Ovid: Peripheral Nerve Blocks: A Color Atlas

Continuous Lumbar Plexus Blocks

Maria Matuszczak

Didier Sciard

A. Psoas Compartment Approach

Patient Position: Lateral, with the side to be blocked upright.

Indications: Anesthesia and postoperative analgesia for hip, femur, or knee surgery.

Needle Size and Catheter: 18-gauge, 38-, 50-, or 100-mm insulated introducer needle, and a 20- or 21-gauge catheter.

Skin–Nerve Distance: 2.5 cm at one year, increasing to 8.0 cm in adolescents. Distance from skin to lumbar plexus depends also on the weight (Fig. 59-1).

Volume and Infusion Rate: (Table 59-1); maximum initial bolus volume of ropivacaine 0.2%. Dosage of ropivacaine 0.2% for continuous infusion: 0.4 to 0.5 mg/kg/h.

Anatomic Landmarks: The highest point on the iliac crest is identified. A line is drawn from this point to the spine processes (SP). The posterior superior iliac spine (PSIS) is identified. A parasagital line to the vertebral spine is drawn passing through the posterior superior iliac spine. The intersection of these two lines is the point of insertion of the introducer needle (Figs. 59-2, 59-3).

Approach and Technique: The needle is introduced perpendicular to the skin or lightly directed posteriorly in an appropriately anesthetized/sedated child. After bone contact with the transverse process of L4 or L5, the needle is redirected to the cranial or caudal direction (angle between 30 and 45 degrees) and 1 cm deeper until a contraction of the quadriceps (femoral n.) is elicited. With an appropriate muscle response still present at a current of 0.5 mA and after negative aspiration for blood the appropriate amount of local anesthetic solution is slowly injected. Maintaining the introducer needle in the same

P.385

position, the catheter is threaded 2 cm beyond the needle tip. The introducer needle is removed and the catheter is secured in place with benzoin and a transparent adhesive dressing. Blood pressure has to be monitored because of a possible epidural or subarachnoid injection. The absence of epidural spread is assessed by the presence of an adequate reaction to pinprick of the opposite leg after emergence.

Figure 59-1. Distance skin to lumbar plexus.

Tips

This block should only be performed by an anesthesiologist trained in pediatric regional techniques.
The technique described above is Winnie's approach; we do not use Chayen's approach because of a higher incidence of epidural spread reported in the literature.
The shortest needle that can easily reach the plexus has to be used because of the potential risk of visceral organ (kidney) puncture.
Ultrasound guidance can help to determine the depth of the lumbar plexus.
Peritoneal or visceral infection, trauma to the lumbar spine, lumbar vertebral deformities, and coagulopathy are contraindications for this block.
A slow injection (1 mL/10 seconds) of the local anesthetic is advised.
The absence of epidural spread is assessed by the presence of an adequate reaction to a pinprick of the opposite leg after emergence from anesthesia.
A stimulating catheter can be used in older children.

Table 59-1. Maximum Initial Bolus Volume of Ropivacaine 0.2%—Psoas Compartment Approach

kg	2–10 kg	15 kg	20 kg	25 kg	30 kg	40 kg	50 kg	60 kg	70 kg
mL	1 mL/kg	12.5 mL	15 mL	17.5 mL	20 mL	23 mL	25 mL	25 mL	30 mL

P.386

Figure 59-2. Lumbar plexus landmarks.

Figure 59-3. Lumbar plexus catheter placement.

Suggested Readings

Chayen D, Nathan H, Chayen M. The psoas compartment block. Anesthesiology 1976;45:95–99.

Dadure C, Capdevila X. Continuous peripheral nerve blocks in children. Best Pract Res Clin Anaesthesiol 2005;19(2):309–321.

Dadure C, Pirat Ph, Raux O, et al. Perioperative continuous peripheral nerve blocks with disposable infusion pumps in children: A prospective descriptive study. Anesth Analg 2003;97:687–690.

Dadure C, Raux O, Gaudard P, et al. Continuous psoas compartment blocks after major orthopedic surgery in children: a prospective computed tomographic scan and clinical studies. Anesth Analg 2004;98(3):623–628.

Dalens B. Regional anesthesia in infants, children, and adolescents. Baltimore: Williams & Wilkins, 1995.

Dalens B, Tanguy A, Vanneuville G. Lumbar plexus block in children. Comparison of two procedures in 50 patients. Anesth Analg 1988;67:750–758.

Ivani G, Mossetti V. Continuous peripheral nerve blocks. Paediatr Anaesth 2005;15:87–90.

Marhofer P, Frickey N. Ultrasonographic guidance in pediatric regional anesthesia. Part 1: theoretical background. Paediatr Anaesth 2006;16(10):1008–1018.

Roberts S. Ultrasonographic guidance in pediatric regional anesthesia. Part 2: techniques. Paediatr Anaesth 2006;16:1125–1132.

Sciard D, Matuszczak M, Gebhard R, et al. Continuous posterior lumbar plexus block for acute postoperative pain control in young children. Anesthesiology 2001;95:1521–1523.

P.387

B. Continuous Femoral Nerve Block

Patient Position: Supine; the leg to be blocked slightly abducted.

Indications: Preoperative analgesia for fractured femur with leg in traction. Anesthesia and postoperative analgesia for femur and knee surgery; postoperative physiotherapy and complex regional pain syndrome.

Needle Size and Catheter: 18-gauge, 25-, 38-, or 50-mm insulated introducer needle, and 20- or 21-gauge catheter.

Skin–Nerve Distance: 0.5 cm at one year, increasing to 2.0 cm in adolescents (Fig. 59-4).

Volume and Infusion Rate: (Table 59-2); maximum initial bolus volume of ropivacaine 0.2%. Dosage of ropivacaine 0.2% for continuous infusion: 0.4 to 0.5 mg/kg/h.

Anatomic Landmarks: The anterior iliac spine, the pubic tubercle (inguinal ligament), and the femoral artery.

Approach and Technique: The insertion point is lateral to the femoral artery pulse and 1 to 3 cm below the inguinal ligament. The introducer needle is advanced parallel to the femoral artery in an appropriately anesthetized/sedated child. When a contraction of the vastus intermedius is elicited and still present at 0.5 mA, the appropriate dose of local anesthetic is slowly injected after negative aspiration for blood. Maintaining the introducer needle in the same position, the catheter is threaded 2 cm beyond the needle tip. The introducer needle is removed and the catheter is secured in place with benzoin and a transparent adhesive dressing (Figs. 59-5, 59-6).

Tips

A femoral nerve block can be performed with the leg in many positions as long as it is possible to locate the femoral artery and the inguinal ligament.
The catheter should not be thread more than 3 cm.

Easy block to perform even outside the operative room.

Figure 59-4. Distance skin to femoral nerve.

P.388

Table 59-2. Maximum Initial Bolus Volume of Ropivacaine 0.2%—Continuous Femoral Nerve Block

kg	2–10 kg	15 kg	20 kg	25 kg	30 kg	40 kg	50 kg	60 kg	70 kg
mL	1 mL/kg	10 mL	12 mL	15 mL	15 mL	17.5 mL	20 mL	20 mL	25 mL

This block is perfectly indicated for femur fracture with the leg in traction.
Ultrasound can be used to localize the femoral nerve, to position the needle, and to verify that the local anesthetic is injected via the catheter around the nerve.
A stimulating catheter can be used in older children.

Figure 59-5. Femoral nerve block landmarks.

Figure 59-6. Femoral catheter placement.

P.389

Suggested Readings

Dalens B. Regional anesthesia in infants, children, and adolescents. Baltimore: Williams & Wilkins, 1995.

Johnson CM. Continuous femoral nerve blockade for analgesia in children with femoral fractures. Anaesth Intens Care 1994;22:281–283.

Marhofer P, Frickey N. Ultrasonographic guidance in pediatric regional anesthesia. Part 1: theoretical background. Paediatr Anaesth 2006;16(10):1008–1018.

Roberts S. Ultrasonographic guidance in pediatric regional anesthesia. Part 2: techniques. Paediatr Anaesth 2006;16:1125–1132.

Tobias JD. Continuous femoral nerve block to provide analgesia following femur fracture in a pediatric ICU population. Anaesth Intens Care 1994;22:616–618.

P.390

C. Continuous Fascia Iliaca Compartment Block

Patient Position: Supine. The leg to be blocked may be slightly abducted.

Needle Size and Catheter: 18-gauge, 25- or 50-mm introducer needle, and a 20- or 21-gauge catheter. No stimulating needle needed.

Skin–Nerve Distance: 1.2 cm at one year, increasing to 2.5 cm in adolescents (Fig. 59-7).

Volume and Infusion Rate: (Table 59-3); maximum initial bolus volume of ropivacaine 0.2%. Dosage of ropivacaine 0.2% for continuous infusion: 0.4 to 0.5 mg/kg/h.

Anatomic Landmarks: The anterior superior iliac spine, and the pubic tubercle.

Approach and Technique: The anterior iliac spine and the pubic tubercle are identified. A line is drawn between these two landmarks, demarcating the inguinal ligament. The junction of the lateral third and the medial two-thirds of this line is marked. The insertion point of the needle is 0.5 cm to 1.0 cm caudally to the junction marked and lateral to the femoral artery. The needle is introduced perpendicular to the skin. A first loss of resistance is felt when the needle passes through the fascia lata, and a second loss of resistance is felt when the needle passes through the fascia iliaca. After negative aspiration for blood the appropriate volume of local anesthetic is slowly injected. Maintaining the introducer needle in the same position, the catheter is threaded 2 cm beyond the needle tip. The introducer needle is removed and the catheter is secured in place with benzoin and a transparent adhesive dressing (Fig. 59-8).

Tips

Easy block to perform by beginners.
The nerve stimulator is not needed, no painful movements of fractured extremity.
In children, according to the literature, the fascia iliaca block has a greater success rate compared to the femoral block.

Figure 59-7. Distance skin to fascia iliaca compartment.

P.391

Table 59-3. Maximum Initial Bolus Volume of Ropivacaine 0.2%—Continuous Fascia Iliaca Compartment Block

kg	2–10 kg	15 kg	20 kg	25 kg	30 kg	40 kg	50 kg	60 kg	70 kg
mL	1 mL/kg	12.5 mL	15 mL	17.5 mL	20 mL	22.5 mL	25 mL	25 mL	30 mL

Figure 59-8. Fascia iliaca landmarks.