Noninvasive ventilation in acute cardiogenic pulmonary edema with haemodynamic instability

Background: Although noninvasive ventilation (NIV) in acute cardiogenic pulmonary edema (ACPE) is widely used, its use in patients with unstable hemodynamics is contradictory. Aims: To evaluate NIV use in ACPE with low systolic blood pressure (SBP) and search for the correlates of it9s success. Methods: Prospective interventional trial of all 22 patients with ACPE with SBP 75-90 mm Hg, with no acute arrhythmia, SaO2 90% on spontaneous breathing with 10 l per minute oxygen, cooperative, not hypercapneic, with low cardiac output due to acute myocardial infarction, mitral regurgitation or congestive heart failure, was done from July 1, 2010 through December 31, 2011. All patients were immediately started on conventional therapy (dobutamine and/or dopamine, morphine, furosemide, nitroglycerine) and NIV through a face mask with FiO2=1.0, initial PEEP 5 cm H2O and pressure support (PS) 5 cm H2O. Hemodynamic parameters, SaO2, central venous saturation (ScvO2), respiratory rate (RR) and tidal volume (Vt) were documented every 3 minutes. If no relief in 3 minutes, PEEP was enhanced to 7 cm H2O and after next 3 minutes PS added to 7 cm H2O. Results: All patients had SaO2 90% and SBP≥90 mm Hg after 10 minutes. If at this moment RR was 30 and Vt 5 ml/kg of body weight, or more than low doses of cardiotonics were needed, the patient was intubated (4 patients).After 30 minutes, those who needed FiO2 60% on NIV, were oluguric and failed to rise ScvO2 above initial, were intubated (2 patients). No intubation was needed in 16 patients (73%). No factors correlated with NIV failure. Conclusion: In selected hemodynamically unstable patients with ACPE NIV helps avoid intubation.