There are many traditional efforts to reduce waste of resources in hospitals in general and in ICU:

More specifically in critical care nephrology, the most remarkable way to avoid waste production is Prevention. In medicine, prevention is key for reducing resource use and waste production (15). The highest saving of resources comes from the absence of need to use. In critical care nephrology preventing AKI and reducing progression to severe stages requiring RRT is arguably the most effective sustainability strategy (16, 17).

Beside classical prevention strategies described elsewhere, artificial intelligence (AI) and machine learning (ML) tools have shown promise in predicting AKI development, allowing for timely interventions that preserve kidney function and reduce the need for resource-intensive therapies (18–20).

Predictive AI models, using real-time electronic health record data, can identify patients at risk for AKI with high sensitivity, supporting targeted preventive strategies. By reducing RRT demand, AI contributes indirectly to lowering the ICU’s environmental footprint, while improving patient outcomes (21).

When AKI is already severe and requires RRT, dynamic adjustment of CRRT and IHD doses, based on evolving patient needs (vg adjusting doses, dialysate fluid rate, time of therapy). Personalization of RRT reduces volume of replacement fluid use and associated waste (water, plastic bags, carbon footprint of transportation of fluids, etc) without compromising care quality (8, 11, 22).

Although not always feasible, some elements can be reused, for example fabric coats, scrubs or hats and to avoid single use plastic non-recyclable clothes. Despite the reduction of plastic non-reusable waste, it implies the use of water for washing and sterilizing when needed.

In CRRT there is the opportunity of minimizing some plastic waste by reusing effluent bags within the same session after proper drainage. At an average CRRT dose of 25 mL/kg/h, the effluent requires 6–7 bags per day. Reusing those bags allows the number of bags to diminish to 1–2 per day.

In 2012, the United States produced approximately 31.75 million tons of plastic waste, but only 8.8% of that amount was recycled. This level of recycling translates into a reduction of greenhouse gas emissions equivalent to removing about 670,000 cars from the roads each year, or 3.2 million metric tons of CO₂ emissions avoided (23).

Many recyclable plastics used in catheter implantation or in CRRT or HDI settings are not in contact with the patient or his environment. Discarding those clean elements in adequate recycle bins permit it to be recycled in adequate local centers (9, 12) and diminish the amount of incinerable waste from contaminated bins (24). (See table 1) The use of incineration for health care wastes has an enormous ecological impact due to the production of dioxins, furans, and co-planar polychlorobiphenyls (PCBs) in the process. Those subproducts of combustion are toxic and hazardous when not managed properly (25).

Recyclability depends on kind of material and epidemiological risks associated with the waste. Is crucial to know what kind of plastic fonts can be recycled.

Although hemodialysis filters and tubing are exposed to the patient’s blood and should be classified as hazardous waste requiring incineration, some initiatives—such as that of the non-governmental organization Health Care Foundation in Nepal—have implemented recycling of these components after autoclave disinfection. This strategy is promising; however, it requires adequate resource availability and entails the use of water and electricity, both of which must be carefully assessed (14).

To increase the chance of adequate recycling of clean products like paper and plastics, an initiative should be having a recyclable waste collection bin available at the moment of the procedures of setting on CRRT and catheter insertion, but is mandatory to learn about those susceptible to recycle materials (24) (Figure 1).

Critical care nephrology uses different kind of dialysis machines. Its appropriate maintenance and repairing are a way to avoid discarding technology that is a source of contamination of soils and water (26, 27).

Repairing and relocating machines can be more cost-effective than purchasing new ones, especially in resource-limited settings (28).

When technology becomes obsolete, the relocation of old functioning machines is advisable, for example donation to developing centers without better available technology.

Adoption of high-efficiency devices and exploration of renewable energy sources for dialysis equipment is a pending area.

The implementation of Green ICU and critical care nephrology initiatives is crucial for protecting human health, the environment, and reducing economic costs (4–6). Such strategies should involve all personal in the hospital, including administrative areas to coordinate and effectively complement all processes (29, 30).

It is crucial to ensure that healthcare personnel is trained in proper waste management, including associated risks, disposal practices, and minimization, dynamically adjusting processes based on periodic audit with measurable results to assess compliance with waste management norms and procedures (12, 25).

For critical care nephrology, it is time to imagine new strategies, challenge the processes and design alternative sustainable ways to perform changes in daily practice. It is mandatory for the actual generation of nephrologists to redesign the way that medicine is performed, breaking out the resistance to change and the Semmelweis reflex. Historically, prompt acceptation and adaptation to the new circumstances have proven better outcomes.