Application Of Ultrasound Guided Lumbar Plexus-sciatic Nerve Blocking In Knee Arithroscopic Surgeries Of Elderly Patients

Background and objectiveKnee arithroscopic surgeries are common for the elderly patients. The methods of anesthesia are various, but in recent years ultrasound guided lumbar plexus-sciatic nerve combined blocking has gained increasing interests for its minimal interference on hymodynamics, exactly anesthetic effect, longer duration of analgesia and fewer adverse reactions. The gastrointestinal and urinary function are not affected, so the urinary canal is not necessary. Compared with the continuous epidural anesthesia, its advantage is obvious. However, the traditional peripheral nerve block technology is performed blindly. Most anesthetists still mainly depend on the different feeling or nerve stimulator to locate nerve during the lumbar plexus-sciatic nerve combined blocking. For the obese patients and the patients with anatomical variations, inaccurate location and the failure of puncture often appear. With the increasing development of ultrasonic technology, ultrasonography of peripheral nerve has become a reality and the way of peripheral nerve block is changed fundamentally. Ultrasound guided peripheral nerve block possess better efficacy, less postoperation complications and a higher success rate. Ultrasound-guided nerve block will lead a technical innovation in anesthesia field.The elderly patients undergoing knee arithroscopic surgeries were employed in this study. The study was to investgate interference on hymodynamics, the degree of sensory and motor nerve block, occurring of complications for ultrasound guided lumbar plexus-sciatic nerve combined blocking.Material and methodsFollowing Ethical Committee of the first affiliated hospitals of Zhengzhou University approval and informed consent,60 elderly patients undergoing unilateral knee arithroscopic surgeries, ASA I～Ⅱwere randomly devided into two groups with 30 cases each:group N (ultrasound guided lumbar plexus-Sciatic nerve combined blocking) and group E (continuous epidural anesthesia).Monitor NBP, ECG and SpO2. Fentanyl 0.5-1μg/kg and midazolam 1-3mg intravenous before puncture. The puncture was performed by the veteran anesthetist and the data were recorded by another anesthetist. Ultrasound-guided lumbar plexus and sciatic nerve block of group N was obtained respectively with 0.5% ropivacaine 23-26ml and 16-18ml. The routine epidural puncture was performed at L2-3 and the local anesthetic(0.5% ropivacaine) were injected by different times(15-17ml). If anesthesia could not satisfy the requirement of the surgeries, propofol and fentanyl were injected to sedation and analgesia. Accelerate the fluid influsion if the NBP of the patients was decreased during anesthesia. Ephedrine 5-10mg were injected if SBP was lower than 90 mmHg.The following indicatrixes were observed and recorded:1. The images of ultrasound guided lumbar plexus-sciatic nerve combined blocking2. The hemodynamic parameters before puncture (To) and 5min (T1),15 min (T2),30 min (T3),45 min (T4),60 min (T5) after the injection of local anesthetic.3. The volume of fluid influsion during anesthesia4. The dosage of ephedrine5. The degree of sensory and motor nerve block6. the block efficacy during operations7. the VAS grade at 1,4,8 hours after operations8. The occurring of Adverse reactionAll the data were processed with SPSS 12.0 package. The measurement data were analyzed by normality test.Results1. General material:Age, height, weight, sex and operation time between the two groups were not statistically significant (P>0.05)2. The images of ultrasound guided lumbar plexus-Sciatic nerve combined blockingUltrasound guidance technology could clearly show lumbar plexus, sciatic nerve and its anatomical surrounding. The process could be demonstrated and clearly observed during the performance. The advancement of needle and the spread of local anesthetic could be monitored under ultrasound.3. The hemodynamic changes during anesthesiaThere was no significant difference in SBP, DBP at To between the two group (P>0.05). The SBP and DBP of group N at T2, T3, T4, T5 were equal with those at To (P>0.05). The SBP and DBP of group E at T2, T3, T4, T5 was decreased significantly compared with those at To (P<0.05). The SBP and DBP of group E at T2, T3, T4, T5 were decreased significantly than those of group N (P<0.05). There was no significant difference in HR during anesthesia between the two group (P>0.05). The SpO2 of two groups was higher than 95%.4. The volume of fluid influsion during anesthesiaThe volume of fluid influsion during anesthesia in group E was more than that in group N (P<0.05)5. The dosage of ephedrineNo patients in group N were injected ephedrine, however,6 patients in group E were injected ephedrine. The difference of the two groups was statistically significant (P<0.05)6. The degree of sensory and motor nerve blockThe onset time of sensory and motor nerve blocking of group N was shorter than that of group E (P<0.05). The duration of sensory and motor nerve blocking of group N was longer than that of group E (P<0.05).7. The block efficacy during operationsTwenty-nine cases of group N had satisfactory the block efficacy.28 cases of group E had satisfactory the block efficacy. There was no significant difference in the block efficacy between the two group (P>0.05)8. The VAS grade at the first 1,4,8 hours after operationsThe VAS grade of the two group at the first 1 hours after operations is 0 (P>0.05)The VAS grade of group N at the first 4 hours after operations was 2 for one patient and 0 for the rest. The VAS grade of group E at the first 4 hours after operations was 2 for two patients,1 for one patient and 0 for the rest.The VAS grade of group N at the first 8 hours after operations was 4 for two patients,3 for three patients,2 for one patient and 0 for the rest. The VAS grade of group E at the first 8 hours after operations was 5 for three patient,6 for four patients, 3 for eight patients and 1 for the rest (P<0.05).9. The adverse reactions in intraoperative and the first 48 hours after the operationThere were no cases of nausea, vomiting, urine retention in group N. There were 3 cases of nausea, vomiting,12 cases of urine retention in group E. The adverse reactions in group E were more than those in group N (P<0.05)Conclusions:1. Ultrasound guidance technology can provides imaging basis for precise management of lumbar plexus-sciatic nerve block.2. Compared with continuous epidural anesthesia, ultrasound guided lumbar plexus-sciatic nerve combined blocking provides minimal interference on hymodynamics, exactly anesthetic effect, longer duration of analgesia and fewer adverse reactions. It is the ideal method of anesthesia in knee arithroscopic surgeries of the elderly patients.