Dyspnea

DYSPNEA

DR. SIDDHARTH – MED PG

DEFINITION Dyspnea is defined as difficult or labored

breathing or the unpleasant awareness of ones breathing.

The American Thoracic Society defines dyspnea as a “subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity.

MECHANISM Respiratory sensations are the

consequence of interactions between the efferent i.e. the motor output from the brain to the ventilatory muscles and the afferent i.e. sensory input from receptors throughout the body (feedback) which are integrated in the brain.

ASSOCIATION OF QUALITATIVE DESCRIPTORS & MECHANISMS

ACUTE DYSPNEA

Acute pulmonary edema Pneumothorax Pulmonary embolism Pneumonia Airway obstruction

CHRONIC DYSPNEA Heart failure Pulmonary disease Anxiety Obesity Poor physical fitness Pleural effusion Asthma

RESPIRATORY CAUSES OF DYSPNEA

Diseases of the airway - COPD & ASTHMA

Diseases of the chest wall – Kyphoscoliosis, weakness of vent muscles such as myasthenia gravis, GBS.

Diseases of the lung parenchyma – Autoimmune disorders, ILD, Infections, Occupational exposure

CARDIOVASCULAR CAUSES Diseases of the left heart – Diseases of

myocardium resulting from CAD, Non ischemic cardiomyopathy.

Diseases of the pulmonary vasculature - Pulmonary thromboembolism, Pulmonary hypertension, Pulmonary vasculitis.

Diseases of the pericardium – Constrictive pericarditis, cardiac tamponade.

OTHER CAUSES Mild to moderate anemia Obesity due to: a. Decreased compliance of the chest wall. b. Cardiovascular deconditioning (poor fitness) Dyspnea that is medically unexplained

has been associated with increased sensitivity to the unpleasantness of acute hypercapnia.

DYSPNEA SUGGESTING PULMONARY CAUSE Cough with expectoration Wheezing No relation to exertion Fever Pleuritic chest pain Loss of wt. Progressive over many years Prompt response to Oxygen and bronchodilators Seasonal variation

DYSPNEA SUGGESTIVE OF CARDIAC CAUSE

PND and orthopnea Associated with symptoms of heart

disease Expectorant pink frothy sputum Rapid progression Response to diuretics and digoxin

PND PND is the occurrence of dyspnea during sleep

Typically, a patient is woken up few hours into sleep with transient acute pulmonary edema.

In contrast to orthopnea it can last up to half an hour or so.

PND is relieved by assuming upright position

MECHANISM Absorption of edema fluid with increase in Rt

ventricular output causing over filling the lungs

Diminished sympathetic drive of sleep, decreasing LV contractility

Nocturnal arrhythmia

Sleep apnea

ORTHOPNEA It refers to dyspnea on supine position

It results from increase in hydrostatic pressure in lung that occurs in assumption of supine position.

Sitting up leads to rapid relief of symptom.

It is related to increase in venous return to the heart in supine position.

Increase in venous return which can not be handled by failing left ventricle.

It is a sign of LV dysfunction

It is associated with cough which is called as nocturnal cough.

The transient rise in left ventricular pressure results in transient lung stiffness and consequent cough.

The severity can be graded by the number of pillow used at night, ex. Three pillow orthopnea

It can also be seen in COPD and condition with large ascites.

CAUSES Left heart failure COPD Constrictive pericarditis Severe ascites B/L Diaphragmatic paralysis

MS Dyspnea is the initial presenting symptom

of MS It occurs from beginning of disease due to

Pulmonary venous hypertension Unlike aortic stenosis patient with MS with

onset of dyspnea live beyond 5 years. It has prognostic importance in MS NYHA functional class I has 10 years

survival of 85% and class III of 20%

AS Angina, syncope and dyspnea are the three

cardinal symptom of AS Dyspnea is late in onset cause of PVH occurring

after onset of LV dysfunction After onset of dyspnea the avg survival is 1.5 years Causes of dyspnea in mild AS: a. Associated mitral valve disease b. Hypertrophic Cardiomyopathy c. CAD d. Unrelated pulmonary disorder

MR Palpitation is first symptom in MR and dyspnea

follows Unlike MS, dyspnea occurs only after onset LV failure Severe MR in non compliant LA Associated MS Rapid progression of dyspnea in MR: Infective endocarditis Recurrence of rheumatic activity Chordal rupture onset of AF CAD

AR Dyspnea occurs late in course of AR with

onset of LV failure Early onset of dyspnea indicate

associated mitral valve disease or acute AR

It is late to appear and progresses slowly Dyspnea class II,III,IV should be consider

as indication of surgery

CYANOSIS It refers to blush discoloration of skin

and mucous membrane resulting from an increased quantity of reduced hemoglobin (deoxy Hb) or of hemoglobin derivatives. ( eg: Methemoglobin/sulfhemoglobin )

TYPES

PERIPHERAL CYANOSIS Peripheral cyanosis occurs due to slowing of

blood flow. Arterial blood is normally saturated. It results from vasoconstriction and diminished

peripheral blood flow such as 1. Cold exposure 2. Shock 3. Congestive heart failure 4. Arterial obstruction- embolus/PVD 5. Venous obstruction-

Thrombophlebitis/DVT

CENTRAL CYANOSIS Its due to reduced SaO2 in blood or due to an

abnormal Hb derivative. Causes: 1. Decreased atm Hg- high altitude 2. Impaired pulmonary function a. Alveolar hypoventilation- Ext pneumonia

pulmonary edema Emphysema b. Ventilation – perfusion mismatch c. Impaired oxygen diffusion

3. Anatomic shunts a. Cyanotic congenital heart disease b. pulmonary atreriovenous fistula c. Multiple small intrapulmonary

shunts 4. Hb abnormalities: a. Methemoglobinemia b. Sulfhemoglobinemia c. Carboxyhemoglobinemia

THANK U