Physiological response to pressure support ventilation delivered before and after extubation in patients not capable of totally spontaneous autonomous breathing

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

Dyspnoea in acutely ill mechanically ventilated adult patients: an ERS/ESICM statement

This statement outlines a review of the literature and current practice concerning the prevalence, clinical significance, diagnosis and management of dyspnoea in critically ill, mechanically ventilated adult patients. It covers the definition, pathophysiology, epidemiology, short- and middle-term impact, detection and quantification, and prevention and treatment of dyspnoea. It represents a collaboration of the European Respiratory Society and the European Society of Intensive Care Medicine. Dyspnoea ranks among the most distressing experiences that human beings can endure. Approximately 40% of patients undergoing invasive mechanical ventilation in the intensive care unit (ICU) report dyspnoea, with an average intensity of 45 mm on a visual analogue scale from 0 to 100 mm. Although it shares many similarities with pain, dyspnoea can be far worse than pain in that it summons a primal fear response. As such, it merits universal and specific consideration. Dyspnoea must be identified, prevented and relieved in every patient. In the ICU, mechanically ventilated patients are at high risk of experiencing breathing difficulties because of their physiological status and, in some instances, because of mechanical ventilation itself. At the same time, mechanically ventilated patients have barriers to signalling their distress. Addressing this major clinical challenge mandates teaching and training, and involves ICU caregivers and patients. This is even more important because, as opposed to pain which has become a universal healthcare concern, very little attention has been paid to the identification and management of respiratory suffering in mechanically ventilated ICU patients.

Dyspnoea in acutely ill mechanically ventilated adult patients: an ERS/ESICM statement

This statement outlines a review of the literature and current practice concerning the prevalence, clinical significance, diagnosis and management of dyspnoea in critically ill, mechanically ventilated adult patients. It covers the definition, pathophysiology, epidemiology, short- and middle-term impact, detection and quantification, and prevention and treatment of dyspnoea. It represents a collaboration of the European Respiratory Society (ERS) and the European Society of Intensive Care Medicine (ESICM). Dyspnoea ranks among the most distressing experiences that human beings can endure. Approximately 40% of patients undergoing invasive mechanical ventilation in the intensive care unit (ICU) report dyspnoea, with an average intensity of 45 mm on a visual analogue scale from 0 to 100 mm. Although it shares many similarities with pain, dyspnoea can be far worse than pain in that it summons a primal fear response. As such, it merits universal and specific consideration. Dyspnoea must be identified, prevented and relieved in every patient. In the ICU, mechanically ventilated patients are at high risk of experiencing breathing difficulties because of their physiological status and, in some instances, because of mechanical ventilation itself. At the same time, mechanically ventilated patients have barriers to signalling their distress. Addressing this major clinical challenge mandates teaching and training, and involves ICU caregivers and patients. This is even more important because, as opposed to pain which has become a universal healthcare concern, very little attention has been paid to the identification and management of respiratory suffering in mechanically ventilated ICU patients.

Post-extubation high-flow nasal cannula oxygen therapy versus non-invasive ventilation in chronic obstructive pulmonary disease with hypercapnic respiratory failure

The sequential use of non-invasive ventilation (NIV) for weaning in hypercapnic respiratory failure patients is a recommended practice. However, the effectiveness of weaning on high-flow nasal cannula (HFNC) is unclear. Chronic obstructive pulmonary disease patients with hypercapnic respiratory failure who received invasive ventilation were screened for enrollment. This study was a single-center, prospective, randomized comparative study. The primary outcome was treatment failure within 72 hours after extubation. Patients who were screened positive for extubation were enrolled in the study and randomized into the HFNC group and the NIV group using a computer-generated simple randomization chart. Treatment failure was defined as a return to invasive mechanical ventilation or a switch in respiratory support modality (i.e., changing from HFNC to NIV or from NIV to HFNC). The study included 62 of the 72 patients. Treatment failure occurred in 8 patients (26.67%) in the HFNC group and 8 patients in the NIV group (25%) (p=0.881). The mean duration of intensive care unit stay in the HFNC group was 5.47±2.26 days and 6.56±3.39 in the NIV group (p=0.376). In the current study, HFNC was non-inferior to NIV in preventing post-extubation respiratory failure in chronic obstructive pulmonary disease patients, while HFNC had better treatment tolerance.

Prognostic factors for patients with hematologic malignancies admitted to the intensive care unit: is allogeneic transplantation still a risk factor?

The rate of intensive care unit (ICU) mortality in patients with hematologic malignancies is high. The risk factors for this were inconsistent across several previous studies, and there is currently no accepted consensus around risk factors for these patients. We aimed to identify which prognostic factors were associated with ICU mortality in critically ill patients with hematologic malignancies, nearly half of which were allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. In addition, we aimed to compare the characteristics and clinical outcomes of patients with and without allogenic allo-HSCT. In total, 217 patients with hematologic malignancies were enrolled consecutive, 119 (54.8%) of whom underwent HSCT (allo-HSCT: n = 115). All survivors were followed up with until August 1, 2022. The rate of ICU mortality in this cohort was 54.4%: 55.5 and 53.1% for the patients with and without HSCT, respectively (p = 0.724). The probabilities of survival after ICU admission were also comparable between the patients who had allo-HSCT and those who did not. A multivariable analysis revealed that cerebrovascular disease, hyperlactic acidemia on the day of ICU admission, lower platelet count, use of vasoactive drugs, and absence of noninvasive ventilation on the day of ICU admission were independent risk factors for ICU mortality. For patients with three to five of these risk factors, the rate of ICU mortality was as high as 84.6%, which was significantly higher than that of other patients. In this study, the ICU mortality rate in patients with hematologic malignancies was still high, particularly for those with multiple risk factors. However, allo-HSCT was not found to be a risk factor for ICU mortality.

Lessons from COVID-19 in the management of acute respiratory failure

Accumulated evidence supports the efficacy of noninvasive respiratory support therapies in coronavirus disease 2019 (COVID-19)-related acute hypoxaemic respiratory failure, alleviating admissions to intensive care units. Noninvasive respiratory support strategies, including high-flow oxygen therapy, continuous positive airway pressure via mask or helmet and noninvasive ventilation, can be alternatives that may avoid the need for invasive ventilation. Alternating different noninvasive respiratory support therapies and introducing complementary interventions, like self-proning, may improve outcomes. Proper monitoring is warranted to ensure the efficacy of the techniques and to avoid complications while supporting transfer to the intensive care unit. This article reviews the latest evidence on noninvasive respiratory support therapies in COVID-19-related acute hypoxaemic respiratory failure.

Incidence, causes, and predictors of unsuccessful decannulation following prolonged weaning

Background

Liberation from prolonged tracheostomy ventilation involves ventilator weaning and removal of the tracheal cannula (referred to as decannulation). This study evaluated the incidence, causes, and predictors of unsuccessful decannulation following prolonged weaning.

Methods

Observational retrospective cohort study of 532 prolonged mechanically ventilated, tracheotomized patients treated at a specialized weaning center between June 2013 and January 2021. We summarized the causes for unsuccessful decannulations and used a binary logistic regression analysis to derive and validate associated predictors.

Results

Failure to decannulate occurred in 216 patients (41%). The main causes were severe intensive care unit (ICU)-acquired dysphagia (64%), long-term ventilator dependence following weaning failure (41%), excessive respiratory secretions (12%), unconsciousness (4%), and airway obstruction (3%). Predictors of unsuccessful decannulation from any cause were age [odds ratio (OR) = 1.04 year^-1; 95% confidence interval (CI), 1.02-1.06; p < 0.01], body mass index [0.96 kg/m² (0.93-1.00); p = 0.027], Acute Physiology and Chronic Health Evaluation II (APACHE-II) score [1.05 (1.00-1.10); p = 0.036], pre-existing non-invasive home ventilation [3.57 (1.51-8.45); p < 0.01], percutaneous tracheostomies [0.49 (0.30-0.80); p < 0.01], neuromuscular diseases [4.28 (1.21-15.1); p = 0.024], and total mechanical ventilation duration [1.02 day^-1 (1.01-1.02); p < 0.01]. Regression models examined in subsets of patients with severe dysphagia and long-term ventilator dependence as the main reason for failure revealed little overlapping among predictors, which even showed opposite effects on the outcome. The application of non-invasive ventilation as a weaning technique contributed to successful decannulation in 96 of 221 (43%) long-term ventilator-dependent patients following weaning failure.

Conclusion

Failure to decannulate after prolonged weaning occurred in 41%, mainly resulting from persistent ICU-acquired dysphagia and long-term ventilator dependence following weaning failure, each associated with its own set of predictors.

Respiratory distress observation scales to predict weaning outcome

Background

Whether dyspnea is present before starting a spontaneous breathing trial (SBT) and whether it may affect the outcome of the SBT is unknown. Mechanical Ventilation—Respiratory Distress Observation Scale (MV-RDOS) has been proposed as a reliable surrogate of dyspnea in non-communicative intubated patients. In the present study, we sought (1) to describe the evolution of the MV-RDOS during a SBT and (2) to investigate whether MV-RDOS can predict the outcome of the SBT.

Methods

Prospective, single-center study in a twenty-two bed ICU in a tertiary center. Patients intubated since more 48 h who had failed a first SBT were eligible if they meet classical readiness to wean criteria. The MV-RDOS was assessed before, at 2-min, 15-min and 30-min (end) of the SBT. The presence of clinically important dyspnea was inferred by a MV-RDOS value ≥  2.6.

Results

Fifty-eight patients (age 63 [51–70], SAPS II 66 [51–76]; med [IQR]) were included. Thirty-three (57%) patients failed the SBT, whose 18 (55%) failed before 15-min. Twenty-five (43%) patients successfully passed the SBT. A MV-RDOS ≥ 2.6 was present in ten (17%) patients before to start the SBT. All these ten patients subsequently failed the SBT. A MV-RDOS ≥ 2.6 at 2-min predicted a SBT failure with a 51% sensibility and a 88% specificity (AUC 0.741 95% confidence interval [CI] 0.616–0.866, p = 0.002). Best cut-off value at 2-min was 4.3 and predicted SBT failure with a 27% sensibility and a 96% specificity.

Conclusion

Despite patients met classical readiness to wean criteria, respiratory distress assessed with the MV-RDOS was frequent at the beginning of SBT. Measuring MV-RDOS before to initiate a SBT could avoid undue procedure and reduce patient’s exposure to unnecessary mechanical ventilation weaning failure and distress.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04028-7.

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

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

: A Post-Hoc Analysis of a Randomized Clinical Trial

RATIONALE

Whereas non-invasive ventilation (NIV) may prevent reintubation in patients at high-risk of extubation failure in intensive care units (ICUs), this oxygenation strategy has not been specifically assessed in obese patients.

OBJECTIVES

We hypothesized that NIV may decrease the risk of reintubation in obese patients compared with high-flow nasal oxygen (HFNO).

METHODS

Post-hoc analysis of a multicenter, randomized, controlled trial (not pre-specified) comparing NIV alternating with HFNO versus HFNO alone after extubation, with the aim of assessing NIV effects according to patient body-mass index (BMI).

MEASUREMENTS AND MAIN RESULTS

Among 623 patients at high-risk of extubation failure, 206 (33%) were obese (BMI≥30 kg/m2), 204 (33%) were overweight (25≤BMI<30), and 213 (34%) were normal or underweight (BMI<25). Significant heterogeneity of NIV effects on the rate of reintubation was found according to BMI (Pinteraction=0.007). Reintubation rates at day 7 were significantly lower with NIV alternating with HFNO than with HFNO alone in obese or overweight patients: 7% (15/204) vs. 20% (41/206); difference, -13%; [95% CI, -19 to -6]; P=0.0002; whereas it did not significantly differ in normal or underweight patients. In-ICU mortality was significantly lower with NIV than with HFNO alone in obese or overweight patients (2% vs. 9%; difference, -6%; [95% CI, -11 to -2]; P=0.006).

CONCLUSIONS

Prophylactic NIV alternating with HFNO immediately after extubation significantly decreased the risk of reintubation and death as compared with HFNO alone in obese or overweight patients at high-risk of extubation failure. By contrast, NIV was not effective in normal or underweight patients.

Model-based estimation of negative inspiratory driving pressure in patients receiving invasive NAVA mechanical ventilation

BACKGROUND

Optimisation of mechanical ventilation (MV) and weaning requires insight into underlying patient breathing effort. Current identifiable models effectively describe lung mechanics, such as elastance (E) and resistance (R) at the bedside in sedated patients, but are less effective when spontaneous breathing is present. This research derives and regularises a single compartment model to identify patient-specific inspiratory effort.

METHODS

Constrained second-order b-spline basis functions (knot width 0.05 s) are used to describe negative inspiratory drive (Pp, cmH₂O) as a function of time. Breath-breath Pp are identified with single E and R values over inspiration and expiration from n = 20 breaths for N = 22 patients on NAVA ventilation. Pp is compared to measured electrical activity of the diaphragm (Eadi) and published results.

RESULTS

Average per-patient root-mean-squared model fit error was (median [interquartile range, IQR]) 0.9 [0.6-1.3] cmH₂O, and average per-patient median Pp was -3.9 [-4.5- -3.0] cmH₂O, with range -7.9 - -1.9 cmH₂O. Per-patient E and R were 16.4 [13.6-21.8] cmH₂O/L and 9.2 [6.4-13.1] cmH₂O.s/L, respectively. Most patients showed an inspiratory volume threshold beyond which Pp started to return to baseline, and Pp at peak Eadi (end-inspiration) was often strongly correlated with peak Eadi (R²=0.25-0.86). Similarly, average transpulmonary pressure was consistent breath-breath in most patients, despite differences in peak Eadi and thus peak airway pressure.

CONCLUSIONS

The model-based inspiratory effort aligns with electrical muscle activity and published studies showing neuro-muscular decoupling as a function of pressure and/or volume. Consistency in coupling/dynamics were patient-specific. Quantification of patient and ventilator work of breathing contributions may aid optimisation of MV modes and weaning.

Non-invasive ventilation alternating with high-flow nasal oxygen versus high-flow nasal oxygen alone after extubation in COPD patients: a post hoc analysis of a randomized controlled trial

Background

Several randomized clinical trials have shown that non-invasive ventilation (NIV) applied immediately after extubation may prevent reintubation in patients at high-risk of extubation failure. However, most of studies included patients with chronic respiratory disorders as well as patients without underlying respiratory disease. To date, no study has shown decreased risk of reintubation with prophylactic NIV after extubation among patients with chronic obstructive pulmonary disease (COPD). We hypothesized that prophylactic NIV after extubation may decrease the risk of reintubation in COPD patients as compared with high-flow nasal oxygen. We performed a post hoc subgroup analysis of COPD patients included in a multicenter, randomized, controlled trial comparing prophylactic use of NIV alternating with high-flow nasal oxygen versus high-flow nasal oxygen alone immediately after extubation.

Results

Among the 651 patients included in the original study, 150 (23%) had underlying COPD including 86 patients treated with NIV alternating with high-flow nasal oxygen and 64 patients treated with high-flow nasal oxygen alone. The reintubation rate was 13% (11 out of 86 patients) with NIV and 27% (17 out of 64 patients) with high-flow nasal oxygen alone [difference, − 14% (95% CI − 27% to − 1%); p = 0.03]. Whereas reintubation rates were significantly lower with NIV than with high-flow nasal oxygen alone at 72 h and until ICU discharge, mortality in ICU did not differ between groups: 6% (5/86) with NIV vs. 9% (6/64) with high-flow nasal oxygen alone [difference − 4% (95% CI − 14% to 5%); p = 0.40].

Conclusions

In COPD patients, prophylactic NIV alternating with high-flow nasal oxygen significantly decreased the risk of reintubation compared with high-flow nasal oxygen alone.

Trial registration The study was registered at http://www.clinicaltrials.gov with the trial registration number NCT03121482 (20 April 2017)

THE DETECTION AND ESTIMATION OF THE AIR LEAKAGE IN NONINVASIVE VENTILaTION: PLATFORM STUDY

Although noninvasive ventilation has been increasingly used in clinics and homes to treat respiratory diseases, the problem of air leaks should not be neglected because they may affect the performance of the ventilation and even pose a threat to life. The detection and estimation of the leakage are required to implement auto-compensation, which is important in the development of intelligent ventilation. In this study, the methods of detection and estimation of the leakage were established and validated. Ventilation experiments were performed based on the established experimental platform. The air flow and pressure were detected at different locations of the airway to determine the relationship between the leakage and the other variables. The leakage was estimated using linear predictor models. The curves describing the relationships among pressure, flow and volume changed regularly with the leakage. For pressure-controlled ventilation, the leakage could be estimated by the detected peak flow and by the ventilation volume of one breathing cycle. The methods for the leakage estimation were validated. Volume-controlled ventilation was also studied. Although the leakage could be estimated using the detected peak pressure, the limitation of volume-controlled ventilation was obvious for noninvasive ventilation (NIV). Leaks could be detected and estimated using a linear predictor model via the flow/pressure curve. The use of this model is a potential method for the auto-compensation of noninvasive ventilation.

The role of non-invasive ventilation in weaning and decannulating critically ill patients with tracheostomy: A narrative review of the literature

INTRODUCTION

Invasive mechanical ventilation (IMV) is associated with several complications. Placement of a long-term airway (tracheostomy) is also associated with short and long-term risks for patients. Nevertheless, tracheostomies are placed to help reduce the duration of IMV, facilitate weaning and eventually undergo successful decannulation.

METHODS

We performed a narrative review by searching PubMed, Embase and Medline databases to identify relevant citations using the search terms (with synonyms and closely related words) "non-invasive ventilation", "tracheostomy" and "weaning". We identified 13 publications comprising retrospective or prospective studies in which non-invasive ventilation (NIV) was one of the strategies used during weaning from IMV and/or tracheostomy decannulation.

RESULTS

In some studies, patients with tracheostomies represented a subgroup of patients on IMV. Most of the studies involved patients with underlying cardiopulmonary comorbidities and conditions, and primarily involved specialized weaning centres. Not all studies provided data on decannulation, although those which did, report high success rates for weaning and decannulation when using NIV as an adjunct to weaning patient off ventilatory support. However, a significant percentage of patients still needed home NIV after discharge.

CONCLUSIONS

The review supports a potential role for NIV in weaning patients with a tracheostomy either off the ventilator and/or with its decannulation. Additional research is needed to develop weaning protocols and better characterize the role of NIV during weaning.

Effect of Postextubation High-Flow Nasal Oxygen With Noninvasive Ventilation vs High-Flow Nasal Oxygen Alone on Reintubation Among Patients at High Risk of Extubation Failure: A Randomized Clinical Trial

IMPORTANCE

High-flow nasal oxygen may prevent postextubation respiratory failure in the intensive care unit (ICU). The combination of high-flow nasal oxygen with noninvasive ventilation (NIV) may be an optimal strategy of ventilation to avoid reintubation.

OBJECTIVE

To determine whether high-flow nasal oxygen with prophylactic NIV applied immediately after extubation could reduce the rate of reintubation, compared with high-flow nasal oxygen alone, in patients at high risk of extubation failure in the ICU.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter randomized clinical trial conducted from April 2017 to January 2018 among 641 patients at high risk of extubation failure (ie, older than 65 years or with an underlying cardiac or respiratory disease) at 30 ICUs in France; follow-up was until April 2018.

INTERVENTIONS

Patients were randomly assigned to high-flow nasal oxygen alone (n = 306) or high-flow nasal oxygen alternating with NIV (n = 342) immediately after extubation.

MAIN OUTCOMES AND MEASURES

The primary outcome was the proportion of patients reintubated at day 7; secondary outcomes included postextubation respiratory failure at day 7, reintubation rates up until ICU discharge, and ICU mortality.

RESULTS

Among 648 patients who were randomized (mean [SD] age, 70 [10] years; 219 women [34%]), 641 patients completed the trial. The reintubation rate at day 7 was 11.8% (95% CI, 8.4%-15.2%) (40/339) with high-flow nasal oxygen and NIV and 18.2% (95% CI, 13.9%-22.6%) (55/302) with high-flow nasal oxygen alone (difference, -6.4% [95% CI, -12.0% to -0.9%]; P = .02). Among the 11 prespecified secondary outcomes, 6 showed no significant difference. The proportion of patients with postextubation respiratory failure at day 7 (21% vs 29%; difference, -8.7% [95% CI, -15.2% to -1.8%]; P = .01) and reintubation rates up until ICU discharge (12% vs 20%, difference -7.4% [95% CI, -13.2% to -1.8%]; P = .009) were significantly lower with high-flow nasal oxygen and NIV than with high-flow nasal oxygen alone. ICU mortality rates were not significantly different: 6% with high-flow nasal oxygen and NIV and 9% with high-flow nasal oxygen alone (difference, -2.4% [95% CI, -6.7% to 1.7%]; P = .25).

CONCLUSIONS AND RELEVANCE

In mechanically ventilated patients at high risk of extubation failure, the use of high-flow nasal oxygen with NIV immediately after extubation significantly decreased the risk of reintubation compared with high-flow nasal oxygen alone.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03121482.

Noninvasive ventilation during weaning from prolonged mechanical ventilation

BACKGROUND AND OBJECTIVE

Non invasive ventilation (NIV) is currently employed for weaning from invasive ventilation (IMV) in the acute setting but its use for weaning from prolonged ventilation is still occasional and not standardized. We wanted to evaluate whether a combined protocol of NIV and decannulation in tracheostomized patients needing prolonged mechanical ventilation was feasible and what would be the one-year outcome.

METHODS

We studied patients still dependent from invasive mechanical ventilation with the following inclusion criteria: a) tolerance of at least 8h of unsupported breathing, b) progressive hypercapnia/acidosis after invasive ventilation discontinuation, c) good adaptation to NIV, d) favorable criteria for decannulation. These patients were switched from IMV to NIV and decannulated; then they were discharged on home NIV and followed-up for one year in order to evaluate survival and complications rate.

RESULTS

Data from patients consecutively admitted to a weaning unit were prospectively collected between 2005 and 2018. Out of 587 patients admitted over that period, 341 were liberated from prolonged mechanical ventilation. Fifty-one out of 147 unweaned patients (35%) were eligible for the protocol but only 46 were enrolled. After a mean length of stay of 35 days they were decannulated and discharged on domiciliary NIV. After one year, 38 patients were still alive (survival rate 82%) and 37 were using NIV with good adherence (only one patient was switched again to invasive ventilation).

CONCLUSIONS

NIV applied to patients with failed weaning from prolonged IMV is feasible and can facilitate the decannulation process. Patients successfully completing this process show good survival rates and few complications.

Ventilatory support after extubation in critically ill patients

The periextubation period represents a crucial moment in the management of critically ill patients. Extubation failure, defined as the need for reintubation within 2-7 days after a planned extubation, is associated with prolonged mechanical ventilation, increased incidence of ventilator-associated pneumonia, longer intensive care unit and hospital stays, and increased mortality. Conventional oxygen therapy is commonly used after extubation. Additional methods of non-invasive respiratory support, such as non-invasive ventilation and high-flow nasal therapy, can be used to avoid reintubation. The aim of this Review is to describe the pathophysiological mechanisms of postextubation respiratory failure and the available techniques and strategies of respiratory support to avoid reintubation. We summarise and discuss the available evidence supporting the use of these strategies to achieve a tailored therapy for an individual patient at the bedside.

Benefits of non-invasive ventilation in acute hypercapnic respiratory failure

Non-invasive ventilation (NIV) with bilevel positive airway pressure is a non-invasive technique, which refers to the provision of ventilatory support through the patient's upper airway using a mask or similar device. This technique is successful in correcting hypoventilation. It has become widely accepted as the standard treatment for patients with hypercapnic respiratory failure (HRF). Since the 1980s, NIV has been used in intensive care units and, after initial anecdotal reports and larger series, a number of randomized trials have been conducted. Data from these trials have shown that NIV is a valuable treatment for HRF. This review aims to explore the principal areas in which NIV can be useful, focusing particularly on patients with acute HRF (AHRF). We will update the evidence base with the goal of supporting clinical practice. We provide a practical description of the main indications for NIV in AHRF and identify the group of patients with hypercapnic failure who will benefit most from the application of NIV.

The patient needing prolonged mechanical ventilation: a narrative review

BACKGROUND

Progress in management has improved hospital mortality of patients admitted to the intensive care units, but also the prevalence of those patients needing weaning from prolonged mechanical ventilation, and of ventilator assisted individuals. The result is a number of difficult clinical and organizational problems for patients, caregivers and health services, as well as high human and financial resources consumption, despite poor long-term outcomes. An effort should be made to improve the management of these patients. This narrative review summarizes the main concepts in this field.

MAIN BODY

There is great variability in terminology and definitions of prolonged mechanical ventilation.There have been several recent developments in the field of prolonged weaning: ventilatory strategies, use of protocols, early mobilisation and physiotherapy, specialised weaning units.There are few published data on discharge home rates, need of home mechanical ventilation, or long-term survival of these patients.Whether artificial nutritional support improves the outcome for these chronic critically ill patients, is unclear and controversial how these data are reported on the optimal time of initiation of parenteral vs enteral nutrition.There is no consensus on time of tracheostomy or decannulation. Despite several individualized, non-comparative and non-validated decannulation protocols exist, universally accepted protocols are lacking as well as randomised controlled trials on this critical issue. End of life decisions should result from appropriate communication among professionals, patients and surrogates and national legislations should give clear indications.

CONCLUSION

Present medical training of clinicians and locations like traditional intensive care units do not appear enough to face the dramatic problems posed by these patients. The solutions cannot be reserved to professionals but must involve also families and all other stakeholders. Large multicentric, multinational studies on several aspects of management are needed.

Physiological predictors of respiratory and cough assistance needs after extubation

Background

Identifying patients at high risk of post-extubation acute respiratory failure requiring respiratory or mechanical cough assistance remains challenging. Here, our primary aim was to evaluate the accuracy of easily collected parameters obtained before or just after extubation in predicting the risk of post-extubation acute respiratory failure requiring, at best, noninvasive mechanical ventilation (NIV) and/or mechanical cough assistance and, at worst, reintubation after extubation.

Methods

We conducted a multicenter prospective, open-label, observational study from April 2012 through April 2015. Patients who passed a weaning test after at least 72 h of endotracheal mechanical ventilation (MV) were included. Just before extubation, spirometry and maximal pressures were measured by a technician. The results were not disclosed to the bedside physicians. Patients were followed until discharge or death.

Results

Among 3458 patients admitted to the ICU, 730 received endotracheal MV for longer than 72 h and were then extubated; among these, 130 were included. At inclusion, the 130 patients had mean ICU stay and endotracheal MV durations both equal to 11 ± 4.2 days. After extubation, 36 patients required curative NIV, 7 both curative NIV and mechanical cough assistance, and 8 only mechanical cough assistance; 6 patients, all of whom first received NIV, required reintubation within 48 h. The group that required NIV after extubation had a significantly higher proportion of patients with chronic respiratory disease (P = 0.015), longer endotracheal MV duration at inclusion, and lower Medical Research Council (MRC) score (P = 0.02, P = 0.01, and P = 0.004, respectively). By multivariate analysis, forced vital capacity (FVC) and peak cough expiratory flow (PCEF) were independently associated with (NIV) and/or mechanical cough assistance and/or reintubation after extubation. Areas under the ROC curves for pre-extubation PCEF and FVC were 0.71 and 0.76, respectively.

Conclusion

In conclusion, FVC measured before extubation correlates closely with FVC after extubation and may serve as an objective predictor of post-extubation respiratory failure requiring NIV and/or mechanical cough assistance and/or reintubation in heterogeneous populations of medical ICU patients.

ClinicalTrials.gov as #NCT01564745

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0360-3) contains supplementary material, which is available to authorized users.

Official ERS/ATS clinical practice guidelines: noninvasive ventilation for acute respiratory failure

Noninvasive mechanical ventilation (NIV) is widely used in the acute care setting for acute respiratory failure (ARF) across a variety of aetiologies. This document provides European Respiratory Society/American Thoracic Society recommendations for the clinical application of NIV based on the most current literature.The guideline committee was composed of clinicians, methodologists and experts in the field of NIV. The committee developed recommendations based on the GRADE (Grading, Recommendation, Assessment, Development and Evaluation) methodology for each actionable question. The GRADE Evidence to Decision framework in the guideline development tool was used to generate recommendations. A number of topics were addressed using technical summaries without recommendations and these are discussed in the supplementary material.This guideline committee developed recommendations for 11 actionable questions in a PICO (population-intervention-comparison-outcome) format, all addressing the use of NIV for various aetiologies of ARF. The specific conditions where recommendations were made include exacerbation of chronic obstructive pulmonary disease, cardiogenic pulmonary oedema, de novo hypoxaemic respiratory failure, immunocompromised patients, chest trauma, palliation, post-operative care, weaning and post-extubation.This document summarises the current state of knowledge regarding the role of NIV in ARF. Evidence-based recommendations provide guidance to relevant stakeholders.

Official ERS/ATS clinical practice guidelines: noninvasive ventilation for acute respiratory failure

Noninvasive mechanical ventilation (NIV) is widely used in the acute care setting for acute respiratory failure (ARF) across a variety of aetiologies. This document provides European Respiratory Society/American Thoracic Society recommendations for the clinical application of NIV based on the most current literature.The guideline committee was composed of clinicians, methodologists and experts in the field of NIV. The committee developed recommendations based on the GRADE (Grading, Recommendation, Assessment, Development and Evaluation) methodology for each actionable question. The GRADE Evidence to Decision framework in the guideline development tool was used to generate recommendations. A number of topics were addressed using technical summaries without recommendations and these are discussed in the supplementary material.This guideline committee developed recommendations for 11 actionable questions in a PICO (population-intervention-comparison-outcome) format, all addressing the use of NIV for various aetiologies of ARF. The specific conditions where recommendations were made include exacerbation of chronic obstructive pulmonary disease, cardiogenic pulmonary oedema, de novo hypoxaemic respiratory failure, immunocompromised patients, chest trauma, palliation, post-operative care, weaning and post-extubation.This document summarises the current state of knowledge regarding the role of NIV in ARF. Evidence-based recommendations provide guidance to relevant stakeholders.

Noninvasive ventilation during the weaning process in chronically critically ill patients

Chronically critically ill patients often undergo prolonged mechanical ventilation. The role of noninvasive ventilation (NIV) during weaning of these patients remains unclear. The aim of this study was to determine the value of NIV and whether a parameter can predict the need for NIV in chronically critically ill patients during the weaning process.

We conducted a prospective study that included chronically critically ill patients admitted to Spanish respiratory care units. The weaning method used consisted of progressive periods of spontaneous breathing trials. Patients were transferred to NIV when it proved impossible to increase the duration of spontaneous breathing trials beyond 18 h.

231 chronically critically ill patients were included in the study. 198 (85.71%) patients achieved weaning success (mean weaning time 25.45±16.71 days), of whom 40 (21.4%) needed NIV during the weaning process. The variable which predicted the need for NIV was arterial carbon dioxide tension at respiratory care unit admission (OR 1.08 (95% CI 1.01–1.15), p=0.013), with a cut-off point of 45.5 mmHg (sensitivity 0.76, specificity 0.67, positive predictive value 0.76, negative predictive value 0.97).

NIV is a useful tool during weaning in chronically critically ill patients. Hypercapnia despite mechanical ventilation at respiratory care unit admission is the main predictor of the need for NIV during weaning.

NIV is a useful tool during weaning in chronic critically ill patients independent of their premorbid conditionhttp://ow.ly/j4Av304sEoJ

Can resistive breathing injure the lung? Implications for COPD exacerbations

In obstructive lung diseases, airway inflammation leads to bronchospasm and thus resistive breathing, especially during exacerbations. This commentary discusses experimental evidence that resistive breathing per se (the mechanical stimulus) in the absence of underlying airway inflammation leads to lung injury and inflammation (mechanotransduction). The potential implications of resistive breathing-induced mechanotrasduction in COPD exacerbations are presented along with the available clinical evidence.

Noninvasive versus invasive mechanical ventilation for immunocompromised patients with acute respiratory failure: a systematic review and meta-analysis

Background

To determine the effects of noninvasive mechanical ventilation (NIV) compared with invasive mechanical ventilation (IMV) as the initial mechanical ventilation on clinical outcomes when used for treatment of acute respiratory failure (ARF) in immunocompromised patients.

Methods

We searched PubMed, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), the Chinese Biomedical Literature Database (CBM) and other databases. Subgroup analyses by disease severity and causes of immunodeficiency were also conducted.

Results

Thirteen observational studies with a total of 2552 patients were included. Compared to IMV, NIV was shown to significantly reduce in-hospital mortality (OR 0.43, 95 % CI 0.23 to 0.80, P value = 0.007) and 30-day mortality (OR 0.34, 95 % CI 0.20 to 0.61, P value < 0.0001) in overall analysis. Subgroup analysis showed NIV had great advantage over IMV for less severe, AIDS, BMT and hematological malignancies patients in reducing mortality and duration of ICU stay.

Conclusions

The overall evidence we obtained shows NIV does more benefits or at least no harm to ARF patients with certain causes of immunodeficiency or who are less severe.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0289-y) contains supplementary material, which is available to authorized users.

The optimum timing to wean invasive ventilation for patients with AECOPD or COPD with pulmonary infection

COPD is characterized by a progressive decline in lung function and mental and physical comorbidities. It is a significant burden worldwide due to its growing prevalence, comorbidities, and mortality. Complication by bronchial-pulmonary infection causes 50%-90% of acute exacerbations of COPD (AECOPD), which may lead to the aggregation of COPD symptoms and the development of acute respiratory failure. Non-invasive or invasive ventilation (IV) is usually implemented to treat acute respiratory failure. However, ventilatory support (mainly IV) should be discarded as soon as possible to prevent the onset of time-dependent complications. To withdraw IV, an optimum timing has to be selected based on weaning assessment and spontaneous breathing trial or replacement of IV by non-IV at pulmonary infection control window. The former method is more suitable for patients with AECOPD without significant bronchial-pulmonary infection while the latter method is more suitable for patients with AECOPD with acute significant bronchial-pulmonary infection.

Noninvasive ventilation practice patterns for acute respiratory failure in Canadian tertiary care centres: A descriptive analysis

BACKGROUND

The extent of noninvasive ventilation (NIV) use for patients with acute respiratory failure in Canadian hospitals, indications for use and associated outcomes are unknown.

OBJECTIVE

To describe NIV practice variation in the acute setting.

METHODS

A prospective observational study involving 11 Canadian tertiary care centres was performed. Data regarding NIV indication, mode and outcomes were collected for all adults (>16 years of age) treated with NIV for acute respiratory failure during a four-week period (between February and August 2011). Logistic regression with site as a random effect was used to examine the association between preselected predictors and mortality or intubation.

RESULTS

A total of 330 patients (mean [± SD] 30±12 per centre) were included. The most common indications for NIV initiation were pulmonary edema (104 [31.5%]) and chronic obstructive pulmonary disease (99 [30.0%]). Significant differences in indications for NIV use across sites, specialty of ordering physician and location of NIV initiation were noted. Although intubation rates were not statistically different among sites (range 10.3% to 45.4%), mortality varied significantly (range 6.7% to 54.5%; P=0.006). In multivariate analysis, the most significant independent predictor of avoiding intubation was do-not-resuscitate status (OR 0.11 [95% CI 0.03 to 0.37]).

CONCLUSION

Significant variability existed in NIV use and associated outcomes among Canadian tertiary care centres. Assignment of do-not-resuscitate status prevented intubation.

Noninvasive positive pressure ventilation for acute respiratory failure following upper abdominal surgery

BACKGROUND

Each year, more than four million abdominal surgeries are performed in the US and over 250,000 in England. Acute respiratory failure, a common complication that can affect 30% to 50% of people after upper abdominal surgery, can lead to significant morbidity and mortality. Noninvasive ventilation has been associated with lower rates of tracheal intubation in adults with acute respiratory failure, thus reducing the incidence of complications and mortality. This review compared the effectiveness and safety of noninvasive positive pressure ventilation (NPPV) versus standard oxygen therapy in the treatment of acute respiratory failure after upper abdominal surgery.

OBJECTIVES

To assess the effectiveness and safety of noninvasive positive pressure ventilation (NPPV), that is, continuous positive airway pressure (CPAP) or bilevel NPPV, in reducing mortality and the rate of tracheal intubation in adults with acute respiratory failure after upper abdominal surgery, compared to standard therapy (oxygen therapy), and to assess changes in arterial blood gas levels, hospital and intensive care unit (ICU) length of stay, gastric insufflation, and anastomotic leakage.

SEARCH METHODS

The date of the last search was 12 May 2015. We searched the following databases: the Cochrane Handbook for Systematic Reviews of Interventions (CENTRAL) (2015, Issue 5), MEDLINE (Ovid SP, 1966 to May 2015), EMBASE (Ovid SP, 1974 to May 2015); the physiotherapy evidence database (PEDro) (1999 to May 2015); the Cumulative Index to Nursing and Allied Health Literature (CINAHL, EBSCOhost, 1982 to May 2015), and LILACS (BIREME, 1986 to May 2015). We reviewed reference lists of included studies and contacted experts. We also searched grey literature sources. We checked databases of ongoing trials such as www.controlled-trials.com/ and www.trialscentral.org/. We did not apply language restrictions.

SELECTION CRITERIA

We selected randomized or quasi-randomized controlled trials involving adults with acute respiratory failure after upper abdominal surgery who were treated with CPAP or bilevel NPPV with, or without, drug therapy as standard medical care, compared to adults treated with oxygen therapy with, or without, standard medical care.

DATA COLLECTION AND ANALYSIS

Two authors independently selected and abstracted data from eligible studies using a standardized form. We evaluated study quality by assessing allocation concealment; random sequence generation; incomplete outcome data; blinding of participants, personnel, and outcome assessors; selective reporting; and adherence to the intention-to-treat (ITT) principle.

MAIN RESULTS

We included two trials involving 269 participants. The participants were mostly men (67%); the mean age was 65 years. The trials were conducted in China and Italy (one was a multicentre trial). Both trials included adults with acute respiratory failure after upper abdominal surgery. We judged both trials at high risk of bias. Compared to oxygen therapy, CPAP or bilevel NPPV may reduce the rate of tracheal intubation (risk ratio (RR) 0.25; 95% confidence interval (CI) 0.08 to 0.83; low quality evidence) with a number needed to treat for an additional beneficial outcome of 11. There was very low quality evidence that the intervention may also reduce ICU length of stay (mean difference (MD) -1.84 days; 95% CI -3.53 to -0.15). We found no differences for mortality (low quality evidence) and hospital length of stay. There was insufficient evidence to be certain that CPAP or NPPV had an effect on anastomotic leakage, pneumonia-related complications, and sepsis or infections. Findings from one trial of 60 participants suggested that bilevel NPPV, compared to oxygen therapy, may improve blood gas levels and blood pH one hour after the intervention (partial pressure of arterial oxygen (PaO2): MD 22.5 mm Hg; 95% CI 17.19 to 27.81; pH: MD 0.06; 95% CI 0.01 to 0.11; partial pressure of arterial carbon dioxide (PCO2) levels (MD -9.8 mm Hg; 95% CI -14.07 to -5.53). The trials included in this systematic review did not present data on the following outcomes that we intended to assess: gastric insufflation, fistulae, pneumothorax, bleeding, skin breakdown, eye irritation, sinus congestion, oronasal drying, and patient-ventilator asynchrony.

AUTHORS' CONCLUSIONS

The findings of this review indicate that CPAP or bilevel NPPV is an effective and safe intervention for the treatment of adults with acute respiratory failure after upper abdominal surgery. However, based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, the quality of the evidence was low or very low. More good quality studies are needed to confirm these findings.

Noninvasive positive pressure ventilation is required following extubation at the pulmonary infection control window: a prospective observational study

INTRODUCTION

Timely extubation and sequential invasive to noninvasive positive pressure ventilation (NPPV) at the pulmonary infection control (PIC) window is beneficial for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). However, it remains unclear whether patients can breathe independently at the PIC window and if NPPV is indeed necessary after extubation.

OBJECTIVES

To assess whether AECOPD patients can breathe independently at the PIC window and thus whether NPPV is necessary after extubation.

METHODS

We performed a prospective observational study at a university hospital during a 9-month period. We used the spontaneous breathing trial (SBT) to assess whether each patient could breathe independently at the PIC window, then performed extubation. Patients who passed the SBT received venturi oxygen therapy only, whereas those that failed received NPPV. However, if the former showed respiratory distress, they too received NPPV. The primary outcome variables were SBT pass/fail, the demand for NPPV and rate of reintubation within 72 h following extubation.

RESULTS

In all, 23 patients were enrolled, 15 (65%) of which passed the SBT. Of these, 12 (80%) developed respiratory distress after extubation and required NPPV (one of whom required reintubation). Of the eight patients that failed, one received reintubation after NPPV. The reintubation rates within 72 h following extubation of SBT-pass (7%) and SBT-fail (13%) patients were comparable.

CONCLUSION

Our results provide experimental evidence that most AECOPD patients can breathe independently at the PIC window, but nonetheless develop respiratory distress and thus require NPPV following extubation.

Noninvasive positive-pressure ventilation as a weaning strategy for intubated adults with respiratory failure

BACKGROUND

Noninvasive positive-pressure ventilation (NPPV) provides ventilatory support without the need for an invasive airway. Interest has emerged in using NPPV to facilitate earlier removal of an endotracheal tube and to decrease complications associated with prolonged intubation.

OBJECTIVES

We evaluated studies in which invasively ventilated adults with respiratory failure of any cause (chronic obstructive pulmonary disease (COPD), non-COPD, postoperative, nonoperative) were weaned by means of early extubation followed by immediate application of NPPV or continued IPPV weaning. The primary objective was to determine whether the noninvasive positive-pressure ventilation (NPPV) strategy reduced all-cause mortality compared with invasive positive-pressure ventilation (IPPV) weaning. Secondary objectives were to ascertain differences between strategies in proportions of weaning failure and ventilator-associated pneumonia (VAP), intensive care unit (ICU) and hospital length of stay (LOS), total duration of mechanical ventilation, duration of mechanical support related to weaning, duration of endotracheal mechanical ventilation (ETMV), frequency of adverse events (related to weaning) and overall quality of life. We planned sensitivity and subgroup analyses to assess (1) the influence on mortality and VAP of excluding quasi-randomized trials, and (2) effects on mortality and weaning failure associated with different causes of respiratory failure (COPD vs. mixed populations).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 5, 2013), MEDLINE (January 1966 to May 2013), EMBASE (January 1980 to May 2013), proceedings from four conferences, trial registration websites and personal files; we contacted authors to identify trials comparing NPPV versus conventional IPPV weaning.

SELECTION CRITERIA

Randomized and quasi-randomized trials comparing early extubation with immediate application of NPPV versus IPPV weaning in intubated adults with respiratory failure.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and abstracted data according to prespecified criteria. Sensitivity and subgroup analyses assessed (1) the impact of excluding quasi-randomized trials, and (2) the effects on selected outcomes noted with different causes of respiratory failure.

MAIN RESULTS

We identified 16 trials, predominantly of moderate to good quality, involving 994 participants, most with chronic obstructive pulmonary disease (COPD). Compared with IPPV weaning, NPPV weaning significantly decreased mortality. The benefits for mortality were significantly greater in trials enrolling exclusively participants with COPD (risk ratio (RR) 0.36, 95% confidence interval (CI) 0.24 to 0.56) versus mixed populations (RR 0.81, 95% CI 0.47 to 1.40). NPPV significantly reduced weaning failure (RR 0.63, 95% CI 0.42 to 0.96) and ventilator-associated pneumonia (RR 0.25, 95% CI 0.15 to 0.43); shortened length of stay in an intensive care unit (mean difference (MD) -5.59 days, 95% CI -7.90 to -3.28) and in hospital (MD -6.04 days, 95% CI -9.22 to -2.87); and decreased the total duration of ventilation (MD -5.64 days, 95% CI -9.50 to -1.77) and the duration of endotracheal mechanical ventilation (MD - 7.44 days, 95% CI -10.34 to -4.55) amidst significant heterogeneity. Noninvasive weaning also significantly reduced tracheostomy (RR 0.19, 95% CI 0.08 to 0.47) and reintubation (RR 0.65, 95% CI 0.44 to 0.97) rates. Noninvasive weaning had no effect on the duration of ventilation related to weaning. Exclusion of a single quasi-randomized trial did not alter these results. Subgroup analyses suggest that the benefits for mortality were significantly greater in trials enrolling exclusively participants with COPD versus mixed populations.

AUTHORS' CONCLUSIONS

Summary estimates from 16 trials of moderate to good quality that included predominantly participants with COPD suggest that a weaning strategy that includes NPPV may reduce rates of mortality and ventilator-associated pneumonia without increasing the risk of weaning failure or reintubation.

Neuroanesthesia and Intensive Care A meta-analysis of noninvasive weaning to facilitate liberation from mechanical ventilation

PURPOSE

To summarize the evidence comparing noninvasive positive pressure ventilation (NPPV) and invasive positive pressure ventilation (IPPV) weaning on mortality, ventilator associated pneumonia and the total duration of mechanical ventilation among invasively ventilated adults with respiratory failure.

SOURCE

Meta-analysis of randomized and quasi-randomized studies comparing early extubation with immediate application of NPPV to IPPV weaning. We selected randomized studies that 1) included adults, with respiratory failure, invasively ventilated for at least 24 hr; 2) compared extubation with immediate application of NPPV to weaning using IPPV; and 3) reported at least one clinically important outcome.

PRINCIPAL FINDINGS

We searched MEDLINE (1966 to 2003), EMBASE (1980 to 2003) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003) for randomized controlled trials comparing NPPV and IPPV weaning. Additional data sources included personal files, conference proceedings and author contact. Two reviewers independently assessed trial quality and abstracted data. Five studies enrolling 171 patients demonstrated that compared to IPPV, noninvasive weaning decreased mortality (relative risk, 0.41 [95% confidence interval [CI] 0.22-0.76]), ventilator associated pneumonia (relative risk, 0.28 [95% CI 0.09-0.85]) and the total duration of mechanical ventilation (weighted mean difference, -7.33 days [95% CI -11.45 to -3.22 days]).

CONCLUSIONS

In the absence of a large randomized controlled trial, this meta-analysis demonstrated a consistent positive effect of noninvasive weaning on mortality. Notwithstanding, the use of NPPV to facilitate weaning, in mechanically ventilated patients, with predominantly chronic obstructive pulmonary disease, is associated with promising, but insufficient, evidence of net clinical benefit at present.

Low mechanical ventilation times and reintubation rates associated with a specific weaning protocol in an intensive care unit setting: a retrospective study

OBJECTIVES

A number of complications exist with invasive mechanical ventilation and with the use of and withdrawal from prolonged ventilator support. The use of protocols that enable the systematic identification of patients eligible for an interruption in mechanical ventilation can significantly reduce the number of complications. This study describes the application of a weaning protocol and its results.

METHODS

Patients who required invasive mechanical ventilation for more than 24 hours were included and assessed daily to identify individuals who were ready to begin the weaning process.

RESULTS

We studied 252 patients with a median mechanical ventilation time of 3.7 days (interquartile range of 1 to 23 days), a rapid shallow breathing index value of 48 (median), a maximum inspiratory pressure of 40 cmH(2)0, and a maximum expiratory pressure of 40 cm H(2)0 (median). Of these 252 patients, 32 (12.7%) had to be reintubated, which represented weaning failure. Noninvasive ventilation was used postextubation in 170 (73%) patients, and 15% of these patients were reintubated, which also represented weaning failure. The mortality rate of the 252 patients studied was 8.73% (22), and there was no significant difference in the age, gender, mechanical ventilation time, and maximum inspiratory pressure between the survivors and nonsurvivors.

CONCLUSIONS

The use of a specific weaning protocol resulted in a lower mechanical ventilation time and an acceptable reintubation rate. This protocol can be used as a comparative index in hospitals to improve the weaning system, its monitoring and the informative reporting of patient outcomes and may represent a future tool and source of quality markers for patient care.

Aerosol therapy in patients receiving noninvasive positive pressure ventilation

In selected patients, noninvasive positive pressure ventilation (NIPPV) with a facemask is now commonly employed as the first choice for providing mechanical ventilation in the intensive care unit (ICU). Aerosol therapy for treatment of acute or acute-on-chronic respiratory failure in this setting may be delivered by pressurized metered-dose inhaler (pMDI) with a chamber spacer and facemask or nebulizer and facemask. This article reviews the host of factors influencing aerosol delivery with these devices during NIPPV. These factors include (1) the type of ventilator, (2) mode of ventilation, (3) circuit conditions, (4) type of interface, (5) type of aerosol generator, (6) drug-related factors, (7) breathing parameters, and (8) patient-related factors. Despite the impediments to efficient aerosol delivery because of continuous gas flow, high inspiratory flow rates, air leaks, circuit humidity, and patient-ventilator asynchrony, significant therapeutic effects are achieved after inhaled bronchodilator administration to patients with asthma and chronic obstructive pulmonary disease. Similarly to invasive mechanical ventilation, careful attention to the technique of drug administration is required to optimize therapeutic effects of inhaled therapies during NIPPV. Assessment of the patient's ability to tolerate a facemask, the level of respiratory distress, hemodynamic status, and synchronization of aerosol generation with inspiratory airflow are important factors contributing to the success of aerosol delivery during NIPPV. Further research into novel delivery methods, such as the use of NIPPV with nasal cannulae, could enhance the efficiency, ease of use, and reproducibility of inhalation therapy during noninvasive ventilation.

Comparisons of predictive performance of breathing pattern variability measured during T-piece, automatic tube compensation, and pressure support ventilation for weaning intensive care unit patients from mechanical ventilation

OBJECTIVE

To investigate the influence of different ventilatory supports on the predictive performance of breathing pattern variability for extubation outcomes in intensive care unit patients.

DESIGN AND SETTING

A prospective measurement of retrospectively analyzed breathing pattern variability in a medical center.

PATIENTS

Sixty-eight consecutive and ready-for-weaning patients were divided into success (n=45) and failure (n=23) groups based on their extubation outcomes.

MEASUREMENTS

Breath-to-breath analyses of peak inspiratory flow, total breath duration, tidal volume, and rapid shallow breathing index were performed for three 30-min periods while patients randomly received T-piece, 100% inspiratory automatic tube compensation with 5 cm H2O positive end-expiratory pressure, and 5 cm H2O pressure support ventilation with 5 cm H2O positive end-expiratory pressure trials. Coefficient of variations and data dispersion (standard descriptor values SD1 and SD2 of the Poincaré plot) were analyzed to serve as breathing pattern variability indices.

MAIN RESULTS

Under all three trials, breathing pattern variability in extubation failure patients was smaller than in extubation success patients. Compared to the T-piece trial, 100% inspiratory automatic tube compensation with 5 cm H2O positive end-expiratory pressure and 5 cm H2O pressure support ventilation with 5 cm H2O positive end-expiratory pressure decreased the ability of certain breathing pattern variability indices to discriminate extubation success from extubation failure. The areas under the receiver operating characteristic curve of these breathing pattern variability indices were: T-piece (0.73-0.87)>100% inspiratory automatic tube compensation with 5 cm H2O positive end-expiratory pressure (0.60-0.79)>5 cm H2O pressure support ventilation with 5 cm H2O positive end-expiratory pressure (0.53-0.76). Analysis of the classification and regression tree indicated that during the T-piece trial, a SD1 of peak inspiratory flow>3.36 L/min defined a group including all extubation success patients. Conversely, the combination of a SD1 of peak inspiratory flow ≤3.36 L/min and a coefficient of variations of rapid shallow breathing index ≤0.23 defined a group of all extubation failure patients. The decision strategies using SD1 of peak inspiratory flow and coefficient of variations of rapid shallow breathing index measured during 100% inspiratory automatic tube compensation with 5 cm H2O positive end-expiratory pressure and 5 cm H2O pressure support ventilation with 5 cm H2O positive end-expiratory pressure trials achieved a less clear separation of extubation failure from extubation success.

CONCLUSIONS

Since 100% inspiratory automatic tube compensation with 5 cm H2O positive end-expiratory pressure and 5 cm H2O pressure support ventilation with 5 cm H2O positive end-expiratory pressure reduce the predictive performance of breathing pattern variability, breathing pattern variability measurement during the T-piece trial is the best choice for predicting extubation outcome in intensive care unit patients patients.

[Evidence-based medicine: implications from the guideline "non-invasive ventilation" in critically ill elderly patients]

The demographic shift means that there are an increasing number of elderly critically ill patients with various comorbidities. This very specific group needs particular treatment which has not been considered sufficiently in medical guidelines so far. To improve health care, it is indispensable not only to work out the current guidelines, but aspects of geriatric medicine must also be integrated into future developments. Using the example of the recent guideline "non-invasive ventilation," it is shown how the process of designing and implication can actively be realized in clinical daily routine.

Noninvasive positive pressure ventilation as a weaning strategy for intubated adults with respiratory failure

BACKGROUND

Noninvasive positive pressure ventilation (NPPV) provides ventilatory support without the need for an invasive airway approach. Interest has emerged in using NPPV to facilitate earlier removal of an endotracheal tube and decrease complications associated with prolonged intubation.

OBJECTIVES

To summarize the evidence comparing NPPV and invasive positive pressure ventilation (IPPV) weaning on clinical outcomes in intubated adults with respiratory failure.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2008), MEDLINE (January 1966 to April 2008), EMBASE (January 1980 to April 2008), proceedings from four conferences, and personal files; and contacted authors to identify randomized controlled trials comparing NPPV and IPPV weaning.

SELECTION CRITERIA

Randomized and quasi-randomized studies comparing early extubation with immediate application of NPPV to IPPV weaning in intubated adults with respiratory failure.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and abstracted data according to prespecified criteria. Sensitivity and subgroup analyses were planned to assess the impact of (i) excluding quasi-randomized trials, and (ii) the etiology of respiratory failure on selected outcomes.

MAIN RESULTS

We identified 12 trials of moderate to good quality that involved 530 participants with predominantly chronic obstructive pulmonary disease (COPD). Compared to the IPPV strategy, NPPV significantly decreased mortality (relative risk (RR) 0.55, 95% confidence Interval (CI) 0.38 to 0.79), ventilator associated pneumonia (RR 0.29, 95% CI 0.19 to 0.45), length of stay in an intensive care unit (weighted mean difference (WMD) -6.27 days, 95% CI -8.77 to -3.78) and hospital (WMD -7.19 days, 95% CI -10.80 to -3.58), total duration of ventilation (WVD) -5.64 days (95% CI -9.50 to -1.77) and duration of endotracheal mechanical ventilation (WMD - 7.81 days, 95% CI -11.31 to -4.31). Noninvasive weaning had no effect on weaning failures or the duration of ventilation related to weaning. Excluding a single quasi-randomized trial maintained the significant reduction in mortality and ventilator associated pneumonia. Subgroup analyses suggested that the benefits on mortality and weaning failures were nonsignificantly greater in trials enrolling exclusively COPD patients versus mixed populations.

AUTHORS' CONCLUSIONS

Summary estimates from 12 small studies of moderate to good quality that included predominantly COPD patients demonstrated a consistent, positive effect on mortality and ventilator associated pneumonia. The net clinical benefits associated with noninvasive weaning remain to be fully elucidated.

Non-invasive ventilation in acute respiratory failure

Non-invasive mechanical ventilation has been increasingly used to avoid or serve as an alternative to intubation. Compared with medical therapy, and in some instances with invasive mechanical ventilation, it improves survival and reduces complications in selected patients with acute respiratory failure. The main indications are exacerbation of chronic obstructive pulmonary disease, cardiogenic pulmonary oedema, pulmonary infiltrates in immunocompromised patients, and weaning of previously intubated stable patients with chronic obstructive pulmonary disease. Furthermore, this technique can be used in postoperative patients or those with neurological diseases, to palliate symptoms in terminally ill patients, or to help with bronchoscopy; however further studies are needed in these situations before it can be regarded as first-line treatment. Non-invasive ventilation implemented as an alternative to intubation should be provided in an intensive care or high-dependency unit. When used to prevent intubation in otherwise stable patients it can be safely administered in an adequately staffed and monitored ward.

Use of non-invasive ventilation to wean critically ill adults off invasive ventilation: meta-analysis and systematic review

OBJECTIVE

To summarise the evidence for early extubation with immediate application of non-invasive ventilation compared with continued invasive weaning on important outcomes in intubated adults with respiratory failure.

DESIGN

Systematic review and meta-analysis of randomised and quasi-randomised controlled trials.

SETTING

Intensive care units.

PARTICIPANTS

Critically ill adults receiving invasive ventilation. Study selection criteria We searched Medline, Embase, and CENTRAL, proceedings from four conferences, and reference lists of relevant studies to identify relevant trials. Two reviewers independently selected trials, assessed trial quality, and abstracted data.

RESULTS

We identified 12 trials enrolling 530 participants, mostly with chronic obstructive pulmonary disease. Compared with invasive weaning, non-invasive weaning was significantly associated with reduced mortality (relative risk 0.55, 95% confidence interval 0.38 to 0.79), ventilator associated pneumonia (0.29, 95% 0.19 to 0.45), length of stay in intensive care unit (weighted mean difference -6.27 days, -8.77 to -3.78) and hospital (-7.19 days, -10.80 to -3.58), total duration of ventilation, and duration of invasive ventilation. Non-invasive weaning had no effect on weaning failures or weaning time. Benefits on mortality and weaning failures were non-significantly greater in trials that exclusively enrolled patients with chronic obstructive pulmonary disease versus mixed populations.

CONCLUSIONS

Current trials in critically ill adults show a consistent positive effect of non-invasive weaning on mortality and ventilator associated pneumonia, though the net clinical benefits remain to be fully elucidated. Non-invasive ventilation should preferentially be used in patients with chronic obstructive pulmonary disease in a highly monitored environment.