الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Rising levels of knee osteoarthritis have led to increased overall incidence of TKR surgeries over the last decades. Most of TKR patients experiences moderate to severe postoperative pain .Untreated pain results not only in undue suffering but also causes higher incidence of cardiovascular complications, decreases the range of motion, delays ambulation and physiotherapy plans and increases the incidence of thromboembolic events. For decades, opioids and other pharmacological agents have been the mainstay for pain management after TKR. Their incomplete efficacy, dangerous side and the advances in US guided nerve block techniques are the reasons why concerns have been rising against their use as the main pain management modality for such patients. Being the central part of nerve supply to the knee joint, FNB has been considered a proven method for analgesia after TKR. However, it is not sufficient alone for complete pain relief and many approaches including sciatic nerve block (SNB), local anaesthetic infiltration (LIA) and obturator nerve block (ONB) have been employed as complementary analgesic methods for FNB to control pain after TKR.As posterior division of obturator nerve is the main ON contribution to posterior knee sensation and its selective block has less impact on total hip adductor function and is not covered in previous literature, this study was conducted to evaluate its effect when added to FNB on early (1st 24 postoperative hrs) pain control and early ambulation.
The aim of this work was to evaluate the effect of adding posterior obturator division block to femoral nerve block in terms of quality of pain relief (VAS scores and pethidine requirements) and the effect on postoperative ambulation and complications after TKR surgery.
The study was prospective, double blinded and randomized. It was carried out on 91 patients, of both sexes aged 40-70 years old admitted to ”Al Hadara University Hospital”, for knee arthroplasty. Patients were selected to be ASA class I, II & III after approval of Ethical Committee and written consent from every patient involved in the study.
Exclusion criteria
Patient refusal
Block site infections.
Allergy to local anaesthetic drug used.
Patients with lower limb neurological diseases, myopathies and recent DVT history.
Patients with morbid obesity (BMI>40 kg/m2).
Block failure
91 patients were randomized by closed envelope technique into two groups ; group FO (Femoral nerve block + posterior division obturator nerve block) 46 patients: received 20 mL of 0.25% bupivacaine as single shot for femoral nerve block plus 10 mL of 0.25% bupivacaine as single shot for obturator nerve posterior division block and group F (Femoral nerve block) 45 patients: received 20 mL of 0.25% bupivacaine as single shot for femoral nerve block alone.
• On the preoperative interview, full medical history was taken, full clinical examination was done and investigations including complete blood count, coagulation profile, liver function tests and kidney function tests. Moreover all patients were taught how to express pain intensity postoperatively using visual analogue score and examined for knee extension and hip adduction function of the limb planned for TKA and written consents were taken from every participant.
• Patients attached to multichannel monitor displaying continuous electrocardiography (ECG) monitoring for heart rate (beat/min) and detection of arrhythmias (lead II), non invasive arterial blood pressure (NIBP) in mmHg, arterial oxygen saturation (SpO2) and baseline data were recorded. All patients were premedicated with IV midazolam 10 minutes prior to block performance.
• Both blocks were performed in the supine position using high frequency US probe guidance after complete sterilization of the inguinal area with chlorohexidine .
• FNB was performed with the transducer parallel to the inguinal crease to obtain a short-axis view of the femoral nerve. A 22-gauge spinal needle was inserted in-plane through the fascia iliaca to the surface of the femoral nerve and 20 mL of 0.25% bupivacaine were injected to create a perineural fluid space. For obturator nerve posterior division block, the transducer was placed in the inguinal crease to identify the femoral artery and vein (starting from the same view of FNB). The transducer was then moved medially along the inguinal crease. After identification of the fascial planes of the pectineus and adductor muscles along the inguinal crease, local anaesthetic solution (10 ml of 0.25% bupivacaine) was injected between the adductor brevis and adductor magnus muscles.
• The efficacy of FNB was examined 15 minutes after injection by ice application (The ice was applied to the anterior aspect of the thigh and the medial aspect up to the medial malleolus below the knee) and the efficacy of obturator nerve block was tested 15 minutes after injection by weakness of thigh adductors by lang sphygmmomanometer test.
• Patients undergoing TKA were intubated after the induction of general anesthesia with intravenous propofol (2 mg/kg), fentanyl (1 microgram/kg) and rocuronium (0.6 mg/kg). General anesthesia was maintained with isoflurane (1.2%) and all patients received 1g paracetamol after induction. Patients received rescue dose of 25 mg pethidine as direct intravenous shot when intraoperative analgesia was required according to hemodynamic changes.
• After ending surgery, anaesthesia was discontinued, residual neuromuscular block was antagonized with atropine (0.01mg/kg) and neostigmine (0.04mg/kg). Patients extubated and transferred to post anaesthesia care unit (PACU) for next 24 hrs.
• All patients received 1g paracetamol every 8 hrs starting from the first dose given after induction of anaesthesia.
• All patients received 25 mg pethidine as direct intravenous shot when analgesia was requested by the patient or if VAS score was 4 or more .
The following measurements were carried out:
• Demographic data (age, sex, weight, height and BMI) were measured.
• Intraoperative hemodynamic parameters in terms of heart rate (HR) and systolic blood pressure (SBP) were recorded 10 minutes after induction of anaesthesia as intraoperative baseline records, at time of incision and at 15 minutes intervals during surgery.
• Visual analogue scale (VAS) was performed at rest and during activity (45° flexion of the postoperative knee) at 2, 4, 6 hours postoperatively and then every 6 hrs for the 1st 24 hrs, with scores ranging from 0 (no pain) to 10 (worst imaginable pain)
• Time of first request for analgesia: (25 mg pethidine was given as direct intravenous shot).
• Total analgesic requirements: total dose of pethidine received was calculated for each patient.
• Assessment of quadriceps muscle strength was performed at 2, 4, 6 hours postoperatively and then every 6 hrs for the 1st 24 hrs .
• Time of first straight leg raise up test (SLR):was assessed hourly after 6 hrs postoperative till the time of first successful test.(137)
• Timed up and Go test at 24 hrs .
• Short assessment of patient satisfaction SAPS (for quality of the block) was performed after 24 hrs .
• Incidence of side effects as PONV, local anaesthetic toxicity ,delayed ambulation and falls were recorded.
• Duration of anaesthesia and duration of surgery were measured .
The following results were obtained:
• Comparing the two groups there were no significant statistical differences in demographic data, weight, height and BMI. Also, duration of surgery and anaesthesia in the two groups had no significant difference.
• There were no significant differences in HR, MABP and O2 saturation at preoperative time, after induction of anaesthesia and all through the intraoperative and postoperative periods among the two groups.
• Regarding pain intensity, comparing mean VAS rest and VAS motion of two groups statistically, there was no significant difference between the two groups at 2, 4, 6, 12 hours, but there was statistically significant difference at mean VAS (both rest and motion at 18 and 24 hours with less pain scores in the FO group at these times. P value 0.014 and 0.005 for VAS rest at 18 and 24 hrs respecively and 0.010 and 0.006 for VAS motion at 18 and 24 hrs respectively.
• There was no significant difference in regards of the mean time of first analgesic request, but there was significant difference in mean of the total required doses of pethidine which is significantly more in the F group with P value of 0.007.
• During the assessment of motor function of the operated limb there were no statistically significant difference in mean values of knee extension srength, time of first straight leg raise test and timed up and go test .
• Patient satisfaction was significantly higher in the FO group.
• Incidence of complications of the two groups showed statistically significant difference regarding PONV as the incidence is significantly higher in F group when compared to the FO group (p value of 0.048). No falls during ambulation, local anaesthetic toxicity or block site hematoma was recorded in any patient of the study.