The Anesthesia Effect Of Spinal Anesthesia With Different Dosage And Time Of Position Change In Rectocele Patients

Background: In recent years，the operation for rectocele has gradually inereased. Andthese operations always need special operational posture, such as prone, jackknifeposition.Spinal Anesthesia is often taken in this operation. When the patient was turned intojackknife position from supine position after spinal Anesthesia, the hemodynamics may beinstable. Meanwhile, the sensory block levels may increase in the jackknife position, ifhyperbaric bupivacaine was used in spinal anesthesia.Nowadays, hyperbaric or isobaric of0.5%bupivacaine was injected in the sitting position and keep the position for a few minutesin these operations; Or hypobaric bupivacaine was directly injected in the prone position.Also, researches found that the block level should reach L1~T11in order to prevent therectum dragging pain in the operation on rectum.And different dosage of hyperbaric of0.5%bupivacaine was injected in the traditional position (lateral position) in this experiment, keepthe supine position with head-up tilt of10degrees for15or20minutes, and turn into thejackknife position, then observing the hemodynamic changes and clinical effects.Objective: The aim of this experiment is to observe the hemodynamic changes in thepatient with different dosage of local anesthetics and different time of position change. Toinvestigate if the sensory block level can increase after10or15minutes of spinal anesthesia,when the patient was placed into jackknife position. To choose the optimum dosage and timeof position change, so as to make sure the hemodynamic changes stable, anesthetic effectssatisfactory and patient safe.Methods：This experiment included60patients (all female, aged46.58±9.51yr, weight59.58±9.64kg, ASA I~II)，scheduled to undergo rectocele neoplasty operations. All thepatients will be preoperatively injected phenobarbitone0.1g and atropine0.5mg. Routinemonitoring such as blood pressure,pulse oxygen saturation and ECG should be included.Thespinal anesthesia will be operated in the left lateral position with head-up tilt of10degrees inthe L3~L4crevice.When the spinal fluid outflows, hyperbaric of0.5%bupivacaine will beinjected with the speed of0.2ml/second. Keep the supine position for a few minutes and thenturn into jackknife position with head-up tilt of10degrees until the end of operation. Theywere randomly divided into six groups, A1, A2, B1, B2, C1and C2. In group A1patients, thedosage is1.6ml(8mg) and position changing time is15min. In group A2patients,the dosageis1.6ml(8mg) and position changing time is20min.In group B1patients,the dosage is 1.8ml(9mg) and position changing time is15min.In group B2patients,the dosage is1.8ml(9mg) and position changing time is20min.In group C1patients,the dosage is2.0ml(10mg) and position changing time is15min.In group C2patients,the dosage is2.0ml(10mg) and position changing time is20min. Record the usage of atropine,ephedrine,dragging effects and anesthetic assistant drugs such as fentanyl during the operation. Measurethe sensory blocked levels intermittently and record the increase of blocked levels. Record theSBP, DBP and HR of the patients at different times, such as pre-anesthesia,3min,5min and10min after anesthesia,before the turn body over,instantly,3min and5min after turning bodyover, when use the anastomat and the end of operation.Results: There was no difference in the basic information such as the age, height, weight,fluid infusion and urine volume in different groups. The analgesia effects in the group withthe dosage1.8and2.0ml are better than dosage1.6ml, also with the less dragging effects inthe group with the dosage1.8and2.0ml. However, this difference was not statisticallysignificant. When the position changing time is15min, the block levels arise at differentdegree, and little increase is seen when position changing time is20min.Meanwhile, there ismore usage of atropine and ephedrine in groups with the dosage2.0ml than other groups.However, this difference also was not statistically significant.5and10min after spinalanesthesia, the SBP decreased significantly when comparing with pre-anesthesia SBP in allgroups. Also, the SBP at the time of instantly changing position is significantly increasedwhen comparing with before changing position in all groups.5min after changing position, theSBP decreased when comparing with instantly changing position in all groups except B2andC1group.Conclusions: The optimum position changing time is20min and the optimum dosage ofhyperbaric bupivacaine is9mg in spinal anesthesia on the rectocele patients with the jackknifeposition, while the block levels would arise when position changing time is15min.5and10min after spinal anesthesia, the SBP decreased significantly when comparing withpre-anesthesia. And, the SBP significantly increased at the time of instantly changing positionwhen comparing with before changing position.