Indications and practical approach to non-invasive ventilation in acute heart failure

Abstract

In acute heart failure (AHF) syndromes significant respiratory failure (RF) is essentially seen in patients with acute cardiogenic pulmonary oedema (ACPE) or cardiogenic shock (CS). Non-invasive ventilation (NIV), the application of positive intrathoracic pressure through an interface, has shown to be useful in the treatment of moderate to severe RF in several scenarios. There are two main modalities of NIV: continuous positive airway pressure (CPAP) and pressure support ventilation (NIPSV) with positive end expiratory pressure. Appropriate equipment and experience is needed for NIPSV, whereas CPAP may be administered without a ventilator, not requiring special training. Both modalities have shown to be effective in ACPE, by a reduction of respiratory distress and the endotracheal intubation rate compared to conventional oxygen therapy, but the impact on mortality is less conclusive. Non-invasive ventilation is also indicated in patients with AHF associated to pulmonary disease and may be considered, after haemodynamic stabilization, in some patients with CS. There are no differences in the outcomes in the studies comparing both techniques, but CPAP is a simpler technique that may be preferred in low-equipped areas like the pre-hospital setting, while NIPSV may be preferable in patients with significant hypercapnia. The new modality 'high-flow nasal cannula' seems promising in cases of AHF with less severe RF. The correct selection of patients and interfaces, early application of the technique, the achievement of a good synchrony between patients and the ventilator avoiding excessive leakage, close monitoring, proactive management, and in some cases mild sedation, may warrant the success of the technique.

Noninvasive ventilation in acute respiratory failure: which recipe for success?

“…Acute hypoxaemic respiratory failure Cardiogenic pulmonary oedema Cardiogenic pulmonary oedema represents one of the main causes of ARF [37]. The application of NPPV in patients with ARF due to cardiogenic pulmonary oedema has been studied in several trials for a period of >30 years, starting with the use of CPAP at the end of the 1980s [6,38].…”

“…The rationale for applying a positive respiratory pressure concerns improvements in both the cardiovascular and respiratory systems. The former achieves a decrease in venous return with subsequent preload reduction in both right ventricle (RV) and left ventricle (LV), the latter takes advantages from intra-alveolar pressure against oedema with a reduction of the work of breathing and ensures the recruitment of collapsed alveoli, thus improving oxygenation [38].…”

“…However, other issues have to be taken into account as well as the increase in the pulmonary vascular resistance leading to an increased RV afterload and reduced LV compliance and stroke volume [38].…”

“…Benefits have been shown from both BiPAP and CPAP without clear evidence to recommend one modality over the other [1,6]. In contrast to CPAP, BiPAP provides additional support on inspiration, but can be less tolerated by the patient and may produce overassistance with higher inspiratory efforts [38].…”

Early identification of acute heart failure at the time of presentation: do natriuretic peptides make the difference?

“…This means also to identify specific therapeutic options like non‐invasive ventilation (NIV), which allow immediate reversal of hypoxia and therefore gain time for a more thorough diagnostic workup. NIV is, from the clinical viewpoint, a major breakthrough in acute dyspnea and hypoxia in the ED but has limited evidence from prospective clinical studies 19. Future interventional studies in AHF should therefore take into account the uncertainty of the exact diagnosis in the very acute phase and propose a more detailed workup to identify a more individualized patient population.…”