الفهرس 
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Abstract
summary
he Lumbar Plexus describes the association of nerves derived from the segmental lumbar spinal roots. The lumbar plexus receives input from L1 (variable input from T12) to L4 and produces the femoral nerve, lateral cutaneous nerve of the thigh, obturator nerve, as well as the iliohypogastric, ilioinguinal and genitofemoral nerves.
This block is mainly indicated for the management of pain following unilateral lower limb surgery principally of the knee, femur or hip. It is less useful as a sole anaesthetic technique because there is no blockade of the sciatic nerve, which has major innervation of the posterior thigh, the lower leg and usually has some innervation of both the hip and knee joint. Thus complete anaesthesia or analgesia of the whole lower limb requires the addition of a sciatic nerve block Alternatives for providing regional anaesthesia or analgesia of the lower limb are central neuroaxial blockade: Epidural or Sub-Arachnoid (spinal) technique.
These techniques generally produce bilateral effects such as reduced mobility, which may be undesirable or unnecessary, and are frequently associated with the risk of urinary retention. They also have their own risks and complications, especially the feared epidural haematoma or abscess.
T
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Identification of the lumbar plexus
Loss of resistance
The early descriptions of lumbar plexus blocks describe a ―loss of resistance‖ on passing through the fascia of the psoas major muscle. Whilst these techniques, along with paraesthesia, are not part of modern regional anaesthesia, a ―pop‖ can be felt with a short bevelled needle.
Peripheral nerve stimulation
Nerve stimulation is an established method of nerve localization during application of peripheral nerve blocks. It is generally accepted that the electrical current at the tip of the insulated needle evokes a motor response before the needle makes a contact with or enters the nerve
COMPLICATIONS OF LUMBAR PLEXUS BLOCK
Direct trauma to nerves, Intra-neural injection, Damage to abdominal viscera, Retro –peritoneal haematomas, Psoas abscess, Epidural spread, Intravascular injection and LA toxicity.
For patients receiving anticoagulation undergoing deep plexus or deep peripheral block, recommendations regarding neuraxial techniques should be similarly applied.
For nearly 6 decades ultrasonography has contributed to clinical medicine. It is gaining popularity in the practice of
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anesthesia through its unique ability to noninvasively image structures.
Ultrasound guidance in anesthesia is receiving a great deal of attention. Current research suggests that it has many attributes, especially for the application of regional anesthesia procedures. Sonography addresses a variety of concerns, such as patient safety and comfort, cost-effectiveness, time to complete a procedure, and success rates associated with invasive anesthesia procedures.
Ultrasound guidance is commonly being used for the placement of nerve blocks, placement of peripheral and central lines, and arterial catheterization. Recently, it has been applied to preprocedural and imaged-guided spinal and epidural placement. It seems that ultrasound has kindled interest into the performance of relatively new peripheral nerve blocks as well.
Ultrasound guidance during PCB may offer several advantages compared to the traditional methods. The related anatomy and target structures are clearly identified, the advancement of the needle to the posterior part of the psoas muscle and mean while the spread of the LA during the injection can be observed. This may allow the anesthesiologist to perform the PCB safely and successfully.