Faculty Bibliography

Waste auditing is important for effectively reducing the medical waste generated by resource-intensive operating rooms. To replace the current time-intensive and dangerous manual waste auditing method, we propose a system named iWASTE to detect and classify medical waste based on videos recorded by a camera-equipped waste container. In this pilot study, we collected a video dataset of 4 waste items (gloves, hairnet, mask, and shoecover) and designed a motion detection based preprocessing method to extract and trim useful frames. We propose a novel architecture named R3D+C2D to classify waste videos by combining features learnt by 2D convolutional and 3D convolutional neural networks. The proposed method obtained a promising result (79.99% accuracy) on our challenging dataset.Clinical Relevance-iWaste enables consistent and effective real-time monitoring of solid waste generation in operating rooms, which can be used to enforce medical waste sorting policies and to identify waste reduction strategies.

BACKGROUND: Environmental sustainability is a growing concern to healthcare providers, given the health impacts of climate change and air pollution and the sizable footprint of healthcare delivery itself. In 2017, 17.9% of the United States (US) Gross Domestic Product, or $3.5 trillion, was from the healthcare sector (1). In addition,10% of US greenhouse gas emissions (GHGs) and 9% of air pollutants that adversely affect the lives of the public(2,3) come from the healthcare sector. Though many studies have focused on environmental footprints of operating rooms, few have quantified emissions from inpatient stays.
METHOD(S): This study analyzes resources required for care activities of a regular inpatient unit (Unit 4500) with 49 beds and 14,427 bed days and a medical intensive care unit (MICU) with 12 beds and 2,536 bed days in a tertiary, private hospital in Brooklyn, NY, USA. Through the use of hybrid Environmental Life Cycle Assessment (LCA), average emissions associated with resource use in an inpatient setting for one calendar year and per bed day were quantified. Retrospective data collected included purchasing of supplies, pharmaceutical, utilities (gas, water, electricity), and linens used over a calendar year, and staffing levels in both units. A 5-day period of manual waste auditing in each unit was also conducted.
RESULT(S): Unit 4500 generates 5.5kg of solid waste and 65kg CO2-e per bed day, shown in the Figure. The MICU generates 7.1kg of solid waste and 168kg CO2-e per bed day. Most emissions originate from purchase of consumable goods, building energy consumption, purchase of capital equipment, food services, and staff travel.
CONCLUSION(S): As expected, the MICU generates more solid waste and GHGs per bed day than Unit 4500. With resource use and emissions data, sustainability strategies, like energy efficiency upgrades, renewable energy sources, minimizing single-use consumables, and optimizing care pathways, can be effectively targeted and tested. Medical device and supply manufacturers should also aim to minimize life cycle waste and GHGs.(Figure Presented)

In an online survey of more than 1300 cataract surgeons and nurses, 93% believed that operating room waste is excessive and should be reduced; 78% believed that we should reuse more supplies; 90% were concerned about global warming; and 87% wanted medical societies to advocate for reducing the surgical carbon footprint. The most commonly cited reasons for excessive waste were regulatory and manufacturer restrictions on reuse or multiple use of devices, supplies, and pharmaceuticals. More than 90% believed that profit, liability reduction, and failure to consider carbon footprint drive manufacturers to produce more single-use products; more than 90% want more reusable products and more regulatory and manufacturer discretion over when and which products can be reused. Assuming comparable cost, 79% of surgeons preferred reusable over disposable instruments. In order of decreasing consensus, most were interested in reusing topical and intracameral medications, phacoemulsification tips, irrigating solutions/tubing, blades, cannulas, devices, and surgical gowns.

Background: The healthcare sector contributes 10% of US greenhouse gas emissions (GHGs). Given the adverse health effects associated with GHGs, healthcare sector workers have a moral imperative to reduce these GHGs. Life Cycle Assessment (LCA) is a tool used to quantify environmental emissions associated with a product or process, including natural resource extraction, manufacturing, packaging, transportation, use, and disposal of materials. To quantify GHGs and help guide pollution prevention strategies, we applied LCA to the process of preparing a biopsy in a surgical pathology laboratory.
Design(s): A detailed analysis of the processing of a biopsy was performed at a large surgical pathology laboratory, and grouped into 11 steps. Each supply item, reagent, and capital equipment was catalogued, along with the number of individuals involved, and average duration of each step. Supply items were weighed and primary material types noted. The lifespan of each reusable item was estimated, and post-use treatment pathways, including disposal, were noted. Reagent quantity was allocated to a single case based on total bottles used in the lab over one week. Watt meters and equipment power ratings were used to estimate the energy consumption of capital equipment. A lifecycle inventory and impact analysis were performed to estimate GHGs. The LCA was performed comparing two scenarios as a sensitivity analysis: (1) a patient case with a single biopsy jar and (2) a patient case with three biopsy jars.
Result(s): The largest proportion of total GHGs was from processing the cassette(s) on the tissue processor (Leica ASP 300S), which contributed 0.085kg of CO2-equivalents (kg CO2e) for scenario 1 and 0.224 kg CO2e for scenario 2, or, in both scenarios, 31% of total emissions, of which 25% was attributable to production of reagents used. The second largest contributor to GHGs was receiving and accessioning the case in the lab, which contributed 0.051kg CO2e or 19% of total emissions in scenario 1, and 0.151kg CO2e or 21% of total emissions in scenario 2, attributable mostly to the jars being single use items. Sensitivity analysis showed that GHGs can range between -18% and +4% for scenario 1, and between -15% and +10% for scenario 2.
Conclusion(s): This study evaluates the processing of a surgical pathology biopsy using an LCA. Understanding the process steps that contribute to GHGs is essential for determining which parts of the healthcare sector could be effectively targeted for reducing emissions

Purpose: Eyefficiency is a cataract surgical services auditing tool that aims to help units worldwide improve their surgical productivity and reduce their costs, waste generation, and carbon footprint. Phase 1 pilot tested in India, UK and Africa in 2017; while Phase 2 had two rounds of beta testing with sites participating from 6 WHO/IAPB regions.
Method(s): Eyefficiency has been through 3 rounds of testing, pilot tests at 4 sites in 2017 and two rounds of beta testing with sites from 6 WHO/IAPB regions in 2018-2019. Test sites entered facility-level data (staffing, pathway steps, costs of supplies, and energy use) on the Eyefficiency website. They entered time-and-motion data on Eyefficiency app from 30 consecutive cases or 1 week of cataract surgery. Eyefficiency uses descriptive statistics and environmental Life Cycle Assessment (LCA) to quantify productivity, costs, and carbon footprint.
Result(s): Eyefficiency testing was completed by 10 surgical facilities (in Swaziland, Chile, South Africa, Mexico (2), Guatemala, New Zealand, India, UK, and Hungary). Per bed case duration ranged from 13 minutes to 73 minutes with the majority of the time at all sites spent operating. Cases per hour ranged from 0.9 to 4.5. A majority of costs appear to come from the purchasing pharmaceuticals, disposable surgical supplies and energy; while carbon emissions appear to come largely from manufacturing of supplies and transportation.
Conclusion(s): Results show variability in cataract surgery efficiency metrics across the world, with lessons to be learnt from sites with higher throughput, lower costs, and reduced resource use

Purpose: Operating theatres are some of the most energy and resource intensive areas for medical treatment. As a result of resource production, use, and disposal, emissions are generated that harm the environment and human health. New tools are emerging to quantify these emissions and this study seeks to understand the footprint of cataract surgery at a US facility and to identify opportunities for reducing emissions.
Method(s): Eyefficiency, a new international cataract surgical services auditing tool that enables carbon emission calculations per surgical case, was used to quantify associated greenhouse gas (GHG) emissions in terms of kilograms of carbon dioxide equivalents (kg CO2e) for cataract surgeries conducted in an outpatient centre in the US. These include emissions from supplies, energy, and reusable instruments in an average case. This site also conducted audits of pharmaceutical waste disposal to determine the quantity of unused and wasted products at the end of an average case.
Result(s): Preliminary Eyefficiency data shows that a majority of this sites' GHG emissions from cataract surgery are generated from procurement (production) of single use products and pharmaceuticals, electricity used in the operating theatre, and travel of staff. Of GHGs from pharmaceutical production, 60% can be attributed to unused drugs that are disposed of after the case.
Conclusion(s): There are many avenues available to reduce resource consumption and GHG emissions from cataract surgical care, but quantifying and understanding the sources of emissions is an important first step