Smelling Sepsis with Electronic Nose (eNose) Technology

SUMMARY:

  • Microorganisms can release volatile organic compounds (VOCs) released through exhaled air, producing unique odors.

  • Exhaled breath analysis is a likely and promising alternative to disease detection.

  • eNose measurements can identify sepsis among patients with a suspected infection.

REVIEW:

  • Human exhaled air contains trace amounts of VOCs.

  • A Breath Biopsy can determine VOCs from exhaled air.

  • Over 3,000 VOCs have been identified in breath samples.

  • VOC offers a good alternative to current infection identification.

    • VOC has high accuracy and precision to predict presence of bacterial and fungal organisms.

    • VOC assessments have the potential for large scale early diagnosis and long term monitoring of effectiveness.
    • VOC clinical uses include:
      • Early cancer screening
      • Pneumonia
      • Upper respiratory tract infections
      • Diabetes mellitus
      • Bacterial Pathogens
    • VOC measurement options:
      • Mass spectrometry
      • Gas chromatography
      • Cavity Ring-Down Spectroscopy
      • All are expensive, hard to operate and not portable.
    • eNose VOC analysis:
      • Breath sample obtained
      • Sample exposed to multiple specific sensor array for precision detection
      • Pattern recognition algorithm to detect identity and quantity of various gases/odors
      • Advantages:
        • Low technical cost
        • Excellent discriminating capabilities
        • Miniaturization
        • Simple operation
        • Easy integration
      • Challenges:
        • Performance accuracy over time may diminish due to deviation of algorithm over time
    • Sensors include:
      • Chemical Resistance Sensors
      • Piezoelectric sensors
      • Electrochemical Sensors
      • Optical Sensors
  • Breath Biopsy VOC can distinguish various infections from bacteria, viruses and fungi with high accuracy and precision. 
    • 161 VOCs significantly produced in neonates and infants with sepsis.
  • The Smell of Sepsis
    • Van der Aart et al American Journal of Emergency Medicine 202588:126-133
    • 160 Emergency Department patients
    • Correctly classified sepsis in ~70% of cases
    • AUC 0.78 vs NEWS2 AUC of 0.55
    • Sensitivity 72%
    • Specificity 73%
    • PPV 58%
    • NPV 84%

CONCLUSIONS:

  • In the pursuit of rapid sepsis identification, electronic nose technology is evolving as a possible clinical application.

  • The widespread application of eNose, including sepsis, appears to be inherently safe, noninvasive and convenient.

  • Further development and validation of the eNose system is required at this point.

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Erkan Hassan is the Co-Founder & Chief Clinical Officer of Sepsis Program Optimization where he designs & oversees the implementation of solutions to optimize sepsis programs.

To discuss your organization’s Barriers of Effective Sepsis Care, contact Erkan by phone (844) 4SEPSIS (844-473-7747), email (erkan@spo.icu), or video chat.