Ventilatory and hemodynamic effects of continuous positive airway pressure in left heart failure.

Abstract

The ventilatory and hemodynamic effects of continuous positive airway pressure (CPAP) delivered via a face mask (at 0, 5, and 10 cm H2O, and after a return to 0 cm H2O) were studied in nine patients with acute left heart failure (pulmonary artery occlusion pressure [PAOP] > or = 18 mm Hg, and cardiac index [CI] < or = 2.8 L/min/m2). CPAP at 10 cm H2O induced an improvement in lung compliance (60 +/- 10 ml/cm H2O to 87 +/- 20 ml/cm H2O, p < 0.05) and in lung and airway resistance (5.7 +/- 1.0 cm H2O/L/s to 3.4 +/- 1.0 cm H2O/L/s, p < 0.05), a reduction in work of breathing (18 +/- 3 J/min to 12 +/- 2 J/min, p < 0.05), and in the pressure-time index of the respiratory muscles (279 +/- 22 cm H2O/s/min to 174 +/- 25 cm H2O/s/min, p < 0.05), without significant changes in breathing pattern. Despite a significant reduction in the negative swings in intrathoracic pressure (15.2 +/- 1.9 cm H2O to 10.8 +/- 1.8 cm H2O, p < 0.001), no significant change was observed in CI or stroke volume during CPAP. However, mean transmural filling pressures decreased significantly with CPAP, suggesting a better cardiac performance. Neither the level of stroke volume nor of PAOP, was predictive of changes in CI or in stroke volume. In patients with respiratory insufficiency caused by congestive heart failure (CHF), CPAP reduces respiratory muscle effort without altering cardiac output. The slight decrease in mean transmural left and right atrial pressures suggests an improvement in cardiac performance.

Benefícios da ventilação não-invasiva após extubação no pós-operatório de cirurgia cardíaca

“…The individualized adjustments of the EPAP may have affected the results reported by this study, based on studies on the hemodynamic effects of continuous positive airway pressure (CPAP). Hence, a constant value of EPAP was maintained to prevent any event related to a reduction in the cardiac output [16][17][18][19].…”

Heart Failure and the Lung

“…Lung compliance improves and lung resistance falls with CPAP reducing the work of breathing (WOB). 79 There is also a reduction in the intrathoracic pressure swings and respiratory rate, representing a fall in respiratory muscle effort and leading to reduced left ventricular transmural pressure. 80 It has been previously demonstrated that as WOB increases, there is significant increase in blood flow to the respiratory muscles and an attendant increase in oxygen consumption.…”

Bi-level Versus Continuous Positive Airway Pressure in Acute Cardiogenic Pulmonary Edema: A Randomized Control Trial

“…Over the past three decades, application of noninvasive ventilation (NIV) either with continuous positive airway pressure (CPAP) or Bi-level positive airway pressure (Bi-PAP) has been used with the standardized medical treatment as an effective therapeutic approach to treat ACPE [5][6][7][8][9][10].…”

“…The goals of NIV use in the treatment of ACPE are to improve oxygenation, reduce the effort of breathing and increase cardiac output and decreased left ventricular preand after-load [5][6][7][8].…”