Carbon monoxide diffusing capacity

Chest constriction impaired carbon monoxide diffusion capacity decrease in lung function without exercise... 

Changes in pulmonary function have been observed in a variety of species after short-term exposure to ozone, including alterations in the elastic behavior of the lungs, increased resistance to flow, and decreased carbon monoxide diffusion capacity. 

A short-term study of guinea pigs exposed to zinc oxide fume 3 hours/day for 6 days at the threshold limit value (TLV) of 5mg/m revealed pulmonary function changes and morphologic evidence of small airway inflammation and edema. Pulmonary flow resistance increased, compliance decreased, and lung volumes and carbon monoxide diffusing capacity decreased. Some of these changes persisted for the 72-hour duration of postexposure follow-up. 

A 77-year-old man who had taken amiodarone 400 mg/day for 11 months developed crackles at the lung bases and scattered respiratory wheeze (76). His leukocyte count was raised at 13.5 x 109/1 and he had progressive reduction in carbon monoxide diffusing capacity, serially measured. A chest X-ray showed bilateral opacities in the upper zones, peripheral in distribution, and a CT scan showed dense bilateral lung parenchjmal opacities. The symptoms of dyspnea on exertion, cough with minimal sputum, pleuritic chest pain, and low-grade fever abated after withdrawal, and the upper lobe densities resolved. 

In 25 patients, three had proven interstitial pneumonitis and KL-6 serum concentrations of 414, 848, and 1217 U/ ml in contrast, all of the other 22 patients had normal CT scans and normal KL-6 concentrations (under 500 U/ml) (82). In the same study the limitations of carbon monoxide diffusing capacity in the diagnosis of amiodarone-induced lung disease (SEDA-15, 168) were again demonstrated. 

Beryllium compromises the immune system. Enzymes catalyzed by magnesium or calcium can be inhibited by beryllium succinic dehydrogenase is activated. Beryllium exposure leads to a deficiency in lung carbon monoxide diffusing capacity. Hypercalcemia (excess of calcium in the blood) can occur. 

Diffusion Carbon monoxide diffusing capacity Measurement of efficiency of alveolar gas exchange decreases with thickening of alveolar blood-air barrier... 

The majority of patients with pulmonary hypertension are largely asymptomatic until marked vascular alterations have developed. When blood flow through the pulmonary artery is obstructed over a long period of time, however, the clinical picture is predictable and markedly uniform. In general, the patients exhibit normal pulmonary function measurements, a low carbon monoxide diffusion capacity (DlCO), and marked hyperventilation that leads to hypocapnia and decreased serum bicarbonate concentrations. Additional symptoms include weakness, fatigue, exertional dyspnea, and chest pains upon exertion due to low cardiac output and hypoxemia. Occasionally, hoarseness, hemoptysis, and cyanosis occur. 

Several animal inhalation toxicity studies have been conducted on various jet fuels (summarized in Table 4-2). In one study, male F344 rats were exposed to shale-oil-derived JP-4 continuously for 90 days by inhalation at 1,000 mg/m3. The exposure resulted in no effects on lung volumes, dynamic resistance and compliance, quasistatic compliance, partial and full forced vital capacities, carbon monoxide diffusion capacity, and closing volume. There... 

American Association for Respiratory Care, 1999, Clinical Practice Guideline Single-breath Carbon Monoxide Diffusing Capacity, Respir. Care, 44(5) 539-546. 

American Thmacic Society, 1995, Single Breath Carbon Monoxide Diffusing Capacity (transfer factor), Am. Rev. Respir. Dis., 152 2185-2198. 

Inhaled insulin In 251 patients with type 1 diabetes who used insulin lispro and insulin glargine, compared with 249 patients using AIR inhaled insulin and insulin glargine in a 6-month randomized trial, nocturnal hypoglycemia was more frequent in those who used AIR insulin, especially in the first month [12 ]. Those who used AIR insulin also had more frequent cough (28 patients compared with 14), dyspnea (5 patients compared with 0), and reduced carbon monoxide diffusing capacity in the lungs. More of those who used insulin lispro completed the study (217 versus 192). 

In patients with type 2 diabetes, in whom AIR insulin with meals n = 221) was compared with insulin glargine alone (n = 223) or AIR insulin in combination with insulin glargine (n = 115) for 52 weeks, there was also a reduction in carbon monoxide diffusing capacity of the lungs in those who used AIR insulin [13 =]. 

Pulmonary function tests reveal a restrictive pattern in early disease. In the acute phase, a reduction in lung volume, carbon monoxide diffusing capacity, and static lung compliance are common. Some patients also show evidence of small airway obstruction. 

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