title: Severe hypercapnia and outcome of mechanically ventilated patients with moderate or severe acute respiratory distress syndrome.
abstract: OBJECTIVE
  To analyze the relationship between hypercapnia developing within the first 48 h after the start of mechanical ventilation and outcome in patients with acute respiratory distress syndrome (ARDS).
  
  
  METHODS
  We performed a secondary analysis of three prospective non-interventional cohort studies focusing on ARDS patients from 927 intensive care units (ICUs) in 40 countries. These patients received mechanical ventilation for more than 12 h during 1-month periods in 1998, 2004, and 2010. We used multivariable logistic regression and a propensity score analysis to examine the association between hypercapnia and ICU mortality.
  
  
  RESULTS
  We included 1899 patients with ARDS in this study. The relationship between maximum PaCO2in the first 48 h and mortality suggests higher mortality at or above PaCO2of ≥50 mmHg. Patients with severe hypercapnia (PaCO2≥50 mmHg) had higher complication rates, more organ failures, and worse outcomes. After adjusting for age, SAPS II score, respiratory rate, positive end-expiratory pressure, PaO2/FiO2ratio, driving pressure, pressure/volume limitation strategy (PLS), corrected minute ventilation, and presence of acidosis, severe hypercapnia was associated with increased risk of ICU mortality [odds ratio (OR) 1.93, 95% confidence interval (CI) 1.32 to 2.81; p = 0.001]. In patients with severe hypercapnia matched for all other variables, ventilation with PLS was associated with higher ICU mortality (OR 1.58, CI 95% 1.04-2.41; p = 0.032).
  
  
  CONCLUSIONS
  Severe hypercapnia appears to be independently associated with higher ICU mortality in patients with ARDS.
  
  
  BACKGROUND
  Clinicaltrials.gov identifier, NCT01093482.
authors.affiliation: Hospital de Torrejón, Madrid, Spain.|Hospital Español, Montevideo, Uruguay.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Nin
authors.affiliation: Department of Clinical Biostatistics, Hospital Ramón Y Cajal, IRICYS and CIBERESP, Madrid, Spain.
authors.forename: Alfonso
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authors.lastname: Muriel
authors.affiliation: CIBER Enfermedades Respiratorias, Madrid, Spain.|Hospital Universitario de Getafe, Carretera de Toledo, Km 12,500, 28905, Madrid, Spain.
authors.forename: Oscar
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authors.lastname: Peñuelas
authors.affiliation: Keenan Research Centre, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Canada.|Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada.
authors.forename: Laurent
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authors.lastname: Brochard
authors.affiliation: CIBER Enfermedades Respiratorias, Madrid, Spain.|Hospital Universitario de Getafe, Carretera de Toledo, Km 12,500, 28905, Madrid, Spain.
authors.forename: José Angel
authors.initials: JA
authors.lastname: Lorente
authors.affiliation: Interdepartmental Division of Critical Care Medicine and Departments of Medicine and Physiology, University of Toronto, Toronto, Canada.
authors.forename: Niall D
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authors.lastname: Ferguson
authors.affiliation: Medizinische Hochschule Hannover, Hanover, Germany.
authors.forename: Konstantinos
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authors.affiliation: Hospital Nacional Alejandro Posadas, Buenos Aires, Argentina.
authors.forename: Fernando
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authors.affiliation: Hospital HIGA Guemes, Haedo, Argentina.
authors.forename: Damian A
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authors.affiliation: University Hospital of Poitiers, Poitiers, France.
authors.forename: Arnaud W
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authors.affiliation: Clínica Medellín and Universidad Pontificia Bolivariana, Medellín, Colombia.
authors.forename: Marco
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authors.affiliation: Hospital Regional 1° de Octubre, ISSSTE, Mexico City, Mexico.
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authors.affiliation: Hospital Español, Montevideo, Uruguay.
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authors.affiliation: Alfred Hospital and Monash University, Melbourne, Australia.
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authors.affiliation: Peking Union Medical College Hospital, Beijing, People's Republic of China.
authors.forename: Bin
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authors.affiliation: Policlinico Agostino Gemelli, Università Cattolica Del Sacro Cuore, Rome, Italy.
authors.forename: Salvatore M
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authors.affiliation: Instituto Nacional del Tórax de Santiago, Santiago, Chile.
authors.forename: Luis
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authors.affiliation: Hospital de Clínicas de Caracas, Caracas, Venezuela.
authors.forename: Gabriel
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authors.affiliation: Papageorgiou Hospital, Thessaloniki, Greece.
authors.forename: Dimitrios
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authors.lastname: Matamis
authors.affiliation: Hospital Fattouma Bourguina, Monastir, Tunisia.
authors.forename: Fekri
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authors.lastname: Abroug
authors.affiliation: UCINC, Hospital de Sao José, Centro Hospitalar de Lisboa Central, E.P.E., Lisbon, Portugal.
authors.forename: Rui P
authors.initials: RP
authors.lastname: Moreno
authors.affiliation: Hospital Universitario Sao José, Belo Horizonte, Brazil.
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Soares
authors.affiliation: King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
authors.forename: Yaseen
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authors.lastname: Arabi
authors.affiliation: Hospital Obrero No. 1, La Paz, Bolivia.
authors.forename: Freddy
authors.initials: F
authors.lastname: Sandi
authors.affiliation: Hospital Eugenio Espejo, Quito, Ecuador.
authors.forename: Manuel
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authors.lastname: Jibaja
authors.affiliation: Bombay Hospital Institute of Medical Sciences, Mumbai, India.
authors.forename: Pravin
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authors.lastname: Amin
authors.affiliation: Asan Medical Center, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Younsuck
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authors.lastname: Koh
authors.affiliation: Medical Center Leeuwarden (MCL), Leeuwarden, The Netherlands.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kuiper
authors.affiliation: Holbaek Hospital, University of Copenhagen, Copenhagen, Region Zealand, Denmark.
authors.forename: Hans-Henrik
authors.initials: HH
authors.lastname: Bülow
authors.affiliation: Hospital Ibn Sina, Rabat, Morocco.
authors.forename: Amine Ali
authors.initials: AA
authors.lastname: Zeggwagh
authors.affiliation: South Texas Veterans Health Care System and University of Texas Health Science Center, San Antonio, TX, USA.
authors.forename: Antonio
authors.initials: A
authors.lastname: Anzueto
authors.affiliation: Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Jacob I
authors.initials: JI
authors.lastname: Sznajder
authors.affiliation: CIBER Enfermedades Respiratorias, Madrid, Spain. aesteban@ucigetafe.com.|Hospital Universitario de Getafe, Carretera de Toledo, Km 12,500, 28905, Madrid, Spain. aesteban@ucigetafe.com.
authors.forename: Andres
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mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000209:etiology / Q000401:mortality* / Q000628:therapy; D007362:Intensive Care Units; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D057216:Propensity Score; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000009:adverse effects*; D012128:Respiratory Distress Syndrome / Q000150:complications / Q000401:mortality* / Q000628:therapy; D012720:Severity of Illness Index; D000072878:Simplified Acute Physiology Score; D013997:Time Factors
keywords: Acute respiratory distress syndrome; Hypercapnia; ICU mortality; Mechanical ventilation