Postpartum hemorrhage is currently the leading cause of maternal death in China. The vast majority of maternal deaths caused by postpartum hemorrhage can be avoided or conditions can be created to avoid them, and the key lies in early diagnosis and proper management of the causes of postpartum hemorrhage and its high-risk factors.
The four major causes of postpartum hemorrhage are weak uterine contractions, birth canal injury, placental factors, and coagulation dysfunction; the four major causes can exist together or as a result of each other; each cause includes various etiologies and high-risk factors. All mothers are at risk for postpartum hemorrhage, but those with one or more high-risk factors are more likely to experience it. It is important to note that some mothers, such as those with hypertensive disorders of pregnancy, combined anemia, dehydration, or short stature, may develop severe pathophysiologic changes even if they do not meet the diagnostic criteria for postpartum hemorrhage.
Definition and diagnosis of postpartum hemorrhage
Postpartum hemorrhage is defined as bleeding ≥ 500 ml in vaginal delivery and ≥ 1,000 ml in cesarean delivery within 24 h after delivery of the fetus; severe postpartum hemorrhage is defined as bleeding ≥ 1,000 ml within 24 h after delivery of the fetus; refractory postpartum hemorrhage is defined as severe postpartum hemorrhage that cannot be stopped by conservative measures such as contractions, continuous uterine massage or pressure, and requires surgery, interventional treatment or even hysterectomy.
Prevention of postpartum hemorrhage
(I) Strengthen prenatal health care
Actively treat underlying diseases before delivery, fully understand the high-risk factors of postpartum hemorrhage, and high-risk pregnant women, especially those with aggressive placenta praevia and placental implantation, should be referred to hospitals with blood transfusion and resuscitation conditions before delivery.
(2) Active management of the third stage of labor
Active and correct management of the third stage of labor can effectively reduce the amount of postpartum hemorrhage and the risk of postpartum hemorrhage, and is routinely recommended (level I evidence).
Prophylactic use of contractions: it is the most important routinely recommended measure to prevent postpartum hemorrhage, and contractin is preferred. Application: After delivery of the fetus in head position with anterior shoulder, after delivery of the fetus in abnormal position with whole body, or after delivery of the last fetus in multiple pregnancies, 10 U of contractin should be added to 500 ml of fluid and injected intravenously at 100-150 ml/h or 10 U of contractin should be injected intramuscularly.
It has a long half-life (40-50 min), rapid onset of action (2 min), easy administration, and 100 μg single dose intravenous push can reduce the use of therapeutic constrictors, and its safety is similar to that of constrictors. If there is a lack of constrictors, ergometrine or misoprostol may also be used as an option.
Delayed clamping of the umbilical cord and controlled cord retraction: Recent research evidence suggests that clamping the umbilical cord 1-3 min after delivery is more beneficial to the fetus and should be routinely recommended, with immediate post-delivery clamping and cutting of the umbilical cord considered only when fetal asphyxia is suspected and timely delivery and resuscitation are required (level I evidence). Controlled pulling of the umbilical cord to facilitate delivery of the placenta is not necessary to prevent postpartum hemorrhage and should only be used selectively if the midwife is skilled in pulling and it is deemed necessary (Level I evidence).
3. Prophylactic uterine massage: After prophylactic use of contractions, prophylactic uterine massage is not recommended routinely to prevent postpartum hemorrhage (level I evidence). However, midwives should routinely palpate the uterine fundus postpartum for uterine contractions.
Postpartum hemorrhage should be monitored closely for contractions and changes in bleeding volume, and the woman should have her bladder emptied promptly.
Treatment of postpartum hemorrhage
I. General treatment
The general management should be carried out while looking for the cause of bleeding, including seeking help from experienced midwives, superior obstetricians and anesthesiologists, informing the blood bank and laboratory department to make preparations; establishing double intravenous channels, actively replenishing blood volume; carrying out respiratory management, keeping the airway unobstructed, giving oxygen if necessary; monitoring bleeding volume and vital signs, keeping urinary catheter and recording urine volume; cross-matching blood; carrying out basic laboratory tests ( Blood routine, coagulation function, liver and kidney function, etc.) and parallel dynamic monitoring.
II. Treatment of the causes of postpartum hemorrhage
Etiological treatment is the most fundamental treatment. Check the contractions, placenta, birth canal and coagulation function, and deal with the causes of bleeding actively.
(a) Treatment of weak uterine contraction
1.Uterine massage or compression method: transabdominal massage or transabdominal transvaginal joint pressure can be used, massage time to restore normal contraction of the uterus and can maintain the contraction state, should be used with the application of contraction agents.
2.Application of contraction agents.
(1) contraction agent: the first-line drug for the prevention and treatment of postpartum hemorrhage. The treatment of postpartum hemorrhage is as follows: 10 U of indocin is injected intra-muscularly or into the myometrium or cervix, and later 10-20 U is added into 500 ml of crystalloid for intravenous infusion, the rate of administration is adjusted according to the patient’s response, the conventional rate is 250 ml/h, about 80 mU/min. intravenous infusion can take effect immediately, but the half-life is short (1-6 min), so continuous intravenous infusion is needed. Estradiol is relatively safe, but high doses can cause hypertension, water toxicity and cardiovascular system side effects; rapid intravenous injection of undiluted estradiol can lead to hypotension, tachycardia and/or arrhythmias, and is contraindicated. Because of the receptor saturation phenomenon, the unrestricted increase in dosage is not effective, and side effects may occur, so the total 24-h dosage should be controlled within 60 U.
(2) Carbetocin: The same method of use as for prevention of postpartum hemorrhage after cesarean delivery.
(3) Carboprost aminotriol: It is a derivative of prostaglandin F2α (15-methyl PGF2α), which can cause coordinated and strong contraction of the whole uterus. It is administered as 250 μg by deep intramuscular injection or myometrial injection, with onset of action at 3 min and peak effect at 30 min, and can be maintained for 2 h. Repeat as necessary, up to a total of 2,000 μg.
It is contraindicated in patients with asthma, heart disease and glaucoma, and should be used with caution in patients with hypertension; temporary vomiting and diarrhea are common side effects.
(4) Misoprostol: It is a derivative of prostaglandin E. It can cause powerful contractions of the whole uterus, and can be used as a first-line drug for the treatment of postpartum hemorrhage due to weak uterine contractions in the absence of contraction hormone. However, misoprostol has a large number of side effects, nausea, vomiting, diarrhea, chills and elevated body temperature are common; it is used with caution in hypertension, active heart, liver and kidney disease and adrenocortical insufficiency, and is contraindicated in glaucoma, asthma and allergy.
(5) Other: contraction agents for postpartum hemorrhage include carboprost suppositories (administered rectally or vaginally, with occasional transient gastrointestinal reactions or facial flushing but will disappear quickly) and ergometrine.
3. Hemostatic drugs: If contraction agents fail to stop bleeding, or if bleeding may be associated with trauma, consider using hemostatic drugs. Tranexamic acid, which has antifibrinolytic effect, is recommended. 1 dose of 1.00 g intravenous drip or intravenous injection, ld dose is 0.75~2.00 g.
4.Surgical treatment: If the above treatment is not effective, the following surgical methods can be used according to the patient’s condition and the physician’s proficiency. If the coagulation function is abnormal, in addition to surgery, supplemental coagulation factors are required.
(1) Uterine cavity tamponade: there are two methods of official cavity water bladder compression and official cavity gauze tamponade, after vaginal delivery, water bladder compression is preferred, and water bladder or gauze tamponade can be used during cesarean section. The amount of bleeding, the height of the uterine fundus, and the changes of vital signs should be closely observed after the cavity stuffing, and the hemoglobin and coagulation function should be monitored dynamically to avoid the accumulation of blood in the cavity, and the water bladder or gauze strips should be removed after 24~48 h. Attention should be paid to the prevention of infection.
(2) Uterine compression suture: The most commonly used suture is the B-Lynch suture, which is suitable for patients with postpartum hemorrhage due to weak uterine contraction, placental factors and abnormal coagulation, where uterine massage and contraction agents are ineffective and hysterectomy is possible. Complications after B-Lynch suturing have been reported to be rare, but there is a risk of infection and tissue necrosis, and the indications for the procedure should be understood. In addition, there are various modified techniques of uterine suturing such as square suture.
(3) Pelvic vascular ligation: including uterine artery ligation and internal iliac artery ligation, uterine vascular ligation is suitable for refractory postpartum hemorrhage, especially hemorrhage due to weak uterine contraction or placental factors during cesarean section, which is ineffective by uterine contraction and massage of the uterus, or uterine incision tear and local hemostasis is difficult.
A 3-step vascular ligation method is recommended: bilateral superior uterine artery ligation; bilateral inferior uterine artery ligation; bilateral ovarian uterine vascular anastomosis branch ligation.
1. Internal iliac artery ligation is difficult to perform surgically and requires an obstetrician and gynecologist skilled in pelvic floor surgery to operate. It is indicated for bleeding from the cervix or pelvic floor, bleeding from the cervix or broad ligament, retroperitoneal hematoma, and postpartum bleeding for which conservative treatment is ineffective. The external iliac and femoral arteries need to be accurately identified before and after ligation, and care must be taken not to damage the internal iliac vein, as this can lead to severe pelvic floor bleeding.
(4) Transcatheter arterial embolization (TAE): This method is suitable for hospitals with conditions. Indications: Various kinds of refractory postpartum hemorrhage (including lack of uterine contraction, birth canal injury and placental factors, etc.) that have not been treated by conservative treatment, and stable maternal vital signs. Contraindications: Patients with unstable vital signs who should not be moved; DIC combined with bleeding from other organs; severe cardiac, hepatic, renal and coagulation dysfunction; allergy to contrast agents.
(5) Hysterectomy: Applicable to those for whom various conservative treatment methods are ineffective. It is usually a subtotal hysterectomy, or a total hysterectomy if placenta praevia or partial placenta implantation in the cervix. Operation precautions: Since there is still active bleeding during hysterectomy, it is necessary to “clamp, cut, and move down” as fast as possible until the clamp is below the level of uterine artery, then suture and tie the knot, paying attention to avoid damaging the ureter. For extensive post-hysterectomy pelvic oozing, use large gauze to compress and stop bleeding and actively correct coagulation dysfunction.
(B) Treatment of obstetric injuries
Fully expose the surgical field, identify the injury site under good illumination, pay attention to the presence of multiple injuries, pay attention to the restoration of anatomical structures when suturing, and start suturing at a point 0.5 cm beyond the top of the laceration, and apply intralesional anesthesia if necessary. If a hematoma is found, it can be treated as early as possible by incision to remove the accumulated blood, suturing to stop the bleeding or filling the hematoma with iodophor gauze to stop the bleeding by compression (removed after 24~48 h).
If the uterus is turned inside out, the mother is not in serious shock or bleeding, and the cervical ring is not yet tightened, the endometriotic uterine body can be returned immediately, and those who have difficulty in returning can be returned after anesthesia. After retraction, intravenous injection of uterine constrictor should be given until the hand is withdrawn after good contraction. If vaginal rejection fails, it can be changed to transabdominal uterine rejection. If the patient’s blood pressure is unstable, rejection can be performed at the same time as anti-shock.
2. Uterine rupture: immediately open the abdomen for surgical repair or perform hysterectomy.
Ligation of upper branches of bilateral uterine arteries; ligation of lower branches of bilateral uterine arteries; ligation of anastomotic branches of bilateral ovarian uterine vessels
(C) Management of placental factors
After the fetus is delivered, try to wait for the placenta to be delivered naturally.
1. Retained placenta with bleeding: for those who have not delivered the placenta with active bleeding, manual placental ablation can be performed immediately and strong official contraction agents can be added. For vaginal delivery, sedation can be used before the operation, the technique should be correct and gentle, do not forcibly tear and pull to prevent placenta residue, uterine injury or uterine inversion.
2, placenta residue: for placenta and fetal membrane residue should be cleaned up by hand or instrument, the action should be gentle to avoid uterine perforation.
3, placenta implantation: placenta implantation with active bleeding, if it is a cesarean delivery, conservative treatment methods can be used first, such as pelvic vascular ligation, local wedge resection of the uterus, interventional treatment, etc.; if it is a vaginal delivery, interventional treatment or other conservative surgical treatment should be performed under the premise of fluid and/or blood transfusion. If conservative treatment methods cannot effectively stop the bleeding, hysterectomy should be considered in time.
4.Vicious placenta praevia: that is, placenta praevia attached to the lower uterine segment at the caesarean section scar, often combined with placental implantation and heavy bleeding. It is listed separately here to attract attention. If conservative treatment measures such as local sutures or wedge resection, vascular ligation, compression sutures, and uterine artery embolization cannot effectively stop bleeding, early decision to remove the uterus should be made to avoid the development of hemorrhagic shock and multiorgan failure that endangers maternal life. For hospitals with conditions, prophylactic internal iliac artery balloon block can also be used to reduce intraoperative bleeding.
(iv) Management of coagulation dysfunction
Once coagulation dysfunction is diagnosed, especially DIC, the appropriate coagulation factors should be supplemented rapidly.
1. Platelet count: When postpartum bleeding is not yet controlled, if the platelet count is lower than (50~75)×l09/L
Or if the platelet count decreases and uncontrollable bleeding occurs, then platelet transfusion should be considered, and the therapeutic goal is to maintain the platelet count above 50×l09/L.
2.Fresh frozen plasma: Fresh anticoagulated whole blood is separated within 6~8h and frozen rapidly, which preserves almost all the coagulation factors, plasma proteins and fibrinogen in the blood. The application dose is 10~15 ml/kg.
3.Cold precipitation: The main purpose of cold precipitation infusion is to correct the lack of fibrinogen, if the fibrinogen level is higher than 1.5 g/L, cold precipitation infusion is not necessary. The common dose of cold precipitation is 0.10~0.15 U/kg.
4, fibrinogen: input fibrinogen lg can raise the blood fibrinogen 0.25 g/L, 1 time can input fibrinogen 4~6
g (the input dose can also be decided according to the patient’s specific situation).
In conclusion, the main goal of coagulation factor supplementation is to maintain both prothrombin time and activated prothrombin time <1.5 times the mean value and to maintain < span="">fibrinogen levels above 1 g/L.
III. Transfusion therapy for postpartum hemorrhage
Component transfusion plays a very important role in the treatment of postpartum hemorrhage, especially severe postpartum hemorrhage. The purpose of blood transfusion for postpartum hemorrhage is to increase the oxygen-carrying capacity of blood and replenish the lost coagulation factors. The indications for blood transfusion should be mastered in conjunction with the actual clinical situation, so as to achieve timely and reasonable blood transfusion, and also to minimize unnecessary blood transfusion and its related adverse consequences.
1, red blood cell suspension: postpartum hemorrhage when to transfuse red blood cells there is no uniform indications, is often based on the amount of maternal bleeding, clinical manifestations such as shock-related changes in vital signs, hemostasis and the risk of continued bleeding, hemoglobin levels and other comprehensive considerations to decide whether to transfuse.
In general, hemoglobin levels >100 g/L may not be considered for transfusion, while hemoglobin levels <60 g/L almost always require transfusion, and hemoglobin levels <7010="" 200="">80 g/L.
In addition, if the bleeding volume exceeds 1500 ml during cesarean section, hospitals that are in a position to do so may also consider filtering and transfusing autologous blood.
2. Coagulation factors: The methods of supplementing coagulation factors are the same as above, including the transfusion of fresh frozen plasma, platelets, cold precipitation, fibrinogen, etc. In addition, in cases where both drug and surgical treatment cannot effectively stop bleeding and the bleeding volume is large and there is coagulation dysfunction, hospitals with conditions can also consider using recombinant activated factor VII (rFⅦa) as an adjunctive treatment method, but it is not recommended for routine application due to insufficient evidence from clinical studies, and the applied dose is 90μg/kg, which can be repeatedly administered within 15~30 min.
3, hemostatic resuscitation and obstetric massive transfusion: hemostatic resuscitation (hemostatic resuscitation) emphasizes early and aggressive transfusion of plasma and platelets to correct coagulation abnormalities during massive transfusion of red blood cells (no need to wait for coagulation test results), while limiting early input of excessive fluids to expand volume (crystalloids not more than 2,000 ml. colloid fluids not more than 1,500 ml) and allowing resuscitation under Resuscitation under controlled low pressure conditions.
Premature infusion of large amounts of fluid can easily lead to a decrease in the concentration of coagulation factors and platelets in the blood, resulting in “dilutive coagulopathy” and even DIC and uncontrollable bleeding; excessive crystalloid fluid tends to accumulate in the third compartment, which may cause complications such as brain, heart and lung edema and abdominal septal compartment syndrome.
The role of obstetric massive transfusion in the management of severe postpartum hemorrhage is gaining more and more attention and application, but there is no unified obstetric massive transfusion protocol (MTP). According to the commonly recommended protocols at home and abroad, it is recommended that red cells:plasma:platelets be transfused in the ratio of 1:1:1 (e.g., 10 U red cell suspension + 1000 ml fresh frozen plasma + 1 U mechanically harvested platelets). If conditions allow, early application of rFⅦa can also be considered.
Process of postpartum hemorrhage management
The management of postpartum hemorrhage can be divided into the early warning period, the management period and the critical period, and the primary, secondary and tertiary emergency protocols can be activated respectively. If the bleeding volume reaches 400 ml 2h after delivery and the bleeding is not yet controlled, it is the early warning line, and the primary emergency treatment should be activated rapidly, including establishing two open intravenous channels, oxygenation, monitoring vital signs and urine output, seeking help from higher-level medical personnel, cross-matching blood, and actively searching for the cause of bleeding and dealing with it; if the bleeding continues, the corresponding secondary and tertiary emergency measures should be activated. Etiological treatment is the most important treatment for postpartum hemorrhage, and at the same time, anti-shock treatment should be given, and assistance from anesthesiologists, ICU and hematologists should be sought for resuscitation. Group collaboration is very important in resuscitating postpartum hemorrhage.
If conditions for resuscitation of severe postpartum hemorrhage are lacking, early and reasonable referral should be made. Referral conditions include.
(1) The woman’s vital signs are stable and can tolerate the referral;
(2) Adequate communication and coordination with the receiving unit before referral;
(3) the receiving unit has the relevant resuscitation conditions. However, for those who have had severe postpartum hemorrhage and are not suitable for referral, they should be resuscitated locally and can be referred to a higher level hospital.