Physiological effects and optimisation of nasal assist-control ventilation for patients with chronic obstructive pulmonary disease in respiratory failure

Non-invasive ventilation in the care of patients with chronic obstructive pulmonary disease with palliative care needs: a scoping review

BACKGROUND

Patients with severe chronic obstructive pulmonary disease (COPD) could have palliative care (PC) needs because of unmet needs such as dyspnoea. This may lead to anxiety and may have an impact on patients' ability to perform daily activities of living. PC can be started when patients with COPD have unmet needs and can be provided alongside disease-modifying therapies. Non-invasive ventilation (NIV) could be an important measure to manage dyspnoea in patients with COPD in need of PC. A scoping review was conducted to gain an overview of the existing research and to identify knowledge gaps. The aim of this scoping review was to systematically map published studies on the use of NIV in patients with COPD with PC needs, including the perspectives and experiences of patients, families, and healthcare professionals (HCPs).

METHODS

This review was conducted following the framework of Arksey and O'Malley. The reporting of the review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews checklist. The review protocol was published. AMED, CINAHL, Embase, MEDLINE, PEDro, and PsycInfo were searched from inception to November 14, 2022. The included studies had to report the perspectives and experiences of COPD patients, relatives, and HCPs regarding NIV in the care of patients with COPD with PC needs. In pairs, the authors independently assessed studies' eligibility and extracted data. The data were organised thematically. The results were discussed in a consultation exercise.

RESULTS

This review included 33 papers from 32 studies. Four thematic groupings were identified: preferences and attitudes towards the use of NIV; patient participation in the decision-making process of NIV treatment; conflicting results on the perceived benefits and burdens of treatment; and heterogenous clinical outcomes in experimental studies. Patients perceived NIV as a 'life buoy' to keep them alive. Many patients wanted to take part in the decision-making process regarding NIV treatment but expressed varying degrees of inclusion by HCPs in such decision-making. Conflicting findings were identified regarding the perceived benefits and burdens of NIV treatment. Diversity in heterogeneous clinical outcomes were reported in experimental studies.

CONCLUSIONS

There is a need for more studies designed to investigate the effectiveness of NIV as a palliative measure for patients with COPD with PC needs using comprehensive outcomes. It is especially important to gain more knowledge on the experiences of all stakeholders in the use of home-based NIV treatment to these patients.

Non-invasive ventilation for the management of acute hypercapnic respiratory failure due to exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Non-invasive ventilation (NIV) with bi-level positive airway pressure (BiPAP) is commonly used to treat patients admitted to hospital with acute hypercapnic respiratory failure (AHRF) secondary to an acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

OBJECTIVES

To compare the efficacy of NIV applied in conjunction with usual care versus usual care involving no mechanical ventilation alone in adults with AHRF due to AECOPD. The aim of this review is to update the evidence base with the goals of supporting clinical practice and providing recommendations for future evaluation and research.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register of trials (CAGR), which is derived from systematic searches of bibliographic databases including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Allied and Complementary Medicine Database (AMED), and PsycINFO, and through handsearching of respiratory journals and meeting abstracts. This update to the original review incorporates the results of database searches up to January 2017.

SELECTION CRITERIA

All randomised controlled trials that compared usual care plus NIV (BiPAP) versus usual care alone in an acute hospital setting for patients with AECOPD due to AHRF were eligible for inclusion. AHRF was defined by a mean admission pH < 7.35 and mean partial pressure of carbon dioxide (PaCO2) > 45 mmHg (6 kPa). Primary review outcomes were mortality during hospital admission and need for endotracheal intubation. Secondary outcomes included hospital length of stay, treatment intolerance, complications, changes in symptoms, and changes in arterial blood gases.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the selection criteria to determine study eligibility, performed data extraction, and determined risk of bias in accordance with Cochrane guidelines. Review authors undertook meta-analysis for data that were both clinically and statistically homogenous, and analysed data as both one overall pooled sample and according to two predefined subgroups related to exacerbation severity (admission pH between 7.35 and 7.30 vs below 7.30) and NIV treatment setting (intensive care unit-based vs ward-based). We reported results for mortality, need for endotracheal intubation, and hospital length of stay in a 'Summary of findings' table and rated their quality in accordance with GRADE criteria.

MAIN RESULTS

We included in the review 17 randomised controlled trials involving 1264 participants. Available data indicate that mean age at recruitment was 66.8 years (range 57.7 to 70.5 years) and that most participants (65%) were male. Most studies (12/17) were at risk of performance bias, and for most (14/17), the risk of detection bias was uncertain. These risks may have affected subjective patient-reported outcome measures (e.g. dyspnoea) and secondary review outcomes, respectively.Use of NIV decreased the risk of mortality by 46% (risk ratio (RR) 0.54, 95% confidence interval (CI) 0.38 to 0.76; N = 12 studies; number needed to treat for an additional beneficial outcome (NNTB) 12, 95% CI 9 to 23) and decreased the risk of needing endotracheal intubation by 65% (RR 0.36, 95% CI 0.28 to 0.46; N = 17 studies; NNTB 5, 95% CI 5 to 6). We graded both outcomes as 'moderate' quality owing to uncertainty regarding risk of bias for several studies. Inspection of the funnel plot related to need for endotracheal intubation raised the possibility of some publication bias pertaining to this outcome. NIV use was also associated with reduced length of hospital stay (mean difference (MD) -3.39 days, 95% CI -5.93 to -0.85; N = 10 studies), reduced incidence of complications (unrelated to NIV) (RR 0.26, 95% CI 0.13 to 0.53; N = 2 studies), and improvement in pH (MD 0.05, 95% CI 0.02 to 0.07; N = 8 studies) and in partial pressure of oxygen (PaO2) (MD 7.47 mmHg, 95% CI 0.78 to 14.16 mmHg; N = 8 studies) at one hour. A trend towards improvement in PaCO2 was observed, but this finding was not statistically significant (MD -4.62 mmHg, 95% CI -11.05 to 1.80 mmHg; N = 8 studies). Post hoc analysis revealed that this lack of benefit was due to the fact that data from two studies at high risk of bias showed baseline imbalance for this outcome (worse in the NIV group than in the usual care group). Sensitivity analysis revealed that exclusion of these two studies resulted in a statistically significant positive effect of NIV on PaCO2. Treatment intolerance was significantly greater in the NIV group than in the usual care group (risk difference (RD) 0.11, 95% CI 0.04 to 0.17; N = 6 studies). Results of analysis showed a non-significant trend towards reduction in dyspnoea with NIV compared with usual care (standardised mean difference (SMD) -0.16, 95% CI -0.34 to 0.02; N = 4 studies). Subgroup analyses revealed no significant between-group differences.

AUTHORS' CONCLUSIONS

Data from good quality randomised controlled trials show that NIV is beneficial as a first-line intervention in conjunction with usual care for reducing the likelihood of mortality and endotracheal intubation in patients admitted with acute hypercapnic respiratory failure secondary to an acute exacerbation of chronic obstructive pulmonary disease (COPD). The magnitude of benefit for these outcomes appears similar for patients with acidosis of a mild (pH 7.30 to 7.35) versus a more severe nature (pH < 7.30), and when NIV is applied within the intensive care unit (ICU) or ward setting.

Weaning of mechanically ventilated chronic obstructive pulmonary disease patients by using non-invasive positive pressure ventilation: A prospective study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) patients frequently pose difficulty in weaning from invasive mechanical ventilation (MV). Prolonged invasive ventilation brings along various complications. Non-invasive positive pressure ventilation (NIPPV) is proposed to be a useful weaning modality in such cases.

OBJECTIVE

To evaluate the usefulness of NIPPV in weaning COPD patients from invasive MV, and compare it with weaning by conventional pressure support ventilation (PSV).

MATERIALS AND METHODS

For this prospective randomized controlled study, we included 50 COPD patients with type II respiratory failure requiring initial invasive MV. Upon satisfying weaning criteria and failing a t-piece weaning trial, they were randomized into two groups: Group I (25 patients) weaned by NIPPV, and group II (25 patients) weaned by conventional PSV. The groups were similar in terms of disease severity, demographic, clinical and biochemical parameters. They were compared in terms of duration of MV, weaning duration, length of intensive care unit (ICU) stay, occurrence of nosocomial pneumonia and outcome.

RESULTS

Statistically significant difference was found between the two groups in terms of duration of MV, weaning duration, length of ICU stay, occurrence of nosocomial pneumonia and outcome.

CONCLUSION

NIPPV appears to be a promising weaning modality for mechanically ventilated COPD patients and should be tried in resource-limited settings especially in developing countries.

Role of noninvasive ventilation in weaning from mechanical ventilation in patients of chronic obstructive pulmonary disease: an Indian experience

BACKGROUND

Endotracheal intubation and mechanical ventilation (MV) are often needed in patients of chronic obstructive pulmonary disease (COPD) with acute hypercapnic respiratory failure. The rate of weaning failure is high and prolonged MV increases intubation associated complications.

OBJECTIVE

To evaluate the role of Noninvasive ventilation (NIV) in weaning patients of chronic obstructive pulmonary disease (COPD) from MV, after T piece trial failure.

DESIGN

A prospective, randomized, controlled study was conducted in a tertiary care centre. 30 patients of acute exacerbation of COPD with acute on chronic hypercapnic respiratory failure, who were mechanically ventilated, were included in the study A T-piece weaning trial was attempted once the patients achieved satisfactory clinical and biochemical parameters. After T-piece failure, defined as pH < 7.35, PaCO(2) >50 mmHg, PaO(2) <50 mmHg, HR >100/min, RR >35, patients were randomized to receive either NIV or PSV.

RESULTS

Demography, severity of disease and clinical profiles were similar in both groups. No significant difference between the two groups in duration of MV (6.20 +/- 5.20 days vs. 7.47 +/- 6.38 days, P > 0.05), duration of weaning (35.17 +/- 16.98 and 47.05 +/- 20.98 hours, P > 0.05) or duration of ICU stay (8.47 +/- 4.79 and 10.80 +/- 5.28 days, P > 0.05) in Gp I and Gp II, respectively. Five patients developed VAP in the PSV group, where as only one patient had pneumonia in the NIV group. Lesser number of deaths in the NIV group at discharge from ICU (3 vs. 5 patients, respectively) and at 30 days (5 vs. 9 patients, respectively), it did not achieve statistical significance (P > 0.05).

CONCLUSION

NIV is as useful as PSV in weaning and can be better in weaning failure especially in COPD for earlier weaning, decrease ICU stay, complications and mortality.

Non-invasive positive pressure ventilation for treatment of respiratory failure due to exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Non-invasive positive pressure ventilation (NPPV) is being used increasingly in the management of patients admitted to hospital with acute respiratory failure secondary to an exacerbation of chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To determine the efficacy of NPPV in the management of patients with respiratory failure due to an acute exacerbation of COPD.

SEARCH STRATEGY

An initial search was performed using the Cochrane Airways Group trials register and other relevant electronic databases. An updated search was conducted in September 2003 and another in April 2004.

SELECTION CRITERIA

Randomised controlled trials comparing NPPV plus usual medical care (UMC) versus UMC alone were selected. Trials needed to recruit adult patients admitted to hospital with respiratory failure due to an exacerbation of COPD and with PaCO2 > 6 kPa (45 mmHg).

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected articles for inclusion, evaluated methodological quality of the studies and abstracted the data.

MAIN RESULTS

Fourteen studies were included in the review. NPPV resulted in decreased mortality (Relative Risk 0.52; 95%CI 0.35 to 0.76), decreased need for intubation (RR 0.41; 95%CI 0.33 to 0.53), reduction in treatment failure (RR 0.48; 95%CI 0.37 to 0.63), rapid improvement within the first hour in pH (Weight Mean Difference 0.03; 95%CI 0.02 to 0.04), PaCO2 (WMD -0.40 kPa; 95%CI -0.78 to -0.03) and respiratory rate (WMD -3.08 bpm; 95%CI -4.26 to -1.89). In addition, complications associated with treatment (RR 0.38; 95%CI 0.24 to 0.60) and length of hospital stay (WMD -3.24 days; 95%CI -4.42 to -2.06) was also reduced in the NPPV group.

REVIEWERS' CONCLUSIONS

Data from good quality randomised controlled trials show benefit of NPPV as first line intervention as an adjunct therapy to usual medical care in all suitable patients for the management of respiratory failure secondary to an acute exacerbation of COPD. NPPV should be considered early in the course of respiratory failure and before severe acidosis ensues, as a means of reducing the likelihood of endotracheal intubation, treatment failure and mortality.

Non-invasive positive pressure ventilation for treatment of respiratory failure due to exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Non-invasive positive pressure ventilation (NPPV) is being used increasingly in the management of patients admitted to hospital with acute respiratory failure secondary to an exacerbation of chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To determine the efficacy of NPPV in the management of patients with respiratory failure due to an acute exacerbation of COPD.

SEARCH STRATEGY

An initial search was performed using the Cochrane Airways Group trials register and other relevant electronic databases. An updated search was conducted in September 2003.

SELECTION CRITERIA

Randomised controlled trials comparing NPPV plus usual medical care (UMC) versus UMC alone were selected. Trials needed to recruit adult patients admitted to hospital with respiratory failure due to an exacerbation of COPD and with PaCO(2) > 6 kPa (45 mmHg).

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected articles for inclusion, evaluated methodological quality of the studies and abstracted the data.

MAIN RESULTS

Fourteen studies were included in the review. NPPV resulted in decreased mortality (Relative Risk 0.52; 95%CI 0.35, 0.76), decreased need for intubation (RR 0.41; 95%CI 0.33, 0.53), reduction in treatment failure (RR 0.48; 95%CI 0.37, 0.63), rapid improvement within the first hour in pH (Weight Mean Difference 0.03; 95%CI 0.02, 0.04), PaCO(2) (WMD -0.40 kPa; 95%CI -0.78, -0.03) and respiratory rate (WMD -3.08 bpm; 95%CI -4.26, -1.89). In addition, complications associated with treatment (RR 0.38; 95%CI 0.24, 0.60) and length of hospital stay (WMD -3.24 days; 95%CI -4.42, -2.06) was also reduced in the NPPV group.

REVIEWER'S CONCLUSIONS

Data from good quality randomised controlled trials show benefit of NPPV as first line intervention as an adjunct therapy to usual medical care in all suitable patients for the management of respiratory failure secondary to an acute exacerbation of COPD. NPPV should be considered early in the course of respiratory failure and before severe acidosis ensues, as a means of reducing the likelihood of endotracheal intubation, treatment failure and mortality.

Acute exacerbations of chronic obstructive pulmonary disease

This article discusses the definition, pathophysiology, cause, clinical presentation, laboratory work-up, and treatment of chronic obstructive pulmonary disease (COPD) exacerbation. The focus is on the presentation of acute exacerbations of COPD in the emergency department and the available evidence for testing and treatment.

Management of acute exacerbations of COPD: a summary and appraisal of published evidence

STUDY OBJECTIVES

To critically review the available data on the diagnostic evaluation, risk stratification, and therapeutic management of patients with acute exacerbations of COPD.

DESIGN, SETTING, AND PARTICIPANTS

English-language articles were identified from the following databases: MEDLINE (from 1966 to week 5, 2000), EMBASE (from 1974 to week 18, 2000), HealthStar (from 1975 to June 2000), and the Cochrane Controlled Trials Register (2000, issue 1). The best available evidence on each subtopic then was selected for analysis. Randomized trials, sometimes buttressed by cohort studies, were used to evaluate therapeutic interventions. Cohort studies were used to evaluate diagnostic tests and risk stratification. Study design and results were summarized in evidence tables. Individual studies were rated as to their internal validity, external validity, and quality of study design. Statistical analyses of combined data were not performed.

MEASUREMENT AND RESULTS

Limited data exist regarding the utility of most diagnostic tests. However, chest radiography and arterial blood gas sampling appear to be useful, while short-term spirometry measurements do not. In terms of the risk of relapse and the risk of death after hospitalization for an acute exacerbation, there are identifiable clinical variables that are associated with these outcomes. Therapies for which there is evidence of efficacy include bronchodilators, corticosteroids, and noninvasive positive-pressure ventilation. There is also support for the use of antibiotics in patients with more severe exacerbations. Based on limited data, mucolytics and chest physiotherapy do not appear to be of benefit, and oxygen supplementation appears to increase the risk of respiratory failure in an identifiable subgroup of patients.

CONCLUSIONS

Although suggestions for appropriate management can be made based on available evidence, the supporting literature is spotty. Further high-quality research is needed and will require an improved, generally acceptable, and transportable definition of the syndrome "acute exacerbation of COPD" and improved methods for observing and measuring outcomes.

Noninvasive ventilation as a systematic extubation and weaning technique in acute-on-chronic respiratory failure: a prospective, randomized controlled study

Prolonged duration of endotracheal mechanical ventilation (ETMV) is associated with an increased morbidity and mortality in intensive care unit (ICU) patients. The aim of this study was to assess the usefulness of noninvasive ventilation (NIV) as a systematic extubation and weaning technique to reduce the duration of ETMV in acute-on-chronic respiratory failure (ACRF). Among 53 consecutively intubated patients admitted for ACRF, we conducted a prospective, randomized controlled trial of weaning in 33 patients who failed a 2-h T-piece weaning trial (2 h-WT) although they met simple criteria for weaning. Conventional invasive pressure support ventilation (IPSV) was used as the control weaning technique in 16 patients (IPSV group), and NIV was applied immediately after extubation in 17 patients (NIV group). The two weaning groups were similar for type of chronic respiratory failure (CRF), pulmonary function data, age, Simplified Acute Physiology Score (SAPS II), and severity of ACRF on admission. The characteristics of the two groups were also similar at randomization. In the IPSV group, 12 of 16 patients (75%) were successfully weaned and extubated, versus 13 of 17 (76.5%) in the NIV group (p = NS). NIV like IPSV significantly and similarly improved gas exchange in relation to that achieved during 2 h-WT (p < 0.05). The duration of ETMV was significantly shorter in the NIV (4.56 +/- 1.85 d) than in the IPSV group (7.69 +/- 3.79 d) (p = 0. 004). NIV also reduced the mean period of daily ventilatory support, but increased the total duration of ventilatory support related to weaning (3.46 +/- 1.42 d, versus 11.54 +/- 5.24 d with NIV; p = 0. 0001). Most patients in the IPSV group developed complications related to ETMV and/or the weaning process, but the difference was not significant (nine of 16 versus six of 17). The durations of ICU and hospital stays and the 3-mo survival were similar in the two groups. In conclusion, NIV permits earlier removal of the endotracheal tube than with conventional IPSV, and reduces the duration of daily ventilatory support without increasing the risk of weaning failures. NIV should be considered as a new and useful systematic approach to weaning in patients with ACRF who are difficult to wean.