Respiratory Conditions Update: Restrictive Lung Disease.

Restrictive lung diseases are a heterogeneous group of conditions characterized by a restrictive pattern on spirometry and confirmed by a reduction in total lung volume. Patients with more severe symptoms may have a reduced diffusing capacity of the lung for carbon monoxide. Etiologies can be intrinsic with lung parenchymal involvement, as in interstitial lung diseases, or extrinsic to the lung, as in obesity and neuromuscular disorders. Idiopathic pulmonary fibrosis is a chronic progressive interstitial pneumonia with fibrosis for which treatment is primarily supportive with oxygen therapy, pulmonary rehabilitation, and management of comorbid conditions. Newer drugs for idiopathic pulmonary fibrosis, such as pirfenidone and nintedanib, can slow disease progression. Referral for evaluation for lung transplantation is recommended for appropriate patients. Obstructive sleep apnea and obesity hypoventilation syndrome increasingly are common health issues, with symptoms that can include snoring, daytime somnolence, difficulty concentrating, fatigue, witnessed apneas, and morning headaches. Serum bicarbonate may serve as a biomarker in screening for subclinical obesity hypoventilation syndrome. Preoperative evaluations should assess pulmonary risk in addition to cardiac risk with a thorough history, laboratory tests, and functional capacity assessments. Optimization of management may include weight loss, pulmonary rehabilitation, oxygen therapy, and respiratory support.