Femoral Nerve Block Technique
By: Akhtiar Ahmed Solangi
Thele femoral nerve block is a widely used and relatively simple nerve block technique with a high success rate and low risk of complications. It has applications in both single-injection and continuous techniques.
The single-injection technique is suitable for surgeries on the front of the thigh and superficial leg surgeries below the knee. These surgeries include quadriceps tendon repair, vein stripping, and postoperative pain control after femur and knee surgeries, tibia, ankle joint, and foot surgery. For example, surgeries like interlocking nail for the femur, tension bend wire in the knee joint, interlocking nail for the tibia, broad tibia cannulated screw, ankle joint cannulated screw, menular screw, K-wire for below the knee amputation, and above knee amputation are all possible using this technique.
The continuous technique is primarily used for pain management after major femur or knee surgery and reduces the need for morphine postoperatively.
The equipment required includes sterile towels, a syringe with local anesthetic, sterile gloves, a marking pen, and a small needle for skin infiltration.
The patient is positioned supine with the leg slightly abducted and externally rotated. The needle is inserted just below the femoral crease and to the side of the femoral artery pulse. This block affects the quadriceps muscle, knee joint, and saphenous nerve, which supplies the skin on the medial aspect of the lower leg.
Sensory and motor blockade are assessed to ensure the block’s effectiveness, with sensory testing using cold or pinprick and motor testing involving knee extension.
For the single-injection technique, local anesthetics like lidocaine or bupivacaine are commonly used.
It’s important to note that femoral nerve block may lead to weakness in the quadriceps muscle, affecting knee extension and weight-bearing, which should be explained to the patient. The use of a knee immobilizer can help reduce the risk of falls, especially after total knee arthroplasty.
Complications, such as hematoma or vascular puncture, can occur during the procedure and should be managed accordingly.
In summary, femoral nerve block is a straig lolhtforward and low-risk technique suitable for various surgical and pain management purposes in the thigh and lower leg, either alone or in combination with other nerve blocks for broader anesthesia of the lower limb.
The dosages for the local anesthetics commonly used in the single-injection technique of femoral nerve block:
1. Lidocaine 2.0%: 10 ml, containing 200 mg of lidocaine.
2. Sensocain (a brand of local anesthetic): 10 ml, containing 50 mg of the active ingredient.
3. Bupivacaine: 10 ml, containing 59 mg of bupivacaine.
These dosages are used for achieving surgical anesthesia and pain management in the specified procedures when performing a femoral nerve block. It’s essential to adhere to recommended dosages and follow proper medical guidelines when administering local anesthetics to ensure patient safety and effective pain control.
The femoral nerve block is a contemporary technique that has gained popularity recently. It offers distinct advantages over spinal anesthesia, especially for individuals who are elderly and have cardiac vulnerabilities. This method is particularly valuable as it minimizes the risk factors associated with spinal anesthesia, making it a preferred choice.
Femoral nerve blocks offer numerous benefits, especially for individuals with compromised cardiac function and those who arrive in the accident and emergency department with traumatic injuries such as bomb blasts or gunshot wounds to the legs. Severe pain can lead to cardiac arrest in these patients, but using this technique can potentially save lives. It not only reduces risks but also significantly improves recovery prospects. As a healthcare professional, I have extensively employed this technique, consistently witnessing remarkable positive outcomes.
I firmly believe that this technique should be implemented across all government hospitals to ensure widespread access to its benefits. Creating awareness about the advantages of femoral nerve blocks among medical practitioners and patients is essential. Its track record of safety and effectiveness makes it a valuable addition to modern healthcare practices, with minimal associated risks and maximum potential for improved patient outcomes.