A Phase 2 interventional study of Inhaled Carbon Monoxide at 200 ppm and Inhaled Medical air in Acute Respiratory Distress Syndrome, sponsored by Brigham and Women's Hospital. Completed at 7 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-16.
Sponsored by Brigham and Women's Hospital · Phase 2, Interventional, and Treatment
This study will be a multi-center, prospective, randomized, partially double-blind, placebo-controlled Phase II clinical trial of inhaled CO (iCO) for the treatment of ARDS. The trial will be conducted at 7 tertiary care medical centers including Weill Cornell Medicine/NewYork-Presbyterian Hospital, Brigham and Women's Hospital (BWH), Massachusetts General Hospital (MGH), Duke University Hospital, Durham Veterans Administration Medical Center, New York-Presbyterian Brooklyn Methodist Hospital, and Duke Regional Hospital. The purpose of this study is to evaluate the safety, tolerability, and efficacy of inhaled carbon monoxide (iCO) for the treatment of ARDS and to examine the biologic readouts of low dose iCO therapy in patients with ARDS
Acute respiratory distress syndrome (ARDS) is a devastating disease affecting military, veteran, and civilian populations. ARDS is a syndrome of severe acute lung inflammation and hypoxemic respiratory failure with an incidence of 180,000 cases annually in the United States. Despite recent advances in critical care management and lung protective ventilation strategies, ARDS morbidity and mortality remain unacceptably high. The lack of specific effective therapies for ARDS indicates a need for new treatments that target novel pathways. Carbon monoxide (CO) represents a novel therapeutic modality in ARDS based on data obtained in experimental models of ARDS over the past decade.
CO has been shown to be protective in experimental models of acute lung injury (ALI) and sepsis. Furthermore, multiple human studies have demonstrated that experimental administration of several different concentrations of CO is well tolerated and that low dose inhaled CO can be safely administered to subjects in a controlled research environment. The investigators have previously conducted a Phase I trial of low dose iCO in ARDS which demonstrated that precise administration of low dose iCO (100 and 200 ppm) is feasible, well-tolerated, and safe in patients with sepsis-induced ARDS.
The purpose of this study is to assess the safety and efficacy of low dose inhaled carbon monoxide (iCO) therapy in mechanically ventilated patients with ARDS.
1,597 studies on the registry are indexed under Respiratory Distress Syndrome; 312 are open to participants now.
This study's enrollment of 4 is below the median of 60 across 961 interventional studies indexed under Respiratory Distress Syndrome.
Browse Respiratory Distress Syndrome studies →Brigham and Women's Hospital is the lead sponsor of 1,236 studies on the registry; 224 are open to participants now.
Of its 116 completed or terminated interventional studies of FDA-regulated products, 64 (55%) have results posted.
Counted across the registry records on this site, refreshed daily.
All intubated patients ≥ 18 years old with ARDS
ARDS is defined when all four of the following criteria are met:
Exclusion Criteria:
An individual who meets any of the following criteria will be excluded from participation in this study:
Inhaled Carbon Monoxide at 200 ppm for up to 90 minutes daily for 3 days.
Drug: Inhaled Carbon Monoxide at 200 ppm
Inhaled Medical Air for up to 90 minutes daily for 3 days.
Other: Inhaled Medical air
Inhaled Carbon Monoxide at 200 ppm for 90 minutes daily for 3 days.
Also known as: iCO
Inhaled Medical Air for up to 90 minutes daily for 3 days.
Primary Safety Outcome: Number of Pre-specified Administration-related Adverse Events.
Safety of inhaled CO, defined by the incidence of pre-specified administration-related AEs (as defined below) and spontaneously reported AEs through study day 7. 1. Acute MI within 48 hours of study drug administration 2. Acute cerebrovascular accident (CVA) within 48 hours of study drug administration 3. New onset atrial or ventricular arrhythmia requiring DC cardioversion within 48 hours of study drug administration 4. Increased oxygenation requirements defined as: an increase in FiO2 of ≥ 0.2 AND increase in PEEP ≥ 5 cm H2O within 6 hours of study drug administration 5. Increase in COHb ≥ 10% 6. Increase in lactate by ≥ 2 mmol/L within 6 hours of study drug administration
Time frame: 7 days
Primary Efficacy Outcome: Change in Mitochondrial DNA (mtDNA) Level From Day 1 to Day 5
Mitochondrial DNA (mtDNA) plasma levels will be measured by quantitative PCR of human NADH dehydrogenase 1. The number presented is the percentage average difference from beginning to end of treatment. Limited number of measurements prevents variance analyses; therefore we present the data from the subjects available in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Time frame: 5 days
Lung Injury Score (LIS) on Days 1-5, and on Days 1-7
The Lung Injury Score (LIS) is a composite 4-point scoring system including the PaO2/FiO2, PEEP, quasi-static respiratory compliance, and the extent of infiltrates on the chest X-ray. Each of the four components is categorized from 0 to 4, where a higher number is worse. The total Lung Injury Score is obtained by dividing the aggregate sum by the number of components used. Previous randomized clinical trials in ARDS have shown that a decreased LIS correlates with improvement in lung physiology as well as important clinical outcomes including mortality and ventilator-free days (VFDs). The number presented is the average difference from beginning to end of treatment. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Time frame: 7 days
Percent Change in PaO2/FiO2 Ratio on Days 1-5, and on Days 1-7
PaO2/FiO2 will be measured daily on days 1-5 and days 1-7 in ventilated subjects. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Time frame: 7 days
Percent Change in Oxygenation Index (OI) on Days 1-5, and Days 1-7
The oxygenation index will be measured on days 1-5 and on days 1-7 in ventilated subjects. Oxygenation index is calculated as (FiO2 X mean airway pressure)/PaO2. We provide change in Oi from baseline. Oi is only measured when subjects are ventilated, therefore not all timepoints are available. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Time frame: 7 days
Percent Change in Dead Space Fraction (Vd/Vt) on Days 1-3, and Days 1-7
The dead space fraction will be measured days 1-3 and days 1-7 in ventilated subjects. We present change in dead space fraction between initial and final measurements that were available (measurements only taken while the subjects were intubated). The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Time frame: 7 days
Percent Change in Sequential Organ Failure Assessment (SOFA) Score on Days 1-5, and Days 1-7.
Organ failure will be assessed using the SOFA score. SOFA scores will be assessed daily on days 1-5 and day 7, as the SOFA score has been shown to be a reliable prognostic indicator of outcomes in critically ill patients. To calculate the Sequential Organ Failure Assessment (SOFA) score, each of the six components (Respiratory, Coagulation, Liver, Cardiovascular, Central Nervous System, Renal) is categorized from 0-4, where a higher number is worse. The SOFA score (0-24) will be calculated by summing all six components. We present changes in SOFA score over the time of hospitalization, over the time of ICU admission (up to days 5 and 7 for the enrolled subjects). The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Time frame: 1-5 and 1-7 days
Absolute Value of Biomarkers of Inflammation and Inflammasome Activation
Cytokine plasma levels (eg. IL-1B) will be measured by ELISA daily on days 1-3 and on day 4. We report the absolute Mean Fluorescent Intensity (MFI) of each sample at pretreatment time point of day 4. Limited number of measurements prevents variance and measures of dispersion analyses; therefore we present the data from the subjects available in each group and report as "Number" without standard deviation, since measures of dispersion cannot be calculated.
Time frame: 4 days
Percent Change in Lipid Mediators
Lipid mediators (LM) and specialized pro-resolving mediators (SPMs) will be measured in plasma using liquid chromatography-tandem mass spectrometry (LC-MS-MS) based methods daily on days 1-3 and on day 4. The percentage change from baseline at day 1 to post treatment at day 4 is reported. A representative LM is shown (14-HDHA (14-hydroxy-4Z,7Z,10Z,12E,16Z,19Z-docosahexaenoic acid) is an oxidized metabolite of omega-3 docosahexaenoic acid (DHA)). Limited number of measurements prevents variance and measures of dispersion analyses; therefore we present the data from the subjects available in each group and report as "Number" without standard deviation, since measures of dispersion cannot be calculated.
Time frame: 4 days
Ventilator-free Days at Day 28
Ventilator-free days to day 28 are defined as the number of days from the time of initiating unassisted breathing to day 28 after randomization, assuming survival for at least two consecutive calendar days after initiating unassisted breathing and continued unassisted breathing to day 28. If a subject returns to assisted breathing and subsequently achieves unassisted breathing to day 28, VFDs will be counted from the end of the last period of assisted breathing to day 28. Participants who do not survive to day 28 are assigned zero ventilator-free days. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Time frame: 28 days
ICU-free Days at Day 28
ICU-free days are the number of days that the patient is alive and free from ICU care within 28 days. Is calculated by subtracting the total number of days that the patient is free from the ICU from 28. Patients who die within 28 days are automatically assigned "0" ICU free days. We present data of ICU free days for enrolled subjects. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Time frame: 28 days
Hospital-free Days at Day 60
Hospital-free days will be assessed on day 60. Hospital-free days are days alive post hospital discharge through day 60. Patients who die on or prior to day 60 are assigned zero hospital-free days. We present hospital free days at day 60. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Time frame: 60 days
Hospital Mortality to Day 28 and 60
Mortality will be assessed on day 28 and day 60
Time frame: 60 days
Montreal Cognitive Assessment- MoCA-Blind
Montreal Cognitive Assessment - Blind Version (MoCA-Blind) The MoCA-Blind is a remote adaptation of the Montreal Cognitive Assessment (MoCA) used as a screening assessment for detecting cognitive impairment. It is administered via telephone interview. The MoCA-Blind assesses the following cognitive domains (points): - Attention (0-6) - Language: (0-3 (Repetition (0-2) and fluency (0-1)) - Abstraction (0-2) - Memory: Delayed recall (0-5) - Orientation (0-6) The minimum score is 0 and maximum score is 22 points. Calculated as the sum of all domains. Interpretation: Higher scores indicate better cognitive functioning. Lower scores indicate worse cognitive functioning (greater cognitive impairment). A score of 18 or above is within the normal range. Limited number of measurements prevents variance and measures of dispersion analyses; therefore we present the data from the subjects available in each group and report as "Number", since given measures of dispersion cannot be calculated.
Time frame: 6 months
Hayling Sentence Completion Test
The Hayling Sentence Completion Test assesses executive functioning (response initiation and inhibition), administered via telephone. With 30 sentence-completion items split into 2 sections (15 each). Sections: - 1: Response initiation (time to provide a contextually appropriate word). - 2: Response inhibition (time and error score for providing an unrelated word). Scores (response time and errors) from both sections are combined and converted to an age-adjusted standardized total score. Total combined standardized score ranges from 1-10: 1: Impaired 2: Abnormal 3: Poor 4: Low Average 5: Moderate Average 6: Average 7: High Average 8: Good 9: Superior 10: Very Superior Higher scores= Better executive functioning Lower scores= Greater impairment. Limited number of measurements prevents variance and measures of dispersion analyses; therefore we present the data from the subjects available in each group and report as "Number", since given measures of dispersion cannot be calculated.
Time frame: 6 months
First recruited subject date was 9/30/2019 and last recruited subject was 4/5/2021. The study treatment was 3 days and follow up during 60 days during hospitalization and up to 6 months follow up. Screening was conducted in Intensive Care Units and qualifying subjects were consented by study physicians at Brigham and Women's Hospital, Duke University Hospital and New York Presbyterian Brooklyn Methodist Hospital.
| Milestone | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Started | 3 | 1 |
| Completed | 3 | 1 |
| Not completed | 0 | 0 |
Safety of inhaled CO, defined by the incidence of pre-specified administration-related AEs (as defined below) and spontaneously reported AEs through study day 7. 1. Acute MI within 48 hours of study drug administration 2. Acute cerebrovascular accident (CVA) within 48 hours of study drug administration 3. New onset atrial or ventricular arrhythmia requiring DC cardioversion within 48 hours of study drug administration 4. Increased oxygenation requirements defined as: an increase in FiO2 of ≥ 0.2 AND increase in PEEP ≥ 5 cm H2O within 6 hours of study drug administration 5. Increase in COHb ≥ 10% 6. Increase in lactate by ≥ 2 mmol/L within 6 hours of study drug administration
| Participants | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Acute MI within 48 hours of study drug administration | 0 | 0 |
| Acute cerebrovascular accident (CVA) within 48 hours of study drug administration | 1 | 0 |
| New arrhythmia requiring DC cardioversion within 48 hours of study drug administration | 0 | 0 |
| Increased oxygenation: increased FiO2 ≥ 0.2 AND PEEP ≥ 5 cm H2O within 6 hrs of drug administration | 0 | 0 |
| Increase in COHb ≥ 10% | 0 | 0 |
| Increase in lactate by ≥ 2 mmol/L within 6 hours of study drug administration | 0 | 0 |
Mitochondrial DNA (mtDNA) plasma levels will be measured by quantitative PCR of human NADH dehydrogenase 1. The number presented is the percentage average difference from beginning to end of treatment. Limited number of measurements prevents variance analyses; therefore we present the data from the subjects available in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
| Percent change in Mitochondrial DNA | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Primary Efficacy Outcome: Change in Mitochondrial DNA (mtDNA) Level From Day 1 to Day 5 | 234.14 ± 380.75 | -78.63 ± NA |
The Lung Injury Score (LIS) is a composite 4-point scoring system including the PaO2/FiO2, PEEP, quasi-static respiratory compliance, and the extent of infiltrates on the chest X-ray. Each of the four components is categorized from 0 to 4, where a higher number is worse. The total Lung Injury Score is obtained by dividing the aggregate sum by the number of components used. Previous randomized clinical trials in ARDS have shown that a decreased LIS correlates with improvement in lung physiology as well as important clinical outcomes including mortality and ventilator-free days (VFDs). The number presented is the average difference from beginning to end of treatment. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
| Percent change in Lung Injury Score | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Day 1 to Day 5 | -5.25 ± 15.31 | -30 ± NA |
| Day 1 to Day 7 | 3.11 ± 20.23 | -30 ± NA |
PaO2/FiO2 will be measured daily on days 1-5 and days 1-7 in ventilated subjects. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
| Percent change in PaO2/FiO2 ratio | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Day 1 to Day 5 | 32.74 ± 22.73 | 22.42 ± NA |
| Day 1 to Day 7 | 19.73 ± 14.86 | 40.60 ± NA |
The oxygenation index will be measured on days 1-5 and on days 1-7 in ventilated subjects. Oxygenation index is calculated as (FiO2 X mean airway pressure)/PaO2. We provide change in Oi from baseline. Oi is only measured when subjects are ventilated, therefore not all timepoints are available. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
| Percent change in O2 index from baseline | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Day 1 to Day 5 | -35.79 ± 24.04 | -40.09 ± NA |
| Day 1 to Day 7 | -24.31 ± 35.70 | -43.10 ± NA |
The dead space fraction will be measured days 1-3 and days 1-7 in ventilated subjects. We present change in dead space fraction between initial and final measurements that were available (measurements only taken while the subjects were intubated). The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
| Percent change in Dead Space | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Day 1 to Day 3 | -14.89 ± 21.06 | 3.03 ± NA |
| Day 1 to Day 7 | -27.65 ± Na | -10.60 ± NA |
Organ failure will be assessed using the SOFA score. SOFA scores will be assessed daily on days 1-5 and day 7, as the SOFA score has been shown to be a reliable prognostic indicator of outcomes in critically ill patients. To calculate the Sequential Organ Failure Assessment (SOFA) score, each of the six components (Respiratory, Coagulation, Liver, Cardiovascular, Central Nervous System, Renal) is categorized from 0-4, where a higher number is worse. The SOFA score (0-24) will be calculated by summing all six components. We present changes in SOFA score over the time of hospitalization, over the time of ICU admission (up to days 5 and 7 for the enrolled subjects). The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
| Percent change in SOFA score | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Day 1 to Day 5 | -8.88 ± 8.38 | 27.27 ± NA |
| Day 1 to Day 7 | -10.63 ± 24.02 | -9.09 ± NA |
Cytokine plasma levels (eg. IL-1B) will be measured by ELISA daily on days 1-3 and on day 4. We report the absolute Mean Fluorescent Intensity (MFI) of each sample at pretreatment time point of day 4. Limited number of measurements prevents variance and measures of dispersion analyses; therefore we present the data from the subjects available in each group and report as "Number" without standard deviation, since measures of dispersion cannot be calculated.
| Raw MFI units for IL-1B | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Absolute Value of Biomarkers of Inflammation and Inflammasome Activation | 151.23 ± NA | 307.83 ± NA |
Lipid mediators (LM) and specialized pro-resolving mediators (SPMs) will be measured in plasma using liquid chromatography-tandem mass spectrometry (LC-MS-MS) based methods daily on days 1-3 and on day 4. The percentage change from baseline at day 1 to post treatment at day 4 is reported. A representative LM is shown (14-HDHA (14-hydroxy-4Z,7Z,10Z,12E,16Z,19Z-docosahexaenoic acid) is an oxidized metabolite of omega-3 docosahexaenoic acid (DHA)). Limited number of measurements prevents variance and measures of dispersion analyses; therefore we present the data from the subjects available in each group and report as "Number" without standard deviation, since measures of dispersion cannot be calculated.
| Percent change 14-HDHA | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Percent Change in Lipid Mediators | 18.07 ± NA | -96.8 ± NA |
Ventilator-free days to day 28 are defined as the number of days from the time of initiating unassisted breathing to day 28 after randomization, assuming survival for at least two consecutive calendar days after initiating unassisted breathing and continued unassisted breathing to day 28. If a subject returns to assisted breathing and subsequently achieves unassisted breathing to day 28, VFDs will be counted from the end of the last period of assisted breathing to day 28. Participants who do not survive to day 28 are assigned zero ventilator-free days. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
| Days | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Ventilator-free Days at Day 28 | 0 ± 0 | 0 ± NA |
ICU-free days are the number of days that the patient is alive and free from ICU care within 28 days. Is calculated by subtracting the total number of days that the patient is free from the ICU from 28. Patients who die within 28 days are automatically assigned "0" ICU free days. We present data of ICU free days for enrolled subjects. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
| Days | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| ICU-free Days at Day 28 | 4.33 ± 4.50 | 2 ± NA |
Hospital-free days will be assessed on day 60. Hospital-free days are days alive post hospital discharge through day 60. Patients who die on or prior to day 60 are assigned zero hospital-free days. We present hospital free days at day 60. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
| Number of Hospital free Days at day 60 | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Hospital-free Days at Day 60 | 4.66 ± 8.08 | 0 ± NA |
Mortality will be assessed on day 28 and day 60
| Participants | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Day 28 | 2 | 0 |
| Day 60 | 2 | 0 |
Montreal Cognitive Assessment - Blind Version (MoCA-Blind) The MoCA-Blind is a remote adaptation of the Montreal Cognitive Assessment (MoCA) used as a screening assessment for detecting cognitive impairment. It is administered via telephone interview. The MoCA-Blind assesses the following cognitive domains (points): - Attention (0-6) - Language: (0-3 (Repetition (0-2) and fluency (0-1)) - Abstraction (0-2) - Memory: Delayed recall (0-5) - Orientation (0-6) The minimum score is 0 and maximum score is 22 points. Calculated as the sum of all domains. Interpretation: Higher scores indicate better cognitive functioning. Lower scores indicate worse cognitive functioning (greater cognitive impairment). A score of 18 or above is within the normal range. Limited number of measurements prevents variance and measures of dispersion analyses; therefore we present the data from the subjects available in each group and report as "Number", since given measures of dispersion cannot be calculated.
| scores on a scale | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Montreal Cognitive Assessment- MoCA-Blind | 10 | — |
The Hayling Sentence Completion Test assesses executive functioning (response initiation and inhibition), administered via telephone. With 30 sentence-completion items split into 2 sections (15 each). Sections: - 1: Response initiation (time to provide a contextually appropriate word). - 2: Response inhibition (time and error score for providing an unrelated word). Scores (response time and errors) from both sections are combined and converted to an age-adjusted standardized total score. Total combined standardized score ranges from 1-10: 1: Impaired 2: Abnormal 3: Poor 4: Low Average 5: Moderate Average 6: Average 7: High Average 8: Good 9: Superior 10: Very Superior Higher scores= Better executive functioning Lower scores= Greater impairment. Limited number of measurements prevents variance and measures of dispersion analyses; therefore we present the data from the subjects available in each group and report as "Number", since given measures of dispersion cannot be calculated.
| scores on a scale | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Hayling Sentence Completion Test | 4 | — |
Collected over Adverse events were monitored from enrollment to day 7. All-Cause Mortality was assessed up to 60 days.. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Inhaled Carbon Monoxide | 2/3 (66.7%) | 3/3 (100%) | 0/3 (0%) |
| Medical Air | 0/1 (0%) | 1/1 (100%) | 1/1 (100%) |
| Event | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Laryngeal edemaRespiratory, thoracic and mediastinal disorders | 0/3 | 1/1 |
| Intracranial hemorrhageNervous system disorders | 1/3 | 0/1 |
| Upper gastrointestinal hemorrhageGastrointestinal disorders | 1/3 | 0/1 |
| Respiratory failureRespiratory, thoracic and mediastinal disorders | 1/3 | 0/1 |
| Event | Inhaled Carbon Monoxide | Medical Air |
|---|---|---|
| Wound infectionInfections and infestations | 0/3 | 1/1 |
| SeizureNervous system disorders | 0/3 | 1/1 |
| Age, Categorical(Participants) | Inhaled Carbon Monoxide | Medical Air | Total |
|---|---|---|---|
| <=18 years | 0 | 0 | 0 |
| Between 18 and 65 years | 3 | 1 | 4 |
| >=65 years | 0 | 0 | 0 |
| Sex: Female, Male(Participants) | Inhaled Carbon Monoxide | Medical Air | Total |
|---|---|---|---|
| Female | 2 | 1 | 3 |
| Male | 1 | 0 | 1 |
| Race (NIH/OMB)(Participants) | Inhaled Carbon Monoxide | Medical Air | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 1 | 0 | 1 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 0 | 0 | 0 |
| White | 1 | 1 | 2 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 1 | 0 | 1 |
| Ethnicity (NIH/OMB)(Participants) | Inhaled Carbon Monoxide | Medical Air | Total |
|---|---|---|---|
| Hispanic or Latino | 1 | 0 | 1 |
| Not Hispanic or Latino | 2 | 1 | 3 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Baseline Critical Illness: Acute Respiratory Distress Syndrome (ARDS)(Participants) | Inhaled Carbon Monoxide | Medical Air | Total |
|---|---|---|---|
| Count of participants | 3 | 1 | 4 |
Documents are hosted by the registry — open the source record to download them.
Plan to share: No
This study is completed, as verified in May 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Respiratory Distress Syndrome→
Brigham and Women's Hospital