The effects of intravenous almitrine on oxygenation and hemodynamics during one-lung ventilation

One-lung ventilation (OLV) induces an increase in pulmonary shunt sometimes associated with a decrease in Pao(2) despite ventilation with 100% oxygen. Pao(2) improvement has been reported in one-lung ventilated animals receiving IV almitrine, a pulmonary vasoconstrictor. We evaluated the ability of almitrine to prevent a decrease in Pao(2) during OLV. Patients without pulmonary hypertension undergoing OLV for lung surgery were randomly assigned to receive either placebo (Group P, n = 8) or almitrine infusion at a rate of 8 mug . kg(-1) . min(-1) (Group A, n = 8) from the start of OLV. Gasometric and hemodynamic values were recorded with the patient in the lateral decubitus position during two-lung ventilation and at 10-min intervals during CLV over a 30-min period (OLV-10, OLV-20, OLV-30). Compared with the values found during two-lung ventilation (434 +/- 22 mm Hg in Group P and 426 +/- 23 mm Hg in Group A), Pao(2) decreased at OLV-10 (305 +/- 46 = Hg), OLV-20 (203 +/- 20 mm Hg), and OLV-30 (178 +/- 18 mm Hg) in Group P (P < 0.05) and at OLV-20 (354 +/- 25 = Hg) and OLV-30 (325 +/- 17 mm Hg) in Group A (P < 0.05). Pao(2) values differed between the groups at OLV-20 and OLV-30 (P < 0.05). Pulmonary artery pressure and cardiac output did not change. In conclusion, 8 mug . kg(-1) . min(-1) IV almitrine prevents and limits the OLV-induced decrease in Pao(2) without causing any hemodynamic modification.