The importance of stabilizing PaCO<inf>2</inf> during long-term non-invasive ventilation in subjects with COPD

Objective In subjects with chronic obstructive pulmonary disease (COPD), the effect of partial pressure of CO2 (PaCO2) alterations during long-term non-invasive ventilation (NIV) on continuance remains uncertain. We herein investigated the utility of PaCO2 stability during long-term NIV as a prognostic outcome. Methods We retrospectively assessed data from 54 subjects with COPD who received long-term NIV. Theannual alteration in PaCO2 during NIV was determined using a simple linear regression method for each subject who had at least two 6-month intervals of PaCO2 data. Annual alterations in PaCO2 during long-term NIV and probable confounders were examined, and long-term NIV discontinuation was the major outcome. Results Data from 37 subjects who met the criteria were analyzed. PaCO2 during long-term NIV increasedslightly in 19 subjects (group 1, 2 mmHg/y).In the multivariate modality model, smaller annual alterations in PaCO2 (p=0.009) and lower PaCO2 6 monthsafter the start of long-term NIV (6 m-PaCO2) (p=0.03) were associated with a significantly higher probability of continuing NIV. The 2- and 5-year probabilities of continuing NIV were 89% and 66% for group 1 and 78% and 32% for group 2, respectively. Conclusion A lower 6 m-PaCO2 and a lower annual alteration of PaCO2 during long-term NIV are significant predictive variables for patients with COPD

Low Levels of PaO₂ after Long-term Noninvasive Ventilation are a Poor Prognostic Factor in Patients with Restrictive Thoracic Disease

Objective: The effects of partial pressure of arterial oxygen (PaO₂) after introducing long-term noninvasive ventilation (NIV) on the prognosis of patients with restrictive thoracic disease and chronic respiratory failure are not exactly known. Methods: Data from 141 patients with restrictive thoracic disease under long-term nocturnal NIV were retrospectively examined. We divided the patients into 2 groups according to the daytime PaO₂ value while breathing spontaneously with prescribed oxygen at 12 months after introducing NIV: PaO₂≥80 Torr group (n=76) and PaO₂<80 Torr group (n=65). Results: During the 4-year follow-up, the mortality was significantly higher in the PaO₂<80 Torr group than in the PaO₂≥80 Torr group (50.8% vs. 32.9%, p=0.03). Independent factors associated with the 4-year mortality after introducing NIV determined by a multivariate logistic regression analysis were a low body mass index [odds ratio (OR) 0.87; 95% confidence interval (CI) 0.77 to 0.97; p=0.01], assisted mode with NIV (OR 4.11; 95% CI, 1.79 to 9.45; p=0.0009), hospitalization during the first year of introducing NIV (OR 1.72; 95% CI, 1.06 to 2.79; p=0.03), and daytime PaO₂<80 Torr at 12 months after introducing NIV (OR 2.30; 95% CI, 1.03 to 5.10; p=0.04). Conclusion: A low daytime PaO₂ at 12 months after introducing NIV was an independent risk factor for mortality. Keeping the daytime PaO₂≥80 Torr through the adjustment of the nocturnal NIV settings or increased diurnal supplemental oxygen may help improve the prognosis in patients with restrictive thoracic disease who are under NIV

Predictive Factors for Reintubation following Noninvasive Ventilation in Patients with Respiratory Complications after Living Donor Liver Transplantation.

[Background]Postoperative respiratory complications are a major cause of mortality following liver transplantation (LT). Noninvasive ventilation (NIV) appears to be effective for respiratory complications in patients undergoing solid organ transplantation; however, mortality has been high in patients who experienced reintubation in spite of NIV therapy. The predictors of reintubation following NIV therapy after LT are not exactly known.[Methods]Of 511 adult patients who received living-donor LT, data on the 179 who were treated by NIV were retrospectively examined. [Results]Forty-three (24%) of the 179 patients who received NIV treatment required reintubation. Independent factors associated with reintubation by multivariate logistic regression analysis were controlled preoperative infections (odds ratio [OR] 8.88; 95% confidence interval (CI) 1.64 to 48.11; p = 0.01), ABO-incompatibility (OR 4.49; 95% CI, 1.50 to 13.38; p = 0.007), and presence of postoperative pneumonia at the time of starting NIV (OR 3.28; 95% CI, 1.02 to 11.01; p = 0.04). The reintubated patients had a significant higher rate of postoperative infectious complications and a significantly longer intensive care unit stay than those in whom NIV was successful (p<0.0001). Of the 43 reintubated patients, 22 (51.2%) died during hospitalization following LT vs. 8 (5.9%) of the 136 patients in whom NIV was successful (p<0.0001). [Conclusions]Because controlled preoperative infection, ABO-incompatibility or pneumonia prior to the start of NIV were independent risk factors for reintubation following NIV, caution should be used in applying NIV in patients with these conditions considering the high rate of mortality in patients requiring reintubation following NIV

Importance of the PaCO(2) from 3 to 6 months after initiation of long-term non-invasive ventilation.

The level at which arterial carbon dioxide tension (PaCO(2)) a few months after introduction of long-term non-invasive positive pressure ventilation (NPPV) is associated with a favorable prognosis remains uncertain

Analysis of anatomical and functional determinants of obstructive sleep apnea.

[Purpose] Craniofacial abnormalities have an important role in the occurrence of obstructive sleep apnea (OSA) and may be particularly significant in Asian patients, although obesity and functional abnormalities such as reduced lung volume and increased airway resistance also may be important. We conducted simultaneous analyses of their interrelationships to evaluate the relative contributions of obesity, craniofacial structure, pulmonary function, and airway resistance to the severity of Japanese OSA because there are little data in this area. [Methods] A cross-sectional observational study was performed on 134 consecutive Japanese male patients. A sleep study, lateral cephalometry, pulmonary function tests, and impulse oscillometry (IOS) were performed on all patients. [Results] Age, body mass index (BMI), position of the hyoid bone, and proximal airway resistance on IOS (R20) were significantly related to the apnea/hypopnea index (AHI) (p < 0.05) in multiple regression analysis. Subgroup analysis showed that, for moderate-to-severe OSA (AHI ≥ 15 events/h), neck circumference and R20 were predominantly related to AHI, whereas for non-to-mild OSA (AHI < 15 events/h), age and expiratory reserve volume were the predominant determinants. In obese subjects (BMI ≥ 25 kg/m2), alveolar–arterial oxygen tension difference, position of the hyoid bone, and R20 were significantly associated with AHI, whereas age alone was a significant factor in nonobese subjects (BMI < 25 kg/m2). [Conclusions] Aside from age and obesity, anatomical and functional abnormalities are significantly related to the severity of Japanese OSA. Predominant determinants of AHI differed depending on the severity of OSA or the magnitude of obesity

Survival curve following LDLT in NIV success group and reintubation group.

<p>Patients who failed NIV had a significantly poorer prognosis (p = 0.0009). Abbreviations: LDLT, living-donor liver transplantation; NIV, noninvasive ventilation.</p