Kyphoscoliosis is the most common and best understood chest wall disease, is used here as a prototype for discussing the natural history, pathophysiology, and management of all of these disorders.
Kyphoscoliosis is a disorder characterized by posterior curvature (kyphosis) and lateral curvature (scoliosis) of the spine. These processes alone and in combination decrease the volume and mobility of the lung and chest wall.
(i) Kyphoscoliosis is a common skeletal abnormality that affects 1% of the United States population and occurs predominantly in females. The prevalence of clinically significant deformity (i.e., an angle of greater than 10°) is 23 in 1000 individuals.
(ii) The etiology of kyphoscoliosis is not clear in 80% of cases. A major known cause is childhood poliomyelitis. Congenital abnormalities with or without bone defects are uncommon.
(i) Derangement of lung function in kyphoscoliosis predominantly results from reduced lung volume, which is caused by stiffness of the chest wall (reduced compliance) and reduction of FRC. The pressure-volume curve of the lung is nearly normal, but the chest wall is displaced downward and to the right, thus decreasing total respiratory compliance. Forced expiratory flow is preserved relative to lung volume.
(ii) Gas exchange usually is preserved until alveolar hypoventilation occurs. Mild widening of the alveolar-arterial PO2 gradient is seen and is the result of ventilation-perfusion inequality due to the compressive effect of atelectasis and inadequate periodic hyperinflation.
(iii) Pulmonary hypertension eventually is present at rest as well as during exercise with moderate chest wall deformity and in the absence of clinical signs of cardiac dysfunction.
(i) Exertional dyspnea is the outstanding respiratory symptom of kyphoscoliosis. The onset and severity of dyspnea correlate with the degree of the spinal angulation.
(a) Patients with a deformity of less than 70° have no respiratory symptoms.
(b) Patients whose deformity exceeds 70° have a risk of becoming symptomatic.
(c) Dyspnea is the rule in patients with a deformity of more than 100°, and hypoventilation supervenes in those whose deformity exceeds 120°.
(ii) Bronchitic symptoms are unusual in the absence of chronic bronchitis or atelectasis.
(iii) Sequelae of prolonged arterial hypoxia may develop, including pulmonary hypertension, right ventricular dysfunction, and cor pulmonale. These are late manifestations.
The degree of kyphoscoliosis is determined by measuring the angle formed by converging line segments drawn on the upper and lower limbs of the primary curves. Ribs on the convex portion of the spine are widely spaced and rotated posteriorly, causing a characteristic hump. Ribs on the concave aspect are crowded and displaced anteriorly and encroach on the apex of the secondary curve.
Early identification of kyphoscoliosis in adolescence is the key to prevention of symptomatic disease. Therapeutic intervention is considered in cases in which the angulation is greater than 40°. There are two forms of intervention.
(i) A mechanical device (e.g., the Milwaukee brace) can be applied externally during the early stages of the disease.
(ii) An operative procedure (e.g., the Harrington procedure) can be performed using metallic rods and focal spinal fusion, after which the patient wears a plaster-of-Paris jacket cast for several months. Surgery does not improve the maximal breathing capacity but may improve arterial oxygen and oxygen desaturation. At best, surgery appears to preserve whatever pulmonary function is present at the time of intervention.
Respiratory failure and cor pulmonale are the major complications of kyphoscoliosis. These conditions result from respiratory infection and ventilatory suppression by uncontrolled oxygen therapy and sedatives. Periodic hyperinflation with positive or negative pressure devices appears to increase lung compliance and PO2 in outpatients.
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Note: Must consult your doctor for more information and proper treatment for the above described disease.
|Chronic Obstructive Pulmonary Disease|
|♦||Acute Respiratory Failure|
|♦||Adult Respiratory Distress Syndrome|
|♦||Pulmonary Embolism Disease|
|♦||Diseases of the Pleura|
|♦||Pulmonary Neoplasms/Lung Cancer|
|♦||Chest Wall Disorders|
|♦||Diffuse Interstitial Lung Disease|
|♦||Occupational Lung Disease|
|♦||Pulmonary Diseases of Unknown Etiology|
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