Discover Portal

man in hospital receiving oxygen through a mask

NIHR Signal Providing pressurised air through a mask may improve outcomes for people with deteriorating heart failure

Published on 18 June 2019

doi: 10.3310/signal-000780

Non-invasive positive pressure ventilation may help people with rapidly deteriorating heart failure who become short of breath due to fluid build-up in the lungs. For people not requiring immediate mechanical ventilation using an endotracheal tube, this approach may reduce the risk of death in hospital and the need for intubation.

This review evaluated 24 trials of 2,664 adults comparing a group who received air under pressure through a mask, to a group receiving standard medical care. These types of masks are not routinely used for all people with deteriorating heart failure currently. However, this review found that they may be beneficial earlier in the progression of the condition, and this can avoid escalation of care to more invasive ventilation.

The evidence was not strong enough to say that the techniques shortened hospital stay or reduced heart attacks.

Share your views on the research.

Why was this study needed?

There are more than 580,000 people diagnosed with heart failure in the UK, and there are thought to be thousands more who are living with the condition. In 2017/18, there were 57,926 admissions for people with deteriorating heart failure that had caused pulmonary oedema.

Symptoms of pulmonary oedema include difficulty breathing, shortness of breath when lying down, cough and fatigue. Medications aim to reduce the fluid, increase the blood supply to the heart and treat the underlying cause.

This Cochrane review aimed to investigate whether adding non-invasive positive pressure ventilation to usual medical care in adults in this situation reduces rates of deaths, acute myocardial infarction (heart attacks), hospital length of stay or the need for intubation for mechanical ventilation. The researchers wanted to evaluate the impact of new literature available since the last version of this review, first published in May 2013.

What did this study do?

This systematic review and meta-analyses evaluated 24 parallel-design randomised controlled trials which compared non-invasive positive pressure ventilation to standard medical care in 2,664 adults with acute cardiogenic pulmonary oedema. Their average age was 73.

Ventilation could be received nasally or using a face mask supplying pressurised air using two techniques: via continuous positive airway pressure or via bi-level positive airway pressure, a two-level variation.

The studies were conducted in 14 countries, three of them in the UK. They varied in size from eight to 1,069 participants. Where clear, the follow-up period ranged from one to 41 days. Ten studies were in the emergency department and eight in intensive care.

The researchers reported lack of blinding and inconsistent reporting of outcomes which should be kept in mind when interpreting the results, though blinding is unlikely to have been possible in trials of this intervention in this setting.

What did it find?

  • Non-invasive positive pressure ventilation may reduce hospital mortality from 17.6% to 11.4% (risk ratio [RR] 0.65, 95% confidence interval [CI] 0.51 to 0.82; 2,484 adults, 21 studies, low quality evidence).
  • Fewer people needed an endotracheal tube for mechanical ventilation if they had used non-invasive positive pressure ventilation first – 15.4% needed intubation following standard care compared with 7.5% after the non-invasive technique (RR 0.49, 95% CI 0.28 to 0.62; 2,449 adults, 20 studies, moderate-quality evidence).
  • No difference was observed for the use of non-invasive positive pressure ventilation compared with standard medical care for the incidence of acute myocardial infarction, which occurred in 42.1% of people on standard care compared with 43.3% on non-invasive techniques or in length of stay.
  • The main adverse effect was discomfort from wearing the mask. Other events, such as swelling of the stomach, were rare.

What does current guidance say on this issue?

NICE 2014 guidelines do not recommend routine use of non-invasive positive pressure ventilation in individuals presenting with acute cardiogenic pulmonary oedema.

The guidelines suggest that in severe cases, for example, when a person with acute heart failure has particular difficulty breathing, respiratory failure or reduced consciousness, that ventilation should be considered without delay.

What are the implications?

The findings support consideration of broader indication for non-invasive positive pressure ventilation in deteriorating patients with heart failure as it is relatively safe and may improve mortality rates.

It remains unclear, from this research, at what point it should be started and which of the non-invasive positive pressure ventilation techniques might be best.

Given the large number of admissions for acute heart failure each year, and the need for resources and anaesthetist supervision, there could be resource implications if these techniques are to be used earlier on. Reduced need for more invasive mechanical ventilation, such as intubation, will be favoured by patients.

Citation and Funding

Berbenetz N, Wang Y, Brown J et al. Non-invasive positive pressure ventilation (CPAP or bilevel NPPV) for cardiogenic pulmonary oedema. Cochrane Database Syst Rev. 2019;4:CD005351.

Cochrane UK and the Heart Cochrane Review Group are supported by NIHR infrastructure funding.

Bibliography

British Heart Foundation. Statistics factsheet - UK. London: British Heart Foundation; 2019.

NHS Digital. Hospital admitted patient care activity, 2017-18: diagnosis. London: Department of Health and Social Care; 2018.

NICE. Acute heart failure: diagnosis and management. CG187. London: National Institute for Health and Care Excellence; 2014.

Why was this study needed?

There are more than 580,000 people diagnosed with heart failure in the UK, and there are thought to be thousands more who are living with the condition. In 2017/18, there were 57,926 admissions for people with deteriorating heart failure that had caused pulmonary oedema.

Symptoms of pulmonary oedema include difficulty breathing, shortness of breath when lying down, cough and fatigue. Medications aim to reduce the fluid, increase the blood supply to the heart and treat the underlying cause.

This Cochrane review aimed to investigate whether adding non-invasive positive pressure ventilation to usual medical care in adults in this situation reduces rates of deaths, acute myocardial infarction (heart attacks), hospital length of stay or the need for intubation for mechanical ventilation. The researchers wanted to evaluate the impact of new literature available since the last version of this review, first published in May 2013.

What did this study do?

This systematic review and meta-analyses evaluated 24 parallel-design randomised controlled trials which compared non-invasive positive pressure ventilation to standard medical care in 2,664 adults with acute cardiogenic pulmonary oedema. Their average age was 73.

Ventilation could be received nasally or using a face mask supplying pressurised air using two techniques: via continuous positive airway pressure or via bi-level positive airway pressure, a two-level variation.

The studies were conducted in 14 countries, three of them in the UK. They varied in size from eight to 1,069 participants. Where clear, the follow-up period ranged from one to 41 days. Ten studies were in the emergency department and eight in intensive care.

The researchers reported lack of blinding and inconsistent reporting of outcomes which should be kept in mind when interpreting the results, though blinding is unlikely to have been possible in trials of this intervention in this setting.

What did it find?

  • Non-invasive positive pressure ventilation may reduce hospital mortality from 17.6% to 11.4% (risk ratio [RR] 0.65, 95% confidence interval [CI] 0.51 to 0.82; 2,484 adults, 21 studies, low quality evidence).
  • Fewer people needed an endotracheal tube for mechanical ventilation if they had used non-invasive positive pressure ventilation first – 15.4% needed intubation following standard care compared with 7.5% after the non-invasive technique (RR 0.49, 95% CI 0.28 to 0.62; 2,449 adults, 20 studies, moderate-quality evidence).
  • No difference was observed for the use of non-invasive positive pressure ventilation compared with standard medical care for the incidence of acute myocardial infarction, which occurred in 42.1% of people on standard care compared with 43.3% on non-invasive techniques or in length of stay.
  • The main adverse effect was discomfort from wearing the mask. Other events, such as swelling of the stomach, were rare.

What does current guidance say on this issue?

NICE 2014 guidelines do not recommend routine use of non-invasive positive pressure ventilation in individuals presenting with acute cardiogenic pulmonary oedema.

The guidelines suggest that in severe cases, for example, when a person with acute heart failure has particular difficulty breathing, respiratory failure or reduced consciousness, that ventilation should be considered without delay.

What are the implications?

The findings support consideration of broader indication for non-invasive positive pressure ventilation in deteriorating patients with heart failure as it is relatively safe and may improve mortality rates.

It remains unclear, from this research, at what point it should be started and which of the non-invasive positive pressure ventilation techniques might be best.

Given the large number of admissions for acute heart failure each year, and the need for resources and anaesthetist supervision, there could be resource implications if these techniques are to be used earlier on. Reduced need for more invasive mechanical ventilation, such as intubation, will be favoured by patients.

Citation and Funding

Berbenetz N, Wang Y, Brown J et al. Non-invasive positive pressure ventilation (CPAP or bilevel NPPV) for cardiogenic pulmonary oedema. Cochrane Database Syst Rev. 2019;4:CD005351.

Cochrane UK and the Heart Cochrane Review Group are supported by NIHR infrastructure funding.

Bibliography

British Heart Foundation. Statistics factsheet - UK. London: British Heart Foundation; 2019.

NHS Digital. Hospital admitted patient care activity, 2017-18: diagnosis. London: Department of Health and Social Care; 2018.

NICE. Acute heart failure: diagnosis and management. CG187. London: National Institute for Health and Care Excellence; 2014.

Non-invasive positive pressure ventilation (CPAP or bilevel NPPV) for cardiogenic pulmonary oedema

Published on 6 April 2019

Berbenetz, N.,Wang, Y.,Brown, J.,Godfrey, C.,Ahmad, M.,Vital, F. M.,Lambiase, P.,Banerjee, A.,Bakhai, A.,Chong, M.

Cochrane Database Syst Rev Volume 4 , 2019

BACKGROUND: Non-invasive positive pressure ventilation (NPPV) has been used to treat respiratory distress due to acute cardiogenic pulmonary oedema (ACPE). We performed a systematic review and meta-analysis update on NPPV for adults presenting with ACPE. OBJECTIVES: To evaluate the safety and effectiveness of NPPV compared to standard medical care (SMC) for adults with ACPE. The primary outcome was hospital mortality. Important secondary outcomes were endotracheal intubation, treatment intolerance, hospital and intensive care unit length of stay, rates of acute myocardial infarction, and adverse event rates. SEARCH METHODS: We searched CENTRAL (CRS Web, 20 September 2018), MEDLINE (Ovid, 1946 to 19 September 2018), Embase (Ovid, 1974 to 19 September 2018), CINAHL Plus (EBSCO, 1937 to 19 September 2018), LILACS, WHO ICTRP, and clinicaltrials.gov. We also reviewed reference lists of included studies. We applied no language restrictions. SELECTION CRITERIA: We included blinded or unblinded randomised controlled trials in adults with ACPE. Participants had to be randomised to NPPV (continuous positive airway pressure (CPAP) or bilevel NPPV) plus standard medical care (SMC) compared with SMC alone. DATA COLLECTION AND ANALYSIS: Two review authors independently screened and selected articles for inclusion. We extracted data with a standardised data collection form. We evaluated the risks of bias of each study using the Cochrane 'Risk of bias' tool. We assessed evidence quality for each outcome using the GRADE recommendations. MAIN RESULTS: We included 24 studies (2664 participants) of adult participants (older than 18 years of age) with respiratory distress due to ACPE, not requiring immediate mechanical ventilation. People with ACPE presented either to an Emergency Department or were inpatients. ACPE treatment was provided in an intensive care or Emergency Department setting. There was a median follow-up of 13 days for hospital mortality, one day for endotracheal intubation, and three days for acute myocardial infarction. Compared with SMC, NPPV may reduce hospital mortality (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.51 to 0.82; participants = 2484; studies = 21; I(2) = 6%; low quality of evidence) with a number needed to treat for an additional beneficial outcome (NNTB) of 17 (NNTB 12 to 32). NPPV probably reduces endotracheal intubation rates (RR 0.49, 95% CI 0.38 to 0.62; participants = 2449; studies = 20; I(2) = 0%; moderate quality of evidence) with a NNTB of 13 (NNTB 11 to 18). There is probably little or no difference in acute myocardial infarction (AMI) incidence with NPPV compared to SMC for ACPE (RR 1.03, 95% CI 0.91 to 1.16; participants = 1313; studies = 5; I(2) = 0%; moderate quality of evidence). We are uncertain as to whether NPPV increases hospital length of stay (mean difference (MD) -0.31 days, 95% CI -1.23 to 0.61; participants = 1714; studies = 11; I(2) = 55%; very low quality of evidence). Adverse events were generally similar between NPPV and SMC groups, but evidence was of low quality. AUTHORS' CONCLUSIONS: Our review provides support for continued clinical application of NPPV for ACPE, to improve outcomes such as hospital mortality and intubation rates. NPPV is a safe intervention with similar adverse event rates to SMC alone. Additional research is needed to determine if specific subgroups of people with ACPE have greater benefit of NPPV compared to SMC. Future research should explore the benefit of NPPV for ACPE patients with hypercapnia.

Expert commentary

In acute cardiogenic pulmonary oedema, there is a need to understand the benefit of positive airway pressure therapy and how it affects patients’ symptoms and outcomes, from well-evidenced randomised controlled trials. Existing trials use different modes of positive airway pressure treatment and different intensities.

This Cochrane review’s results indicate that safe delivery of non-invasive positive airway pressure therapy in standard clinical settings can be a potent tool to improve outcomes for patients with acute cardiogenic pulmonary oedema.

Delivery of such treatment in acute medical setting needs to be provided for across the NHS, as it comes with significant expertise, requires technical support and a functioning infrastructure and educational support of the involved services.

Professor Joerg Steier, Professor of Respiratory and Sleep Medicine, Guy’s & St Thomas’ NHS Foundation Trust, King’s College London

The commentator declares no conflicting interests