Unleashing the Economic Potential of Sustainable Cath Labs
Interventional cardiology and electrophysiology labs rely heavily on energy-intensive angiography imaging systems. While efforts are underway to "green" these systems by reducing their energy consumption during procedures, a significant opportunity for energy savings often overlooked is simply turning off these systems overnight when they are not in use. This not only contributes to environmental sustainability by reducing carbon emissions but also translates into substantial cost savings for cardiology departments through lower electricity bills.
Unlike household appliances with clear energy efficiency ratings (like Energy Star), angiography systems lack standardized metrics for comparing energy consumption and costs. To address this gap, researchers at University Hospital Basel in Switzerland conducted a study to quantify the energy usage of their seven Siemens fluoroscopy systems across various departments (cardiology, interventional radiology, neurointerventional radiology, and urology).
The study, published in the American Journal of Roentgenology (https://ajronline.org/doi/10.2214/AJR.24.30988), aimed to determine the actual energy consumption, associated costs, and carbon emissions of these systems. Furthermore, the researchers investigated the potential cost savings achievable by powering down these systems completely during periods of inactivity, rather than keeping them running 24/7.
Dr. Jan Vosshenrich, a consultant radiologist at University Hospital Basel and a postdoctoral research scholar at NYU Langone Health, and his team found that a simple operational adjustment – powering down all angiography systems overnight and on weekends instead of keeping them in idle mode 24/7 – could yield substantial benefits.
Their research, published in the American Journal of Roentgenology, estimated that this change could lead to:
- Annual energy savings of 144,640 kilowatt-hours (kWh)
- Carbon emissions reduction of 18.6 metric tons of CO2 equivalent (MtCO2eq)
- Electricity cost savings of $37,896
These findings highlight the significant potential for energy conservation and cost reduction in healthcare settings by optimizing the operation of high-energy consuming medical equipment.
Study Methodology and Findings:
- Traditional Estimation: Energy consumption of interventional imaging systems is typically estimated based on manufacturer specifications, not actual usage.
- University of Basel's Practice: The hospital has a long-standing policy of powering down imaging systems at the end of each workday, with the exception of emergencies. This allowed for direct comparison between actual energy consumption and the potential consumption if systems were left in idle mode.
- Data Collection:
- Radiology and Cardiology: Power sensors were installed on these systems in 2018. Data was collected for four weeks in 2022.
- Urology: Power sensors were installed temporarily for two weeks in summer 2023.
- Energy Consumption:
- Total Consumption: The seven systems combined consumed an estimated 115,684 kWh annually, equivalent to the energy used by 23 average households.
- System-Level Consumption:
- Radiology and Cardiology: Each system's annual consumption was comparable to four to five average households.
- Urology: Each system's annual consumption was comparable to one average household.
- Idle Mode Impact:
- Significant Contribution: Surprisingly, if these systems were left in idle mode 24/7, as is common practice in many hospitals, off-hour power consumption would have accounted for a substantial 60.3% of the total energy consumption.