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Sciatic Nerve Block - Popliteal Region

NEEDLE INSERTION

 

Alternate Body Positions For Needle Insertion

 

The supine position is suitable for the in plane (IP) needle approach.
The lateral decubitus position is suitable for both the IP and out of plane approaches.

 

CATHETER INSERTION

  • Continuous popliteal sciatic nerve block (CPSNB) is indicated for foot and ankle analgesia (see Catheter Technique)
  • The out of plane needle insertion approach is generally recommended for CPSNB in a patient lying prone.
  • The goal is to place the needle and the catheter proximal to the site where the sciatic nerve divides so that both the peroneal and tibial nerves will be anesthetized.
  • Injection of local anesthetic or D5W solution (if nerve stimulation is desired) through the needle to distend the perineural space is recommended to facilitate the ease of catheter advancement.
  • Aim to advance the catheter 3-5 cm into the perineural space with or without nerve stimulation guidance.
  • It is often difficult to capture the transverse view of the catheter as it is advanced with the Out of Plane approach.
  • Local anesthetic spread can be observed in real time during catheter injection.
  • Suboptimal catheter position may be corrected by withdrawing the catheter a short distance before further local anesthetic is injected.
A. Patient preparation, sterile draping and pre-block scanning
B. Out of plane needle advancement under ultrasound guidance
C. Catheter insertion with the help of an assistant
D. Catheter exits in the distal 1/3 part of the thigh
E. Catheter is secured with dermabond at the exit site
F. Catheter is further secured with a transparent dressing
A. Pre-block transverse scan

 

Arrowheads = sciatic nerve

 

PA = popliteal artery

B. Hydro dissection distends the perineural space

 

Arrow = block needle in cross section.

C. Arrows = catheter track
D. Circumferential local anesthetic (LA) spread is visualized around the sciatic nerve
E. A longitudinal scan shows local anesthetic (LA) on both sides of the nerve (arrowheads)

 

Arrows = catheter

F. Another longitudinal scan shows the catheter (arrows) and its tip (CT)

 

IMAGE GALLERY

 

1. Improper Local Anesthetic Spread Outside the Fascial Sheath

 

Arrowheads = sciatic nerve

 

Asterisk = improper local anesthetic spread outside the fascial sheath

 

2. Proper Circumferential Local Anesthetic Spread Inside the Fascial Sheath

 

Arrowheads = sciatic nerve
Arrowheads = sciatic nerve

 

Asterisks = local anesthetic spread

 

3. Visualization of the Popliteal Vein

 

Arrowheads = sciatic nerve

 

PA = popliteal artery

Arrowheads = sciatic nerve

 

PA = popliteal artery

 

PV = popliteal vein

 

VIDEO GALLERY

 

Popliteal Sciatic Nerve Block (Out of Plane Approach)

 

Popliteal Sciatic Nerve Block (Out of Plane Approach) 2

 

Popliteal Sciatic Nerve Block with Catheter Longitudinal View (In Plane Approach)

 

Popliteal Sciatic Nerve Split

 

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SELECTED REFERENCES

  • Domingo-Triado V, Selfa S, Martinez F, Sanchez-Contreras D, Reche M, Tecles J, Crespo MT, Palanca JM, Moro B: Ultrasound guidance for lateral midfemoral sciatic nerve block: a prospective, comparative, randomized study. Anesth.Analg. 2007; 104: 1270-4.
  • Oberndorfer U, Marhofer P, Bosenberg A, Willschke H, Felfernig M, Weintraud M, Kapral S, Kettner SC: Ultrasonographic guidance for sciatic and femoral nerve blocks in children. Br.J.Anaesth. 2007; 98: 797-80.
  • Saranteas T, Chantzi C, Zogogiannis J, et al. Ultrasound examination and localization of the sciatic nerve at the mid-femoral. An imaging study with ultrasound. Acta Anaesthesiol Scand 2007;51:387-8.
  • Khabiri B, Arbona F, Norton J: "Gapped supine" position for ultrasound guided lateral popliteal fossa block of the sciatic nerve. Anesth.Analg. 2007; 105: 1519.
  • Swenson JD, Bay N, Loose E, Bankhead B, Davis J, Beals TC, Bryan NA, Burks RT, Greis PE: Outpatient management of continuous peripheral nerve catheters placed using ultrasound guidance: an experience in 620 patients. Anesth.Analg. 2006; 103: 1436-43.
  • Tsui BC, Finucane BT: The importance of ultrasound landmarks: a "traceback" approach using the popliteal blood vessels for identification of the sciatic nerve. Reg Anesth.Pain Med. 2006; 31: 481-2.
  • Gray A T, Huczko E L, Schafhalter-Zoppoth I. Lateral popliteal nerve block with ultrasound guidance. Reg Anesth Pain Med 2004;29: 507-509.
  • McCartney C J, Brauner I, Chan V W. Ultrasound guidance for a lateral approach to the sciatic nerve in the popliteal fossa. Anaesthesia 2004;59: 1023-1025.
  • Minville V, Zetlaoui P J, Fessenmeyer C, Benhamou D. Ultrasound guidance for difficult lateral popliteal catheter insertion in a patient with peripheral vascular disease. Reg Anesth Pain Med 2004;29: 368-370.
  • Schafhalter-Zoppoth I, Younger S J, Collins A B, Gray A T. The "seesaw" sign: improved sonographic identification of the sciatic nerve. Anesthesiology 2004;101: 808-809.
  • Sinha A, Chan V W. Ultrasound imaging for popliteal sciatic nerve block. Reg Anesth Pain Med 2004;29: 130-134.
  • Sites B D, Gallagher J D, Tomek I, Cheung Y, Beach M L. The use of magnetic resonance imaging to evaluate the accuracy of a handheld ultrasound machine in localizing the sciatic nerve in the popliteal fossa. Reg Anesth Pain Med 2004;29: 413-416.
  • Sites B D, Gallagher J, Sparks M. Ultrasound-guided popliteal block demonstrates an atypical motor response to nerve stimulation in 2 patients with diabetes mellitus. Reg Anesth Pain Med 2003;28: 479-482.