Effect of Almitrine on Ventilation-Perfusion Distribution in Adult Respiratory Distress Syndrome

Publisher Website
Google Scholar
Abstract
Almitrine improves ventilation/perfusion relationships (a/) in COPD, but its effects in ARDS, in which a/ mismatching is the cause of severe hypoxemia, are not known. The effects of almitrine on pulmonary gas exchange and circulation were assessed in 9 patients with ARDS who were sedated, paralyzed, and mechanically ventilated at constant FiO2 (range, 0.48 to 0.74). Systemic and pulmonary hemodynamics, conventional gas exchange, and the a/ distribution by the multiple inert gas elimination technique (MIGT) were measured before (baseline), during (ALM 15), at the end of (ALM 30), and at 30-min intervals after (POSTALM 30, 60, and 90) the intravenous infusion of 0.5 mg/kg body weight of almitrine over 30 min. Almitrine significantly increased PaO2 from 78 ± 15 mm Hg to 140 ± 49 at ALM 15 and 138 ± 52 at ALM 30. AaPO2 and s/t decreased during the administration of the drug. The MIGT showed that almitrine redistributed pulmonary blood flow from shunt areas (reduction from 29 ± 11 to 17 ± 11% of t) to lung units with normal a/ ratios (increase from 63 ± 9 to 73 ± 6% of t). The pa increased from 26 ± 5 to 30 ± 5 mm Hg without changes in t. Changes were transient, returning toward baseline 30 min after stopping the infusion of the drug. Almitrine significantly reduced the a/ inequalities present in ARDS and may be useful in the management of those patients.