Risk and the duty to inform

The recent Inner House judgment in the case of NM v Lanarkshire Health Board [2013] CSIH 3 (23 January 2013) deals with the complex area of informed consent and explores the extent to which a doctor is obliged to advise a patient of the risks involved in undergoing a medical procedure.

The pursuer and reclaimer, NM, was admitted to her local maternity hospital on 30 September 1999, at 38 weeks plus four days, for induction of labour. NM was an insulin-dependent diabetic. Women who suffer from diabetes are likely to have larger than average babies. They are also at an increased risk of mechanical problems giving birth either due to cephalopelvic disproportion (CPD) or foetal abnormalities and stillbirth in the later stages of pregnancy. CPD may be absolute (where the baby’s head cannot be delivered) or relative (where the baby’s head is delivered but the shoulders become stuck above the pelvis, known as shoulder dystocia). The pursuer’s pregnancy was defined as high risk and would require intensive monitoring.

NM was induced on the evening of 30 September. By 1700 on 1 October, NM was transferred to theatre for an attempt at forceps delivery. At 1745, the baby’s head was delivered but as a result of shoulder dystocia, the rest of the baby’s body became stuck. It took a further 12 minutes for the baby’s body to be delivered. During those 12 minutes, the baby was deprived of oxygen and required resuscitation upon delivery. The baby boy was subsequently diagnosed with cerebral palsy and a brachial plexus injury involving Erb’s palsy.

NM’s case at proof was that the consultant obstetrician, Dr McL had been negligent in (1) the management of labour, by failing to interpret the CTG traces as meriting earlier intervention; and (2) obtaining informed consent, by failing to advise the pursuer of the risks of vaginal delivery (including shoulder dystocia) and offering the alternative of caesarean section. Quantum was agreed at £5.25m inclusive of interest. Following proof, the Lord Ordinary concluded that NM had failed to prove negligence on the part of Dr McL and assoilzied the defenders. NM reclaimed.

The appeal focused on the mismanagement of labour, and consent issues. Insofar as mismanagement of labour is concerned (which is outwith the scope of this article), the Inner House upheld the Lord Ordinary’s finding that Dr McL was not negligent in continuing with the labour and failing to intervene earlier than she did.

Two branches of consent

The argument in relation to the consent issue was twofold: (1) Dr McL had a duty to unilaterally give advice to a diabetic mother about the risks of shoulder dystocia; and (2) when asked specifically about a particular risk, Dr McL had a duty to answer truthfully.

It is of relevance to the consent issue that NM had undergone several ultrasound scans during her pregnancy and at the 36-week scan, the estimated foetal weight was on the 95th centile. The baby’s predicted birth weight was 3.9kg. NM had expressed concerns about her ability to deliver a big baby naturally. No ultrasound scan was carried out at the 38th week of pregnancy, as Dr McL felt it would be detrimental to NM’s psychological health to have this done.

The evidence at proof was that where diabetic women give birth to a baby estimated as weighing 4kg or more, there is a 9-10% risk of shoulder dystocia occurring. However, where shoulder dystocia does occur, most cases are dealt with by the midwives/doctors involved without the patient becoming aware it has happened. The risk of severe injury resulting from shoulder dystocia is very small (1/500 for a brachial plexus injury, and of that 1/500 only 1-2% would be diagnosed with cerebral palsy).

(1) Duty to unilaterally advise of risks

NM’s counsel sought to rely on Pearce v United Bristol Healthcare NHS Trust [1999] ECC 167 in submitting that the law was beginning to move towards a more patient-focused approach. He argued that in assessing whether a doctor should advise of a significant risk, the judgment of the reasonable patient should be taken into account. In the present case, therefore, a diabetic pregnant woman should be advised of the 9-10% risk of shoulder dystocia notwithstanding the risk of a grave outcome was small.

The Inner House rejected this argument. They adopted the approach laid down in Sidaway v Board of Governors of the Bethlem Royal Hospital [1985] 1 AC 871, namely that it is a matter of clinical judgment for a medical practitioner to decide whether to warn a patient of risks. The same test of liability should be applied as in other aspects of medical practice (Bolam/Hunter v Hanley). Sidaway recognised that the court is entitled to find in certain circumstances that “disclosure of a particular risk was so obviously necessary to an informed choice on the part of the patient that no reasonably prudent medical man would fail to make it”, but this would only be in circumstances where there was “a substantial risk of grave, adverse consequences”. The Inner House agreed with this approach in determining that as a matter of professional responsibility, Dr McL was not required to spell out to NM the very small risk of a grave outcome.

(2) Specific enquiry as to risk

In Sidaway, Lord Bridge opined that “when questioned specifically by a patient of apparently sound mind about risks involved in a particular treatment proposed, the doctor’s duty must… be to answer both truthfully and as fully as the questioner requires”.

NM’s evidence at proof was that she had specifically asked Dr McL about the risks of a vaginal delivery. The Lord Ordinary did not find NM’s evidence credible and reliable on this point which meant it was not open to challenge on appeal. However, before the Inner House, NM’s counsel submitted that when NM expressed concern at the 36 weeks ante-natal clinic about her ability to deliver a big baby vaginally, this consituted a specific enquiry and, as such, should have prompted a discussion about risks.

The Lord Ordinary, having heard the evidence of both NM and Dr McL, concluded that NM’s concerns were of a general nature only and did not give rise to a duty on Dr McL’s part to give a detailed explanation of the risks involved in a vaginal delivery. Dr McL was entitled to reassure NM that vaginal delivery would be attempted and if difficulties arose a caesarean section could be considered.

The Inner House agreed with the Lord Ordinary, stating: “It is one thing to say that specific questioning will call for a full and truthful answer… But the same cannot in our view be said of general anxieties and concerns which, of themselves, set no obvious parameters for a required response. In such a case there may be no plausible stopping-point short of a legal duty to explain all possible risks to all patients who express general anxieties or concerns… Too much in the way of information or warnings may only serve to confuse or alarm the patient, and it is therefore very much a question for the experienced practitioner to decide, in accordance with normal and proper practice, where the line should be drawn in a given case.”

Causation

In the event that negligence had been proven, NM would still have required to prove causation. The issue of causation can be considered by asking the question – but for the doctor’s negligence, what would the outcome, on the balance of probabilities have been? The question in NM’s case was – had she been made aware of the risk of shoulder dystocia, would she have chosen a caesarean section and avoided damage to the child? NM’s evidence was that she would have elected to have a caesarean section. The Lord Ordinary did not accept her evidence on this point (he felt she would still have attempted vaginal delivery looking at the evidence as a whole), and so the case failed on causation.

NM’s counsel submitted at proof and on appeal that the House of Lords decision in Chester v Afshar [2005] 1 AC 134 should be relied upon in providing the necessary causal link. His submission was that the response which the patient would have given to the advice about risks, had she received that advice, was not to be treated as determinative. He argued it was sufficent in proving causation that a risk of grave consequences, of which risk there was ex hypothesi a duty to advise, had in fact materialised.

In Chester, the House of Lords modified the normal principles of causation to provide the claimant with a remedy. The neurosurgeon in that case failed to advise the claimant who underwent spinal surgery of the small risk of cauda equina syndrome which she went on to develop post-surgery. The House of Lords held that the claimant had proven causation despite the fact she could not say whether, if she had been advised of the risk, she would not have proceeded with the surgery. They acknowledged that this was a departure from traditional causation principles, but justified this on the basis that “The function of the law is to enable rights to be vindicated and to provide remedies when duties have been breached” (per Lord Hope).

In NM’s case, the Inner House agreed with the Lord Ordinary’s findings on causation. They rejected the argument that Chester should apply, stating their opinion that the House of Lords did not intend that the modification of causation principles should apply to all cases where there has been a failure to advise of risks. They sought to differentiate NM’s case on the basis that whereas in Chester the patient’s reaction could not be established in evidence, there was a positive finding that NM would not have elected to have a caesarean section had she known of the risk of shoulder dystocia.

Comment

In discussing the risks of a medical procedure, there will undoubtedly be a balancing act for doctors. In NM’s case, this could be the difference between reassuring and scaring a first time mother. However, where the risk of shoulder dystocia (given her particular circumstances) was as high as 10%, was NM not entitled to a full discussion about that risk, especially when she had expressed concern about her ability to deliver a big baby? Her concern was not simply about the process of labour but more specifically about the delivery of a big baby. Is it unfair to expect a patient with a non-medical background to know exactly how to word the question which would have triggered a discussion about risks?

The case highlights the difficulties facing a pursuer who attempts to argue an informed consent case. The doctor will, more often than not, be entitled to defend his/her position by arguing that in deciding which risks they chose to discuss with a patient, he/she had the patient’s best interests in mind. If this case is taken as an example of the approach the court will take, there will be a reluctance to interfere with the treating doctor’s decision in determining which risks should and should not be discussed.

The Inner House declined to follow the House of Lords’ approach in Chester v Afshar where the principles of causation were modified to allow the claimant a remedy. Chester v Afshar has not advanced the position on consent as many hoped it would, and is treated very much as a case on its own facts.