Effect of almitrine on ventilation-perfusion distribution in adult respiratory distress syndrome.
Almitrine improves ventilation/perfusion relationships (VA/Q) in COPD, but its effects in ARDS, in which VA/Q 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 FlO2 (range, 0.48 to 0.74). Systemic and pulmonary hemodynamics, conventional gas exchange, and the VA/Q 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 QS/QT 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 QT) to lung units with normal VA/Q ratios (increase from 63 +/- 9 to 73 +/- 6% of QT). The Ppa increased from 26 +/- 5 to 30 +/- 5 mm Hg without changes in QT. Changes were transient, returning toward baseline 30 min after stopping the infusion of the drug. Almitrine significantly reduced the VA/Q inequalities present in ARDS and may be useful in the management of those patients.
Reyes
A
A
Servicio de Neumología, Hospital Clínico, Universidad de Barcelona, Spain.
Roca
J
J
Rodriguez-Roisin
R
R
Torres
A
A
Ussetti
P
P
Wagner
P D
PD
D000328:Adult; D000368:Aged; D015765:Almitrine; D002302:Cardiac Output / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010879:Piperazines / Q000494:pharmacology*; D011652:Pulmonary Circulation / Q000187:drug effects; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D012128:Respiratory Distress Syndrome / Q000097:blood / Q000503:physiopathology*; D014655:Vascular Resistance / Q000187:drug effects; D014692:Ventilation-Perfusion Ratio / Q000187:drug effects*
D010879:Piperazines; D015765:Almitrine; D010100:Oxygen