Medical and technical activities have a significant environmental impact. Various national recommendations and local initiatives aim to reduce it, but it remains difficult to identify which changes in patient pathways can most effectively lower emissions without compromising quality of care. To help prioritize potential measures, we analyzed all possible colonoscopy pathways to develop a digital comparative tool assessing the environmental impact of different care scenarios.

Interviews were conducted with engineers, clinical teams, and support staff (administrative, logistics, pharmacy, sterilization, biomedical, etc.) to map every step of the colonoscopy process (outpatient, day-case, and inpatient). The analysis included the preparation phase (scheduling, medical visits, bowel preparation), the procedure itself (anesthesia type, endoscope and accessories, consumables, procedural steps achieved), and the post-procedure phase (disinfection, patient recovery, sample management, waste processing, follow-up).

For each step, the carbon footprint of alternative practices was calculated (e.g., general vs local anesthesia, CO₂ insufflation vs water irrigation, reusable (RU) vs single-use (SU) accessories, digital data storage methods etc..). A simplified life cycle assessment (LCA) was performed using the CAREBONE™ tool developed by AP-HP (open source, video abstract), expressing greenhouse gas emissions in kgCO₂e. We will aggregate this data into a digital tool allowing users to explore each step of the care pathway, quantify its total carbon impact, and assess the CO₂e difference associated with any modification.

Calculation of an illustrative colonoscopy pathway including the following main steps was performed. Carbon emissions (KgCO₂e) are reported when available for each step.

- Pre-Endoscopy: A remote pre-anaesthetic consultation (0.078); standard bowel preparation (0.51); patient dressing with single-use pyjamas (0.79); reusable bedsheets (0.032) with single-use bed protection (0.25)

- During-Endoscopy: Propofol-based deep sedation (9.98); use of a reusable endoscope (3.39) and its associated components (1.52) (aspiration and insufflation tubing, pistons, sterile water for the water-jet system); CO₂ insufflation (0.078); use of a polypectomy snare (0.36) and formol biopsy tube (0.48); disposal of liquid waste (0.29); protective equipment for the endoscopist (0.56)

- After-Endoscopy: Endoscope reprocessing (1.30) including nurse protective gear, manual pre-cleaning, and disinfection in automated endoscope reprocessor, drying and storage; Patient recovery with a light snack and a SU water bottle (0.37).

Under this pathway, total CO₂ emissions of a signle colonoscopy was 20KgCO₂e. Highest CO₂-emitting sectors were anasthesia, SU devices and endoscope reprocessing. Patient transport was excluded from the initial analysis as many tools already exist to estimate their burden (For instance, 30km drive in a petrol car would add 6.53Kg CO₂e)

Our study aimed to identify the key steps in the patient pathway where professionals in an endoscopy unit can directly influence the reduction of the environmental footprint by implementing targeted measures. Our digital tool will provide healthcare facilities with a simple and interactive way to (re)organize their workflow, thereby minimizing the environmental footprint of colonoscopy.