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Introduction/aims: Noninvasive ventilation (NIV) has been shown to improve survival and symptom burden in patients with amyotrophic lateral sclerosis (ALS). However, limited data exist regarding the clinical and physiological parameters at the time of NIV initiation. This study aimed to describe the clinical characteristics and respiratory physiological markers in a cohort of ALS patients with chronic respiratory failure., Methods: This is a single-center retrospective cohort study of patients with ALS assessed for NIV initiation between February 2012 and January 2021. NIV was initiated based on insurance eligibility criteria: daytime hypercapnia, defined by partial pressure of carbon dioxide (PaCO 2 ) >45 mm Hg using diurnal transcutaneous CO 2 (TcCO 2 ) as a surrogate, a maximal inspiratory pressure (MIP) <60 cmH 2 O or forced vital capacity (FVC) <50% predicted normal., Results: We identified 335 patients with ALS and chronic respiratory failure referred to an outpatient home ventilation clinic for NIV initiation. The mean age was 64 years ±11; 151 (45%) were female, 326 (97%) were white, and 100 (29%) had bulbar-onset ALS. At the time of NIV initiation, the mean FVC was 64% ± 19%, the mean MIP; 41 cmH 2 O ± 17, and diurnal TcCO 2 ; 40 ± 6 mmHg. The most common reasons for NIV initiation were MIP <60 cmH 2 O (58%) and multiple concomitant indications (28%). Within 1 year of NIV initiation, 126 (37%) patients were deceased., Discussion: We found that impairment in inspiratory force was the most common reason for NIV initiation and often preceded significant declines in FVC., (© 2024 The Author(s). Muscle & Nerve published by Wiley Periodicals LLC.)

Background: Chronic hypercapnic respiratory failure is associated with high mortality. Although previous work has demonstrated a mortality improvement with high-intensity noninvasive ventilation in COPD, it is unclear whether a P CO 2 reduction strategy is associated with improved outcomes in other populations of chronic hypercapnia., Methods: The objective of this study was to investigate the association between P CO 2 reduction (by using transcutaneous P CO 2 as an estimate for P aCO 2 and survival in a broad population of individuals treated with noninvasive ventilation for chronic hypercapnia. We hypothesized that reductions in P CO 2 would be associated with improved survival. Therefore, we performed a cohort study of all the subjects evaluated from February 2012 to January 2021 for noninvasive ventilation initiation and/or optimization due to chronic hypercapnia at a home ventilation clinic in an academic center. We used multivariable Cox proportional hazard models with time-varying coefficients and P CO 2 as a time-varying covariate to test the association between P CO 2 and all-cause mortality and when adjusting for known cofounders., Results: The mean ± SD age of 337 subjects was 57 ± 16 years, 37% women, and 85% white. In a univariate analysis, survival probability increased with reductions in P CO 2 to < 50 mm Hg after 90 d, and these remained significant after adjusting for age, sex, race, body mass index, diagnosis, Charlson comorbidity index, and baseline P CO 2 . In the multivariable analysis, the subjects who had a P aCO 2 < 50 mm Hg had a reduced mortality risk of 94% between 90 and 179 d (hazard ratio [HR] 0.06, 95% CI 0.01-0.50), 69% between 180 and 364 d (HR 0.31, 95% CI 0.12-0.79), and 73% for 365-730 d (HR 0.27, 95% CI 0.13-0.56)., Conclusions: Reduction in P CO 2 from baseline for subjects with chronic hypercapnia treated with noninvasive ventilation was associated with improved survival. Management strategies should target the greatest attainable reductions in P CO 2 ., Competing Interests: Dr Ackrivo discloses relationships with Hillrom and the National Institutes of Health National Heart, Lung and Blood Institute. Dr Labaki discloses relationships with Konica Minolta and Continuing Education Alliance. Dr Hansen-Flaschen discloses relationships with Revalesio Corporation. Dr Hyzy discloses relationships with Merck, Boehringer Ingelheim, Cour Pharmaceuticals, NOTA-Laboratories, Springer Website, UpToDate, CHEST Foundation and the NHLBI PETAL Network. Dr Choi discloses relationships with Breas Medical US. Dr Hsu discloses relationships with the National Kidney Foundation and PLOS ONE. The rest of the authors have no conflicts of interest., (Copyright © 2023 by Daedalus Enterprises.)

Introduction/aims: Amyotrophic lateral sclerosis (ALS) is characterized by profound muscle weakness, including diaphragmatic weakness resulting in hypercapnic respiratory failure. While non-invasive ventilation (NIV) is usually initiated in the home, patients presenting with hypercapnic respiratory failure may be at high risk of adverse outcomes with delays in treatment. We aim to describe the clinical utility of transcutaneous CO 2 (TCO 2 ) to assess the need for inpatient initiation of NIV., Methods: Eight patients from the University of Michigan Pranger ALS clinic were directly admitted to the hospital for urgent initiation of NIV between May 2020-May 2021. A retrospective review of electronic medical records, including pre-hospital pulmonary function assessments, hospitalization blood gases, and NIV use metrics was performed., Results: All eight patients had symptoms of respiratory insufficiency at time of admission, although not all patients had forced vital capacity (FVC) measurements that would identify need for NIV. All patients had measured TCO 2  > 45 mmHg. Seven of eight patients had worsening hypercapnia after admission, indicating advanced respiratory failure. All patients were titrated to tolerance of continuous nocturnal NIV while in the hospital, with an average length of stay of 6.5 days (range, 3-8). All patients demonstrated compliance with NIV, >4 h, at post-hospital follow-up., Discussion: Many current ambulatory measurements underestimate, or incompletely evaluate, respiratory dysfunction, and arterial blood gases are not typically readily available. Outpatient TCO 2 measurements can serve as a useful screening tool to identify ALS patients who would benefit from inpatient initiation and titration of NIV., (© 2022 Wiley Periodicals LLC.)

Rationale: Acute hypercapnic respiratory failure has been shown to be associated with worse outcomes for various disease states, but less is known about patients with compensated hypercapnic respiratory failure. Although these patients have a normal pH, it remains unknown whether chronically elevated carbon dioxide partial pressure (Pco 2 ), irrespective of etiology, puts patients at risk of adverse events. Objectives: To understand the burden of and clinical factors associated with morbidity and mortality in patients with compensated hypercapnic respiratory failure. Methods: We performed a query of the electronic medical record to identify patients hospitalized at the University of Michigan from January 1 to December 31, 2018, who had compensated hypercapnia, by using a Pco 2 ⩾ 50 mm Hg and a pH of 7.35-7.45 on arterial blood gas . We obtained demographic and clinical data from the electronic medical record. Survival probabilities for Pco 2 subgroups (50.0-54.9, 55.0-64.9, and ⩾65.0 mm Hg) were determined by using the Kaplan-Meier product limit estimator. Cox proportional hazard models were constructed to test the association between Pco 2 and all-cause mortality. Results: We identified 491 patients with compensated hypercapnia. The mean age was 60.5 ± 16.2 years. Patients were 57.4% male and 86.2% white. The mean pH and Pco 2 were 7.38 ± 0.03 and 58.8 ± 9.7 mm Hg, respectively. There was a total of 1,030 hospitalizations, with 44.4% of patients having two or more admissions. The median numbers of cumulative hospital and intensive care unit days were 21.0 (interquartile range [IQR], 11.0-38.0) and 7.0 (IQR, 3.0-14.0) days, respectively. Two hundred seventeen patients (44.2%) died over a median of 592 days. In univariate analysis, every 5-mm Hg increase in Pco 2 was associated with a higher risk of all-cause death (hazard ratio, 1.09; 95% confidence interval [CI]: 1.03-1.16; P  = 0.004). This association was maintained after adjusting for the age, sex, body mass index (BMI), and Charlson comorbidity index (hazard ratio of 1.09 for every 5-mm Hg increase in Pco 2 ; 95% CI: 1.02-1.16; P  = 0.009). There was a statistically significant interaction between the Pco 2 and the BMI in relation to mortality ( P  = 0.01 for the interaction term). Conclusions: Patients with compensated hypercapnic respiratory failure have high mortality and healthcare use, with higher Pco 2 being associated with worse survival. Hypercapnic patients with obesity have a higher risk of death with increases in Pco 2 .

Background: Amyotrophic Lateral Sclerosis (ALS) is a terminal neuromuscular disease with patients dying within 3-5 years of diagnosis. Most patients choose to forego invasive life sustaining measures. Timing of hospice referral can be challenging given the advancement of non-invasive ventilation (NIV) technology., Objective: To describe the characteristics of patients enrolled in hospice from an ALS clinic at 1 academic medical center and to perform a cost analysis for patients who remained on ventilator support., Methods: Retrospective cross-sectional study of patients enrolled in hospice over a 2-year period. Clinical characteristics included ALS Functional Rating Scale Revised (ALSFRS-R) score, Forced Vital Capacity (FVC), use of NIV and mechanical insufflation-exsufflation (MIE), riluzole use, and length of stay in hospice. A cost analysis was performed for patients enrolled in Duke Home Care and Hospice., Results: 85 of 104 patients who died were enrolled in hospice. Median days enrolled in hospice was 84. Patients who continued on NIV had similar hospice length of stay as those on no respiratory support (88 versus 80 days, p = 0.83). Bulbar patients had a trend toward shorter length of stay in hospice than limb onset patients (71 versus 101 days, p = 0.49). Cost analysis showed that hospice maintained a mean net operating revenue of $3234.50 per patient who continued on NIV., Conclusions: Hospice referrals for ALS patients on NIV can be challenging. This study shows that even with continued NIV use, most ALS patients die within the expected 6 months on home hospice, and care remains cost effective for hospice agencies.

Amyotrophic lateral sclerosis is a progressive neuromuscular disease characterized by both lower motor neuron and upper motor neuron dysfunction. Although clinical presentations can vary, there is no cure for ALS, and the disease is universally terminal, with most patients dying of respiratory complications. Patients die, on average, within 3 to 5 years of diagnosis, unless they choose to undergo tracheostomy, in which case, they may live, on average, 2 additional years. Up to 95% of patients with ALS in the United States choose not to undergo tracheostomy; management of respiratory failure is therefore aimed at both prolonging survival as well as improving quality of life. Standard of care for patients with ALS includes treatment from multidisciplinary teams, but many patients do not have consistent access to a pulmonary physician who regularly sees patients with this disease. The goal of this review was to serve as an overview of respiratory considerations in the management of ALS. This article discusses noninvasive ventilation in the management of respiratory muscle weakness, mechanical insufflation/exsufflation devices for airway clearance, and treatment of aspiration, including timing of placement of a percutaneous endoscopic gastrostomy tube, as well as secretion management. In addition, it is important for physicians to consider end-of-life issues such as advanced directives, hospice referral, and ventilator withdrawal., (Copyright © 2018 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)