A team from the Sydney Children’s Hospitals Network (SCHN) is working to reduce the environmental impact of metered dose inhalers (MDIs or puffers) used to treat children presenting with acute wheeze to the Sydney Children's Hospital, Randwick, while maintaining clinical safety and efficacy.
Although MDIs are a highly effective, safe and low-cost treatment option, they are associated with a significant carbon footprint. This is particularly relevant in paediatric care, where the environmental impact of treatment choices can have long-term implications for the very population we aim to protect. Children are disproportionately affected by climate change, which contributes to their increased risk of respiratory conditions, heat stress and pollution-related illnesses.
Respiratory conditions in children are managed by a medication, Salbutamol (an MDI), with a global warming potential 1430 to 3220 times greater than that of carbon dioxide. Each year, 15.7 million MDIs are distributed across Australia, making up 1.72% of total healthcare emissions.
Dry powder inhalers are a suitable alternative to MDIs, as they are equally effective for most patients and significantly reduce environmental impact due to their propellant-free design. However, they are generally not recommended for children under 6 years old, because younger children often cannot generate the required inhalation flow.
A sustainable, safe respiratory model for children
This project aims to lower healthcare-related carbon emissions, improve asthma management in young children, and provide a scalable model for sustainable respiratory care across the state. It also acknowledges and addresses the absence of a sustainable care pathway for children under 6 years of age, who represent 74% of emergency department (ED) presentations for acute wheeze at the Sydney Children’s Hospital, Randwick.
The project team has identified three strategies to reduce emissions:
- identifying children for preventer therapy (medication that reduces the risk of asthma flare ups)
- reducing reliever use via precision-based dosing
- expanding access to dry powder inhalers for children over the age of 6.
Standardising clinical interventions and reducing waste
This project is a staged implementation initiative.
Phase 1: Clinical interventions (2024 to 2026)
In phase 1, the project team developed three solutions.
- Phenotyping patients – introduce a standardised approach to identify children who would benefit from preventer therapy.
- Risk-adjusted Salbutamol dosing – reduce unnecessary reliever use through precision-based continuation dosing.
- Improved access to dry powder inhalers– expand access for eligible children, particularly those over 6 years.
Quick win: In addition to progressing these solutions, the project team has successfully implemented automated dispensing cabinets. Found at point-of-care locations, these cabinets will streamline medication management and improve inventory control. The cabinets have already reduced wait times for nurses and pharmacists and allowed for real-time tracking of drug usage and inventory levels.
Phase 2: Waste reduction and recycling (2025 to 2026)
- Develop and implement a system for MDI recycling and reuse, including cleaning protocols and infection control compliance.
- Align with SCHN’s waste reduction objectives and circular economy initiatives.
Phase 3: Spacer alternatives and consumables (2026)
- Introduce paper spacers as a sustainable alternative.
- Review and optimise spacer-to-episode ratios.
- Implement bedside storage and education on appropriate spacer use.
Initial results show reduced carbon emissions
Interim results from solution 1 (in phase 1) demonstrate measurable progress across key performance indicators.
- Carbon emissions from MDI use has decreased from a baseline of 9163kg CO₂e to 7519kg. This is on track to reach the pilot’s target of 7330kg by December 2025.
- In the ED, the MDI-to-order ratio has improved from 1.68 to 1.2. The project’s goal is to achieve a ratio of 1.0 per episode of care.
- Spacer use has reached its target ratio of 1.0 per episode, down from 1.25.
- MDI medication cost per episode has reduced from $19.01 to $16.68.
Baseline preventer prescribing rate for patients admitted to the ward from ED was 5% in 2023 and 2024. A mid-winter review in 2025 has seen this rate increase to 33% with a target of 60%, with strategies to identify patients who meet risk-benefit criteria still in progress. Preventer prescribing should lead to a reduction in re-presentation rates; the project team is undertaking analysis to measure impact on current baseline ED re-presentation rates (20.4%) and length of stay (42 hours).
These findings support the feasibility and impact of targeted, system-level interventions in reducing the carbon footprint of paediatric respiratory care, while maintaining or improving clinical outcomes. The project aligns with the SCHN Strategic Plan and Net Zero Pathway, contributing to broader health system sustainability goals.
