In Moffatt v North Metropolitan Health Service [2026] WADC 6, the District Court of Western Australia considered complex issues concerning psychiatric injury arising from a medication administration error during pre-term labour treatment.
The decision canvasses a number of different issues, some which have not been considered in detail by a WA court, including:
The plaintiff was admitted to King Edward Memorial Hospital in February 2017 following concerns she may enter premature labour at less than 30 weeks' gestation. As part of accepted obstetric management, a magnesium sulphate infusion was commenced to provide neuroprotection to the foetus in the event of early delivery.
Under the applicable hospital protocol, the medication was to be administered in two stages:
Instead, the maintenance dose was administered at the same accelerated rate as the loading dose, resulting in nearly the entire 100ml magnesium sulphate infusion being delivered within approximately 38 minutes.
The plaintiff alleged that during the infusion she experienced severe physical symptoms and escalating distress, compounded by concerns for the safety of her unborn child and the response of hospital staff. She subsequently developed psychiatric conditions including PTSD and depressive symptoms.
The defendant admitted the administration error but disputed liability, causation and quantum. It argued the plaintiff remained within therapeutic magnesium levels, that many symptoms could occur even with correctly administered magnesium sulphate, and that psychiatric injury was not reasonably foreseeable in a person of normal fortitude.
A central issue was whether the defendant owed a duty to take reasonable care not to cause psychiatric injury.
The Court undertook a detailed analysis of Part 1B of the Civil Liability Act 2002 (WA), including the distinction between "pure mental harm" and "consequential mental harm". Sefton DCJ considered whether the plaintiff had suffered a "personal injury" through impairment of either her physical or mental condition and whether psychiatric injury to a person of normal fortitude was reasonably foreseeable in the circumstances.
Importantly, the Court found the relevant risk was not confined to physical symptoms from the infusion itself. The foreseeable risk extended to the plaintiff's experience of:
The Court accepted that, in the context of a vulnerable patient in threatened pre-term labour, psychiatric injury was reasonably foreseeable.
The judgment contains substantial analysis concerning the statutory meaning of "personal injury" and "mental harm".
The Court examined whether the plaintiff initially suffered impairment of her physical condition through the symptoms experienced during the infusion, and whether that brought the claim within the framework for consequential mental harm rather than pure mental harm.
The decision carefully navigates interstate authorities and statutory interpretation principles in determining the scope of compensable injury under the Civil Liability. The reasoning may be significant in future psychiatric injury claims in WA where physical symptoms are transient or overlap with emotional distress.
A key factual dispute concerned whether the accelerated infusion rate caused symptoms the plaintiff would not otherwise have experienced had the medication been administered correctly.
The defendant contended the plaintiff remained within therapeutic magnesium levels and that many of the symptoms described were commonly associated with properly administered magnesium sulphate infusions. Therefore it could not be said that the symptoms the plaintiff experienced which she says caused her psychiatric injury were symptoms that arose because of the medication administration error.
The Court undertook a detailed review of expert obstetric and pharmacological evidence, including evidence concerning magnesium toxicity, therapeutic levels and the physiological effects of rapid infusion.
The Court accepted evidence that the plaintiff did not start to experience distressing physical symptoms until after the maintenance dose had commenced, and concluded that because the plaintiff had not experienced those symptoms during the loading dose, they were more likely than not caused by the incorrect administration of the maintenance dose.
While not all alleged symptoms were accepted, the Court found the administration error materially contributed to the plaintiff's distressing physical experience and psychological reaction. While the defendant was not successful on this occasion, the judgment nevertheless demonstrates the importance of carefully addressing and distinguishing between symptoms inherent in treatment itself and symptoms attributable to negligent administration.
For the purpose of analysing breach of duty, the Court therefore framed the relevant risks of harm as:
The Court had to consider whether failure to comply with the hospital's magnesium sulphate protocol constituted a breach of duty, accepting that non-compliance with a policy or procedure or guidance note does not, in and of itself, immediately lead to a finding of breach. The protocol was treated as important evidence of appropriate practice, rather than determinative of breach in itself. In other cases, courts have been careful to indicate that protocols might be aspirational, rather than reasonably practicable, and each case must be evaluated based on the circumstances at the time of the alleged breach.
The protocol required administration through a controlled infusion device with specific infusion rates and ongoing observations. The Court accepted that the infusion was not administered in accordance with the protocol and that monitoring requirements were not adequately followed.
Ultimately the Court found that the conduct, i.e. not complying with the protocol, fell below the standard of reasonable care in the circumstances and breach was established.
An important feature of the plaintiff's case was the allegation that staff failed to provide adequate reassurance following identification of the medication administration error.
The plaintiff alleged she was left frightened that her baby may have suffered harm and that staff did not appropriately respond to her escalating concerns.
Although the Court did not accept all of the plaintiff's allegations about lack of reassurance and explanation, the Court nevertheless found that an absence of timely reassurance and explanation formed part of the breach of duty.
This aspect of the judgment highlights the potential legal significance of communication and patient management following adverse clinical incidents, particularly in high-stress maternity settings.
If, for example, the hospital's failure to follow the protocol was not found to have been a breach, it is nevertheless possible the hospital may have been found liable for causing psychiatric harm because of the way it managed the administration error after the fact.
The judgment contains a detailed comparison of psychiatric opinions from two prominent Western Australian psychiatrists, Dr Piirto and Dr Edwards-Smith.
The experts differed on both diagnosis and causation. The Court carefully examined:
Sefton DCJ undertook a detailed credibility and causation analysis, ultimately preferring aspects of each psychiatrist's evidence rather than wholly accepting either opinion, although Dr Piirto's evidence was preferred more often than Dr Edwards-Smith's evidence because Dr Piirto had the benefit of reviewing the plaintiff on more occasions, over a broader period of time and had greater access to the plaintiff's clinical records.
The decision illustrates the forensic importance of nuanced psychiatric evidence in medical negligence claims involving complex personal histories and multiple potential stressors.
Many aspects of the claim for damages were either agreed or were minor. The largest components were for loss of earning capacity and non-pecuniary loss.
The Court had to find whether the plaintiff's psychiatric injury, as opposed to her personal circumstances and pre-existing stressors, caused any loss of earning capacity.
The plaintiff alleged that but for her psychiatric injury, she would have returned to work within six months of the birth of her child. The defendant argued that the plaintiff would not have done so because it did not make financial sense for her to return to work within that timeframe – noting the plaintiff had four children under school age who would have required paid care, among other personal circumstances which would have made it unlikely that she would enter the workforce that quickly.
Although the plaintiff experienced significant psychiatric symptoms and impairment in daily functioning, the Court agreed with the defendant's submissions and found that the impact on earning capacity was comparatively modest.
The judgment demonstrates the distinction between substantial psychiatric injury and substantial economic loss. While the plaintiff's symptoms were genuine and significant, the evidence did not establish a major reduction in long-term earning capacity attributable solely to the defendant's negligence.
Moffatt is likely to become a significant Western Australian authority on psychiatric injury in medical negligence litigation.
The decision provides extensive consideration of:
The judgment also serves as an important reminder that patient communication, reassurance and clinical response following an adverse event may themselves become central issues in negligence proceedings.
For further advice on this topic, please contact Erica Thuijs at Jackson McDonald.