A medicolegal perspective on anaesthesia

Anaesthesia is one of the largest and most wide-ranging medical specialties, and it is used in some form in around two-thirds of all hospital patients. It is generally a very safe procedure, and the risk of adverse events is low. Furthermore, many of the complications that do occur are minor and temporary in nature. However, a small proportion result in permanent harm or even death. Given the low risks, claims for medical negligence are relatively rare, although the number has risen in recent years. Between 70 and 180 of the claims reported to the NHS each year are attributable to anaesthesia, which equates to around 5% of the total number of reported claims. Although the number of claims is low, settlement favours the patient in approximately two-thirds of claims and the damages awarded can be significant.   

Certain surgical specialties are more likely to result in complications, and therefore possible claims. These include orthopaedic surgery, general surgery and obstetric and gynaecological surgery. Many of the claims for the last specialty relate to awareness and pain during caesarean procedures. Overall, the majority of adverse events are associated with general anaesthesia, with those linked to regional, or local, anaesthesia accounting for a quarter of all cases at the most. There is some evidence that the risk of complications is higher for anaesthetic procedures undertaken for emergency operations than for elective surgery, suggesting that the potential for mistakes may be increased in high-pressure situations.  

One of the most frequently reported events following anaesthesia is dental injury. This is most often the result of poor intubation technique, using excessive force or touching already fragile teeth during intubation. While dental damage may occur following the use of a conventional laryngoscope, video laryngoscopy is also a predictor of dental damage, due to the user’s focus being more on the screen than on the patient’s teeth. However, when used by skilled operators, this technique can result in a lower risk of injury to the teeth. The risk of dental damage is considerably increased when there is pre-existing dental pathology or a history of intubation difficulties in the patient. Regardless of the mechanism of damage, the teeth most likely to be affected are the upper maxillary incisors, with avulsion and enamel fractures neing the most likely occurrences.  

Nerve injuries are probably more common than has previously been reported, occurring at rates of 3 and 1.5 events per 100,000 anaesthesia procedures for neuraxial and peripheral nerve injuries respectively. They are most frequently associated with orthopaedic surgery and are predominately caused by the formation of haematomas following neuraxial nerve blocks, including epidural and spinal anaesthesia. Nerve damage is rarely caused by regional anaesthesia. While both sensory and motor function deficits can be experienced, only a very small minority of patients report paraesthesia. In some cases, permanent damage may occur.   

A small number of medical negligence claims arise due to the inadvertent administration of a neuromuscular blocking drug to an awake patient. This can be caused by a previously unflushed peripheral cannula, particularly where the use of a short multi-lumen extension set attached to the cannula has enabled the retention of residual drugs in quantities sufficient to affect the patient. The resulting paralysis, however brief, can have a higher rate of significant distress than awareness during general anaesthesia.  

Although airway management claims are rare, they include instances of “cannot ventilate, cannot intubate” and are often associated with high severity in terms of patient outcome. Permanent neurological, respiratory and psychological injuries have all been reported. Therefore, the costs associated with successful claims can be very high. Issues related to patient monitoring include inappropriate interpretation of monitors and a failure to promptly identify and respond to adverse events including low blood pressure, resulting in neurological injury or cardiac arrest.   

Communication failures can also be problematic. Lack of consent is cited in many claims for medical negligence and appears to be particularly associated with events with serious outcomes. In particular, patients complain of a lack of explanation of alternative treatment options to the one given, even though current guidelines emphasise that adequate consent should include a discussion of alternative forms of anaesthesia and pain relief. Many claims relate to central or peripheral nerve blockade which has resulted in permanent neurological injury or block failure. Omission of warnings about the potential for permanent injury or the possibility of nerve blockade failure not only constitutes a breach in the expected standard of care but one that is entirely avoidable.  

Anaesthetic complications are infrequent and rarely lead to litigation. As the majority of claims are settled in favour of the patient, when claims do arise, they can be costly. Furthermore, anaesthetists may be involved in complaints that have arisen due to surgical procedures, particularly post-operative complications. Many claims could be avoided by improved training and education, adherence to guidelines, and the maintenance of high clinical standards. The ability to work well with other people is also essential, as there is increasing evidence that in anaesthesia teamwork has more influence on successful patient management than individual skill.