Breath Analysis Enables Precise Anesthesia Dosing in Children Undergoing Surgery

By HospiMedica International staff writers
Posted on 04 Jun 2025
Image: A patient’s breath from the sample bag being pushed into a mass spectrometer to analyze the metabolites in the exhaled air (Photo courtesy of University of Basel)

Achieving the right dose of anesthetic during surgery, especially in children, is a delicate balancing act. Current methods rely on indirect indicators like vital signs or processed brain activity, but these do not accurately reflect how much of the drug reaches the brain. Now, researchers have developed a breath analysis technique that can help anesthesia teams monitor the concentration of the common anesthetic propofol in near real time, offering a promising new approach to precise and individualized dosing.

This breakthrough by researchers at University of Basel (Basel, Switzerland), along with collaborators, leveraged advanced mass spectrometry and specially designed breath collection systems to monitor the concentration of propofol and its metabolic byproducts. Propofol is a volatile compound, making it particularly suitable for detection in exhaled breath. The researchers used mixed-gas plastic bags to collect breath samples, which were then analyzed in the lab. Although the device used for analysis is too large for operating room use, the setup enabled a detailed evaluation of drug levels throughout surgery. In a pilot study involving ten children undergoing surgery for various reasons, the researchers collected breath and blood samples every 30 minutes before and during anesthesia. According to the findings published in the journal Anesthesiology, the breath test results showed a strong correlation with blood concentrations of propofol, confirming the method’s accuracy.

Notably, breath analysis also revealed biochemical markers of oxidative stress, offering a broader view of the body’s response to anesthesia and surgery. This approach provides a significant improvement over traditional blood tests, which are too slow for real-time monitoring in the operating room. By enabling immediate insights into drug levels and physiological stress, the technique could help anesthesiologists fine-tune doses more precisely, reducing the risk of over- or under-dosing, especially in pediatric patients, where dosing is more complex. Beyond anesthesia, the method shows broader potential in drug monitoring and chronic disease management. Prior studies by the team demonstrated the ability to detect epilepsy medications and their breakdown products in breath samples, helping guide optimal dosing. In a different study, the team also used breath analysis to monitor children with diabetes during hospitalization.


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