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

Development and internal validation of a clinical prediction model to predict independence in daily living at discharge for patients with heart failure: analysis using a Japanese national inpatient database real-world dataset

PURPOSE

To develop a clinical prediction model (CPM) to predict independence in activities of daily living (ADLs) in patients with heart failure.

SUBJECTS AND METHODS

We collected the data of the individuals who were admitted and rehabilitated for heart failure from January 2017 to June 2022 from Japan's Diagnosis Procedure Combination database. We assessed the subjects' ADLs at discharge using the Barthel Index and classified them into independence, partial-independence, and total-dependence groups based on their ADLs at discharge. Two CPMs (an independence model and a partial-independence model) were developed by a binomial logistic regression analysis. The predictors included subject characteristics, treatment, and post-hospitalization disease onset. The CPMs' accuracy was validated by the area under the curve (AUC). Internal validation was performed using the bootstrap method. The final CPM is presented in a nomogram.

RESULTS

We included 96,753 patients whose ADLs could be traced at discharge. The independence model had a 0.73 mean AUC and a 1.0 slope at bootstrapping. We thus developed a simplified model using nomograms, which also showed adequate predictive accuracy in the independence model. The partial-independence model had a 0.65 AUC and inadequate predictive accuracy.

CONCLUSIONS

The independence model of ADLs in patients with heart failure is a useful CPM.

Cardiogenic Pulmonary Edema in Emergency Medicine

Cardiogenic pulmonary edema (CPE) is characterized by the development of acute respiratory failure associated with the accumulation of fluid in the lung's alveolar spaces due to an elevated cardiac filling pressure. All cardiac diseases, characterized by an increasing pressure in the left side of the heart, can cause CPE. High capillary pressure for an extended period can also cause barrier disruption, which implies increased permeability and fluid transfer into the alveoli, leading to edema and atelectasis. The breakdown of the alveolar-epithelial barrier is a consequence of multiple factors that include dysregulated inflammation, intense leukocyte infiltration, activation of procoagulant processes, cell death, and mechanical stretch. Reactive oxygen and nitrogen species (RONS) can modify or damage ion channels, such as epithelial sodium channels, which alters fluid balance. Some studies claim that these patients may have higher levels of surfactant protein B in the bloodstream. The correct approach to patients with CPE should include a detailed medical history and a physical examination to evaluate signs and symptoms of CPE as well as potential causes. Second-level diagnostic tests, such as pulmonary ultrasound, natriuretic peptide level, chest radiograph, and echocardiogram, should occur in the meantime. The identification of the specific CPE phenotype is essential to set the most appropriate therapy for these patients. Non-invasive ventilation (NIV) should be considered early in the treatment of this disease. Diuretics and vasodilators are used for pulmonary congestion. Hypoperfusion requires treatment with inotropes and occasionally vasopressors. Patients with persistent symptoms and diuretic resistance might benefit from additional approaches (i.e., beta-agonists and pentoxifylline). This paper reviews the pathophysiology, clinical presentation, and management of CPE.

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.

High-flow nasal cannula improves hypoxemia in dogs failing conventional oxygen therapy

OBJECTIVE

A prospective clinical trial was performed to evaluate the efficacy and tolerance of high-flow nasal cannula (HFNC) in dogs with hypoxemia.

ANIMALS

20 client-owned dogs failing conventional oxygen therapy (COT).

PROCEDURES

Patients admitted to the ICU for treatment of hypoxemic respiratory failure were enrolled in the study. PaO2, SPO2, respiratory rate (RR), and acute patient physiologic and laboratory evaluation scores were obtained at the time of COT failure and after initiation of HFNC. Complications and patient tolerance while receiving HFNC were also recorded.

RESULTS

Compared to COT, the median PaO2 and SO2 were significantly higher when dogs were receiving HFNC (60.8 vs 135.6 mm Hg and 90.7% vs 99.25%, respectively). Dogs receiving HFNC had a significant reduction in median RR as compared to dogs undergoing COT (52 vs 36 breaths per minute). After the initiation of HFNC, all dogs showed clinical improvement as measured by PaO2, SO2, and RR. Of 20 dogs, 6 ultimately failed HFNC and mechanical ventilation was recommended. Nine dogs undergoing HFNC survived to discharge, and acute patient physiologic and laboratory evaluation scores had a significant positive severity correlation with death. Complications included pneumothorax in 1 dog.

CLINICAL RELEVANCE

COT has limited flow rates due to airway irritation caused by room temperature, nonhumidified oxygen. HFNC uses vapor humidification and heated oxygen, allowing for higher flow rates. In people, HFNC is used as escalation of oxygen therapy when COT fails. Dogs treated with HFNC had significant improvements in PaO2, SO2, and RR as compared to COT. HFNC is well tolerated and effective in treating hypoxemia in dogs.

Clinical Benefit of Extubation in Patients on Venoarterial Extracorporeal Membrane Oxygenation

OBJECTIVES

Although patients on venoarterial extracorporeal membrane oxygenation for refractory cardiogenic shock are usually supported with mechanical ventilation, it is not clear whether sedation cessation and extubation might improve outcomes.

DESIGN

Retrospective cohort study with propensity score overlap weighting analysis.

SETTING

Three ICUs in a 1,500-bed tertiary university hospital.

PATIENTS

From an overall cohort of 641 patients with venoarterial-extracorporeal membrane oxygenation support, the primary analysis was performed in 344 patients who had been successfully decannulated in order to reduce immortal time bias.

MEASUREMENTS AND MAIN RESULTS

Seventy-five patients (22%) were extubated during extracorporeal membrane oxygenation support and were subsequently decannulated alive. Forty-nine percent received noninvasive ventilation, and 25% had emergency reintubation for respiratory, neurologic, or hemodynamic reasons. Higher Simplified Acute Physiology Score II at admission (odds ratio, 0.97; 95% CI [0.95-0.99]; p = 0.008) was associated with a lower probability of extubation, whereas cannulation in cardiac surgery ICU (odds ratio, 3.14; 95% CI [1.21-8.14]; p = 0.018) was associated with an increased probability. Baseline characteristics were well balanced after propensity score overlap weighting. The number of ICU-free days within 30 days of extracorporeal membrane oxygenation decannulation was significantly higher among extubated patients compared with nonextubated patients (22 d [11-26 d] vs 18 d [7-25 d], respectively; p = 0.036). There were no differences in other outcomes including ventilator-associated pneumonia (odds ratio, 0.96; 95% CI [0.51-1.82]; p = 0.90) and all-cause mortality within 30 days of extracorporeal membrane oxygenation decannulation (5% vs 17%; hazard ratio, 0.54; 95% CI [0.19-1.59]; p = 0.27).As a secondary analysis, outcomes were compared in the overall cohort of 641 venoarterial extracorporeal membrane oxygenation-supported patients. Results were consistent with the primary analysis as extubated patients had a higher number of ICU-free days (18 d [0-24 d] vs 0 d [0-18 d], respectively; < 0.001) and a lower risk of death within 30 days of extracorporeal membrane oxygenation cannulation (hazard ratio, 0.45; 95% CI [0.29-0.71]; p = 0.001).

CONCLUSIONS

Extubation during venoarterial-extracorporeal membrane oxygenation support is safe, feasible, and associated with greater ICU-free days.

Extubating to Noninvasive Ventilation: Noninvasive Ventilation from Intensive Care Unit to Home

Weaning to noninvasive ventilation in intensive care unit and bridging the patients to home with respiratory support is evolving as the technology of noninvasive ventilation is improving. In patients with chronic obstructive pulmonary disease exacerbation, timing of initiation of noninvasive ventilation is the key, as persistently hypercapnic patients show benefits. High-intensity pressure support seems to do better in comparison to low-intensity pressure support. In patients with obesity and hypercapnia, obesity hypoventilation cannot be ruled out especially in an inpatient setting, and it is crucial that these patients are discharged with noninvasive ventilation.

Benefits of High-Flow Nasal Cannula Therapy for Acute Pulmonary Edema in Patients with Heart Failure in the Emergency Department: A Prospective Multi-Center Randomized Controlled Trial

Heart failure patients with pulmonary edema presenting to the emergency department (ED) require an effective approach to deliver sufficient oxygen and reduce the rate of intubation and mechanical ventilation in the ED; conventional oxygen therapy has proven ineffective in delivering enough oxygen to the tissues. We aimed to identify whether high-flow nasal cannula (HFNC) therapy over time improved the respiratory rate (RR), lactate clearance, and certain arterial blood gas (ABG) parameters, in comparison with conventional oxygen therapy, in patients with cardiogenic pulmonary edema. This prospective, multi-institutional, and interventional study (clinical trial, reference KCT0004578) conducted between 2016 and 2019 included adult patients diagnosed with heart failure within the previous year and pulmonary edema confirmed at admission. Patients were randomly assigned to the conventional or HFNC group and treated with the goal of maintaining oxygen saturation (SpO₂) ≥ 93. We obtained RR, SpO₂, lactate levels, and ABG parameters at baseline and 30 and 60 min after randomization. All parameters showed greater improvement with HFNC therapy than with conventional therapy. Significant changes in ABG parameters were achieved within 30 min. HFNC therapy could therefore be considered as initial oxygen therapy. Physicians may consider advanced ventilation if there is no significant improvement in ABG parameters within 30 min of HFNC therapy.

Noninvasive Positive Pressure Ventilation for Acute Decompensated Heart Failure

Noninvasive positive pressure ventilation (NIPPV), which can be applied without endotracheal airway or tracheostomy, has been used as the first-line device for patients with acute decompensated heart failure (ADHF) and cardiogenic pulmonary edema. Positive airway pressure (PAP) devices include continuous PAP, bilevel PAP, and adaptive servoventilation. NIPPV can provide favorable physiologic benefits, including improving oxygenation, respiratory mechanics, and pulmonary and systemic hemodynamics. It can also reduce the intubation rate and improve clinical symptoms, resulting in good quality of life and mortality.

Efficacy of continuous positive airway pressure in casualties suffering from primary blast lung injury: A modeling study

Primary blast lung injury is the most important component of a multisystem syndrome of injury that results from exposure to an explosive shockwave. The majority of such casualties require ventilation in an intensive care unit. We describe the use of a novel primary blast lung injury simulator to evaluate the potential efficacy of continuous positive airway pressure in 6 in silico casualties over 24 hours after injury. Our results suggest that primary blast lung injury is a form of acute lung injury that can be effectively managed with continuous positive airway pressure. In austere environments or in circumstances where medical resources are overwhelmed, continuous positive airway pressure using ambient air may be of benefit.

Indications for Non-Invasive Ventilation in Respiratory Failure

BACKGROUND

Non-invasive ventilation (NIV) is increasingly being used to treat episodes of acute respiratory failure not only in critical care and respiratory wards, but also in emergency departments.

AIM

Aim of this review is to summarize the current indications for the management of NIV for respiratory failure.

METHODS

Current literature about the topic was reviewed and critically reported to describe the rationale and physiologic advantages of NIV in various situations of respiratory failure.

RESULTS

Early NIV use is commonly associated with the significant decrease in endotracheal intubation rate, the incidence of infective complications (especially ventilatory associated pneumonia), Intensive Care Units and the length of hospital stay and, in selected conditions, also in mortality rates. Severe acute exacerbation of chronic obstructive pulmonary disease (pH<7.35 and relative hypercarbia) and acute cardiogenic pulmonary oedema are the most common NIV indications; in these conditions NIV advantages are clearly documented. Not so evident are the NIV benefits in hypoxaemic respiratory failure occurring without prior chronic respiratory disease (De novo respiratory failure). One recent randomized control trial reported in hypoxaemic respiratory failure a survival benefit of high-flow nasal cannulae over standard oxygen therapy and bilevel NIV. Evidence suggests the advantages of NIV also in respiratory failure in immunocompromised patients or chest trauma patients. Use during a pandemic event has been assessed in several observational studies but remains controversial; there also is not sufficient evidence to support the use of NIV treatment in acute asthma exacerbation.

CONCLUSION

NIV eliminates morbidity related to the endotracheal tube (loss of airway defense mechanism with increased risk of pneumonia) and in selected conditions (COPD exacerbation, acute cardiogenic pulmonary edema, immunosuppressed patients with pulmonary infiltrates and hypoxia) is clearly associated with a better outcome in comparison to conventional invasive ventilation. However, NIV is associated with complications, especially minor complications related to interface. Major complications like aspiration pneumonia, barotrauma and hypotension are infrequent.

Early decongestive therapy versus high-flow nasal cannula for the prevention of adverse clinical events in patients with acute cardiogenic pulmonary edema

Background

Few studies have investigated the role of decongestive therapy and high-flow nasal cannula (HFNC) in preventing reintubation and in-hospital mortality in patients with acute cardiogenic pulmonary edema (ACPE).

Methods

Data from patients with ACPE who were weaned from mechanical ventilation in the cardiac intensive care unit between January 2013 and December 2017 were retrospectively evaluated. All patients were treated with HFNC or conventional oxygen therapy (COT), such as a nasal cannula or venturi mask, immediately after extubation. Decongestive therapy (intravenous furosemide infusion) was administered at the discretion of the attending physician.

Results

Of 212 patients treated during the study period, 47 were excluded due to recent open-heart surgery and two, due to insufficient clinical data. The remaining 163 patients had a mean age of 67.4±14.3 years, and 92 (56.4%) were male; 44 patients received HFNC, and 119 COT. Mean weight loss within 72 hours of extubation was -0.86±2.03 kg. A total of 38 patients (23.3%) required reintubation, 21 of whom (12.9%) required reintubation within 72 hours of extubation. In-hospital mortality occurred in 16 patients (9.8%). Multivariate analysis showed that weight increase within 72 hours of extubation was independent determinants of reintubation (OR =1.7; 95% CI: 1.2-2.2; P<0.001) and in-hospital mortality (OR =1.5; 95% CI: 1.1-2.1; P=0.005). The use of HFNC was not associated with reintubation or in-hospital mortality.

Conclusions

Our findings indicate that early weight loss resulted in reduced reintubation and in-hospital mortality in patients with ACPE. However, HFNC and COT did not differ in the prevention of reintubation and in-hospital mortality. Therefore, aggressive decongestive therapy, rather than HFNC, should be considered early after extubation.

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.

Ventilação não invasiva na unidade de terapia intensiva de um hospital universitário: características relacionadas ao sucesso e insucesso

RESUMO O objetivo deste estudo foi descrever características de sucesso e insucesso do uso da ventilação não invasiva (VNI) na unidade de terapia intensiva (UTI) de um hospital universitário. Trata-se de um estudo observacional prospectivo no qual foram incluídos 75 pacientes, com idade média de 58,3±18,8 anos. Desses, doze necessitaram do uso da VNI por mais de uma vez, totalizando 92 utilizações. Evidenciou-se que, delas, a taxa de sucesso foi de 60,9% (56). O grupo insucesso apresentou mais indivíduos do sexo masculino (p=0,006) e número maior de pacientes com diagnóstico de infecção extrapulmonar (p=0,012). Não foram encontradas diferenças entre os grupos de sucesso e insucesso nos quesitos de modo, modelo, máscara, tempo total de permanência e razões para a instalação da VNI. No grupo insucesso, a pressão positiva inspiratória nas vias aéreas (Ipap) e o volume corrente (VC) foram superiores (p=0,029 e p=0,011, respectivamente). A saturação periférica de oxigênio (p=0,047), o pH (p=0,004), base excess (p=0,006) e o bicarbonato (p=0,013) apresentaram valores inferiores. Concluiu-se que os indivíduos do sexo masculino com diagnóstico de infecção extrapulmonar e que evoluíram com acidose metabólica evoluíram com mais insucesso na utilização da VNI. Esses, necessitaram de parâmetros elevados de Ipap e VC.

Clinical efficacy of high-flow oxygen therapy through nasal cannula in patients with acute heart failure

Background

High-flow oxygen therapy through nasal cannula (HFNC) could reduce intubation rate and mortality rate among patients with acute respiratory failure. We evaluated the physiological responses and clinical outcomes of HFNC in patients with acute heart failure (AHF).

Methods

A retrospective cohort analysis was performed in single medical tertiary center. Patients with AHF who had a progressive hypoxemia after oxygenation via facemask were divided into intubation group and HFNC group. We analyzed the physiological responses and in-hospital clinical outcomes between two groups.

Results

Seventy-three patients of intubation group and 76 patients of HFNC group were included. Baseline characteristics were well-balanced between two groups. There were no differences in changes of mean arterial pressure, heart rate, and pulse oxygen saturation during the first 6 hours. Among HFNC group, 66 of 76 patients (86.8%) were successfully recovered from progressive hypoxemia without endotracheal intubation, and there were no differences in in-hospital clinical outcomes between two groups.

Conclusions

This study showed HFNC group had a similar result of improvement of oxygen saturation and in-hospital clinical outcomes compared with intubation group in AHF. Present study supported HFNC could be considered as initial choice of oxygen therapy in selected patients of AHF.

Non-invasive positive pressure ventilation in lung transplant recipients with acute respiratory failure: Beyond the perioperative period

PURPOSE

The purpose of this study is to evaluate outcomes in MICU lung transplant recipients with acute respiratory failure treated with non-invasive positive pressure ventilation (NPPV) and identify factors associated with NPPV failure (need for intubation).

METHODS

Retrospective chart review of all lung transplant recipients who were admitted with acute respiratory failure to the MICU from January 2009-August 2016 was completed. Logistic regression analysis was performed to determine which factors were independently associated with NPPV failure.

RESULTS

Of 156 patients included in the study, 125 (80.1%) were tried on NPPV. Sixty-eight (54.4%) were managed successfully with NPPV with a hospital survival rate of 94.1%. Subjects who failed NPPV had higher hospital mortality, similar to those intubated from the outset (15 [48.3%]; 22 [38.6%], p = .37). In multivariate analyses, APACHE III scores >78 (9.717 [3.346, 28.22]) and PaO2/FiO2 ≤ 151 (4.54 [1.72, 11.99]) were associated with greater likelihood of NPPV failure. There was no difference in NPPV failure based on the presence of BOS. In patients with high severity of illness, there was no difference in mortality between initial IMV and NPPV failure when stratified on the basis of hypoxemia (PaO2/FiO2 > 151, p-value 0.34; PaO2/FiO2 ≤ 151, p-value 0.99).

CONCLUSIONS

NPPV is a viable option for lung transplant recipients with acute respiratory failure. Extreme caution should be exercised when used in patients with high severity of illness (APACHE III >78) and/or severe hypoxemia (PaO2/FiO2 ≤ 151).

The use of home non-invasive ventilation and the reduction of inhospital mortality of patients with respiratory failure

OBJECTIVES

To establish the relationship between the use of home non-invasive ventilation (NIV) and inhospital mortality in people admitted due to exacerbation of their respiratory disease.

METHODS

Retrospective cohort study with 191 cases of patients attended at the emergency department of the Reina Sofía General University Hospital in Murcia due to ARF of any cause and who required NIV as supportive treatment.

RESULTS

Mortality among patients using NIV as routine home treatment was 6.45%, compared to 20.1% among those who did not use it (P<.05).

CONCLUSIONS

routine domiciliary treatment with NIV has been shown to be a protective factor against inpatient hospital mortality for patients who underwent NIV during their admission, through the emergency department, for acute respiratory failure or acute chronic disease, regardless of the triggering pathology.

Pressure support ventilation vs Continuous positive airway pressure for treating of acute cardiogenic pulmonary edema: A pilot study

Non-invasive ventilation is usually adopted as a support to medical therapy in patients with acute pulmonary edema, but which modality between Pressure Support Ventilation (PSV) and Continuous Positive Airway Pressure (CPAP) has better favourable effects is not been yet well known. Aim of this observational study was to provide data on these different non-invasive ventilation modalities in the management of acute cardiogenic pulmonary edema. One-hundred-fifty-three patients consecutively admitted to the Emergency Room of two different Center were enrolled and randomly assigned to CPAP or PSV. Data relative to mortality, need of endotracheal intubation, sequential blood gas analysis were compared. Furthermore, there were no significant differences regarding mortality in the two groups, but patients treated with PSV had a significant lower rate of endotracheal intubation and a higher improvement of blood gas analyses parameters. In conclusion, our data support only a slight advantage in favour to PSV versus CPAP.

Hemodynamic Effects of Noninvasive Positive-Pressure Ventilation Assessed Using Transthoracic Echocardiography

Aims:

The aim of this study is to measure the effect of positive-pressure ventilation on heart chamber dimensions, left ventricular (LV) systolic function, LV diastolic function, right ventricular (RV) systolic function, and RV pressure using transthoracic echocardiography.

Settings and Design:

This is a prospective study in a single secondary health-care center.

Materials and Methods:

A total of 107 patients with obstructive sleep apnea on continuous positive airway pressure (CPAP) therapy were recruited as participants between April and September 2016. Transthoracic echocardiography was performed twice on each participant, before and 15 min after, they used their own CPAP machines, and the echocardiography parameters of both scans were compared.

Statistical Analysis Used:

The parametric paired t-test was used to compare heart chamber dimensions, left heart diastolic function, left heart systolic function, right heart systolic function, and right heart pressure effect, without and with CPAP. These data were further examined among several subgroups defined by CPAP when the cutoff point was set at 8 cmH₂O and 10 cmH₂O. The level of significance was set at 0.05. Statistical analyses were performed using IBM SPSS version 22 (IBM, Armonk, NY, USA).

Results:

There were statistically significant reductions, after the application of CPAP, in the heart dimensions, and LV and RV systolic function. There were no significant changes in diastolic function. Concerning right heart pressure, with CPAP, there was a significant increase in the inferior vena cava (IVC) diameter and there was also a significant decrease in IVC variability from 44.56% ± 14.86% to 36.12% ± 11.42%. The maximum velocity of tricuspid regurgitation (TR) decreased significantly from 180.66 ± 6.95 cm/s to 142.30 ± 52.73 cm/s. Such changes were observed in both low and high CPAP subgroups.

Conclusions:

When placed on positive pressure, the clinically significant change in IVC diameter and variability and change in trans-TR velocity mean that it would be inaccurate to predict right heart chamber pressure through echocardiogram. Alternative methods for predicting right heart pressure are recommended.

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.

NIV by an interdisciplinary respiratory care team in severe respiratory failure in the emergency department limited to day time hours

Non-invasive ventilatory support is frequently used in patients with severe respiratory failure (SRF), but is often limited to intensive care units (ICU). We hypothesized that an instantaneous short course of NIV (up to 2 h), limited to regular working hours as an additional therapy on the emergency department (ED) would be feasible and could improve patient´s dyspnoea measured by respiratory rate and Borg visual dyspnea scale. NIV was set up by an interdisciplinary respiratory care team. Outside these predefined hours NIV was performed in the ICU. This is an observational cohort study over 1 year in the ED in a non-university hospital. Fifty-one % of medical emergencies arrived during regular working hours (5475 of 10,718 patients). In total, 63 patients were treated with instantaneous NIV. Door to NIV in the ED was 56 (31-97) min, door to ICU outside regular working hours was 84 (57-166) min. Within 1 h of NIV, the respiratory rate decreased from 30/min (25-35) to 19/min (14-24, p < 0.001), the Borg dyspnoea scale improved from 7 (5-8) to 2 (0-3, p < 0.001). In hypercapnic patients, the blood-pH increased from 7.29 (7.24-7.33) to 7.35 (7.29-7.40) and the pCO₂ dropped from 8.82 (8.13-10.15) to 7.45 (6.60-8.75) kPa. In patients with SRF of varying origin, instantaneous NIV in the ED during regular working hours was feasible in a non-university hospital setting, and rapidly and significantly alleviated dyspnoea and reduced respiratory rate. This approach proved to be useful as a bridge to the ICU as well as an efficient palliative dyspnoea treatment.

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.

The comparative effectiveness of noninvasive and invasive ventilation in patients with pneumonia

PURPOSE

To compare the outcomes of patients hospitalized with pneumonia treated with noninvasive ventilation (NIV) and invasive mechanical ventilation (IMV).

MATERIALS AND METHODS

Using the HealthFacts multihospital electronic medical record database, we included patients hospitalized with a diagnosis of pneumonia and treated with NIV or IMV. We developed a propensity model for receipt of initial NIV and assessed the outcomes in a propensity-matched cohort, and in a covariate adjusted and propensity score weighted models.

RESULTS

Among 3971 ventilated patients, 1109 (27.9%) were initially treated with NIV. Patients treated with NIV were older, had lower acuity of illness score, and were more likely to have congestive heart failure and chronic pulmonary disease. Mortality was 15.8%, 29.8% and 25.9.0% among patients treated with initial NIV, initial IMV and among those with NIV failure. In the propensity matched analysis, the risk of death was lower in patients treated with NIV (relative risk: 0.71, 95% CI: 0.59-0.85). Subgroup analysis showed that NIV was beneficial among patients with cardiopulmonary comorbidities (relative risk 0.59, 95% CI: 0.47-0.75) but not in those without (relative risk 0.96, 95% CI: 0.74-0.1.25)NIV failure was significantly (p=0.002) more common in patients without cardiopulmonary conditions (21.3%) compared to those with these conditions (13.8%).

CONCLUSIONS

Initial NIV was associated with better survival among the subgroup of patients hospitalized with pneumonia who had COPD or heart failure. Patients who failed NIV had high in-hospital mortality, emphasizing the importance of careful patient selection monitoring when managing severe pneumonia with NIV.

Prehospital treatment with continuous positive airway pressure in patients with acute respiratory failure: a regional observational study

BACKGROUND

Patients with acute respiratory failure are at risk of deterioration during prehospital transport. Ventilatory support with continuous positive airway pressure (CPAP) can be initiated in the prehospital setting. The objective of the study is to evaluate adherence to treatment and effectiveness of CPAP as an addition to standard care.

METHODS

In North Denmark Region, patients with acute respiratory failure, whom paramedics assessed as suffering from acute cardiopulmonary oedema, acute exacerbation of chronic obstructive pulmonary disease or asthma were treated with CPAP using 100 % O2 from 1 March 2014 to 3 May 2015. Adherence to treatment was evaluated by number of adverse events and discontinuation of treatment. Intensive care admissions and mortality were reported in this cohort. Effectiveness was evaluated by changes in peripheral oxygen saturation (SpO2) and respiratory rate during transport and compared to a historical control (non-CPAP) group treated with standard care only. Values were compared by hypothesis testing and linear modelling of SpO2 on arrival at scene and ΔSpO2 stratified according to treatment group.

RESULTS

In fourteen months, 171 patients were treated with CPAP (mean treatment time 35 ± 18 min). Adverse events were reported in 15 patients (9 %), hereof six discontinued CPAP due to hypotension, nausea or worsening dyspnoea. One serious adverse event was reported, a suspected pneumothorax treated adequately by an anaesthesiologist called from a mobile emergency care unit. Among CPAP patients, 45 (27 %) were admitted to an intensive care unit and 24 (14 %) died before hospital discharge. The non-CPAP group consisted of 739 patients. From arrival at scene to arrival at hospital, CPAP patients had a larger increase in SpO2 than non-CPAP patients (87 to 96 % versus 92 to 96 %, p < 0.01) and a larger decrease in respiratory rate (32 to 25 versus 28 to 24 breaths/min, p < 0.01). In a linear model, CPAP was superior to non-CPAP in patients with initial SpO2 ≤90 % (p < 0.05). One CPAP patient (0.6 %) and eight non-CPAP patients (1.1 %) were intubated in the prehospital setting.

DISCUSSION

The study design reflects the daily prehospital working environment including long transport timesand paramedics educated in treating symptoms of acute respiratory failure, rather than treating one specific diagnosis. The study population was included consecutively and few patients were lost to follow-up. However, the study was too small to allow assessment of any effect of prehospital CPAP on mortality, nor could the effectiveness in specific disease conditions be examined.

CONCLUSIONS

In an emergency medical service including physician backup, adherence to CPAP treatment administered by paramedics was high and treatment was effective in patients with acute respiratory failure.

Cardiopulmonary Interactions in Children with Heart Failure

Cardiopulmonary interactions are present but inconsequential in humans with normal cardiac and respiratory function; however, in the presence of significant impairment in either system, the importance of the interplay between cardiovascular and pulmonary systems cannot be overstated. This review will discuss the physiologic underpinnings and consequences of these interactions in patients with heart failure.

Cardiopulmonary Interactions

OBJECTIVES

The objectives of this review are to discuss the mechanisms by which respiration impacts cardiovascular function and vice versa, with an emphasis on the impact of these interactions in pediatric cardiac critical care.

DATA SOURCE

A search of MEDLINE was conducted using PubMed.

CONCLUSIONS

In the presence of underlying cardiac and respiratory disease, the interplay between these two systems is significant and plays a pivotal role in the pathophysiology of acute and chronic phases of a wide spectrum of diseases. An understanding of these relationships is essential to optimizing the care of critically ill patients.

Approach to economic analysis in critical care

There are 4 general economic analyses used in health care: cost minimization, cost-benefit, cost-effectiveness, and cost utility. In this review, we provide an overview of each of these analyses and examine their appropriateness and effectiveness in assessing critical care costs. In the intensive care unit setting, it is particularly important to consider the patients' quality of life following the treatment of critical illness and to adopt a societal perspective when conducting economic analyses. Therefore, of the 4 economic analyses we cover, we recommend the use of cost-effectiveness and cost utility analyses.

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.

Mechanical Ventilation and Clinical Outcomes in Patients with Acute Myocardial Infarction: A Retrospective Observational Study

Purpose

Patients with acute myocardial infarction (AMI) and respiratory impairment may be treated with either invasive or non-invasive mechanical ventilation (MV). However, there has been little testing of non-invasive MV in the setting of AMI. Our objective was to evaluate the incidence and associated clinical outcomes of patients with AMI who were treated with non-invasive or invasive MV.

Methods

This was a retrospective observational study in which consecutive patients with AMI (n = 1610) were enrolled. The association between exclusively non-invasive MV, invasive MV and outcomes was assessed by multivariable models.

Results

Mechanical ventilation was used in 293 patients (54% invasive and 46% exclusively non-invasive). In-hospital mortality rates for patients without MV, with exclusively non-invasive MV, and with invasive MV were 4.0%, 8.8%, and 39.5%, respectively (P<0.001). The median lengths of hospital stay were 6 (5.8–6.2), 13 (11.2–4.7), and 28 (18.0–37.9) days, respectively (P<0.001). Exclusively non-invasive MV was not associated with in-hospital death (adjusted HR = 0.90, 95% CI 0.40–1.99, P = 0.79). Invasive MV was strongly associated with a higher risk of in-hospital death (adjusted HR = 3.07, 95% CI 1.79–5.26, P<0.001).

Conclusions

In AMI setting, 18% of the patients required MV. Almost half of these patients were treated with exclusively non-invasive strategies with a favorable prognosis, while patients who needed to be treated invasively had a three-fold increase in the risk of death. Future prospective randomized trials are needed to compare the effectiveness of invasive and non-invasive MV for the initial approach of respiratory failure in AMI patients.

Performance of noninvasive ventilation in acute respiratory failure in critically ill patients: a prospective, observational, cohort study

BACKGROUND

Noninvasive ventilation (NIV) is used in critically ill patients with acute respiratory failure (ARF) to avoid endotracheal intubation. However, the impact of NIV use on ARF patient's outcomes is still unclear. Our objectives were to evaluate the rate of NIV failure in hypoxemic patients with an arterial carbon dioxide partial pressure (PaCO2) < 45 mmHg or ≥ 45 mmHg at ICU admission, the predictors of NIV failure, ICU and hospital length of stay and 28-day mortality.

METHODS

Prospective single center cohort study. All consecutive patients admitted to a mixed ICU during a three-month period who received NIV, except for palliative care purposes, were included in this study. Demographic data, APACHE II score, cause of ARF, number of patients that received NIV, incidence of NIV failure, length of ICU, hospital stay and mortality rate were compared between NIV failure and success groups.

RESULTS

Eighty-five from 462 patients (18.4 %) received NIV and 26/85 (30.6 %) required invasive mechanical ventilation. NIV failure patients were comparatively younger (67 ± 21 vs. 77 ± 14 years; p = 0.031), had lower arterial bicarbonate (p = 0.005), lower PaCO2 levels (p = 0.032), higher arterial lactate levels (p = 0.046) and APACHE II score (p = 0.034) compared to NIV success patients. NIV failure occurred in 25.0 % of patients with PaCO2 ≥ 45 mmHg and in 33.3 % of patients with PaCO2 < 45 mmHg (p = 0.435). NIV failure was associated with an increased risk of in-hospital death (OR 4.64, 95 % CI 1.52 to 14.18; p = 0.007) and length [median (IQR)] of ICU [12 days (8-31) vs. 2 days (1-4); p < 0.001] and hospital [30 (19-42) vs. 15 (9-33) days; p = 0.010] stay. Predictors of NIV failure included age (OR 0.96, 95 % CI 0.93 to 0.99; p = 0.007) and APACHE II score (OR 1.13, 95 % CI 1.02 to 1.25; p = 0.018).

CONCLUSION

NIV failure was associated with an increased risk of in-hospital death, ICU and hospital stay and was not affected by baseline PaCO2 levels. Patients that failed were comparatively younger and had higher APACHE II score, suggesting the need for a careful selection of patients that might benefit from NIV. A well-designed study on the impact of a short monitored NIV trial on outcomes is needed.

High-Flow Nasal Cannula Therapy for Acute Hypoxemic Respiratory Failure in Adults: A Retrospective Analysis

OBJECTIVE

High-flow nasal cannula (HFNC) therapy is an oxygen delivery system. However, evidence regarding the clinical applications of HFNC is still emerging. We herein evaluated the clinical predictors of HFNC therapy success for adult patients with acute hypoxemic respiratory failure.

METHODS

We retrospectively reviewed the medical records of the subjects with acute hypoxemic respiratory failure supported by HFNC therapy in the medical intensive care unit between July 2011 and March 2013. Therapy success was defined as the avoidance of intubation. The patients' baseline characteristics and the serial changes in the respiratory parameters after HFNC therapy at 1 and 24 hours were measured.

RESULTS

Of the 75 eligible patients, 62.7% successfully avoided intubation. Overall, HFNC therapy significantly improved the physiologic parameters, such as partial pressure of arterial oxygen (PaO2), saturation of arterial oxygen (SaO2), respiratory rate (RR), and heart rate (HR), throughout the first 24 hours. After the adjustment for the other clinical variables, Acute Physiology and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA), cardiogenic pulmonary edema, and PaO2 improvement at 1 and 24 hours were associated with therapy success. The overall intensive care unit (ICU) mortality was 25.3%. However, out of 37.3% of the patients who required intubation, the ICU mortality in this proportion of patients was 67.9%. The ICU mortality in the therapy failure group was associated with the use of a vasopressor and a limited PaO2 improvement at 1 hour.

CONCLUSION

HFNC therapy showed a good compliance and the improvement of the physiologic parameters in an adult population. The failure to improve oxygenation within 24 hours was a useful predictor of intubation. Among the failure group, the vasopressor use and failed oxygenation improvement were associated with ICU mortality.

Effect of PEEP on phosgene-induced lung edema: pilot study on dogs using protective ventilation strategies

Various therapeutic regimes have been proposed for treatment of phosgene-induced acute lung injury (P-ALI). Most of these treatments rely on late-stage supportive measures to maintain the oxygenation of the lung. This exploratory proof-of-concept study on Beagle dogs focused on protective positive end-expiratory pressure (PEEP) ventilation, initiated early at the yet asymptomatic stage after phosgene exposure. Conscious, spontaneously breathing dogs were head-only exposed to a potentially lethal inhalation dose of phosgene (870 ppm × min). Shortly after exposure, the dogs were anesthetized, intubated and then subjected to mechanical ventilation (PEEP; tidal volume (VT)=10-12 mL/kg body weight, 40 breaths/min) at 0, 4, or 12 cm H2O over a post-exposure period of 8h (one dog per setting). For reference, one additional dog received the same dose of phosgene without anesthesia and mechanical ventilation. Time-course changes of hematocrit, leukocytes, and thrombocytes were determined in peripheral blood. At necropsy, changes lung weights, bronchoalveolar lavage, and histology were used to assess the efficacy of treatment. The most salient outcome in the non-ventilated dog was a time-related hemoconcentration and leukocytosis and autopsy findings suggestive of pulmonary congestion and edema. The pulmonary epithelium of the major airways was generally intact; however, in their lumen inflammatory cells, cellular debris and mucus were present. Relative to the dog receiving no intervention, the lung edema was markedly alleviated by PEEP at both 4 and 12 cm H2O but not at 0 cm H2O PEEP. In summary, the time-dependent progression into a life-threatening pulmonary edema can effectively be suppressed by protective, low-pressure PEEP when implemented early enough after exposure to phosgene. However, due to the exploratory nature of this study, the findings may suggest an association between PEEP and protection from pulmonary edema. However, definite conclusions and recommendations cannot be made yet based upon the small sample size and the limited variables examined.

New therapeutic options in heart failure. What's on the horizon? An overview

Heart failure is a complex clinical syndrome responsible for high morbidity and mortality in the world. Despite advances in the management of heart failure, the prognosis of these patients remains poor and there is a critical need for new treatment strategies improving the clinical outcomes. New approaches in heart failure therapies target cellular mechanisms, as well as mechanical and structural aspects of heart failure that are not addressed by recent therapies. These include abnormalities in molecular mechanisms, electrical conduction and ventricular remodeling. This review presents the pathophysiological basis, mechanisms of action and available clinical efficacy and safety data of drugs and mechanical therapies that are currently under development.

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.

Open circuit mouthpiece ventilation: Concise clinical review

In 2013 new "mouthpiece ventilation" modes are being introduced to commercially available portable ventilators. Despite this, there is little knowledge of how to use noninvasive intermittent positive pressure ventilation (NIV) as opposed to bi-level positive airway pressure (PAP) and both have almost exclusively been reported to have been used via nasal or oro-nasal interfaces rather than via a simple mouthpiece. Non-invasive ventilation is often reported as failing because of airway secretion encumbrance, because of hypercapnia due to inadequate bi-level PAP settings, or poor interface tolerance. The latter can be caused by factors such as excessive pressure on the face from poor fit, excessive oral air leak, anxiety, claustrophobia, and patient-ventilator dys-synchrony. Thus, the interface plays a crucial role in tolerance and effectiveness. Interfaces that cover the nose and/or nose and mouth (oro-nasal) are the most commonly used but are more likely to cause skin breakdown and claustrophobia. Most associated drawbacks can be avoided by using mouthpiece NIV. Open-circuit mouthpiece NIV is being used by large populations in some centers for daytime ventilatory support and complements nocturnal NIV via "mask" interfaces for nocturnal ventilatory support. Mouthpiece NIV is also being used for sleep with the mouthpiece fixed in place by a lip-covering flange. Small 15 and 22mm angled mouthpieces and straw-type mouthpieces are the most commonly used. NIV via mouthpiece is being used as an effective alternative to ventilatory support via tracheostomy tube (TMV) and is associated with a reduced risk of pneumonias and other respiratory complications. Its use facilitates "air-stacking" to improve cough, speech, and pulmonary compliance, all of which better maintain quality of life for patients with neuromuscular diseases (NMDs) than the invasive alternatives. Considering these benefits and the new availability of mouthpiece ventilator modes, wider knowledge of this technique is now warranted. This review highlights the indications, techniques, advantages and disadvantages of mouthpiece NIV.

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.

Ventilator management in the cardiac intensive care unit

Patients admitted to the Cardiac Intensive Care Unit (CICU) are of increasing complexity and often require ventilatory support. A deep understanding of respiratory physiology and the interactions between the cardiovascular and respiratory systems is essential. Ventilatory support should be tailored to the specific patient condition, ensuring effective minute ventilation, reducing work of breathing and minimizing adverse hemodynamic effects. The weaning process can stress the cardiovascular system and cardiac failure is a common cause of failure to wean. Identification of patients likely to fail and prompt pre-emptive intervention is crucial for successful weaning and avoiding complications related to prolonged mechanical ventilation.

Noninvasive ventilation: practical advice

PURPOSE OF REVIEW

This critical review discusses the key points that would be of practical help for the clinician who applies noninvasive ventilation (NIV) for treatment of patients with acute respiratory failure (ARF).

RECENT FINDINGS

In recent years, the growing role of NIV in the acute care setting has led to the development of technical innovations to overcome the problems related to gas leakage and dead space. A considerable amount of research has been conducted to improve the quality of the devices as well as optimize ventilation modes used to administer NIV. As a result, also mechanical ventilators have been implemented with modalities aimed at delivering NIV.

SUMMARY

The success of NIV in patients with ARF depends on several factors, including the skills of the clinician, selection of patient, choice of interface, selection of ventilation mode and ventilator setting, monitoring, and the motivation of the patient. Recent advances in the understanding of the physiological aspects of using NIV through different interfaces and ventilator settings have led to improve patient-machine interaction, enhancing favorable NIV outcome.