Randomised controlled trial of continuous positive airway pressure and standard oxygen therapy in acute pulmonary oedema; effects on plasma brain natriuretic peptide concentrations

Noninvasive Ventilation in the Cardiac Intensive Care Unit

Over the last several decades, the cardiac intensive care unit (CICU) has seen an increase in the complexity of the patient population and etiologies requiring CICU admission. Currently, respiratory failure is the most common reason for admission to the contemporary CICU. As a result, noninvasive ventilation (NIV), including noninvasive positive-pressure ventilation and high-flow nasal cannula, has been increasingly utilized in the management of patients admitted to the CICU. In this review, we detail the different NIV modalities and summarize the evidence supporting their use in conditions frequently encountered in the CICU. We describe the unique pathophysiologic interactions between positive pressure ventilation and left and/or right ventricular dysfunction. Additionally, we discuss the evidence and strategies for utilization of NIV as a method to reduce extubation failure in patients who required invasive mechanical ventilation. Lastly, we examine unique considerations for managing respiratory failure in certain, high-risk patient populations such as those with right ventricular failure, severe valvular disease, and adult congenital heart disease. Overall, it is critical for clinicians who practice in the CICU to be experts with the application, risks, benefits, and modalities of NIV in cardiac patients with respiratory failure.

Comparison of High Flow Nasal Cannula and Continuous Positive Airway Pressure in COVID-19 Patients With Acute Respiratory Distress Syndrome in Critical Care Unit: A Randomized Control Study

Background and objective Acute hypoxic respiratory failure in coronavirus disease 2019 (COVID-19) pneumonia has been treated with oxygen delivered by oxygen masks and non-invasive ventilation (NIV) with continuous positive airway pressure (CPAP), and more recently with high-flow nasal cannula (HFNC) devices. There is a paucity of randomized controlled trials to compare the efficacy of CPAP with HFNC in COVID-19 pneumonia. We conceptualized a randomized control study to compare the efficacy of HFNC and CPAP in reducing the need for invasive mechanical ventilation, estimation of mechanical ventilation-free days, and risk of intubation in COVID-19 patients with hypoxic respiratory failure. Methodology One hundred consecutive patients who satisfied the inclusion criteria were included in the trial. The patients were then randomly allocated to receive either CPAP or HFNC with settings as per the study protocol. The patients were deemed to have achieved the study endpoint when they were intubated due to any reason or successfully weaned from NIV to conventional oxygen therapies. The number of patients who required invasive ventilation and the number of invasive ventilation-free days were recorded and analyzed. Results Nineteen (38%) patients in the CPAP group and 30 (60%) patients in the HFNC group required invasive mechanical ventilation and the difference was statistically significant (p = 0.03, 95%CI: 0.1829-0.9129). The median number of days free of invasive mechanical ventilation in the CPAP group (median=5 (interquartile range (IQR(=5,6)) was more than in the HFNC group (median=4 (IQR=3,4)) and this difference was statistically significant (p<0.000). The secondary analysis of risk evaluation for intubation done using the Cox regression model showed no significant factors that could have contributed to intubation in the study population. The Kaplan-Meyer curve was used to express the probability of a patient getting intubated and the calculated hazard ratio was 2.29. Conclusion The administration of CPAP significantly reduced the intubation rate and prolonged invasive mechanical ventilation-free period in COVID-19 patients with hypoxic respiratory failure. We also inferred a two-fold increase in the risk of intubation in patients receiving HFNC compared to CPAP.

The association between cardiac involvement and long-term clinical outcomes in patients with Duchenne muscular dystrophy

Aims

Despite advances in contemporary cardiopulmonary therapies, cardiomyopathy remains the leading cause of death in patients with Duchenne muscular dystrophy (DMD). Also, the long‐term clinical outcomes of patients with DMD and cardiomyopathy is unknown. This study investigated long‐term clinical outcomes and their associated factors in patients with late‐stage DMD.

Methods and results

A total of 116 patients with late‐stage DMD (age > 15 years) were enrolled in this retrospective study. All enrolled patients were followed up at a single tertiary referral hospital. LV systolic dysfunction was dichotomously defined as reduced [left ventricular ejection fraction (LVEF) ≤ 40%] vs. preserved [>40%] based on the initial echocardiographic result. The primary endpoint was all‐cause death. The secondary endpoint was a composite event defined as death or unexpected hospitalization due to cardiovascular reasons including chest pain, dyspnoea, and generalized oedema. The patients were divided into preserved (n = 84, 72.4%) and reduced LVEF groups (n = 32, 27.6%). The mean age was 20.8 ± 5.9 years, the mean disease duration, 8.8 ± 3.7 years, and the mean follow‐up duration, 1708 ± 659 days. For primary endpoint, the reduced LVEF group showed a lower rate of overall survival (Reduced LVEF vs. Preserved LVEF; 81.3% vs. 98.8%, log‐rank P = 0.005). In the multivariable Cox regression analysis, brain‐natriuretic peptide (BNP) level (adjusted hazard ratio [HR] 1.088, 95% confidence interval [CI] 1.019–1.162, P = 0.011) and diuretic use (adjusted HR 9.279, 95%CI 1.651–52.148, P = 0.011) were significant predictors of all‐cause death in patients with DMD. For the secondary endpoint, the reduced LVEF group had a lower rate of freedom from composite events than the preserved LVEF group (65.6% vs. 86.9%, log‐rank P = 0.005). In the multivariable Cox regression analysis, BNP level (adjusted HR 1.057, 95%CI 1.005–1.112, P = 0.032) and diuretic use (adjusted HR 4.189, 95% CI 1.704–10.296, P = 0.002) were significant predictors of the composite event in patients with DMD.

Conclusions

Patients with DMD and reduced LVEF had worse clinical outcomes than those with preserved LVEF. BNP level and diuretic use were associated with adverse clinical outcomes in patients with late‐stage DMD, irrespective of LVEF.

National Trends in Incidence and Outcomes of Patients With Heart Failure Requiring Respiratory Support

Despite increasing medical complexity in patients with heart failure (HF), there are limited data on incidence and outcomes for patients with HF needing respiratory support. This study sought to examine contemporary trends of respiratory support strategies among patients with HF. Using the National Inpatient Sample, we identified adults aged greater than 18 years hospitalized with a primary diagnosis of HF. We assessed for trends in the use of invasive mechanical ventilation (IMV) and noninvasive ventilation (NIV), length of stay, hospital costs, and in-hospital mortality. From 2002 to 2014, we identified 9,508,768 HF hospitalizations, which included 202,340 (2.13%) and 257,549 (2.71%) patients that required IMV and NIV, respectively. Over the study period, the proportion of HF patients requiring IMV significantly decreased (3.25% in 2002 to 1.56% in 2014) whereas the use of NIV significantly increased from 0.95% to 7.25% (p_trend <0.001 for both). In-hospital mortality significantly increased for IMV (31.5% in 2002 to 38.6% in 2014) recipients and decreased for patients requiring NIV (9.0% to 5.6%, p_trend <0.0001 for both). The average length of stay was nearly 7 days longer in the IMV group (12.2 days) and 2 days longer in the NIV group (6.8 days; p <0.001 for both). Hospital charges have nearly tripled for patients requiring IMV ($99,358 in 2014, p_trend <0.001) and doubled for those requiring NIV ($37,539 in 2014, p_trend <0.001). In conclusion, respiratory support strategies for patients with HF have significantly evolved with increasing use of NIV as compared with IMV. However, the in-hospital mortality associated with respiratory failure remains unacceptably high.

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

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; I² = 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; I² = 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; I² = 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; I² = 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.

Non-Invasive Mechanical Ventilation Versus Continuous Positive Airway Pressure Relating to Cardiogenic Pulmonary Edema in an Intensive Care Unit

BACKGROUND

To compare the application of non-invasive ventilation (NIV) versus continuous positive airway pressure (CPAP) in the treatment of patients with cardiogenic pulmonary edema (CPE) admitted to an intensive care unit (ICU).

METHODS

In a prospective, randomized, controlled study performed in an ICU, patients with CPE were assigned to NIV (n=56) or CPAP (n=54). Primary outcome was intubation rate. Secondary outcomes included duration of ventilation, length of ICU and hospital stay, improvement of gas exchange, complications, ICU and hospital mortality, and 28-day mortality. The outcomes were analyzed in hypercapnic patients (PaCO₂>45mmHg) with no underlying chronic lung disease.

RESULTS

Both devices led to similar clinical and gas exchange improvement; however, in the first 60min of treatment a higher PaO₂/FiO₂ ratio was observed in the NIV group (205±112 in NIV vs. 150±84 in CPAP, P=.02). The rate of intubation was similar in both groups (9% in NIV vs. 9% in CPAP, P=1.0). There were no differences in duration of ventilation, ICU and length of hospital stay. There were no significant differences in ICU, hospital and 28-d mortality between groups. In the hypercapnic group, there were no differences between NIV and CPAP.

CONCLUSIONS

Either NIV or CPAP are recommended in patients with CPE in the ICU. Outcomes in the hypercapnic group with no chronic lung disease were similar using NIV or CPAP.

Pulmonary Oedema — A Life Threatening Disease

AIM

The aim was to describe the health history of patients after pulmonary oedema and investigate how they perceive their condition and treatment.

METHODS

In part one of the study medical records of patients treated for acute pulmonary oedema (n=44) were reviewed regarding social status, health history, medication and cause of the pulmonary oedema. In part two, interviews were performed focusing on the patients' conceptions of the illness, current situation and effects of pulmonary oedema on daily life.

RESULTS

One-year mortality was 65% and all but 3 patients had a previous heart diagnosis. Analyses of the interviews yielded five categories: A suffocating feeling; trust in care providers; medication - an annoyance but also a saviour; dealing with existential issues alone or with relatives; concurrent diseases affecting daily life.

CONCLUSION

Patients' who experience a pulmonary oedema have several heart-related conditions and a very poor prognosis. Experiencing pulmonary oedema is an anxiety-provoking situation and patients should be regularly and carefully monitored.

Pre-hospital non-invasive ventilation for acute respiratory failure: a systematic review and cost-effectiveness evaluation

BACKGROUND

Non-invasive ventilation (NIV), in the form of continuous positive airway pressure (CPAP) or bilevel inspiratory positive airway pressure (BiPAP), is used in hospital to treat patients with acute respiratory failure. Pre-hospital NIV may be more effective than in-hospital NIV but requires additional ambulance service resources.

OBJECTIVES

We aimed to determine the clinical effectiveness and cost-effectiveness of pre-hospital NIV compared with usual care for adults presenting to the emergency services with acute respiratory failure and to identify priorities for future research.

DATA SOURCES

Fourteen electronic databases and research registers (including MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE, and Cumulative Index to Nursing and Allied Health Literature) were searched from inception to August 2013, supplemented by hand-searching reference lists and contacting experts in the field.

REVIEW METHODS

We included all randomised or quasi-randomised controlled trials of pre-hospital NIV in patients with acute respiratory failure. Methodological quality was assessed according to established criteria. An aggregate data network meta-analysis (NMA) of mortality and intubation was used to jointly estimate intervention effects relative to usual care. A NMA, using individual patient-level data (IPD) and aggregate data where IPD were not available, was carried out to assess whether or not covariates were treatment effect modifiers. A de novo economic model was developed to explore the costs and health outcomes when pre-hospital NIV (specifically CPAP provided by paramedics) and standard care (in-hospital NIV) were applied to a hypothetical cohort of patients with acute respiratory failure.

RESULTS

The literature searches identified 2284 citations. Of the 10 studies that met the inclusion criteria, eight were randomised controlled trials and two were quasi-randomised trials (six CPAP; four BiPAP; sample sizes 23-207 participants). IPD were available from seven trials (650 patients). The aggregate data NMA suggested that CPAP was the most effective treatment in terms of mortality (probability = 0.989) and intubation rate (probability = 0.639), and reduced both mortality [odds ratio (OR) 0.41, 95% credible interval (CrI) 0.20 to 0.77] and intubation rate (OR 0.32, 95% CrI 0.17 to 0.62) compared with standard care. The effect of BiPAP on mortality (OR 1.94, 95% CrI 0.65 to 6.14) and intubation rate (OR 0.40, 95% CrI 0.14 to 1.16) compared with standard care was uncertain. The combined IPD and aggregate data NMA suggested that sex was a statistically significant treatment effect modifier for mortality. The economic analysis showed that pre-hospital CPAP was more effective and more expensive than standard care, with an incremental cost-effectiveness ratio of £20,514 per quality-adjusted life-year (QALY) and a 49.5% probability of being cost-effective at the £20,000-per-QALY threshold. Variation in the incidence of eligible patients had a marked impact on cost-effectiveness and the expected value of sample information for a future randomised trial.

LIMITATIONS

The meta-analysis lacked power to detect potentially important differences in outcome (particularly for BiPAP), the intervention was not always compared with the best alternative care (in-hospital NIV) in the primary studies and findings may not be generalisable.

CONCLUSIONS

Pre-hospital CPAP can reduce mortality and intubation rates, but cost-effectiveness is uncertain and the value of further randomised evaluation depends on the incidence of suitable patients. A feasibility study is required to determine if a large pragmatic trial of clinical effectiveness and cost-effectiveness is appropriate.

STUDY REGISTRATION

The study is registered as PROSPERO CRD42012002933.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Sympathetic crashing acute pulmonary edema

Sympathetic crashing acute pulmonary edema (SCAPE) is the extreme end of the spectrum of acute pulmonary edema. It is important to understand this disease as it is relatively common in the emergency department (ED) and has better outcomes when managed appropriately. The patients have an abrupt redistribution of fluid in the lungs, and when treated promptly and effectively, these patients will rapidly recover. Noninvasive ventilation and intravenous nitrates are the mainstay of treatment which should be started within minutes of the patient's arrival to the ED. Use of morphine and intravenous loop diuretics, although popular, has poor scientific evidence.

Update: Acute Heart Failure (VII): Nonpharmacological Management of Acute Heart Failure

Acute heart failure is a major and growing public health problem worldwide with high morbidity, mortality, and cost. Despite recent advances in pharmacological management, the prognosis of patients with acute decompensated heart failure remains poor. Consequently, nonpharmacological approaches are being developed and increasingly used. Such techniques may include several modalities of ventilation, ultrafiltration, mechanical circulatory support, myocardial revascularization, and surgical treatment, among others. This document reviews the nonpharmacological approach in acute heart failure, indications, and prognostic implications.

The effect of adaptive servo-ventilation on dyspnoea, haemodynamic parameters and plasma catecholamine concentrations in acute cardiogenic pulmonary oedema

BACKGROUND

Adaptive servo-ventilation has a potential sympathoinhibitory effect in acute cardiogenic pulmonary oedema (ACPO).

AIMS

To evaluate the acute effects of adaptive servo-ventilation in patients with ACPO.

METHODS

Fifty-eight consecutive patients with ACPO were divided into those who underwent adaptive servo-ventilation and those who received oxygen therapy alone as part of their immediate care. Visual analogue scale, vital signs, blood gas data and plasma catecholamine concentrations at baseline and 1 h during emergency care, and subsequent clinical events (death within 30 days, intubation within seven days or between seven and 30 days, and length of hospital stay) were assessed. Pre-matched and post-propensity score (PS)-matched datasets were analysed.

RESULTS

During the first hour of adaptive servo-ventilation, plasma catecholamine concentrations fell significantly (baseline versus 1 h: epinephrine p = 0.003, norepinephrine p < 0.001, dopamine p < 0.001), with falls in blood pressure, heart rate, respiratory rate and pCO2, and rise in HCO3 and pH. In the PS-matched model, visual analogue scale (p = 0.036), systolic blood pressure (from 153.8 ± 30.7 to 133.1 ± 16.3 mmHg; p = 0.025) and plasma dopamine concentration (p = 0.034) fell significantly in the adaptive servo-ventilation group compared with the oxygen therapy alone group. The clinical outcomes between the groups were comparable.

CONCLUSION

In patients with ACPO, emergency care using adaptive servo-ventilation attenuated plasma catecholamine concentrations and led to the improvement of dyspnoea, vital signs and acid-base balance, without adversely influencing clinical outcomes. Using adaptive servo-ventilation, rather than standard oxygen alone, may relieve dyspnoea and improve haemodynamic status, possibly by modulating sympathetic nerve activity.

Noninvasive ventilation in acute respiratory failure

After the institution of positive-pressure ventilation, the use of noninvasive ventilation (NIV) through an interface substantially increased. The first technique was continuous positive airway pressure; but, after the introduction of pressure support ventilation at the end of the 20th century, this became the main modality. Both techniques, and some others that have been recently introduced and which integrate some technological innovations, have extensively demonstrated a faster improvement of acute respiratory failure in different patient populations, avoiding endotracheal intubation and facilitating the release of conventional invasive mechanical ventilation. In acute settings, NIV is currently the first-line treatment for moderate-to-severe chronic obstructive pulmonary disease exacerbation as well as for acute cardiogenic pulmonary edema and should be considered in immunocompromised patients with acute respiratory insufficiency, in difficult weaning, and in the prevention of postextubation failure. Alternatively, it can also be used in the postoperative period and in cases of pneumonia and asthma or as a palliative treatment. NIV is currently used in a wide range of acute settings, such as critical care and emergency departments, hospital wards, palliative or pediatric units, and in pre-hospital care. It is also used as a home care therapy in patients with chronic pulmonary or sleep disorders. The appropriate selection of patients and the adaptation to the technique are the keys to success. This review essentially analyzes the evidence of benefits of NIV in different populations with acute respiratory failure and describes the main modalities, new devices, and some practical aspects of the use of this technique.

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

BACKGROUND

This is an update of a systematic review previously published in 2008 about non-invasive positive pressure ventilation (NPPV). NPPV has been widely used to alleviate signs and symptoms of respiratory distress due to cardiogenic pulmonary oedema. NPPV prevents alveolar collapse and helps redistribute intra-alveolar fluid, improving pulmonary compliance and reducing the pressure of breathing.

OBJECTIVES

To determine the effectiveness and safety of NPPV in the treatment of adult patients with cardiogenic pulmonary oedema in its acute stage.

SEARCH METHODS

We searched the following databases on 20 April 2011: CENTRAL and DARE, (The Cochrane Library, Issue 2 of 4, 2011); MEDLINE (Ovid, 1950 to April 2011); EMBASE (Ovid, 1980 to April 2011); CINAHL (1982 to April 2011); and LILACS (1982 to April 2011). We also reviewed reference lists of included studies and contacted experts and equipment manufacturers. We did not apply language restrictions.

SELECTION CRITERIA

We selected blinded or unblinded randomised or quasi-randomised clinical trials, reporting on adult patients with acute or acute-on-chronic cardiogenic pulmonary oedema and where NPPV (continuous positive airway pressure (CPAP) or bilevel NPPV) plus standard medical care was compared with standard medical care alone.

DATA COLLECTION AND ANALYSIS

Two authors independently selected articles and abstracted data using a standardised data collection form. We evaluated study quality with emphasis on allocation concealment, sequence generation allocation, losses to follow-up, outcome assessors, selective outcome reporting and adherence to the intention-to-treat principle.

MAIN RESULTS

We included 32 studies (2916 participants), of generally low or uncertain risk of bias. Compared with standard medical care, NPPV significantly reduced hospital mortality (RR 0.66, 95% CI 0.48 to 0.89) and endotracheal intubation (RR 0.52, 95% CI 0.36 to 0.75). We found no difference in hospital length of stay with NPPV; however, intensive care unit stay was reduced by 1 day (WMD -0.89 days, 95% CI -1.33 to -0.45). Compared with standard medical care, we did not observe significant increases in the incidence of acute myocardial infarction with NPPV during its application (RR 1.24, 95% CI 0.79 to 1.95) or after (RR 0.70, 95% CI 0.11 to 4.26). We identified fewer adverse events with NPPV use (in particular progressive respiratory distress and neurological failure (coma)) when compared with standard medical care.

AUTHORS' CONCLUSIONS

NPPV in addition to standard medical care is an effective and safe intervention for the treatment of adult patients with acute cardiogenic pulmonary oedema. The evidence to date on the potential benefit of NPPV in reducing mortality is entirely derived from small-trials and further large-scale trials are needed.

Prehospital continuous positive airway pressure for acute respiratory failure: a systematic review and meta-analysis

INTRODUCTION

Acute respiratory failure (ARF) is a common problem encountered by emergency medical services and is associated with significant morbidity, mortality, and health care costs. Continuous positive airway pressure (CPAP) is an integral part of the hospital treatment of acute ARF, predominantly because of congestive heart failure. Intuitively, better patient outcomes may be achieved when CPAP is applied early in the prehospital setting, but there are few outcome studies to validate its use in this setting.

OBJECTIVE

This systematic review and meta-analysis aimed to examine the effectiveness of CPAP in the prehospital setting for patients with ARF.

METHODS

A literature review of bibliographic databases and secondary sources was conducted and potential papers were assessed by two independent reviewers. Included studies were those that compared CPAP therapy (and usual care) with no CPAP for ARF in the prehospital setting. Studies of other methods of noninvasive ventilation were not included. Methodologic quality was assessed using guidelines from the Cochrane Collaboration. Outcomes included the number of intubations, mortality, physiologic parameters, and dyspnea score. Forrest plots were constructed to estimate the pooled effect of CPAP on outcomes.

RESULTS

Five studies (1,002 patients) met the selection criteria--three randomized controlled trials (RCTs), a nonrandomized comparative study, and a retrospective comparative study using chart review. Forty-seven percent of the patients were allocated to the CPAP group. Baseline characteristics were similar between groups. The pooled estimates demonstrated significantly fewer intubations (odds ratio [OR] 0.31; 95% confidence interval [CI] 0.19-0.51) and lower mortality (OR 0.41; 95% CI 0.19-0.87) in the CPAP group.

CONCLUSION

The studies included in this review showed a reduction in the number of intubations and mortality in patients with ARF who received CPAP in the prehospital setting. The results may not be applicable to other health care contexts because of the inherent differences in the organization and staffing of the EMS systems. Information from large RCTs on the efficacy of CPAP initiated early in the prehospital setting is critical to establishing the evidence base underpinning this therapy before ambulance services incorporate CPAP as routine clinical practice.

Acute cardiogenic pulmonary oedema: reflecting on the management of an intensive care unit patient

AIM

The aim of this paper is to reflect upon the management interventions of non-invasive ventilation (NIV) and diuretic therapy that were implemented for a patient admitted to an intensive care unit (ICU) with acute cardiogenic pulmonary oedema.

BACKGROUND

Acute pulmonary oedema is a serious and life-threatening complication of acute heart failure, particularly if this results from an ischaemic event. Statistics highlight that of those patients treated for acute cardiogenic pulmonary oedema, approximately only one third were alive after 1 year. Many of these patients will require intensive care management in order to restore homeostasis. It is therefore imperative that nurses understand the condition and the relevant management of it in order to maximize the already poor prognosis.

RESULTS

Using Driscoll's (2000) reflective model to guide critical thinking, this paper reflects on the management of one patient who was admitted to ICU with acute cardiogenic pulmonary oedema as a result of heart failure. Although there are many aspects of patient management that can be explored, specific care interventions that this patient received in relation to NIV and diuretic therapy will be considered. The evidence base for their use, together with the relevant nursing management issues, and patient implications will be critically analysed and outlined.

CONCLUSIONS

This paper identifies that standard therapy for acute cardiogenic pulmonary oedema is largely supportive and aimed at promoting gaseous exchange. It also highlights that nurses have a key role in ensuring that these essential treatments are as efficacious as possible.

RELEVANCE TO CLINICAL PRACTICE

By using a reflective analysis approach, this paper highlights how reflecting on practice improves knowledge and understanding of the use of NIV and diuretic therapy interventions and should facilitate nurses working in ICU to become more competent in ensuring that the treatment provided for acute cardiogenic pulmonary oedema is as successful as possible.

Noninvasive positive pressure ventilation: resource document for the National Association of EMS Physicians position statement

The National Association of EMS Physicians (NAEMSP) believes that noninvasive positive pressure ventilation (NIPPV) is an important treatment modality for the prehospital management of acute dyspnea. This document serves as a resource to the NAEMSP position on prehospital NIPPV.

CPAP for acute cardiogenic pulmonary oedema from out-of-hospital to cardiac intensive care unit: a randomised multicentre study

PURPOSE

Continuous positive airway pressure (CPAP) is a useful treatment for patients with acute cardiogenic pulmonary oedema (CPE). However, its usefulness in the out-of-hospital setting has been poorly investigated and only by small and single-centre studies. We designed a multicentre randomised study to assess the benefit of CPAP initiated out of hospital.

METHODS

A total of 207 patients with CPE were randomly allocated by emergency mobile medical units to receive either standard treatment alone or standard treatment plus CPAP. CPAP was maintained after admission to the intensive care unit (ICU). Inclusion criteria were orthopnoea, respiratory rate greater than 25 breaths/min, pulse oximetry less than 90% in room air and diffuse crackles. The primary end point was assessed during the first 48 h and combined: death, presence of intubation criteria, persistence of either all inclusion criteria or circulatory failure at the second hour or their reappearance before 48 h. Absence of all criteria defined successful treatment.

RESULTS

CPAP was used for 60 min [40, 65] (median [Q1, Q3]) in the pre-hospital setting and 120 min [60, 242] in ICU and was well tolerated in all patients. Treatment was successful in 79% of patients in the CPAP group and 63% in the control group (p = 0.01), especially for persistence of inclusion criteria after 2 h (12 vs. 26%) and for intubation criteria (4 vs. 14%). CPAP was beneficial irrespective of the initial PaCO(2) or left ventricular ejection fraction.

CONCLUSION

Immediate use of CPAP in out-of-hospital treatment of CPE and until CPE resolves after admission significantly improves early outcome compared with medical treatment alone.

Acute heart failure: lessons learned so far

Acute heart failure (AHF) affects nearly every Canadian with heart failure (HF) at least once. Despite several attempts, no medical therapies have been shown to improve the natural history of AHF. In addition, the place of diagnosis of AHF is increasingly made in the outpatient setting. In this view, AHF is a moving target, and from recent registry data and from clinical trials, 5 critical lessons regarding the syndrome of AHF emerge: (1) The period of clinical instability preceding AHF may be much longer than previously thought. (2) Refinement of tools used to aid the early and accurate diagnosis of AHF will impact patient outcomes. (3) Standard supportive care of patients with AHF includes early use of diuretics with frequent reassessment in nearly all patients and supplemental vasodilators and oxygen therapy in selected cases. (4) Patients who survive presentation of AHF continue to suffer high rates of re-presentation, death, and rehospitalization following discharge from either hospital or emergency department. (5) Interventions shown to improve patient outcomes for AHF to date are related to process of care rather than new medications or devices. This report reviews the recent literature regarding the presentation, diagnosis, management, and prognosis of AHF. Areas of future research priority are indicated and guidelines for improving treatment are provided. AHF is an important clinical area that has not been as intensively studied as chronic HF; it presents both important needs and exciting opportunities for research and innovation.

Noninvasive ventilation in acute cardiogenic pulmonary edema: a meta-analysis of randomized controlled trials

BACKGROUND

The evidence of individual studies in acute cardiogenic pulmonary edema (ACPE) supporting noninvasive ventilation (NIV) is still inconclusive, particularly regarding noninvasive positive pressure ventilation (NIPPV).

METHODS

We carried out a meta-analysis. We searched in the Embase, Medline, Cinahl, Dare, Coch, Central, and CNKI databases and congress abstracts for trials comparing continuous positive airway pressure (CPAP) or NIPPV with standard therapy (ST). To assess treatment effects, we carried out direct comparison using a random effects model and adjusted indirect comparison.

RESULTS

At total of 34 studies (3,041 patients) were included. In direct comparisons, both CPAP and NIPPV reduced the risk of death (relative risk [RR] 0.64, 95% CI 0.44-0.93; RR 0.80, 95% CI 0.58-1.10; respectively) compared with ST, although only CPAP had a significant effect. There were no significant differences between NIPPV and CPAP. Pooled results of direct and adjusted indirect comparisons showed that compared with ST, both CPAP and NIPPV significantly reduced mortality (RR 0.63, 95% CI 0.44-0.89; RR 0.73, 95% CI 0.55-0.97; respectively).

CONCLUSIONS

Our findings suggest that among ACPE patients, NIV delivered through either NIPPV or CPAP reduced mortality.

The effects of continuous positive airway pressure on plasma brain natriuretic peptide concentrations in patients presenting with acute cardiogenic pulmonary edema with preserved left ventricular systolic function

BACKGROUND

It has been established that plasma brain natriuretic peptide (BNP) concentrations in patients with acute cardiogenic pulmonary edema (ACPE) increase in proportion to heart failure.

OBJECTIVES

The aim of this study is to assess the effects of continuous positive airway pressure (CPAP) treatment on plasma BNP concentrations in patients presenting with ACPE with preserved left ventricular (LV) systolic function.

METHODS

This was a prospective, observational single-center study in the emergency unit of Valduce Hospital. Twelve patients (group A) presenting with ACPE and preserved LV ejection fraction and 14 patients (group B) with systolic heart dysfunction (LV ejection fraction <45%) underwent CPAP (10 cm H(2)O) through a face mask and standard medical therapy. Plasma BNP concentrations were collected immediately before CPAP and 3, 6, and 24 hours after treatment. All patients underwent a morphological echocardiographic investigation shortly before CPAP.

RESULTS

Three hours after admission, BNP significantly decreased in patients with ACPE and preserved LVEF (from 998 + or - 467 pg/mL to 858 + or - 420 pg/mL; P < .05), whereas in those with systolic dysfunction, BNP was higher than during baseline (from 1352 + or - 473 pg/mL to 1570 + or - 595 pg/mL; P < .05).

CONCLUSIONS

The preliminary results of the present study show that CPAP, after 3 hours, lowers BNP levels in patients with ACPE and preserved LV systolic function compared with patients affected by systolic ACPE dysfunction where BNP levels do not change significantly.

The role of continuous positive airway pressure in acute cardiogenic edema with preserved left ventricular systolic function

OBJECTIVE

The objective of the study was to compare the effect of continuous positive airway pressure (CPAP) in patients with acute cardiogenic pulmonary edema (ACPE) with preserved or impaired left ventricular systolic function with regard to resolution time.

METHODS

In a prospective, preliminary observational cohort study, 18 patients with preserved left ventricular systolic function (group A) and 18 patients with systolic heart dysfunction (group B) with ACPE underwent CPAP (10 cmH(2)0) through a face mask with standard medical therapy after a morphologic echocardiographic investigation shortly before CPAP.

RESULTS

Resolution time did not differ significantly between the 2 groups of patients (64 +/- 25 minutes in diastolic group vs 80 +/- 33 minutes in systolic group). One patient in preserved left ventricular systolic function group required endotracheal intubation (not statistically significant). No patient died during hospital stay. Arterial blood gases improved after a trial of CPAP in both groups of patients.

CONCLUSIONS

The results of this preliminary study show that resolution time is not significantly different in patients with ACPE with preserved or impaired systolic function submitted to CPAP.

Continuous positive airway pressure vs. pressure support ventilation in acute cardiogenic pulmonary edema: a randomized trial

BACKGROUND

Both non-invasive continuous positive airway pressure (nCPAP) and non-invasive pressure support ventilation (nPSV) have been shown to be effective treatment for acute cardiogenic pulmonary edema (ACPE). In patients with severe ACPE who are treated with standard medical treatment, the baseline intubation rate is approximately 24%.

STUDY OBJECTIVE

This study was conducted to compare the endotracheal intubation (ETI) rate using two techniques, nCPAP vs. nPSV. In addition, mortality rate, improvement in gas exchange, duration of ventilation, and hospital length of stay were also assessed.

METHODS

This prospective, multi-center, randomized study enrolled 80 patients with ACPE who were randomized to receive nCPAP or nPSV (40 patients in each group) via an oronasal mask. Inclusion criteria were severe dyspnea, respiratory rate > 30 breaths/min, use of respiratory accessory muscles, or PaO(2)/FiO(2) < 200.

RESULTS

ETI was required in 0 (0%) and in 3 (7.5%) patients in the nCPAP group and in the nPSV group, respectively (p = 0.241). No significant difference was observed in in-hospital mortality: 2 (5%) vs. 7 (17.5%) in nCPAP and nPSV groups, respectively (p = 0.154). No difference in hospital length of stay was observed between the two groups, nor was there a difference observed in duration of ventilation, despite a trend for reduced time with nPSV vs. nCPAP (5.91 ± 4.01 vs. 8.46 ± 7.14 h, respectively, p = 0.052). Both nCPAP and nPSV were effective in improving gas exchange, including in the subgroup of hypercapnic patients.

CONCLUSIONS

Both methods are effective treatment for patients with ACPE. Non-invasive CPAP should be considered as the first line of treatment because it is easier to use and less expensive than non-invasive PSV.

Non-invasive ventilation in acute respiratory failure

Non-invasive mechanical ventilation has been increasingly used to avoid or serve as an alternative to intubation. Compared with medical therapy, and in some instances with invasive mechanical ventilation, it improves survival and reduces complications in selected patients with acute respiratory failure. The main indications are exacerbation of chronic obstructive pulmonary disease, cardiogenic pulmonary oedema, pulmonary infiltrates in immunocompromised patients, and weaning of previously intubated stable patients with chronic obstructive pulmonary disease. Furthermore, this technique can be used in postoperative patients or those with neurological diseases, to palliate symptoms in terminally ill patients, or to help with bronchoscopy; however further studies are needed in these situations before it can be regarded as first-line treatment. Non-invasive ventilation implemented as an alternative to intubation should be provided in an intensive care or high-dependency unit. When used to prevent intubation in otherwise stable patients it can be safely administered in an adequately staffed and monitored ward.

Noninvasive ventilation in acute cardiogenic pulmonary edema

PURPOSE OF REVIEW

Patients with acute pulmonary edema are often treated with noninvasive ventilation (NIV). There are essentially two modalities used in this setting: continuous positive airway pressure and bilevel pressure support ventilation. The clinical impact of these techniques and the subset of patients who can benefit from their application have not been definitely established.

RECENT FINDINGS

The main advantage of the use of NIV in patients with severe acute pulmonary edema is to avoid intubation by more effectively decreasing respiratory distress with respect to conventional oxygen therapy. These beneficial effects were demonstrated in three meta-analyses including nearly 900 patients. Although neither technique was superior to the other in the comparative analysis, a tendency to reduce hospital mortality was observed, which was statistically significant for continuous positive airway pressure. However, unpublished data from a large multicenter trial comparing both modalities of NIV to conventional treatment in emergency departments did not confirm these results. Recent research has pointed out a clear advantage when the treatment is initiated early in the prehospital setting.

SUMMARY

Although in acute pulmonary edema NIV is more effective in improving respiratory distress than conventional oxygen therapy and reduces the necessity of intubation, the subset of patients who can best benefit from these techniques in terms of mortality still warrant further investigation.

Current treatment options for early management in acute decompensated heart failure

Acute decompensated heart failure (ADHF) is a common syndrome that precedes over 100,000 hospitalizations in Canada per year (with length of stay in excess of six to eight days), making this the most costly disorder for patients older than 65 years of age. Over 85% of ADHF patients present with shortness of breath and exhibit evidence of volume overload. These findings may be variable in elderly patients, which complicates diagnosis. In fact, even in experienced centres, diagnostic accuracy is less than 80%. Despite advances in the treatment of chronic heart failure, meaningful improvements in outcomes associated with ADHF are very few. The basic assessment and treatments have not changed (early parenteral diuretics, electrocardiographic and oxygen saturation monitoring, supplemental oxygen administration). The introduction of measurement of natriuretic peptides in those in whom the diagnosis is uncertain may reduced the error rate by over 50%. The use of vasodilator therapy in the absence of cardiogenic shock can lead to earlier amelioration of symptoms, especially in those who do not respond to initial diuretics. Repeated monitoring of vital signs, body weight, electrolytes and creatinine levels is essential to minimize the risk of side effects of treatments. Noninvasive ventilation may reduce the need for endotracheal intubation in patients with severe ADHF and hypoxia at rest. Once the initial phase of heart failure treatment is completed, then the clinician should begin to focus on maximization of chronic heart failure therapy and discharge planning.

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

BACKGROUND

Non-invasive positive pressure ventilation (NPPV) has been widely used to alleviate signs and symptoms of respiratory distress due to cardiogenic pulmonary edema. NPPV prevents alveolar collapse and helps redistribute intra-alveolar fluid, improving pulmonary compliance and reducing the pressure of breathing.

OBJECTIVES

To determine the effectiveness and safety of NPPV in the treatment of adult patients with cardiogenic pulmonary edema.

SEARCH STRATEGY

We undertook a comprehensive search of the following databases in April 2005: CENTRAL, MEDLINE, EMBASE, CINAHL, DARE and LILACS. We also reviewed reference lists of included studies and contacted experts, equipment manufacturers, and the Cochrane Heart Group. We did not apply language restrictions.

SELECTION CRITERIA

We selected blinded or unblinded randomized or quasi-randomized clinical trials, reporting on adult patients with acute or acute-on-chronic cardiogenic pulmonary edema and where NPPV (continuous positive airway pressure (CPAP)) and/or bilevel NPPV plus standard medical care was compared with standard medical care alone.

DATA COLLECTION AND ANALYSIS

Two authors independently selected articles and abstracted data using a standardized data collection form. We evaluated study quality with emphasis on allocation concealment, adherence to the intention-to-treat principle and losses to follow-up.

MAIN RESULTS

We included 21 studies involving 1,071 participants. Compared to standard medical care, NPPV significantly reduced hospital mortality (RR 0.6, 95% CI 0.45 to 0.84) and endotracheal intubation (RR 0.53, 95% CI 0.34 to 0.83) with numbers needed to treat of 13 and 8, respectively. We found no difference in hospital length of stay with NPPV, however, intensive care unit stay was reduced by 1 day (WMD -1.07 days, 95% CI -1.60 to -0.53). Compared to standard medical care, we did not observe significant increases in the incidence of acute myocardial infarction with NPPV during (RR 1.24, 95% CI 0.79 to 1.95) or after (RR 0.82, 95% CI 0.09 to 7.54) its application.

AUTHORS' CONCLUSIONS

NPPV, especially CPAP, in addition to standard medical care is an effective and safe intervention for the treatment of adult patients with acute cardiogenic pulmonary edema.

Noninvasive ventilation in acute cardiogenic pulmonary edema

BACKGROUND

Noninvasive ventilation (continuous positive airway pressure [CPAP] or noninvasive intermittent positive-pressure ventilation [NIPPV]) appears to be of benefit in the immediate treatment of patients with acute cardiogenic pulmonary edema and may reduce mortality. We conducted a study to determine whether noninvasive ventilation reduces mortality and whether there are important differences in outcome associated with the method of treatment (CPAP or NIPPV).

METHODS

In a multicenter, open, prospective, randomized, controlled trial, patients were assigned to standard oxygen therapy, CPAP (5 to 15 cm of water), or NIPPV (inspiratory pressure, 8 to 20 cm of water; expiratory pressure, 4 to 10 cm of water). The primary end point for the comparison between noninvasive ventilation and standard oxygen therapy was death within 7 days after the initiation of treatment, and the primary end point for the comparison between NIPPV and CPAP was death or intubation within 7 days.

RESULTS

A total of 1069 patients (mean [+/-SD] age, 77.7+/-9.7 years; female sex, 56.9%) were assigned to standard oxygen therapy (367 patients), CPAP (346 patients), or NIPPV (356 patients). There was no significant difference in 7-day mortality between patients receiving standard oxygen therapy (9.8%) and those undergoing noninvasive ventilation (9.5%, P=0.87). There was no significant difference in the combined end point of death or intubation within 7 days between the two groups of patients undergoing noninvasive ventilation (11.7% for CPAP and 11.1% for NIPPV, P=0.81). As compared with standard oxygen therapy, noninvasive ventilation was associated with greater mean improvements at 1 hour after the beginning of treatment in patient-reported dyspnea (treatment difference, 0.7 on a visual-analogue scale ranging from 1 to 10; 95% confidence interval [CI], 0.2 to 1.3; P=0.008), heart rate (treatment difference, 4 beats per minute; 95% CI, 1 to 6; P=0.004), acidosis (treatment difference, pH 0.03; 95% CI, 0.02 to 0.04; P<0.001), and hypercapnia (treatment difference, 0.7 kPa [5.2 mm Hg]; 95% CI, 0.4 to 0.9; P<0.001). There were no treatment-related adverse events.

CONCLUSIONS

In patients with acute cardiogenic pulmonary edema, noninvasive ventilation induces a more rapid improvement in respiratory distress and metabolic disturbance than does standard oxygen therapy but has no effect on short-term mortality. (Current Controlled Trials number, ISRCTN07448447.)

Practical recommendations for prehospital and early in-hospital management of patients presenting with acute heart failure syndromes

Guideline recommendations for the prehospital and early in-hospital (first 6-12 hrs after presentation) management of acute heart failure syndromes are lacking. The American College of Cardiology/American Heart Association and European Society of Cardiology guidelines direct the management of these acute heart failure patients, but specific consensus on early management has not been published, primarily because few early management trials have been conducted. This article summarizes practical recommendations for the prehospital and early management of patients with acute heart failure syndromes; the recommendations were developed from a meeting of experts in cardiology, emergency medicine, and intensive care medicine from Europe and the United States. The recommendations are based on a unique clinical classification system considering the initial systolic blood pressure and other symptoms: 1) dyspnea and/or congestion with systolic blood pressure >140 mm Hg; 2) dyspnea and/or congestion with systolic blood pressure 100-140 mm Hg; 3) dyspnea and/or congestion with systolic blood pressure <100 mm Hg; 4) dyspnea and/or congestion with signs of acute coronary syndrome; and 5) isolated right ventricular failure. These practical recommendations are not intended to replace existing guidelines. Rather, they are meant to serve as a tool to facilitate guideline implementation where data are available and to provide suggested treatment approaches where formal guidelines and definitive evidence are lacking.

Simple lightweight disposable continuous positive airways pressure mask to effectively treat acute pulmonary oedema: randomized controlled trial

OBJECTIVE

To compare the novel Boussignac valve continuous positive airways pressure (CPAP) delivery mask and a standard closed-circuit Drager CF800 CPAP system in the management of acute pulmonary oedema (APO) patients.

METHODS

This was a randomized controlled trial whereby patients presenting to the ED with APO and who met the study criteria received either CPAP via the Boussignac valve system or from a standard Drager CF800. Baseline physiological and arterial gas data were recorded and repeated at 30 and 60 min after CPAP commenced. The primary outcome was mean change in pCO2 at 60 min between the two systems.

RESULTS

There were 39 evaluable patients (19 Boussignac, 20 Drager). The mean change in pCO2 at 60 min compared to baseline was similar in the two groups (Boussignac 0.9 kPa vs. Drager 1.2 kPa, mean difference -0.3; 95% CI -1.0-0.5, P=0.45). In addition, there were no significant differences at 60 min in regards to respiratory rate decrease, Boussignac 17.3/min versus Drager 19.6/min (mean difference 1.3; 95% CI -3.3-5.8, P=0.58) or peripheral SaO2 increase, Boussignac 10.7% versus Drager 14.6% (mean difference -3.9; 95% CI -9.9-2.1, P=0.19). There was no significant difference in disposition from the ED or the complication rate.

CONCLUSIONS

The Boussignac valve system may be an effective lightweight disposable method of delivering CPAP to patients with APO. It appears to perform as effectively as much larger, more expensive and less transportable equipment.

Cardiopulmonary interactions in patients with heart failure

PURPOSE OF REVIEW

The purpose of this review was to summarize recent findings concerning the consequences of cardiopulmonary interactions in acute cardiogenic pulmonary edema, weaning from mechanical ventilation and fluid-responsiveness assessment by respiratory variations of stroke volume.

RECENT FINDINGS

The efficacy of continuous or bilevel positive airway pressure in patients with acute cardiogenic pulmonary edema was strongly suggested by two recent meta-analyses. There is growing evidence to suggest that weaning-induced cardiac dysfunction and acute cardiogenic pulmonary edema could explain a large amount of liberation failure from mechanical ventilation. Despite a potential role for echocardiography and plasma measurements of B-type natriuretic peptide in demonstrating a cardiac origin to weaning failure, the demonstration of a significant increase in pulmonary-artery occlusion pressure during the weaning trial remains the gold standard for this purpose. In patients with heart failure there is no evidence for revisiting the reliability of the respiratory variation of stroke-volume surrogates to predict fluid responsiveness.

SUMMARY

For clinical practice, the knowledge of cardiopulmonary interactions is of paramount importance in understanding the crucial role of mechanical ventilation for treating patients with heart failure and, by contrast, the deleterious cardiovascular effects of weaning in patients with overt or hidden cardiac failure.

Management of acute pulmonary edema in the emergency department

Noninvasive ventilation (NIV) is a safe and effective technique that can prevent side effects and complications related to endotracheal intubation. Acute cardiogenic pulmonary edema is currently the second most common indication for NIV, mainly in emergency departments. In this article we examine recent literature related to the applications of NIV in the acute setting with regard to patients with acute cardiogenic pulmonary edema. In addition, we examine the epidemiology and the pathophysiology of acute heart failure.

B-type natriuretic peptide concentrations and myocardial dysfunction in critical illness

B-type natriuretic peptide (BNP) is the first biomarker of proven value in screening for left ventricular dysfunction. The availability of point-of-care testing has escalated clinical interest and the resultant research is defining a role for BNP in the investigation and treatment of critically ill patients. This review was undertaken with the aim of collecting and assimilating current evidence regarding the use of BNP assay in the evaluation of myocardial dysfunction in critically ill humans. The information is presented in a format based upon organ system and disease category. BNP assay has been studied in a spectrum of clinical conditions ranging from acute dyspnoea to subarachnoid haemorrhage. Its role in diagnosis, assessment of disease severity, risk stratification and prognostic evaluation of cardiac dysfunction appears promising, but requires further elaboration. The heterogeneity of the critically ill population appears to warrant a range of cut-off values. Research addressing progressive changes in BNP concentration is hindered by infrequent assay and appears unlikely to reflect the critically ill patient's rapidly changing haemodynamics. Multi-marker strategies may prove valuable in prognostication and evaluation of therapy in a greater variety of illnesses. Scant data exist regarding the use of BNP assay to alter therapy or outcome. It appears that BNP assay offers complementary information to conventional approaches for the evaluation of cardiac dysfunction. Continued research should augment the validity of BNP assay in the evaluation of myocardial function in patients with life-threatening illness.

The use of noninvasive ventilation in emergency department patients with acute cardiogenic pulmonary edema: a systematic review

STUDY OBJECTIVE

Acute cardiogenic pulmonary edema is a common cause of respiratory distress in emergency department (ED) patients. Noninvasive ventilation by noninvasive positive pressure ventilation or continuous positive airway pressure has been studied as a treatment strategy. We critically evaluate the evidence for the use of noninvasive ventilation on rates of hospital mortality and endotracheal intubation.

METHODS

We searched the databases of MEDLINE, EMBASE, and the Cochrane Library from 1980 to 2005. Additional sources included key journals, bibliographies of selected articles, and expert contact. We included studies that incorporated a randomized design; patients older than 18 years and with acute cardiogenic pulmonary edema; diagnosis and treatment initiated in the ED; noninvasive ventilation in addition to standard medical therapy compared to standard medical therapy alone, or noninvasive positive pressure ventilation compared to continuous positive airway pressure (both in addition to standard medical therapy); and data on hospital mortality or intubation. A random-effects model was used to obtain the summary risk ratios (RRs) and 95% confidence intervals (CIs) for hospital mortality and intubation.

RESULTS

A pooled analysis of 494 patients suggested that noninvasive ventilation in addition to standard medical therapy significantly reduced hospital mortality compared to standard medical therapy alone (RR 0.61; [95% CI 0.41, 0.91]). Similarly, a meta-analysis of 436 patients suggested that noninvasive ventilation was associated with a significant decrease in intubation rates (RR 0.43; [95% CI 0.21, 0.87]).

CONCLUSION

Our results suggest that noninvasive ventilation with standard medical therapy is advantageous over standard medical therapy alone in ED patients with acute cardiogenic pulmonary edema. Future studies, powered appropriately for mortality and intubation rates, are necessary to confirm these findings.

Effect of non-invasive positive pressure ventilation (NIPPV) on mortality in patients with acute cardiogenic pulmonary oedema: a meta-analysis

BACKGROUND

Non-invasive positive pressure ventilation (NIPPV), using continuous positive airway pressure (CPAP) or bilevel ventilation, has been shown to reduce the need for invasive mechanical ventilation in patients with acute cardiogenic pulmonary oedema. We assessed additional benefits of NIPPV in a meta-analysis.

METHODS

Meta-analysis comparison in acute cardiogenic pulmonary oedema was undertaken to compare (1) CPAP with standard therapy (oxygen by face-mask, diuretics, nitrates, and other supportive care), (2) bilevel ventilation with standard therapy, and (3) bilevel ventilation with CPAP, incorporating randomised controlled trials identified by electronic and hand search (1966-May, 2005). In 23 trials that fulfilled inclusion criteria, we assessed the effect of NIPPV on hospital mortality and mechanical ventilation, estimated as relative risks.

FINDINGS

CPAP was associated with a significantly lower mortality rate than standard therapy (relative risk 0.59, 95% CI 0.38-0.90, p=0.015). A non-significant trend towards reduced mortality was seen in the comparison between bilevel ventilation and standard therapy (0.63, 0.37-1.10, p=0.11). We recorded no substantial difference in mortality risk between bilevel ventilation and CPAP (p=0.38). The need for mechanical ventilation was reduced with CPAP (0.44, 0.29-0.66, p=0.0003) and with bilevel ventilation (0.50, 0.27-0.90, p=0.02), compared with standard therapy; but no significant difference was seen between CPAP and bilevel ventilation (p=0.86). Weak evidence of an increase in the incidence of new myocardial infarction with bilevel ventilation versus CPAP was recorded (1.49, 0.92-2.42, p=0.11). Heterogeneity of treatment effects was not evident for mortality or mechanical ventilation across patients' groups.

INTERPRETATION

In patients with acute cardiogenic pulmonary oedema, CPAP and bilevel ventilation reduces the need for subsequent mechanical ventilation. Compared with standard therapy, CPAP reduces mortality; our results also suggest a trend towards reduced mortality after bilevel NIPPV.

Non-invasive ventilation in acute cardiogenic pulmonary oedema

Non-invasive ventilation (NIV) is the delivery of assisted mechanical ventilation to the lungs, without the use of an invasive endotracheal airway. NIV has revolutionised the management of patients with various forms of respiratory failure. It has decreased the need for invasive mechanical ventilation and its attendant complications. Cardiogenic pulmonary oedema (CPO) is a common medical emergency, and NIV has been shown to improve both physiological and clinical outcomes. From the data presented herein, it is clear that there is sufficiently high level evidence to favour the use of continuous positive airway pressure (CPAP), and that the use of CPAP in patients with CPO decreases intubation rate and improves survival (number needed to treat seven and eight respectively). However, there is insufficient evidence to recommend the use of bilevel positive airway pressure (BiPAP), probably the exception being patients with hypercapnic CPO. More trials are required to conclusively define the role of BiPAP in CPO.

Efficacy and safety of non-invasive ventilation in the treatment of acute cardiogenic pulmonary edema--a systematic review and meta-analysis

INTRODUCTION

Continuous positive airway pressure ventilation (CPAP) and non-invasive positive pressure ventilation (NPPV) are accepted treatments in acute cardiogenic pulmonary edema (ACPE). However, it remains unclear whether NPPV is better than CPAP in reducing the need for endotracheal intubation (NETI) rates, mortality and other adverse events. Our aim was to review the evidence about the efficacy and safety of these two methods in ACPE management.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials on the effect of CPAP and/or NIPV in the treatment of ACPE, considering the outcomes NETI, mortality and incidence of acute myocardial infarction (AMI). We searched six electronic databases up to May 2005 without language restrictions, reviewed references of relevant articles, hand searched conference proceedings and contacted experts.

RESULTS

Of 790 articles identified, 17 were included. In a pooled analysis, 10 studies of CPAP compared to standard medical therapy (SMT) showed a significant 22% absolute risk reduction (ARR) in NETI (95% confidence interval (CI), -34% to -10%) and 13% in mortality (95%CI, -22% to -5%). Six studies of NPPV compared to SMT showed an 18% ARR in NETI (95%CI, -32% to -4%) and 7% in mortality (95%CI, -14% to 0%). Seven studies of NPPV compared to CPAP showed a non-significant 3% ARR in NETI (95%CI, -4% to 9%) and 2% in mortality (95%CI, -6% to 10%). None of these methods increased AMI risk. In a subgroup analysis, NPPV did not lead to better outcomes than CPAP in studies including more hypercapnic patients.

CONCLUSION

Robust evidence now supports the use of CPAP and NPPV in ACPE. Both techniques decrease NETI and mortality compared to SMT and none shows increased AMI risk. CPAP should be considered a first line intervention as NPPV did not show a better efficacy, even in patients with more severe conditions, and CPAP is cheaper and easier to implement in clinical practice.

Acutely decompensated congestive heart failure: new therapies for an old problem

Acutely decompensated heart failure is a common presentation to US emergency departments, and represents a major and increasing proportion of health burden. In contrast to chronic heart failure, where there have been numerous advances in care and corresponding decreases in morbidity and mortality, outcomes of patients with acutely decompensated heart failure have remained relatively unchanged with an approximate 10% 30-day mortality and almost 40% 1-year rehospitalization rate. This is reflected in the relative paucity of guidelines for this condition.

Noninvasive pressure support ventilation vs. continuous positive airway pressure in acute hypercapnic pulmonary edema

OBJECTIVE

This study compared noninvasive pressure support ventilation (NIPSV) and continuous positive airway pressure (CPAP) in patients with acute hypercapnic pulmonary edema with regard to resolution time.

DESIGN AND SETTING

Randomized prospective study in an emergency department.

PATIENTS AND PARTICIPANTS

We randomly assigned 36 patients with respiratory failure due to acute pulmonary edema and arterial hypercapnia (PaCO(2) >45 mmHg) to NIPSV (n=18) or CPAP through a face mask (n=18).

MEASUREMENTS AND RESULTS

Electrocardiographic and physiological measurements were made over 36 h. There was no difference in resolution time defined as clinical improvement with a respiratory rate of fewer than 30 breaths/min and SpO(2)of 96% or more between CPAP and NIPSV groups. Arterial carbon dioxide tension was significantly decreased after 1 h of ventilation (CPAP, 60.5+/-13.6 to 42.8+/-4.9 mmHg; NIPSV, 65.7+/-13.6 to 44.0+/-5.5 mmHg); respective improvements were seen in pH (CPAP, 7.22+/-0.11 to 7.37+/-0.04; NIPSV, 7.19+/-0.11 to 7.38+/-0.04), SpO(2) (CPAP, 86.9+/-3.7% to 95.1+/-2.6%; NIPSV, 83.7+/-6.6% to 96.0+/-2.9%), and respiratory rate (CPAP, 37.9+/-4.5 to 21.3+/-5.1 breaths/min; NIPSV, 39.8+/-4.4 to 21.2+/-4.6 breaths/min). No significant differences were seen with regards to endotracheal intubation and in-hospital mortality.

CONCLUSIONS

NIPSV proved as effective as CPAP in the treatment of patients with acute pulmonary edema and hypercapnia but did not improve resolution time.