Abraham Chiu En LoongGroup 1
6th Year Therapy
2012
Difficulty in breathing or dyspnoea is described as the increased awareness of one’s laborious breathing. Difficulty in breathing is one of the commonest complaints a patient will present with, next to fever and upper respiratory tract infection. It may be a symptom in a varied range of pathological entities and in a similar range of varied body systems.
This is sometimes confused with asthma, where there is a component of difficulty breathing, but is associated with an expiratory wheeze. So with regards to the pathophysiology, symptoms, and management we will discuss on the similarities and the dissimilarities of bronchial asthma and cardiac asthma.
Bronchial asthma (BA) is a respiratory tract condition, where there is an element of chronic inflammatory process, with reversible narrowing of the airways and an associated airway hyper responsiveness. This is usually caused by immune mediated mechanisms and/or direct contact with minute particles. There are oedematous cells with, mucus plugs, secretion of mucus and thickened basement membranes.
Here on examination of the lungs the patient will have bilateral wheezing sounds/ rhonchi. The management of this condition is done through using oxygen and bronchodilators like beta agonists, with long term usage of corticosteroids to retard the chronic inflammatory process. If not properly managed there can be sudden death following life threatening asthma attacks or respiratory failure.
Cardiac asthma (CA) is a condition where there is either an acute left ventricular failure (left heart failure) or congestive (left and right) cardiac failure. In this condition, the hearts left side has become damaged leading to reduced capacity to pump the blood out of the heart. Thus, blood backtracks into the pulmonary veins, and the capillary baskets around the alveoli of the lungs. The hydrostatic pressure finally gives way to the transudation of fluids into the alveoli reducing the effective surface are for the diffusion of gases. This will lead to a feeling of drowning, where the patient complains of dyspnoea.
Here on examination of the lungs, there will be bilateral basal fine crepitations. The management will be based on oxygenation and reducing the fluids in the lungs with morphine, and reducing the overall load to the heart with the use of a loop diuretic like Furosemide, and controlling the blood pressure. Unless this is properly managed with the underlying condition, there is a risk of death due to repeated episodes or chronic heart failure.
The pattern of shortness of breath helps doctors determine which type of asthma you have — people with bronchial asthma tend to experience shortness of breath early in the morning, whereas people with heart failure and cardiac asthma often find they wake up breathless a few hours after going to bed, and have to sit upright to catch their breath. This is because in people with heart failure, lying down for prolonged periods will cause fluid to accumulate in the lungs leading to shortness of breath.
Both bronchial and cardiac asthma can make people short of breath when they exert themselves. In bronchial asthma, symptoms are usually brought on by vigorous exercise and tend to be worse after the exercise than during it. On the other hand, cardiac asthma tends to happen during less vigorous exertion — someone with heart failure can find themselves short of breath while climbing stairs, or in severe cases, while getting dressed.
Evidence Bronchial Asthma Cardiac asthma attack
Previous illnesses
Chronic bronchopulmonary disease, vasomotor rhinitis, allergic disease
Rheumatic heart disease, GB, CHD, chronic glomerulonephritis
The reason for the attack
Acute inflammation in the respiratory tract, the contact with the allergen, psychogenic factors, meteorological factors
The physical and mental stress, acute MI
The nature of the attack
Expiratory dyspnea Ispiratory dyspnea
The nature of cyanosis
Central Expressed acrocyanosis
Auscultation Abundant scattering dry whistling and buzzing mainly expiratory wheezing
Rales are mainly in the lower lung
Pulse Rapid, weak filling, the rhythm is correct
Often arrhythmic
Percussion heart size
Reduced Increased
Edema No Often there
Sputum Thick, viscous, separated with difficulty in small quantities
Liquid, frothy, sometimes pink, it separates
Size of the liver Not changed Often increased
Therapeutic effect
Of bronchodilators Of morphine, drainage, cardiac glycosides, diuretics
Diagnostic aid Bronchial asthma Cardiac asthma
Heart failureAbout the right-ventricular type
On the left-ventricular type
ECG changesSigns of right ventricular systolic overload
Signs of left ventricular systolic overload and myocardial ischemia
Character of sputum
Thick, viscous, separated with difficulty in small quantities
Large, liquid, sometimes foaming with blood
The nature of breathlessness
ExpiratoryInspiratory, then mixed
Orthopnea No There is
Auscultation Dry rales Bubbling rale
Chest X-rayEmphysematous, depletion of lung pattern
Signs of congestion