[Effects of nifedipine in patients with unstable chronic obstructive pulmonary disease]

The hemodynamic and gas exchange effects of 20 mg of nifedipine (NFD), at rest and exercise were evaluated in seven patients with unstable COPD and pulmonary hypertension. The cause of instability was pulmonary infection (n = 6) and pulmonary emboli (n = 1). At rest, pulmonary hypertension (Pp = 40 +/- 3 mmHg), severe hypoxemia (PaO2 +/- 2 mmHg) and elevated pulmonary vascular resistance (Rp) = 9 +/- .6 u.sq.m, were found. At exercise, Pp raised to 52 +/- 5 mmHg with no change in cardiac index (CI), Rp or gas exchange. After NFD at rest, significant (p less than 0.05) increases in CI, oxygen transport and venous admixture occurred. Also, Rp and systemic arterial pressure and resistance decreased significantly. Pp and blood gas exchange did not vary. Rp and systemic resistance were lower at exercise after NFD than without the drug with no change in blood gas exchange. The pulmonary flow pressure relationship showed a right shift after NFD in both, rest and exercise conditions. We conclude that NFD can be of value for the management of pulmonary hypertension that aggravates COPD.