RESUMEN
Mild to severe respiratory dysfunction is still a common issue after cardiac surgery. Postoperative respiratory complications are associated with prolonged hospitalization and worse survival. In this high-risk surgery, non-invasive ventilation could have relevant positive effects. The present narrative concise review aims to summarize available data on the role of non-invasive ventilation before and after cardiac surgery. Non-invasive ventilation exerts its main effects on the pulmonary and on the cardiovascular systems. Non-invasive ventilation can be applied to prevent acute respiratory failure; it can also be prescribed as a curative tool to treat an established postoperative acute respiratory failure. Non-invasive ventilation could also be applied to wean patients from mechanical ventilation. When applied as a preventive tool, the main scope is the prevention of pneumonia by resolving or preventing atelectasis. So far, limited (but encouraging) data are available: its routine use in all patients to prevent postoperative acute respiratory failure cannot be recommended. Non-invasive ventilation to treat postoperative acute respiratory failure has been evaluated more extensively. A failure rate from 10 to 55% was reported. Safety appears preserved, with no relevant hemodynamic complication reported. Non-invasive ventilation has also been applied during percutaneous aortic valve implant in patients unable to lie supine due to severe respiratory limitation and orthopnea. In conclusion, non-invasive ventilation has the potential to be very useful before and after cardiac surgery. So far, results are promising but available data are limited. Training and experience are essential to obtain positive results and to avoid complications.
RESUMEN
BACKGROUND: Non-invasive ventilation (NIV) can prevent or treat postoperative acute respiratory failure. NIV after discharge from the Intensive Care Unit (ICU) has never been described in the setting of cardiac surgery. METHODS: This study enrolled 85 patients who received NIV in the main ward as treatment for respiratory failure. The patients had the following conditions: atelectasis (45 patients), pleural effusion (20 patients), pulmonary congestion (13 patients), diaphragm hemiparesis (6 patients), pneumonia (4 patients) or a combination of these conditions. RESULTS: Eighty-three patients were discharged from the hospital in good condition and without need for further NIV treatment, while two died in-hospital. Four of the 85 patients had an immediate NIV failure, while eight patients had delayed NIV failure. Only one patient had a NIV-related complication represented by hypotension after NIV institution. In this patient, NIV was interrupted with no consequences. Major mistakes were mask malpositioning with excessive air leaks (7 patients), incorrect preparation of the circuit (one patient), and oxygen tube disconnection (one patient). Minor mistakes (sub-optimal positioning of the face mask without excessive air leaks) were noted by the respiratory therapists for all patients and were managed by slightly modifying the mask position. CONCLUSION: In our experience, postoperative NIV is feasible, safe and effective in treating postoperative acute respiratory failure when applied in the cardiac surgical ward, preserving intensive care unit beds for surgical activity. A respiratory therapy service managed the treatment in conjunction with ward nurses, while an anesthesiologist and a cardiologist served as consultants.