The effect of positive pressure airway support on mortality and the need for intubation in cardiogenic pulmonary edema: a systematic review

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 outcomes in 2,430 acute decompensated heart failure patients: an ADHERE Registry Analysis

OBJECTIVES

Continuous or bilevel positive airway pressure ventilation, called noninvasive ventilation (NIV), is a controversial therapy for acute decompensated heart failure (ADHF). While NIV is considered safe and effective in patients with chronic obstructive pulmonary disease (COPD), clinical trial data that have addressed safety in ADHF patients are limited, with some suggestion of increased mortality. The objective of this study was to assess mortality outcomes associated with NIV and to determine if a failed trial of NIV followed by endotracheal intubation (ETI) (NIV failure) is associated with worse outcomes, compared to immediate ETI.

METHODS

This was a retrospective analysis of the Acute Decompensated Heart Failure National Registry (ADHERE), which enrolls patients with treatment for, or with a primary discharge diagnosis of, ADHF. The authors compared characteristics and outcomes in four groups: no ventilation, NIV success, NIV failure, and ETI. One-way analysis of variance or Wilcoxon testing was performed for continuous data, and chi-square tests were used for categorical data. In addition, multivariable logistic regression was used to adjust mortality comparisons for risk factors.

RESULTS

Entry criteria were met by 37,372 patients, of which 2,430 had ventilation assistance. Of the ventilation group, 1,688 (69.5%) were deemed NIV success, 72 (3.0%) were NIV failures, and 670 (27.6%) required ETI. The NIV failure group had the lowest O(2) saturation (SaO(2)) (84 +/- 16%), compared to either NIV success (89.6 +/- 10%) or ETI (88 +/- 13%; p = 0.017). ETI patients were more likely to receive vasoactive medications (p < 0.001) than the NIV success cohort. When comparing NIV failures to ETI, there were no differences in treatment during hospitalization (p > 0.05); other than that the NIV failure group more often received vasodilators (68.1% vs. 54.3%; p = 0.026). In-hospital mortality was 7.9% with NIV, 13.9% with NIV failure, and 15.4% with ETI. After risk adjustment, the mortality odds ratio for NIV failure versus ETI increased to 1.43, although this endpoint was not statistically significant.

CONCLUSIONS

In this analysis of ADHF patients receiving NIV to date, patients placed on NIV for ADHF fared better than patients requiring immediate ETI. Patients who failed NIV and required ETI still experienced lower mortality than those initially placed on ETI. Thus, while the ETI group may be more severely ill, starting therapy with NIV instead of immediate ETI will likely not harm the patient. When ETI is required, mortality and length of stay may be adversely affected. Since a successful trial of NIV is associated with improved outcomes in patients with ADHF, application of this therapy may be a reasonable treatment option.

Continuous negative extrathoracic pressure or continuous positive airway pressure for acute hypoxemic respiratory failure in children

BACKGROUND

Acute hypoxemic respiratory failure (AHRF) is an important cause of mortality and morbidity in children. Positive pressure ventilation is currently the standard care, however, it does have complications. Continuous negative extrathoracic pressure ventilation (CNEP) or continuous positive airway pressure (CPAP) ventilation delivered via non-invasive approaches (Ni-CPAP) have shown certain beneficial effects in animal and uncontrolled human studies.

OBJECTIVES

The primary objective was to assess the effectiveness of CNEP or Ni-CPAP in pediatric patients with AHRF from non-cardiogenic causes.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2007, Issue 3); MEDLINE (January 1966 to July 2007); EMBASE (1980 to July 2007); CINAHL (1982 to July 2007); and published abstracts from the meetings of the American Thoracic Society and Pediatric Critical Care Meetings (1992 to 2007).

SELECTION CRITERIA

Randomized or quasi-randomized clinical trials of either CNEP or Ni-CPAP versus standard therapy (including positive pressure ventilation) involving children (at least 1 month old and less than 18 years of age at the time of randomization) who met the criteria for diagnosis of AHRF with at least one of the outcomes reported were included.

DATA COLLECTION AND ANALYSIS

Risks of bias of the included study was assessed using: concealment of allocation, blinding of intervention, completeness of follow up and blinding of outcome measurements. Data on relevant outcomes were abstracted and the effect size was estimated by calculating relative risk (RR) with 95% confidence intervals (CI) and risk difference (RD).

MAIN RESULTS

One eligible study published in an abstract format was identified. It studied 33 infants (18 controls, 15 receiving CNEP) with a clinical diagnosis of bronchiolitis and fraction of inspired oxygen (FiO(2)) > 40% were studied. This allowed a reduction in the FiO(2) (< 30% within one hour of initiation of therapy) in four patients in the CNEP group compared to none in the control group (RR 10.7, 95% CI 0.6 to 183.9). One infant required CPAP and one infant required nasal CPAP in the control group while all infants in the CNEP group were managed without intubation (RR for both outcomes 0.40, 95% CI 0.02 to 9.06).

AUTHORS' CONCLUSIONS

There is a lack of well designed, controlled experiments of non-invasive modes of respiratory support in children with AHRF. Reduction of in-hospital mortality is an important outcome and even a small reduction would be beneficial. Studies assessing other outcomes such as avoidance of intubation and its associated complications, reduction in hospital stay and improvement in patient comfort are also valuable in gauging the overall impact of these strategies.

Noninvasive ventilation in the older patient who has acute respiratory failure

Older patients are at significantly increased risk of acute respiratory failure from multiple causes. Noninvasive positive pressure ventilation has been shown to dramatically improve care of patients with acute respiratory failure. Patient selection is important in all patients being treated with noninvasive positive pressure ventilation but is especially important in older patients. Delirium, confusion, and dementia can lead to difficulty for patients in tolerating this procedure and lead to a worsening respiratory status. The presence of a do-not-intubate order does not necessarily preclude the use of noninvasive positive pressure ventilation, and some patients may derive significant benefit from its use. Overall, noninvasive positive pressure ventilation is a reasonable and justifiable option in the treatment of acute respiratory failure in older patients.

Noninvasive ventilation in acute respiratory failure

BACKGROUND

Noninvasive ventilation has assumed an important role in the management of respiratory failure in critical care units, but it must be used selectively depending on the patient's diagnosis and clinical characteristics.

DATA

We review the strong evidence supporting the use of noninvasive ventilation for acute respiratory failure to prevent intubation in patients with chronic obstructive pulmonary disease exacerbations or acute cardiogenic pulmonary edema, and in immunocompromised patients, as well as to facilitate extubation in patients with chronic obstructive pulmonary disease who require initial intubation. Weaker evidence supports consideration of noninvasive ventilation for chronic obstructive pulmonary disease patients with postoperative or postextubation respiratory failure; patients with acute respiratory failure due to asthma exacerbations, pneumonia, acute lung injury, or acute respiratory distress syndrome; during bronchoscopy; or as a means of preoxygenation before intubation in critically ill patients with severe hypoxemia.

CONCLUSION

Noninvasive ventilation has assumed an important role in managing patients with acute respiratory failure. Patients should be monitored closely for signs of noninvasive ventilation failure and promptly intubated before a crisis develops. The application of noninvasive ventilation by a trained and experienced intensive care unit team, with careful patient selection, should optimize patient outcomes.

Noninvasive ventilation for critical care

Noninvasive ventilation (NIV), the provision of ventilatory assistance without an artificial airway, has emerged as an important ventilatory modality in critical care. This has been fueled by evidence demonstrating improved outcomes in patients with respiratory failure due to COPD exacerbations, acute cardiogenic pulmonary edema, or immunocompromised states, and when NIV is used to facilitate extubation in COPD patients with failed spontaneous breathing trials. Numerous other applications are supported by weaker evidence. A trial of NIV is justified in patients with acute respiratory failure due to asthma exacerbations and postoperative states, extubation failure, hypoxemic respiratory failure, or a do-not-intubate status. Patients must be carefully selected according to available guidelines and clinical judgment, taking into account risk factors for NIV failure. Patients begun on NIV should be monitored closely in an ICU or other suitable setting until adequately stabilized, paying attention not only to vital signs and gas exchange, but also to comfort and tolerance. Patients not having a favorable initial response to NIV should be considered for intubation without delay. NIV is currently used in only a select minority of patients with acute respiratory failure, but with technical advances and new evidence on its proper application, this role is likely to further expand.

Continuous positive airway pressure versus bilevel noninvasive ventilation in acute cardiogenic pulmonary edema: a randomized multicenter trial

STUDY OBJECTIVE

Patients with acute cardiogenic pulmonary edema may develop respiratory failure. Noninvasive respiratory support should be initiated rapidly to avoid tracheal intubation. The aim of this study is to compare the efficacy of continuous positive airway pressure (CPAP) delivered by the Boussignac CPAP device and bilevel positive airway pressure (bilevel PAP) in patients with acute respiratory failure caused by acute cardiogenic pulmonary edema.

METHODS

This prospective multicenter randomized study was conducted in 3 emergency departments. Patients were assigned to Boussignac CPAP through a facemask or to bilevel PAP, in addition to standard therapy. The main outcome was a combined criterion (tracheal intubation, death, or acute myocardial infarction). Complications, durations of ventilation, and hospitalization were also assessed.

RESULTS

After 1 hour of ventilation and at the end of the ventilation period, clinical parameters of respiratory distress and blood gas exchange significantly improved in each treatment arm. No significant differences were observed between the Boussignac CPAP and bilevel PAP arms for the combined criterion (5% versus 12%, respectively; odds ratio [OR] 0.4; 95% confidence interval [CI] 0.0 to 1.9) and also for severe complications (9% versus 6%; OR 1.5; 95% CI 0.3 to 9.9), duration of ventilation (median for both groups 2 hours; interquartile range [IQR] 1.2 to 3.0 hours), duration of hospitalization (CPAP 8.5 [IQR 6 to 14] days; bilevel PAP 10 [IQR 7 to 16] days), or intrahospital mortality (8% versus 14%; OR 1.8 [IQR 0.4 to 8.8]). Similar results were obtained among hypercapnic patients (PaCO2 >45 mm Hg). Whatever the ventilation support used, the combined criterion and severe complications were more frequently observed among hypercapnic patients.

CONCLUSION

Both Boussignac CPAP and bilevel PAP appeared effective in rapidly improving respiratory distress even in hypercapnic patients, but they were not different in terms of patient outcome.

Treatment of Severe Decompensated Heart Failure With High-Dose Intravenous Nitroglycerin: A Feasibility and Outcome Analysis

STUDY OBJECTIVE

We perform a feasibility and outcome assessment of the treatment of severe decompensated heart failure with high-dose nitroglycerin.

METHODS

This study was designed as a nonrandomized, open-label, single-arm study of high-dose nitroglycerin. Patients with hypertension (systolic blood pressure > or = 160 mm Hg or mean arterial pressure > or = 120 mm Hg) who were refractory to initial therapy were eligible for inclusion. Enrolled patients began receiving a titratable nitroglycerin infusion and were given a bolus of high-dose nitroglycerin (2 mg). Repeated administration of high-dose nitroglycerin was allowed every 3 minutes, up to a total of 10 doses. Predefined effectiveness and safety outcomes were tracked throughout hospital admission. To provide a frame of reference for these outcomes, data were retrospectively compiled for similar patients with severe decompensated heart failure who did not receive high-dose nitroglycerin.

RESULTS

Twenty-nine patients received high-dose nitroglycerin. Endotracheal intubation was required in 13.8% of patients, bilevel positive airway pressure (BiPAP) ventilation in 6.9%, and ICU admission in 37.9%. Symptomatic hypotension developed in 1 patient (3.4%), and biomarker evidence of myocardial infarction was found in 17.2% of patients. The mean dose of high-dose nitroglycerin was 6.5 mg (+/-3.4). For patients who were treated without high-dose nitroglycerin (n=45), endotracheal intubation occurred in 26.7%, BiPAP in 20.0%, and ICU admission in 80.0%. None of these patients developed symptomatic hypotension, and biomarker evidence of myocardial infarction was observed in 28.9% of patients.

CONCLUSION

In this nonrandomized, open-label trial, high-dose nitroglycerin was associated with endotracheal intubation, BiPAP, and ICU admission less frequently than expected to occur without high-dose nitroglycerin, and adverse events were uncommon. Treatment of hypertensive, severely decompensated heart failure patients with high-dose nitroglycerin seems promising, but a randomized, blinded study is needed to more completely define its clinical utility. According to this trial, such a study seems feasible.

Noninvasive ventilation in patients with hypoxemic acute respiratory failure

PURPOSE OF REVIEW

To discuss the recent literature concerning the use of noninvasive ventilation for hypoxemic acute respiratory failure.

RECENT FINDINGS

The benefits of noninvasive ventilation for patients with hypoxemic acute respiratory failure are unclear. In immunocompromised patients and following thoracic surgery, there is a strong rationale for using noninvasive ventilation to treat acute respiratory failure. Prophylactic continuous positive airway pressure after abdominal or thoracic surgery and prophylactic noninvasive ventilation in patients at risk of extubation failure have proved beneficial. Recent studies show that noninvasive ventilation has a favourable impact in immunocompetent patients with acute lung injury/acute respiratory distress syndrome, but caution is required. In hypoxemic acute respiratory failure after extubation, one study reported excess mortality in patients treated with noninvasive ventilation, possibly related to the delay for intubation. A major issue is avoiding undue noninvasive ventilation prolongation and staying alert for predictors of early noninvasive ventilation failure. Caution, close monitoring, and broad experience are required.

SUMMARY

Hypoxemic acute respiratory failure may benefit from noninvasive ventilation or continuous positive airway pressure, but undue prolongation should be avoided. In postextubation respiratory failure there is no evidence for routine use of noninvasive ventilation.

[Non-invasive ventilation]

Non-invasive ventilation is a technique to ventilate patients without endotracheal intubation and analgosedation. Pressure tight masks allow the ventilation of patients with severe respiratory or ventilatory insufficiency. Non-invasive ventilation may be used as short-term treatment for patients with acute ventilatory decompensation, as well as for long-term therapy at home for patients with chronic respiratory diseases. The typical indications are hypoxaemic respiratory failure in pneumonia or cardiogenic pulmonary edema, and hypercapnic ventilatory insufficiency in severe chronic obstructive pulmonary disease, neuromuscular disorders, or advanced kyphoscoliosis. The physiological background, technical aspects of performing non-invasive ventilation, and typical indications are discussed.

Basic ventilator management: lung protective strategies

Acute respiratory failure is manifested clinically as a patient with variable degrees of respiratory distress, but characteristically an abnormal arterial blood partial pressure of oxygen or carbon dioxide. The application of mechanical ventilation in this setting can be life-saving. An emerging body of clinical and basic research, however, has highlighted the potential adverse effects of positive pressure ventilation. Clinicians involved with the care of critically ill patients must recognize and seek to prevent these complications using lung-protective ventilation strategies. This article discusses the basic concepts of mechanical ventilation, reviews the categories of ventilator-associated lung injury, and discusses current strategies for the recognition and prevention of these adverse effects in the application of mechanical ventilation.

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.

Effectiveness of prehospital continuous positive airway pressure in the management of acute pulmonary edema

OBJECTIVE

To compare the effectiveness of continuous positive airway pressure (CPAP) with standard pharmacologic treatment in the management of prehospital acute pulmonary edema.

METHODS

Using a nonrandomized control group design, all consecutive patients presenting to two participating emergency medical services (EMS) systems with a field impression of acute pulmonary edema between July 1, 2004, and June 30, 2005, were included in the study. The control EMS system patients received standard treatment with oxygen, nitrates, furosemide, morphine, and, if indicated, endotracheal intubation. The intervention EMS system patients received CPAP via face mask at 10 cm H2O in addition to standard therapy.

RESULTS

Ninety-five patients received standard therapy, and 120 patients received CPAP and standard therapy. Intubation was required in 8.9% of CPAP-treated patients compared with 25.3% in the control group (p = 0.003), and mortality was lower in the CPAP group than in the control group (5.4% vs. 23.2%; p = 0.000). When compared with the control group, the CPAP group had more improvement in respiratory rate (-4.55 vs. -1.81; p = 0.001), pulse rate (-4.77 vs. 0.82; p = 0.013), and dyspnea score (-2.11 vs. -1.36; p = 0.008). Using logistic regression to control for potential confounders, patients receiving standard treatment were more likely to be intubated (odds ratio, 4.04; 95% confidence interval, 1.64 to 9.95) and more likely to die (odds ratio, 7.48; 95% confidence interval, 1.96 to 28.54) than those receiving standard therapy and CPAP.

CONCLUSION

The prehospital use of CPAP is feasible, may avert the need for endotracheal intubation, and may reduce short-term mortality.

Non-invasive positive pressure ventilation in acute respiratory failure: providing competent care

Non-invasive positive pressure ventilation (NPPV) has been used as an alternative strategy to provide ventilatory support for patients with acute respiratory failure. Most studies demonstrate that the use of NPPV in acute respiratory failure results in a reduction in the need for endotracheal intubation and an overall survival advantage. However, current evidence, in the form of randomised controlled trials, suggests that these benefits may be restricted to patients suffering from acute exacerbation of chronic obstructive pulmonary disease (COPD). The clinical application of NPPV involves the development of competence in delivering the particular intervention. Clinical outcomes and thus valid comparisons with alternate methods of ventilatory support can only be made if attention is paid to the clinical indications for the application of NPPV and patient subgroups it is used to treat and the level of competence of care givers in its application and delivery. One essential element of competence is the establishment of an appropriate knowledge base and the development of clinical practice guidelines. This literature review identifies the current indications for NPPV and the relevant information for developing clinical practice guidelines for the management of this form of ventilatory support.

Management of acute ventilatory failure

Acute ventilatory failure is a challenging yet increasingly common medical emergency reflecting the growing burden of respiratory disease. It is not a diagnosis in itself but the end result of a diversity of disease processes culminating in arterial hypoxaemia and hypercapnia. This review focuses on key management issues including giving appropriate oxygen therapy, treatment of the underlying aetiology as well as any precipitant factors and provision of assisted ventilation if required. Ventilatory assistance can be provided both invasively and non-invasively and the indications for either or both forms of assisted ventilation are discussed. Further emphasis is needed regarding advanced directives of care and clinicians should be aware of ethical issues regarding assisted ventilation.

Failure of non-invasive ventilation in patients with acute lung injury: observational cohort study

Introduction

The role of non-invasive positive pressure ventilation (NIPPV) in the treatment of acute lung injury (ALI) is controversial. We sought to assess the outcome of ALI that was initially treated with NIPPV and to identify specific risk factors for NIPPV failure.

Methods

In this observational cohort study at the two intensive care units of a tertiary center, we identified consecutive patients with ALI who were initially treated with NIPPV. Data on demographics, APACHE III scores, degree of hypoxemia, ALI risk factors and NIPPV respiratory parameters were recorded. Univariate and multivariate regression analyses were performed to identify risk factors for NIPPV failure.

Results

Of 79 consecutive patients who met the inclusion criteria, 23 were excluded because of a do not resuscitate order and two did not give research authorization. Of the remaining 54 patients, 38 (70.3%) failed NIPPV, among them all 19 patients with shock. In a stepwise logistic regression restricted to patients without shock, metabolic acidosis (odds ratio 1.27, 95% confidence interval (CI) 1.03 to 0.07 per unit of base deficit) and severe hypoxemia (odds ratio 1.03, 95%CI 1.01 to 1.05 per unit decrease in ratio of arterial partial pressure of O₂ and inspired O₂ concentration – PaO₂/FiO₂) predicted NIPPV failure. In patients who failed NIPPV, the observed mortality was higher than APACHE predicted mortality (68% versus 39%, p < 0.01).

Conclusion

NIPPV should be tried very cautiously or not at all in patients with ALI who have shock, metabolic acidosis or profound hypoxemia.

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.

Unilateral pulmonary oedema due to lung re-expansion following pleurocentesis for spontaneous pneumothorax. The role of non-invasive continuous positive airway pressure ventilation

Re-expansion pulmonary oedema represents a rare complication of treatment of spontaneous pneumothorax with only a few cases documented in the current literature. We present the case of a 47-year-old male who presented a right-sided spontaneous pneumothorax and developed respiratory failure after chest tube drainage. The diagnosis of re-expansion pulmonary oedema was made and he was successfully treated with non-invasive continuous positive airway pressure ventilation. Since pathogenesis of re-expansion unilateral pulmonary oedema differs significantly from that of cardiogenic pulmonary oedema, the role of non-invasive continuous positive airway pressure ventilation is discussed as an additional therapeutic option.

Non-invasive ventilation as a first-line treatment for acute respiratory failure: "real life" experience in the emergency department

OBJECTIVE

To describe our experience with non-invasive ventilation (NIV) for patients with acute respiratory failure (ARF) in the emergency department (ED).

METHODS

A prospective/retrospective, observational study on 190 patients with ARF (mean +/-SD age 72.2+/-12.9 years, mean APACHE II score 18.9+/-5.9), who received 200 NIV trials in an ED. We analysed the NIV register data (prospectively collected) and medical records (retrospective data abstraction) and evaluated clinical indications for NIV, patient outcomes, and predictive factors for success and death. NIV success was defined as tolerance of the procedure and no need for endotracheal intubation (ETI).

RESULTS

Main indications to NIV were cardiogenic pulmonary oedema (CPE) (70 trials), acute exacerbation of COPD (39), both CPE and acute exacerbation of COPD (11), pneumonia (48), decompensation of obesity/hypoventilation (6), other conditions (26). The procedure was successful in 60.5% of trials. Global mortality was 34.5%, similar to the APACHE II predicted mortality of 32%. ETI rates were 6.5% and tracheostomy rates 1%. The improvement of pH within six hours after NIV initiation was predictive of survival in the hypercapnic group.

CONCLUSIONS

Our results confirm the global efficacy of NIV in an ED setting, and show that, in spite of lower success rate in "real practice" in comparison with RCTs, an intermediate care unit can represent an appropriate and less expensive setting to perform this technique. The low rate of ETI seems to be because of the high number of patients for whom NIV was used as "ceiling" treatment.

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.

Canadian Cardiovascular Society consensus conference recommendations on heart failure 2006: diagnosis and management

Heart failure remains a common diagnosis, especially in older individuals. It continues to be associated with significant morbidity and mortality, but major advances in both diagnosis and management have occurred and will continue to improve symptoms and other outcomes in patients. The Canadian Cardiovascular Society published its first consensus conference recommendations on the diagnosis and management of heart failure in 1994, followed by two brief updates, and reconvened this consensus conference to provide a comprehensive review of current knowledge and management strategies. New clinical trial evidence and meta-analyses were critically reviewed by a multidisciplinary primary panel who developed both recommendations and practical tips, which were reviewed by a secondary panel. The resulting document is intended to provide practical advice for specialists, family physicians, nurses, pharmacists and others who are involved in the care of heart failure patients. Management of heart failure begins with an accurate diagnosis, and requires rational combination drug therapy, individualization of care for each patient (based on their symptoms, clinical presentation and disease severity), appropriate mechanical interventions including revascularization and devices, collaborative efforts among health care professionals, and education and cooperation of the patient and their immediate caregivers. The goal is to translate best evidence-based therapies into clinical practice with a measureable impact on the health of heart failure patients in Canada.

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.

Modern Management of Cardiogenic Pulmonary Edema

Cardiogenic pulmonary edema (CPE) is a life-threatening condition that is frequently encountered in standard emergency medicine practice. Traditionally, diagnosis was based on physical assessment and chest radiography and treatment focused on the use of morphine sulfate and diuretics. Numerous advances in diagnosis and treatment have been made, however. Serum testing for B-type natriuretic peptide (BNP) has improved the accuracy of diagnoses in these patients. Treatment should focus on fluid redistribution with aggressive preload and afterload reduction rather than simply on diuresis. Some specific medications and noninvasive positive pressure ventilation have been shown to be safe and rapidly effective in improving patients' symptoms and improve outcomes.

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.

Continuous negative extrathoracic pressure or continuous positive airway pressure for acute hypoxemic respiratory failure in children

BACKGROUND

Acute hypoxemic respiratory failure (AHRF) is an important cause of mortality and morbidity in the pediatric age group. Positive pressure ventilation is currently the standard of care, though is known to be associated with complications. Continuous negative extrathoracic pressure ventilation (CNEP) or continuous positive airway pressure ventilation delivered via non-invasive approaches (Ni-CPAP) have shown certain beneficial effects in animal and uncontrolled human studies.

OBJECTIVES

The primary objective of this review was to assess the effectiveness of CNEP and Ni-CPAP in pediatric patients with AHRF due to non-cardiogenic causes.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2005); MEDLINE (January 1966 to March 2005); EMBASE (1980 to March 2005); CINAHL (1982 to March 2005); published abstracts from the meetings of the American Thoracic Society and Pediatric Critical Care Meetings (1992 to 2005); and bibliographies of identified articles and asking the experts in the field.

SELECTION CRITERIA

Randomized or quasi-randomized clinical trials of either CNEP or Ni-CPAP versus standard therapy (positive pressure ventilation) involving children (at least 1 month old and less than 18 years of age at the time of randomization) who met the criteria for diagnosis of AHRF with at least one of the outcomes reported were included.

DATA COLLECTION AND ANALYSIS

The methodological quality of included study was assessed using the following criteria: concealment of randomization, blinding of intervention, completeness of follow up and blinding of outcome measurements. Data on relevant outcomes were abstracted and the effect size was estimated by calculating relative risk (RR) with 95% confidence intervals (CI) and risk difference (95% CI).

MAIN RESULTS

One eligible study was identified which was published in abstract format. Thirty-three infants (18 in the control group and 15 in the CNEP group) with a clinical diagnosis of bronchiolitis and fraction of inspired oxygen (FiO(2))()greater than 40% were studied. There was reduction in the FiO(2) (less than 30% within one hour of initiation of therapy) in four patients in the CNEP group compared to none in the control group (RR 10.7, 95% CI 0.6 to 183.9). One infant required positive pressure ventilation and one infant required nasal CPAP in the control group while all infants in the CNEP group were managed without intubation (RR for both outcomes 0.40, 95% CI 0.02 to 9.06).

IMPLICATION FOR PRACTICE

There is a lack of well designed, controlled experiments of noninvasive modes of respiratory support in children with AHRF. Implication for research: Reduction of in-hospital mortality is an important outcome and even a small reduction could be beneficial. Studies assessing other outcomes such as avoidance of intubation and its associated complications, reduction in hospital stay and improvement in patient comfort are also valuable in gauging the overall impact of these strategies.

Bilevel noninvasive positive pressure ventilation for acute respiratory failure: Survey of Ontario practice*

OBJECTIVE

To determine physicians' stated practices regarding the use of bilevel noninvasive ventilation (NIV) for acute respiratory failure and the predictors of practice variation.

DESIGN

Cross-sectional postal survey.

SETTING

Province of Ontario, Canada.

PARTICIPANTS

Attending physicians and residents in four specialties at 15 teaching hospitals.

INTERVENTIONS

We used literature searches and focus groups to design questions related to NIV utilization with respect to frequency, location of and indications for use, awareness of supporting literature, and perceived efficacy. We assessed the survey's clinical sensibility and reliability. We used regression analyses to evaluate practice variation among hospitals and specialties and to determine predictors of more frequent NIV use, initiation of and continued use in nonmonitored settings, and use for specific indications.

MEASUREMENTS AND MAIN RESULTS

Three hundred eighty-five (48%) of 808 physicians responded; 242 used NIV. The two most common indications for NIV use were chronic obstructive pulmonary disease and congestive heart failure. NIV guidelines, protocols, or policies were available in 12 of 15 hospitals. We found variation in NIV utilization among specialties but not hospitals. Specialty (critical care and respirology versus internal and emergency medicine), fewer years of postgraduate experience, and a greater number of noninvasive ventilators were predictors of more frequent NIV use (all p < or = .001). Only 6% of respondents reported initiation of use and continued use most frequently in nonmonitored settings, which increased with the number of noninvasive ventilators (p = .02). Physician characteristics such as awareness of the literature were predictive of NIV use for exacerbations of chronic obstructive pulmonary disease, whereas perceived NIV efficacy was predictive of use for many indications, including congestive heart failure.

CONCLUSIONS

Self-reported practice variation for bilevel NIV exists among specialties but not hospitals and differs with respect to frequency, location of use, and use for specific indications. Some factors associated with variation in NIV use may be suitable targets for utilization improvement interventions.

Positive pressure ventilation in the management of acute and chronic cardiac failure: a systematic review and meta-analysis

Chronic heart failure (CHF) is a common condition and is associated with excess morbidity and mortality, in spite of the many advances in its treatment. Chronic stable heart failure is also associated with an increased incidence of sleep-related breathing disorders, such as central sleep apnoea (CSA) and Cheyne Stokes respiration (CSR). Continuous positive airways pressure (CPAP) has been shown to alleviate the symptoms of CHF, improve left ventricular function and oxygenation. To a certain extent, CPAP also abolishes sleep-related breathing disorders in patients with chronic heart failure. In patients with acute pulmonary oedema, the use of positive pressure ventilation improves cardiac haemodynamic indices, as well as symptoms and oxygenation, and is associated with a lower need for intubation. However, some studies have cast doubts about its safety and suggest a higher rate of myocardial infarction associated with its use. In our opinion, non-invasive positive pressure ventilation and CPAP offers an adjunctive mode of therapy in patients with acute pulmonary oedema and chronic heart failure, who may not be suitable for intubation and in those not responsive to conventional therapies. Non-invasive ventilation also helps to improve oxygenation in those patients with exhaustion and respiratory acidosis. Many trials are still ongoing and the results of these studies would throw more light on the present role of non-invasive ventilation in the management of CHF.

Recent advances in mechanical ventilation

Important advances have been made over the past decade towards understanding the optimal approach to ventilating patients with acute respiratory failure. Evidence now supports the use of noninvasive positive pressure ventilation in selected patients with hypercapnic respiratory failure and chronic obstructive pulmonary disease, cardiogenic pulmonary edema, and for facilitating the discontinuation of ventilatory support in patients with chronic pulmonary disease. The concept of a lung protective ventilatory strategy has revolutionized the management of the acute respiratory distress syndrome. The process of liberation from mechanical ventilation is becoming more standardized, with evidence supporting daily trials of spontaneous breathing in all suitable mechanically ventilated patients. This article critically reviews the most important recent advances in mechanical ventilation and suggests future directions for further research in the field.

Does continuous positive airway pressure by face mask improve patients with acute cardiogenic pulmonary edema due to left ventricular diastolic dysfunction?

OBJECTIVE

Continuous positive airway pressure (CPAP) by face mask is an effective method of treating severe cardiogenic pulmonary edema (CPE). However, to our knowledge, no study has provided a precise evaluation of the effects of CPAP on cardiac function in patients presenting with CPE and preserved left ventricular (LV) function.

DESIGN

Prospective observational clinical study.

SETTING

A 14-bed, medical ICU at a university hospital.

PATIENTS

Nine consecutive patients presenting with hypoxemic acute CPE.

INTERVENTIONS

All patients were selected for 30 min of CPAP with 10 cm H(2)O by mask with fraction of inspired oxygen adjusted for a cutaneous saturation > 90%. Doppler echocardiography was performed before CPAP application and during the last 10 min of breathing with CPAP. Two-tailed, paired t-tests were used to compare data recorded at baseline (oxygen alone) and after CPAP.

MEASUREMENTS AND RESULTS

Four patients presented CPE with preserved left ventricular (LV) function (a preserved LV ejection fraction [LVEF] > 45%, and/or aortic velocity time integral > 17 cm in the absence of aortic stenosis or hypertrophic cardiomyopathy). Oxygenation and ventilatory parameters were improved by CPAP in all patients. Hemodynamic monitoring and Doppler echocardiographic analysis demonstrated that in patients with preserved LV systolic function, mean arterial pressure and LV end-diastolic volume were decreased significantly by CPAP (p < 0.04). In patients with LV systolic dysfunction, CPAP improved LVEF (p < 0.05) and decreased LV end-diastolic volume (p = 0.001) significantly.

CONCLUSION

CPAP improves oxygenation and ventilatory parameters in all kinds of CPE. In patients with preserved LV contractility, the hemodynamic benefit of CPAP results from a decrease in LV end-diastolic volume (preload).

Noninvasive Positive-Pressure Ventilation To Treat Hypercapnic Coma Secondary to Respiratory Failure

INTRODUCTION

Hypercapnic coma secondary to acute respiratory failure (ARF) is considered to be a contraindication to the use of treatment with noninvasive positive-pressure ventilation (NPPV). However, intubation exposes these patients to the risk of complications such as nosocomial pneumonia, sepsis, and even death.

PATIENTS AND METHODS

We performed a prospective, open, noncontrolled study to assess the outcomes of NPPV therapy in patients with a Glasgow coma scale (GCS) score of </= 8 points due to ARF. The primary goal of the study was to determine the success of NPPV therapy (defined as a response to therapy allowing the patient to avoid endotracheal intubation, and to survive a stay in the ICU and at least 24 h on a medical ward) in patients with hypercapnic coma, compared to those who started NPPV therapy while awake. The secondary goal of the study was to identify the variables that can predict a failure of NPPV therapy in these patients.

RESULTS

A total of 76 coma patients (80%) responded to NPPV therapy, and 605 patients with GCS scores > 8 responded to therapy (70%; p = 0.04). A total of 25 coma patients died in the hospital (26.3%), and 287 noncoma patients died in the hospital (33.2%; p = 0.17). The variables related to the success of NPPV therapy were GCS score 1 h posttherapy (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.53 to 3.53) and higher levels of multiorgan dysfunction, as measured by the maximum sequential organ failure assessment index score reached during NPPV therapy (OR, 0.72; 95% CI, 0.55 to 0.92).

CONCLUSIONS

We concluded that selected patients with hypercapnic coma secondary to ARF can be treated as successfully with NPPV as awake patients with ARF.

Akute Herzinsuffizienz und kardiogener Schock

Irrespective of improved medical and interventional therapeutic options, mortality among patients with acute heart failure and cardiogenic shock has remained disappointingly high. Early diagnosis and rapid initiation of basic treatment measures to improve hemodynamics and metabolism are of vital importance until causal therapy, e. g. revascularization, is initiated. Due to the principal difficulty to set up larger clinical trials, in patients with cardiogenic shock empirical rather than firm evidence supports the various treatment and management strategies currently in use. Continuous hemodynamic monitoring to tailor fluid therapy, new drugs, and prognostic markers have been developed for the treatment and monitoring of cardiogenic shock, all of which await testing in larger-scale studies. Ongoing challenges remain the right ventricular pump failure or hemodynamically compromising arrhythmia which may be either cause or consequence of cardiogenic shock.

Randomised controlled comparison of continuous positive airways pressure, bilevel non-invasive ventilation, and standard treatment in emergency department patients with acute cardiogenic pulmonary oedema

BACKGROUND

Continuous positive airways pressure (CPAP) and bilevel non-invasive ventilation may have beneficial effects in the treatment of patients with acute cardiogenic pulmonary oedema. The efficacy of both treatments was assessed in the UK emergency department setting, in a randomised comparison with standard oxygen therapy.

METHODS

Sixty patients presenting with acidotic (pH<7.35) acute, cardiogenic pulmonary oedema, were randomly assigned conventional oxygen therapy, CPAP (10 cm H(2)O), or bilevel ventilation (IPAP 15 cm H(2)O, EPAP 5 cm H(2)O) provided by a standard ventilator through a face mask. The main end points were treatment success at two hours and in-hospital mortality. Analyses were by intention to treat.

RESULTS

Treatment success (defined as all of respiratory rate<23 bpm, oxygen saturation of>90%, and arterial blood pH>7.35 (that is, reversal of acidosis), at the end of the two hour study period) occurred in three (15%) patients in the control group, seven (35%) in the CPAP group, and nine (45%) in the bilevel group (p = 0.116). Fourteen (70%) of the control group patients survived to hospital discharge, compared with 20 (100%) in the CPAP group and 15 (75%) in the bilevel group (p = 0.029; Fisher's test).

CONCLUSIONS

In this study, patients presenting with acute cardiogenic pulmonary oedema and acidosis, were more likely to survive to hospital discharge if treated with CPAP, rather than with bilevel ventilation or with conventional oxygen therapy. There was no relation between in hospital survival and early physiological changes. Survival rates were similar to other studies despite a low rate of endotracheal intubation.

Factores de predicción del éxito de la ventilación no invasiva en el tratamiento del edema agudo de pulmón cardiogénico

BACKGROUND AND OBJECTIVE

Recent studies support the use of non invasive ventilation (NIV) in patients with acute cardiogenic pulmonary edema (ACPE). We aimed to evaluate the factors related to the success of the technique in patients admitted to an intensive care unit (ICU) with ACPE.

PATIENTS AND METHOD

An observational prospective study was performed in ICU.199 consecutive patients were enrolled with ACPE at admission who received treatment with NIV and standardized pharmacological treatment. The success of the NIV was achieved when endotracheal intubation was avoided and patients were alive without dyspnea within and 24 hours after discharge from the ICU. Clinical, physiological and gasometric parameters were analyzed at admission and one hour after starting NIV.

RESULTS

Patient's age was 74 years. 43% were male. The SAPS II was 45. 74.4% of the patients were successfully treated with NIV. 12.6% required endotracheal intubation. In a multivariate analysis, the success of the technique (values expressed as odds ratio [95% confidence interval]) was related to: SAPS II (0.95 [0.91-0.99]); the place of admission (6.78 [1.85-24.79]); value of PCO2 at admission (1.05 [1.01-1.09]); PO2/FiO2 index (1.03 [1.01-1.06]) and respiratory frequency (0.91 [0.84-0.99]) within the first hour; SOFA (acute failure organics score) (0.62 [0.49-0.78]); concomittant acute myocardial infarction (AMI) (0.05 [0.01-0.22]) and number of complications (0.17 [0.47-0.65]). The hospital mortality rate was 32.7%. The non intubation order (0.12 [0.04-0.32]) and the success of the technique (100.03 [28.71-348.47]) were related to the hospital mortality.

CONCLUSIONS

The success of NIV in the treatment of ACPE is related to a lower SAPS II, admission at the emergency department, elevated PCO2 at admission, improvement of the PO2/FiO2 index and the respiratory rate within the first hour. The non intubation order and the success of the technique were related to the hospital mortality.

Acute respiratory failure in the cancer patient: the role of non-invasive mechanical ventilation

The most common cause of ICU admission in patients affected by a hematologic or solid cancer is acute respiratory failure, often associated with a respiratory infection. The prognosis of these critically ill patients is disappointingly low especially if they require endotracheal intubation. In the last 10 years, non-invasive mechanical ventilation (NIV), delivered through a face or nose mask, has been increasingly used as an alternative to invasive ventilation. There is good evidence that, compared to the standard medical therapy alone or with invasive mechanical ventilation, NIV may improve survival and reduce the rate of infectious complications in patients affected by hematologic cancers. Patients with a solid tumor and "reversible" acute respiratory failure are also likely to benefit from NIV, while the use of NIV in palliative care of terminally ill patients still needs to be elucidated. The success of NIV is strictly dependent on its "early" use and on the experience of the staff involved.

Does noninvasive positive pressure ventilation improve outcome in acute hypoxemic respiratory failure? A systematic review

CONTEXT

The results of studies on noninvasive positive pressure ventilation (NPPV) for acute hypoxemic respiratory failure unrelated to cardiogenic pulmonary edema have been inconsistent.

OBJECTIVE

To assess the effect of NPPV on the rate of endotracheal intubation, intensive care unit and hospital length of stay, and mortality for patients with acute hypoxemic respiratory failure not due to cardiogenic pulmonary edema.

DATA SOURCE

We searched the databases of MEDLINE (1980 to October 2003) and EMBASE (1990 to October 2003). Additional data sources included the Cochrane Library, personal files, abstract proceedings, reference lists of selected articles, and expert contact.

STUDY SELECTION

We included studies if a) the design was a randomized controlled trial; b) patients had acute hypoxemic respiratory failure not due to cardiogenic pulmonary edema; c) the interventions compared noninvasive ventilation and standard therapy with standard therapy alone; and d) outcomes included need for endotracheal intubation, length of intensive care unit or hospital stay, or intensive care unit or hospital survival.

DATA EXTRACTION

In duplicate and independently, we abstracted data to evaluate methodological quality and results.

DATA SYNTHESIS

The addition of NPPV to standard care in the setting of acute hypoxemic respiratory failure reduced the rate of endotracheal intubation (absolute risk reduction 23%, 95% confidence interval 10-35%), ICU length of stay (absolute reduction 2 days, 95% confidence interval 1-3 days), and ICU mortality (absolute risk reduction 17%, 95% confidence interval 8-26%). However, trial results were significantly heterogeneous.

CONCLUSION

Randomized trials suggest that patients with acute hypoxemic respiratory failure are less likely to require endotracheal intubation when NPPV is added to standard therapy. However, the effect on mortality is less clear, and the heterogeneity found among studies suggests that effectiveness varies among different populations. As a result, the literature does not support the routine use of NPPV in all patients with acute hypoxemic respiratory failure.

Randomized, prospective trial of oxygen, continuous positive airway pressure, and bilevel positive airway pressure by face mask in acute cardiogenic pulmonary edema

OBJECTIVE

To compare the effects of oxygen, continuous positive airway pressure (CPAP), and bilevel positive airway pressure (bilevel-PAP) on the rate of endotracheal intubation in patients with acute cardiogenic pulmonary edema.

DESIGN

Randomized, controlled trial.

SETTING

Tertiary hospital emergency room.

PATIENTS

We randomly assigned 80 patients with severe cardiogenic acute pulmonary edema into three treatment groups. Patients were followed for 60 days after the randomization.

INTERVENTIONS

Oxygen applied by face mask, CPAP, and bilevel-PAP.

MEASUREMENTS AND MAIN RESULTS

The rate of endotracheal intubation as well as vital signs and blood gases was recorded during the first 24 hrs. Mortality was evaluated at 15 days, at 60 days, and at hospital discharge. Complications related to respiratory support were evaluated before hospital discharge. Treatment with CPAP or bilevel-PAP resulted in significant improvement in the PaO2/FiO2 ratio, subjective dyspnea score, and respiratory and heart rates compared with oxygen therapy. Endotracheal intubation was necessary in 11 of 26 patients (42%) in the oxygen group but only in two of 27 patients (7%) in each noninvasive ventilation group (p = .001). There was no increase in the incidence of acute myocardial infarction in the CPAP or bilevel-PAP groups. Mortality at 15 days was higher in the oxygen than in the CPAP or bilevel-PAP groups (p < .05). Mortality up to hospital discharge was not significantly different among groups (p = .061).

CONCLUSIONS

Compared with oxygen therapy, CPAP and bilevel-PAP resulted in similar vital signs and arterial blood gases and a lower rate of endotracheal intubation. No cardiac ischemic complications were associated with either of the noninvasive ventilation strategies.

Pediatric acute lung injury: prospective evaluation of risk factors associated with mortality

RATIONALE

The 1994 American European Consensus Committee definitions of acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) have not been applied systematically in the pediatric population.

OBJECTIVES

The purpose of this study was to evaluate prospectively the epidemiology and clinical risk factors associated with death and prolonged mechanical ventilation in all pediatric patients admitted to two large, pediatric intensive care units with ALI/ARDS using Consensus criteria.

METHODS

All pediatric patients meeting Consensus Committee definitions for ALI were prospectively identified and included in a relational database.

MEASUREMENTS AND MAIN RESULTS

There were 328 admissions for ALI/ARDS with a mortality of 22%. Multivariate logistic regression analyses revealed (1) the initial severity of oxygenation defect, as measured by the Pa(O2)/FI(O2) ratio; (2) the presence of nonpulmonary and non-central nervous system (CNS) organ dysfunction; and (3) the presence of CNS dysfunction were independently associated with mortality and prolonged mechanical ventilation. A substantial fraction of patients (28%) did not require mechanical ventilation at the onset of ALI; 46% of these patients eventually required intubation for worsening ALI.

CONCLUSIONS

Mortality in pediatric ALI/ARDS is high and several risk factors have major prognostic value. In contrast to ALI/ARDS in adults, the initial severity of arterial hypoxemia in children correlates well with mortality. A significant fraction of patients with pediatric ALI/ARDS can be identified before endotracheal intubation is required. These patients provide a valuable group in whom new therapies can be tested.