Hemodynamic impact of alveolar recruitment maneuver in patients evolving with cardiogenic shock in the immediate postoperative period of myocardial revascularization.

BACKGROUND AND OBJECTIVES

Alveolar recruitment maneuver (ARM) with pressures of 40 cmH2O in the airways is effective in the reversal of atelectasis after myocardial revascularization (MR); however, there is a lack of studies evaluating the hemodynamic impact of this maneuver in patients who evolve with cardiogenic shock after MR. The objective of this study was to test the hemodynamic tolerance to ARM in patients who develop cardiogenic shock after MR.

METHODS

Ten hypoxemic patients in cardiogenic shock after MR were evaluated after admission to the ICU and hemodynamic stabilization. Ventilatory adjustments included tidal volume of 8 mL x kg(-1), PEEP 5 cmH2O, RR 12, and FiO2 0.6. Continuous pressure of 40 cmH2O was applied to the airways for 40 seconds in three cycles. Between cycles, patients were ventilated for 30 seconds, and after the last cycle, PEEP was set at 10 cmH2O. Hemodynamic measurements were obtained 1, 10, 30, and 60 minutes after ARM, and arterial and venous blood samples were drawn 10 and 60 minutes after the maneuver to determine lactate levels and blood gases. ANOVA and the Friedman test were used to analyze the data. A p of 0.05 was considered significant.

RESULTS

Alveolar recruitment maneuver increased the ratio PaO2/ FiO2 from 87 to 129.5 after 10 minutes and to 120 after 60 minutes (p < 0.05) and reduced pulmonary shunting from 30% to 20% (p < 0.05). Hemodynamic changes or changes in oxygen transport immediately after or up to 60 minutes after the maneuver were not detected.

CONCLUSIONS

In patients who evolved to cardiogenic shock and hypoxemia after MR, ARM improved oxygenation and was well tolerated hemodynamically.