Noninvasive mechanical ventilation in patients with acute respiratory failure after cardiac surgery

To evaluate the feasibility and outcomes of protocol-driven noninvasive mechanical ventilation in patients with acute respiratory failure (ARF) after cardiac surgery.

From 2001 to 2004, a total of 2428 cardiac surgery patients admitted to our intensive care unit were observed. After exclusion of patients who received tracheostomy or were discharged while still on mechanical ventilation, 2261 patients with spontaneous breathing were further evaluated for ARF. Patients diagnosed with ARF were treated with intermittent noninvasive mechanical ventilation (NIV) if possible. Risk factors for the development of postoperative ARF as well as outcomes in patients with and without ARF were analyzed.

In 2261 spontaneously breathing postoperative cardiac surgical patients after primarily successful extubation, 799 patients (35%) were diagnosed with ARF. Fifty-six patients (7%) did not tolerate NIV treatment. In 743 patients (33%) intermittent NIV was performed. In patients with ARF, ejection fraction was lower, combined cardiac surgical procedures were more frequent, postoperative mechanical ventilation time was longer, and the severity of illness score (SAPS II) was higher (P < .05). The duration of catecholamine support was longer, and the transfusion rate was higher in the NIV group (P < .05); however, mortality did not differ between patients with ARF treated by NIV and patients without ARF.

Our study demonstrates the feasibility of NIV in patients after cardiac surgery. These results might suggest that NIV should be considered as first-line ventilatory support in ARF after cardiac surgery. A large randomized trial is warranted to confirm these findings.