Outpatient Lower Extremity Orthopedic Surgery Utilizing Single Injection Psoas
and Parasacral Sciatic Nerve Blocks. A Case Report.
Jason G. Ramirez, MD Tim Litofe, MD, and F. Kayser Enneking MD.
Department of Anesthesiology, University of Florida

Background/Objectives: Regional anesthetic techniques are invaluable for patients undergoing ambulatory surgery. Peripheral nerve blocks provide excellent surgical anesthesia, postoperative analgesia and decrease the incidence of postoperative nausea and vomiting (PONV).(1) PONV and pain are detrimental to patient care and also have important economic implications as they increase the amount of time spent in the recovery unit. The decision to discharge a patient home with a lower extremity nerve block, however, can be quite controversial. Patients with residual motor blockade may be unable to ambulate safely, putting them at an increased risk of falls and injury.(2) An ideal peripheral nerve block would: maximize the sensory and motor blockade throughout the surgical procedure, provide postoperative analgesia and allow for rapid motor recovery. In the post anesthesia care unit (PACU), the patient should exhibit enough residual motor function to facilitate ambulation while receiving adequate pain control.
We present a case report describing the use of a long acting psoas compartment block combined with a short acting parasacral sciatic nerve block in a patient undergoing a right distal femur exostosis excision at an ambulatory surgical facility. A psoas compartment block using 0.25% bupivacaine was chosen for the purpose of intraoperative anesthesia and long acting post-operative analgesia with minimization of motor blockade. Chloroprocaine 3% was selected for the sciatic block offering the advantage of short acting anesthesia with rapid recovery of motor function to facilitate early discharge from the hospital.
Methods: A psoas compartment block, described by Capdevila, was used to block the lumbar plexus.(3) A quadriceps muscle twitch was elicited at 0.34 mA using a Braun Stimuplex Dig RC nerve stimulator. Using a 10 cm Pajunk 21 G insulating needle, 20 mL of 0.25% bupivacaine (with 1:400,000 epinephrine and clonidine 50 mcg) was placed. A parasacral approach to the sciatic nerve, as described by Gaertner, was identified using a Pajunk needle and a Braun nerve stimulator as above.(4) Plantar flexion was elicited with
0.31 mA, and 20 mL of 3% Chloroprocaine (with 1:400,000 epinephrine and clonidine 50 mcg) was injected. The patient (90kg) received 4mg of midazolam and 200 mcg of fentanyl during the block procedure for anxiolysis and comfort. Intraoperatively, the patient received an additional 3 mg of midazolam. A propofol infusion was maintained at 25-50mcg/kg/min during the procedure. The operative procedure lasted 46 min afterwhich the patient was taken to the PACU. Recovery time was 40 minutes during which supplemental pain and/or antiemetic medication was not required.
Results: This combination nerve block resulted in successful surgical anesthesia and post-operative analgesia. This was demonstrated by minimal intraoperative supplementation, absence of analgesic medication requirements in the PACU and rapid recovery. Shortly after the procedure the patient was able to ambulate using crutches and was discharged home with a prescription for oral pain medications as needed.
Conclusion: Combined psoas compartment and sciatic single injection nerve blocks using a combination of short and long acting local anesthetics can be used successfully for intraoperative anesthesia, post-operative analgesia, and early discharge in patients undergoing outpatient lower extremity orthopedic surgery.

1. Nielsen KC, Steele SM. Outcome after regional anaesthesia in the ambulatory setting – is it really worth it? Best Practice & Research Clinical Anaesthesiology. 2002 16 (2):145-157
2. Klein SM, Pietrobon R, Nielsen KC, Warner DS, Greengrass RA, Steele SM. Peripheral nerve blockade with long-acting local anesthetics: a survey of the Society for Ambulatory Anesthesia. Anesth Analg. 2002 Jan;94(1):71-6
3. Capdevila X, Macaire P, Dadure C, Choquet O, Biboulet P, Ryckwaert Y, D'Athis F. Continuous psoas compartment block for postoperative analgesia after total hip arthroplasty: new landmarks, technical guidelines, and clinical evaluation. Anesth Analg. 2002 Jun;94(6):1606-13
4. Gaertner E, Lascurain P, Venet C, Maschino X, Zamfir A, Lupescu R, Hadzic A. Continuous parasacral sciatic block: a radiographic study. Anesth Analg. 2004 Mar;98(3):831-4

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