Conventional Oxygen Therapy In Patients Research Articles

Efficacy of high-flow nasal oxygen therapy started in the emergency room versus conventional oxygen therapy in patients with acute hypoxaemic respiratory distress: protocol for a French multicentric, prospective, open and randomised superiority study protocol (HIFLOWED)

IntroductionAcute respiratory failure is a life-threatening condition frequently found in the emergency department. High-flow nasal oxygen (HFNO) is increasingly used in emergency departments for patients with hypoxaemic acute respiratory failure....

Comparison between high-flow nasal cannula and conventional oxygen therapy in COVID-19 patients: a systematic review and meta-analysis.

High-flow nasal cannula (HFNC) and conventional oxygen therapy (COT) are important respiratory support strategies for acute hypoxemic respiratory failure (AHRF) in coronavirus disease 2019 (COVID-19) patients. However, the results are conflicting for the risk of intubation with HFNC as compared to COT. We systematically synthesized the outcomes of HFNC relative to COT in COVID-19 patients with AHRF and evaluated these outcomes in relevant subpopulations. This study was designed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched PubMed, EMBASE, Web of Science, Scopus, ClinicalTrials.gov, medRxiv, BioRxiv, and the Cochrane Central Register of Controlled Trials for randomized controlled trials and observational studies that compared the efficacy of HFNC with COT in patients with COVID-19-related AHRF. Primary outcomes were intubation rate and mortality rate. Secondary outcomes were the ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2), respiratory rate, hospital length of stay, intensive care unit (ICU) length of stay, and days free from invasive mechanical ventilation. In total, 20 studies with 5732 patients were included. We found a decreased risk of requiring intubation in HFNC compared to COT [odds ratio (OR) = 0.61, 95% confidence interval (CI): 0.46-0.82, p = 0.0009, I2 = 75%]. Similarly, we found HFNC was associated with lower risk of intubation rate compared to COT in the subgroup of patients with baseline PaO2/FiO2 < 200 mmHg (OR = 0.69, 95% CI: 0.55-0.86, p = 0.0007, I2 = 45%), and who were in ICU settings at enrollment (OR = 0.57, 95% CI: 0.38-0.85, p = 0.005, I2 = 80%). HFNC was associated with an improvement of PaO2/FiO2 and respiratory rate compared to COT. The use of HFNC compared to COT did not reduce the mortality rate, days free from invasive mechanical ventilation, hospital length of stay, or ICU length of stay. Compared to COT, HFNC may decrease the need for tracheal intubation in patients with COVID-19-related AHRF, particularly among patients with baseline PaO2/FiO2 < 200 mmHg and those in ICU settings. This systematic review and meta-analysis protocol was prospectively registered with PROSPERO (no. CRD42022339072).

High-flow nasal cannula oxygen versus conventional oxygen therapy for acute respiratory failure due to COVID-19: a systematic review and meta-analysis

BackgroundThe effectiveness of high-flow nasal cannula oxygen therapy (HFNC) in patients with acute respiratory failure due to COVID-19 remains uncertain. We aimed at assessing whether HFNC is associated with reduced risk of intubation or mortality in patients with acute respiratory failure due to COVID-19 compared with conventional oxygen therapy (COT).MethodsIn this systematic review and meta-analysis, we searched MEDLINE, Embase, Web of Science, and CENTRAL databases for randomized controlled trials (RCTs) and observational studies comparing HFNC vs. COT in patients with acute respiratory failure due to COVID-19, published in English from inception to December 2022. Pediatric studies, studies that compared HFNC with a noninvasive respiratory support other than COT and those in which intubation or mortality were not reported were excluded. Two authors independently screened and selected articles for inclusion, extracted data, and assessed the risk of bias. Fixed-effects or random-effects meta-analysis were performed according to statistical heterogeneity. Primary outcomes were risk of intubation and mortality across RCTs. Effect estimates were calculated as risk ratios and 95% confidence interval (RR; 95% CI). Observational studies were used for sensitivity analyses.ResultsTwenty studies were analyzed, accounting for 8383 patients, including 6 RCTs (2509 patients) and 14 observational studies (5874 patients). By pooling the 6 RCTs, HFNC compared with COT significantly reduced the risk of intubation (RR 0.89, 95% CI 0.80 to 0.98; p = 0.02) and reduced length of stay in hospital. HFNC did not significantly reduce the risk of mortality (RR 0.93, 95% CI 0.77 to 1.11; p = 0.40).ConclusionsIn patients with acute respiratory failure due to COVID-19, HFNC reduced the need for intubation and shortened length of stay in hospital without significant decreased risk of mortality.Trial registration The study was registered on the International prospective register of systematic reviews (PROSPERO) at https://www.crd.york.ac.uk/prospero/ with the trial registration number CRD42022340035 (06/20/2022).

Effects of high flow nasal cannula following minimally invasive esophagectomy in ICU patients: A prospective pre-post study

Patients with esophageal cancer who undergo minimally invasive esophagectomy are at risk of postoperative pulmonary complications. High-flow nasal cannula oxygen therapy delivers humidified, warmed positive airway pressure but has not been applied routinely after surgery. Here, we aimed to compare high-flow nasal cannula and conventional oxygen therapy in patients with esophageal cancer during intensive care unit hospitalization 48h postoperatively. In this prospective pre- and post-intervention study, patients with esophageal cancer who underwent elective minimally invasive esophagectomy (MIE) and were extubated in the operation room and admitted to the intensive care unit postoperatively were assigned to receive either high-flow nasal cannula (HFNCO) or standard oxygen (SO) therapy. Participants in the SO group were recruited before January 2020, and those in the HFNCO group were enrolled after January 2020. The primary outcome was the difference in postoperative pulmonary complication incidence. Secondary outcomes were the occurrence of desaturation within 48h, PaO2/FiO2 within 48h, anastomotic leakage, length of intensive care unit and hospital stay, and mortality. The standard oxygen and high-flow nasal cannula oxygen groups comprised 33 and 36 patients, respectively. Baseline characteristics were comparable between groups. In the HFNCO group, postoperative pulmonary complication incidence was significantly reduced (22.2% vs 45.5%) and PaO2/FiO2 was significantly increased. No other between-group differences were observed. HFNCO therapy significantly reduced postoperative pulmonary complication incidence after elective MIE in patients with esophageal cancer without increasing the risk of anastomotic leakage.

Comparison of High-Flow Nasal Cannula with Conventional Oxygen Therapy in Patients with Hypercapnic Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis.

This study aimed to evaluate the clinical outcomes of high-flow nasal cannula (HFNC) compared with conventional oxygen therapy (COT) in patients with hypercapnic chronic obstructive pulmonary disease (COPD), including arterial partial pressure of carbon dioxide (PaCO2), arterial partial pressure of oxygen (PaO2), respiratory rate (RR), treatment failure, exacerbation rates, adverse events and comfort evaluation. PubMed, EMBASE and the Cochrane Library were retrieved from inception to September 30, 2022. Eligible trials were randomized controlled trials and crossover studies comparing HFNC and COT in hypercapnic COPD patients. Continuous variables were reported as mean and standard derivation and calculated by weighted mean differences (MD), while dichotomous variables were shown as frequency and proportion and calculated by odds ratio (OR), with the 95% confidence intervals (Cl). Statistical analysis was performed using RevMan 5.4 software. Eight studies were included, five with acute hypercapnia and three with chronic hypercapnia. In acute hypercapnic COPD, short-term HFNC reduced PaCO2 (MD -1.55, 95% CI: -2.85 to -0.25, I² = 0%, p <0.05) and treatment failure (OR 0.54, 95% CI: 0.33 to 0.88, I² = 0%, p<0.05), but there were no significant differences in PaO2 (MD -0.36, 95% CI: -2.23 to 1.52, I² = 45%, p=0.71) and RR (MD -1.07, 95% CI: -2.44 to 0.29, I² = 72%, p=0.12). In chronic hypercapnic COPD, HFNC may reduce COPD exacerbation rates, but there was no advantage in improving PaCO2 (MD -1.21, 95% CI: -3.81 to 1.39, I² = 0%, p=0.36) and PaO2 (MD 2.81, 95% CI: -1.39 to 7.02, I² = 0%, p=0.19). Compared with COT, short-term HFNC reduced PaCO2 and the need for escalating respiratory support in acute hypercapnic COPD, whereas long-term HFNC reduced COPD exacerbations rates in chronic hypercapnia. HFNC has great potential for treating hypercapnic COPD.

High-Flow Nasal Cannula Oxygen Therapy in Patients With Acute Heart Failure: A Meta-analysis

This meta-analysis compares the efficacy of high-flow nasal cannula (HFNC) with conventional oxygen therapy in patients with acute heart failure (AHF). We comprehensively searched the PubMed, Embase, Cochrane Library, Chinese Sino-Med, China National Knowledge Infrastructure, and Chinese WanFang Med Online databases and identified 9 randomized controlled trials with 689 patients that compared HFNC with conventional oxygen therapy. We found that HFNC use in patients with AHF resulted in a significant improvement in their heart rate, respiratory rate, brain natriuretic peptide level, oxygen saturation, partial pressure of oxygen, intubation rate, left ventricular ejection fraction, and length of hospitalization.

High-flow nasal cannula reduces intubation rate in patients with COVID-19 with acute respiratory failure: a meta-analysis and systematic review

ObjectiveThis study aimed to investigate the effect of high-flow nasal cannula therapy (HFNC) versus conventional oxygen therapy (COT) on intubation rate, 28-day intensive care unit (ICU) mortality, 28-day ventilator-free days...

High-flow nasal oxygen versus conventional oxygen therapy in patients with COVID-19 pneumonia and mild hypoxaemia: a randomised controlled trial

RationaleIn patients with COVID-19 pneumonia and mild hypoxaemia, the clinical benefit of high-flow nasal oxygen (HFNO) remains unclear. We aimed to examine whether HFNO compared with conventional oxygen therapy (COT)...

Modified high-flow nasal cannula oxygen therapy versus conventional oxygen therapy in patients undergoing bronchoscopy: a randomized clinical trial

BackgroundHypoxemia frequently occurs during bronchoscopy. High-flow nasal cannula (HFNC) oxygen therapy may be a feasible alternative to prevent the deterioration of gas exchange during bronchoscopy. With the convenience of clinical use in mind, we modified an HFNC using a single cannula. This clinical trial was designed to test the hypothesis that a modified HFNC would decrease the proportion of patients with a single moment of peripheral arterial oxygen saturation (SpO2) < 90% during bronchoscopy.MethodsIn this single-center, prospective randomized controlled trial, hospitalized patients in the respiratory department in need of diagnostic bronchoscopy were randomly assigned to a modified HFNC oxygen therapy group or a conventional oxygen therapy (COT) group. The primary outcome was the proportion of patients with a single moment of SpO2 < 90% during bronchoscopy.ResultsEight hundred and twelve patients were randomized to the modified HFNC (n = 406) or COT (n = 406) group. Twenty-four patients were unable to cooperate or comply with bronchoscopy. Thus, 788 patients were included in the analysis. The proportion of patients with a single moment of SpO2 < 90% during bronchoscopy in the modified HFNC group was significantly lower than that in the COT group (12.5% vs. 28.8%, p < 0.001). There were no significant differences in the fraction of inspired oxygen between the two groups. The lowest SpO2 during bronchoscopy and 5 min after bronchoscopy in the modified HFNC group was significantly higher than that in the COT group. Multivariate analysis showed that a baseline forced vital capacity (FVC) < 2.7 L (OR, 0.276; 95% CI, 0.083–0.919, p = 0.036) and a volume of fluid instilled > 60 ml (OR, 1.034; 95% CI, 1.002–1.067, p = 0.036) were independent risk factors for hypoxemia during bronchoscopy in the modified HFNC group.ConclusionsA modified HFNC could decrease the proportion of patients with a single moment of SpO2 < 90% during bronchoscopy. A lower baseline FVC and large-volume bronchoalveolar lavage may predict desaturation during bronchoscopy when using a modified HFNC.Trial registration ClinicalTrials. Gov: NCT02606188. Registered 17 November 2015.

A postoperative comparison of high-flow nasal cannula therapy and conventional oxygen therapy for esophageal cancer patients.

Hypoxaemia in post-surgical patients of esophageal cancer (EC) is common in thoracic departments. However, few studies have investigated the role of high-flow nasal cannula (HFNC) compared with conventional oxygen therapy (COT). A retrospective study was implemented to enroll hypoxemic patients after esophagectomy who were treated by HFNC or COT immediately after extubation between January 2019 and December 2019. We compared the effect of HFNC or COT in patients regarding the vital signs and arterial blood gases, the incidence of anastomotic leakage, postoperative pulmonary complications (PPCs), sore throat/nose, and reintubation, length of stay, and sputum production. We also 3D reconstructed the postoperative chest CT, and compared the amount of lung volume loss caused by PPCs (pneumothorax, atelectasis, pulmonary consolidation and pleural effusion) between the two groups. Compared to patients in COT group, sore throat/nose in HFNC group was lower, the sputum production was higher, and the total hospital stay was shorter. Compared to COT, HFNC treatment decreased systolic blood pressure (SBP) at day 1, diastolic blood pressure (DBP) at day 1-4, and heart rate (HR) at day 2-4, increased arterial partial pressure of oxygen (PaO2) at day 1-4, and arterial oxygen saturation (SaO2%) at day 1-2. In addition, the rate of PPCs and anastomotic leakage in HFNC group were lower than those in COT group. Compared to COT, HFNC treatment significantly decreased the amount of lung volume loss caused by PPCs. HFNC can improve the hypoxemia of patients after esophagectomy, increase the flow of sputum, reduce the incidence of PPC and anastomotic leakage.

Noninvasive ventilation versus conventional oxygen therapy after extubation failure in high-risk patients in an intensive care unit: a pragmatic clinical trial.

ObjetivoDeterminar la efectividad de la ventilación no invasiva frente a oxigenoterapia convencional en pacientes con insuficiencia respiratoria aguda tras fracaso de la extubación.MétodosEnsayo clínico pragmático realizado una unidad de cuidados intensivos de marzo de 2009 a septiembre de 2016. Se incluyeron pacientes sometidos a ventilación mecánica > 24 horas, y que desarrollaron insuficiencia respiratoria aguda tras extubación programada, siendo asignados a ventilación no invasiva u oxigenoterapia convencional. El objetivo primario fue reducir la tasa de reintubación. Los objetivos secundarios fueron: mejora de los parámetros respiratorios, reducción de las complicaciones, de la duración de la ventilación mecánica, de la estancia en unidad de cuidados intensivos y hospitalaria, así como de la mortalidad en unidad de cuidados intensivos, hospitalaria y a los 90 días. También se analizaron los factores relacionados con la reintubación.ResultadosDe un total de 2.574 pacientes, se analizaron 77 (38 en el grupo de ventilación no invasiva y 39 en el grupo de oxigenoterapia convencional). La ventilación no invasiva redujo la frecuencia respiratoria y cardíaca más rápidamente que la oxigenoterapia convencional. La reintubación fue menor en el grupo de ventilación no invasiva [12 (32%) versus 22(56%) en grupo oxigenoterapia convencional, RR 0,58 (IC95% 0,34 - 0,97), p = 0,039], el resto de los parámetros no mostró diferencias significativas. En el análisis multivariante, la ventilación no invasiva prevenía la reintubación [OR 0,17 (IC95% 0,05 - 0,56), p = 0,004], mientras que el fracaso hepático previo a la extubación y la incapacidad para mantener vía aérea permeable predisponían a la reintubación.ConclusiónEl empleo de la ventilación no invasiva en pacientes que fracasa la extubación podría ser beneficiosa frente a la oxigenoterapia convencional.

Comparison of Postextubation Outcomes Associated with High-Flow Nasal Cannula vs. Conventional Oxygen Therapy in Patients at High Risk of Reintubation: a Randomized Clinical Trial.

BackgroundLiberation and extubation are important for patients supported by mechanical ventilation. Extubation success is related to the duration of an intensive care unit (ICU) stay and mortality rate. High-flow nasal cannula (HFNC) oxygen therapy has physiological and clinical benefits in respiratory care. The present study compared clinical outcomes associated with HFNC and conventional oxygen therapy (COT) among patients at high risk for reintubation.MethodsA single-center randomized clinical trial was conducted between March 2018 and June 2019. Sixty adults admitted to the ICU and who were at high-risk of reintubation and met the inclusion criteria were enrolled in this study. “High risk” for reintubation was defined as having at least one of the following risk factors: age > 65 years, Acute Physiology and Chronic Health Evaluation II score > 12 points on extubation day, obesity, poor expectoration, airway patency problems, difficult or prolonged weaning, and more than one comorbidity. The primary outcome of interest was reintubation within 72 hours. Secondary outcomes included duration of ICU and hospital stay, mortality rate, and time to reintubation.ResultsOf 60 patients, 31 received HFNC and 29 received COT (mean age, 78 ± 7.8 vs. 76 ± 6.5 years, respectively). Reintubation rate within 72 hours did not differ between the groups (3 patients [9.7%] vs. 1 patient [3.4%], respectively). Reintubation time was shorter among patients who received COT than among patients who received HFNC (0.5 hour vs. 25 hours), but this difference was not statistically significant. Duration of ICU did not differ between the groups (14.7 ± 9.6 days vs. 13.8 ± 15.7 days, for HFNC and COT, respectively).ConclusionAmong patients at high risk for reintubation, compared with COT, HFNC did not reduce the risk of reintubation within 72 hours.

Initial Noninvasive Oxygenation Strategies in Subjects With De Novo Acute Hypoxemic Respiratory Failure.

De novo hypoxemic respiratory failure is defined as significant hypoxemia in the absence of chronic lung disease such as COPD, and excluding respiratory failure occurring in the immediate postoperative or postextubation period. We aimed to evaluate the efficacy of various oxygenation strategies including noninvasive ventilation (NIV), high-flow nasal cannula (HFNC), and conventional oxygen therapy in patients with de novo hypoxemic respiratory failure. We performed electronic database searches of PubMed, Cochrane Library, and Embase from inception to December 2018 to include randomized controlled trials that compared various oxygenation strategies in cases of de novo hypoxemic respiratory failure occurring in adult subjects without a preexisting chronic lung disease and excluding respiratory failure in the immediate postoperative or postextubation periods. We performed a Bayesian network meta-analysis to calculate odds ratio (OR) and Bayesian 95% credible intervals (CrI). 16 studies were included, involving 2,180 subjects with a mean age of 61 ± 17 y (66% were male; 46% of the included subjects were treated with conventional oxygen, 27.8% were treated with NIV, and 25.8% were treated with HFNC). Compared to conventional oxygen, NIV was associated with reduced intubation rates (OR 0.42, 95% CrI 0.26-0.62) but no significant reduction in short-term (OR 0.73, 95% CrI 0.47-1.02) or long-term mortality (OR 0.60, 95% CrI 0.29-1.06). There was no significant difference between NIV and HFNC or between HFNC and conventional oxygen regarding all outcomes. In a sensitivity analysis, the results remained consistent after exclusion of studies that included subjects with respiratory failure secondary to cardiogenic pulmonary edema. Among subjects with hypoxemic respiratory failure, NIV was associated with a significant reduction in intubation rates but not short- or long-term mortality when compared to conventional oxygen therapy. There was no significant difference between NIV and HFNC or between HFNC and conventional oxygen regarding all outcomes.

High-flow nasal cannula oxygen therapy versus conventional oxygen therapy in patients after planned extubation: a systematic review and meta-analysis

BackgroundThe effect of high-flow nasal cannula (HFNC) therapy in patients after planned extubation remains inconclusive. We aimed to perform a rigorous and comprehensive systematic meta-analysis to robustly quantify the benefits of HFNC for patients after planned extubation by investigating postextubation respiratory failure and other outcomes.MethodWe searched MEDLINE, EMBASE, Web of Science, and the Cochrane Library from inception to August 2018. Two researchers screened studies and collected the data independently. Randomized controlled trials (RCTs) and crossover studies were included. The main outcome was postextubation respiratory failure.ResultsTen studies (seven RCTs and three crossover studies; HFNC group: 856 patients; Conventional oxygen therapy (COT) group: 852 patients) were included. Compared with COT, HFNC may significantly reduce postextubation respiratory failure (RR, 0.61; 95% CI, 0.41, 0.92; z = 2.38; P = 0.02) and respiratory rates (standardized mean differences (SMD), − 0.70; 95% CI, − 1.16, − 0.25; z = 3.03; P = 0.002) and increase PaO2 (SMD, 0.30; 95% CI, 0.04, 0.56; z = 2.23; P = 0.03). There were no significant differences in reintubation rate, length of ICU and hospital stay, comfort score, PaCO2, mortality in ICU and hospital, and severe adverse events between HFNC and COT group.ConclusionsOur meta-analysis demonstrated that compared with COT, HFNC may significantly reduce postextubation respiratory failure and respiratory rates, increase PaO2, and be safely administered in patients after planned extubation. Further large-scale, multicenter studies are needed to confirm our results.

High-flow nasal cannula oxygen therapy versus conventional oxygen therapy in patients with acute respiratory failure: a systematic review and meta-analysis of randomized controlled trials

BackgroundAcute respiratory failure (ARF) is a common and life-threatening medical emergency in patients admitted to the hospital. Currently, there is a lack of large-scale evidence on the use of high-flow nasal cannulas (HFNC) in patients with ARF. In this systematic review and meta-analysis, we evaluated whether there were differences between HFNC therapy and conventional oxygen therapy (COT) for treating patients with ARF.MethodsThe EMBASE, Medline, and Wanfang databases and the Cochrane Library were searched. Two investigators independently collected the data and assessed the quality of each study. Randomized controlled trials that compared HFNC therapy with COT in patients with ARF were included. RevMan 5.3 was used to conduct the meta-analysis.ResultsFour studies that involved 703 patients with ARF were included, with 371 patients in the HFNC group and 332 patients in the COT group. In the overall estimates, there were no significant differences between the HFNC and COT groups in the rates of escalation of respiratory support (RR, 0.68; 95% CI, 0.37, 1.27; z = 1.20, P = 0.23), intubation (RR, 0.74; 95% CI, 0.55, 1.00; z = 1.95, P = 0.05), mortality (RR, 0.82; 95% CI, 0.36, 1.88; z = 0.47, P = 0.64), or ICU transfer (RR, 1.09; 95% CI, 0.57, 2.09; z = 0.26, P = 0.79) during ARF treatment. However, the subgroup analysis showed that HFNC therapy may decrease the rate of escalation of respiratory support (RR, 0.71; 95% CI, 0.53, 0.97; z = 2.15, P = 0.03) and the intubation rate (RR, 0.71; 95% CI, 0.53, 0.97; z = 2.15, P = 0.03) when ARF patients were treated with HFNC therapy for ≥24 h compared with COT.ConclusionsHFNC therapy was similar to COT in ARF patients. The subgroup analysis showed that HFNC therapy may decrease the rate of escalation of respiratory support and the intubation rate when ARF patients were treated with HFNC for ≥24 h compared with COT. Further high-quality, large-scale studies are needed to confirm our results.

The role of high-flow oxygen therapy in acute respiratory failure

Acute respiratory failure (ARF) represents one of the most common causes of intensive care unit admission and oxygen therapy remains the first-line therapy in the management of these patients. In recent years, high-flow oxygen via nasal cannula has been described as a useful alternative to conventional oxygen therapy in patients with ARF. High-flow oxygen via nasal cannula rapidly alleviates symptoms of ARF and improves oxygenation by several mechanisms, including dead space washout, reduction in oxygen dilution and inspiratory nasopharyngeal resistance, a moderate positive airway pressure effect that may generate alveolar recruitment and an overall greater tolerance and comfort with the interface and the heated and humidified inspired gases. However, the experience in adults is still limited and there are no clinical guidelines to establish recommendations for their use. This article aims to review the existing evidence on the use of high-flow oxygen via nasal cannula in adults with ARF and its possible applications, advantages and limitations.

Papel de la oxigenoterapia de alto flujo en la insuficiencia respiratoria aguda

Acute respiratory failure represents one of the most common causes of intensive care unit admission and oxygen therapy remains the first-line therapy in the management of these patients. In recent years, high-flow oxygen via nasal cannula has been described as a useful alternative to conventional oxygen therapy in patients with acute respiratory failure. High-flow oxygen via nasal cannula rapidly alleviates symptoms of acute respiratory failure and improves oxygenation by several mechanisms, including dead space washout, reduction in oxygen dilution and inspiratory nasopharyngeal resistance, a moderate positive airway pressure effect that may generate alveolar recruitment and an overall greater tolerance and comfort with the interface and the heated and humidified inspired gases. However, the experience in adults is still limited and there are no clinical guidelines to establish recommendations for their use. This article aims to review the existing evidence on the use of high-flow oxygen via nasal cannula in adults with acute respiratory failure and its possible applications, advantages and limitations.

Noninvasive Ventilation in Acute Cardiogenic Pulmonary Edema

In patients with acute cardiogenic pulmonary edema noninvasive ventilation may reduce intubation rate, but the impact on mortality and the superiority of one technique over another have not been clearly established. To systematically review and quantitatively synthesize the short-term effect of noninvasive ventilation on major clinical outcomes. MEDLINE and EMBASE (from inception to October 2005) and Cochrane databases (library issue 4, 2005) were searched to identify relevant randomized controlled trials and systematic reviews published from January 1, 1988, to October 31, 2005. Included trials were all parallel studies comparing noninvasive ventilation to conventional oxygen therapy in patients with acute pulmonary edema. Comparisons of different techniques, either continuous positive airway pressure (CPAP) or bilevel noninvasive pressure support ventilation (NIPSV), were also included. Fifteen trials were selected. Overall, noninvasive ventilation significantly reduced the mortality rate by nearly 45% compared with conventional therapy (risk ratio [RR], 0.55; 95% confidence interval [CI], 0.40-0.78; P = .72 for heterogeneity). The results were significant for CPAP (RR, 0.53; 95% CI, 0.35-0.81; P = .44 for heterogeneity) but not for NIPSV (RR, 0.60; 95% CI, 0.34-1.05; P = .76 for heterogeneity), although there were fewer studies in the latter. Both modalities showed a significant decrease in the "need to intubate" rate compared with conventional therapy: CPAP (RR, 0.40; 95% CI, 0.27-0.58; P = .21 for heterogeneity), NIPSV (RR, 0.48; 95% CI, 0.30-0.76; P = .24 for heterogeneity), and together (RR, 0.43; 95% CI, 0.32-0.57; P = .20 for heterogeneity). There were no differences in intubation or mortality rates in the analysis of studies comparing the 2 techniques. Noninvasive ventilation reduces the need for intubation and mortality in patients with acute cardiogenic pulmonary edema. Although the level of evidence is higher for CPAP, there are no significant differences in clinical outcomes when comparing CPAP vs NIPSV.