The end-tidal alveolar dead space fraction for risk stratification during the first week of invasive mechanical ventilation: an observational cohort study
Abstract Background The end-tidal alveolar dead space fraction (AVDSf = [PaCO2−PETCO2]/PaCO2) is a metric used to estimate alveolar dead space. Higher AVDSf on the first day of mechanical ventilation is associated with mortality and fewer ventilator-free days. It is not clear if AVDSf is associated...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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BMC
2023-02-01
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| Series: | Critical Care |
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| Online Access: | https://doi.org/10.1186/s13054-023-04339-3 |
| _version_ | 1811165930500128768 |
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| author | Anoopindar K. Bhalla Ariya Chau Robinder G. Khemani Christopher J. L. Newth |
| author_facet | Anoopindar K. Bhalla Ariya Chau Robinder G. Khemani Christopher J. L. Newth |
| author_sort | Anoopindar K. Bhalla |
| collection | DOAJ |
| description | Abstract Background The end-tidal alveolar dead space fraction (AVDSf = [PaCO2−PETCO2]/PaCO2) is a metric used to estimate alveolar dead space. Higher AVDSf on the first day of mechanical ventilation is associated with mortality and fewer ventilator-free days. It is not clear if AVDSf is associated with length of ventilation in survivors, how AVDSf performs for risk stratification beyond the first day of ventilation, or whether AVDSf adds predictive value to oxygenation (oxygenation index [OI]) or severity of illness (Pediatric Risk of Mortality [PRISM III]) markers. Methods Retrospective single-center observational cohort study of children and young adults receiving invasive mechanical ventilation. In those with arterial or capillary blood gases, AVDSf was calculated at the time of every blood gas for the first week of mechanical ventilation. Results There were 2335 children and young adults (median age 5.8 years [IQR 1.2, 13.2]) enrolled with 8004 analyzed AVDSf values. Higher AVDSf was associated with mortality and longer length of ventilation in survivors throughout the first week of ventilation after controlling for OI and PRISM III. Higher OI was not associated with increased mortality until ≥ 48 h of ventilation after controlling for AVDSf and PRISM III. When using standardized variables, AVDSf effect estimates were generally higher than OI for mortality, whereas OI effect estimates were generally higher than AVDSf for the length of ventilation in survivors. An AVDSf > 0.3 was associated with a higher mortality than an AVDSf < 0.2 within each pediatric acute respiratory distress syndrome severity category. The maximum AVDSf within 12 h of intensive care unit admission demonstrated good risk stratification for mortality (AUC 0.768 [95% CI 0.732, 0.803]). AVDSf did not improve mortality risk stratification when added to PRISM III but did improve mortality risk stratification when added to the gas exchange components of PRISM III (minimum 12-h PaO2 and maximum 12-h PCO2) (p < 0.00001). Conclusions AVDSf is associated with mortality and length of ventilation in survivors throughout the first week of invasive mechanical ventilation. Some analyses suggest AVDSf may better stratify mortality risk than OI, whereas OI may better stratify risk for prolonged ventilation in survivors than AVDSf. |
| first_indexed | 2024-04-10T15:44:13Z |
| format | Article |
| id | doaj.art-731734747df74ed9a2c42f3541e527eb |
| institution | Directory Open Access Journal |
| issn | 1364-8535 |
| language | English |
| last_indexed | 2024-04-10T15:44:13Z |
| publishDate | 2023-02-01 |
| publisher | BMC |
| record_format | Article |
| series | Critical Care |
| spelling | doaj.art-731734747df74ed9a2c42f3541e527eb2023-02-12T12:13:33ZengBMCCritical Care1364-85352023-02-012711910.1186/s13054-023-04339-3The end-tidal alveolar dead space fraction for risk stratification during the first week of invasive mechanical ventilation: an observational cohort studyAnoopindar K. Bhalla0Ariya Chau1Robinder G. Khemani2Christopher J. L. Newth3Department of Anesthesiology and Critical Care Medicine, Children’s Hospital Los Angeles, Department of Pediatrics, Keck School of Medicine, University of Southern CaliforniaDivision of Cardiology, Department of Pediatrics, Lucile Packard Children’s Hospital at Stanford, Stanford University School of MedicineDepartment of Anesthesiology and Critical Care Medicine, Children’s Hospital Los Angeles, Department of Pediatrics, Keck School of Medicine, University of Southern CaliforniaDepartment of Anesthesiology and Critical Care Medicine, Children’s Hospital Los Angeles, Department of Pediatrics, Keck School of Medicine, University of Southern CaliforniaAbstract Background The end-tidal alveolar dead space fraction (AVDSf = [PaCO2−PETCO2]/PaCO2) is a metric used to estimate alveolar dead space. Higher AVDSf on the first day of mechanical ventilation is associated with mortality and fewer ventilator-free days. It is not clear if AVDSf is associated with length of ventilation in survivors, how AVDSf performs for risk stratification beyond the first day of ventilation, or whether AVDSf adds predictive value to oxygenation (oxygenation index [OI]) or severity of illness (Pediatric Risk of Mortality [PRISM III]) markers. Methods Retrospective single-center observational cohort study of children and young adults receiving invasive mechanical ventilation. In those with arterial or capillary blood gases, AVDSf was calculated at the time of every blood gas for the first week of mechanical ventilation. Results There were 2335 children and young adults (median age 5.8 years [IQR 1.2, 13.2]) enrolled with 8004 analyzed AVDSf values. Higher AVDSf was associated with mortality and longer length of ventilation in survivors throughout the first week of ventilation after controlling for OI and PRISM III. Higher OI was not associated with increased mortality until ≥ 48 h of ventilation after controlling for AVDSf and PRISM III. When using standardized variables, AVDSf effect estimates were generally higher than OI for mortality, whereas OI effect estimates were generally higher than AVDSf for the length of ventilation in survivors. An AVDSf > 0.3 was associated with a higher mortality than an AVDSf < 0.2 within each pediatric acute respiratory distress syndrome severity category. The maximum AVDSf within 12 h of intensive care unit admission demonstrated good risk stratification for mortality (AUC 0.768 [95% CI 0.732, 0.803]). AVDSf did not improve mortality risk stratification when added to PRISM III but did improve mortality risk stratification when added to the gas exchange components of PRISM III (minimum 12-h PaO2 and maximum 12-h PCO2) (p < 0.00001). Conclusions AVDSf is associated with mortality and length of ventilation in survivors throughout the first week of invasive mechanical ventilation. Some analyses suggest AVDSf may better stratify mortality risk than OI, whereas OI may better stratify risk for prolonged ventilation in survivors than AVDSf.https://doi.org/10.1186/s13054-023-04339-3VentilatorsMechanicalRespiratory distress syndromeMortalityPediatricsCritical care outcomes |
| spellingShingle | Anoopindar K. Bhalla Ariya Chau Robinder G. Khemani Christopher J. L. Newth The end-tidal alveolar dead space fraction for risk stratification during the first week of invasive mechanical ventilation: an observational cohort study Critical Care Ventilators Mechanical Respiratory distress syndrome Mortality Pediatrics Critical care outcomes |
| title | The end-tidal alveolar dead space fraction for risk stratification during the first week of invasive mechanical ventilation: an observational cohort study |
| title_full | The end-tidal alveolar dead space fraction for risk stratification during the first week of invasive mechanical ventilation: an observational cohort study |
| title_fullStr | The end-tidal alveolar dead space fraction for risk stratification during the first week of invasive mechanical ventilation: an observational cohort study |
| title_full_unstemmed | The end-tidal alveolar dead space fraction for risk stratification during the first week of invasive mechanical ventilation: an observational cohort study |
| title_short | The end-tidal alveolar dead space fraction for risk stratification during the first week of invasive mechanical ventilation: an observational cohort study |
| title_sort | end tidal alveolar dead space fraction for risk stratification during the first week of invasive mechanical ventilation an observational cohort study |
| topic | Ventilators Mechanical Respiratory distress syndrome Mortality Pediatrics Critical care outcomes |
| url | https://doi.org/10.1186/s13054-023-04339-3 |
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