Beginning of the End of Blind Epidural Analgesia

Thoracic epidural analgesia has always been considered the gold standard for optimal analgesia for major thoracic and abdominal surgeries. It has also been identified as an essential component of multimodal analgesia, as recommended by the enhanced recovery after surgery guidelines.[1] However, the insertion of thoracic epidural catheters, especially at mid-thoracic levels, is challenging using an anatomical landmark-based technique due to the steep caudal angulation of the spinous processes, which is associated with high failure rates (35% of overall failure and 13% of technical failure).[1] Apart from failure, literature also elucidates the risk of complications (overall 3.1%) such as dural puncture, post-operative radiculopathy and grave complications such as epidural haematoma, abscess and needle misadvancement to the spinal cord, blood vessels and pleural cavity associated with multiple attempts.[1,2] The number of procedures required (60–90 placements to reach the technical plateau) to master this skill, along with the risk of potentially harmful complications, imparts unique challenges in the training of novice anaesthesiologists.[3] With the use of ultrasound in regional anaesthesia, more and more fascial plane blocks are now known to the anaesthesiologist. These techniques are much simpler, performed under direct vision and are not associated with serious complications. The skill for performing fascial plane blocks can be mastered rapidly, with a 90% success rate achieved within 16 procedures.[4] Pain relief provided by catheters placed in fascial planes, when combined with other components of multimodal analgesia, is equivalent to epidural analgesia.[5] The increased use of fascial plane blocks as an alternative to epidural analgesia has raised the serious question of whether it is the beginning of the end of blind epidural analgesia. Most of the current limitations and complications of epidural analgesia are linked to the procedure, which is essentially done blind and imaging modalities such as ultrasound and fluoroscopy can improve the success and outcomes of epidurals.[1] Ultrasound to aid epidural insertion has been used either in real-time or as a pre-procedural scan.[6] It has been proven to be superior to the manual palpatory method for identifying the desired intervertebral level, especially in obese or pregnant patients in the lumbar region, where the traditional palpatory method can be challenging or impossible.[7] In the first randomised control trial (RCT) done to evaluate the efficacy of ultrasound-guided epidurals in the mid-thoracic region, real-time scanning was found to be superior to traditional technique with respect to first-pass success.[8] The use of ultrasound has been recommended in obese patients for neuraxial labour analgesia by NICE guidelines 2008.[9] However, such recommendations are not yet available for mid-thoracic epidural insertion. Ultrasound-guided procedures in daily clinical practice require thorough anatomical knowledge and practical skills for visualising the intended structures. This often requires a high degree of training to develop coordinated probe needle movements, a key factor determining success.[10] The probability of successful regional blocks is higher when performed by anaesthetists experienced in regional anaesthesia due to the development of skills through practice.[10] Multiple training workshops, phantom models and simulations have been introduced to provide an enhanced background in ultrasonography and regional anaesthesia. A study done by Niazi et al. found superior performance by residents trained in skill laboratories for spine ultrasound.[11] Although simulation is found to shorten the learning curve, cost and utility can be limited in developing countries like ours. Rather, adopting the routine use of ultrasound for epidural placement and introducing it to the postgraduate curriculum will not only enhance safety and performance but also be beneficial for real-time learning.[12] However, the introduction of ultrasound-guided epidural insertion into the postgraduate curriculum presents several challenges. Perfecting the technique will require extensive training, encompassing both theoretical knowledge and practical skill development, under the guidance of trained and competent instructors, which will be a time-consuming process. Differences in anatomy and placement methods may interfere with the learning process. Provision and maintenance of ultrasound (USG) machines and teaching material are also essential and can be resource-and time-consuming at times. Formulation of standardised study material and teaching tools can introduce uniform practices and ease the training of current and future anaesthetists.[12] To conclude, it is the beginning of the end of ‘blind’ epidural placement due to its limitations, the risk involved and the availability of alternative analgesic techniques. Sincere efforts will need to be made by all teaching institutions to incorporate guided techniques for epidural placement, making the entire procedure safer and more effective. The routine use of ultrasound and incorporating its training into the postgraduate curriculum are significant steps towards this goal. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.