Sustainability of Laparoscopic Appendectomy. Variability of Determining Factors.

Evidence shows that changes in our environment negatively affect human health, and the burden of a range of climate-sensitive health problems impacts the functioning of public health systems (1). Paradoxically, the healthcare industry itself is a major emitter of pollutants. Hospital processes generate emissions into the air, water, and soil, producing pharmaceutical, chemical, and radioactive waste that increases risks to human health (2). In the USA, the healthcare sector is responsible for 9-10% of greenhouse gas emissions, which represents 614,000 DALYs (disability-adjusted life years) (2). Today, it is clear that protecting human health without ensuring a healthy environment is counterproductive. The 2020 Helsinki Declaration calls for awareness of the strong interrelationship between human and planetary health (3).

Studying the sustainability of healthcare processes presents an opportunity to mitigate their impact. This is defined as a three-pillar concept encompassing economic, social, and environmental dimensions (4). Information on the environmental impact of a process is derived from a life cycle assessment (LCA), which identifies opportunities to improve environmental performance. To date, LCA studies in healthcare include anesthesia equipment and pharmaceuticals, central venous catheters, dental burs, custom-made disposable surgical packs, surgical instruments, medical-grade plastics, hospital gowns and textiles, and radiology equipment. They also include procedures such as childbirth, hysterectomy, hemodialysis and peritoneal dialysis, plastic surgery, cataract extraction, and intensive care, among others (4-6). However, in our review of the environmental impact of medical procedures, we did not find any sustainability studies that incorporated, in addition to LCA, a clinical effectiveness analysis such as DALYs and an economic evaluation of the intervention.

Operating rooms are the most resource-intensive areas in hospitals, with the three main contributors being energy consumption, anesthesia, and product use (4). Appendectomy is one of the most frequently performed surgeries and is associated with significant morbidity, mortality, and costs. Hospitalizations related to appendicitis cost $3 billion annually in the United States alone (5). Laparoscopic appendectomy offers the greatest benefits, with shorter hospital stays and lower perioperative morbidity (6).

Therefore, this project proposes to conduct a sustainability study of laparoscopic appendectomy. The aim is to determine the variability in resource consumption that defines the carbon footprint of each procedure. Understanding this variability will allow for the identification of gaps or practices that can lead to improved sustainability for each procedure, so that for every year of life lost due to disability or death (DALY) avoided by the procedure, it can be performed at the lowest possible cost and with the least possible environmental impact.

General Objective: To estimate the sustainability of laparoscopic appendectomy procedures performed at the Dr. Hernán Henríquez Aravena Hospital in Temuco (HHHA).

Specific Objectives:

1. To update costs and estimate environmental damage and its relationship to effectiveness, as DALYs avoided, in order to calculate and describe the behavior of the Cost-Effectiveness-Impact indicator in laparoscopic appendectomy.
2. To analyze the sustainability of each appendectomy through the Cost-Effectiveness-Environmental Impact indicator, identifying the critical points in their life cycles within the study population.
3. To estimate the harm to human health, in DALYs, generated by the environmental critical points in the life cycles of laparoscopic appendectomies.

Methodology. Design: Quantitative observational study with a prospective longitudinal analytical design. Accessible population: Patients undergoing laparoscopic surgery for acute appendicitis at the HHHA (Hospital Hermanos Aguilera). Sample size: The sample size was determined using criteria from clinical experts, economists, and administrators, estimating 60 cases. Feasibility and Sampling: The study will be conducted in the operating rooms of the HHHA (Hospital Hernando de Apoquinos), from October 2024 to September 2025, allowing 12 months for case recruitment. At HHHA, 1,213 appendectomies are performed annually. Selection will be systematic, consecutive, and non-probabilistic. A 50% loss to follow-up is expected. Inclusion Criteria: 1) Patients scheduled for laparoscopic surgical interventions for acute appendicitis. 2) Participants must be over 18 years of age, competent, and able to easily understand the informed consent form and the characteristics of the study. Exclusion Criteria: 1) Interventions combined with other procedures or surgeries. Data Collection: A coordinating nurse will select consecutive interventions. They will record clinical and demographic data of the patients after they have signed the informed consent form (attached). The use of supplies will be recorded for each intervention from the moment the patient enters the operating room until they leave (system limit). Data not collected directly (costs) will be extracted from the hospital database.

A/P/S: Laparoscopic Surgery for Acute Appendicitis at HHHA. Functional Unit: This is a single intervention, representative of 60 sample interventions. Reference Flow: The application of a specific intervention to a patient. Scope: The scope will consider inputs from cradle to grave for each intervention performed on the patient in the operating room, defining the entry into the reference flow as the patient's arrival in the operating room until their departure (system boundaries). Allocation: Allocation methods based on physical quantity (mass). Information Sources: Electronic hospital records, patient surveys, and literature. Among other things, the following will be recorded: Mass of surgical and anesthetic supplies, waste and its transport from the hospital to the landfill, recycling, and oxygen and CO2 consumption. Electricity consumption will be quantified during the intervention. The impacts of the production and disposal of disposable clothing, and water consumption, will be measured.

Proposed Analysis:

1. Economic Analysis: An update and description of the intervention costs will be performed, including marginal, incremental, and average costs. Direct costs will be estimated using micro-costing techniques. Direct healthcare costs of the health technologies used, such as medications, medical devices, and care provided by healthcare professionals, among others, will be measured and quantified. The labor cost of each professional participating in the interventions will be quantified by measuring the number of minutes worked by each. The total cost of each professional's activity will be estimated based on the number of minutes of work performed, multiplied by the monthly remuneration, and divided by the number of minutes worked per month. Obtaining the costs of infrastructure use (electricity, water, heating, operating room time, operating room fees) used in each intervention: Depreciation of equipment and infrastructure will not be included because the study aims to estimate the environmental impact or sustainability of resource use; therefore, energy and/or supplies will be considered. The costing will have an operational focus.
2. Environmental Impact Analysis: The LCA will be performed using ISO 14040 (2006a) and ISO 14044 (2006b) with the CCALC database and Open LCA software to estimate GHG CO2e emissions. The most significant categories or critical points will be determined, and the resulting damage to human health (DALYs) will be estimated. Life Cycle Inventory: This phase involves compiling and quantifying the inputs and outputs for the given production system throughout its entire life cycle, in order to generate a network of interconnected processes that model the process of each operation. The reference flows will be the basis for calculating each inventory. Electrical energy will be modeled using data from the national electrical grid. Input information will be obtained from the supplier, Ecoinvent, CCALC, or scientific publications. A sensitivity analysis will be performed during the interpretation stage.
3. Clinical Effectiveness Analysis: The clinical effectiveness measure to be used is the DALYs avoided or prevented, as defined in the disease burden study for appendicitis (7). Information on the average DALYs prevented by surgery will be obtained from this study.

Sustainability Results: After updating costs and estimating critical points of environmental damage, the relationship between both and clinical effectiveness, expressed as average DALYs avoided for the study group, will be analyzed. Thus, the Cost-Effectiveness-Environmental Impact indicator for each surgical intervention will be calculated, considering it as the average value of the Cost-Effectiveness-Environmental Impact ratio. This will yield an indicator expressed in Euro/CO2eq/DALYs avoided. This indicator will describe the variability among surgeries. Variability will be calculated by comparing interventions in the first quartile (low environmental impact) versus those above this quartile. We will be able to identify gaps where sustainability can be improved.