Diffusing capacity is not measurably affected by routine lung perfusion scanning.

Lung scanning with radiolabeled macroaggregated albumin (MAA) has caused cardiovascular collapse and death in patients with extensive pulmonary vascular disease. These adverse reactions have been suggested to be secondary to MAA embolic occlusion of a significant portion of the remaining pulmonary circulation. The single breath diffusing capacity for carbon monoxide (SBDLCO) is heavily dependent on the status of the pulmonary microcirculation and is reduced in clinical pulmonary embolism. The effect of MAA particles on the lung microcirculation was measured by SBDLCO in 11 patients undergoing clinically indicated lung perfusion scanning. SBDLCO was measured before and immediately after injection of 256,000 to 448,000 20-40 micron particles of [99mTc]MAA. Mean SBDLCO prior to injection was 18.9 +/- 1.7 (s.e.m.) and immediately after injection was unchanged at 19.0 +/- 1.6 ml/min/mmHg. The lowest pre-injection SBDLCO values were 11.5 and 6.2 ml/min/mmHg (54% and 28% of predicted, respectively); in neither of these patients was there a detectable change in SBDLCO measured after injection of MAA. Thus occlusion of as many as 448,000 20-40 micron pulmonary vessels by MAA is without detectable impact on the transfer of carbon monoxide even in patients with sufficient pulmonary disease to lower the SBDLCO to 28% of predicted.

[1]  H. Z. Bencowitz.  Single breath diffusing capacity in a representative sample of the population of Michigan, a large industrial state. , 1983, The American review of respiratory disease.

[2]  A. Sasahara,et al.  Effect of thrombolytic therapy on pulmonary-capillary blood volume in patients with pulmonary embolism. , 1980, The New England journal of medicine.

[3]  J. Hughes,et al.  Effect of blood transfusion on the carbon monoxide transfer factor of the lung in man. , 1978, Clinical science and molecular medicine.

[4]  J. Wolfe,et al.  Fatal lung scan in a case of pulmonary hypertension due to obliterative pulmonary vascular disease. , 1975, Chest.

[5]  J. O. Williams.  Death following injection of lung scanning agent in a case of pulmonary hypertension. , 1974, The British journal of radiology.

[6]  D. Desilets,et al.  Fatality immediately following rapid infusion of macroaggregates of 99mTc albumin (MAA) for lung scan. , 1968, Radiology.

[7]  J. Smith,et al.  Reaction after administration of macroaggregated albumin for a lung scan. , 1966, The New England journal of medicine.

[8]  W. Gold,et al.  Pulmonary-function response to radioisotope scanning of the lungs. , 1966, JAMA.

[9]  F. Roughton,et al.  Relative importance of diffusion and chemical reaction rates in determining rate of exchange of gases in the human lung, with special reference to true diffusing capacity of pulmonary membrane and volume of blood in the lung capillaries. , 1957, Journal of applied physiology.