Changes in Exhaled 13CO2/12CO2 Breath Delta Value as an Early Indicator of Infection in ICU Patients

Carbon-12 and carbon-13 are naturally-abundant isotopes in exhaled breath carbon dioxide. The ratio of carbon-13 to carbon-12 in exhaled breath is known as the breath delta value (BDV). This study is seeking to determine if the breath delta value of critically ill adults is an early indicator of the onset of infection that may lead to sepsis.

Study Overview

• Status: Completed
• Conditions: Sepsis
• Intervention / Treatment: Device: Isomark Canary™

Detailed Description

Sepsis is a major complication for any patient, and its management is an acknowledged challenge for intensivists. Sepsis has unpredictable onset and progression, and is a leading cause of death in ICUs with a mortality rate of 30-50%. Annually in the US, 1.4M cases involve hospitalization, 750,000 cases of severe sepsis or septic shock, and ~260,000 cases of sepsis related death have been reported in recent years. Current experience of UF Health investigators in surgical ICUs is 1 -2 sepsis, severe sepsis, or septic shock patients per day, of which ~10% are trauma patients. Of trauma patients, ~8% develop sepsis during their ICU stay.

Breath delta value is hypothesized to be a biomarker of infection. Breath delta value is not a defined clinical outcome related to human health, because this study is seeking to establish breath delta value as a biomarker of infection. This study is measuring the feasibility of the Isomark Canary™ device. If the Canary does not detect a significant decrease in breath delta value in those subjects who subsequently get an infection, it will not be feasible to use it for this purpose.

Breath delta value will be collected to determine its relationship to infection, no health outcomes are being measured.

This study is designed to determine if the BDV of adult ICU patients is an early indicator of the onset of infection that may lead to sepsis.

The objectives of this study are: (1) to measure variation of BDV with time in adult ICU patients who agree to participate as research subjects; (2) to determine the magnitude of change of BDV in subjects who are subsequently diagnosed with severe infection and sepsis; (3) to define variation of BDV in adult trauma subjects who do not develop severe infection.

• Study Type: Interventional
• Enrollment (Actual): 32
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Florida
    • Gainesville, Florida, United States, 32608
      • University of Florida Health
    • Jacksonville, Florida, United States, 32209
      • University of Florida
  • Missouri
    • Saint Louis, Missouri, United States, 63110
      • Washington University School of Medicine
  • Ohio
    • Columbus, Ohio, United States, 43210
      • The Ohio State University
  • Wisconsin
    • Madison, Wisconsin, United States, 53706
      • University of Wisconsin - Madison
    • Madison, Wisconsin, United States, 53711
      • Isomark, LLC

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. age 18 years or older
2. critically ill patient admitted to trauma or surgical ICU
3. expected duration of hospital stay at least 120 hours (five days) from time of study enrollment
4. subject/LAR speaks a language of which the IRB has approved a consent form

Exclusion Criteria:

1. known infection at the time of enrollment per infection definitions in section 6.2
2. known use of systemic antibiotic, antimicrobial and/or antifungal therapy within the last 7 days (See Antibiotic Use section below)
3. prolonged antibiotic or antimicrobial use during the perioperative period (See Antibiotic Use section below)
4. currently active cancer, or receiving treatment for cancer (including but not limited to: radiation, chemotherapy, systemic orals, etc)
5. receiving high frequency ventilatory support
6. if not intubated, unable to cooperate with providing a breath sample
7. expected death within 24 hours of enrollment or lack of commitment to aggressive treatment by family/medical team (e.g., likely to withdraw life support measures within 24 hrs of screening)
8. female who is pregnant or lactating (negative serum or urine pregnancy test results within 48 hours of enrollment or to be performed during screening)
9. prisoner
10. known participation in an interventional research study within 30 days prior to enrollment (note: to be eligible, any interventional treatment must have ended at least 30 days ago)
11. Individuals who are directly affiliated with sponsor or study staff, or their immediate families. Immediate family is defined as spouse, domestic partner, parent, child, or sibling whether legally adopted or biological.
12. Any patient that is deemed unfit for study participation, per the Investigator's discretion.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Exhaled Breath; Exhaled breath samples will be collected 6 times per day and blood samples will be collected once per day for 7 days. Subjects will be followed for an additional 3 days. We will use the Isomark Canary™ to determine the BDV of breath samples collected during this study. Analysis results of these samples will be combined with data that is abstracted from the subjects' medical records.

Device: Isomark Canary™; Isomark, LLC is a Madison, Wisconsin-based company that has developed an investigational device, the Isomark Canary™, that is intended to determine the breath delta value of breath samples collected from critically ill patients.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Breath Delta Value	The variation in breath delta value was assessed regardless of infection status. Exhaled breath samples were collected from participants upon enrollment and every four hours thereafter until the end of the subject's study duration per protocol. Each subject was used as its own control for the purpose of trend analysis.The first breath sample collected was considered an individual's "baseline" sample. The change in the breath delta value was calculated from this baseline sample.	Baseline to ICU discharge or 7 days, whichever came first

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With an Infection Diagnosis	Daily analysis infection status from blood samples given from each participant.	Days 1 through 7

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Positive and Negative Predictive Value of BDV for Infection Diagnosis	Based on an ROC analysis the optimal cutoff value for indicating the presence of infection using the BDV is 1.4‰. Based on this cutoff value the sensitivity and specificity were calculated. Sensitivity, or the true positive rate, is the proportion of actual positives that are correctly identified. In this case, the sensitivity is the percentage of people who have an infection and were identified by the Isomark Canary as having an 'infection'. The specificity, or the true negative rate, is the promotion of actual negatives that are correctly identified as negative. In this case, the specificity is the proportion of people without infections that were correctly classified by the Isomark Canary as having 'no infection'.	7 days

Collaborators and Investigators

• Sponsor: Isomark, LLC
• Collaborators: University of Colorado, Denver; Washington University School of Medicine; University of Florida; Ohio State University

Publications and helpful links

General Publications

• O'Rourke AP, Buckman SA, Evans DC, Kerwin AJ, Breunig EA, Butz DE. Changes in exhaled 13CO2/12CO2 breath delta value as an early indicator of infection in intensive care unit patients. J Trauma Acute Care Surg. 2019 Jan;86(1):71-78. doi: 10.1097/TA.0000000000002097.

Study record dates

Study Major Dates

• Study Start: April 1, 2015
• Primary Completion (Actual): December 1, 2017
• Study Completion (Actual): December 1, 2017

Study Registration Dates

• First Submitted: December 23, 2014
• First Submitted That Met QC Criteria: December 23, 2014
• First Posted (Estimate): December 30, 2014

Study Record Updates

• Last Update Posted (Actual): January 3, 2019
• Last Update Submitted That Met QC Criteria: December 10, 2018
• Last Verified: December 1, 2018

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Infections
• Other Study ID Numbers: Canary01