Acute effects of CPAP vs BiPAP low or high intensity in patients with severe congestive heart failure

Abstract

OBJECTIVE: To analyze the acute effects of noninvasive ventilation (NIV) on cardiac function and pulmonary ventilation in patients with congestive heart failure (CHF).

METHOD: Prospective, intervention, randomized study. Seven patients (4 men and 3 women) with stable chronic CHF with left ventricular ejection fraction (EF) ≤ 35%; mean age 54±28,9 years. Interventions: CPAP (10 cmH₂O), BiPAP (15/10 and 25/10 cmH₂O) of inspiratory and expiratory pressures respectively, via facial mask. NIV aplication lasted 20 min each, with periods of spontaneous breathing for 30 min between them as a washout period. Myocardial performance and changes were measured using clinical and echocardiography parameters. Statistically significant (p<0,05). RESULTS: CPAP significantly decrease of HR (pre: 80,6±11,2, post: 78,2±11,4bpm, p=0,004) and E/E'septal (pre: 18,5±11,6, post: 17,7±13,2bpm, p=0,03) and increased TV (pré: 5,05 ± 1,61; pós: 9,36 ± 5,50 L/min, p= 0,01). BiPAP significantly decrease of HR (pre: 80±11, post: 77±10bpm, p=0,01), TV (pré: 5,05 ± 1,61; pós: 9,36 ± 5,50 L/min, p= 0,01) and EtCO₂ (pre: 35±3; post: 25±7mmHg, p=0,05); no significantly decrease of E/E'septal (pre: 17,35±13,2, post: 17,4±12,2bpm, p=0,21) and increased SpO₂ (pre: 97±1,5, post: 98±1,4%, p=0,05). High intensity BiPAP (25/10) decreased EtCO₂ (pre: 35,4±3,6, post: 27±5,1mmHg, p=0,02) and increased PCP (pre: 22,4±10, post: 28,3±13,1, p=0,01), TV (pré: 5,16 ± 1,86; pós: 15,55 ± 4,84 L/min, p= 0,002) and SpO₂ (pre: 96,7±1,2, post: 98,7±1,4%, p=0,01). CONCLUSION: These preliminary results show reduces ventricular preload and that high intensity increases PCP in patients with severe stable CHF.