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.1
• -- 61 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.

Erkan Hassan, Pharm.D., FCCM is a transformational healthcare leader with extensive experience developing innovative solutions to improve clinical outcomes, enhance provider experience and increase revenue.

You can reach Erkan at [email protected]