| BACKGROUNDIn many kinds of operations such as labor analgesia, anesthesia for cesarean section, and nonobstetric surgery during pregnancy, correct selection of anesthetics and analgesia methods is very important for the safety and success of surgery. An optimal anesthetic should have an excellent property of analgesia without any side-effect to mother and neonate. However, the anaesthetics used in the procedure of anesthesia may influence the contraction of pregnant uterus, which may be harmful to mother and neonate. It can delay the progress of labor, incur abnormal uterus bleeding after labor, or induce abortion at the first trimeter of pregnancy. So, the study about the effect of anaesthetics on the contraction of uterine is essential, which is good for guiding the selection of anesthetics used in obstetric.Opioids are widely used in the field of obstetric analgesia and anesthesia. The addition of opioids to local anesthetics can improve the quality of analgesia and increase the duration of the block. It can also reduce the stress and keep hemodynamics stable during the operation when it is used in anesthesia for cesarean delivery and nonobstetric surgery during pregnancy, therefore it increases the safety of parturients and neonates. Fentanyl ,sufentanil and Remifentanil are the most widely used opioids in the obstetric analgesia and anesthesia field. Yoo's study showed that fentanyl and sufentanil had inhibitory effect on the force ofuterine contraction. However, few studies cover remifentanil, and little is known about the effect of opioids on the duration and frequency of uterine contraction. So it's valuable to study the above for providing reference to labor analgesia and anesthetic in obstetric clinic.Materials and methods:Healthy pregnant SD rats at 18-21 days gestation were classified into four groups at random, of which one was used as the control and the others was used as the trial. After getting the regular uterine contraction graph, which could be observed by Medlab biological information collection system, De Jalon's solution or opioids (remifentanil, sufentanil or fentanyl) was added into the bath (which was filled with De Jalon's solution) step by step every 15-20 minutes. The force, duration and frequency of contraction were monitored and registered so as to be analyzed later.Data analysis:All the data were presented as Mean ± SD and appropriate Analysis was performed with using the SPSS 11.0 for windows. Data were assessed for normal distribution of variance. Mean were assessed by one-way analysis of variance or t-test if normally distributed, or nonnormally distributed means were assessed by Mann-Whitney U test. Statistical significance was defined as P < 0.05.Resultsl.The isolated myometrial contraction force (g) of pregnant rats before adding fentanyl was 3.70+0.40, Contrasted with the isolated myometrial contraction force (g) of pregnant rats before adding fentanyl, the contraction force changed without statistic difference when fentanyl's concentrations^, that is mol/1) was 1 X 10"8M, 3 X 10"8M, 1X 10'7M, 3 X 10'7M or 1 X 10"6M. when fentanyl's concentrations were 3 X 10"6M and 1 X 10"5M.,the contraction force was 2.47+0.64 and 1.62 + 0.42, which was significantly reduced (t=5.29, P=0.00 and t=l 1.29, P=0.00).2.The myometrial contraction force of isolated pregnant rats before adding sufentanil was 3.67 + 0.32, Contrasted with the myometrial contraction force of isolated pregnant rats before adding sufentanil, the contraction force changed without statistic difference when sufentanyl's concentrations was 1X 10"8M, 3 X 10'8M, 1 X 10"7M, 3 X 10"7M, 1X lO^M or 3 X 10"6M. while, the contraction force became 2.89 + 0.58 when sufentanyl'sconcentrations were 1 X 10'5M, which reduced significantly (t=4.03,P=0.001). 3.The myometrial contraction force of isolated pregnant rats before adding remifentanil was 3.76 + 0.47, Contrasted with the isolated myometrial contraction force of pregnant rats before adding remifentanil, the contraction force changed without statistic difference whenQ Qremifentanil's concentrations varied in our study ,which was 1X10 M, 3X10'M, IX10"7M, 3 X 10"7M, 1 X 10-6M , 3 X 10"*M or 1 X 10"5M. (P>0.05).4.Contrasted with the control, when these three opioids' concentrations were not less than 3X 10'6M , the effect of different opioids of the same concentration on the contraction forcevaried significantly (P<0.01). The inhibition of fentanyl was more distinct than that ofsufentanil, while remifentanil had no obvious inhibition.5. Contrasted with the isolated myometrial contraction duration of pregnant rats before adding fentanyl/sufentanil/remifentanil or that of the control, the myometrial contraction duration changed without statistic difference when these three opioids' concentrations varied in our study ,which was 1 X 10"8M, 3 X 10'8M, 1 X 10"7M, 3 X 10'7M, 1X 10"6M , 3 X 10"6M or 1X 10'5M. (P>0.05)6 .Contrasted with the isolated myometrial contraction frequency of pregnant rats before adding fentanyl/sufentanil/remifentanil or that of the control, the myometrial contraction frequency changed without statistic difference when these three opioids' concentrations varied in our study .which was 1 X 10"8M, 3 X 10'8M, 1X 10"7M, 3 X 10"7M, 1X 10"6M , 3 X 10"6M or 1X 10"5M. (P>0.05)conclusions:1. Fentanyl and sufentanil may inhibit myometrial contraction when they reach a certain concentration. The inhibition mainly embodies in reducing the force of myometrial contraction, while it may influence little on the duration and frequency of myometrial contraction.2. Of these three opioids, fentanyl's inhibition to the myometrial contraction force is more distinct than that of sufentanil, however, remifentanil has little effect on it. |
PDF Full Text Request