This is an equipment safety alert for neonatal clinicians using the Fabian Neonatal Ventilators (Fabian HFO, Fabian HFOi, Fabian+nCPAP) for conventional ventilation in the Volume Guarantee (VG) mode.
Several UK neonatal centres have reported the ventilator to intermittently exceed the maximum Peak Inspiratory Pressure (PIP) limit (P max) set by the clinicians in the VG mode. The Pmax is set by clinicians as an upper limit of PIP to ensure a stable delivery of desired tidal volume in the face of variable lung compliance. However, it is also designed to act as a safety net to prevent inadvertent high PIP and barotrauma during technical failure of the ventilator or as a trigger for clinicians to review an infant with deteriorating lung compliance. Although the set tidal volume limit in VG mode offers some degree of protection from prolonged volutrauma irrespective of the PIP, there remains the possibility of intermittent delivery of high tidal volume when the Pmax is exceeded (the set tidal volume in VG mode is not a true volume limit but acts a guide to adjust PIP in subsequent breaths to deliver a tidal volume as close to the set target as possible). Another centre has reported significant instability of the tidal volumes and delivered PIP in VG mode associated with clinical deterioration in ELBW babies.
The problem is particularly seen in infants with either one or combination of:
a) severe lung disease and low lung compliance
b) high leak around the endotracheal tube
c) unsettled/fighting the ventilator
This issue has been reported to the manufacturer and to MHRA and an urgent solution is being sought to resolve the problem. The issue is not machine specific and has been reported on most ventilators of these models when operating on the VG mode. Although investigations are ongoing, it has been reported following software upgrade to v5.1.0 in 2020.
We would request clinicians using VG mode on the Fabian ventilator to be vigilant of this issue and undertake risk assessment to control/ mitigate the risk until a resolution is achieved. This may include:
1. Use of a different ventilator for VG mode, if available
2. Risk assess if the risk of discontinuing the VG mode and consequent swing of tidal volume outweighs the risk of intermittent overshooting of the tidal volume.
3. If using the VG mode, set alarm limits not exceeding the Pmax to ensure clinicians are aware and alerted to the issue
4. Use measures to reduce leak around the ETT and consider appropriate sedation for unsettled infants
5. For infants with severe lung disease where this issue is persistent, alternative forms of ventilation such as HFOV may be considered
As far as we are aware serious incidents of immediate harm to neonates has not been reported. Please report similar incident or any other patent safety concerns through the online yellow card reporting scheme to MHRA (https://www.gov.uk/report-problem-medicine-medical-device). When reporting such incidents, it is advisable where possible, to take a screenshot or a short video of the ventilator screen along with the serial number of the ventilator and download a log for full investigation by the manufacturers.
Consensus statement of Neonatal Clinicians
Royal Sussex County Hospital, Brighton
Singleton Hospital, Swansea Bay University Health Board
East Kent Hospitals University Foundation NHS Trust
3rd September 2020