“Vocal anaesthetic”: The key role and unique challenges of anaesthesia in IR

As interventional radiology (IR) evolves and expands, so too does the role of anaesthetic support to get these patients safely through their procedures. Where previously anaesthetic support was reserved for only the most acute and complex patients, now, some centres have regular anaesthetic lists supporting elective, urgent and emergency work.

Maintaining standards
Anaesthesiologists’ experience in the traditional ‘theatres’ means they can bring that knowledge across, setting standards for anaesthesia, such as recommended emergency airway equipment, a go-to box for anaesthetic emergencies like malignant hyperpyrexia, and stockage of appropriate medication. Having a regular anaesthetist also means these standards are regularly reviewed and revised.

It also brings across a culture of theatres, championing morning huddles or team briefs; completion of the WHO [World Health Organisation] checklist and debriefing sessions; efficient turnaround time between cases and better list utilisation overall.
The presence of anaesthetists within the IR suite permits the teaching of skills critical to safe patient management, airway management skills, for example, and the transfer of knowledge that will enhance patient satisfaction. Postoperative pain management is an example of such knowledge, the importance of which will be seen in years to come as the repertoire and complexity of IR procedures continues to grow.

Patient population
Studies have shown that the mean age of patients in IR is 3.5 years higher than those having surgery. With increasing age, you see increasing co-morbidities.

Certainly, in the surgical population there has been a significant increase in patient complexity as reflected in their American Society of Anaesthesiologists (ASA) Physical Status grade. Previously, ASA 1 patients made up 35% of the surgical population whereas now they make up just 15%. Naturally, the percentage of ASA 2, 3 and 4 patients has increased, and overall, patients have increased numbers of health conditions and poorer control of existing conditions.

Certain subsets of IR patients may demonstrate this heightened risk more clearly than others. A recent three-month audit of patients presenting on the anaesthetic list for lower limb angioplasty at a major teaching hospital in London, revealed that 23% of patients were octogenarians, 23% were ASA 4 and above, and 17% were not for resuscitation in the event of a cardiac arrest. Many of these patients present as urgent cases—best practice national guidance recommends that they should be revascularised within five days of their admission to hospital.3 Strict adherence to this practice leaves little time to optimise them prior to their procedure.

The nature of IR means that the patient considered too high-risk for a surgical procedure, or an open technique, is referred for a minimally invasive one instead. High-risk refers to the anticipated surgical insult associated with major surgery, which the team intend to mitigate through a minimally invasive technique, thus reducing physiological stress on the body. However, there remains an associated risk from anaesthesia, which is independent of the surgical or procedural approach. This anaesthetic risk may be significantly prolonged, in some cases, with procedures taking many hours to complete.

When anaesthetising patients in IR, it is important to strike the right balance between anaesthetic approach, procedural technique and patient risk factors. Often “a less is more” approach suits the high-risk patient better.

Type of work
The challenge comes when anaesthetists are unfamiliar with the nature of the procedure, particularly the approach and the duration. Additionally, the type of work in IR is often a mixture of elective, urgent and emergency work, meaning it is a hybrid of a traditional elective lists and emergency lists from theatres: a combination of stable patients having minor procedures, like sclerotherapy and unstable patients having life-saving procedures like embolization. A flexible and adaptable mindset is therefore needed when working in IR.

The challenge, and possibly the enjoyment, of anaesthetic lists in IR is that no two lists are alike. Patient demographics differ wildly from one to the next and procedures vary significantly from gastrointestinal procedures to vascular work.

Education and training
Anaesthetic training has not kept pace with the growth in demand for anaesthetic involvement in delivering care in the IR environment. Remote-site anaesthesia is given consideration within the anaesthetic curriculum, however, the concentration of IR services, mainly in larger teaching institutions, and the relative lack of specific focus on this subject in the training syllabus, means that most anaesthetic trainees have little to no exposure to IR until their final years of training, or until they become consultants.

The knowledge and experience gap that needs to be crossed, as a consultant, is therefore significant. The initial learning curve is steep and there is a lack of resources to support the education and training of anaesthetists who are interested in this field. It may take months to years for consultants to become comfortable with IR procedures and practices, and to acquire the mindset and techniques required to operate effectively within the IR environment. A wholesale change in thinking is needed to address this, from the teams who create the training curriculum, to the rota makers who assign trainees to theatre lists. Going forward, training lists in IR need to be seen as mandatory rather than just a tick-box option.

Location and space
One of the obstacles that face anaesthetists who work in IR is the unfamiliar environment. IR suites are often in a remote location in the hospital and away from the main theatre complex. The anaesthetic support that can be found in main theatres is not available in IR and the anaesthetist must work closely with their anaesthetic assistant to deliver care. In an emergency, help from a fellow anaesthetist is not close at hand. This much is also true for the IR anaesthetist who needs relief for a lunch break or to review a patient.

In addition, the configuration of IR suites has often not taken the needs of the anaesthetic team into consideration, with limited space for the anaesthetic machine, which can be far from the head end of the table. Access to an anaesthetic room is preferable but again with limited space, a luxury that the IR suite cannot always afford.

A combination of the above challenges breeds a reluctance in anaesthetists to deliver regular anaesthetic lists in IR.

Safety
The lack of regular anaesthetist-supported lists has led to many procedures being completed under local anaesthetic or “vocal anaesthetic”, when ideally, they should have anaesthetic involvement.

There is much debate over whether procedures, such as oesophageal dilatations, should be done under “vocal anaesthetic” with (or without) radiologist-delivered sedation, or under general anaesthetic. Centres all across the country use a different approach and each have their merits. The benefits of anaesthesia delivered by an anaesthetist is that the radiologist and their team can focus on the procedure, whilst the anaesthetist can focus on the patient, ensuring they are adequately analgised, anaesthetised and monitored.

This is ever more important when dealing with sick patients. Regular exposure to emergency work, and benefitting from formal training in intensive care medicine, anaesthetists are well versed in the management of medical emergencies that may be encountered both inside and outside of the operating theatre. Their leadership qualities come to the fore when dealing with the unstable or deteriorating patient.

Summary
Anaesthetists are uniquely placed to collaborate with IR teams on patient safety and maintaining the same standards of practice as theatres to ensure effective care is delivered.

Though there are many unique challenges to providing care in this setting, with increase in workload, it is certain that more and more centres will recognise the value of regular lists. Supported by the Society of Anaesthesia and Radiology, undoubtedly some of these challenges, like a lack of familiarity with the environment and procedures, will be rectified.

Overall, as a speciality, consideration needs to be given to adopting a surgical theatre approach to delivering care and at the centre of this is anaesthetic support.

Authors Nazia Khan and Pele Banugo are consultant anaesthetists at Guy’s and St Thomas’ NHS Foundation Trust, London and Sanya Patel is an anaesthetic trainee at Lewisham and Greenwich NHS Trust, London, UK.

The authors declared no relevant disclosures.