History

Fact Explanation
Cough Dry and unproductive nocturnal cough is characteristic of bronchial asthma. [1,3]
Wheezing Wheezing is a common presentation of asthma. The quality of life and sleep should be assessed in patients because nocturnal exacerbation are common in asthma. [1,3]
Chest tightness Chest tightness is another presentation of asthma. [4]
History of bronchial asthma Most of the pregnant ladies have a history of bronchial asthma. However some females may be diagnosed at the time of the pregnancy. [1]
References
  1. SCHATZ MICHAEL, DOMBROWSKI MITCHELL P.. Asthma in Pregnancy. N Engl J Med [online] 2009 April, 360(18):1862-1869 [viewed 19 August 2014] Available from: doi:10.1056/NEJMcp0809942
  2. HICKEY MARY T.. Asthma in Pregnancy. Journal of Obstetric, Gynecologic, & Neonatal Nursing [online] December, 41(s1):S171-S172 [viewed 19 August 2014] Available from: doi:10.1111/j.1552-6909.2012.01363_16.x
  3. SAXENA TARUN, SAXENA MANJARI. The effect of various breathing exercises (pranayama) in patients with bronchial asthma of mild to moderate severity. Int J Yoga [online] 2009 December [viewed 19 August 2014] Available from: doi:10.4103/0973-6131.53838
  4. IRWIN RS. Chest tightness variant asthma (CTVA): reconfirmed and not generally appreciated J Thorac Dis [online] 2014 May, 6(5):405-406 [viewed 19 August 2014] Available from: doi:10.3978/j.issn.2072-1439.2014.02.05

Examination

Fact Explanation
Tachypnea Patients with acute exacerbations are tachypneic and may avoid speaking and lying down due to tachypnea. [2]
Use of accessory muscles of respiration Increased airway resistance increases the work load of breathing, so accessory muscles of respiration are used as evidenced by suprasternal, substernal and intercostal recessions.
Tracheal tug Tracheal tug is present due to hyperinflation of the lungs. [2]
Wheezing [1] Wheezing is produced by airway hyperreactivity and bronchospasm. Silent chest is indicative of severe asthma, as there is no airflow to produce breath sounds. [2]
Pulse Patients with acute exacerbation of asthma have tachycardia and it indicates severity of asthma. Severe exacerbation causes pulsus paradox. [2]
Cyanosis Patients can develop peripheral cyanosis which might progress to central cyanosis if not treated. [2]
Altered consciousness Patients develop altered level of consciousness with severe asthma and it is considered a premorbid sign. [2]
References
  1. SCHATZ MICHAEL, DOMBROWSKI MITCHELL P.. Asthma in Pregnancy. N Engl J Med [online] 2009 April, 360(18):1862-1869 [viewed 19 August 2014] Available from: doi:10.1056/NEJMcp0809942
  2. ALDINGTON S, BEASLEY R. Asthma exacerbations ? 5: Assessment and management of severe asthma in adults in hospital Thorax [online] 2007 May, 62(5):447-458 [viewed 19 August 2014] Available from: doi:10.1136/thx.2005.045203

Differential Diagnoses

Fact Explanation
Dyspnea of pregnancy Dyspnea is a common complain during pregnancy affecting about 75% of pregnant ladies. Absence of cough, wheezing and chest pain is characteristic. [1,2,3]
Bronchitis [1] Acute bronchitis refers to inflammation of the large airways which is often self-limiting. Cough is the commonest presentation and it lasts for more than 5 days. [4]
Laryngeal dysfunction [1] Inappropriate vocal cord movements causes airway obstruction and respiratory distress. [5]
Hyperventilation syndrome [1] Patients with hyperventilation syndrome complain of chest pain. Reassurance is usually adequate for treatment. [6]
Pulmonary edema [1] Pulmonary edema is another cause for shortness of breath, chest pain and orthopnea.
Pulmonary embolism [1] Patients with pulmonary embolism present with sudden tightening chest pain, cough and hemoptysis.
Peripartum cardiomyopathy Peripartum cardiomyopathy presents with shortness of breath during the last month of pregnancy and during the first month of postpartum period. [3]
References
  1. SCHATZ MICHAEL, DOMBROWSKI MITCHELL P.. Asthma in Pregnancy. N Engl J Med [online] 2009 April, 360(18):1862-1869 [viewed 19 August 2014] Available from: doi:10.1056/NEJMcp0809942
  2. NELSON-PIERCY C. Respiratory diseases in pregnancy bullet 1: Asthma in pregnancy. [online] 2001 April, 56(4):325-328 [viewed 19 August 2014] Available from: doi:10.1136/thorax.56.4.325
  3. PERKINS D. A., NIELSEN C., FAULX M.. A young pregnant woman with shortness of breath. Cleveland Clinic Journal of Medicine [online] 2008 November, 75(11):788-792 [viewed 19 August 2014] Available from: doi:10.3949/ccjm.75.11.788
  4. WENZEL RICHARD P., FOWLER ALPHA A.. Acute Bronchitis. N Engl J Med [online] 2006 November, 355(20):2125-2130 [viewed 19 August 2014] Available from: doi:10.1056/NEJMcp061493
  5. DECKERT J, DECKERT L. Vocal cord dysfunction. Am Fam Physician [online] 2010 Jan 15, 81(2):156-9 [viewed 19 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/20082511
  6. MAGARIAN GJ, MIDDAUGH DA, LINZ DH. Hyperventilation syndrome: a diagnosis begging for recognition. West J Med [online] 1983 May, 138(5):733-736 [viewed 19 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1010816

Investigations - for Diagnosis

Fact Explanation
Spirometry Reduced FEV1 or 12% or greater improvement in FEV1 after inhalation of a beta agonist (albuterol) can be used to diagnose bronchial asthma. [1]
Peak flow meter Peak flow meter measures the airflow through the bronchi so it indicates the degree of airway obstruction. During acute exacerbation peak expiratory flow rate is decreased. [2]
References
  1. SCHATZ MICHAEL, DOMBROWSKI MITCHELL P.. Asthma in Pregnancy. N Engl J Med [online] 2009 April, 360(18):1862-1869 [viewed 19 August 2014] Available from: doi:10.1056/NEJMcp0809942
  2. BRUSASCO V. Usefulness of peak expiratory flow measurements: is it just a matter of instrument accuracy?. [online] 2003 May, 58(5):375-376 [viewed 20 August 2014] Available from: doi:10.1136/thorax.58.5.375

Investigations - Followup

Fact Explanation
Pulse oximetry Continuous monitoring of oxygen saturation is indicated and oxygen saturation should be maintained at 95% or more. [1]
Monitoring of fetal well being Fetal ultrasound scan is necessary for evaluation of fetal well being. Fetal movements, liquor volume and growth parameters are being assessed. Cardiotocogram is helpful in detecting fetal cardiac activity. [1,2]
Methacholine testing Females who are diagnosed to have bronchial asthma during pregnancy should undergo methacholine testing during the postpartum period. This test demonstrates airway hyperreactivity and it is not indicated during the period of pregnancy. [1]
References
  1. SCHATZ MICHAEL, DOMBROWSKI MITCHELL P.. Asthma in Pregnancy. N Engl J Med [online] 2009 April, 360(18):1862-1869 [viewed 19 August 2014] Available from: doi:10.1056/NEJMcp0809942
  2. HICKEY MARY T.. Asthma in Pregnancy. Journal of Obstetric, Gynecologic, & Neonatal Nursing [online] December, 41(s1):S171-S172 [viewed 19 August 2014] Available from: doi:10.1111/j.1552-6909.2012.01363_16.x

Management - General Measures

Fact Explanation
Health education Females with asthma are at increased risk of preeclampsia, preterm birth, low birth weight, intrauterine growth retardation, and congenital malformations of the infant and perinatal death. However better symptom control is associated with good outcome. Hence patients should be advised to be compliant with treatment. Patients should be educated about the inhaler technique. avoidance of triggers should be done always if possible. Smoking both active and passive should be quit. [1,2,3]
References
  1. SCHATZ MICHAEL, DOMBROWSKI MITCHELL P.. Asthma in Pregnancy. N Engl J Med [online] 2009 April, 360(18):1862-1869 [viewed 19 August 2014] Available from: doi:10.1056/NEJMcp0809942
  2. HICKEY MARY T.. Asthma in Pregnancy. Journal of Obstetric, Gynecologic, & Neonatal Nursing [online] December, 41(s1):S171-S172 [viewed 19 August 2014] Available from: doi:10.1111/j.1552-6909.2012.01363_16.x
  3. NELSON-PIERCY C. Respiratory diseases in pregnancy bullet 1: Asthma in pregnancy. [online] 2001 April, 56(4):325-328 [viewed 19 August 2014] Available from: doi:10.1136/thorax.56.4.325

Management - Specific Treatments

Fact Explanation
Inhaled oxygen Oxygen should be administered in almost all the patients with acute exacerbation of asthma. [3]
Corticosteroids Inhaled corticosteroids is the most effective controller medication used. If the disease is not controlled with inhaled corticosteroids alone, add-on therapy with long-acting β-agonists, leukotriene-receptor antagonists or theophylline is indicated. Oral corticosteroids can be used in severe cases. Systemic corticosteroids is administered via an intravenous line during an acute exacerbation of asthma. Patients who require high doses of inhaled corticosteroids can be treated with fluticasone. [1,2,3]
β-agonists Inhaled short acting β-agonists are used as relievers, as this provides a symptomatic relief during an acute exacerbation. Long acting β-agonists are used as preventers. Intravenous β2 agonists are indicated in the management of acute exacerbation refractory to inhalation therapy. [1,2,3]
Inhaled anticholinergic drugs Combination of inhaled β-agonists and anticholinergic drugs(ipratropium) are used in the treatment of acute exacerbation of asthma. [3]
Leukotrine modifiers Although its safety during pregnancy is doubtful, leukotrine modifiers are recommended to be continued in patients with resistant asthma who showed significant response to leukotrine modifiers. [1,2,3]
Intravenous aminophylline Intravenous aminophylline is used in emergency situations where inhalation therapy fails. [3]
References
  1. SCHATZ MICHAEL, DOMBROWSKI MITCHELL P.. Asthma in Pregnancy. N Engl J Med [online] 2009 April, 360(18):1862-1869 [viewed 19 August 2014] Available from: doi:10.1056/NEJMcp0809942
  2. HICKEY MARY T.. Asthma in Pregnancy. Journal of Obstetric, Gynecologic, & Neonatal Nursing [online] December, 41(s1):S171-S172 [viewed 19 August 2014] Available from: doi:10.1111/j.1552-6909.2012.01363_16.x
  3. NELSON-PIERCY C. Respiratory diseases in pregnancy bullet 1: Asthma in pregnancy. [online] 2001 April, 56(4):325-328 [viewed 19 August 2014] Available from: doi:10.1136/thorax.56.4.325