Regional anaesthesia – the preferred choice?
Point-of-care ultrasound plays an important role in regional anaesthesia at the Queen Elizabeth Hospital in Kings Lynn, explains James Stimpson
NICE guidelines recommend the use of ultrasound guidance for regional anaesthesia and vascular access procedures. At Queen Elizabeth, we have been using ultrasound for regional anaesthetic procedures since 2004, when we purchased a SonoSite MicroMaxx® point-of-care ultrasound system. Since then, as the use of ultrasound has increased and the technology has continued to advance, we have added further systems, including two S-Nerves™ and an X–Porte®, which are chiefly used for regional anaesthesia – we perform around 2,000 peripheral nerve blocks and a similar number of neuraxial spinal procedures each year – and vascular access.
As a consultant anaesthetist with a specific interest in regional anaesthesia, I use point-of-care ultrasound systems on a regular basis as a primary anaesthetic technique for regional anaesthesia and, in some cases, for analgesia. For upper limb problems, we typically use ultrasound guidance for interscalene single-shot blocks, interscalene catheters, supraclavicular blocks, supraclavicular catheters and axillary nerve blocks, as well as for shorter-acting axillary nerve blocks in conjunction with longer-acting forearm and antecubital fossa blocks. We also do a significant number of femoral nerve blocks, lateral femoral cutaneous nerve blocks – usually for hip fracture surgery or as part of a combined strategy for knee replacements – adductor canal blocks, mid-thigh popliteal fossa blocks, popliteal fossa catheters, and multi-injection ankle blocks. Ultrasound is such a powerful tool, and the newer instruments in particular are so powerful at visualising needles. I encourage the use of in-plane imaging to obtain full needle visualisation during regional anaesthetic procedures, ensuring we get the best possible view of the needle. For me, the key thing is to visualise the needle tip and the target structure throughout the procedure, without any doubt as to where the needle tip is; the latest generation of ultrasound instruments offer a quality of image generation and rate of turnover that is ideal for this purpose.
In this part of the country, we have an elderly retirement population and, while the principle concern for most patients is effective analgesia, there is significant and increasing evidence that, as age increases, the long-standing effect of general anaesthesia is a reduction in cerebral function, or cognitive decline. Large-scale studies in the USA – particularly on primary hip surgery and knee arthroplasty – have suggested that avoidance of general anaesthesia is associated with a significant reduction in all-cause morbidity or mortality, and cardiovascular morbidity post-operatively. The use of regional anaesthesia for shoulder surgery, in conjunction with sedation if required, has also been shown to help avoid the multiple significant cerebral desaturation events that occur under general anaesthetic in the beach chair position.
For elderly patients, we use a range of regional anaesthesia strategies: for example, for knee replacements, including full-strength motor and sensory blocks, femoral and sciatic nerve blocks. For other patients – particularly those who are younger and more motivated – a hybridised technique of infiltration and adductor canal block is often used, minimising motor block to enable early mobilisation. This allows same-day or minimal length of stay surgery while still maintaining good quality analgesia, helping to avoid the need to administer opiate-based drugs. For shoulder surgery, where the aim is to provide anaesthesia rather than analgesia, full-strength interscalene blocks tend to be used or, if surgery is performed under general anaesthetic, the suprascapular nerves can be targeted, providing an isolated sensory or part-joint block for analgesia. This is particularly good for arthroscopic shoulder surgery.
The beauty of the X-Porte is its simplicity, particularly for the younger generation of anaesthetists that has grown up with smartphone technology. Its appearance instils confidence, it boots up quickly and the touchscreen interface is very intuitive to use; simple plug-and-play operation means that you can literally turn it on, pick up the probe and instantly have the correct settings to generate a functional image. The quality of the image produced is just fantastic, and the resolution is brilliant, giving much clearer differentiation of nerve tissue from other structures. Changing between probes is straightforward as the system holds multiple probes, and it is easy to clean, which is very important. The in-built training mode is also useful, particularly in theatre, enabling trainees to develop their understanding of the anaesthetic procedures involved as part of a formal educational process. Another useful feature is the capability to save anonymised images directly onto a USB stick, which trainees can then review at a later date. This is especially helpful for our anaesthesia fellows, allowing them to record procedures, demonstrating their competence and progress throughout the year-long placement.
Regional anaesthesia continues to advance, taking advantage of developments in ultrasound technology to identify the smaller peripheral nerves within tissue planes, often at multiple locations, to achieve the required outcome: optimal pain relief with minimal motor block, allowing early mobilisation. The X-Porte, with its high-frequency HFL50 probe, has revolutionised our ability to pick out small cutaneous nerves, allowing us to identify all the anatomical variants and adopt a targeted approach to performing a block, rather than the traditional approach where all the nerves in a particular area are blocked. This enables more selective regional anaesthesia, locating and blocking individual nerves – for example, the intercostal brachial or cutaneous nerves in the arm, and the posterior cutaneous, sural and saphenous nerves in the leg – so that anaesthesia/analgesia can then be provided without total motor block, allowing patients to mobilise far sooner than would otherwise be possible.
Today, the Department of Health is encouraging the movement of as much surgery as possible into a day-case setting, and one way of enabling this is by providing guaranteed pain relief for the duration you anticipate surgery to be significantly painful, as well as the anticipated time frame when patients may require, for example, parenteral opiate pain relief. In that respect, regional anaesthesia is definitely beneficial, allowing inpatient, and often other surgery associated with a two- or three-night stay, to be transferred into a day-case setting. More and more major surgery is being performed in this way, including Oxford unicompartmental knee replacements, major foot and ankle surgery, major open shoulder surgery – in fact, major open upper limb surgery of all kinds – and other procedures such as posterior approach TAP blocks, paravertebral blocks in conjunction with general anaesthesia, and moderate to major gynaecological surgery. It also enables more guaranteed post-operative outcomes, for example for laparoscopic cholecystectomy, where the expectation is increasingly for day-case surgery. Patients frequently prefer regional anaesthesia too, with or without sedation, as it allows them to return home sooner. Given the choice, most people would rather recover in the comfort of their own home than in hospital. It’s good to be able to provide that option.
James Stimpson is a consultant anaesthetist at the Queen Elizabeth Hospital King’s Lynn NHS Foundation Trust, which serves around 300,000 people across west and north Norfolk, and surrounding areas. It was one of the first trusts in the UK to set up an ambulatory regional anaesthesia service for major shoulder surgery in a day-case setting.