Establishment Of The Postpartum Hemorrhage Model Of Cesarean Section In Macaca Fascicularis With Uterine Atony Induced By Medicine

Background:Postpartum hemorrhage(PPH)is the leading cause of maternal morbidity and mortality and accounting for 25% of the maternal death all around the world, and nearly half of this happened in developing countries. About 81.2% of the maternal death caused by postpartum hemorrhage happened in our country.The primary factors that cause the postpartum hemorrhage are as followed:①uterine atony;②placenta tissue;③g enital tract lacetations;④coagulopathy.To those foctors ,there are all kinds of theropies were established and have achieved some effects.For example: uterine massage,uterine packing,appilication of the uterotonic agents (oxytocin, prostaglandin analogs,ect.), uterine compression suture techniques (such as B-Lynch brace sutures,Cho multiple square suturing ,the Hayman suturing technique ),selective uterine arterial and iliac artery ligation or embolisation.Manual removal of the placenta for retained placenta tissue; Repairing the lacerations and clearing the haematoma;transfusion of pached cells,platelets and so on.The most commom cause of postpartum hemorrhage is uterine atony,which could result from any factors inhibits the contraction of uterine. Approximately 80% PPH contributed to uterine atony,which is also the primary reason for PPH in the cesarean delivery.Since from the 1990s,the cesarean section rate in our country has been rising due to the developing of the science technical and the improvement of the people's life. The cesarean section rate is about 40% in most cities,some even beyond 60%.Although the cesarean section took important role in the treatment of high risk factors of gestation( dystocia, fetal distress, macrosomia and so on.), to some extent raised the survival rate of maternal and fetal. While many women without high risk factors chose the cesarean section as their childbirth way due to the indication of ceasarean section was increased, meanwhile the complication----PPH was increased and Overall survival has not been improved.The inhibition of uterine bleeding mostly depends on the contraction of the uterine muscle with the blood sinus closed,which denote as physiological lagation.The blood sinus of uterine open up and the uterine resembles a soft bursiform when uterine atony occures, hemorrhea would show up.Moreover the operation of cesarean section is a trauma for the uterine muscle,which leading to the uterus to be a condition of acute blood loss before the uterine muscle contraction. Although treated with various managements for stimulating the contraction of uterus,some patients still need to perform the hysterectomy.The uterius is the most important reproductive organ for female.After remove the uterus, most of women in reproductive age would subject to psychological disorder and physiological barrier.The research indicated that the ovarian failure would occur 4 years earlier in the hysterectomy women than the spontaneous menopause women and about 34% women suffered from ovarian failure or climacteric symptom 2 years after operation.Moreover, some lipides leading arteriosclerotic,prostaglandin, thromboxane in the plasm would rise up and increase the incidence of coronary heart disease.Resently,most research about PPH still focus on the retrospective anaysis,but not the change of physiopathology of the body or establishment of the animal model of PPH or the cochrane about PPH.In order to explore the mechanism of the PPH and find better therapies,we chose the non-human primate------macaca fascicularis as our experimental animal,which similar as human in physiology and anatomic structure .The animal model of PPH in cesarean section with uterine atony would provide a good platform for researching PPH in the future.MethodsPart.ⅠExplore the basic physiology values about pregnant macaca fascicularis in later gestational periodAfter 12 hours fasting ,draw the venous blood of pregnant macaca fascicularis in later gestational period (N=15)and normal unpregnant macaca fascicularis with the same ages(N=10) to measure the values of blood physiological and biochemical.Part.ⅡEstablishment and evaluation of the postpartum hemorrhage model of cesarean section in macaca fascicularis with uterine atony induced by medicine.Inducing the regular uterine contraction of the pregnant macaca fascicularis by OT,the classic cesarean section was performed after inhibited the uterine contraction by tocolytic agent.Duing the time ,the BL-420 Data Acquisition & Analysis System recorded the MAP,CVP,EMG of the animal.Then collected the blood loss from the fetal deliveryed to two hours after, observed the shape of the uterus and cut a small myometrial strips for pathological examination before sutured the uterus.ResultsPart.ⅠThe basic physiology values about pregnant macaca fascicularis in later gestational period.There are significant difference in WBC,NEU%,LYM%,PT,APTT,Fgb,TP,Alb,BUN,CR,CHOL,Glu,Fe,LDK,HDBH between the pregnant macaca fascicularis in later gestational period and the normal non-pregnant macaca fascicularis in the same age(p<0.05), it seems that there are some changes in the other indexs(RBC,HGB,HCT,MCV,MCH,MCHC,PLT,ALT,AST,ALP,T. Bili,TG,P ),but there is no significant difference between two groups(p>0.05).Part.ⅡEstablishment and evaluation of the postpartum hemorrhage model of cesarean section in macaca fascicularis with uterine atony induced by medicine1 The regular uterine contraction of macaca fascicularis in later gestational period could be induced by OT.2 Ritodrine could inhibite the regular uterine contraction induced by OT.3 The blood loss volume(BLV) from the fetal deliveryed to two hours after the operation in treatment group was (134.34±60.16)ml,which accounting for blood volume(BV)(26.13±1.88)%,while the lost blood volume in control group with 5% glucose solution was (31.98±16.25)ml, accounting for blood volume(7.76±3.72)%.The were significant difference in blood loss volume between two groups (P =0.047),and significant difference could be found in BLV/BV between them(P =0.002).4 There were no significant difference change in HCT and HBG between two groups after cesarean section(p=0.098;p=0.410).5 Both MAP and CVP in both group showed decreasing trend.But the MAP droped to <50mmHg at time of 60 minutes in treatment group,while CVP didn't declined significantly. After the fluid resuscitation the blood pressure and respiratory rate return to stable.The haemodynamics of control group remain relative stable during the operation.6 The uterus showed atony and was soft like bursiform after cesarean section in treatment group,while contracted well and hard like a ball in control group.7 There were a amount of bleeding focus scattered in the uterine muscle and most of red blood cells deposited in the blood vessel in the treatment group,while this phenomenon was found in control group but the uterine muscle was hypertrophic, which denoted a typical morphous of gestation.Conclusion1 There was some difference of blood physiological and biochemical parameters between the pregnant macaca fascicularis in later gestational period and the normal non-pregnant macaca fascicularis at the same age.The change of blood physiological and biochemical parameters in pregnant macaca fascicularis was similar as the human being.2 The regular uterine contraction of macaca fascicularis in later gestational period could be induced by OT3 The regular uterine contraction induced by OT could be inhibited by tocolytic agent-----ritodrine,leading to uterine atony artificially.4 The macaca fascicularis with uterine atony would occur PPH during the cesarean section.5 The animal model of PPH after cesarean section was established successfully.