Definitions and Distinctions

Voluntary consent

Consent must be given freely without pressure or undue influence. Pressure may come from other family members, partners or other carers and doctors must be aware of this. Competent adults may refuse a treatment in its entirety, though may not compel a doctor to perform part of a treatment if by refusing specific components of a treatment, the doctor feels the treatment as a whole now presents an increased risk to the patient. Consent may be implied by the conduct of the patient during interactions with the health care professional (holding an arm out for venepuncture). While this may prevent a claim of trespass against the health care professional, it does not demonstrate that the patient has had the material risks of the procedure explained to them and that they have understood. Where a procedure carries a material risk, informed consent must be obtained. Recent case law has also raised the importance of the timing the consent process; the patient must have an appropriate time to consider the information given to them and make a decision. Taking consent on the day of surgery may be construed as placing undue duress on a patient and may make the consent obtained open to legal challenge.


Informed consent

A patient must understand the nature, purpose and potential complications of any procedure to be considered informed. They should be aware of all the alternatives available to them including not having the procedure performed and the consequences of inaction. The amount and nature of information disclosed to the patient must be tailored to the individual and address what this patient would regard as relevant. Commonly occurring side effects should be discussed. Rare risks should be discussed where it is felt that the potential for such an event (no matter how rare) would change the patient’s decision to proceed; this is of particular importance where a complication may be of special significance to the individual (vocal cord damage to a professional singer). A recent legal decision has emphasized this stating that clinicians should take “reasonable care to ensure that the patient is aware of any material risks involved in any recommended treatment and of any reasonable alternative or variant treatment”. Furthermore, not only must the nature and material risks of the procedure be explored but the operators and their relative experience should also form part of the consent discussion. The late change of operating staff may also leave the consent process open to legal challenge.


Competence and capacity

A competent adult is a person who has reached 18 years of age (16 in Scotland) and who has the capacity to make decisions on their own behalf regarding treatment. A person demonstrates capacity if they are able to:

  1. Understand the information relating to the decision they are about to make.
  2. Retain that information.
  3. Use or weigh that information as part of the process of making that decision
  4. Communicate that decision to others.

No other person may consent to treatment on behalf of a competent adult and an apparently unreasonable decision by a patient does not necessarily imply that a patient lacks competence. A patient’s ability to comprehend and make a balanced choice may be affected by factors such as shock, fatigue, pain or medication, however their presence does not preclude the patient retaining the capacity to self-determine and in some cases patients may have capacity to consent to some interventions but not to others.


Refusal and withdrawal of consent

If a competent patient makes a voluntary and informed decision to refuse a treatment, this must be respected, except in circumstances defined by the Mental Health Act (1983), even if this results in the death of the patient or an unborn child. A competent patient is entitled to withdraw consent at any time, including during the performance of a procedure. A patient may on occasion wish to withhold consent for part of a procedure or technique (e.g. wishes general anaesthesia, but not cannulation awake or anaesthesia but not awake fibre optic intubation). Where selective refusal occurs, a practitioner is not required to offer the procedure as a whole if refusal of part of it (i.e. the awake fibre optic intubation) renders the overall technique unsafe. If a patient does object during a procedure, the treatment must be stopped immediately and the reasons for the patient’s decision established as well as the consequences of failing to complete the procedure explained. If the sudden abandonment of the procedure places the patient’s life in immediate danger, then it should be continued and stopped at the earliest point when this risk has passed.



Patients who have deliberately harmed themselves may present complex difficulties in their treatment, particularly if they are refusing assistance. Where a patient has attempted suicide and/or rendered themselves unconscious, emergency treatment should be given if there exists any doubt regarding their intentions or capacity at the time of the injury. If a patient is able to communicate, then they should have an assessment of their mental capacity and if deemed to be not competent treated on a basis of temporary incapacity. If a competent patient has deliberately harmed themselves and is refusing treatment, a psychiatric opinion should be sought. If the use of the Mental Health Act (1983) is not appropriate, then their refusal must be respected, although attempts should be made to encourage them to seek help.


Here are some useful links looking at consent:

  1. GMC – consent resources
  2. HM Government – reference guide for consent for examination or treatment
  3. Association of Anaesthetists of Great Britain and Ireland (AAGBI) – consent for anaesthesia*
  4. British Medical Association (BMA) – consent guidance
  5. AAGBI – guidance on anaesthesia for Jehovah’s Witnesses
  6. Consent in anaesthesia, critical care and pain medicine. Orr, T. et al. BJA Education, Volume 18, Issue 5, 135 - 139


Consent law is constantly evolving and the consent process is increasingly under scrutiny when complications in surgery and anaesthesia arise. Recent developments have placed a far greater emphasis on materiality (what matters to the patient) and have questioned the validity of consent when there are late changes to the surgical plan or team or whether taking consent on the day of surgery itself places the patient under duress. Here are some up to date explanations of the latest developments and controversies in consent law:

  1. Hailsham Chambers (2015) – The Montgomery decision and its effect on consent
  2. (2015) – The Jones decision and its effect on patient choice and late changes
  3. McCombe K, Bogod D. Paternalism and Consent: Has the law finally caught up with the profession? Anaesth 2015;70:1016–1019
  4. McLeod A. A summary of recent consent cases in relation to the Montgomery ruling


Here are some useful podcasts looking at case studies involving complex consent issues:

  1. Inside the Ethics Committee, BBC Radio 4 – Needlesticks and HIV testing (ITEC)
  2. Inside the Ethics Committee, BBC Radio 4 – Learning difficulties and consent





*This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. Please cite all material as: ‘Source: AAGBI: Consent for anaesthesia 2017: Association of Anaesthetists of Great Britain and Ireland. Yentis SM, Hartle AJ, Barker IR, et al. Anaesthesia 2017; 72: 93-105.

A summary of recent consent cases in relation to the Montgomery ruling


Rodney Crossman v St George’s Healthcare Trust [2016]

Mr Crossman had degenerative cervical spine disease and had neck pain and paraesthesia. A neurosurgeon advised three months physiotherapy with a follow-up clinic appointment.
However, Mr Crossman was also listed for surgery inadvertently, and received appointments for pre-operative assessment and an operation date. He attended the pre-assessment appointment as he had been informed that he could lose his place in the waiting list if he did not.

At pre-assessment he was advised of perioperative risks, and issues related to his warfarin treatment. He was asked whether he really wanted to go ahead, and he clearly stated that he did. He went forward to surgery, after which he unfortunately emerged with a nerve root injury.

Mr Crossman won damages by claiming that the original treatment plan had not been followed. The operation had not been performed negligently, but he argued that his accidental listing for surgery led to his complications. Although his consent process included discussions of these risks, the court found that his consent was pressured by having his surgery scheduled much sooner than he was expecting. The court also thought that Mr Crossman did not have a duty to question the hospital’s erroneous discussion to schedule him prematurely for surgery, i.e. he was not contributory.


Hassell v Hillingdon Hospitals [2018]

Mrs Hassell was a 41-year-old secondary school teacher, with a history of spinal disease. She had previously had decompression and fusion surgery to her lumbar spine, but had developed new problems of pain and paraesthesia in her left arm. She saw a spinal surgeon, who arranged an MRI scan. This showed a disc lesion with some spinal cord compression. She was advised to have a cervical discectomy procedure with fusion or disc replacement.  There was dispute as to what risks were explained in clinic, and the surgeon wrongly believed that Mrs Hassell had already received physiotherapy. Mrs Hassell signed her consent form on the day of surgery, which included ‘cord injury’ as a risk. She was placed earlier on the list than she had expected, and felt hurried to proceed. She unfortunately emerged from surgery with tetraparesis, and a severe lasting disability.

She was awarded damages of £4.4m, by successfully claiming that she had not been adequately warned of all the risks of surgery, and had not had time to consider alternatives. The judge decided that had she been fully warned of the risks, particularly tetraparesis, she would not have proceeded with surgery.

Her surgeon could not demonstrate that he had warned her of these complications, and his assertion that these risks would be shared as ‘usual practice’ was not accepted as evidence. Although spinal cord injury had been listed on the consent form, the fact that this had been signed on the day was also seen as allowing insufficient time to consider this adequately.


Key themes

Both these cases demonstrate how courts are applying the principles of the Montgomery judgment to disputes over consent. Failures in consent are also increasingly used as a route to recover damages for complications, rather than claiming that a procedure was negligently performed.

  • Patients must have time to consider the risks and benefits of ‘the recommended treatment, and of any reasonable alternative or variant treatments’.  i.e. patients should understand all their options (including having no treatment) very clearly.
  • Good communication with patients is critical to establish what treatment they wish, and explain what complications may occur. The dialogue in clinic is the most important part of the consent process, and this should be carefully documented in case of future disputes.
  • Doctors cannot refer to their ‘usual practice’ to support an assertion that they warned a particular patient of a given risk. Relying on the practice of other doctors as defence i.e. the Bolam principle, is not valid when judging cases of consent. The information shared will be judged according to what a reasonable person in this position would want to know and what the particular patient in question would find significant.
  • As in Jones v Exeter, (where the patient learnt very late that a different surgeon would be operating),  disclosing information for the first time on the day of surgery does not give patients sufficient time to make an informed, unpressurised decision, and consent can be seen as inadequate.
  • Changes in the treatment plan, without proper discussion may also be viewed as placing the patient under pressure to proceed.



  1. Rodney Crossman v St George’s Healthcare Trust [2016] EWHC 2878 (QB).
  2. Hassell v Hillingdon Hospitals NHS Foundation Trust [2018] EHWC 164 (QB).
  3. Montgomery v Lanarkshire Health Board [2015] UKSC 11.
  4. Jones v Royal Devon and Exeter NHS Foundation Trust (Lawtel 22 September 2015).


Dr Andy McLeod
RCoA Safeguarding Group

August 2018