High-intensity Noninvasive Positive Pressure Ventilation Research Articles

Clinical efficacy of HI-NPPV in the treatment of AECOPD combined with severe type II respiratory failure.

Patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) combined with severe type II respiratory failure have a high probability of ventilation failure using conventional non-invasive positive pressure ventilation (NPPV). This study aims to investigate the clinical efficacy of high intensity NPPV (HI-NPPV) for the treatment of AECOPD combined with severe type II respiratory failure. The data of patients with AECOPD combined with severe type II respiratory failure (blood gas analysis pH≤7.25) treated with NPPV in the Second Affiliated Hospital of Chongqing Medical University from July 2013 to July 2023 were collected to conduct a retrospective case-control study. The patients were divided into 2 groups according to the inspired positive airway pressure (IPAP) used during the NPPV treatment: a NPPV group (IPAP<20 cmH2O, 1 cmH2O=0.098 kPa) and a HI-NPPV group (20 cmH2O≤IPAP< 30 cmH2O). Ninety-nine and 95 patients were included in the NPPV group and the HI-NPPV group, respectively. A total of 86 pairs of data were matched using propensity score matching (PSM) for data matching. The primary outcome indexes (mortality and tracheal intubation rate) and secondary outcome indexes [blood gas analysis pH, arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2), adverse reaction rate, and length of hospitalization] were compared between the 2 groups. The tracheal intubation rates of the NPPV group and the HI-NPPV group were 6.98% and 1.16%, respectively, and the difference between the 2 groups was statistically significant (χ2=4.32, P<0.05); the mortality of the NPPV group and the HI-NPPV group was 23.26% and 9.30%, respectively, and the difference between the 2 groups was statistically significant (χ2=11.64, P<0.01). The PaO2 at 24 h and 48 h after treatment of the HI-NPPV group was higher than that of the NPPV group, and the PaCO2 of the HI-NPPV group was lower than that of the NPPV group, and the differences were statistically significant (all P<0.05). The differences of pH at 24 h and 48 h after treatment between the 2 groups were not statistically significant (both P>0.05). The differences between the 2 groups in adverse reaction rate and hospitalization length were not statistically significant (both P>0.05). HI-NPPV can reduce mortality and tracheal intubation rates by rapidly improving the ventilation of patients with AECOPD combined with severe type II respiratory failure. This study provides a new idea for the treatment of patients with AECOPD combined with severe type II respiratory failure.

Comparison of High Intensity Non-Invasive Ventilation With Low Intensity Non-Invasive Ventilation In Patients With Acute Copd Exacerbation

Objective: To determine the outcome of high intensity non-invasive positive pressure ventilation (HI-NPPV) as compared to low intensity non-invasive positive pressure ventilation (LI-NPPV) in patients with acute COPD exacerbations. Methodology: This Randomized controlled trial Department of PulmonologyFauji Foundation Hospital Rawalpindi from  31st December 2016 to 30thJune 2017. Arterial blood gases will be taken at admission. If values of pH and paCO2 meet the criteria for non-invasive ventilation then patients will be enrolled in the study. Patients will be randomly divided into two groups by lottery method. GROUP A and GROUP B. GROUP A will receive high intensity NIV (HI-NPPV) and GROUP B will receive low intensity NIV (LI-NPPV) by TRIOLOGY machine. Expiratory positive airway pressure (EPAP) will remain between 4 to 6 cmH2O. Arterial blood gases (ABGs) will be done at baseline and then 72 hours after admission. Improvement in PaCO2, HCO3, and FEV1 will be recorded 72 hours from baseline and collected on proforma (attached). Results: Mean age (years) in the study was 55.54+3.81. There were 08 male patients included the study meeting the inclusion criteria. Of these, 05 and 03 male patients among both the groups respectively. Similarly, there were 92 female patients included the study meeting the inclusion criteria, of these, 45 and 47 female patients among both the groups respectively. Outcome of the study was assessed in terms of mean PaCO2 (mmHg), HCO3 (mmol/L) and FEV1 at baseline and after 72 hours. Mean PaCO2, HCO3 and FEV1 at baseline was 64.87+5.22, 33.75+4.17 and 0.66+0.04 respectively. After 72 hours, mean PaCO2 (mmHg) , HCO3(mmol/L), and FEV1 among both the groups was 63.98+6.58 vs 41.46+2.40, 33.10+4.81 vs 23.12+2.01, 0.66+0.05 vs 0.72+0.04 with following P value of (0,000, 0.000, 0.000) respectively. Conclusion: High intensity non-invasive positive pressure ventilation (HI-NPPV) has no different outcome as compared to low intensity non-invasive positive pressure ventilation (LI-NPPV) in patients with acute COPD exacerbations.

Physiological effects of high-intensity versus low-intensity noninvasive positive pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease: a randomised controlled trial

BackgroundHigh-intensity noninvasive positive pressure ventilation (NPPV) is a novel ventilatory approach to maximally decreasing elevated arterial carbon dioxide tension (PaCO2) toward normocapnia with stepwise up-titration of pressure support. We tested whether high-intensity NPPV is more effective than low-intensity NPPV at decreasing PaCO2, reducing inspiratory effort, alleviating dyspnoea, improving consciousness, and improving NPPV tolerance in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).MethodsIn this physiological, randomised controlled trial, we assigned 24 AECOPD patients to undergo either high-intensity NPPV (n = 12) or low-intensity NPPV (n = 12). The primary outcome was PaCO2 24 h after randomisation. Secondary outcomes included gas exchange other than PaCO2 24 h after randomisation, inspiratory effort, dyspnoea, consciousness, NPPV tolerance, patient–ventilator asynchrony, cardiac function, ventilator-induced lung injury (VILI), and NPPV-related adverse events.ResultsInspiratory positive airway pressure 24 h after randomisation was significantly higher (28.0 [26.0–28.0] vs. 15.5 [15.0–17.5] cmH2O; p = 0.000) and NPPV duration within the first 24 h was significantly longer (21.8 ± 2.1 vs. 15.3 ± 4.7 h; p = 0.001) in the high-intensity NPPV group. PaCO2 24 h after randomisation decreased to 54.0 ± 11.6 mmHg in the high-intensity NPPV group but only decreased to 67.4 ± 10.6 mmHg in the low-intensity NPPV group (p = 0.008). Inspiratory oesophageal pressure swing, oesophageal pressure–time product (PTPes)/breath, PTPes/min, and PTPes/L were significantly lower in the high-intensity group. Accessory muscle use and dyspnoea score 24 h after randomisation were also significantly lower in that group. No significant between-groups differences were observed in consciousness, NPPV tolerance, patient–ventilator asynchrony, cardiac function, VILI, or NPPV-related adverse events.ConclusionsHigh-intensity NPPV is more effective than low-intensity NPPV at decreasing elevated PaCO2, reducing inspiratory effort, and alleviating dyspnoea in AECOPD patients.Trial registration: ClinicalTrials.gov (NCT04044625; registered 5 August 2019).

Is bilevel PAP more effective than CPAP in treating hypercapnic obese patients with COPD and severe OSA?

Commentary on Zheng Y, Yee BJ, Wong K, Grunstein R, Piper A. A pilot randomized trial comparing CPAP versus bilevel PAP spontaneous mode in the treatment of hypoventilation disorder in patients with obesity and obstructive airway disease. J Clin Sleep Med. 20XX;XX(XX):XXX-XXX. doi:10.5664/jcsm.9506.

Noninvasive positive pressure ventilation in stable patients with COPD.

Long-term noninvasive positive pressure ventilation (NIV) used to be a controversial form of therapy for patients with stable hypercapnic chronic obstructive pulmonary disease (SH-COPD). New evidence described in this review defines the optimal settings, timing and target population for NIV utilization in SH-COPD necessary to maximize its benefit. NIV, when titrated appropriately, leads to improved clinical outcomes. High inspiratory positive airway pressures aimed at decreasing CO2 levels can ensure NIV success in SH-COPD. NIV initiated when patients remain hypercapnic whereas in a clinical stable state following an acute exacerbation can prolong the time to a readmission. Technological advances in NIV algorithms and remote monitoring have the potential to improve use and titration. NIV and portable NIV improve exercise tolerance and may accentuate the benefits derived from pulmonary rehabilitation alone. Use of high-intensity NIV in SH-COPD is beneficial yet appropriate patient selection and implementation is paramount.

Noninvasive Ventilation in Chronic Obstructive Pulmonary Disease.

The role of noninvasive positive pressure ventilation (NIV) in severe chronic obstructive pulmonary disease (COPD) has been controversial. Over the past two decades, data primarily obtained from Europe have begun to define the clinical characteristics of patients likely to respond, the role of high-intensity NIV, and the potential best timing of initiating therapy. These approaches, however, have not been validated in the context of the U.S. healthcare delivery system. Use of NIV in severe COPD in the United States is limited by the practicalities of doing in-hospital titrations as well as a complex system of reimbursement. These systematic complexities, coupled with a still-emerging clinical trial database regarding the most effective means to deliver NIV, have led to persistent uncertainty regarding when in stable severe COPD treatment with NIV is actually appropriate. In this review, we propose an assessment algorithm and treatment plan that can be used in clinical practice in the United States, but we acknowledge that the absence of pivotal clinical trials largely precludes a robust evidence-based approach to this potentially valuable therapy.

Effects of High-intensity Noninvasive Positive Pressure Ventilation in AECOPD

Effects of High-intensity Noninvasive Positive Pressure Ventilation in AECOPD

High-intensity versus low-intensity noninvasive positive pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease (HAPPEN): study protocol for a multicenter randomized controlled trial

BackgroundDespite the positive outcomes of the use of noninvasive positive pressure ventilation (NPPV) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), NPPV fails in approximately 15% of patients with AECOPD, possibly because the inspiratory pressure delivered by conventional low-intensity NPPV is insufficient to improve ventilatory status for these patients. High-intensity NPPV, a novel form that delivers high inspiratory pressure, is believed to more efficiently augment alveolar ventilation than low-intensity NPPV, and it has been shown to improve ventilatory status more than low-intensity NPPV in stable AECOPD patients. Whether the application of high-intensity NPPV has therapeutic advantages over low-intensity NPPV in patients with AECOPD remains to be determined. The high-intensity versus low-intensity NPPV in patients with AECOPD (HAPPEN) study will examine whether high-intensity NPPV is more effective for correcting hypercapnia than low-intensity NPPV, hence reducing the need for intubation and improving survival.Methods/designThe HAPPEN study is a multicenter, two-arm, single-blind, prospective, randomized controlled trial. In total, 600 AECOPD patients with low to moderate hypercapnic respiratory failure will be included and randomized to receive high-intensity or low-intensity NPPV, with randomization stratified by study center. The primary endpoint is NPPV failure rate, defined as the need for endotracheal intubation and invasive ventilation. Secondary endpoints include the decrement of arterial carbon dioxide tension from baseline to 2 h after randomization, in-hospital and 28-day mortality, and 90-day survival. Patients will be followed up for 90 days after randomization.DiscussionThe HAPPEN study will be the first randomized controlled study to investigate whether high-intensity NPPV better corrects hypercapnia and reduces the need for intubation and mortality in AECOPD patients than low-intensity NPPV. The results will help critical care physicians decide the intensity of NPPV delivery to patients with AECOPD.Trial registrationClinicalTrials.gov, NCT02985918. Registered on 7 December 2016.

High Intensity Non-Invasive Positive Pressure Ventilation (HINPPV) for Stable Hypercapnic Chronic Obstructive Pulmonary Disease (COPD) Patients.

Introduction: High intensity non-invasive positive pressure ventilation (HI-NPPV) is an algorithm of non-invasive ventilation that has been shown to improve partial pressure of carbon dioxide (PaCO2), health-related quality of life and mortality in hypercapnic chronic obstructive pulmonary disease (COPD) patients. Objective: Assess 3 months of HI-NPPV in stable hypercapnic COPD patients. Methods: A single arm, non-randomized pilot study of HI-NPPV. Patients were eligible if they had clinically stable COPD and daytime arterial PaCO2 >50 mmHg. Results: Nine patients completed therapy. Patient characteristics: 2 male: 7 female, mean age of 64.4 years (SD ±6.6), mean forced expiratory volume in 1 second (FEV1) of 26% (SD±6.73), 8 patients on long term oxygen therapy (LTOT) and a median body mass index (BMI) of 26.6 (interquartile range [IQR] 25.5 - 32.5). Outcomes: There was a mean reduction in daytime PaCO2 by 4.66 mmHg (p=0.01) and bicarbonate by 2.16 mmHg (p=0.005). There was no statistically significant difference in lung function, maximal inspiratory pressures or 6 minute walk distance. There was no statistically significant difference in sleep duration, efficiency or percentage of sleep stage 3 ( N3) or rapid eye movement (REM). The Chronic Respiratory Questionnaire (CRQ) showed a trend towards improvement with an increase of 2.69 points (p=0.054), the dyspnea domain showed a statistically significant improvement (p=0.03). The Calgary Sleep Apnea Quality of Life Index (SAQLI) detected an improvement in daily functioning (p=0.007). The Severe Respiratory Insufficiency (SRI) Questionnaire showed a trend to improvement overall (p=0.05). Four patients had COPD exacerbations during the follow up period. Conclusions: HI-NPPV is able to substantially reduce PaCO2 in hypercapnic COPD patients; we detected a positive effect on quality of life measures with no significant change in sleep quality.

High Intensity Positive Pressure Ventilation and Long Term Pulmonary Function Responses in Severe Stable COPD. A Delicate and Difficult Balance

Method to improve minute ventilation (MV) during spontaneous breathing (SB) in stable severe chronic obstructive pulmonary disease (COPD) have a great clinical relevant in long term outcome. In this scenario, recommendations of early use of high-Intensity non-invasive Positive pressure Ventilation (HI-NPPV) or intelligent Volume Assured Pressure (iVAP) Support in Hypercapnic COPD have been proposed by safe therapeutics options. We analyze in this letter, Ekkernkamp et al. study that described the effect of HI-NPPV compared with SB on MV in patients receiving long-term treatment. We consider that interpretation of relationships between ABG, functional parameters, and respiratory mechanics reported need clarifications. Further prospective large clinical trials identifying the best mode of ventilation according to the characteristics in severe stable COPD are necessary to balance an effective approach and response on clinical symptoms and long-term effects.

Minute Ventilation During Spontaneous Breathing, High-Intensity Noninvasive Positive Pressure Ventilation and Intelligent Volume Assured Pressure Support in Hypercapnic COPD

Background: High-intensity noninvasive positive pressure ventilation (HI-NPPV) is an effective treatment option in patients with stable hypercapnic chronic obstructive pulmonary disease (COPD). However, the effect of HI-NPPV compared with spontaneous breathing (SB) on minute ventilation (MV) in patients receiving long-term treatment remains to be determined. This study compared MV during HI-NPPV and SB. In addition, the ability of intelligent volume assured pressure support (iVAPS) to increase MV to the same extent as HI-NPPV was determined. Methods: Daytime pneumotachographic measurements were performed during SB, HI-NPPV and iVAPS. Results: Twenty-seven stable hypercapnic COPD patients (mean FEV1 34 ± 15% predicted) who had been treated with HI-NPPV for a median of 22 months (interquartile range 8.5–84 months) were enrolled. Mean MV was 9.5 ± 1.7 L/min during SB and 12.1 ± 2.8 L/min during HI-NPPV, an increase of 2.5 L/min (95% CI [1.5–3.6] p < 0.001), or 26%. MV during iVAPS was 11.7 ± 3.6 L/min, an increase of 1.8 L/min (95%CI [0.7–3.0], p = 0.003) compared with SB. There was no difference in MV between HI-NPPV and iVAPS (p = 0.25). Conclusion: Long-term HI-NPPV increased MV by an average of 26% compared with SB in stable hypercapnic COPD patients. A similar increase in MV was observed during use of iVAPS.

Noninvasive positive pressure ventilation in COPD

Educational aims To take up the ongoing debate on whether long-term noninvasive positive pressure ventilation (NPPV) should be applied in chronic obstructive pulmonary disease (COPD) patients with chronic hypercapnic respiratory failure. To elucidate the impact of NPPV techniques on NPPV success in COPD. To describe the technique and scientific evidence for the new concept of high-intensity NPPV. To provide practical considerations on how to commence high-intensity NPPV. To outline important unknowns regarding long-term NPPV in COPD patients. Summary Home mechanical ventilation, as provided by long-term NPPV, is a widely accepted treatment option for many patient groups with chronic hypercapnic respiratory failure, including also those with COPD, even though the rationale for long-term NPPV in COPD patients is still disputed. This is based on clinical observations that conventional NPPV using assisted ventilation and low mean inspiratory pressures of Recently, however, a promising technique of NPPV has been described, which aims at maximally improving gas exchange by the use of controlled ventilation and considerably higher inspiratory pressures, typically ranging 20–40 cmH2O. This is known as high-intensity NPPV. This approach clearly contrasts with the conventional, low-intensity approach. High-intensity NPPV has been shown to improve physiological parameters such as breathing pattern, gas exchange and lung function. In addition, it also provides clinical benefits, with improvements in dyspnoea, walking distance and specific aspects of health-related quality of life. The superiority of high- over low-intensity NPPV has been clearly established by randomised crossover trials. Increasing evidence now exists to support the contention that long-term high-intensity NPPV offers a new therapeutic option in the treatment of hypercapnic COPD. However, the questions of whether high-intensity NPPV is also capable of improving survival and how to best select candidates to undergo long-term high-intensity NPPV remain pressing. This article also provides detailed practical descriptions of how to initiate high-intensity NPPV.

Noninvasive Ventilation in COPD: Impact of Inspiratory Pressure Levels on Sleep Quality

Although high-intensity noninvasive positive pressure ventilation (HI-NPPV) is superior to low-intensity noninvasive positive pressure ventilation (LI-NPPV) in controlling nocturnal hypoventilation in stable hypercapnic patients with COPD, it produces higher amounts of air leakage, which, in turn, could impair sleep quality. Therefore, the present study assessed the difference in sleep quality during HI-NPPV and LI-NPPV. A randomized, controlled, crossover trial comparing sleep quality during HI-NPPV (mean inspiratory positive airway pressure 29 ± 4 mbar) and LI-NPPV (mean inspiratory positive airway pressure 14 mbar) was performed in 17 stable hypercapnic patients with COPD who were already familiar with HI-NPPV. Thirteen patients (mean FEV(1) 27% ± 11% predicted) completed the trial; four patients refused to sleep under LI-NPPV. There was no significant difference in sleep quality between the treatment groups (all P > .05), with a mean difference of -3.0% (95% CI, -10.0 to 3.9; P = .36) in the primary outcome, namely non-rapid eye movement sleep stages 3 and 4. However, nocturnal Paco(2) was lower during HI-NPPV compared with LI-NPPV, with a mean difference of -6.4 mm Hg (95% CI, -10.9 to -1.8; P = .01). In patients with COPD, high inspiratory pressures used with long-term HI-NPPV produce acceptable sleep quality that is no worse than that produced by lower inspiratory pressures, which are more traditionally applied in conjunction with LI-NPPV. In addition, higher pressures are more successful in maintaining sufficient alveolar ventilation compared with low pressures. Thus, HI-NPPV is a very promising new approach, but still requires large, longer-term trials to determine the impact on outcomes such as exacerbation rates and longevity. German Clinical Trials Register (DRKS); No.: DRKS00000520; URL: www.drks.de.

High-intensity versus low-intensity non-invasive ventilation in patients with stable hypercapnic COPD: a randomised crossover trial

RationaleThe conventional approach of low-intensity non-invasive positive pressure ventilation (NPPV) produces only minimal physiological and clinical benefits in patients with stable hypercapnic chronic obstructive pulmonary disease (COPD).ObjectivesTo determine whether the...

High-intensity non-invasive positive pressure ventilation for stable hypercapnic COPD

The objective of the present analysis is to describe the outcomes of high-intensity non-invasive positive pressure ventilation (NPPV) aimed at maximally decreasing PaCO(2) as an alternative to conventional NPPV with lower ventilator settings in stable hypercapnic COPD patients. Physiological parameters, exacerbation rates and long-term survival were assessed in 73 COPD patients (mean FEV(1) 30+/-12 %predicted) who were established on high-intensity NPPV due to chronic hypercapnic respiratory failure between March 1997 and May 2006. Controlled NPPV with breathing frequencies of 21+/-3 breath/min and mean inspiratory/expiratory positive airway pressures of 28+/-5/5+/-1 cmH(2)O led to significant improvements in blood gases, lung function and hematocrit after two months. Only sixteen patients (22%) required hospitalisation due to exacerbation during the first year, with anaemia increasing the risk for exacerbation. Two- and five-year survival rates of all patients were 82% and 58%, respectively. The five year survival rate was 32% and 83% in patients with low (< or =39%) and high (> or =55%) hematocrit, respectively. High-intensity NPPV improves blood gases, lung function and hematocrit, and is also associated with low exacerbation rates and a favourable long-term outcome. The current report strongly emphasises the need for randomised controlled trials evaluating the role of high-intensity NPPV in stable hypercapnic COPD patients.

Noninvasive ventilation during walking in patients with severe COPD: a randomised cross-over trial

It was hypothesised that noninvasive positive-pressure ventilation (NPPV) applied during walking prevents exercise-induced hypoxaemia and improves exercise performance in severe chronic obstructive pulmonary disease (COPD) patients already receiving long-term NPPV. A total of 20 COPD patients (mean+/-sd age 65.1+/-8.7 yrs, forced expiratory volume in one second 27+/-8% predicted and total lung capacity 116+/-27% pred) reporting dyspnoea, even during mild exertion, underwent two 6-min walking tests with a rollator and supplemental oxygen (2.1+/-0.9 L.min(-1)) in a randomised cross-over design: with and without pressure-limited NPPV as used at home (inspiratory:expiratory pressure 2.9+/-0.44:0.4+/-0.1 kPa (29+/-4:4+/-1 mbar), respiratory frequency 20+/-2 breaths.min(-1)). The arterial oxygen tension significantly increased by 1.39+/-1.43 kPa (95% confidence interval (CI) 0.71-2.07 kPa) after walking with NPPV, but significantly decreased by 1.43+/-1.06 kPa (95% CI -1.92 - -0.94 kPa) without NPPV. Dyspnoea, as assessed by the Borg dyspnoea scale, significantly decreased from 6 (interquartile range (IQR) 4.5-10) to 4 (1.5-4.5) and walking distance significantly increased from 209 (IQR 178-279) to 252 (203-314) m when walking was NPPV-aided. In chronic hypercapnic chronic obstructive pulmonary disease, high-intensity noninvasive positive-pressure ventilation can also be administered during walking with unchanged ventilator settings compared with settings used at rest, thus resulting in improved oxygenation, decreased dyspnoea and increased walking distance. Therefore, noninvasive positive-pressure ventilation during walking could prevent hypoxia-induced complications and could, in future, play a role in palliative care.

Outcome of Patients With Stable COPD Receiving Controlled Noninvasive Positive Pressure Ventilation Aimed at a Maximal Reduction of Paco2

The role of noninvasive positive pressure ventilation (NPPV) has been well established in the treatment of acute hypercapnic respiratory failure due to COPD. However, evidence for a sustained improvement in blood gas levels and survival in patients with stable hypercapnic COPD following NPPV is still lacking. There is concern that this might be due to low inspiratory pressures of < 18 cm H2O used in previous studies, which thereby did not achieve a reduction of Pa(CO2). Therefore, the 2-year survival and changes in lung function and blood gas levels were analyzed in patients with stable hypercapnic COPD in whom controlled pressure-limited NPPV was titrated to achieve a maximal improvement in Pa(CO2). Retrospective study between March 1997 and September 2003. General ward of a university hospital. Thirty-four consecutive patients with stable (mean pH 7.40 +/- 0.03) hypercapnic COPD (mean age, 63.4 +/- 9.7 years [+/- SD]; mean body mass index, 28.3 +/- 7.3 kg/m2). Daytime Pa(CO2) during spontaneous breathing decreased by 6.9 +/- 8.0 (95% confidence interval, - 9.9 to - 3.9), from 53.3 +/- 4.8 to 46.4 +/- 7.0 mm Hg (p < 0.001); while daytime Pa(O2) increased by 5.8 +/- 9.4 (95% confidence interval, 2.3 to 9.3), from 51.7 +/- 8.8 to 57.5 +/- 9.3 mm Hg (p = 0.002); and FEV1 increased by 0.14 +/- 0.16 (95% confidence interval, 0.08 to 0.20), from 1.03 +/- 0.54 to 1.17 +/- 0.59 L (p < 0.001) after 2 months of NPPV. This was achieved with mean inspiratory pressures of 27.7 +/- 5.9 cm H2O (range, 17 to 40 cm H2O) at a mean respiratory rate of 20.8 +/- 2.5 breaths/min (range, 14 to 24 breaths/min). The 2-year survival rate was 86%. Controlled NPPV using a mean inspiratory pressure of 28 cm H2O is well tolerated over longer periods and can improve blood gas levels and lung function. Prospective, randomized controlled trials of high-intensity NPPV are required to evaluate its role in patients with stable hypercapnic COPD.