Psoas Sciatic Blockade for Knee Arthroplasty
Condition: Knee Osteoarthritis
MeSH terms: Osteoarthritis; Osteoarthritis, Knee
Study type: Interventional

Summary: 
      Objectives: To compare the efficacy of continuous combined psoas sciatic block as a sole
      anaesthetic technique with conventional combined spinal epidural anesthesia for patients
      undergoing total knee arthroplasty.

      Subjects and Method: Eighty patients ASA (American society of anaesthesiologists
      classification) I to III with age range from 50 to 65 years old and scheduled for total knee
      replacement were included in the study. Subjects were divided into two groups; the first
      group (Pso/sci) received ultrasound guided with the use of nerve locator continuous psoas
      sciatic block and the second group (CSE) received combined spinal epidural anesthesia. Onset
      of sensory and motor block time, hemodynamic changes, contra-lateral spread, first time need
      for analgesia, incidence of complications, and patient and surgeon satisfactions were
      recorded.
    

Detailed description: 
      After approval of the ethics committee, department of anaesthesia, Menoufia university and
      written informed consent, 80 patients undergoing unilateral total knee arthroplasty were
      randomly allocated into two groups. The first group (40 patients) received continuous psoas
      compartment block combined with continuous sciatic block (Pso/Sci group) and the second group
      (40 patients) received combined spinal epidural anaesthesia (CSE group). All patients were
      between 50 and 65 years old with an American society of anaesthesiologists classification
      (ASA status) of I to III. Patients' exclusion criteria included contraindication of regional
      anesthesia, bleeding disorders, localized infection, neurological deficit, substance
      dependence, and uncooperative patients. Upon arrival to the operative theater patients were
      attached to the standard monitoring and an intravenous cannula was inserted. All patients
      received 1 - 2 mg midazolam for sedation before the blocks.

      Sciatic nerve blockade:

      The block was done under complete aseptic technique. The patient was positioned in the
      lateral recumbent position with the operative side up and the hips and knees were flexed. The
      greater trochanter, posterior superior iliac spine and sacral hiatus were palpated and
      marked. Curvilinear low frequency U/S probe 2-5 MHz, (Sonosite, M-Turbo, Sonosite Inc., USA)
      was used for scanning. The probe was placed transversely in the middle of the line connecting
      the greater trochanter and sacral hiatus. The hip joint and the ischial spine were seen as
      hyperechoic lines in the lateral and medial sides respectively and the sciatic nerve was
      appeared as a triangular or flattened hyperechoic structure under the gluteus maximus. Local
      infiltration with 1 ml lidocaine 2% with 27-gauge needle was done before introducing the 100
      mm 18 gauge sterile insulating pajunk needle (PAJUNK, PlexoLong, Germany) for the block.

      The pajunk needle was connected to a nerve stimulator (Plexygon, Vygon Italia, Padua, Italy)
      with 0.8 mA initial current and inserted out of plane reaching the sciatic nerve until
      eliciting either planter flexion or dorsiflexion with reduced current output up to 0.2 mA. A
      mixture of 15 ml lidocaine 1% and 15 ml bupivacaine 0.25% were injected around the sciatic
      nerve. A multi-perforated reinforced catheter was inserted through the needle and advanced 5
      cm distal to the needle tip to provide continuous infusion. The needle was removed and the
      catheter was fixed to the skin.

      Psoas compartment blockade:

      The block was done under complete aseptic technique. The patient was positioned in the
      lateral recumbent position with the operative side upper most and hip and knee were flexed.
      L4-5 space was identified and marked by a line passing between the iliac crest and vertebral
      column. The puncture point for the block was marked 5 cm lateral to the L4-5 space within the
      drawn line. Using curvilinear low frequency U/S probe 2-5 MHz, (Sonosite, M-Turbo, Sonosite
      Inc., USA) the area was scanned longitudinally starting from the sacrum and moving cranially
      to identify the 4th transverse process then turned transversally in a rocking manner
      laterally to the end of the transverse process. The skin at the site of entry was infiltrated
      with 1 ml lidocaine 2% using 27-gauge needle. A 100 mm 18 gauge insulating pajunk needle
      (PAJUNK, PlexoLong, Germany) connecting to a nerve stimulator (Plexygon, Vygon Italia, Padua,
      Italy) with 0.8 mA initial current was advanced from medial to lateral proximal to the
      transverse process of L4 then advanced caudally to it until eliciting the quadriceps femoris
      contraction. When the contraction was persisted with reduced current down to 0.2 mA, a
      mixture of 20 ml lidocaine 1% and 20 ml bupivacaine 0.25% were injected after repeated
      negative aspiration. A multi-perforated reinforced catheter was inserted through the pajunk
      needle and was advanced 5 cm distal to the needle tip. The needle was removed and catheter
      was fixed to the skin.

      Combined spinal epidural block:

      The patient was in the sitting position, L3-4 space was marked then the area was sterilized
      and draped. Local anaesthetic (LA) was applied in the track by 27 gauge needle with 5 ml
      Lidocaine 1%. With portex combined spinal epidural kit needle through needle (PORTEX, Smiths
      Medical ASD, Inc., USA), the epidural space was detected by loss of resistance technique with
      saline then 27 gauge 120 mm pencil point spinal needle passed through the epidural needle
      till perforating the dura and observing the cerebrospinal fluid, 2.5 ml (12.5 mg) of heavy
      bupivacaine 0.5% (Bupivacaine hydrochloride 0.5%, 5mg/ml, AstraZeneca) was injected. The
      needle was removed and the epidural catheter was advanced 4 cm distal to the needle tip and
      fixed to the skin.

      After block was done all the patients returned back to the supine position, the sensory block
      was assessed by cold perception using ice backs and the motor block was assessed by Bromage
      scale (3=no flexion of hip, knee and foot; 2=no flexion of hip and knee with foot flexion;
      1=no flexion of hip with flexion of knee and foot; 0=full flexion of hip, knee and foot).
      Sensory and motor blocks were assessed every 10 minutes for 3 times. Bilateral assessment was
      done to detect epidural spread of local anesthetics. Failure to establish adequate sensory
      and motor blocks after 30 minutes, a failed block was considered and general anesthesia was
      induced if there were no contraindications and the patient was excluded from the study.

      In both groups, the time taken to finish the block was recorded. The onset of sensory and
      motor blocks were recorded which was defined as the time from finishing the blockade to the
      occurrence of the block.

      In the post-operative period, the duration of the sensory block for both groups was recorded
      which was defined as the time between the onset of the block and the asking for first
      analgesia. Once the patient experienced pain (VAS ≥ 3), a bolus of 5 ml Lidocaine 2 % was
      injected in both catheters in (pso/sci) group and epidural catheter in (CSE) group then
      continuous LA infusion was followed using a solution of 0.125 % Bupivacaine in a rate of 7-10
      ml/hour according to the patient response. Heart rate and blood pressure were recorded every
      5 minutes all through the procedures; bradycardia and hypotension were considered if the
      heart rate and the mean blood pressure were 30% below the starting baseline. Bradycardia was
      treated by IV 0.5 mg atropine and hypotension was managed by 10- 15 mg IV ephedrine. Intra-
      and post-operative side effects like bradycardia, hypotension, nausea and vomiting were
      recorded. Age, gender, weight, ASA class and duration of surgery (time from skin incision
      until skin closure) were recorded. Data was analyzed using SSPS software 12.0 (SSPS Inc.,
      Chicago, IL, USA) and represented as mean ± standard deviation and p value less than 0.05 was
      considered to be statistically significant.
    

Intervention name(s): Bupivacaine 0.25%; Pajunk Needle; Portex combined spinal epidural kit; Lidocaine 1%; Bupivacaine 0.5%; Lidocaine 2 %; Bupivacaine 0.125 %
Intervention type(s): Drug; Other; Other; Drug; Drug; Drug; Drug
Intervention description(s): For psoas sciatic block.; For local anaesthesia application in psoas sciatic block; For combined spinal epidural anaesthesia; For psoas sciatic block.; For spinal anaesthesia in combined spinal epidural anaesthesia.; For psoas sciatic block in the post-operative period; For combined spinal epidural in the post-operative period.
Other intervention name(s): Bupivacaine; Lidocaine; Bupivacaine; Lidocaine; Bupivacaine
Intervention MeSH terms: Lidocaine; Bupivacaine
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Other
Keywords: Total knee replacement; Psoas Sciatic block; Epidural anaesthesia