Application Of Dexmedetomidine For Postoperative Analgesia In Patients With Cesarean Section

Objective: Postoperative pain can result in many negative effects on the body of cardiovascular system, respiratory system, endocrine system, immune system etc, even more induce a horrible memory, chronic pain, neuropathic pain, or spiritual system disorders, such as depression. Especaily for maternal, postoperative pain will effect on the nursing of newborn, communication between the Maternal and child,even affect lactation. So postoperative analgesia of obstetrics is particularly important. But in this process we must consider the pathophysiological changes of maternal, uterine contractions can reduce the amount of postpartum hemorrhage, we will also take care wheather analgesic drugs affect the newborn through the secretion of milk, so the postoperative analgesic of obstetric, modes,times and drugs are all important, the general principle is: to achieve the objective requirements, minimal side effects,cannot cause adverse effects on maternal uterine contraction, and also have the minimum influence of lactation and neonatal nursing; Dexmedetomidine( Dex) is a new type of highly selective α2AR agonists, combined with α2, α1 adrenoceptor ratio is 1600:1; and the affinity of α2AR is 8 times of clonidine[1]. Dexmedetomidine locates on the central nerve and peripheral nervous system and other organs and tissues of α2AR, have the effect of sedation, analgesia, anti-anxiety, inhibition of sympathetic nerve activity, other effects include Inhibition of salivary secretion and shivering, diuresis. In clinical anesthesia, Dexmedetomidine can induce sedation,analgesia,anti-anxiety and reduce anesthetic dosage, reduce the sympathetic excitement during the period of anesthesia and operation, has the the stability of hemodynamics. Mantz[2] showed 63 patients who used dexmedetomidine only, 90%of them can maintain satisfactory Ramsay sedation score. During the period of anesthesia and operation,stress reaction often induced by above, it can result in heart rate and blood pressure increased,while dexmedetomidine can effectively inhibit the sympathetic nervous, thus inhibiti the noradrenaline release from sympathetic nerve, improve the stability of perioperative fo blood flow mechanics, and prevent the myocardial ischemia effectively [3]. Esmaoglua [4]showed they used dexmedetomidine during cesarean section, dexmedetomidine can keep the safety and effectiveness for maternal.The subject selected patients with cesarean section, compared dexmedetomidine plus pentazocine or pentazocine only for postoperative intravenous analgesia in cesarean section, observe the analgesic effect and the occurrence of adverse reactions, to evaluate the safty and feasibility of dexmedetomidine in the special population of maternalMethods: 60 patients who accepted cesarean section,ASA I ~ II, body weight 65 ~ 90 kg, age 25 ~ 30 years old, fasting 8h, epidural anesthesia during the operation. Applicated the intravenous analgesia pump after operation, were divided into two groups, experimental groupand control group. Each group had 30 cases. The experimental group used dexmedetomidine 100ug+ pentazocine 90mg+ saline to 50 ml, dexmedetomidine dosing rate of 0.06ug·kg-1h-1, pentazocine delivery rate of 0.05 mg·kg-1h-1, control group of pentazocine 90mg+ saline to 50 ml, the same dosing rate in compared group.Record the basic vital signs of postoperative 2h, 4h, 8h, 24h: the mean arterial pressure(MAP), respiration(R), oxygen saturation(Sp O2), heart rate(HR), analgesia grading, Ramsay sedation score, lochia quantity, and side effect: respiratory depression, dizziness, nausea, vomiting, urinary retention. The measurement data with the mean standard deviation(s) said. Within group comparisons by paired t test, between group comparisons used repeated measures analysis of variance, count data in percentage(%) said, with t test, P <0.05 showed statistically significant differences.Results: The ASA grade, age, body weight were not statistically significant in two groups P>0.05; during PCIA all the patients showed stability basic vital signs:respiration, blood pressure, heart rate, Sp O2 were all in normal range, no statistical difference, P>0.05; analgesia grading: compared with control group, the experimental group after 2h, 4h the pain grade was significantly less than that of control at the same time, P <0.05. Within the group, the control group after 8h, 24 h pain grade significantly less than 2h, P <0.05; compare Ramsay sedation score: experimental group each comments were significantly less than that of the control group at the same time, P <0.05. Within group had no significant difference between the two groups, the comparison of P >0.05; the incidence of adverse reactions and lochia compared the difference was not statistically significant, P > 0.05.Conclusion: Cesarean section postoperative intravenous analgesia in spray based pentazocine on the composite application of dexmedetomidine hydrochloride, circulatory function in patients with stable, sedation, can effectively increase the analgesic effect, does not increase the incidence of adverse reactions. It can be safely and effectively used in cesarean section postoperative intravenous analgesia.