Chronic Obstructive Pulmonary Disease and Polycythemia

To the Editor.—  The editorial by William R. Barclay, MD (240:1520, 1978), regarding the report of Graham and Houston (240:1491, 1978) on the ability of persons with mild to moderate chronic obstructive pulmonary disease to tolerate short periods at high altitudes is worthy of note. Other factors also may warrant consideration, including the RBC mass. We recently observed a patient with previously undiagnosed chronic obstructive pulmonary disease who had polycythemia, gastrointestinal bleeding, and prolonged partial thromboplastin time (PTT), and who subsequently died of thrombotic complications. The case also illustrates the importance of ensuring that the required dilutional factors are met when determining the PTT. 10 20 30 40 50 60 70 Activated Partial Thromboplastin Time, s Variability of partial thromboplastin time with changes in ratio of sodium citrate to plasma volumes. Shaded area represents normal range (25 to 35 s) and demonstrates range of permissible sodium citrate dilution.

Report of