应用无创通气作为急性呼吸衰竭患者撤机方法的研究

目的评价接受机械通气治疗的急性呼吸衰竭(ARF)患者应用无创通气(NIV)撤机的临床效果。方法58例ARF患者经气管插管机械通气治疗48h后病情好转,尚未完全满足撤机条件时随机分为两组,NIV组:拔管立即给予NIV作为撤机方法;有创压力支持通气(IPSV)组:继续经人工气道给予PSV实施撤机。观察比较两组患者动脉血气变化、并发症发生率、机械通气时间和住院时间、再插管率和病死率。结果NIV组有创通气时间显著短于IPSV组(P<0.05),两组总的通气支持时间相似。NIV组呼吸机相关性肺炎(VAP)的发生率显著低于IPSV组(P<0.05),住院时间显著短于IPSV组(P<0.05)。两组再插管率和病死率相似。结论NIV用于接受机械通气的ARF患者撤机可缩短有创通气时间和住院时间,降低VAP的发生率。     

Outcomes of morbidly obese patients requiring mechanical ventilation for acute respiratory failure

OBJECTIVE: To examine the outcomes of morbidly obese patients with acute respiratory failure treated with mechanical ventilation. DESIGN: Retrospective study. SETTING: A 14-bed medical intensive care unit in an 800-bed university-based hospital. PATIENTS: A total of 50 morbidly obese subjects with acute respiratory failure requiring ventilatory assistance. INTERVENTIONS: None. MEASUREMENTS: Arterial blood gas measurements, intubation rate, days of mechanical ventilation, intensive care unit length of stay, hospital length of stay, and mortality. RESULTS: From January 1997 to December 2004, 50 morbidly obese patients with acute respiratory failure were treated with mechanical ventilation. Invasive mechanical ventilation was implemented in 17 patients with a mean body mass index of 53.2 +/- 12.2 kg/m2. A total of 33 patients were treated with noninvasive ventilation (NIV), of which 21 avoided intubation (NIV success) and 12 required intubation (NIV failure). Mean body mass index for the NIV success group was significantly less than for the NIV failure group (46.9 +/- 8.9 and 62.5 +/- 16.1 kg/m2, respectively, p = .001). Acute Physiology and Chronic Health Evaluation II scores were similar for patients treated with invasive and noninvasive ventilation. Significant improvements in pH and Paco2 were noted for the invasive mechanical ventilation and NIV success groups. No improvements in gas exchange were noted in the NIV failure group. Of patients treated with NIV, 36% required intubation. Hospital mortality for the invasive ventilation and NIV failure groups was increased. CONCLUSION: The type of ventilatory assistance may influence clinical outcomes in morbidly obese patients with acute respiratory failure.     

Noninvasive ventilation in the event of acute respiratory failure in patients with idiopathic pulmonary fibrosis

Background

Some patients with idiopathic pulmonary fibrosis (IPF) develop severe acute respiratory failure (ARF) requiring admission to an intensive care unit (ICU) and ventilatory support. A limited number of observational studies have reported that noninvasive ventilation (NIV) can be an effective treatment to support breathing and to prevent use of invasive mechanical ventilation in these patients. This study aimed to retrospectively investigate the clinical status and outcomes in IPF patients receiving NIV for ARF and to identify those clinical and laboratory characteristics, which could be considered risk factors for its failure.

Methods

This is a retrospective analysis of short-term outcomes in 18 IPF patients being administered NIV for ARF. This study was conducted in a 4-bed respiratory ICU (RICU) in a university hospital. Eighteen IPF patients who were administered NIV between January 1, 2005, and April 30, 2013, were included. The outcome measures are the need for endotracheal intubation despite NIV treatment and mortality rate during their RICU stay. The length of the patients' stay in the RICU and their survival rate following RICU admission were also evaluated.

Results

Noninvasive ventilation was successful in 8 patients and unsuccessful in 10 who required endotracheal intubation. All the patients in the NIV failure group died within 20.2 ± 15.3 days of intubation. The patients in the NIV success group spent fewer days in the RICU (11.6 ± 4.5 vs 24.6 ± 13.7; P = .0146). The median survival time was significantly shorter for the patients in the NIV failure with respect to the success group (18.0 [95% confidence interval {CI}, 9.0-25.0] vs 90.0 [95% CI, 65.0-305.0] days; P < .0001); the survival rate at 90 days was, likewise, lower in the NIV failure group (0% vs 34% ± 19.5%). At admission, the patients in the failure group had significantly higher respiratory rate values (36.9 ± 7.8 vs 30.5 ± 3.3 breaths/min; P = .036), plasma N-terminal fragment of the prohormone of B-type natriuretic peptide (NT-proBNP) levels (4528.8 ± 4012.8 vs 634.6 ± 808.0 pg/mL; P = .023) and serum C-reactive protein values (72.0 ± 50.0 vs 20.7 ± 24.0 μg/mL; P = .0289) with respect to those in the success group. Noninvasive ventilation failure was correlated to the plasma NT-proBNP levels at RICU admission (P = .0326) with an odds ratio of 12.2 (95% CI, 1.2 to infinity) in the patients with abnormally high values (>900 pg/mL).

Conclusions

The outcome of IPF patients who were administered NIV was quite poor. The use of NIV was, nevertheless, found to be associated with clinical benefits in selected IPF patients, preventing the need for intubation and reducing the rate of complications/death. Elevated plasma NT-proBNP levels at the time of ICU admission is a simple clinical marker for poor NIV outcome.     

Noninvasive ventilation after early extubation in patients recovering from hypoxemic acute respiratory failure: a single-centre feasibility study

Purpose

The use of noninvasive ventilation (NIV) to facilitate discontinuation of mechanical ventilation in patients with acute hypoxemic respiratory failure (hypoxemic ARF) has never been explored. This pilot study aims to assess the feasibility of early extubation followed by immediate NIV, compared conventional weaning, in patients with resolving hypoxemic ARF.

Methods

Twenty consecutive hypoxemic patients were randomly assigned to receive either conventional weaning or NIV. The changes in arterial blood gases and respiratory rate were compared between the two groups at 1, 12, 24 and 48?h. Differences in the rate of extubation failure, ICU and hospital mortality, number of invasive-ventilation-free-days at day 28, septic complications, number of tracheotomies, days and rates of continuous intravenous sedation, and ICU length of stay were also determined.

Results

No patient interrupted the study protocol. Arterial blood gases were similar during invasive mechanical ventilation, 1?h after NIV application following extubation, and after 12, 24 and 48?h. Respiratory rate was higher after 1?h in the NIV group, but no different after 12, 24 and 48?h. The number of invasive-ventilation-free-days at day 28 was 20?±?8 (min?=?0, max?=?25) days in the treatment group and 10?±?9 (min?=?0, max?=?25) days in the control group (p?=?0.014). The rate of extubation failure, ICU and hospital mortality, tracheotomies, septic complications, days and rates of continuous sedation, and ICU length of stay were not significantly different between the two groups.

Conclusions

In a highly experienced centre NIV may be used to facilitate discontinuation of mechanical ventilation in selected patients with resolving hypoxemic ARF.     

Non-invasive pressure support ventilation in patients with acute respiratory failure after bilateral lung transplantation

OBJECTIVE: To evaluate non-invasive ventilation (NIV) prospectively in a group of patients developing acute respiratory failure (ARF) after bilateral lung transplantation (BLT). SETTING: General intensive care unit (ICU) of Rome "La Sapienza" University. PATIENTS: Twenty-one patients (18 with cystic fibrosis) undergoing BLT. RESULTS: All consecutive patients developing ARF (according to predefined criteria) and requiring ventilatory support, received non-invasive pressure support ventilation through a face-mask (PEEP 5 cmH2O, PSV 14+/-2 cmH2O) for a mean period of 5+/-4 days. Eighteen out of 21 patients avoided intubation and were discharged from the ICU; 3 patients required intubation: 1 of them survived while 2 developed septic shock and died. CONCLUSIONS: NIV administration was well tolerated and avoided intubation in the large majority of patients (86%); in NIV responders the rate of complications was low and ICU mortality nil. NIV should be considered as an interesting alternative to conventional ventilation in patients who require ventilatory support after BLT.     

La ventilation non-invasive au decours de l'intubation

The significant advance and clinical benefit of non invasive ventilation (NIV) in the initial management of acute respiratory failure (ARF) led to use this technique as a non invasive ventilatory strategy following intubation (postintubation NIV). In this condition, NIV can be applied in two different indications with potential different results: either to facilitate weaning from endotracheal mechanical ventilation (ETMV) and reduce the duration of intubation or to avoid reintubation in case of ARF occurring within 24 to 72 hours after extubation. Current data show a clinical benefit of NIV, as a strategy of difficult weaning, on the duration of intubation, weaning success, length of stay, ETMV complications as well as mortality, mainly in chronic obstructive pulmonary disease patients. In contrast, the more controversial results observed with NIV applied to the postextubation ARF should lead the clinician to be cautious in its daily clinical practice. In all cases, the postintubation NIV can only be considered with a sufficiently experienced team in the technique and should not unnecessarily delay the reintubation time. Further studies will be needed to enhance the clinical and economical challenge of such a non invasive ventilatory strategy applied to the postintubation period.     

Safety and efficacy of noninvasive ventilation in patients with blunt chest trauma: a systematic review

Introduction

This systematic review looks at the use of noninvasive ventilation (NIV), inclusive of noninvasive positive pressure ventilation (NPPV) and continuous positive pressure ventilation (CPAP), in patients with chest trauma to determine its safety and clinical efficacy in patients with blunt chest trauma who are at high risk of acute lung injury (ALI) and respiratory failure.

Methods

We searched the MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL) databases. Pairs of reviewers abstracted relevant clinical data and assessed the methodological quality of randomized controlled trials (RCTs) using the Cochrane domain and observational studies using the Newcastle-Ottawa Scale.

Results

Nine studies were included (three RCTs, two retrospective cohort studies and four observational studies without a comparison group). There was significant heterogeneity among the included studies regarding the severity of injuries, degree of hypoxemia and timing of enrollment. One RCT of moderate quality assessed the use of NPPV early in the disease process before the development of respiratory distress. All others evaluated the use of NPPV and CPAP in patients with blunt chest trauma after the development of respiratory distress. Overall, up to 18% of patients enrolled in the NIV group needed intubation. The duration of NIV use was highly variable, but NIV use itself was not associated with significant morbidity or mortality. Four low-quality observational studies compared NIV to invasive mechanical ventilation in patients with respiratory distress and showed decreased ICU stay (5.3 to 16 days vs 9.5 to 15 days), complications (0% to 18% vs 38% to 49%) and mortality (0% to 9% vs 6% to 50%) in the NIV group.

Conclusions

Early use of NIV in appropriately identified patients with chest trauma and without respiratory distress may prevent intubation and decrease complications and ICU length of stay. Use of NIV to prevent intubation in patients with chest trauma who have ALI associated with respiratory distress remains controversial because of the lack of good-quality data.     

Noninvasive ventilation for treating acute respiratory failure in AIDS patients with Pneumocystis carinii pneumonia

OBJECTIVE: To compare noninvasive positive pressure ventilation (NPPV) vs. invasive mechanical ventilation in AIDS patients with Pneumocystis carinii pneumonia (PCP)-related acute respiratory failure (ARF). DESIGN: A single-center, prospective, case-control trial. SETTING: An ICU of a private tertiary hospital specialized in infectious disease. PATIENTS: Forty-eight AIDS patients with severe PCP-related ARF needing mechanical ventilation.Interventions: Twenty-four patients treated with NPPV by a facial mask strictly matched with 24 patients treated with invasive ventilation by endotracheal intubation. RESULTS: Use of NPPV avoided intubation in 67% of patients, and avoidance of intubation was associated with improved survival (100% vs. 38%; P=0.003). NPPV-treated patients required fewer invasive devices ( P<0.001) and had a lower incidence of pneumothoraces (8.3% vs. 37.5%; P=0.039). The NPPV-treated group required a nurse workload similar to that of the conventional ventilation group, but this group had a shorter duration of stay in the ICU ( P=0.013). The NPPV-treated group had a lower mortality in the ICU, the hospital and within 2 months of study entry. Differences in mortality between the two groups disappeared after 6 months. CONCLUSIONS: The findings of this study seem to provide further support for applying NPPV in AIDS patients with severe PCP-related ARF as a first-line therapeutic choice, but randomized controlled trials are required to confirm our results.     

有创与无创序贯性机械通气治疗慢性阻塞性肺疾病所致呼吸衰竭的临床研究

目的探讨有创与无创序贯性机械通气在慢性阻塞性肺疾病（COPD）所致呼吸衰竭患者救治中的方法与疗效。方法对41例COPD呼吸衰竭患者进行气管插管并施行机械通气,出现HC窗后,随机分为序贯治疗组（21例）和对照组（20例）。序贯组治疗方法：出现PIC窗后,立即拔出气管插管,改用口鼻面罩双水平气道正压通气（BiPAP）。对照组治疗方法：出现HC窗后,继续按常规有创机械通气方法治疗,按临床常用压力支持通气（PSV）模式脱机。两组同时进行监护,观察两组患者VAP发生例数、有创通气时间、总机械通气时间、ICU监护时间、住院时间、住院费用和院内死亡例数。结果序贯组与对照组比较,VAP发生少,有创通气时间、总通气时间、ICU监护时间及住院时间短,住院费用减少（P〈0．05）,差异有统计学意义。结论在“肺部感染控制窗”指导下的有创一无创序贯性脱机治疗方法,可以明显降低VAP发病率,缩短机械通气,ICU和总住院时间,提高疗效,降低治疗费用,是具有一定临床实用价值的有效脱机方案。     

Noninvasive ventilation in hypercapnic acute respiratory failure due to chronic obstructive pulmonary disease vs. other conditions: effectiveness and predictors of failure

Objective This study compared the effectiveness of noninvasive ventilation (NIV) and the risk factors for NIV failure in hypercapnic acute respiratory failure (ARF) due to chronic obstructive pulmonary disease (COPD) vs. non-COPD conditions.Design and setting Prospective cohort study in the medical intensive care unit of a university hospital.Patients and participants 111 patients with hypercapnic ARF, 43 of whom had COPD exacerbations and 68 other conditions. Baseline characteristics of the two groups were similar.Measurements and results The risk of NIV failure, defined as the need for endotracheal intubation, was significantly lower in COPD than in other conditions (19% vs. 47%). High APACHE II score was an independent predictor of NIV failure in COPD (OR 5.38 per 5 points). The presence of pneumonia (OR 5.63), high APACHE II score (OR 2.59 per 5 points), rapid heart rate (OR 1.22 per 5 beats/min), and high PaCO₂ 1 h after NIV (OR 1.22 per 5 mmHg) were independent predictors of NIV failure in the non-COPD group. Failure of NIV independently predicted mortality (OR 10.53).Conclusions Noninvasive ventilation was more effective in preventing endotracheal intubation in hypercapnic ARF due to COPD than non-COPD conditions. High APACHE II score predicted NIV failure in both groups. Noninvasive ventilation was least effective in patients with hypercapnic ARF due to pneumonia.This revised version was published online in March 2005. In the abstract all occurrences of 95% CI were deleted, and in the main text some orthographical corrections were made.     

Noninvasive mechanical ventilation as a palliative treatment of acute respiratory failure in patients with end-stage solid cancer

Noninvasive ventilation (NIV) is widely used in the treatment of acute respiratory failure (ARF), but not in patients with end-stage solid cancer in whom any form of mechanical ventilation tends to be avoided. In a prospective study, we investigated the use of NIV in 23 patients with solid malignancies receiving palliative care and who were affected by severe hypoxic or hypercapnic ARF. The most frequent causes of ARF were exacerbations of pre-existing pulmonary diseases and pneumonia. After one hour, NIV significantly improved PaO2/FiO2 (from 154+/-48 to 187+/-55) and the Borg dyspnoea score (from 5.5+/-1.2 to 2.3+/-0.3). NIV also improved pH, but only in the subset of hypercapnic patients. Thirteen of 23 (57%) patients were successfully ventilated and discharged alive, while 10/23 patients (43%) met the criteria for intubation or died after an initial trial of NIV. Only two of these patients accepted invasive ventilation. The mortality rate in this subgroup was 9/10 (90%). A higher Simplified Acute Physiology Score (SAPS II) and a lower PaO2/FiO2 on admission were associated with a lower probability of survival. Patients with ARF and end-stage solid malignancies have an overall ICU and 1-year mortality rate of 39% and 87%, respectively, but despite this, a consistent subset of patients may still be successfully treated with NIV, if the cause of ARF is reversible.     

Non-invasive ventilation as a strategy for weaning from invasive mechanical ventilation: a systematic review and Bayesian meta-analysis

Purpose

A systematic review and meta-analysis was conducted to answer the question ‘In adults with respiratory failure requiring invasive ventilation for more than 24 h, does a weaning strategy with early extubation to non-invasive ventilation (NIV) compared to invasive ventilation weaning reduce all-cause hospital mortality?’

Methods

We included randomised and quasi-randomised controlled trials that evaluated the use of non-invasive ventilation, compared to invasive ventilation, as a weaning strategy in adults mechanically ventilated for at least 24 h. The EMBASE, MEDLINE and Cochrane Central Register of Controlled Trials (CENTRAL) bibliographic databases were searched from inception to February 2018. Bayesian hierarchical models were used to perform the meta-analysis. The primary outcome was mortality at hospital discharge. Secondary outcomes included mortality (30, 60, 90 and 180 days), quality of life, duration of invasive ventilation, weaning failure, length of stay [intensive care unit (ICU) and hospital] and adverse events.

Results

Twenty-five relevant studies involving 1609 patients were included in the quantitative analysis. Studies had moderate to high risk of bias due to risk of performance and detection bias. Mortality at hospital discharge was lower in the NIV weaning group compared to the invasive weaning group [pooled odds ratio (OR) 0.58, 95% highest density interval (HDI) 0.29–0.89]. Subgroup analyses showed lower pooled mortality at hospital discharge rates in NIV weaning than those in the control group in chronic obstructive pulmonary disease (COPD) patients (pooled OR 0.43, 95% HDI 0.13–0.81) and the effect is less certain in the mixed ICU population (pooled OR 0.88, 95% HDI 0.25–1.48). NIV weaning reduced the duration of invasive ventilation in patients [standardised mean difference (SMD) ??1.34, 95% HDI ??1.92 to ??0.77] and ICU length of stay (SMD ??0.70, 95% HDI ??0.94 to ??0.46). Reported rates of ventilator associated pneumonia (VAP) were lower in the NIV group. NIV weaning did not reduce overall hospital length of stay or long-term mortality. There were insufficient data to compare other adverse events and health-related quality of life.

Conclusions

The use of NIV in weaning from mechanical ventilation decreases hospital mortality, the incidence of VAP and ICU length of stay. NIV as a weaning strategy appears to be most beneficial in patients with COPD.

     

La ventilation non invasive au cours des insuffisances respiratoires aiguës hypoxémiques

Treatment of acute respiratory failure (ARF) generally requires mechanical ventilation via endotracheal intubation. This technique, however, involves numerous side effects. Noninvasive ventilation (NIV) reduces the need for endotracheal intubation and the related morbidity in patients with acute exacerbation of chronic obstructive pulmonary diseases. In patients with previously healthy lungs, controlled studies strongly suggest that NIV may play a role in the treatment of hypoxemic ARF. It reduces the number of patients to be intubated as well as infectious side effects. Noninvasive ventilation is likely to treat patients with rapidly reversible acute cardiogenic pulmonary edema. NIV may be of benefit in patients with pneumonia of mild severity. In the treatment of adult respiratory distress syndrome, NIV should be limited to the least severe patients. The success of NIV seems associated with five physiopathological conditions: hypercapnia, sustained gas exchange improvement, rapidly reversible cause of ARF, patients' cooperation.     

Noninvasive ventilation for the treatment of acute respiratory failure in patients with hematologic malignancies: a pilot study

Objective: To evaluate treatment with noninvasive ventilation (NIV) by nasal mask as an alternative to endotracheal intubation and conventional mechanical ventilation in patients with hematologic malignancies complicated by acute respiratory failure to decrease the risk of hemorrhagic complications and increase clinical tolerance. Design: Prospective clinical study. Setting: Hematologic and general intensive care unit (ICU), University of Rome “La Sapienza”. Patients: 16 consecutive patients with acute respiratory failure complicating hematologic malignancies. Interventions: NIV was delivered via nasal mask by means of a BiPAP ventilator (Respironics, USA); we evaluated the effects on blood gases, respiratory rate, and hemodynamics along with tolerance, complications, and outcome. Measurements and results: 15 of the 16 patients showed a significant improvement in blood gases and respiratory rate within the first 24 h of treatment. Arterial oxygen tension (PaO₂), PaO₂/FIO₂ (fractional inspired oxygen) ratio, and arterial oxygen saturation significantly improved after 1 h of treatment (43 ± 10 vs 88 ± 37 mmHg; 87 ± 22 vs 175 ± 64; 81 ± 9 vs 95 ± 4 %, respectively) and continued to improve in the following 24 h (p < 0.01). Five patients died in the ICU following complications independent of the respiratory failure, while 11 were discharged from the ICU in stable condition after a mean stay of 4.3 ± 2.4 days and were discharged in good condition from the hospital. Conclusions: NIV by nasal mask proved to be feasible and appropriate for the treatment of respiratory failure in hematologic patients who were at high risk of intubation – related complications. Received: 21 April 1998 Accepted: 18 September 1998     

Noninvasive ventilation immediately after extubation improves weaning outcome after acute respiratory failure: a randomized controlled trial

Introduction

Noninvasive ventilation (NIV), as a weaning-facilitating strategy in predominantly chronic obstructive pulmonary disease (COPD) mechanically ventilated patients, is associated with reduced ventilator-associated pneumonia, total duration of mechanical ventilation, length of intensive care unit (ICU) and hospital stay, and mortality. However, this benefit after planned extubation in patients with acute respiratory failure of various etiologies remains to be elucidated. The aim of this study was to determine the efficacy of NIV applied immediately after planned extubation in contrast to oxygen mask (OM) in patients with acute respiratory failure (ARF).

Methods

A randomized, prospective, controlled, unblinded clinical study in a single center of a 24-bed adult general ICU in a university hospital was carried out in a 12-month period. Included patients met extubation criteria with at least 72 hours of mechanical ventilation due to acute respiratory failure, after following the ICU weaning protocol. Patients were randomized immediately before elective extubation, being randomly allocated to one of the study groups: NIV or OM. We compared both groups regarding gas exchange 15 minutes, 2 hours, and 24 hours after extubation, reintubation rate after 48 hours, duration of mechanical ventilation, ICU length of stay, and hospital mortality.

Results

Forty patients were randomized to receive NIV (20 patients) or OM (20 patients) after the following extubation criteria were met: pressure support (PSV) of 7 cm H₂O, positive end-expiratory pressure (PEEP) of 5 cm H₂O, oxygen inspiratory fraction (FiO₂) ≤ 40%, arterial oxygen saturation (SaO₂) ≥ 90%, and ratio of respiratory rate and tidal volume in liters (f/TV) < 105. Comparing the 20 patients (NIV) with the 18 patients (OM) that finished the study 48 hours after extubation, the rate of reintubation in NIV group was 5% and 39% in OM group (P = 0.016). Relative risk for reintubation was 0.13 (CI = 0.017 to 0.946). Absolute risk reduction for reintubation showed a decrease of 33.9%, and analysis of the number needed to treat was three. No difference was found in the length of ICU stay (P = 0.681). Hospital mortality was zero in NIV group and 22.2% in OM group (P = 0.041).

Conclusions

In this study population, NIV prevented 48 hours reintubation if applied immediately after elective extubation in patients with more than 3 days of ARF when compared with the OM group.

Trial Registration number

ISRCTN: 41524441.     

Non-invasive mechanical ventilation in severe chronic obstructive lung disease and acute respiratory failure: short-and long-term prognosis

Objective To evaluate the short-and long-term prognosis of patients with chronic obstructive lung disease (COLD) who had noninvasive mechanical ventilation (NMV) for acute respiratory failure (ARF).Design Retrospective study.Setting Two respiratory intermediate intensive care units.Patients Two groups of patients suffering from COLD and an ARF episode requiring mechanical ventilation. Group 1 (30 patients) was given NMV using face masks (aged 64±9 years; pH=7.28±0.05; PaCO₂=83±18 mmHg; PaO₂/FIO₂=141±61). Group 2 (27 patients) was composed of control patients (aged=65±8 years; pH=7.26±0.05; PaCO₂=75±17 mmHg; PaO₂/FIO₂=167±41) given MV using endotracheal intubation (EI) when clinical and functional conditions had further deteriorated because the medical therapy failed and NMV was not available at the time. Causes of ARF were in group 1 and 2 respectively: pneumonia in 8(27%) and 11(41%), acute exacerbation of COLD in 19 (63%) and 14 (52%) and pulmonary embolism in 3 (10%) and 2 (7%) patients.Measurements and results Success rate, mortality during stay in ICU (at 3 months and at 1 year), and the need for rehospitalization during the year following ARF were measured in this study. Group 1 showed a success rate of 74%, only 8/30 patients needing EI and conventional MV. In group 2, the weaning success was 74% (20/27 patients). The mortality for group 1 was 20% in IICU, 23% at 3 months and 30% at 1 year; and 26% for group 2 in ICU, 48% at 3 months and 63% at 1 year. Within each group 1-year mortality was greater (p<0.01) in patients with pneumonia. The number of new ICU admissions during the follow-up at 1 year was 0.12 versus 0.30 in groups 1 and 2 respectivelyp<0.05).Conclusion For patients suffering from COLD who have undergone ARF, avoiding EI by early treatment with NMV is associated with better survival in comparison to patients bound to invasive MV. Pneumonia as a cause of ARF may worsen the prognosis in both groups of patients.     

Noninvasive ventilation

Non invasive ventilation is defined as mechanical ventilation without the use of endotracheal intubation and has been increasingly established within intensive care units during the last decades. Negative pressure ventilation and non invasive positive pressure ventilation have been successfully applied, first in chronic respiratory failure (CRF) due to various causes and later in acute respiratory failure (ARF). In this review ventilation modes, indications, contraindications and side effects of non invasive ventilation are analysed and the impact of non invasive ventilation on the physiology, pathophysiology and outcome of CRF and ARF, and possible applications in CRF (restrictive chest and pulmonary diseases, neuromuscular diseases and COPD) and ARF are discussed. It is concluded that non invasive ventilation should be included in the routine management of respiratory failure at all intensive care units.     

Benefits and risks of success or failure of noninvasive ventilation

Objective Noninvasive ventilation (NIV) fails more frequently for de novo acute respiratory failure (de novo) than for cardiogenic pulmonary edema (CPE) or acute-on-chronic respiratory failure (AOC). The impact of NIV failure and success was compared between de novo and CPE or AOC after adjustment for disease severity.Settings Patients requiring ventilatory support were enrolled in a prospective survey in 70 French ICUs. Of 1076 patients requiring ventilatory support, 524 were eligible, including 299 de novo (NIV use, 30%) and 225 CPE-AOC (NIV use, 55%).Design and analysis Independent risk factors associated with mortality and length of stay were identified by logistic regression analysis. The adjusted outcome of NIV success or failure was compared to that with endotracheal intubation without NIV.Results NIV success was independently associated with survival in both de novo, adjusted OR 0.05 (95% CI 0.01–0.42), and CPE-AOC OR 0.03 (CI 0.01–0.24). NIV failure was associated with ICU mortality in the de novo group (OR 3.24, CI 1.61–6.53) but not in the CPE-AOC group. Nosocomial pneumonia was less common in patients successful with NIV. NIV failure was associated with a longer ICU stay in CPE-AOC only. The overall use of NIV was independently associated with a better outcome only in CPE-AOC patients (OR 0.33, CI 0.15–0.73).Conclusion The effect of NIV differs between de novo and CPE-AOC patients because NIV failure is associated with increased mortality for de novo patients. This finding should raise a note of caution when applying NIV in this indication.This study was performed for the SRLF Task Force Mechanical Ventilation.     

Non-invasive mechanical ventilation in hematology patients: let's agree on several things first

Acute respiratory failure is a dreaded and life-threatening event that represents the main reason for ICU admission. Respiratory events occur in up to 50% of hematology patients, including one-half of those admitted to the ICU. Mortality from acute respiratory failure in hematology patients depends on the patient''s general status, acute respiratory failure etiology, need for mechanical ventilation and associated organ dysfunction. Non-invasive mechanical ventilation is clearly beneficial for chronic obstructive pulmonary disease exacerbation and cardiogenic pulmonary edema. These benefits are based mainly on the avoidance of invasive mechanical ventilation complications. Non-invasive mechanical has also been recommended in hematology patients with acute respiratory failure but its real benefits remain unclear in these settings. There is growing concern about the safety of non-invasive mechanical ventilation to treat hypoxemic acute respiratory failure overall, but also in hematology patients. Prophylactic non-invasive mechanical ventilation in patients with acute respiratory failure but not respiratory distress seems to be effective in hematology patients with a reduced rate of intubation. However, curative non-invasive mechanical ventilation should be restricted to those patients with isolated respiratory failure, with fast improvement of respiratory distress under non-invasive mechanical ventilation, and with rapid switch to intubation to avoid deleterious delays in optimal invasive mechanical ventilation.In a previous issue of Critical Care, Molina and colleagues provide the results of a large multicenter Spanish observational cohort study of hematology patients with acute respiratory failure (ARF) [1]. Their main findings are that non-invasive mechanical ventilation (NIV) failure is an independent risk factor for ICU mortality. Indeed, NIV patients exhibited higher mortality rates compared with patients who were intubated early. Not surprisingly, cardiogenic pulmonary edema was associated with reduced proportion of NIV failure.The observational design does not actually allow any firm conclusion about NIV efficacy in hematology patients. The poorer prognosis associated with NIV failure could simply result from patient selection, clinicians being less keen to intubate patients without lifespan-expanding therapy or those who were older or sickest. Late intubation would thus only be a surrogate marker of poor prognosis. Nevertheless, this study is along the line of other studies in the literature that show early intubation to be associated with lower mortality [2,3]. In hematology patients with hypoxemic ARF, therefore, the questionable benefit from NIV supports the dilemma of intubation timing faced by clinicians managing these patients.ARF occurs in up to 50% of hematology patients and is the leading reason for ICU admission in this population. Despite significant improvement in the last years [4,5], ARF still carries a high mortality rate of 50% overall, with even higher rates in patients needing mechanical ventilation [4,6,7]. The high incidence of cancer together with the use of a highly intensive curative regimen will increase the number of patients at risk of respiratory complications, and physicians will be asked to manage these patients more and more.NIV is now recognized as the first-line therapy for patients with ARF due to chronic obstructive pulmonary disease exacerbation or cardiogenic pulmonary edema [8]. The clear benefit of NIV in these patients relies on the reduced rate of complications from invasive mechanical ventilation. NIV has also been recommended for hypoxemic ARF in immunocompromised patients [9]. In the subgroup of hematology patients, invasive mechanical ventilation has been associated with the worse prognosis of ARF [4,6,7] and NIV may therefore be particularly beneficial to these patients. However, published studies have inconsistently found a benefit from NIV in these patients [1,4,6,10-12].Several factors may explain these discordant results. First, studies did not control the timing of NIV implementation and evaluated together prophylactic NIV (in patients with hypoxemia but no respiratory distress) and curative NIV (in patients with established respiratory distress) [10,13]. Second, the unit where NIV was performed - the hematology ward or the ICU - differed between studies [11,12]. Early ICU admission and the opportunity for tight monitoring probably positively impacted the results, whereas delayed ICU admission for patients treated in the hematology ward may have worsened prognosis with delayed intubation and treatment of associated organ failures [13]. Third, studies included patients with ARF from various etiologies, some of which may better respond to NIV. Finally, studies did not take into account associated organ dysfunctions that may have hampered NIV efficacy.The overall lack of actually proven benefit from NIV in hypoxemic ARF of hematology patients therefore raises safety concerns for its use in patients who may benefit from early intubation and mechanical ventilation [14]. The recent advances in life-sustaining therapies and the better outcome of hematology patients admitted to the ICU in the last years strengthen these concerns [4,5].Taken together, studies evaluating NIV in hematology patients highlight the deleterious effects of NIV failure and late intubation, as does the study by Molina and colleagues [1,10,13]. Improving NIV results in these patients will probably derive from tailor-made management based on the lessons we have learned from these studies (Figure ​(Figure11 and Table ​Table1).1). In our belief, this relies on the three following points: improved patient selection, careful identification of ARF etiology [7], and early assessment of NIV efficacy. Available evidence supports the use of prophylactic NIV performed in the ICU in hematology patients [10]. These benefits may result from improved oxygenation and reduced work of breathing that alleviate respiratory load. Prophylactic NIV may also help to secure diagnostic procedures such as fiberoptic bronchoscopy and bronchoalveolar lavage [15]. In opposition, we believe the reason why NIV may be effective for hypoxemic ARF in hematology patients and not in other settings is highly questionable. We therefore recommend the cautious use of curative NIV only in patients with isolated ARF and with an early assessment of its efficacy. Curative NIV should be discouraged in patients with an associated extra-respiratory organ failure and should be contraindicated in those with two or more extra-respiratory failures.Open in a separate windowFigure 1Propositions for the use of non-invasive mechanical ventilation in hematology patients with acute respiratory failure. ARF, acute respiratory failure; NIV, non-invasive mechanical ventilation; RRT, renal replacement therapy.

Table 1

Situations in which NIV should be encouraged or avoided in hematology patients

Noninvasive and invasive ventilation in acute respiratory failure associated with bronchiectasis

Purpose  

To describe the outcomes of patients with bronchiectasis and acute respiratory failure (ARF) treated with noninvasive ventilation (NIV) and invasive mechanical ventilation (IMV) after a failure of conservative measures, and to identify the predictors of hospital mortality and NIV failure.