MHRA Issues National Patient Safety Alert on ResMed Astral 100/150 Ventilators (August 2026): Supercapacitor Leakage May Interrupt Ventilation Therapy

Published: 6 October 2026, 13:30 · Category: Recalls and Safety Notices

Event Overview

On 17 August 2026, the UK Medicines and Healthcare products Regulatory Agency (MHRA) issued National Patient Safety Alert NatPSA/2026/004/MHRA covering the ResMed Astral 100 and Astral 150 ventilators, together with the associated printed circuit board assembly (PCBA) spare parts. The alert was triggered by a ResMed Field Safety Notice (FSN) issued in the same period.

MHRA defines the scope boundary as follows: all of the above devices and spare parts manufactured before October 2024 fall within the scope of this alert. The specific affected models and serial numbers are to be determined by the appendix to the FSN.

Failure Mode

The failure mechanism described by the authorities is that a supercapacitor inside the device may leak electrolyte, corroding specific circuitry on the PCBA and thereby causing unexpected interruption of ventilation therapy.

If the leakage occurs during ventilation, ventilation stops immediately and a high-priority audible alarm is triggered; the user interface may display a therapy alarm and a red “Safety System Fault” screen. If it occurs in standby mode, a maximum-volume alarm is triggered, but no message may be shown on the user interface. Once the failure has occurred, the ventilator will not operate and cannot be restarted; alternative ventilation must be used immediately.

Risk and Scope

Astral ventilators are used in hospital, community and home settings to provide life-sustaining ventilatory support for adults and children, covering tracheostomy ventilation, ventilator-dependent patients and mouthpiece ventilation.

MHRA states that the incidence rate is not high: approximately 0.1% calculated over an 8-year device service life. At the same time, MHRA notes that if ventilation is interrupted and backup ventilation cannot be provided immediately, serious injury or even death may result. The alert is therefore classified as a “safety-critical and complex” national patient safety alert, requiring implementation to be coordinated by a senior responsible officer within the organisation.

Supply Constraints and Required Actions

MHRA states that replacement PCBAs are currently subject to global supply constraints, and that ResMed cannot for the time being provide a definitive completion timeline covering all affected devices. Available replacement parts are therefore being allocated in order of clinical risk priority.

The eight required actions listed in the alert must be completed by 17 February 2027, and include:

• Circulate the FSN within 2 working days to the respiratory, critical care, paediatric, community and home ventilation teams concerned;
• Identify all affected devices and spare parts in use or in stock;
• Within 1 month, confirm that ventilator-dependent patients have immediate access to a usable backup ventilator or another emergency ventilation solution;
• Verify and record training for caregivers and staff on recognising the alarm and executing the emergency procedure;
• Have clinicians complete an individual patient clinical risk assessment within 1 month and record the outcome;
• Contact the manufacturer in accordance with the FSN to arrange inspection;
• Consider switching the highest clinical risk patients to an alternative ventilator;
• Do not initiate new patients on Astral devices where a suitable alternative is available.

Do Not Discontinue Use Unilaterally

The alert specifically warns that discontinuing ventilation itself carries serious risk. Patients should not stop using affected devices without advice from their clinical team and without an available alternative ventilation solution. Where obtaining replacement or alternative ventilators is difficult, organisations should escalate through local procurement channels and the Department of Health and Social Care (DHSC) National Supply Disruption Response (NSDR) service. Suspected or actual device adverse events should be reported through the respective reporting routes for England, Scotland, Wales and Northern Ireland.

Sources and Applicability

• Medicines and Healthcare products Regulatory Agency (MHRA) — GOV.UK National Patient Safety Alert NatPSA/2026/004/MHRA, 17 August 2026: https://www.gov.uk/drug-device-alerts/national-patient-safety-alert-resmed-astral-100-and-150-ventilators-potential-for-patient-harm-due-to-unexpected-interruption-of-ventilation-therapy-natpsa-slash-2026-slash-004-slash-mhra
• Medicines and Healthcare products Regulatory Agency (MHRA) — Central Alerting System (CAS) alerts list: https://www.cas.mhra.gov.uk/SearchAlerts.aspx?displayPattern=4
• ResMed Field Safety Notice (FSN) hosted by MHRA: https://mhra-gov.filecamp.com/s/d/kNOU5UN6lkbN1BJW

Verification scope and access date: The full text of the GOV.UK alert (including the failure description, required actions, affected devices, key clinical considerations and reporting routes) and the MHRA Central Alerting System (CAS) alerts list were verified. Access date: 6 October 2026.

Applicability: This article is an interpretation of publicly available regulatory information and does not constitute a conclusion or commitment regarding any specific product, company or registration application. Affected models and serial numbers are subject to the appendix of the official FSN; required actions and timelines are subject to the MHRA text; information may change with subsequent official updates.

AIMEILI Regulatory Interpretation

Alert hierarchy: FSN versus NatPSA

This case illustrates the two-tier structure of UK field safety communication. The ResMed Field Safety Notice is the manufacturer-issued corrective action communication, while the NatPSA is a nationally mandated alert issued through the MHRA Central Alerting System. The NatPSA carries board-level accountability, a defined completion deadline and a formal set of auditable actions, which means the manufacturer’s FSN alone is not sufficient to close the matter in the UK market.

Manufacturer obligations and evidence expectations

For manufacturers, the practical compliance workload falls into four areas: timely distribution of the FSN to all affected users and competent authority channels; identification and traceability of all affected devices and spare parts, including inventory held by distributors; a corrective action plan with risk-based allocation of constrained replacement parts and documented justification for any allocation decisions; and complete records of the field action, including acknowledgment logs and effectiveness checks.

Because replacement parts are in global shortage and no full completion schedule can be given, the risk of the action extending beyond the deadline is real. Documented rationale, interim risk mitigation and proactive communication with MHRA are therefore essential to avoid the situation being escalated as a compliance failure rather than a supply-chain constraint.

Design, component and post-market considerations

The failure mode is component-level (electrolyte leakage from a supercapacitor) but is being managed as a device-level patient safety risk. This reinforces the expectation that design verification, component qualification, shelf-life and service-life testing, and risk management follow ISO 14971 principles, with clear linkage between component-level failure modes and clinical hazard analysis. Change control over the PCBA and its bill of materials, and post-market surveillance trending of service-life-related failures, are the areas most likely to be examined in a future audit or notified body review.

Cross-market implications

Manufacturers and registration holders should assess whether the same PCBA batches or component lots were placed on other markets, and determine whether equivalent field actions, vigilance reports or authority notifications are required in those jurisdictions. Decisions and their justification should be documented, because regulators increasingly compare field action scope across regions.

Business Impact

For manufacturers

• Cost and capacity: A replacement programme covering devices manufactured before October 2024, executed under supply constraints, typically becomes a multi-quarter cost and operations item.
• Regulatory exposure: Failure to demonstrate good-faith progress against the 17 February 2027 deadline may trigger escalation, further mandatory actions or restrictions on supply.
• Design and supply chain: Pressure to redesign or requalify the affected PCBA, and to strengthen incoming component controls and supplier qualification for safety-relevant components.

For distributors and service providers

• Traceability: Device and spare-part inventory must be re-checked against the FSN appendix to separate in-scope from out-of-scope units.
• Customer communication: Documented notification to hospitals and home-care providers, with acknowledgments retained as objective evidence.
• Service load: Inspection and replacement activity will compete with routine maintenance capacity, particularly where the installed base is large.

For hospitals, home-care providers and clinical teams

• Contingency ventilation: Confirming immediate access to backup ventilation for ventilator-dependent patients is the most time-critical action (one month) and the most resource-intensive.
• Training and documentation: Alarm recognition and emergency procedure training must be verifiable and recorded.
• Procurement decisions: Adding new patients to affected devices should be avoided where a suitable alternative exists, which will shape near-term purchasing and device standardisation strategies.

For regulatory affairs and CRO teams

• Deadline management: The six-month window from 17 August 2026 to 17 February 2027 requires a tracked action plan with owners, evidence and audit-ready files.
• Lifecycle linkage: If the affected component or PCBA is used in other devices or submitted in pending registrations, a change-control and registration impact assessment should be initiated.
• PMS integration: The event should be reflected in post-market surveillance reporting, vigilance files and management review, so that the field action and its resolution are traceable in the quality management system.

Key takeaway: A low reported incidence rate does not reduce the compliance weight of this alert. The critical factors for all parties are documented in-scope determination, risk-prioritised allocation of constrained parts, auditable completion of the eight required actions by 17 February 2027, and clear evidence that patients were never left without an alternative ventilation pathway.