Breathe Easier: New Algorithm Improves Oxygen Therapy Monitoring
"A flow-leak correction algorithm enhances the accuracy of work-of-breathing measurements during high-flow nasal cannula oxygen therapy, ensuring better respiratory support."
High-flow nasal cannula (HFNC) therapy is a prevalent method for treating respiratory failure, delivering a heated and humidified oxygen/air mixture at high flow rates to improve ventilatory efficiency and reduce the work of breathing (WOB). However, accurately measuring WOB during HFNC therapy has been technically challenging due to the continuous unidirectional flow toward the patient.
A recent study introduces a novel method for measuring WOB based on a differential pneumotachography (DP) system, which uses pneumotachographs inserted into the HFNC circuit and connected to a monitoring facemask. The key innovation is a leak correction algorithm (LCA) that addresses flow measurement errors caused by leakage around the monitoring facemask. This algorithm ensures more precise readings of respiratory flow and volume, essential for calculating WOB.
The study's findings suggest that this new system, combining DP with LCA, offers a reliable way to monitor respiratory effort during HFNC therapy, potentially leading to more personalized and effective respiratory support strategies. This article delves into the specifics of the algorithm, its validation, and its potential impact on patient care.
Monitoring During Oxygen Therapy
Respiratory monitoring is considered mandatory during the initial stage of acute in-hospital oxygen therapy because a patient's condition may worsen journals.sagepub.com. A 2022 systematic review and meta-analysis examined wearable and contactless devices that measure heart rate, respiratory rate, and oxygen saturation in hospital inpatients, including sleep-study clinics associationofanaesthetists-publications.onlinelibrary.wiley.com. The review was conducted as part of PATH's SOURCE project, which aims to improve equitable access to respiratory care. Pulse oximeters are commonly used to monitor oxygen saturation, while plethysmographs are commonly used to track respiratory rate; both can support remote care when equipped with Bluetooth.
Assessment and Measurement
An oxygen clinical practice guideline describes its purpose as using common assessment criteria to align and adjust oxygen therapy for safe, effective, individualized care utoledo.edu. One measurement approach for work of breathing during high-flow nasal cannula therapy combines two pneumotachographs—one in the HFNC circuit and one connected to a monitoring facemask—with a leak correction algorithm to address flow-measurement errors caused by leakage around the mask doi.org. Pulse oximetry is described as a simple technology used for continuous monitoring across hospitals, clinics, and home care, though the source notes that understanding its limitations is important. The supplied sources do not specify those limitations.
Milestones in Oxygen Monitoring
Clinical oxygen monitoring has used oxygen's effects on hemoglobin color, its concentration in gas, its pressure in blood or tissue, and infrared light through the scalp and skull sciencedirect.com. The effect of oxygenation on hemoglobin color was discovered in 1860, used in a human hand in 1875, and used in a human ear in 1935; Glen Millikan made the method practical in 1942. Supplemental oxygen is now described as vital in prehospital and hospital trauma care, anesthesia, respiratory distress, and other acute and chronic conditions pmc.ncbi.nlm.nih.gov.
How the Flow-Leak Correction Algorithm Works
The core challenge in measuring WOB during HFNC therapy lies in the constant flow of air, which can throw off traditional pneumotachography measurements. The LCA is designed to correct these inaccuracies by accounting for leaks around the monitoring facemask. The system uses two pneumotachographs: one in the HFNC circuit (PNT-A) and another in the monitoring facemask (PNT-B).
- Pressure-based Leak Correction (P-LCA): Uses the pressure inside the facemask to estimate and correct for flow leaks. This method is more robust to changes in mask position or breathing patterns.
- Flow-based Leak Correction (F-LCA): Relies on flow measurements to estimate leaks, simplifying the algorithm by avoiding the need for pressure measurements.
HFNC and Oxygen Targets
A study titled “Real-Time Optimal Flow Setting and Respiratory Profile Evaluation in Infants Treated with High-Flow Nasal Cannula (HFNC)” reports that its algorithm requires monitoring inputs for both Fvent and Fmask doi.org. A separate review of oxygen therapy and noninvasive respiratory support in acute care says supplemental oxygen should be guided by SpO₂ monitoring, with a target above 92% and below 98% sciencedirect.com. That review says noninvasive respiratory supports are generally reserved for the most hypoxemic patients, with the aim of relieving dyspnea.
Recognizing Oxygen-Therapy Problems
A systematic review published in 2023 set out to identify problems related to oxygen therapy in hospitalized adults and classify them using an expert panel and the Pharmaceutical Care Network Europe framework researchgate.net. Another paper, dated June 6, 2022, focuses on analyzing causes of problems in clinical oxygen inhalation therapy and identifying countermeasures in nursing practice researchgate.net. The supplied summaries describe these investigations' aims but do not report specific problem categories, findings, or failure rates.
Wearable and Remote Monitoring
A 2022 systematic review and meta-analysis evaluated wearable and contactless devices measuring heart rate, respiratory rate, and oxygen saturation in clinical settings, including hospital inpatients and sleep-study clinics associationofanaesthetists-publications.onlinelibrary.wiley.com. A 2024 review surveys wearable and remote respiratory-monitoring technologies, ranging from traditional chest belts to newer alternatives, and discusses their potential for continuous and proactive healthcare mdpi.com. The supplied summaries establish that these sources examine different monitoring technologies, but do not provide comparative performance results between them.
The Future of Respiratory Monitoring
The development and validation of this flow-leak correction algorithm represent a significant step forward in respiratory monitoring during HFNC therapy. By accurately measuring work of breathing, clinicians can better assess the effectiveness of respiratory support and make more informed decisions regarding flow rate adjustments.
Prescription, Documentation, and Monitoring
A source on evaluating oxygen therapy in inpatient care describes safety and efficacy as depending on appropriate prescription, accurate documentation, and continuous monitoring afjbs.com. Its summary says international guidance from the British Thoracic Society (BTS), American Association for Respiratory Care (AARC), and World Health Organization (WHO) emphasizes titrated oxygen delivery with defined parameters. A separate 2025 source reports that F695 Respiratory Care remained among the ten most frequently cited deficiencies nationwide in the 2025 survey year for skilled nursing facilities proactiveltcexperts.com.
Questions About Continuous Oximetry
Continuous pulse oximetry has been used for decades in systems designed to recognize patient deterioration onlinelibrary.wiley.com. A 2026 source frames an ongoing question around how effective this approach is for patients receiving supplemental oxygen. The supplied summary introduces the issue but does not provide findings or a conclusion about effectiveness.
Monitoring Beyond the Bedside
Tarassenko’s group was the first in the world to report non-contact monitoring of changes in oxygen saturation using ambient light and a single video camera, in 2014 results2021.ref.ac.uk. A review of home oxygen monitoring and therapy describes programmes established around the world during the pandemic, mostly in high-income countries, to support early detection of hypoxaemia and/or early hospital discharge ovid.com. A 2025 book chapter says oxygen saturation can be predicted from wearable sensor data using machine-learning techniques link.springer.com.
While the study demonstrates the algorithm's effectiveness in controlled settings, further research is needed to evaluate its performance in diverse patient populations and clinical scenarios. Future studies could also explore the integration of this technology into user-friendly monitoring devices, making it more accessible to healthcare providers.
Ultimately, this advancement paves the way for more personalized and effective respiratory care, optimizing patient outcomes and improving the management of respiratory failure. With precise monitoring of patients in need, medical practitioners would have greater insight and a more optimized respiratory plan.