Effects Of Pregnancy Associated With Diabetes On The Duration Of Subarachnoid Block With Ropivacaine In The Parturient

BackgroundDiabetes is a kind of serious and popular disease which threatens healthy life of humans and the incidence of diabetes increasing year by year.Due to the changes in the life style,the number of diabetic gravidas is increasing.Pregnancy complicating diabetes mellitus can be divided into gestational diabetes mellitus and pre-gestational diabetes mellitus,both of which can have a complex impact on the mother and baby leading to a significantly higher cesarean section rate than that of ordinary women.Cesarean section is an important method of surgical midwifery and neuraxial blockade is often used in patients undergoing cesarean section.However,having been suggested in previous reports,local anesthetics had been confirmed to be neurotoxic which might cause temporary or even permanent sensory and motor dysfunction.In recent years,the growing number of reports implies that neuraxial blockade causes delayed neurofunctional recovery and even neurologic complications,especially in obstetric anesthesia.Previously,in many clinical reports,compared with nondiabetic patients,diabetic patients were more sensitive to local anesthetics.Compared with non-diabetic patients,sensory and motor blockage duration were significantly prolonged in diabetic patients undergoing spinal anesthesia and peripheral nerve block.Moreover,a retrospective survey exhibited that the risk of severe postoperative neurologic dysftunction in diabetic patients undergoing neuraxial anesthesia or analgesia was much higher than common patients.Similarly,it has been reported that in diabetic animals,nerve blockage of local anesthetics on was significantly enhanced.The neurotoxicity mechanism of local anesthetics was complicated.What5 s more,previous studies had suggested that there were similarities among physiological changes during pregnancy,diabetic peripheral neuropathy and peripheral neurotoxicity of local anesthetics on the pathogenesis.As reported previously,pregnant women are more sensitive to local anesthetics.Together with the effect of high glucose enviroment and local anesthetics toxicity on nervous system,the pregnancy complicating diabetes mellitus may be more sensitive to local anesthetics than normal pregnancy.In order to verify this view,this study used prospective controlled method to make comparisons in the blockage of sensory and motor and the incidence of neurological complications of intrathecal ropivacaine between gravidas with diabetes mellitus and non-diabetic pregnancy,to evaluate the sensitivity and neurotoxicity of parturient with diabetes to ropivacaine and analyze the related factors and to provide references for clinical anesthesiologists in diabetic pregnancy.Methods75 parturients who were presenting for elective cesarean section were randomly divided into pregestational diabetes mellitus group(group P,n=15),gestational diabetes mellitus group(group G,n=30)and non-diabetic parturients group(group N,n=30).After entering the operating room,parturients were given spinal anesthesia spinal at the L3-4 interspace with 0.5%hyperbaric ropivacaine 3ml with left lateral decubitus position.To determine the level of sensory block by lOg monofilament and evaluate the motor block with modified Bromage score,once the drugs had been injected and patients lay flat,and repeated every 15 minutes after 100min until the S2 sensory level was obtained.To record the anesthesia and operation process and main outcome measures:the maximum blockage dermatome level,the time T6 sensory level was obtained,the onset time of sensory block and motor block and the duration of the motor block and sensory block.Moreover,to record adverse reactions during the surgery,the evaluation of parturient neurological function was carried out by 3 easy sensory testing before surgery and 6,12,24 hours after anesthesia.ResultsThere was no statistical difference of age,height,weight,ASA level,operation time,and the numbers of cesarean section among three groups.Compared with Group N,the onset time of motor block of Group P were significantly shortened(P<0.05).Compared with Group N and Group G,the time T6 sensory level was obtained of Group P were significantly shortened(P<0.001).Compared with Group N and Group G,the duration of sensory(P<0.001)and motor(P<0.001)block were significantly prolonged.While,compared with Group N,there was no statistical difference in the onset time and the duration of sensory and motor block of Group G.Through correlation analysis,the duration of sensory and motor block had a correlation to the diabetic duration,fasting plasma glucose,2 hours postprandial plasma glucose,and glycosylated hemoglobin(| r |≥0.4,P＜0.05).ConclusionsParturients with pregestational diabetes mellitus are more sensitive to 0.5%hyperbaric ropivacaine compared to non-diabetic parturients and parturients with gestational diabetes mellitus.The duration of subarachnoid block was correlated to the diabetic duration,fasting plasma glucose,2 hours postprandial plasma glucose and glycosylated hemoglobin,which mean the longer the diabetic duration,the higher the glycosylated hemoglobin,the greater the sensitivity of diabetic patients to local anesthetics might be and the more obvious the enhancement of the blockage might be.For both diabetes and non-diabetes patients,the block with intrathecal 0.5%hyperbaric ropivacaine might not cause enough nerve injury to present actual clinical symptoms.