Amal Jubran, Franco Laghi, Brydon J B Grant, Martin J Tobin
{"title":"Air Hunger Far Exceeds Dyspnea Sense of Effort during Mechanical Ventilation and a Weaning Trial.","authors":"Amal Jubran, Franco Laghi, Brydon J B Grant, Martin J Tobin","doi":"10.1164/rccm.202406-1243OC","DOIUrl":null,"url":null,"abstract":"<p><p><b>Rationale:</b> No systematic investigation into dyspnea in patients receiving prolonged ventilation (>21 d) after recovering from critical illness has been published. <b>Objectives:</b> We sought to determine the magnitude, nature, and pathophysiological basis of dyspnea during an unassisted-breathing trial in patients receiving prolonged ventilation. <b>Methods:</b> Dyspnea intensity and descriptor selection were investigated in 27 patients receiving prolonged ventilation during a 60-minute unassisted-breathing trial. Pressure-time product, respiratory mechanics, and Ptc<sub>CO<sub>2</sub></sub> were also measured. <b>Measurements and Main Results:</b> Of 10 patients who reported dyspnea during assist-control ventilation, 9 (90.0%) selected \"Not getting enough air\" to characterize dyspnea. Vt setting was lower in dyspneic than in nondyspneic patients (480.0 vs. 559.4 ml), <i>P</i> < 0.046. During the unassisted-breathing trial (<i>n</i> = 26), patients developed increases in dyspnea (<i>P</i> < 0.01) and Ptc<sub>CO<sub>2</sub></sub> (<i>P</i> < 0.01) but no change in [Formula: see text]e. Dyspnea score was strongly linked to Ptc<sub>CO<sub>2</sub></sub> (<i>P</i> < 0.012) and airway resistance (<i>P</i> < 0.013) but not respiratory work (although pressure-time product was almost three times higher than normal). At 60 minutes into the trial, 83.3% of patients selected \"Not getting enough air\" on its own or in combination with \"Too much effort\" to describe discomfort, whereas only 16.7% selected \"Too much effort\" on its own (<i>P</i> < 0.001). Across the dyspnea spectrum, patients chose \"Not getting enough air\" overwhelmingly over other descriptor options (<i>P</i> < 0.001). <b>Conclusions:</b> Patients developed increases in dyspnea and Ptc<sub>CO<sub>2</sub></sub> but unchanged [Formula: see text]e and work of breathing during an unassisted-breathing trial; patients selected air-hunger descriptors overwhelmingly over excessive effort. The observations support the belief that air hunger results from heightened respiratory center stimulation combined with the incapacity to increase [Formula: see text]e.</p>","PeriodicalId":7664,"journal":{"name":"American journal of respiratory and critical care medicine","volume":" ","pages":"323-330"},"PeriodicalIF":19.3000,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11936149/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"American journal of respiratory and critical care medicine","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1164/rccm.202406-1243OC","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CRITICAL CARE MEDICINE","Score":null,"Total":0}
引用次数: 0
Abstract
Rationale: No systematic investigation into dyspnea in patients receiving prolonged ventilation (>21 d) after recovering from critical illness has been published. Objectives: We sought to determine the magnitude, nature, and pathophysiological basis of dyspnea during an unassisted-breathing trial in patients receiving prolonged ventilation. Methods: Dyspnea intensity and descriptor selection were investigated in 27 patients receiving prolonged ventilation during a 60-minute unassisted-breathing trial. Pressure-time product, respiratory mechanics, and PtcCO2 were also measured. Measurements and Main Results: Of 10 patients who reported dyspnea during assist-control ventilation, 9 (90.0%) selected "Not getting enough air" to characterize dyspnea. Vt setting was lower in dyspneic than in nondyspneic patients (480.0 vs. 559.4 ml), P < 0.046. During the unassisted-breathing trial (n = 26), patients developed increases in dyspnea (P < 0.01) and PtcCO2 (P < 0.01) but no change in [Formula: see text]e. Dyspnea score was strongly linked to PtcCO2 (P < 0.012) and airway resistance (P < 0.013) but not respiratory work (although pressure-time product was almost three times higher than normal). At 60 minutes into the trial, 83.3% of patients selected "Not getting enough air" on its own or in combination with "Too much effort" to describe discomfort, whereas only 16.7% selected "Too much effort" on its own (P < 0.001). Across the dyspnea spectrum, patients chose "Not getting enough air" overwhelmingly over other descriptor options (P < 0.001). Conclusions: Patients developed increases in dyspnea and PtcCO2 but unchanged [Formula: see text]e and work of breathing during an unassisted-breathing trial; patients selected air-hunger descriptors overwhelmingly over excessive effort. The observations support the belief that air hunger results from heightened respiratory center stimulation combined with the incapacity to increase [Formula: see text]e.
期刊介绍:
The American Journal of Respiratory and Critical Care Medicine focuses on human biology and disease, as well as animal studies that contribute to the understanding of pathophysiology and treatment of diseases that affect the respiratory system and critically ill patients. Papers that are solely or predominantly based in cell and molecular biology are published in the companion journal, the American Journal of Respiratory Cell and Molecular Biology. The Journal also seeks to publish clinical trials and outstanding review articles on areas of interest in several forms. The State-of-the-Art review is a treatise usually covering a broad field that brings bench research to the bedside. Shorter reviews are published as Critical Care Perspectives or Pulmonary Perspectives. These are generally focused on a more limited area and advance a concerted opinion about care for a specific process. Concise Clinical Reviews provide an evidence-based synthesis of the literature pertaining to topics of fundamental importance to the practice of pulmonary, critical care, and sleep medicine. Images providing advances or unusual contributions to the field are published as Images in Pulmonary, Critical Care, Sleep Medicine and the Sciences.
A recent trend and future direction of the Journal has been to include debates of a topical nature on issues of importance in pulmonary and critical care medicine and to the membership of the American Thoracic Society. Other recent changes have included encompassing works from the field of critical care medicine and the extension of the editorial governing of journal policy to colleagues outside of the United States of America. The focus and direction of the Journal is to establish an international forum for state-of-the-art respiratory and critical care medicine.