Myocardial infarction rate in acute pulmonary edema: noninvasive pressure support ventilation versus continuous positive airway pressure

Innovative Predictive Approach towards a Personalized Oxygen Dosing System

Despite the large impact chronic obstructive pulmonary disease (COPD) that has on the population, the implementation of new technologies for diagnosis and treatment remains limited. Current practices in ambulatory oxygen therapy used in COPD rely on fixed doses overlooking the diverse activities which patients engage in. To address this challenge, we propose a software architecture aimed at delivering patient-personalized edge-based artificial intelligence (AI)-assisted models that are built upon data collected from patients' previous experiences along with an evaluation function. The main objectives reside in proactively administering precise oxygen dosages in real time to the patient (the edge), leveraging individual patient data, previous experiences, and actual activity levels, thereby representing a substantial advancement over conventional oxygen dosing. Through a pilot test using vital sign data from a cohort of five patients, the limitations of a one-size-fits-all approach are demonstrated, thus highlighting the need for personalized treatment strategies. This study underscores the importance of adopting advanced technological approaches for ambulatory oxygen therapy.

Acute dyspnea in the emergency department: a clinical review

Acute dyspnea represents one of the most frequent symptoms leading to emergency room evaluation. Its significant prognostic value warrants a careful evaluation. The differential diagnosis of dyspnea is complex due to the lack of specificity and the loose association between its intensity and the severity of the underlying pathological condition. The initial assessment of dyspnea calls for prompt diagnostic evaluation and identification of optimal monitoring strategy and provides information useful to allocate the patient to the most appropriate setting of care. In recent years, accumulating evidence indicated that lung ultrasound, along with echocardiography, represents the first rapid and non-invasive line of assessment that accurately differentiates heart, lung or extra-pulmonary involvement in patients with dyspnea. Moreover, non-invasive respiratory support modalities such as high-flow nasal oxygen and continuous positive airway pressure have aroused major clinical interest, in light of their efficacy and practicality to treat patients with dyspnea requiring ventilatory support, without using invasive mechanical ventilation. This clinical review is focused on the pathophysiology of acute dyspnea, on its clinical presentation and evaluation, including ultrasound-based diagnostic workup, and on available non-invasive modalities of respiratory support that may be required in patients with acute dyspnea secondary or associated with respiratory failure.

Outcome of patients with acute heart failure secondary to acute myocardial infarction treated with noninvasive mechanical ventilation

INTRODUCTION AND OBJECTIVES

Noninvasive ventilation (NIV) has been shown to reduce the rate of endotracheal intubation and mortality in patients with acute heart failure (AHF). However, patients with AHF secondary to acute coronary syndrome/acute myocardial infarction (ACS-AMI) have been excluded from many clinical trials. The purpose of this study was to compare the effectiveness of NIV between patients with AHF triggered by ACS-AMI and by other etiologies.

METHODS

Prospective cohort study of all patients with AHF treated with NIV admitted to the intensive care unit for a period of 20 years. Patients were divided according to whether they had ACS-AMI as the cause of the AHF episode. NIV failure was defined as the need for endotracheal intubation or death.

RESULTS

A total of 1009 patients were analyzed, 403 (40%) showed ACS-AMI and 606 (60%) other etiologies. NIV failure occurred in 61 (15.1%) in the ACS-AMI group and in 64 (10.6%) in the other group (P=.031), without differences in in-hospital mortality (16.6% and 14.9%, respectively; P=.478).

CONCLUSIONS

The presence of ACS-AMI as the triggering cause of AHF did not influence patients with acute respiratory failure requiring noninvasive respiratory support.

Bilevel positive airway pressure ventilation for non-COPD acute hypercapnic respiratory failure patients: A systematic review and meta-analysis

The effectiveness of bi-level positive airway pressure (BiPAP) in patients with acute hypercapnic respiratory failure (AHRF) due to etiologies other than chronic obstructive pulmonary disease (COPD) is unclear. To systematically review the evidence regarding the effectiveness of BiPAP in non-COPD patients with AHRF. The Cochrane Library, MEDLINE, EMBASE, and CINAHL Plus were searched according to prespecified criteria (PROSPERO-CRD42018089875). Randomized controlled trials (RCTs) assessing the effectiveness of BiPAP versus continuous positive airway pressure (CPAP), invasive mechanical ventilation, or O₂ therapy in adults with non-COPD AHRF were included. The primary outcomes of interest were the rate of endotracheal intubation (ETI) and mortality. Risk-of-bias assessment was performed, and data were synthesized and meta-analyzed where appropriate. Two thousand four hundred and eighty-five records were identified after removing duplicates. Eighty-eight articles were identified for full-text assessment, of which 82 articles were excluded. Six studies, of generally low or uncertain risk-of-bias, were included involving 320 participants with acute cardiogenic pulmonary edema (ACPO) and solid tumors. No significant differences were seen between BiPAP ventilation and CPAP with regard to the rate of progression to ETI (risk ratio [RR] = 1.49, 95% confidence interval [CI], 0.63-3.62, P = 0.37) and in-hospital mortality rate (RR = 0.71, 95% CI, 0.25-1.99, P = 0.51) in patients with AHRF due to ACPO. The efficacy of BiPAP appears similar to CPAP in reducing the rates of ETI and mortality in patients with AHRF due to ACPO. Further research on other non-COPD conditions which commonly cause AHRF such as obesity hypoventilation syndrome is needed.

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

BACKGROUND

Non-invasive positive pressure ventilation (NPPV) has been used to treat respiratory distress due to acute cardiogenic pulmonary oedema (ACPE). We performed a systematic review and meta-analysis update on NPPV for adults presenting with ACPE.

OBJECTIVES

To evaluate the safety and effectiveness of NPPV compared to standard medical care (SMC) for adults with ACPE. The primary outcome was hospital mortality. Important secondary outcomes were endotracheal intubation, treatment intolerance, hospital and intensive care unit length of stay, rates of acute myocardial infarction, and adverse event rates.

SEARCH METHODS

We searched CENTRAL (CRS Web, 20 September 2018), MEDLINE (Ovid, 1946 to 19 September 2018), Embase (Ovid, 1974 to 19 September 2018), CINAHL Plus (EBSCO, 1937 to 19 September 2018), LILACS, WHO ICTRP, and clinicaltrials.gov. We also reviewed reference lists of included studies. We applied no language restrictions.

SELECTION CRITERIA

We included blinded or unblinded randomised controlled trials in adults with ACPE. Participants had to be randomised to NPPV (continuous positive airway pressure (CPAP) or bilevel NPPV) plus standard medical care (SMC) compared with SMC alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened and selected articles for inclusion. We extracted data with a standardised data collection form. We evaluated the risks of bias of each study using the Cochrane 'Risk of bias' tool. We assessed evidence quality for each outcome using the GRADE recommendations.

MAIN RESULTS

We included 24 studies (2664 participants) of adult participants (older than 18 years of age) with respiratory distress due to ACPE, not requiring immediate mechanical ventilation. People with ACPE presented either to an Emergency Department or were inpatients. ACPE treatment was provided in an intensive care or Emergency Department setting. There was a median follow-up of 13 days for hospital mortality, one day for endotracheal intubation, and three days for acute myocardial infarction. Compared with SMC, NPPV may reduce hospital mortality (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.51 to 0.82; participants = 2484; studies = 21; I² = 6%; low quality of evidence) with a number needed to treat for an additional beneficial outcome (NNTB) of 17 (NNTB 12 to 32). NPPV probably reduces endotracheal intubation rates (RR 0.49, 95% CI 0.38 to 0.62; participants = 2449; studies = 20; I² = 0%; moderate quality of evidence) with a NNTB of 13 (NNTB 11 to 18). There is probably little or no difference in acute myocardial infarction (AMI) incidence with NPPV compared to SMC for ACPE (RR 1.03, 95% CI 0.91 to 1.16; participants = 1313; studies = 5; I² = 0%; moderate quality of evidence). We are uncertain as to whether NPPV increases hospital length of stay (mean difference (MD) -0.31 days, 95% CI -1.23 to 0.61; participants = 1714; studies = 11; I² = 55%; very low quality of evidence). Adverse events were generally similar between NPPV and SMC groups, but evidence was of low quality.

AUTHORS' CONCLUSIONS

Our review provides support for continued clinical application of NPPV for ACPE, to improve outcomes such as hospital mortality and intubation rates. NPPV is a safe intervention with similar adverse event rates to SMC alone. Additional research is needed to determine if specific subgroups of people with ACPE have greater benefit of NPPV compared to SMC. Future research should explore the benefit of NPPV for ACPE patients with hypercapnia.

Indications and practical approach to non-invasive ventilation in acute heart failure

In acute heart failure (AHF) syndromes significant respiratory failure (RF) is essentially seen in patients with acute cardiogenic pulmonary oedema (ACPE) or cardiogenic shock (CS). Non-invasive ventilation (NIV), the application of positive intrathoracic pressure through an interface, has shown to be useful in the treatment of moderate to severe RF in several scenarios. There are two main modalities of NIV: continuous positive airway pressure (CPAP) and pressure support ventilation (NIPSV) with positive end expiratory pressure. Appropriate equipment and experience is needed for NIPSV, whereas CPAP may be administered without a ventilator, not requiring special training. Both modalities have shown to be effective in ACPE, by a reduction of respiratory distress and the endotracheal intubation rate compared to conventional oxygen therapy, but the impact on mortality is less conclusive. Non-invasive ventilation is also indicated in patients with AHF associated to pulmonary disease and may be considered, after haemodynamic stabilization, in some patients with CS. There are no differences in the outcomes in the studies comparing both techniques, but CPAP is a simpler technique that may be preferred in low-equipped areas like the pre-hospital setting, while NIPSV may be preferable in patients with significant hypercapnia. The new modality 'high-flow nasal cannula' seems promising in cases of AHF with less severe RF. The correct selection of patients and interfaces, early application of the technique, the achievement of a good synchrony between patients and the ventilator avoiding excessive leakage, close monitoring, proactive management, and in some cases mild sedation, may warrant the success of the technique.

Acute Effects of Positive Airway Pressure on Functional Mitral Regurgitation in Patients with Systolic Heart Failure

Background: Acute effects of positive airway pressure (PAP) [including continuous PAP (CPAP) and adaptive servo-ventilation, an advanced form of bi-level PAP] on functional mitral regurgitation (fMR) in patients with heart failure (HF) with left ventricular (LV) systolic dysfunction remain unclear. Thus, whether PAP therapy reduces fMR in such patients with HF was investigated. Methods and Results: Twenty patients with HF and LV systolic dysfunction defined as LV ejection fraction (LVEF) <50% (14 men; mean LVEF, 35.0 ± 11.5%) with fMR underwent echocardiography during 10-min CPAP (4 and 8 cm H₂O) and adaptive servo-ventilation. For fMR assessment, MR jet area fraction, defined as the ratio of MR jet on color Doppler to the left atrial area, was measured. The forward stroke volume (SV) index (fSVI) was calculated from the time-velocity integral, cross-sectional area of the aortic annulus, and body surface area. fMR significantly reduced on CPAP at 8 cm H₂O (0.30 ± 0.12) and adaptive servo-ventilation (0.29 ± 0.12), compared with the baseline phase (0.37 ± 0.12) and CPAP at 4 cm H₂O (0.34 ± 0.12) (P < 0.001). The fSVI did not change in any of the PAP sessions (P = 0.888). However, significant differences in fSVI responses to PAP were found between sexes (P for interaction, 0.006), with a significant reduction in fSVI in women (P = 0.041) and between patients with baseline fSVI ≥ and < the median value (27.8 ml/m², P for interaction, 0.018), with a significant fSVI reduction in patients with high baseline fSVI (P = 0.028). In addition, significant differences were found in fSVI responses to PAP between patients with LV end-systolic volume (LVESV) index ≥ and < the median value (62.0 ml/m², P for interaction, 0.034), with a significant fSVI increase in patients with a high LVESV index (P = 0.023). Conclusion: In patients with HF, LV systolic dysfunction, and fMR, PAP can alleviate fMR without any overall changes in forward SV. However, MR alleviation due to PAP might be associated with a decrease in forward SV in women with high baseline SV, whereas MR alleviation due to PAP might be accompanied by increased forward SV in patients with a dilated LV.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Risk factors for noninvasive ventilation failure in patients with acute cardiogenic pulmonary edema: A prospective, observational cohort study

PURPOSE

We identified risk factors for noninvasive ventilation (NIV) failure in patients with acute cardiogenic pulmonary edema (ACPE).

MATERIALS AND METHODS

We conducted an observational cohort study over a 3-year period in a 28-bed emergency intensive care unit (EICU) and prospectively included all consecutive patients in whom NIV was attempted as initial ventilatory support for ACPE. The primary outcome variables were NIV failure rate and risk factors for NIV failure.

RESULTS

Among the 118 patients in the study, NIV failed for 44 (37.3%) patients. Risk factors for NIV failure were Killip class IV (odds ratio [OR], 28.56; 95% confidence interval [CI], 2.17-375.73; p=0.011), left ventricular ejection fraction (LVEF) <30% (OR, 9.54; 95% CI, 1.01-90.55; p=0.050) and B-type natriuretic peptide (BNP) ≥3350pg/mL (OR, 39.63; 95% CI, 3.92-400.79; p=0.002) at baseline, and fluid balance ≥400mL within 24h after ACPE (OR, 13.19; 95% CI, 1.18-147.70; p=0.036).

CONCLUSIONS

NIV failure occurred in 37.3% of ACPE patients in a real-world EICU. When patients had Killip class IV, a lower LVEF, a higher BNP, and a more positive fluid balance within 24h after ACPE, the risk of failure was higher. TRIAL REGISTRATION CLINICALTRIALS.

GOV IDENTIFIER

NCT02653365.

Acidemia in severe acute cardiogenic pulmonary edema treated with noninvasive pressure support ventilation: a single-center experience

In clinical practice, acidotic patients with acute cardiogenic pulmonary edema (ACPE) are commonly considered more severe in comparison with nonacidotic patients, and data on the outcome of these patients treated with noninvasive pressure support ventilation (NIV) are lacking.The present investigation was aimed at assessing whether acidosis on admission (pH < 7.35) was associated with adverse outcome in 65 consecutive patients with ACPE treated with NIV and admitted to our Intensive Cardiac Care Unit (ICCU).In our population, 28 patients were acidotic (28 of 65, 43.1%), whereas 41 patients were not (37 of 65, 56.9%). According to the Repeated Measures General Linear Model, pCO2 values significantly changed throughout the 2-h NIV treatment (P = 0.019) in both groups (P = 0001). In acidotic patients, pCO2 significantly decreased (51.9 ± 15.3 → 47.0 ± 12.8 → 44.8 ± 12.7), whereas they increased in the nonacidotic subgroup (36.8 ± 6.5 → 36.9 ± 7.2 → 37.6 ± 6.4). No difference was observed in intubation rate between acidotic (eight patients, 28.6%) and nonacidotic patients (12 patients, 32.4%) (P = 0.738). In-ICCU mortality rate did not differ between (13 patients, 35.1%) and nonacidotic patients (nine patients, 32.1%) (P = 0.801).Our data strongly suggest that in patients with severe ACPE treated with NIV, the presence of acidosis is not associated with adverse outcomes (early mortality and intubation rates) in these patients.

Noninvasive ventilation in acute respiratory failure

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

Acute effects of continuous positive air way pressure on pulse pressure in chronic heart failure

BACKGROUND

Patients with heart failure (HF) have left ventricular dysfunction and reduced mean arterial pressure (MAP). Increased adrenergic drive causes vasoconstriction and vessel resistance maintaining MAP, while increasing peripheral vascular resistance and conduit vessel stiffness. Increased pulse pressure (PP) reflects a complex interaction of the heart with the arterial and venous systems. Increased PP is an important risk marker in patients with chronic HF (CHF). Non-invasive ventilation (NIV) has been used for acute decompensated HF, to improve congestion and ventilation through both respiratory and hemodynamic effects. However, none of these studies have reported the effect of NIV on PP.

OBJECTIVE

The objective of this study was to determine the acute effects of NIV with CPAP on PP in outpatients with CHF.

METHODS

Following a double-blind, randomized, cross-over, and placebo-controlled protocol, twenty three patients with CHF (17 males; 60±11 years; BMI 29±5 kg/cm2, NYHA class II, III) underwent CPAP via nasal mask for 30 min in a recumbent position. Mask pressure was 6 cmH2O, whereas placebo was fixed at 0-1 cmH2O. PP and other non invasive hemodynamics variables were assessed before, during and after placebo and CPAP mode.

RESULTS

CPAP decreased resting heart rate (Pre: 72±9; vs. Post 5 min: 67±10 bpm; p<0.01) and MAP (CPAP: 87±11; vs. control 96±11 mmHg; p<0.05 post 5 min). CPAP decreased PP (CPAP: 47±20 pre to 38±19 mmHg post; vs. control: 42±12 mmHg, pre to 41±18 post p<0.05 post 5 min).

CONCLUSION

NIV with CPAP decreased pulse pressure in patients with stable CHF. Future clinical trials should investigate whether this effect is associated with improved clinical outcome.

The role of non-invasive positive pressure ventilation in post-extubation respiratory failure: An evaluation using meta-analytic techniques

Background:

The use of non-invasive positive pressure ventilation (NIPPV) in post-extubation respiratory failure is not well-established. Meta-analytic techniques were used to assess the effects of prophylactic application of NIPPV (prior to the development of respiratory failure) and therapeutic application of NIPPV (subsequent to the development of respiratory failure).

Materials and Methods:

Randomized controlled trials (RCTs) from 1966 to May 2010 were identified using electronic databases. RCTs, which reported the use of NIPPV in post-extubation respiratory failure with defined assessable endpoints: reintubation, mortality and length of stay, were included.

Results:

Reintubation was the primary outcome, mortality and lengths of stay were the secondary outcomes. Risk ratios (RR) were calculated for discrete outcomes and weighted mean differences (WMD) for continuous measures. There were 13 trials with 1420 patients; 9 prophylactic with 861 patients and 4 therapeutic with 559 patients. In the prophylactic group, NIPPV was associated with lower rates of reintubation: RR 0.53 (95% confidence interval [CI], 0.28-0.98), P = 0.04. In the therapeutic group, NIPPV showed a null effect on reintubation: RR 0.79 (95% CI, 0.50-1.25), P = 0.31. The analysis on the secondary outcomes suggested significant reduction of hospital mortality with prophylactic application of NIPPV: RR 0.62 (95% CI 0.4-0.97), P = 0.03, with no effect on the other outcomes. Therapeutic application of NIPPV reduced intensive care unit length of stay: WMD −1.17 (95% CI −2.82 to −0.33), P = 0.006, but no effect on the other secondary outcomes.

Conclusions:

The results of this review suggested prophylactic NIPPV was beneficial with respect to reintubation and the therapeutic use of NIPPV showed a null effect.

Randomized trial of bilevel versus continuous positive airway pressure for acute pulmonary edema

BACKGROUND

Studies have shown different clinical outcomes of noninvasive positive pressure ventilation (NPPV) from those of continuous positive airway pressure (CPAP).

OBJECTIVE

We evaluated whether bilevel positive airway pressure (BPAP) more rapidly improves dyspnea, ventilation, and acidemia without increasing the myocardial infarction (MI) rate compared to continuous positive pressure ventilation (CPAP) in patients with acute cardiogenic pulmonary edema (APE).

METHODS

Patients with APE were randomized to either BPAP or CPAP. Vital signs and dyspnea scores were recorded at baseline, 30 min, 1 h, and 3 h. Blood gases were obtained at baseline, 30 min, and 1 h. Patients were monitored for MI, endotracheal intubation (ETI), lengths of stay (LOS), and hospital mortality.

RESULTS

Fourteen patients received CPAP and 13 received BPAP. The two groups were similar at baseline (ejection fraction, dyspnea, vital signs, acidemia/oxygenation) and received similar medical treatment. At 30 min, PaO2:FIO2 was improved in the BPAP group compared to baseline (283 vs. 132, p < 0.05) and the CPAP group (283 vs. 189, p < 0.05). Thirty-minute dyspnea scores were lower in the BPAP group compared to the CPAP group (p = 0.05). Fewer BPAP patients required intensive care unit (ICU) admission (38% vs. 92%, p < 0.05). There were no differences between groups in MI or ETI rate, LOS, or mortality.

CONCLUSIONS

Compared to CPAP to treat APE, BPAP more rapidly improves oxygenation and dyspnea scores, and reduces the need for ICU admission. Further, BPAP does not increase MI rate compared to CPAP.

A comparison of bilevel and continuous positive airway pressure noninvasive ventilation in acute cardiogenic pulmonary edema

BACKGROUND

Whether bilevel positive airway pressure (BiPAP) is advantageous compared with continuous positive airway pressure (CPAP) in acute cardiogenic pulmonary edema (ACPO) remains uncertain. The aim of the meta-analysis was to assess potential beneficial and adverse effects of CPAP compared with BiPAP in patients with ACPO.

METHODS

Randomized controlled trials comparing the treatment effects of BiPAP with CPAP were identified from electronic databases and reference lists from January 1966 to December 2012. Two reviewers independently assessed study quality. In trials that fulfilled inclusion criteria, we critically evaluate the evidence for the use of noninvasive ventilation on rates of hospital mortality, endotracheal intubation, myocardial infarction, and the length of hospital stay. Data were combined using Review Manager 4.3 (The Cochrane Collaboration, Oxford, UK). Both pooled effects and 95% confidence intervals (CIs) were calculated.

RESULTS

Twelve randomized controlled trials with a total of 1433 patients with ACPO were included. The hospital mortality (relative risk [RR], 0.86; 95% CI, 0.65-1.14; P = .46; I(2) = 0%) and need for requiring invasive ventilation (RR, 0.89; 95% CI, 0.57-1.38; P = .64; I(2) = 0%) were not significantly different between patients treated with CPAP and those treated with BiPAP. The occurrence of new cases of myocardial infarction (RR, 0.95; 95% CI, 0.77-1.17; P = .53, I(2) = 0%) and length of hospital stay (RR, 1.01; 95% CI, -0.40 to 2.41; P = .98; I(2) = 0%) were also not significantly different between the 2 groups.

CONCLUSIONS

There are no significant differences in clinical outcomes when comparing CPAP vs BiPAP. Based on the limited data available, our results suggest that there are no significant differences in clinical outcomes when comparing CPAP with BiPAP.

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.

Complications of non-invasive ventilation techniques: a comprehensive qualitative review of randomized trials

Non-invasive ventilation (NIV) has become a common treatment for acute and chronic respiratory failure. In comparison with conventional invasive mechanical ventilation, NIV has the advantages of reducing patient discomfort, procedural complications, and mortality. However, NIV is associated with frequent uncomfortable or even life-threatening adverse effects, and patients should be thoroughly screened beforehand to reduce potential severe complications. We performed a detailed review of the relevant medical literature for NIV complications. All major NIV complications are potentially life-threatening and can occur in any patient, but are strongly correlated with the degree of pulmonary and cardiovascular involvement. Minor complications can be related to specific structural features of NIV interfaces or to variable airflow patterns. This extensive review of the literature shows that careful selection of patients and interfaces, proper setting of ventilator modalities, and close monitoring of patients from the start can greatly reduce NIV complications.

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.

The Albumin in Subarachnoid Hemorrhage (ALISAH) multicenter pilot clinical trial: safety and neurologic outcomes

BACKGROUND AND PURPOSE

Human albumin has been shown to exert neuroprotective effects in animal models of cerebral ischemia and humans with various intracranial pathologies. We investigated the safety and tolerability of 25% human albumin in patients with subarachnoid hemorrhage.

METHODS

The Albumin in Subarachnoid Hemorrhage (ALISAH) Pilot Clinical Trial was an open-label, dose-escalation study. We intended to study 4 different dosages of albumin of increasing magnitude (0.625 g/kg: Tier 1; 1.25 g/kg: Tier 2; 1.875 g/kg: Tier 3; and 2.5 g/kg: Tier 4). Each dosage was to be given to 20 adult patients. Treatment was administered daily for 7 days. We investigated the maximum tolerated dose of albumin based on the rate of severe-to-life-threatening heart failure and anaphylactic reaction and functional outcome at 3 months.

RESULTS

We treated 47 adult subjects: 20 in Tier 1; 20 in Tier 2; and 7 in Tier 3. We found that doses ranging up to 1.25 g/kg/day×7 days were tolerated by patients without major dose-limiting complications. We also found that outcomes trended toward better responses in those subjects enrolled in Tier 2 compared with Tier 1 (OR, 3.0513; CI, 0.6586-14.1367) and with the International Intraoperative Hypothermia for Aneurysm Surgery Trial cohort (OR, 3.1462; CI, 0.9158-10.8089).

CONCLUSIONS

Albumin in doses ranging up to 1.25 g/kg/day×7 days was tolerated by patients with subarachnoid hemorrhage without major complications and may be neuroprotective. Based on these results, planning of the ALISAH II, a Phase III, randomized, placebo-controlled trial to test the efficacy of albumin, is underway.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov. Unique identifier: NCT00283400.

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.

Treatment of subarachnoid hemorrhage with human albumin: ALISAH study. Rationale and design

The primary objective of this prospective dose-finding pilot study is to demonstrate the tolerability and safety of four dosages of 25% human albumin in patients with subarachnoid hemorrhage (SAH). For each dosage group, the study will enroll 20 patients who meet the eligibility criteria. The enrolled patients will undergo follow-up for 90 days post-treatment. The primary tolerability hypothesis is that intravenous 25% human albumin can be given without precipitating treatment related serious adverse events beyond expectations. The study will determine the maximum tolerated dosage of 25% human albumin therapy based on the rate of treatment related serious adverse events during treatment: severe or life-threatening heart failure. The secondary objectives are to obtain preliminary estimates of the albumin treatment effect using the incidence of neurological deterioration within 15 days after symptom onset. In addition, the incidence of rebleeding, hydrocephalus, seizures, delayed cerebral ischemia and the incidence of vasospasm (both symptomatic and by transcranial Doppler ultrasound criteria) within 15 days after symptom onset will be evaluated. Furthermore, the serum osmolality and serum albumin concentrations, serum magnesium concentration, blood pressure and heart rate within 15 days of symptom onset will also be observed. The Glasgow Outcome Scale, Barthel Index, modified Rankin Scale, NIH Stroke Scale, and Stroke Impact Scale will be performed 3 months after the onset of symptoms to assess residual neurological deficits.

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.

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.

Patient outcomes after noninvasive mechanical ventilation at a high dependency unit of an emergency department

OBJECTIVE

To describe the outcome of patients after noninvasive ventilation in a high dependency unit (HDU) of an emergency department (ED). Secondary aims were to define the role of intensive care consultation and to identify variables associated with mortality.

METHODS

Observational, prospective 6-month study.

RESULTS

Two hundred and nine cases were analysed. Thirty-four patients were initially rejected by the intensive care unit (ICU). Physicians in the ED did not request ICU consultation in the remaining 175 (83%) because of 'belief of improvable medical condition in the ED in patients without therapeutic limits' in 93 (group 1) and to 'preset therapeutic limits' or 'comfort measures only' in 82 (groups 2 and 3). Ten out of these 175 were subsequently admitted to the ICU. The global in-hospital mortality rate was 22% (3.3% in the high dependency unit), but only 10% in group 1. Place of referral for ventilation (P<0.001), absence of subsequent ventilation on the general ward (P<0.001), group of assignation (P=0.004), intensive care initial rejection (P=0.022), no previous home ventilation (P=0.028), older age (P=0.03) and longer duration on ventilation (P=0.047) were significantly associated with mortality. In the multivariate regression model, ventilating patients from general wards (odds ratio=7.1; 2.3-25, 95% confidence interval) and ventilation under preset limits (odds ratio=3.57; 1.42-8.98, 95% confidence interval) remained significantly associated with mortality.

CONCLUSION

Noninvasive ventilation is a relatively safe and effective treatment in the ED when performed in carefully controlled settings. ICU consultation may be securely deferred in this setting.

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.

Noninvasive ventilation in acute cardiogenic pulmonary edema

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Noninvasive ventilation in acute cardiogenic pulmonary edema

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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.

Prehospital noninvasive pressure support ventilation for acute cardiogenic pulmonary edema

Severe acute cardiogenic pulmonary edema (ACPE) can successfully be treated with noninvasive pressure support ventilation (NIPSV) in a clinical setting. Whether prehospital NIPSV starting early at patients' home and being continued until hospital arrival is feasible and improves ACPE emergency care is examined in this study. End points of the study were oxygen saturation at hospital admission and clinical outcome. Twenty-three patients suffering from severe cardiac pulmonary edema with severe dyspnea, an oxygen saturation of less than 90% and basal rales were included in this controlled prospective randomized trial. All patients received standard medical treatment and 10 patients were additionally treated with NIPSV (pressure support level, 12 cmH2O; positive endexpiratory pressure, 5 cmH2O; FiO2, 0.6) whereas the other patients received oxygen (8 l/min) via Venturi face mask. Improvement in oxygen saturation was significantly faster in the NIPSV group and oxygen saturation was higher at the time of the hospital admission (NIPSV=97.3+/-0.8%; standard=89.5+/-2.7%, P=0.002). A trend toward higher troponin T levels was seen in the standard treatment group. The need for intensive care treatment did not differ, and one patient of each treatment group died in hospital. No complications were noted during the treatment with NIPSV. Prehospital NIPSV is feasible and able to improve emergency management of ACPE.

Noninvasive positive airway pressure and risk of myocardial infarction in acute cardiogenic pulmonary edema: continuous positive airway pressure vs noninvasive positive pressure ventilation

BACKGROUND

The addition of both noninvasive continuous positive airway pressure (n-CPAP) or noninvasive intermittent positive pressure ventilation (n-IPPV) to medical treatment has been shown to improve the outcome of patients with acute cardiogenic pulmonary edema (ACPE). Previous studies indicated a potential risk of new-onset acute myocardial infarction (AMI) associated with the use of n-IPPV. Although further studies did not confirm this observation, a few recent metaanalyses could not eliminate all the doubts at this regards because of the paucity of data available and the presence of confounding factors. This study aims to assess whether the application of n-IPPV, as opposed to n-CPAP, increases the rate of AMI in ACPE patients.

METHODS

Fifty-two patients with severe hypoxemia consequent to ACPE were randomized to receive n-CPAP (n = 27) or n-IPPV (n = 25) in addition to medical therapy. Patients with signs of acute coronary syndrome on hospital admission were excluded from the study. Cardiac markers, ECG, and clinical/physiologic parameters were assessed at study entry, after 30 and 60 min, and every 6 h for the first 2 days.

RESULTS

No significant difference was observed in the rate of AMI (26.9% and 16% with n-CPAP and n-IPPV, respectively, p = 0.244). Rate of intubation (p = 0.481), death (p = 0.662), and hospital stay (p = 0.529) were not different between the two groups. Both techniques were effective in improving gas exchange and vital signs in patients with ACPE.

CONCLUSIONS

The AMI rate was not different with n-CPAP and n-IPPV, which resulted to be equally effective in the treatment of ACPE.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT00453947.

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.

Non-invasive ventilation

Non-invasive ventilation (NIV) refers to the delivery of mechanical ventilation to the lungs using techniques that do not require an endotracheal airway. Essentially, there are two modalities: continuous positive airway pressure (CPAP) and pressure support ventilation (NIPSV). In acute pulmonary edema (APE) both modalities have shown a faster improvement in gas exchange and physiologic parameters with respect to conventional oxygen therapy. CPAP is a simple technique that may reduce preload and afterload, increasing cardiac output in some patients. It has been successfully used in APE in the last 30 years, demonstrating a reduction in the intubation rate and mortality. The most common level of pressure is 10 cmH(2)O. NIPSV is a more complex mode that requires a ventilator and experience. It is usually applied with an expiratory pressure (EPAP or PEEP), resulting in a bilevel pressure modality (BIPAP). This technique has been introduced most recently in APE and has also shown a reduction in the intubation rate and a tendency to reduce mortality. The inspiratory help may be particularly useful in those patients with fatigue and hypercapnia. However, this hypothetical advantage over CPAP has not been demonstrated in comparative trials. The ventilator is usually set at 5 cmH(2)O of EPAP and inspiratory pressure between 12 and 25 cmH(2)O, although initially, the level of pressure support is lower. It is essential to achieve a good adaptation and synchronicity between the patient and the ventilator, reducing leakage to a minimum. The use of facial masks, high FiO(2), and sedation with opiates are complementary maneuvers that may be recommended in this context in the majority of patients.