IKORUS Catheter Shows Promise for Continuous Perfusion Monitoring in Critical Care

Is the IKORUS Catheter the Future of Critical Care Monitoring?

Vygon's IKORUS catheter demonstrates promising results as a continuous perfusion monitor in critical care, according to new feasibility data. The photoplethysmography-equipped urinary catheter, which measures central tissue perfusion via a Urethral Perfusion Index (UPi), maintained excellent signal quality in intensive care patients and showed correlations with established perfusion markers.

The single-center UK pilot study conducted between November 2023 and August 2024 enrolled 27 critically ill patients requiring urinary catheterization. Researchers replaced standard catheters with the IKORUS device to evaluate its feasibility in measuring tissue perfusion. The study represents the first investigation of the technology in critical care, following earlier validation in surgical settings. The IKORUS catheter incorporates infrared photoplethysmography sensors that detect variations in blood volume at the urothelial level, offering a central measurement of perfusion unlike peripheral alternatives. The device maintained impressively high signal quality throughout more than 300 hours of continuous monitoring, with a median Signal Quality Index (SQI) of 0.93, well above the manufacturer's recommended 0.80 threshold for clinical reliability. No complications related to device insertion were reported, supporting its safety profile.

What Insights Do Perfusion Metrics Provide?

The study found a moderate positive correlation (Spearman's r=0.52, p<0.0001) between UPi and left ventricular outflow tract velocity time integral (LVOT VTi), a validated measure of stroke volume. However, when examining responses to fluid challenges, the relationship between percentage changes in UPi and VTi was weak and not statistically significant. This discordance highlights the complex interplay between macrocirculation and microcirculation, a phenomenon previously observed with other perfusion monitoring technologies. Dr. Iain Mackenzie, principal investigator, noted: "The considerable variability in UPi response to fluid challenges suggests that UPi reflects more than just changes in cardiac output, potentially capturing aspects of microcirculatory function that traditional hemodynamic parameters miss."

When researchers stratified patients based on median UPi values, those with below-median UPi demonstrated significantly worse traditional markers of tissue perfusion, including higher lactate levels (2.8 vs. 1.2 mmol/L, p=0.01) and prolonged capillary refill times (4 vs. 3 seconds, p=0.008). These patients also required higher doses of noradrenaline (0.47 vs. 0.20 mcg/kg/min, p<0.001) and were more likely to need additional vasopressors and inotropes. This suggests UPi might serve as a valuable indicator of perfusion status and potentially help identify patients at risk for persistent hypoperfusion. The IKORUS device offers an advantage over existing microcirculatory monitoring techniques like sublingual videomicroscopy, which require stable conditions and are prone to poor data quality in the dynamic ICU environment. By utilizing a device already standard in critical care (urinary catheter), UPi provides continuous central perfusion data without adding invasiveness.

Key Finding: The IKORUS catheter maintained exceptional signal quality (median SQI of 0.93) during over 300 hours of continuous monitoring in 27 critically ill patients. Patients with below-median UPi values showed significantly worse perfusion markers:

Higher lactate levels (2.8 vs. 1.2 mmol/L, p=0.01)
Prolonged capillary refill times (4 vs. 3 seconds, p=0.008)
Increased vasopressor requirements (noradrenaline: 0.47 vs. 0.20 mcg/kg/min, p<0.001)

This suggests UPi may serve as a valuable early indicator of perfusion status in critical care patients.

Where Do We Go From Here in Perfusion Monitoring?

Despite promising findings, the investigators acknowledge the study's limitations, including its small sample size and exploratory nature. The company plans larger validation studies across multiple centers to establish standardized interpretations of UPi values and explore its potential as a therapeutic target. Future research directions include developing time-weighted averages of UPi metrics and applying machine learning algorithms to predict clinical deterioration before conventional markers indicate problems. Vygon representatives expressed optimism about the technology's potential to address the critical unmet need for reliable, continuous perfusion monitoring in critically ill patients.

Innovation Advantage: Unlike existing microcirculatory monitoring techniques (such as sublingual videomicroscopy) that require stable conditions and are prone to poor data quality in dynamic ICU environments, the IKORUS catheter provides continuous central perfusion monitoring by embedding photoplethysmography sensors into a standard urinary catheter. This approach adds no additional invasiveness while delivering real-time perfusion data, potentially enabling earlier detection of clinical deterioration before conventional markers indicate problems.

How Will Smart Devices Reshape Critical Care?

Industry Context: The IKORUS catheter enters a medical device landscape increasingly focused on minimally invasive continuous monitoring solutions that can detect subtle physiological changes before clinical deterioration becomes evident. With hospitals seeking technologies that enhance early intervention capabilities while integrating seamlessly into existing workflows, Vygon's approach of embedding advanced monitoring into standard care equipment (urinary catheters) aligns with broader industry trends toward "smart" medical devices. As healthcare systems worldwide grapple with critical care resource constraints, technologies that help identify at-risk patients and guide targeted interventions could significantly impact both clinical outcomes and resource utilization.

Summary

The IKORUS catheter by Vygon represents a novel approach to continuous perfusion monitoring in critical care settings. This photoplethysmography-equipped urinary catheter measures central tissue perfusion through a Urethral Perfusion Index (UPi), providing real-time data without additional invasiveness. A UK pilot study involving 27 critically ill patients demonstrated excellent signal quality over 300 hours of monitoring, with the device maintaining a median Signal Quality Index of 0.93. The study found a moderate positive correlation between UPi and established cardiac output measures, though responses to fluid challenges showed more complex patterns. Patients with lower UPi values exhibited significantly worse perfusion markers, including elevated lactate levels, prolonged capillary refill times, and higher vasopressor requirements. Unlike existing microcirculatory monitoring techniques that require stable conditions and are prone to poor data quality, the IKORUS device leverages a standard critical care tool to provide continuous central perfusion data. While the initial feasibility results are promising, larger multicenter validation studies are planned to establish standardized interpretations and explore UPi as a potential therapeutic target. The technology exemplifies the healthcare industry's shift toward minimally invasive, continuous monitoring solutions that integrate seamlessly into existing workflows while potentially enabling earlier detection of clinical deterioration.