The effects of continuous positive airway pressure on lung function in patients with acute exacerbation of heart failure

INTERVENTION: continuous positive airway pressure via nasal or full face mask at 10cm H2O pressure for 30 minutes from time of randomisation continuous positive airway therapy via nasal or full face mask at a starting pressure of 4cm H2O increasing by 2cm H2O every 5 minutes for a total of 30 minutes from time of randomisation CONDITION: Heart Failure PRIMARY OUTCOME: change in lung compliance as measured by the forced oscillation technique change in lung reactance as measured by the forced oscillation technique SECONDARY OUTCOME: change in BORG dyspnoea score change in clinical parameters (oxygen saturation and heart rate from pulse oximeter, respiratory rate via clinical examination, blood pressure via automatic sphygmanometer) INCLUSION CRITERIA: Patients diagnosed with an acute exacerbation of their heart failure Previous diagnosis of heart failure based on echocardiography Stable clincial status: respiratory rate <35 bpm, oxygen saturation via pulse oximeter(SpO2) > or equal to 85% on room air, systolic blood pressure > 90mmHg, clinically well perfused and able to speak in sentences Co‐operative and able to give consent