Physiologic changes following bilateral carotid-body resection in patients with chronic obstructive pulmonary disease.

In an attempt to establish the characteristic pattern of change in (1) indices of pulmonary function, (2) arterial blood gas, and (3) arterial acid-base status which result from bilateral carotid body resection (BCBR), we analyzed the results of 146 consecutive patients with severe chronic obstructive pulmonary disease who had undergone BCBR at a single hospital site. In addition, we analyzed the results of incremental exercise testing in 21 similar patients, performed at a separate hospital. On average, TLC, FRC, and RV all decreased after surgery, whereas FEV1 increased. Although the data were highly variable, PaO2 decreased on average in proportion to the increase in PaCO2. The smaller group exercised to a higher metabolic rate after surgery; maximum ventilation, however, was unchanged. This led to a further fall in PaO2 and increase in PaCO2. We conclude that individual patient responses to BCBR are highly variable, but the procedure typically results in a small further hypoxemia and hypercapnia with no further impairment to pulmonary function.