{"doi":"10.1002/mus.28366","title":"Identifying Daytime Hypercapnia Using Transcutaneous Carbon Dioxide Monitoring in Patients With Amyotrophic Lateral Sclerosis","abstract":"ABSTRACT Introduction/Aims Respiratory failure from hypoventilation is the most common cause of death in amyotrophic lateral sclerosis (ALS). However, ALS care rarely assesses hypercapnia, a physiologic measure of hypoventilation. We investigated the prevalence and clinical significance of daytime hypercapnia measured by transcutaneous carbon dioxide (tcCO 2 ) monitoring in patients with ALS. Methods This retrospective study included patients seen at two ALS clinics in the United States between 2012 and 2024 who had tcCO 2 measured concurrently with pulmonary function tests (PFTs), which included forced vital capacity (FVC) and, at one site, maximum inspiratory pressure (MIP). We assessed the prevalence of hypercapnia (tcCO 2 > 45 mmHg), the sensitivity and specificity of patient symptoms and PFTs for hypercapnia, and the relationship between hypercapnia and survival. Results Daytime hypercapnia was present in 33/328 (10%) patients at baseline. Hypercapnia was associated with an increased rate of death (aHR 2.1, 95% CI 1.4–3.3). Orthopnea or dyspnea was 70% sensitive for hypercapnia (95% CI 51%–84%). Absolute value of MIP (|MIP|) < 60 cmH 2 O was 95% sensitive (95% CI 74%–100%) and 22% specific (95% CI 16%–30%), FVC < 50% predicted was 33% sensitive (95% CI 18%–52%) and 82% specific (95% CI 78%–87%), and FVC < 80% predicted was 85% sensitive (95% CI 68%–95%) and 31% specific (95% CI 26%–36%) for hypercapnia. Discussion TcCO 2 monitoring identified strengths and weaknesses of PFTs in identifying hypercapnia in ALS. We found high sensitivity of |MIP| < 60 cmH 2 O and FVC < 80% predicted and high specificity of FVC < 50% predicted. Prospective studies should investigate the optimal clinical role for tcCO 2 .","journal":"Muscle & Nerve","year":2025,"id":550167,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9581,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1070756,"name":"José Víctor Jiménez","orcid":"0000-0002-9209-0327","position":1,"is_corresponding":false},{"id":337715,"name":"Jesse Y. Hsu","orcid":"0000-0002-1522-6534","position":2,"is_corresponding":false},{"id":495593,"name":"Lauren Elman","orcid":"0000-0003-4706-950X","position":3,"is_corresponding":false},{"id":1070759,"name":"Philip J. Choi","orcid":"0000-0003-3609-5999","position":4,"is_corresponding":false},{"id":1061384,"name":"Jason Ackrivo","orcid":"0000-0003-4379-1255","position":5,"is_corresponding":false},{"id":262105,"name":"Alexander H. Morrison","orcid":"0000-0002-6141-5352","position":0,"is_corresponding":true}],"reference_count":41,"raw_metadata":null,"created_at":"2026-07-19T02:54:16.596730Z","pmid":"39936179","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}