stimulation early in life. This is followed by allergen exposure in a genetically susceptible individual.
Specific allergen exposure (eg, dust mites) under the influence of helper T2 lymphocytes leads to B-lymphocyte elaboration of immunoglobulin E (IgE) antibodies specific to that allergen. The IgE antibody attaches to surface receptors on airway mucosal mast cells. One important question is whether atopic individuals with asthma, in contrast to atopic persons without asthma, have a defect in mucosal integrity that makes them susceptible to penetration of allergens into the mucosa.
Subsequent specific allergen exposure leads to cross-bridging of IgE molecules and activation of mast cells, with elaboration and release of a vast array of mediators. These mediators include histamine; leukotrienes C4, D4, and E4; and a host of cytokines. Together, these mediators cause bronchial smooth muscle constriction, vascular leakage, inflammatory cell recruitment (with further mediator release), and mucous gland secretion. These processes lead to airway obstruction by constriction of the smooth muscles, edema of the airways, influx of inflammatory cells, and formation of intraluminal mucus. In addition, ongoing airway inflammation is thought to cause the airway hyperreactivity characteristic of asthma. The more severe the airway obstruction, the more likely ventilation-perfusion mismatching will result in impaired gas exchange and hypoxemia.
Frequency
United States
The prevalence and severity of asthma cases are on the rise (see Asthma). Also increasing are the occurrences of asthma hospitalization and mortality resulting from status asthmaticus. Status asthmaticus is usually more common among persons in low socioeconomic groups, regardless of race, and particularly in people who live alone.
A 2004 study conducted at the Columbia University Medical Center,1 however, noted the number of patients with status asthmaticus requiring intensive care admissions declined over the past 10 years. The trend was toward less advanced presentations. This may reflect improvements in medication compliance, education, or access to medical care.
International
Similar to the US data, asthma mortality rates are increasing.
Mortality/Morbidity
- Patients who delay medical treatment, particularly treatment with systemic steroids, have a greater chance of dying.
- Patients with other preexisting conditions (eg, restrictive lung disease, congestive heart failure, chest deformities) are at particular risk of death from status asthmaticus.
- Patients who smoke regularly have chronic inflammation of the small airways and are at particular risk of death from status asthmaticus.
Race
- A 1997 study by Hanania et al2 noted that although asthma is more common among African American and Hispanic persons, this prevalence may be the result of socioeconomic factors rather than race.
- African American and Hispanic persons in the United States, in association with lower socioeconomic factors, have less access to regular specialist medical care, which leads to an increased risk of status asthmaticus.
- In the United States, particularly in large cities, illiteracy and lower educational competence are more prevalent in African American and Hispanic families, and children in these families have increased morbidity from asthma.
Sex
- Status asthmaticus is slightly more common in males than in females.
Age
- Status asthmaticus can occur in persons of any age group, including infants and geriatric patients. Mortality rates are higher in very young children and elderly adults.
- Children younger than 2 years, and sometimes those older, may have respiratory syncytial virus (RSV) infections that can result in severe attacks of wheezing that mimic status asthmaticus. Also, RSV infections can predispose patients to asthma later in life.
Clinical
History
- Patients with status asthmaticus have severe dyspnea that has developed over hours to days.
- Frequently, patients have a prior history of endotracheal intubation and mechanical ventilation, frequent emergency department visits, and previous use of systemic corticosteroids.
- Patients usually present with audible wheezing.
Physical
- Patients are usually tachypneic upon examination and, in early stages of status asthmaticus, may have significant wheezing. Initially, wheezing is heard only during expiration, but, later, wheezing occurs during both expiration and inspiration.
- The chest is hyperexpanded, and accessory muscles, particularly the sternocleidomastoid, scalene, and intercostal muscles, are used. Later, as bronchoconstriction worsens, patients' wheezing may disappear, which may indicate severe airflow obstruction.
- Normally, the pulsus paradoxus (ie, the difference in systolic blood pressure between inspiration and expiration) does not exceed 15 mm Hg. In patients with severe asthma, a pulsus paradoxus of greater than 25 mm Hg usually indicates severe airway obstruction.
Causes
- In persons with acute asthma, bronchospasms occur as a result of one or more inciting factors that may include, but are not limited to, a viral upper or lower respiratory tract infection, significant allergic response to an allergen (eg, pollen, mold, animal dander, house dust mites), exposure to an irritant, or vigorous exercise in a cold environment.
- Precipitating factors can include infection, allergen or irritant exposure, poor adherence to the medical regimen, strenuous exercise, and a rapid decrease in long-term oral steroid therapy.
- Inflammation can be the result of infection; lymphocyte, mast cell, eosinophilic, and neutrophilic responses; and airway epithelial damage. In addition, elevated plasma lactate levels were noted in patients with this condition in the first hours of inhaled beta-agonist treatment.3 The presence of a previous hyperadrenergic state may predispose to the development of this condition. This may also correlate with improvements in lung function.
More on Status Asthmaticus |
Overview: Status Asthmaticus |
| Differential Diagnoses & Workup: Status Asthmaticus |
| Treatment & Medication: Status Asthmaticus |
| Follow-up: Status Asthmaticus |
| References |
| Further Reading |
| Next Page » |
References
Han P, Cole RP. Evolving differences in the presentation of severe asthma requiring intensive care unit admission. Respiration. Sep-Oct 2004;71(5):458-62. [Medline].
Hanania NA, David-Wang A, Kesten S, Chapman KR. Factors associated with emergency department dependence of patients with asthma. Chest. Feb 1997;111(2):290-5. [Medline].
Rodrigo GJ, Rodrigo C. Elevated plasma lactate level associated with high dose inhaled albuterol therapy in acute severe asthma. Emerg Med J. Jun 2005;22(6):404-8. [Medline].
{Guideline} National Heart, Lung, and Blood Institute. Managing exacerbations of asthma. In: National Asthma Education and Prevention Program (NAEPP). Expert panel report 3: guidelines for the diagnosis and management of asthma. National Guideline Clearinghouse. Available at http://www.guideline.gov/summary/summary.aspx?doc_id=11678&nbr=006027&string=asthma. Accessed August 2008.
Spahn JD, Cherniack R, Paull K, Gelfand EW. Is forced expiratory volume in one second the best measure of severity in childhood asthma?. Am J Respir Crit Care Med. Apr 1 2004;169(7):784-6. [Medline].
Goldman MD, Carter R, Klein R, Fritz G, Carter B, Pachucki P. Within- and between-day variability of respiratory impedance, using impulse oscillometry in adolescent asthmatics. Pediatr Pulmonol. Oct 2002;34(4):312-9. [Medline].
Marotta A, Klinnert MD, Price MR, Larsen GL, Liu AH. Impulse oscillometry provides an effective measure of lung dysfunction in 4-year-old children at risk for persistent asthma. J Allergy Clin Immunol. Aug 2003;112(2):317-22. [Medline].
Ducharme FM, Davis GM. Measurement of respiratory resistance in the emergency department: feasibility in young children with acute asthma. Chest. Jun 1997;111(6):1519-25. [Medline].
Ducharme FM, Davis GM. Respiratory resistance in the emergency department: a reproducible and responsive measure of asthma severity. Chest. Jun 1998;113(6):1566-72. [Medline].
Skloot G, Goldman M, Fischler D, Goldman C, Schechter C, Levin S, et al. Respiratory symptoms and physiologic assessment of ironworkers at the World Trade Center disaster site. Chest. Apr 2004;125(4):1248-55. [Medline].
Saadeh CK, Goldman MD, Gaylor PB. Forced oscillation using impulse oscillometry (IOS) detects false negative spirometry in symptomatic patients with reactive airways. J Allergy Clin Immunol. 2003;111:S136.
Newman LJ, Richards W, Church JA. Isoetharine-isoproterenol: a comparison of effects in childhood status asthmaticus. Ann Allergy. Apr 1982;48(4):230-2. [Medline].
Haskell RJ, Wong BM, Hansen JE. A double-blind, randomized clinical trial of methylprednisolone in status asthmaticus. Arch Intern Med. Jul 1983;143(7):1324-7. [Medline].
Press S, Lipkind RS. A treatment protocol of the acute asthma patient in a pediatric emergency department. Clin Pediatr (Phila). Oct 1991;30(10):573-7. [Medline].
Heshmati F, Zeinali MB, Noroozinia H, Abbacivash R, Mahoori A. Use of ketamine in severe status asthmaticus in intensive care unit. Iran J Allergy Asthma Immunol. Dec 2003;2(4):175-80. [Medline].
Elliot S, Berridge JC, Mallick A. Use of the AnaConDa anaesthetic delivery system in ICU. Anaesthesia. Jul 2007;62(7):752-3. [Medline].
Burburan SM, Xisto DG, Rocco PR. Anaesthetic management in asthma. Minerva Anestesiol. Jun 2007;73(6):357-65. [Medline].
Rishani R, El-Khatib M, Mroueh S. Treatment of severe status asthmaticus with nitric oxide. Pediatr Pulmonol. Dec 1999;28(6):451-3. [Medline].
Mroueh S. Inhaled nitric oxide for acute asthma. J Pediatr. Jul 2006;149(1):145; author reply 145. [Medline].
Mikkelsen ME, Pugh ME, Hansen-Flaschen JH, Woo YJ, Sager JS. Emergency extracorporeal life support for asphyxic status asthmaticus. Respir Care. Nov 2007;52(11):1525-9. [Medline].
[Guideline] Dombrowski MP, Schatz M; ACOG Committee on Practice Bulletins-Obstetrics. ACOG practice bulletin: clinical management guidelines for obstetrician-gynecologists number 90, February 2008: asthma in pregnancy. Obstet Gynecol. Feb 2008;111(2 Pt 1):457-64. [Medline].
Schultz TE. Sevoflurane administration in status asthmaticus: a case report. AANA J. Feb 2005;73(1):35-6. [Medline].
Glover ML, Machado C, Totapally BR. Magnesium sulfate administered via continuous intravenous infusion in pediatric patients with refractory wheezing. J Crit Care. Dec 2002;17(4):255-8. [Medline].
Scarfone RJ, Loiselle JM, Joffe MD, Mull CC, Stiller S, Thompson K, et al. A randomized trial of magnesium in the emergency department treatment of children with asthma. Ann Emerg Med. Dec 2000;36(6):572-8. [Medline].
Bessmertny O, DiGregorio RV, Cohen H, Becker E, Looney D, Golden J, et al. A randomized clinical trial of nebulized magnesium sulfate in addition to albuterol in the treatment of acute mild-to-moderate asthma exacerbations in adults. Ann Emerg Med. Jun 2002;39(6):585-91. [Medline].
[Best Evidence] Blitz M, Blitz S, Beasely R, Diner BM, Hughes R, Knopp JA, et al. Inhaled magnesium sulfate in the treatment of acute asthma. Cochrane Database Syst Rev. Oct 19 2005;CD003898. [Medline].
Ram FS, Wellington S, Rowe BH, Wedzicha JA. Non-invasive positive pressure ventilation for treatment of respiratory failure due to severe acute exacerbations of asthma. Cochrane Database Syst Rev. Jan 25 2005;CD004360. [Medline].
Ueda T, Tabuena R, Matsumoto H, Takemura M, Niimi A, Chin K, et al. Successful weaning using noninvasive positive pressure ventilation in a patient with status asthmaticus. Intern Med. Nov 2004;43(11):1060-2. [Medline].
Leatherman JW, McArthur C, Shapiro RS. Effect of prolongation of expiratory time on dynamic hyperinflation in mechanically ventilated patients with severe asthma. Crit Care Med. Jul 2004;32(7):1542-5. [Medline].
Shiue ST, Gluck EH. The use of helium-oxygen mixtures in the support of patients with status asthmaticus and respiratory acidosis. J Asthma. 1989;26(3):177-80. [Medline].
Fuller CG, Schoettler JJ, Gilsanz V, Nelson MD Jr, Church JA, Richards W. Sinusitis in status asthmaticus. Clin Pediatr (Phila). Dec 1994;33(12):712-9. [Medline].
Sacha RF, Tremblay NF, Jacobs RL. Chronic cough, sinusitis, and hyperreactive airways in children: an often overlooked association. Ann Allergy. Mar 1985;54(3):195-8. [Medline].
Oguzulgen IK, Turktas H, Mullaoglu S, Ozkan S. What can predict the exacerbation severity in asthma?. Allergy Asthma Proc. May-Jun 2007;28(3):344-7. [Medline].
Ciccolella DE, Brennan K, Kelsen SG, Criner GJ. Dose-response characteristics of nebulized albuterol in the treatment of acutely ill, hospitalized asthmatics. J Asthma. Sep 1999;36(6):539-46. [Medline].
Mathison DA. Asthma in Adults, Evaluation and Management. In: Middleton E Jr, Reed CE, Ellis EF, Adkinson NF Jr, Yunginger JW, Busse WW, eds. Allergy Principles & Practice. 5th ed. St. Louis, Mo: Mosby-Year Book; 1998:901-20.
Patterson R, Grammar LC, Greenberger P, eds. Status Asthmaticus. In: Allergic Diseases: Diagnosis and Management. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:529-42.
Richards W. Hospitalization of children with status asthmaticus: a review. Pediatrics. Jul 1989;84(1):111-8. [Medline].
Schwartz HJ, Thompson JS, Sher TH, Ross RJ. Occult sinus abnormalities in the asthmatic patient. Arch Intern Med. Dec 1987;147(12):2194-6. [Medline].
Sthoeger ZM, Eliraz A, Asher I, Berkman N, Elbirt D. The beneficial effects of Xolair (omalizumab) as add-on therapy in patients with severe persistent asthma who are inadequately controlled despite best available treatment (GINA 2002 step IV)--the Israeli arm of the INNOVATE study. Isr Med Assoc J. Jun 2007;9(6):472-5. [Medline].
Further Reading
Asthma Resources from Medscape and eMedicine
Asthma News and Articles
Asthma Clinical Reference
Asthma CME
Keywords
status asthmaticus, asthma, asthma treatment, asthma children, acute asthma, hyperactive airway disease, asthma, asthma emergency, allergen exposure, respiratory tract infection, pollen, mold, animal dander, house dust mites, wheezing, chest tightness, progressive shortness of breath, dry cough, viral respiratory illness, underuse of anti-inflammatory therapy, allergic bronchopulmonary aspergillosis, Churg-Strauss vasculitis, beta-agonists, theophylline, bronchoconstrictive response, broncho-constrictive response, peripheral airway inflammation, bronchodilator therapy
Overview: Status Asthmaticus