Intensive care medicine

Regional anaesthesia

Anesthesia

Medicine

Anaesthesia

“Any intelligent fool can make things bigger and more complex…….it takes a touch of genius and a lot of courage to move in the opposite direction.” —Albert Einstein Einstein is, of course, referring to a subconscious behavioural pattern that is currently afflicting many aspects of modern medicine: complexity bias. This is the belief that something is better if it is more complicated. The advent of ultrasound-guided regional anaesthesia has heralded a rapid growth in the number of nerve block techniques, with a particular zeal for interfascial plane blocks. Many of these approaches differ by the tiniest of margins or a thin fascial layer and are often accompanied by a suitably clever acronym. Many enthusiasts strive to perform the newest and most complex nerve blocks with the hope of delivering the highest quality care to their patients. However, in doing so, these clinicians may be placing disproportionally high value onto new, unproven, under-researched and undervalidated techniques. This enthusiasm-based practice can supersede evidence accrual, fuelled by an explosion of case reports and rushed low-quality studies. Authors are keen to be the first to publish novel applications of these techniques and journals know these articles will attract citations. What we must consider though, is how this recent expansion in nerve block approaches is impacting the day-to-day delivery of regional anaesthesia on a larger scale. Let us take the example of an elderly patient with rib fractures. In the not-so-recent past, options for analgesia included an epidural or a paravertebral block. Today, the general anaesthetist can choose between erector spinae plane (ESP), intercostal, midpoint transverse process, retrolaminar, rhomboid-intercostal subserratus or serratus plane blocks, to name but a few 1. In a busy clinical setting, how does one differentiate the exact anatomical location, needling approach or sonographic end-point between each technique, especially when comparative evidence is lacking? Paradoxically, this trend to create more ultrasound-guided nerve blocks risks widening the gulf between the regional anaesthesia cognoscenti and generalists. Only a small number of anaesthetists may actually understand and regularly perform these novel blocks, whereas the remainder may see regional anaesthesia as becoming too complex and intimidating. Many will choose the path of least resistance and avoid using regional anaesthesia at all. Patient access to regional anaesthesia is generally low around the world, and a change in approach may be required to facilitate a more widespread availability to our patients 2. In addition, there is growing awareness of the benefits of regional anaesthesia in the facilitation of day surgery, as reflected in recent guidelines stating that all anaesthetists should be familiar with peripheral nerve blocks 3. Based on these facts, there is a disproportionate emphasis within the academic regional anaesthesia community on creating novel blocks which rely on an intricate understanding of anatomical minutiae that very few practising anaesthetists will perform. Naturally, every researcher wants to create the nerve block that changes modern medicine, but there is possibly more to be gained by investigating how we can pragmatically and practically improve the availability and consistent delivery of regional anaesthesia to all patients. We must, therefore, ask ourselves some difficult questions: do we really need any more blocks? Should we first learn how to get the best out of what we have? We believe that a desirable change in clinical practice will occur as the result of inclusion rather than exclusion. As a regional anaesthesia community, we must evaluate how we can engage and integrate the majority of anaesthetists into practising regional anaesthesia on a regular basis. Regional anaesthesia must shift from the perception of novelty, to its acceptance as a core component of peri-operative care. But how can we increase access and equity in the provision of regional anaesthesia to the wider population? How do we cement basic regional anaesthesia skills as a core competency for all anaesthetists, similar to that of airway management, monitoring of fluid status or the newly recommended core competency of total intravenous anaesthesia 4? To this end, we suggest three key components to making positive changes towards extending the provision of regional anaesthesia to the greatest number of patients (Fig. 1). Peri-operative pain management starts with multi-modal analgesia, of which regional anaesthesia is a key component. Promotion of widespread competence in performing a small number of nerve blocks which cover the vast majority of surgical procedures can allow greater patient access to regional anaesthesia. For most patients having any given surgery, regional analgesia can commonly be achieved with one technique appropriate for that surgery (Plan A). On rare occasions, the anaesthetist may need a backup regional anaesthesia option (Plan B). The general anaesthetist may want to focus on mastering a few Plan A blocks for various surgical procedures, which, if unsuccessful would leave the patient with a modern general anaesthetic and multimodal analgesic strategy. The specialist in regional anaesthesia should be expected to have a solid regional anaesthesia Plan B with even a Plan C and D depending on the patient and situation. The exact constituents of this ‘basic blocks package’ require further investigation to select blocks that improve outcomes, enhance efficiency, increase access and decrease disparity 5. It is important to note that the overall aim of this package of blocks is to provide the highest possible value to the greatest number of patients; therefore, in some cases a compromise must be reached between impact on patient outcomes and the potential for non-experts to successfully perform the block on a regular basis. We highlight an example of an initial package of nerve block techniques that are worth considering (Table 1), although there remains much to debate, revise and reconsider in this package. This group of basic nerve blocks is not aimed at the experienced regional anaesthetist; it's goal is to provide the regional anaesthesia novice with a small number of basic techniques that can provide analgesia for the majority of surgical procedures and improve overall value of care. Practical regional anaesthesia skills are also transferable; therefore, competence in these basic blocks will facilitate anaesthetists’ adoption of additional techniques as needed. Of note, we recommend that standardised ultrasound-guided approaches should be established for all basic block techniques. Achieving widespread competency in a set of basic nerve blocks for common indications is an important step towards improving patient access to regional anaesthesia. This step will require a shift in both the minimum regional anaesthesia competencies required for completion of training in anaesthesia and the availability and quality of simulation tools to enable more experienced anaesthetists to develop and maintain their skills. Aiming to raise the bar of competence in basic nerve block procedures is not an overnight task and must start with addressing current shortfalls in training curricula. In the United States, a graduate of an accredited anaesthesia residency program is required to have provided care for 40 patients who have received peripheral nerve blocks 6. There is no specific breakdown of what these nerve blocks should be or how much repetition is required. With the current menu of regional anaesthesia techniques, a resident may realistically achieve this minimum criterion by having one experience each with 40 different nerve blocks. In the UK, the Royal College of Anaesthetists higher training curriculum classifies regional anaesthesia as a non-essential element of a broad unit of training known as ‘general duties.’ Within this broad training unit, anaesthetic trainees are required to complete nine of the 14 general duties subspecialties, of which only three are compulsory: airway management; peri-operative medicine; and management; of respiratory and cardiac arrest 7. It is, therefore, entirely conceivable that a trainee could either not complete any regional anaesthesia assessments in their higher training modules before completion of training, or could complete their ‘general duties’ regional anaesthesia training unit by performing the documented minimum competencies of one observed upper limb block, one observed lower limb block and a thoracic epidural. The feasibility of ensuring competence in regional anaesthesia may also be hampered somewhat by a research environment focusing primarily on novel techniques, rather than exploring better or more accessible ways to teach and maintain competence in regional anaesthesia. Practical skills in regional anaesthesia can be broken down into two predominant components: sono-anatomical knowledge; and needle-transducer manipulation. The former can be learned using a variety of textbooks or multimedia platforms to assist the development of pattern recognition before patient contact, and the latter can be perfected using realistic regional anaesthesia simulation models 8. Learning these skills before patient contact avoids rushed negative pre-operative learning experiences with surgeons circling overhead. In an ideal world, the majority of regional anaesthesia prerequisite education should take place outside of the operating theatre. One of the major hurdles in achieving this goal is that current nerve block simulation techniques are lacking in their realism, effectiveness and availability 9. This will undoubtedly improve with ongoing technological advancements, but at present, the most realistic form of regional anaesthesia simulation remains the use of cadaveric specimens, which are not readily available to all, and are associated with expensive one-off educational courses in contrast to repeated needling exposure over a longer period of time. Maintaining these competencies remains a challenge. However, for the majority of anaesthetists, the most clinically-relevant and practical method for achieving this requires regular performance of a smaller number of techniques (Table 1). Once knowledge barriers of individual anaesthetists are achieved, we must then overcome the final hurdles of practically implementing these blocks into clinical pathways and addressing the systematic and cultural barriers to regional anaesthesia in daily practice (Table 2) 10. Many of these barriers may be overcome by improving research and awareness into the benefits of regional anaesthesia towards patient experience and overall value of care, along with improving widespread access to effective methods of attaining and maintaining regional anaesthesia skills. We must also find a way of pragmatically and objectively quantifying the overall value of each technique, such as that recently described by Mudumbai et al. 5. There are many important factors which may contribute to the perceived value of a particular regional anaesthesia technique including quality, cost, ease of integration and ease of access, and these factors may differ based on the anaesthesia practice and institutional environment. Quality parameters may include patient experience, early postoperative patient-reported outcome measures and long-term outcomes such as persistent post-surgical pain. Cost parameters may include length of hospital stay, theatre efficiency, day of surgery cancellations, duration of recovery stay and postoperative hospital re-admissions. Ease of integration considers practical components such as procedural positioning and duration, whereas ease of access refers to consideration of the technical skill to perform the block and whether this is generalisable. To put this in context, a quadratus lumborum block would score lower for efficiency and ease of access compared with a transversus abdominis plane (TAP) block, but may score higher on outcomes 11. A paravertebral block would score higher for analgesic outcomes compared with the ESP block but less for increasing access 12. A combined technique of femoral and sciatic nerve blocks for total knee arthroplasty may score higher for analgesic outcomes but would score less favourably than the adductor canal block for early mobilisation, efficiency and increasing access 13. Hence, it is entirely conceivable that for specific groups of surgical procedures, a subset of nerve blocks could be objectively scored according to their contribution to the overall value of the peri-operative pathway in question. This could assist the busy clinician in sifting through the vast array of heterogenous evidence for different regional anaesthesia approaches and could provide a focus for researchers, with regular updates when new evidence becomes available. That being said, there is currently a lack of research focus exploring the impact of regional anaesthesia integration into peri-operative pathways on patient experience, patient-reported outcome measures and overall value of care. Moving this field forward will require solid science: high-quality, adequately powered studies that compare the effectiveness of novel blocks to established standards in terms of meaningful clinical and patient-centred outcomes. In summary, although there is, and always will be, a need to develop and understand novel regional anaesthesia techniques, a more pragmatic approach to the delivery of regional anaesthesia might be more beneficial to our patients. Research and training in regional anaesthesia require a deliberate strategy to identify a small number of versatile ‘high value’ nerve blocks, attaining and maintaining widespread competency in these skills and promoting their implementation into peri-operative pathways. Regional anaesthesia is not quantum physics, nor should it be. By moving away from the concept of the ‘many blocks for the few’ to ‘a few blocks for the many’, regional anaesthesia can grow from a niche subspecialty to a core component of anaesthetic care available to all. KE is an Editor of Anaesthesia. EM's contribution to this work is supported with resources and the use of facilities at the VA Palo Alto Health Care System (Palo Alto, CA, USA). The contents do not represent the views of VA or the United States Government. No other competing interests declared.

Future directions in regional anaesthesia: not just for the cognoscenti