Application Of Echogenic Needles In High-BMI Patient Nerve Block Anesthesia

https://www.nature.com/articles/s41598-024-72620-8

1. Clinical Pain Points

High-BMI obese patients have always been a difficult group for peripheral nerve block anesthesia. A large amount of subcutaneous adipose tissue increases the depth of nerve distribution, and fat tissue has strong ultrasonic attenuation, resulting in blurred ultrasound imaging of target nerves and difficult identification of needle tips. Ordinary puncture needles have weak echo signals in high-fat tissues, serious imaging attenuation, unable to track deep puncture trajectory in real time. Clinicians can only rely on empirical blind puncture, with extremely low positioning accuracy, high incomplete block rate and frequent intraoperative pain reactions. In addition, obese patients have complex overlapping of deep blood vessels and nerves, blind puncture is easy to cause vascular injury, hematoma and nerve damage complications. Excessive local anesthetic dosage caused by inaccurate positioning also increases the risk of drug poisoning in obese patients, bringing great safety risks to clinical anesthesia.

2. Working Principle of Echogenic Nerve Block Needles

Echogenic nerve block needles solve the anesthesia difficulties of high-BMI patients through enhanced echo technology and anti-interference dual positioning system. The optimized laser deep echo marking and multi-layer electropolishing process greatly improve the ultrasonic reflection intensity of the needle body, effectively resist the ultrasonic attenuation interference of thick adipose tissues, and can present clear and stable high-brightness imaging in deep high-fat tissues, realizing full real-time monitoring of deep puncture trajectory. The high-sensitivity electrical nerve stimulation system has strong anti-fat interference ability, which can accurately capture the bioelectrical signals of deep target nerves, induce stable muscle contraction feedback, and verify the needle tip position independent of ultrasound imaging quality. The complementary dual-mode positioning technology of vision and electrical signals completely solves the problems of difficult imaging and inaccurate positioning of nerves in high-BMI patients, realizing precise deep nerve block.

3. Equipment Classification and Adaptive Scenarios

For high-BMI patient anesthesia scenarios, echogenic needles are divided into deep enhanced echo type (16G-18G) and long anti-attenuation type (19G-20G). The 16G-18G deep enhanced echo needles are suitable for patients with BMI>30, used for ultra-deep nerve block such as hip, pelvic and deep lower limb nerves, with super strong echo anti-attenuation ability, stable imaging in thick fat layers. The 19G-20G long anti-attenuation echogenic needles are suitable for patients with BMI 25-30, adapting to routine deep nerve block of upper and lower limbs, with balanced puncture stability and echo penetration. All products adopt lengthened needle body design and high-strength stainless steel material, which can meet the deep puncture needs of high-BMI patients without needle body bending and deformation.

4. Standard Operational Guidelines

Preoperatively evaluate the patient's BMI index, fat thickness and target nerve depth, select enhanced anti-attenuation echogenic needle specifications. Adopt low-frequency deep tissue ultrasound probe to scan, appropriately adjust ultrasound gain and depth parameters to enhance deep nerve imaging clarity. Mark the general running direction of deep target nerves and surrounding important vascular structures. Adopt stable in-plane deep puncture technique, advance the lengthened echogenic needle slowly and uniformly, and monitor the needle entry trajectory in real time through enhanced ultrasound images. Turn on the high-sensitivity nerve stimulation mode, fine-tune the needle position according to muscle contraction feedback until the optimal nerve proximity state is achieved. Inject local anesthetic in batches and quantitatively under real-time monitoring, observe the drug diffusion in deep tissues, confirm accurate nerve wrapping, and complete the block operation.

5. Practical Clinical Experience

Clinical data shows that echogenic enhanced needles have completely reversed the anesthesia dilemma of high-BMI patients. For obese patients with BMI greater than 30, the deep nerve block success rate of ordinary needles is only 62%, while the application of enhanced echogenic needles increases the success rate to 95%. The anti-attenuation echo structure effectively solves the problem of invisible needle tip in fat layers, reduces puncture adjustment times by more than 70%, and shortens anesthesia positioning time by half. The dual anti-interference positioning technology avoids vascular and nerve injury caused by blind puncture, and the incidence of intraoperative incomplete block and postoperative complications is reduced by 68%. Accurate positioning reduces the blind increase of anesthetic dosage, effectively reduces the risk of drug poisoning in obese patients, and makes the intraoperative anesthesia state more stable and safer.

6. Summary and sublimation

High-BMI obese patients have always been the key and difficult group of regional anesthesia due to the interference of adipose tissue on ultrasound imaging and nerve positioning. Traditional puncture tools and single ultrasound guidance technology are difficult to adapt to the deep tissue anesthesia needs of obese patients, with low accuracy and high safety risks. Echogenic nerve block needles rely on enhanced echo anti-attenuation technology and dual-mode anti-interference positioning system to break through the technical barriers of obese patient anesthesia. It significantly improves the success rate and safety of nerve block in high-BMI patients, fills the technical gap of difficult anesthesia for special groups, and improves the coverage and precision of clinical regional anesthesia.

7. Future Application Prospects and Suggestions

With the increasing prevalence of obesity, the number of high-BMI surgical patients continues to increase, and the demand for difficult anesthesia technology is rising. It is suggested to take the anesthesia of special obese groups as the key promotion direction of echogenic needle technology, and popularize enhanced anti-attenuation products in major tertiary hospitals. Formulate special anesthesia operation specifications for high-BMI patients, strengthen clinicians' operational proficiency in deep puncture and anti-interference positioning. Continuously optimize product deep echo enhancement technology, develop ultra-deep anti-attenuation special needles for severe obese patients, further improve the positioning accuracy of ultra-deep nerves, and fully guarantee the anesthesia safety of special groups.