Noninvasive Ventilation in Obese Subjects After Acute Respiratory Failure.

Noninvasive ventilation (NIV) has been widely used to treat acute respiratory failure in obese patients. Criteria that could help clinicians to decide whether they should continue to use NIV after such an initial episode remain unclear. Our retrospective study aims to analyze characteristics of subjects receiving long-term NIV after an initial hospitalization for acute respiratory failure. From January 2011 to December 2012, 77 obese adults were admitted in the ICU of the respiratory disease department in Nantes University Hospital in France. After discharge, adherence, body mass index (BMI), and arterial blood gases were assessed or measured at 6 months and 12 months. In all, 53 subjects were analyzed, including 62% who were admitted for idiopathic acute hypercapnic respiratory failure. Mean BMI was 42 ± 11 kg/m2. Failure of NIV occurred in 10% cases in the ICU. At the end of the hospital stay, 34 subjects were discharged with NIV at home. They had higher BMI and higher initial inspiratory positive airway pressure than those who were not ventilated at home. During follow-up, BMI, PaCO2 , and bicarbonate rate significantly decreased. At 12 months, 4 subjects were not ventilated anymore after a mean duration of 6 ± 4.2 months of ventilation. Adherence was correct in 86%, with a mean use of 7 ± 3.1 h/d. Adherent subjects had better adherence at 1 month, a lower forced vital capacity, a higher bicarbonate rate, and a higher NIV breathing frequency when compared to subjects with poor adherence. Subjects with the most severe obesity or who experienced the most difficult initial ventilation were more likely to receive long-term NIV after initial management of acute respiratory failure in the ICU. In those subjects, long-term NIV at home was effective and well tolerated.

Bry C ，Jaffré S ，Guyomarc'h B ，Corne F ，Chollet S ，Magnan A ，Blanc FX ... -  《-》

Acute Respiratory Failure in Obesity-Hypoventilation Syndrome Managed in the ICU.

Obesity-hypoventilation syndrome (OHS) is defined as the combination of obesity (body mass index ≥ 30 kg/m2) and daytime arterial hypercapnia (PaCO2 > 45 mm Hg) in the absence of other causes of hypoventilation, and can lead to acute hypercapnic respiratory failure in the ICU. Our objective was to describe the ventilatory management and outcomes of subjects with OHS who were admitted to the ICU for acute hypercapnic respiratory failure. We retrospectively built a cohort of subjects with OHS who were admitted for acute hypercapnic respiratory failure in 4 ICUs of the university teaching hospital in Lyon, France, between 2013 and 2017. The main end point was the rate of success of noninvasive ventilation (NIV). Secondary end points were survival from OHS diagnosis to the last follow-up and risk factors for ICU admission and long-term survival. One hundred fifteen subjects with OHS were included. Thirty-seven subjects (32.1%) were admitted to the ICU for acute hypercapnic respiratory failure. Congestive heart failure was the leading cause of acute hypercapnic respiratory failure (54%). At ICU admission, pH before NIV use was median (range) 7.26 (7.22-7.31) and PaCO2 was 70 (61-76) mm Hg. NIV was used as first-line ventilatory support in 36 subjects (97.2%) and was successful in 33 subjects (91.7%). ICU mortality was low (2.7%). The subjects admitted to the ICU were significantly older and had a lower FEV1 and vital capacity at the time of an OHS diagnosis. The difference in the restricted mean survival time was 663 d in favor of subjects not admitted to the ICU. Multivariate analysis showed that lower vital capacity at an OHS diagnosis was significantly associated with a higher risk of ICU admission. No factor was independently associated with long-term overall mortality in multivariate analysis. Acute hypercapnic respiratory failure in subjects with OHS was generally responsive to NIV and was frequently associated with congestive heart failure.

Chebib N ，Nesme P ，Freymond N ，Argaud L ，Rimmelé T ，Bohé J ，Devouassoux G ，Souquet PJ ，Guérin C ... -  《-》

Performance of noninvasive ventilation in acute respiratory failure in critically ill patients: a prospective, observational, cohort study.

Corrêa TD ，Sanches PR ，de Morais LC ，Scarin FC ，Silva E ，Barbas CS ... -  《BMC Pulmonary Medicine》

Volume-Targeted Versus Pressure-Limited Noninvasive Ventilation in Subjects With Acute Hypercapnic Respiratory Failure: A Multicenter Randomized Controlled Trial.

Volume-targeted noninvasive ventilation (VT-NIV), a hybrid mode that delivers a preset target tidal volume (VT) through the automated adjustment of pressure support, could guarantee a relatively constant target VT over pressure-limited noninvasive ventilation (PL-NIV) with fixed-level pressure support. Whether VT-NIV is more effective in improving ventilatory status in subjects with acute hypercapnic respiratory failure (AHRF) remains unclear. Our aim was to verify whether, in comparison with PL-NIV, VT-NIV would be more effective in correcting hypercapnia, hence reducing the need for intubation and improving survival in subjects with AHRF. We performed a prospective randomized controlled trial in the general respiratory wards of 8 university-affiliated hospitals in China over a 12-month period. Subjects with AHRF, defined as arterial pH <7.35 and ≥7.25 and PaCO2 >45 mm Hg, were randomly assigned to undergo PL-NIV or VT-NIV. The primary end point was the decrement of PaCO2 from baseline to 6 h after randomization. Secondary end points included the decrement of PaCO2 from baseline to 2 h after randomization as well as outcomes of subjects (eg, need for intubation, in-hospital mortality). A total of 58 subjects were assigned to PL-NIV (29 subjects) or VT-NIV (29 subjects) and included in the analyses. The decrement of PaCO2 from baseline to 6 h after randomization was not statistically different between the PL-NIV group and the VT-NIV group (9.3 ± 12.6 mm Hg vs 11.7 ± 12.9 mm Hg, P = .48). There were no differences between the PL-NIV group and the VT-NIV group in the decrement of PaCO2 from baseline to 2 h after randomization (6.4 ± 12.7 mm Hg vs 5.0 ± 15.8 mm Hg, P = .71) as well as in the need for intubation (17.2% vs 10.3%, P = .70), and in-hospital mortality (10.3% vs 6.9%, P > .99). Regardless of whether a VT- or PL-NIV strategy is employed, it is possible to provide similar support to subjects with AHRF. (ClinicalTrials.gov registration NCT02538263.).

Cao Z ，Luo Z ，Hou A ，Nie Q ，Xie B ，An X ，Wan Z ，Ye X ，Xu Y ，Chen X ，Zhang H ，Xu Z ，Wang J ，An F ，Li P ，Yu C ，Liang Y ，Zhang Y ，Ma Y ... -  《-》

Noninvasive ventilation for acute hypercapnic respiratory failure: intubation rate in an experienced unit.

Contou D ，Fragnoli C ，Córdoba-Izquierdo A ，Boissier F ，Brun-Buisson C ，Thille AW ... -  《-》