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L-ficolin is a serum lectin synthesized (as a ~37 kDa polypeptide) predominantly by the liver, and is one of the key molecules of the innate immune system. It has an amino (N)-terminal cysteine-rich region, a middle stretch of a collagen-like sequence, and a fibrinogen-like domain in the carboxy (C)-terminus. Three identical polypeptides form a structural (triple helical) subunit, with the help of the collagen-like domain. Further oligomerization of this subunit results in different sized L-ficolin molecules (from dimers to tetramers) in circulation. However, the tetrameric form (composed of 12 polypeptides) is the most prevalent structure. The polypeptides in the structural subunit are cross-linked by disulphide bonds in the N-terminal region. The fibrinogen-like domain forms a globular structure. The overall structure of oligomeric L-ficolin closely resembles mannose-binding lectin (MBL). Similar to MBL, L-ficolin also acts as a pattern recognition receptor. It primarily recognizes acetylated sugar residues on the cell surface of different gram-positive and gram-negative bacteria, viruses and other pathogens. There are two pathways by which L-ficolin may participate in a host defense response: 1) It activates the complement lectin pathway, via MBL/ficolin associated serine proteases (MASPs), that converges with the classical complement pathway at the level of complement C4, and 2) it may also act directly as an opsonin, enhancing phagocytosis by binding to cell-surface receptors present on phagocytic cells. M-ficolin and H-ficolin are structurally similar to L-ficolin. However, they differ in their tissue expression and binding affinities to pathogenic ligands.

Introduction: Healthcare contributes 10% of greenhouse gases in the United States and generates two milion tons of waste each year. Reducing healthcare waste can reduce the environmental impact of healthcare and lower hospitals’ waste disposal costs. However, no literature to date has examined US emergency department (ED) waste management. The purpose of this study was to quantify and describe the amount of waste generated by an ED, identify deviations from waste policy, and explore areas for waste reduction.

Methods: We conducted a 24-hour (weekday) ED waste audit in an urban, tertiary-care academic medical center. All waste generated in the ED during the study period was collected, manually sorted into separate categories based on its predominant material, and weighed. We tracked deviations from hospital waste policy using the hospital’s Infection Control Manual, state regulations, and Health Insurance Portability and Accountability Act standards. Lastly, we calculated direct pollutant emissions from ED waste disposal activities using the M+WasteCare Calculator.

Results: The ED generated 671.8 kilograms (kg) total waste during a 24-hour collection period. On a per-patient basis, the ED generated 1.99 kg of total waste per encounter. The majority was plastic (64.6%), with paper-derived products (18.4%) the next largest category. Only 14.9% of waste disposed of in red bags met the criteria for regulated medical waste. We identified several deviations from waste policy, including loose sharps not placed in sharps containers, as well as re-processable items and protected health information thrown in medical and solid waste. We also identified over 200 unused items. Pollutant emissions resulting per day from ED waste disposal include 3110 kg carbon dioxide equivalent and 576 grams of other criteria pollutants, heavy metals, and toxins.

Conclusion: The ED generates significant amounts of waste. Current ED waste disposal practices reveal several opportunities to reduce total waste generated, increase adherence to waste policy, and reduce environmental impact. While our results will likely be similar to other urban tertiary EDs that serve as Level I trauma centers, future studies are needed to compare results across EDs with different patient volumes or waste generation rates.

Background: Delivering healthcare requires significant resources and creates waste that pollutes the environment, contributes to the climate crisis, and harms human health. Prior studies have generally shown durable, reusable medical devices to be environmentally superior to disposables, but this has not been investigated for pulse oximetry probes.

Objective: Our goal was to compare the daily carbon footprint of single-use and reusable pulse oximeters in the emergency department (ED).

Methods: Using a Life Cycle Assessment (LCA), we analyzed greenhouse gas (GHG) emissions from pulse oximeter use in an urban, tertiary care ED, that sees approximately 150 patients per day. Low (387 uses), moderate (474 uses), and high use (561 uses), as well as cleaning scenarios, were modelled for the reusable oximeters and compared to the daily use of single-use oximeters (150 uses). We calculated GHG emissions, measured in kilograms of carbon dioxide equivalents (kgCO2e), across all life cycle stages using life-cycle assessment software and the ecoinvent database. We also carried out an uncertainty analysis using Monte Carlo methodology and calculated the break-even point for reusable oximeters.

Results: Per day of use, reusable oximeters produced fewer greenhouse gases in low-, moderate-, and high-use scenarios compared to disposable oximeters: 3.9 kgCO2e, 4.9 kgCO2e, 5.7 kgCO2evs 23.4 kgCO2e, respectively). An uncertainty analysis showed there was no overlap in emissions, and a sensitivity analysis found reusable oximeters only need to be used 2.3 times before they match the emissions created by a single disposable oximeter. Use phases associated with the greatest emissions varied between oximeters, with the cleaning phase of reusables responsible for the majority of its GHG emissions (99%) compared to the production phases of the single-use oximeter (74%).

Conclusion: Reusable pulse oximeters generated fewer greenhouse gas emissions per day of use than their disposable counterparts. Given that the pulse oximeter is an ubiquitous piece of medical equipment used in emergency care globally, carbon emissions could be significantly reduced if EDs used reusable rather than single-use, disposable oximeters.

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