When an anaesthetic goes wrong: can a patient in NSW make a medical negligence claim for anaesthesia errors?
You went in for a procedure. You trusted the team. You expected to wake up and recover. What happened instead was something you did not anticipate, were not adequately warned about, or were never properly explained after the fact. The procedure may have been routine. The anaesthetic was not.
That gap — between what you expected and what occurred — is not simply a matter of bad luck. Anaesthesia is one of the most tightly regulated clinical disciplines in Australian medicine. The standards are specific. The monitoring requirements are detailed. The consent obligations are demanding. When a complication arises, the question is not whether something went wrong. The question is whether the clinical team met the standard the law required of them.
If that question is familiar, this article is written for you. It sets out what the standard of care requires of anaesthetists in Australia, where that standard is most commonly breached, and what the law in NSW says about when an anaesthesia complication becomes a compensable act of negligence.
What anaesthesia is and how it should be managed
Anaesthesia is the medically induced state of controlled unconsciousness, sedation, or regional nerve blockade that allows surgical and procedural interventions to occur without pain or distress. Three broad types are used in Australian clinical practice: general anaesthesia (full unconsciousness), regional anaesthesia (nerve block or spinal/epidural), and sedation (a spectrum from light to deep, without full unconsciousness).1
According to the Healthdirect Australia patient information framework, anaesthesia is administered by specialist anaesthetists — medical practitioners who have completed specialist training through the Australian and New Zealand College of Anaesthetists (ANZCA). In Australia, anaesthesia-related mortality is low by international standards, but serious complications — including awareness under anaesthesia, cardiovascular collapse, hypoxic brain injury, and anaphylaxis — do occur and are not always unavoidable.2
Standard anaesthetic management involves four distinct phases: pre-operative assessment, induction, maintenance, and emergence (recovery). Each phase carries specific clinical obligations. The anaesthetist must assess the patient’s fitness for anaesthesia, select appropriate agents and doses, secure and maintain the airway, monitor vital signs continuously, and manage any adverse events in real time. A failure at any of these stages can cause harm that ranges from temporary distress to permanent neurological injury or death.
What it requires: Continuous monitoring of oxygenation, ventilation, circulation, and temperature during every anaesthetic. The standard mandates pulse oximetry, capnography (end-tidal CO₂ monitoring), ECG, and non-invasive blood pressure measurement as minimum requirements for all general anaesthetics.
Why this matters: Failure to apply or respond to these monitors — or their absence from the record — is a direct indicator of a potential breach of the standard of care.
The standard of care — what anaesthetists are required to do
In law, the “standard of care” means the level of skill and care that a reasonably competent practitioner in the same specialty would exercise in the same circumstances. For anaesthetists, that standard is set not by what is customary in a particular hospital, but by what ANZCA’s professional standards and the broader body of specialist anaesthetic practice require.3
The standard is demanding because the stakes are high. An anaesthetist assumes complete control of a patient’s airway, consciousness, and cardiovascular stability. The patient cannot advocate for themselves during that period. The law recognises this asymmetry and holds the anaesthetist to a correspondingly rigorous standard of vigilance.
What a competent anaesthetist is required to do, at each phase, includes the following. Before the procedure: conduct a thorough pre-operative assessment, review the patient’s medical history, allergies, and medications, identify risk factors for difficult airway or adverse drug reactions, and obtain properly informed consent for the anaesthetic — separately from the surgical consent. During induction: select appropriate agents and doses calibrated to the patient’s weight, age, and comorbidities, confirm airway patency before proceeding, and have a documented plan for a difficult airway. During maintenance: monitor all required parameters continuously, respond to any deterioration in real time, and communicate with the surgical team. During emergence: ensure the patient is adequately reversed from neuromuscular blockade before extubation, monitor for post-operative nausea, pain, and respiratory depression, and hand over to recovery staff with a complete clinical summary.
What it requires: Every patient must receive a pre-anaesthesia consultation with the administering anaesthetist before the procedure. This consultation must cover the patient’s medical history, planned anaesthetic technique, material risks, and alternatives — and must be documented.
Why this matters: An anaesthetic administered without a documented pre-operative consultation, or where the patient’s known risk factors were not assessed, represents a failure at the most foundational stage of safe anaesthetic practice.
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PRE-OPPre-operative Assessment
The anaesthetist reviews history, allergies, medications, and airway anatomy. Risk factors for difficult intubation, anaphylaxis, or cardiovascular instability must be identified and documented. Informed consent for the anaesthetic is obtained separately from surgical consent.Failure here: No pre-op assessment documented; known allergy not flagged; patient not warned of material risks. -
INDUCInduction
Anaesthetic agents are administered. Airway is secured (mask, laryngeal mask airway, or endotracheal tube). Correct placement is confirmed by capnography. Dose is calibrated to patient weight, age, and comorbidities.Failure here: Oesophageal intubation not detected; overdose in elderly patient; anaphylaxis not recognised and treated immediately. -
MAINTMaintenance
Continuous monitoring of oxygenation (SpO₂), ventilation (EtCO₂), blood pressure, and ECG. Anaesthetic depth is titrated. Any deterioration triggers immediate clinical response. The anaesthetist remains present and attentive throughout.Failure here: Hypoxia not detected; anaesthetic awareness due to inadequate depth; haemodynamic collapse not managed. -
EMERGEmergence and Recovery
Neuromuscular blockade is reversed before extubation. The patient is monitored for respiratory depression, laryngospasm, and post-operative nausea. A complete handover is given to recovery nursing staff.Failure here: Premature extubation; inadequate reversal of paralysis; respiratory arrest in recovery not detected promptly.
Based on ANZCA professional standards PS07, PS18, and PS54. Each stage carries specific, documented obligations.
Where anaesthetic care breaks down — specific failure patterns
Anaesthesia errors do not follow a single pattern. They occur across the four phases of care, involve different clinical actors, and produce different types of harm. The following failure patterns represent the most clinically significant and legally relevant categories.
Airway mismanagement
Securing and maintaining the airway is the anaesthetist’s most fundamental obligation. Failure to do so — whether through failed intubation, unrecognised oesophageal intubation, or delayed response to laryngospasm — can produce hypoxic brain injury within minutes.
The ANZCA Difficult Airway Guidelines require every anaesthetist to have a documented plan for managing a difficult or failed airway before induction begins.4 When a patient has anatomical features that predict difficulty — a short neck, limited mouth opening, or a history of previous difficult intubation — the standard requires heightened preparation, including the availability of video laryngoscopy and a surgical airway backup plan.
She told the anaesthetist before the procedure that a previous surgeon had noted her airway was difficult. Nobody documented it. Nobody prepared for it. When the tube went into the oesophagus instead of the trachea, three minutes passed before anyone recognised the error. By then, her oxygen saturation had dropped to a level that caused permanent neurological damage.
The mechanism behind this failure is not incompetence in isolation. Confirmation bias plays a significant role: once an anaesthetist believes the tube is correctly placed, they interpret ambiguous monitoring signals as consistent with that belief rather than questioning it. Capnography — the gold-standard confirmation tool — eliminates this ambiguity. Its absence from the record, or a documented failure to respond to a flat capnography trace, is a clear indicator of breach.
Drug and dose errors
Anaesthetic agents are potent, narrow-margin drugs. The difference between a therapeutic dose and a toxic dose is often small, and the consequences of error are immediate. Drug errors in anaesthesia include administering the wrong agent, the wrong dose, the wrong route, or failing to account for a documented allergy.
The Australian Commission on Safety and Quality in Health Care has identified medication errors as a leading category of preventable harm in Australian hospitals, with anaesthesia-related drug errors representing a significant subset.5 Syringe swap — where two drugs in similar syringes are administered in reverse — is a recognised and preventable error. ANZCA’s professional standards require colour-coded labelling and standardised syringe preparation protocols specifically to prevent this failure.
He was given a neuromuscular blocking agent without adequate anaesthetic depth. He was paralysed and unable to move or communicate, but conscious. He experienced the entire procedure. Nobody in the theatre noticed, because the monitoring did not include a processed EEG (brain activity monitor) — a tool that, while not universally mandated, is increasingly considered standard practice for high-risk patients.
Anaesthetic awareness
Anaesthetic awareness — the experience of regaining consciousness during a procedure while remaining paralysed — is one of the most psychologically devastating complications of general anaesthesia. Australian data suggests it occurs in approximately 1–2 per 1,000 general anaesthetics, though underreporting is likely.6
Awareness is not always negligent. In some emergency situations, the anaesthetist must accept a lighter plane of anaesthesia to preserve cardiovascular stability. But awareness that results from inadequate monitoring, failure to titrate anaesthetic depth, or failure to respond to clinical signs of lightening — such as tachycardia, hypertension, or patient movement — does not fall within acceptable clinical risk. It falls within breach.
Failure to obtain informed consent for anaesthesia
Anaesthetic consent is legally distinct from surgical consent. A patient who consents to a surgical procedure has not thereby consented to the anaesthetic. The anaesthetist holds an independent duty to disclose the material risks of the proposed anaesthetic technique — including the risk of awareness, nerve damage from regional blocks, dental injury, aspiration, and anaphylaxis — and to discuss alternatives.7
In Rogers v Whitaker (1992) 175 CLR 479, the High Court of Australia established that the test for disclosure of risk is not what clinicians customarily disclose, but what a reasonable patient in the plaintiff’s position would want to know.8 A patient who has a known anxiety disorder, a history of awareness, or who has specifically asked about the risks of being awake during surgery has a heightened claim to disclosure. Failure to provide it is a failure of consent — and a potential breach of duty.
What happened: A patient suffered a serious complication following a procedure and argued that she had not been adequately warned of the relevant risk before consenting.
What the court found: The Court of Appeal confirmed that the duty to warn extends to risks that a reasonable patient in the plaintiff’s particular circumstances would consider significant — applying the Rogers v Whitaker standard and rejecting the proposition that professional custom alone determines the scope of disclosure.
Why this matters: Anaesthetists cannot rely on what they routinely tell patients. The disclosure obligation is calibrated to what this patient, in their specific circumstances, needed to know.
Monitoring failures
ANZCA’s PS18 standard is unambiguous: continuous monitoring of oxygenation, ventilation, circulation, and temperature is mandatory for every general anaesthetic. A patient who suffers hypoxic injury during a procedure where pulse oximetry was not applied, or where a deteriorating oxygen saturation was not acted upon, has experienced a failure that sits squarely within breach of the standard of care.
Monitoring failures often arise from systemic pressures — a busy theatre list, equipment that was not checked before the case began, or a handover between anaesthetists mid-procedure without adequate briefing. The structural cause does not reduce the legal consequence. The standard applies regardless of the pressures under which the clinician was working.
The legal framework in NSW
Medical negligence claims in New South Wales are governed primarily by the Civil Liability Act 2002 (NSW). This legislation sets out the framework for establishing breach, causation, and the defences available to clinicians and health services.
Section 5O of the Act provides a defence where a clinician acted in a manner that was widely accepted by peer professional opinion as competent professional practice. This is the “peer professional opinion” defence — sometimes called the Bolam-equivalent in Australian law, though it operates differently. Critically, section 5O(2) provides that the court is not bound to find that a risk was not foreseeable, or that a standard was met, simply because a body of professional opinion supports the defendant’s conduct. The court retains the power to find that the peer opinion was irrational or contrary to established guidelines.9
Section 5D addresses causation. To establish that a breach caused harm, a plaintiff must show that the harm would not have occurred “but for” the defendant’s negligence. In anaesthesia cases, this often requires expert evidence about what would have happened had the correct monitoring been applied, the correct drug been administered, or the correct airway management plan been followed.
The duty of care in anaesthesia is owed by the anaesthetist personally, and may also be owed by the hospital or day surgery facility as the employer or as the entity responsible for the systems and equipment within which the anaesthetist worked. Both may be defendants in a negligence claim.
What happened: A patient suffered serious harm following a medical procedure, and the question of causation — specifically, what would have happened had the clinician acted differently — was central to the claim.
What the court found: The High Court confirmed that causation in medical negligence requires the plaintiff to establish, on the balance of probabilities, that the breach materially contributed to the harm — and that this assessment must be grounded in the clinical evidence of what proper care would have produced.
Why this matters: In anaesthesia cases, causation is often the most contested element — expert evidence about what timely intervention would have prevented is essential to establishing the claim.
For a comprehensive overview of how medical negligence claims operate in NSW, see Reframe Legal — Medical Negligence.
When an anaesthesia complication may amount to negligence
When the pre-operative assessment was inadequate or absent
If the anaesthetist did not conduct a documented pre-operative consultation, failed to review the patient’s allergy history, or did not assess the airway before induction, the foundational obligation of safe anaesthetic practice was not met. This failure engages the duty of care directly. Where that failure then contributed to a complication — an unrecognised allergy causing anaphylaxis, a difficult airway not anticipated — causation is established by the direct link between the omission and the harm.
When a known risk was not disclosed
If the patient had a specific risk factor — a history of awareness, a known difficult airway, a documented allergy — and the anaesthetist did not disclose the heightened risk or discuss an alternative technique, the consent was not lawfully obtained. Under Rogers v Whitaker, the failure to disclose a material risk that the patient would have wanted to know is a breach of the duty of care. If the patient would have declined the procedure, or chosen a different anaesthetic technique, had they been properly informed, causation is established.
When monitoring was absent or ignored
If the anaesthetic record does not document continuous monitoring of the required parameters, or if the record shows a deteriorating value that was not acted upon, the breach is documented in the clinical notes themselves. Hypoxic injury following a period of unmonitored or unaddressed oxygen desaturation is one of the clearest examples of a preventable harm that the standard of care was designed to prevent.
When a drug error caused direct harm
Administering the wrong drug, the wrong dose, or a drug to which the patient had a documented allergy — and where that error caused measurable harm — engages all three elements of negligence simultaneously. The duty is clear. The breach is the error itself. Causation follows directly from the pharmacological consequence of the wrong agent or dose.
The three elements of negligence applied to anaesthesia errors
Every medical negligence claim — regardless of the clinical context — must establish three things: that the clinician owed the patient a duty of care, that the clinician breached that duty, and that the breach caused the harm the patient suffered. In anaesthesia cases, the duty is rarely in dispute. The contest is almost always about breach and causation — and both require expert clinical evidence to resolve.
Anaphylaxis to a drug with no prior documented allergy, where the anaesthetist responded promptly and correctly — this is a known risk of anaesthesia that falls within acceptable clinical uncertainty.
Hypoxic brain injury following a period where pulse oximetry was not applied, or where a falling oxygen saturation was documented but not acted upon for several minutes — a preventable harm caused by a failure to meet the monitoring standard.
This is a general educational framework only. Each case depends on its individual facts and circumstances.
Long-term and permanent harm from anaesthesia errors
The physical consequences of anaesthesia errors range widely depending on the nature and duration of the failure. Hypoxic brain injury — caused by a period of inadequate oxygen delivery to the brain — can produce permanent cognitive impairment, memory loss, motor deficits, and in severe cases, a persistent vegetative state. Nerve damage from regional anaesthesia errors, including epidural haematoma or direct nerve injury, can cause chronic pain, weakness, or paralysis in the affected limb or region.
Anaesthetic awareness produces psychological harm that is frequently severe and long-lasting. Post-traumatic stress disorder following awareness under anaesthesia is well-documented in the clinical literature.10 Patients describe the experience as one of the most terrifying of their lives — paralysed, unable to communicate, aware of pain or surgical manipulation, and unable to signal distress. The psychological sequelae can persist for years and may require sustained psychiatric treatment.
| Error Category | What Should Have Happened | What Went Wrong | Harm Produced |
|---|---|---|---|
| Airway Mismanagement | Airway assessed pre-op; difficult airway plan documented; capnography used to confirm tube placement | Oesophageal intubation not detected; no difficult airway plan; capnography absent or ignored | Hypoxic brain injury; cardiac arrest; death |
| Drug / Dose Error | Allergy history reviewed; colour-coded syringe labelling; dose calculated for patient weight and age | Wrong drug administered (syringe swap); overdose in elderly patient; known allergen given | Anaphylaxis; cardiovascular collapse; prolonged paralysis; awareness |
| Monitoring Failure | Continuous SpO₂, EtCO₂, ECG, and BP monitoring applied and documented throughout | Monitors not applied; deteriorating values not acted upon; anaesthetist absent from theatre | Undetected hypoxia; cardiac arrhythmia; hypotensive organ injury |
| Consent Failure | Separate anaesthetic consent obtained; material risks disclosed; alternatives discussed | No pre-op consultation; risks not disclosed; patient’s specific risk factors not addressed | Patient denied opportunity to decline or choose alternative; psychological harm; legal invalidity of consent |
Based on ANZCA professional standards and Australian Commission on Safety and Quality in Health Care incident data.
Financial consequences compound the physical and psychological harm. Lost income during recovery, the cost of ongoing rehabilitation, neurological or psychiatric treatment, and in cases of permanent disability, the lifetime cost of care and support — all of these form part of the compensable loss in a successful negligence claim.
What compensation covers in NSW
Compensation in a medical negligence claim in NSW covers two broad categories. General damages compensate for pain, suffering, and loss of amenity — the non-economic impact of the harm. Under section 16 of the Civil Liability Act 2002 (NSW), general damages are only available where the severity of the non-economic loss is at least 15% of the most extreme case. This threshold is relevant to moderate injuries; it does not affect claims for serious or catastrophic harm, which will almost always exceed it.11
Special damages compensate for quantifiable financial losses. These include past and future medical and hospital expenses, rehabilitation costs, past and future lost income, the cost of domestic assistance and care, and aids and equipment required as a result of the injury.
| Severity of harm | Indicative range (NSW) | Key factors |
|---|---|---|
| Moderate injury with recovery | $50,000–$150,000 | Duration of pain, treatment required, time off work |
| Serious injury with lasting effects | $150,000–$500,000 | Permanent impairment, ongoing treatment, care needs |
| Severe or life-changing injury | $500,000–$2,000,000+ | Catastrophic loss of function, lifetime care, lost earnings |
These figures are general reference ranges only. Each case turns on its own evidence — medical records, expert clinical opinion, and economic reports that quantify the actual loss.
The limitation period for medical negligence claims in NSW is three years from the date the person knew, or ought reasonably to have known, that they had a claim — under the Limitation Act 1969 (NSW). For anaesthesia injuries where the harm was not immediately apparent, or where the patient was not told what occurred during the procedure, the discovery rule may extend the period from which time runs. This is a technical question that requires legal analysis of the specific facts.
How to think about your own situation
The question at the beginning of this article — whether anyone explained what went wrong — sits at the centre of what many people in this situation are trying to resolve. The absence of an explanation is not evidence that nothing went wrong. It is often evidence of the opposite.
When several of these questions align with what happened, the pattern they describe is one that legal analysis — grounded in the anaesthetic record, the monitoring chart, and expert clinical opinion — can assess objectively. The anaesthetic record is the most important document in any claim of this kind. It either confirms that the standard was met, or it reveals the gap. For a detailed explanation of how this process works, see Reframe Legal — How Medical Negligence Claims Work in NSW.
Uncertainty is normal — and it is not evidence that nothing went wrong
Most people who have experienced an anaesthesia complication carry significant uncertainty about what happened and why. That uncertainty is rational. The operating theatre is a closed environment. The patient was unconscious. The clinical team controls the record. What the patient knows is what they were told — and in many cases, what they were told was incomplete, delayed, or framed in a way that minimised the clinical failure.
Legal analysis does not depend on the patient’s certainty. It depends on objective evidence: the anaesthetic chart, the pre-operative assessment notes, the consent documentation, the recovery room record, and the expert opinion of an independent anaesthetist who can assess whether the standard was met. The patient’s job is not to prove what happened. The patient’s job is to provide the factual account of their experience. The legal and clinical analysis does the rest.
The standard of care is an objective test. It asks what a reasonably competent anaesthetist would have done in the same circumstances — not what this particular anaesthetist intended, believed, or felt under pressure to do. Good intentions do not satisfy the standard. Compliance with ANZCA guidelines does. Where the record shows a departure from those guidelines, and where that departure caused measurable harm, the legal framework provides a pathway to accountability.
For further information on the consent obligations that apply to anaesthesia specifically, see Reframe Legal — Informed Consent and Medical Negligence. For information about the regulatory framework that governs anaesthetists in Australia, including the complaints process, see AHPRA — Australian Health Practitioner Regulation Agency.
About the author
Dr Rosemary Listing holds a PhD in medical negligence and practises as a specialist medical negligence lawyer in New South Wales. She also holds medical qualifications, and her practice sits at the intersection of clinical medicine and legal accountability — giving her the analytical tools to examine both what the standard of care required and where the clinical record shows it was not met.
Anaesthesia errors represent one of the most legally and clinically complex categories of medical negligence. The standard is set by detailed ANZCA professional guidelines, the harm can be catastrophic and permanent, and the evidence — the anaesthetic chart, the monitoring record, the consent documentation — is technical and requires expert interpretation. The legal analysis demands fluency in both the clinical and legal dimensions of the failure.
The pattern that emerges from cases reaching NSW courts and HCCC complaints in this area is consistent: the anaesthetic record either documents the standard being met, or it reveals the gap. Monitoring values that were not acted upon, pre-operative assessments that were not conducted, consent conversations that were not documented — these failures appear in the clinical notes themselves. The record is rarely neutral.
People who seek legal examination of their anaesthetic records are rarely looking to blame anyone. They are looking for an honest answer to a question that the clinical team did not give them: was what happened to me avoidable? Many have waited months or years before seeking that answer, carrying uncertainty about whether their experience was a known risk or a preventable failure.
Dr Listing examines anaesthetic records alongside independent expert clinical opinion to give an honest, evidence-based answer to that question — and where the standard was not met, to pursue the legal accountability that the law in NSW provides.
- Australian and New Zealand College of Anaesthetists (ANZCA), Types of Anaesthesia, ANZCA Patient Information, Melbourne, 2023.
- Healthdirect Australia, Anaesthesia, Australian Government, 2023, available at healthdirect.gov.au.
- Australian and New Zealand College of Anaesthetists (ANZCA), PS55 Recommendations on Minimum Facilities for Safe Administration of Anaesthesia in Operating Suites and Other Anaesthetising Locations, ANZCA, Melbourne, 2012 (reviewed 2022).
- Australian and New Zealand College of Anaesthetists (ANZCA), PS54 Statement on the Relationship Between Fellows and the Health Services Where They Work, and Difficult Airway Society / ANZCA joint guidelines on management of the unanticipated difficult intubation, 2016.
- Australian Commission on Safety and Quality in Health Care, Medication Safety, ACSQHC, Sydney, 2023, available at safetyandquality.gov.au.
- Errando CL et al, “Awareness with recall during general anaesthesia: a prospective observational evaluation of 4001 patients”, British Journal of Anaesthesia, 2008, 101(2):178–185; see also Mashour GA et al, New England Journal of Medicine, 2019, 380:2635–2644 for contemporary incidence data.
- Australian and New Zealand College of Anaesthetists (ANZCA), PS26 Guidelines on Consent for Anaesthesia or Sedation, ANZCA, Melbourne, 2005 (reviewed 2023).
- Rogers v Whitaker (1992) 175 CLR 479 (High Court of Australia).
- Civil Liability Act 2002 (NSW), ss 5O, 5D.
- Lennmarken C and Sydsjo G, “Psychological consequences of awareness and their treatment”, Best Practice & Research Clinical Anaesthesiology, 2007, 21(3):357–367.
- Civil Liability Act 2002 (NSW), s 16; Limitation Act 1969 (NSW), s 50C (discovery rule for personal injury).
- Dobler v Halverson [2007] NSWCA 335 (NSW Court of Appeal).
- Naxakis v Western General Hospital (1999) 197 CLR 269 (High Court of Australia).
This article contains general legal information only. It does not constitute legal advice, and reading it does not create a lawyer–client relationship. The law discussed applies to New South Wales, Australia. Each person’s circumstances differs. Time limits apply to legal claims in NSW, and these limits may affect your position. You should seek independent legal advice about your specific situation.