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

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.

Noninvasive mechanical ventilation with average volume assured pressure support (AVAPS) in patients with chronic obstructive pulmonary disease and hypercapnic encephalopathy

BACKGROUND

Non-invasive mechanical ventilation (NIV) in patients with acute respiratory failure has been traditionally determined based on clinical assessment and changes in blood gases, with NIV support pressures manually adjusted by an operator. Bilevel positive airway pressure-spontaneous/timed (BiPAP S/T) with average volume assured pressure support (AVAPS) uses a fixed tidal volume that automatically adjusts to a patient's needs. Our study assessed the use of BiPAP S/T with AVAPS in patients with chronic obstructive pulmonary disease (COPD) and hypercapnic encephalopathy as compared to BiPAP S/T alone, upon immediate arrival in the Emergency-ICU.

METHODS

We carried out a prospective interventional match-controlled study in Guayaquil, Ecuador. A total of 22 patients were analyzed. Eleven with COPD exacerbations and hypercapnic encephalopathy with a Glasgow Coma Scale (GCS) <10 and a pH of 7.25-7.35 were assigned to receive NIV via BiPAP S/T with AVAPS. Eleven patients were selected as paired controls for the initial group by physicians who were unfamiliar with our study, and these patients were administered BiPAP S/T. Arterial blood gases, GCS, vital signs, and ventilatory parameters were then measured and compared between the two groups.

RESULTS

We observed statistically significant differences in favor of the BiPAP S/T + AVAPS group in GCS (P = .00001), pCO(2) (P = .03) and maximum inspiratory positive airway pressure (IPAP) (P = .005), among others. However, no significant differences in terms of length of stay or days on NIV were observed.

CONCLUSIONS

BiPAP S/T with AVAPS facilitates rapid recovery of consciousness when compared to traditional BiPAP S/T in patients with chronic obstructive pulmonary disease and hypercapnic encephalopathy.

TRIAL REGISTRATION

Current Controlled Trials application ref is ISRCTN05135218.

Critical airway skills and procedures

Airway management is a critical procedure and essential skill necessary for all physicians working in the emergency department. Optimal resuscitative treatment of medical and trauma patients often revolves around timely and effective airway interventions that can be challenging in the acute setting, especially in critical patients. Time-honored airway techniques and procedures combined with recent advances in rapid sequence intubation, video laryngoscopy, and further advanced airway techniques now offer emergency clinicians a wide range of exciting new options for improving this crucial component of acute care and management.

End-tidal arterial CO2 partial pressure gradient in patients with severe hypercapnia undergoing noninvasive ventilation

BACKGROUND

Patients with severe hypercapnia represent a particularly serious condition in an emergency department (ED), requiring immediate attention. Noninvasive ventilation (NIV) is an integral part of the treatment for acute respiratory failure. The present study aimed to validate the measurement of end-tidal CO2 (EtCO2) as a noninvasive technique to evaluate the effectiveness of NIV in acute hypercapnic respiratory failure.

METHODS

Twenty consecutive patients admitted to the ED with severe dyspnea were enrolled in the study. NIV by means of bilevel positive airway pressure, was applied to the patients simultaneously with standard medical therapy and continued for 12 hours; the arterial blood gases and side-stream nasal/oral EtCO2 were measured at subsequent times: T0 (admission to the ED), T1h (after 1 hour), T6h (after 6 hours), and T12h (after 12 hours) during NIV treatment.

RESULTS

The arterial CO2 partial pressure (PaCO2)-EtCO2 gradient decreased progressively, reaching at T6h and T12h values lower than baseline (P < 0.001), while arterial pH increased during the observation period (P < 0.001). A positive correlation was found between EtCO2 and PaCO2 values (r = 0.89, P < 0.001) at the end of the observation period.

CONCLUSION

In our hypercapnic patients, the effectiveness of the NIV was evidenced by the progressive reduction of the PaCO2-EtCO2 gradient. The measurement of the CO2 gradient could be a reliable method in monitoring the effectiveness of NIV in acute hypercapnic respiratory failure in the ED.

Noninvasive mechanical ventilation in chronic obstructive pulmonary disease and in acute cardiogenic pulmonary edema

Noninvasive ventilation (NIV) with conventional therapy improves the outcome of patients with acute respiratory failure due to hypercapnic decompensation of chronic obstructive pulmonary disease (COPD) or acute cardiogenic pulmonary edema (ACPE). This review summarizes the main effects of NIV in these pathologies. In COPD, NIV improves gas exchange and symptoms, reducing the need for endotracheal intubation, hospital mortality and hospital stay compared with conventional oxygen therapy. NIV may also avoid reintubation and may decrease the length of invasive mechanical ventilation. In ACPE, NIV accelerates the remission of symptoms and the normalization of blood gas parameters, reduces the need for endotracheal intubation, and is associated with a trend towards lesser mortality, without increasing the incidence of myocardial infarction. The ventilation modality used in ACPE does not affect the patient prognosis.

Management of critically ill patients receiving noninvasive and invasive mechanical ventilation in the emergency department

Patients requiring noninvasive and invasive ventilation frequently present to emergency departments, and may remain for prolonged periods due to constrained critical care services. Emergency clinicians often do not receive the same education on management of mechanical ventilation or have similar exposure to these patients as do their critical care colleagues. The aim of this review was to synthesize the evidence on management of patients requiring noninvasive and invasive ventilation in the emergency department including indications, clinical applications, monitoring priorities, and potential complications. Noninvasive ventilation is recommended for patients with acute exacerbation of chronic obstructive pulmonary disease or cardiogenic pulmonary edema. Less evidence supports its use in asthma and other causes of acute respiratory failure. Use of noninvasive ventilation in the prehospital setting is relatively new, and some evidence suggests benefit. Monitoring priorities for noninvasive ventilation include response to treatment, respiratory and hemodynamic stability, noninvasive ventilation tolerance, detection of noninvasive ventilation failure, and identification of air leaks around the interface. Application of injurious ventilation increases patient morbidity and mortality. Lung-protective ventilation with low tidal volumes based on determination of predicted body weight and control of plateau pressure has been shown to reduce mortality in patients with acute respiratory distress syndrome, and some evidence exists to suggest this strategy should be used in patients without lung injury. Monitoring of the invasively ventilated patient should focus on assessing response to mechanical ventilation and other interventions, and avoiding complications, such as ventilator-associated pneumonia. Several key aspects of management of noninvasive and invasively ventilated patients are discussed, with a particular emphasis on initiation and ongoing monitoring priorities focused on maintaining patient safety and improving patient outcomes.

H1N1 infection and acute respiratory failure: Can we give non-invasive ventilation a chance?

In 2009, a novel H1N1 Influenza virus has emerged and on June 11 the World Health Organization declared it as pandemic. It may cause acute respiratory failure ranging from severe Acute Respiratory Distress Syndrome to exacerbations of airflow limitation. Non-invasive ventilation is now considered first-line intervention for different causes of acute respiratory failure and may be considered in the context of H1N1 pandemic. Although infection control issues have been arisen, non-invasive ventilation was effective and safe during the Severe Acute Respiratory Syndrome in Asia. It is reasonable to recommend non-invasive ventilation in H1N1-related exacerbations of chronic respiratory diseases, especially in negative-pressure wards. Treatment of early Acute Respiratory Distress Syndrome associated with H1N1 using non-invasive ventilation could be tried rapidly identifying those who fail without delaying endotracheal intubation. Considering the high demand for critical care beds during the pandemic, non-invasive ventilation may have a role in reducing the estimated load.

[Evidence-based medicine: implications from the guideline "non-invasive ventilation" in critically ill elderly patients]

The demographic shift means that there are an increasing number of elderly critically ill patients with various comorbidities. This very specific group needs particular treatment which has not been considered sufficiently in medical guidelines so far. To improve health care, it is indispensable not only to work out the current guidelines, but aspects of geriatric medicine must also be integrated into future developments. Using the example of the recent guideline "non-invasive ventilation," it is shown how the process of designing and implication can actively be realized in clinical daily routine.

A case-based approach to noninvasive positive pressure ventilation

Noninvasive positive pressure ventilation (NIPPV) has revolutionized the concept of mechanical ventilation with the major benefit of avoiding invasive mechanical ventilation in specific situations, thereby preventing associated complications. Noninvasive positive pressure ventilation has emerged as the first line of management of hypercapnic respiratory failure (due to chronic obstructive pulmonary disease and neuromuscular weakness) and cardiogenic pulmonary edema in addition to standard therapy in the acute setting. There is improvement in gas exchange, relief of respiratory muscle fatigue, and clinical outcome with reduced morbidity and mortality. Nevertheless, contraindications and failures need to be identified early, as delaying endotracheal intubation is associated with increased morbidity and mortality. Despite overwhelming evidence to support its use, NIPPV is underused. Residents and hospitalists need to identify NIPPV as a treatment option in acute respiratory failure.

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.

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.

Efficacy of noninvasive positive pressure ventilation in elderly patients with acute hypercapnic respiratory failure

BACKGROUND

There have been no reports on the efficacy of noninvasive positive pressure ventilation (NPPV) in elderly patients.

OBJECTIVES

The purpose of this study was to clarify the efficacy and identify the predictors of a successful outcome of NPPV in patients over the age of 75 years with acute hypercapnic respiratory failure (AHRF).

METHODS

We retrospectively evaluated the data of 42 patients (21 men) with AHRF who were treated at our unit. The patients were divided into survivor and nonsurvivor groups, and the clinical parameters measured prior to the initiation of NPPV were compared between the 2 groups.

RESULTS

The mean age of the patients was 83.0 ± 6.3 years. The etiology of the respiratory failure was acute exacerbation of chronic obstructive pulmonary disease in 19 patients, acute cardiogenic pulmonary edema in 18 patients, idiopathic pulmonary fibrosis in 3 patients, sequelae of tuberculosis in 1 patient, and asthma in 1 patient. Of the 42 patients, 33 (78.6%) survived. All patients with a Glasgow Coma Scale (GCS) score ≥9 and/or an APACHE II score <29 survived after the initiation of NPPV.

CONCLUSION

An APACHE II score <29 and a GCS score ≥9 were predictors of a successful outcome of NPPV in elderly people.

Narrative review: the management of acute decompensated heart failure

Acute decompensated heart failure (ADHF) is the most common reason for hospitalization in Western nations. The prognosis of patients admitted to hospital with ADHF is poor, with up to 64% being readmitted within the first 90 days after discharge and with a 1-year mortality approximating 20%. Epidemiological studies suggest that the majority of patients hospitalized with ADHF receive treatment that is inadequate and which is not based on scientific evidence. Furthermore, emerging data suggest that the "conventional" therapeutic interventions for ADHF including morphine, high-dose diuretics, and inotropic agents may be harmful. The goal of this review is to provide evidence-based recommendations for the diagnosis and management of ADHF.

H1N1 infection and acute respiratory failure: can we give non-invasive ventilation a chance?

In 2009, a novel H1N1 Influenza virus has emerged and on June 11 the World Health Organization declared it as pandemic. It may cause acute respiratory failure ranging from severe Acute Respiratory Distress Syndrome to exacerbations of airflow limitation. Non-invasive ventilation is now considered first-line intervention for different causes of acute respiratory failure and may be considered in the context of H1N1 pandemic. Although infection control issues have been arisen, non-invasive ventilation was effective and safe during the Severe Acute Respiratory Syndrome in Asia. It is reasonable to recommend non-invasive ventilation in H1N1-related exacerbations of chronic respiratory diseases, especially in negative-pressure wards. Treatment of early Acute Respiratory Distress Syndrome associated with H1N1 using non-invasive ventilation could be tried rapidly identifying those who fail without delaying endotracheal intubation. Considering the high demand for critical care beds during the pandemic, non-invasive ventilation may have a role in reducing the estimated load.

Recent advances in the role of non-invasive ventilation in acute respiratory failure

Non-invasive positive pressure ventilation (NIPPV) is the technique of delivering mechanical ventilation without endotracheal intubation or tracheostomy. This is increasingly being utilised in both acute and chronic conditions. Strong evidence supports the use of NIPPV for acute respiratory failure (ARF) to prevent endotracheal intubation (ETI) and to facilitate extubation in patients with acute exacerbations of chronic obstructive pulmonary disease, to avoid ETI in acute cardiogenic pulmonary oedema (ACPO), and in immunocompromised patients. Weaker evidence supports the use of NIPPV for patients with ARF due to asthma exacerbations, with postoperative ARF, pneumonia and acute lung injury/acute respiratory distress syndrome. NIPPV should be applied under close monitoring for signs of treatment failure and, in such cases, ETI should be promptly available. A trained team, at an appropriate location, with careful patient selection and optimal choice of devices can optimise the outcome of NIPPV.

Predicting the success of noninvasive positive pressure ventilation in emergency room for patients with acute heart failure

BACKGROUND

Non-invasive positive pressure ventilation (NPPV) for acute heart failure (AHF) is increasingly used to avoid endotracheal intubation (ETI). We therefore reviewed our experience using respirator management in the emergency room for AHF, and evaluated the predictive factors in the success of NPPV in the emergency room.

METHODS AND RESULTS

Three-hundred forty-three patients with AHF were analyzed. The AHF patients were assigned to either BiPAP-Synchrony (B-S; Respironics, Merrysville, PA, USA) period (2005-2007, n = 176) or BiPAP-Vision (B-V; Respironics) period (2008-2010, n = 167). The rate of carperitide use was significantly increased and dopamine use was significantly decreased in the B-V period. The total length of hospital stay was significantly shorter in the B-V period. AHF patients were also assigned to a failed trial of NPPV followed by ETI (NPPV failure group) or an NPPV success group in the emergency room for each period. NPPV was successfully used in 48 cases in the B-S period, and in 111 cases in the B-V period. Fifty-seven ETI patients included 45 direct ETI and 11 NPPV failure cases in the B-S period, and 16 ETI patients included 10 direct ETI and 6 NPPV failure cases in the B-V period. The pH values were significantly lower in the NPPV failure than in the NPPV success for both periods (7.19 ± 0.10 vs. 7.28 ± 0.11, B-S period, p < 0.05; 7.05 ± 0.08 vs. 7.27 ± 0.14, B-V period, p < 0.001). A pH value of 7.20 produced the optimal balance in the B-S period, while that of 7.03 produced the optimal balance in B-V periods by the ROC curve analysis. The cutoff value of pH was lower in the B-V period than in the B-S period.

CONCLUSIONS

This predictive value provides successful estimates of NPPV with a high sensitivity and specificity, and the aortic blood gas level was above 7.03 pH when using the B-V system.

Non-invasive pressure support ventilation and CPAP in cardiogenic pulmonary edema: a multicenter randomized study in the emergency department

INTRODUCTION

Noninvasive pressure support ventilation (NIPSV) and continuous positive airway pressure (CPAP) are both advocated in the treatment of cardiogenic pulmonary edema (CPE); however, the superiority of one technique over the other has not been clearly demonstrated. With regard to its physiological effects, we hypothesized that NIPSV would be better than CPAP in terms of clinical benefit.

METHODS

In a prospective, randomized, controlled study performed in four emergency departments, 200 patients were assigned to CPAP (n = 101) or NIPSV (n = 99). Primary outcome was combined events of hospital death and tracheal intubation. Secondary outcomes included resolution time, myocardial infarction rate, and length of hospital stay. Separate analysis was performed in patients with hypercapnia and those with high B-type natriuretic peptide (>500 pg/ml).

RESULTS

Hospital death occurred in 5 (5.0%) patients receiving NIPSV and 3 (2.9%) patients receiving CPAP (p = 0.56). The need for intubation was observed in 6 (6%) patients in the NIPSV group and 4 (3.9%) patients in the CPAP group (p = 0.46). Combined events were similar in both groups. NIPSV was associated to a shorter resolution time compared to CPAP (159 ± 54 vs. 210 ± 73 min; p < 0.01), whereas the incidence of new myocardial infarction was not different between both groups. Similar results were found in hypercapnic patients and those with high B-type natriuretic peptide.

CONCLUSIONS

During CPE, NIPSV accelerates the improvement of respiratory failure compared to CPAP but does not affect primary clinical outcome either in overall population or in subgroups of patients with hypercapnia or those with high B-type natriuretic peptide.

Heart failure and the lung

Heart failure (HF) is a highly prevalent disease that leads to significant morbidity and mortality. There is increasing evidence that the symptoms of HF are exacerbated by its deleterious effects on lung function. HF appears to cause airway obstruction acutely and leads to impaired gas diffusing capacity and pulmonary hypertension in the longer term. It is postulated that this is the result of recurrent episodes of elevated pulmonary capillary pressure leading to pulmonary oedema and pulmonary capillary stress fracture, which produces lung fibrosis. It is likely that impaired lung function impairs the functional status of HF patients and makes them more prone to central sleep apnoea.

National Survey of the Use of Non-Invasive Respiratory Support for Acute Cardiogenic Pulmonary Oedema in Coronary Care Units in England

A telephone survey was conducted to assess the provision of non-invasive respiratory support available for the treatment of acute cardiogenic pulmonary oedema in England. Of 182 acute Trusts identified, data was obtained from 153 coronary care units (CCUs) (85%). At the time the survey was undertaken, more than a quarter of these CCUs did not have the facility to provide non-invasive respiratory support (NIRS) although these therapies were provided by the hospital intensive care units (ICUs) in 100% of hospitals that were contacted. In the CCUs providing non-invasive respiratory support, less than 20% audited their services; fewer than a third had a protocol for the management of acute cardiogenic pulmonary oedema and a management plan in the event of NIRS treatment failure — ie ‘do not resuscitate’ or escalation to higher levels of care — was mandatory in only 13% of units. This survey concludes that there is suboptimal provision of NIRS across CCUs in England adding to already heavily burdened critical care services. There is also widespread lack of clinical audit and management protocols, thus the effectiveness of available services is unknown.

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.

Weaning failure of cardiac origin: recent advances

This article is one of ten reviews selected from the Yearbook of Intensive Care and Emergency Medicine 2010 (Springer Verlag) and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/yearbook. Further information about the Yearbook of Intensive Care and Emergency Medicine is available from http://www.springer.com/series/2855.

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.

Review of non-invasive ventilation in the emergency department: clinical considerations and management priorities

AIMS AND OBJECTIVES

We aimed to synthesise evidence from published literature on non-invasive ventilation to inform nurses involved in the clinical management of non-invasive ventilation in the emergency department.

BACKGROUND

Non-invasive ventilation is a form of ventilatory support that does not require endotracheal intubation and is used in the early management of acute respiratory failure in emergency departments. Safe delivery of this intervention requires a skilled team, educated and experienced in appropriate patient selection, available devices and monitoring priorities.

DESIGN

Systematic review.

METHOD

A multi-database search was performed to identify works published in the English language between 1998-2008. Search terms included: non-invasive ventilation, continuous positive airway pressure and emergency department. Inclusion and exclusion criteria for the review were identified and systematically applied.

RESULTS

Terminology used to describe aspects of non-invasive ventilation is ambiguous. Two international guidelines inform the delivery of this intervention, however, much research has been undertaken since these publications. Strong evidence exists for non-invasive ventilation for patients with acute exacerbation of congestive heart failure and chronic obstructive pulmonary disease. Non-invasive ventilation may be delivered with various interfaces and modes; little evidence is available for the superiority of individual interfaces or modes.

CONCLUSIONS

Early use of non-invasive ventilation for the management of acute respiratory failure may reduce mortality and morbidity. Though international guidelines exist, specific recommendations to guide the selection of modes, settings or interfaces for various aetiologies are lacking due to the absence of empirical evidence.

RELEVANCE TO CLINICAL PRACTICE

Monitoring of non-invasive ventilation should focus on assessment of response to treatment, respiratory and haemodynamic stability, patient comfort and presence of air leaks. Complications are related to mask-fit and high air flows; serious complications are few and occur infrequently. The use of non-invasive ventilation has resource implications that must be considered to provide effective and safe management in the emergency department.

High flow biphasic positive airway pressure by helmet--effects on pressurization, tidal volume, carbon dioxide accumulation and noise exposure

INTRODUCTION

Non-invasive ventilation (NIV) with a helmet device is often associated with poor patient-ventilator synchrony and impaired carbon dioxide (CO2) removal, which might lead to failure. A possible solution is to use a high free flow system in combination with a time-cycled pressure valve placed into the expiratory circuit (HF-BiPAP). This system would be independent from triggering while providing a high flow to eliminate CO2.

METHODS

Conventional pressure support ventilation (PSV) and time-cycled biphasic pressure controlled ventilation (BiVent) delivered by an Intensive Care Unit ventilator were compared to HF-BiPAP in an in vitro lung model study. Variables included delta pressures of 5 and 15 cmH2O, respiratory rates of 15 and 30 breaths/min, inspiratory efforts (respiratory drive) of 2.5 and 10 cmH2O) and different lung characteristics. Additionally, CO2 removal and noise exposure were measured.

RESULTS

Pressurization during inspiration was more effective with pressure controlled modes compared to PSV (P < 0.001) at similar tidal volumes. During the expiratory phase, BiVent and HF-BiPAP led to an increase in pressure burden compared to PSV. This was especially true at higher upper pressures (P < 0.001). At high level of asynchrony both HF-BiPAP and BiVent were less effective. Only HF-BiPAP ventilation effectively removed CO2 (P < 0.001) during all settings. Noise exposure was higher during HF-BiPAP (P < 0.001).

CONCLUSIONS

This study demonstrates that in a lung model, the efficiency of NIV by helmet can be improved by using HF-BiPAP. However, it imposes a higher pressure during the expiratory phase. CO2 was almost completely removed with HF-BiPAP during all settings.

[Non-invasive ventilation as treatment for acute respiratory insufficiency. Essentials from the new S3 guidelines]

BACKGROUND

Scientific evidence is accumulating that non-invasive ventilation (NIV) may be beneficial for different patient groups with acute respiratory insufficiency (ARI). The aim of the new S3 guidelines is to propagate evidence-based knowledge about the indications and limitations of NIV in clinical practice.

METHODS

A total of 28 experts from 12 German medical societies were involved in the process of development of the present guidelines. These experts systematically analyzed approximately 2,900 publications. Finally, the recommendations were discussed and approved in two consensus conferences.

RESULTS

In hypercapnic ARI, NIV reduces the length of stay and mortality during intensive care treatment [grade A recommendation (A)]. Patients with cardiopulmonary edema should be treated with continuous positive airway pressure (CPAP) or NIV (A). For immunocompromized patients with ARI, NIV reduces the mortality (A). In patients with postextubation respiratory failure and during weaning from mechanical ventilation, NIV reduces the risk of reintubation (A). For patients who decline to be ventilated invasively, NIV may be an acceptable alternative (B). Non-invasive ventilation can also successfully be used in pediatric patients with ARI caused by different reasons (C). In acute respiratory distress syndrome (ARDS) NIV cannot generally be recommended because the failure rate is relatively high.

CONCLUSION

Non-invasive ventilation is still not as widely implemented in clinical medicine as would be expected on the basis of the scientific literature. The aim of the present guidelines is to further propagate NIV for the treatment of ARI.

Implementation of Boussignac continuous positive airway pressure in the coronary care unit: experiences and attitudes

OBJECTIVE

Boussignac continuous positive airway pressure (BCPAP) delivered by face mask is useful for patients with acute cardiogenic pulmonary edema (ACPE). Although BCPAP is medically effective, we observed that not all suitable patients received it. In this descriptive, prospective, cohort study, we explored the experiences and attitudes of both patients and staff with BCPAP.

METHODS

Patients were interviewed 12 to 48 hours after treatment with BCPAP. Nurses on the coronary care unit were interviewed on their knowledge, skills, experiences, and opinions concerning BCPAP.

RESULTS

Of 117 patients with ACPE, 87 patients (74%) received BCPAP treatment. It was decided not to administer BCPAP in 30 patients with ACPE (26%). Patients who received BCPAP found that the reduction of dyspnea outweighed any discomfort. Barriers for the use of BCPAP were not related to nurses' skills but to the following: the nurses' belief that BCPAP created major discomfort, the lack of guidelines, the ultimate improvement of oxygenation without BCPAP, and the more labor-intensive treatment.

CONCLUSION

Overestimation of patient discomfort by nurses and system-related factors impeded the use of BCPAP for all patients with ACPE.

Mortality in acute cardiogenic pulmonary edema treated with continuous positive airway pressure

OBJECTIVE

To investigate mortality in acute cardiogenic pulmonary edema (ACPE) patients treated with continuous positive airway pressure (CPAP) and to identify clinical and laboratory characteristics associated with mortality.

DESIGN

Observational, retrospective study.

SETTING

Emergency Medicine Department.

PATIENTS AND PARTICIPANTS

A total of 454 consecutive ACPE patients treated with CPAP.

MEASUREMENTS AND RESULTS

Demographics, past medical history, clinical characteristics, laboratory evaluation, in-hospital mortality data were collected. Potential predictors of in-hospital mortality that were considered of clinical relevance and immediately accessible on admission were investigated by multivariable logistic regression. ACPE-related mortality rate was 3.8% (17/452 patients) and the in-hospital mortality rate was 11.4% (50/440 patients). Significant independent predictors of increased risk of in-hospital mortality were: advanced age (P = 0.012), normal-to-low blood pressure (P < 0.001), low PaO(2)/FiO(2) ratio (P = 0.020), hypocapnia (P = 0.009) and anemia (P = 0.05).

CONCLUSIONS

Values recorded within few minutes from arrival to the hospital can predict mortality in ACPE patients treated with CPAP who has been tested, for the first time, in a real life study. This can allow physicians to quickly recognize more severe ACPE patients treated with CPAP and plan for aggressive monitoring and treatment and for deciding the better site of care.