6 Minute Walk Test.

 

Six minute walking Test

PKGhatak,MD

The six minute walk test (6MWT) is a useful tool for the evaluation of cardiac, pulmonary, and musculoskeletal systems. The test is low tech and requires practically no tools - an even surface long corridor, a pulse oximeter, a few chairs to sit along the path, a stopwatch and a distance measuring wheel, all that are needed. A 30 meter (100 feet) long corridor is ideal, but a shorter corridor also serves well.

Why do the 6MWT test.

In previous generations, the cardiopulmonary reserve was evaluated by a maximum voluntary ventilation test. This test was more suited for Olympic prospects or astronauts. The expired air had to be collected while exercising and analyzed for oxygen consumption. 6MWT test does not require any gas collection. It allows the patient to walk at his own pace, may stop, sit down and then can resume the test again. Only the distance walked in 6 minutes is recorded. Pulse oximetry is now quite familiar and popular for those who want to measure oxygen saturation in order to know when to go to a hospital if contacted covid. The patient may wear the smartwatch to detect the abnormal heart rhythm.

Cardiac stress test vs 6MWT.

6MWT is a safe initial method to evaluate cardiac and pulmonary status following an adverse coronary event or a respiratory disease. 6MWT does not replace cardiac tests, it is a useful supplement.

How 6MWT is performed.

No preparation is necessary. The patient should wear a pair of comfortable shoes, should continue to use oxygen, if on oxygen and use at the same flow rate. Use a cane or walker if used to. A 10 minute rest is required. Attach a pulse oximeter to a fingertip. Then start walking when a signal is given by the test supervisor. Continue to walk at the same pace, sit and rest on a chair on the way, if required, then resume walking again. When 6 minutes are up - stop walking. The supervisor marks the end distance and the test is complete.

Interpretation of 6MWT.

The formula for men.

A normal 6 minute walk distance (6MWD) = 1140 m(meter) – 5.61 x  BMI(body mass index) – 6.94 x age of the patient.

To obtain the lowest normal distance - subtract 153 m.

The formula for females.

6MWD = 1017 m – 6.24 x BMI – 5.83 x age.

To obtain the lowest normal distance - subtract 139 m.

The patients' results are given as the distance in meters and also as a percentage of the normal.

The initial results are then used to monitor the progression of the disease, improvement of therapy, alert possible arrhythmia potential, drop in oxygen saturation, hypotension, potential drop attacks, the onset of chest pain, etc.

Indication of 6MWT.

The ideal candidates for this test are -

1. Recent cardiac events, 2.Pulmonary atrial hypertension,3. Peripheral arterial disease, COPD in need of oxygen therapy.4. Frail patients suffering from chronic diseases requiring rehabilitation, 5. the elderly who want to live independently and 6. anyone else is starting cardiopulmonary rehab from the existing morbid condition.

What the test predicts.

The test indicates cardiac and pulmonary reserve capacities, response to therapy and long term prognosis of chronic illnesses.

What is the advantage of 6MWT.

6MWT is a simple but highly duplicate test. Situated for the elderly population suffering from Pulmonary arterial hypertension, peripheral arterial disease, or had an adverse cardiac event,

What are the contraindications.

The patient having unstable cardiac arrhythmia should not do this test. Those who have experienced cardiovascular collapse and the reason remained unexplained, and those in respiratory distress are not suitable for 6MWT.

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Hemoptysis

 

Hemoptysis

PKGhatak,MD

Hemoptysis was considered the confirmation of Consumption - a disease of the ancient world. Even if a patient was wasting away but did not have hemoptysis the condition was called by something else than consumption. This practice went on till Dr. Robert Koch discovered a bacterium and demonstrated conclusively that the bacteria was responsible for the disease called consumption. Later on, that bacteria were named Mycobacteria tuberculosis and the disease is known as pulmonary tuberculosis (TB). Hemoptysis continued to be the primary symptom of TB patients. The incidence of hemoptysis began to fall in 1945 with the introduction of Streptomycin and Para-amino salicylic acid (PAS). And subsequently, fell further in 1954 onwards with the use of Isoniazid and Ethambutol.

Hemoptysis is defined as coughing up any amount of blood, the quantity of blood is not included in the definition. Massive hemoptysis is defined as losing 200 ml or more of blood, between 5 and 200 ml of blood loss is considered moderate, and anything 5 ml or less is considered as minimal hemoptysis.

It should be kept in mind that the trachea, bronchus and all its branches are supplied by the arteries of the systemic circulation. And because the systemic circulation operates at high pressure, the blood loss becomes massive in a very short period of time, if a moderate sized vessel wall is breached.

In every case of hemoptysis, details should be taken about nose bleeds, use of anticoagulants (blood thinner), antiplatelet agents, and history of aspiration, and history of blood disorders.

Common Causes of hemoptysis.

Inflammation/ infection of the trachea and bronchial tree accounts for 25 % of hemoptysis, Carcinoma of lung and lung metastasis – 20%, Bronchiectasis - 10% Cardiovascular and Pulmonary emboli - 10 %, lung contusion from automobile accidents and other conditions -35 %.

Reported causes of Hemoptysis: -

Lung cancer, narcotizing pneumonia, cystic fibrosis, COPD, pulmonary emboli/infraction, lung abscess, bronchiectasis, TB, fungal infection, pneumonic plague, sinusitis, acute bronchitis, bronchovascular fistula, congestive heart failure, bleeding diathesis, arteriovenous malformation, hereditary hemorrhagic telangectasia, endometrial tissue metastasis in lungs, bronchlolithiasis, mitral stenosis, severe pulmonary hypertension, pulmonary edema, Wegener granuloma, microscopic polyangiitis, aspergilloma, foreign bodies, Goodpasture syndrome, cocaine other recreational drug use, bronchoscopic biopsy, trauma to chest wall causing bruised lungs from automobile accidents, Anticoagulant and antiplatelet therapy.

Presenting symptoms.

Patients often experience a sensation of heaviness in the chest and something gurgling inside the chest before they cough up blood. The blood brought up may contain gritty brocholiths, blood and pus in cases of lung abscess. Recurrent hemoptysis is usual in TB and bronchiectasis patients. Streaks of blood and rusty sputum are present in bacterial pneumonia cases.

Diagnosis and Treatment.

Like any emergency situation - triage, quick assessment, securing a patent airway and prevention of aspiration, positioning the patient in bed with the involved side down, reassurance and relieving fear, is followed by tests and imaging.

In the case of massive hemoptysis, the initial attempt is made to control bleeding. If the patient's history does not suggest blood disorder or coagulation/platelet dysfunction, then an immediate bronchoscopy with rigid and fiberoptic bronchoscope is performed under general anesthesia. Localizing the source of bleeding is essential. If the bleeding site is detected then the bleeding vessel is cauterized by laser or electro-cauterization or argon plasma coagulation. If the bleeding site is distal to the fiberoptic bronchoscope and the scope cannot be advanced further then tamponade is achieved by radiopaque surgical dressings or by a balloon catheter.

After controlling bleeding, an Angio-CT is obtained. If the bleeding vessel is identified then embolization of the vessel is carried out. If that fails, then surgical excision of the lesion or lobectomy is required.

In a previous generation, hemoptysis from cavitary TB was successfully controlled by therapeutic pneumothorax. In rural communities of some poor countries, this treatment is still carried out. The therapeutic pneumothorax for the treatment of pulmonary TB in the 1910s was advanced by Dr. Carlo Forlanini of Italy. For his efforts he was nominated for the Nobel Prize in Medicine 20 times between 1912 and 1932; his sponsors were not discouraged because Dr. Robert Koch was nominated for the Nobel Prize in Medicine 50 times before he was awarded the Nobel Prize in 1905.

In a patient who is not actively bleeding, a CT of the chest is performed in the hope that localizing the disease would be possible; often CT is negative. Fiberoptic bronchoscopy is performed to detect cancer or any source of bleeding.

In cases of minimal but recurrent bleeding, the bleeding usually stops after 6 months. These patients are followed for cancer surveillance.

Bleeding from pulmonary hypertension and mitral stenosis, congestive heart failure, pulmonary edema, infectious causes, etc. are treated medically and supplemented by surgery where applicable.

Embolization of arteriovenous malformation is useful therapy. Recurrence of pulmonary emboli is treated with anticoagulant. All other treatable medical conditions are appropriately treated. 

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Bronchiectasis

Bronchiectasis

PKGhatak,MD

Bronchitis is a permanent dilatation of a small segment of the bronchial tube that results from the destruction of walls of the bronchus from repeated inflammation or infection.

Bronchiectasis due to cystic fibrosis accounts for 50% of all cases of bronchiectasis. Congeal or acquired deficient mucociliary defense mechanism, ciliary dyskinesia, alpha 1 antitrypsin deficiency, congenital mitochondrial diseases, congenital or acquired Immunoglobulin diseases, immunocyte depression from immunotherapy, etc. favor repeated bacterial, fungal, mycobacterial infections, HIV infection and account for a few cases. Chronic lung diseases like pulmonary emphysema, silicosis, allergic aspergillosis, pulmonary tuberculous and foreign body bronchus, pulmonary fibrosis secondary to rheumatoid arthritis, Sjogren syndrome, SLE, Crohn's disease, etc. fill the rest of cases of bronchiectasis.

Childhood infection and Bronchiectasis.

Measles and whooping cough are dominant causes of bronchiectasis in poor countries, equally important, post bacterial pneumonia, specially due to Staphylococcus aureus, Hemophilus influenza and pulmonary tuberculosis.

Bronchiectasis is a small pouch, as the mucus accumulates in the pouch, the mucus remains at the site. It is a favorable medium for bacteria, fungus, or mycobacteria growth. Repeated and/persistent infections damage the structure of the bronchus, erode blood vessels causing hemoptysis, or ruptures into the pleural space and develop an open path to the pleural space and produce a bronchopleural fistula and which can easily lead to a purulent pleural effusion and pleural fibrosis.

Descriptive types.

About 50% of bronchiectasis are cylindrical types, 40% are cystic, 10% are beaded - (narrow segments of structurally normal bronchi are interspersed between rows of the dilated portions). 25% are of mixed types.

Presenting symptoms.

Cough productive of a large volume of purulent sputum; when allowed settling, separates in three distinct layers- bottom consists of necrotic cells and tissues, the middle layer contains clear fluid and the top layer contains foaming surface. The sputum has a sweet offensive odor. Fever, loss of weight, malnutrition, etc. are due to chronic wasting conditions, but hemoptysis occurs frequently, the volume of blood brought up is generally moderate quantity, and rarely massive hemoptysis can exsanguinate the patient.

Kartagener Syndrome.

Kartagener syndrome is one syndrome that all pulmonary physicians/ surgeons are familiar with. This condition is an autosomal recessive inherited disease. A patient presents with repeated sinusitis, bronchitis/pneumonia, hemoptysis, clubbing of fingers and toes and sterility in males. The defect is due to ciliary dyskinesia. Associated conditions are situs inversus of various degrees – from dextrocardia (heart and great vessels are on the right side) to a complete reversed position of all internal organs and the presence of bronchiectasis.

Diagnosis of Bronchiectasis.

A chest x-ray may or may not show any abnormality that is the specific radiological sign for bronchiectasis. CT of the chest, specially HTCT, shows the following signs – tram-lines (parallel lines with a clear central area), a bunch of grapes sign, signet ring sign, a string of pearl sign (narrow but intact bronchial segments in between small dilated bronchiectasis segments appear in a row). Location of positive radiological findings are in the - basal segments, right apical segments, left lingular segment and posterior upper middle segment.

Bronchoscopy.

All cases, at least initially, require bronchoscopic examination and are valuable to diagnose the presence of a foreign body bronchus, adenoma, carcinoma, or aspirated gastric contents and also to determine the degree of bronchiectasis involvement. Appropriate cultures, smears and cytology studies are routinely ordered.

Nowadays bronchograms are not performed. CT/ MRI eliminated that practice.

Pulmonary function impairment evaluations

Pulmonary function evaluations are carried out by PFT, oximetry, 6 mins walk tests and other appropriate tests to detect any and all underlying conditions that may lead to bronchiectasis.

Goal of treatment.

Depending on the underlying condition, the treatment and prognosis vary from one case to the other. A prompt and aggressive treatment protocol consists of proper antibiotic therapy, postural drainage of the retained bronchial secretion, chest percussion to help loosen thick sticky mucus, proper hydration of patients and the humidification of inhaled air.

Complications are minimized by antibiotic prophylaxis, bronchodilator drugs, mucolytic agents, appropriately administered pneumonia, influenza vaccines and surgical intervention when hemoptysis continues.

Surgery.

If the bronchiectasis is localized to one segment only, the lobectomy is only curative therapy, if the patient still has an adequate pulmonary reserve.

Bronchiectasis numbers are decreasing in developing countries because of good public health measures, childhood vaccination like MMR and adult vaccination programs and prompt medical attention to the needs of patients.

But the same cannot be said about poor countries and where people are forced to live in refugee camps.

Attempts should be made to limit the damage to the lungs by implementing good public health measures.

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