petr krepelka, 2013. hemorrhage is the underlying causative factor in at least 25% of maternal...
TRANSCRIPT
Petr Krepelka, 2013
Hemorrhage is the underlying
causative factor in at least
25% of maternal deaths
in deveveloped and developing countries
CR 22,4%
SRB,B.,VELEBIL,P. Analysis of maternal mortality in Czech republic 2000. Česká gynekologie, 2002, 9, p.268-74.
PPH23%
DVT-PE20%
Cardiopathy16%
Others31%
Infections4%
Preeclampsia6%
Maternal physiology is well prepared for hemorrhage
• Increase in blood volume • Plasma• RBC
• Hypercoagulable state• Increase in plasmatic concentration of coagulating
factors
• The “tourniquet” effect of uterine contractions
Blood supply to the pelvis
• Internal iliac (hypogastric) arteries• Ovarian arteries
are the main vascular supply to the pelvis connected in a continuous arcade on the lateral borders of the vagina, uterus, and adnexa.
Blood supply to the pelvis
The ovarian arteries :• direct branches of the aorta beneath the renal
arteries. They traverse bilaterally and retroperitoneally to enter the infundibulopelvic ligaments.
Blood supply to the pelvis
The internal iliac arteries:• retroperitoneally posterior to the ureter
it divides into an anterior and posterior divisions.
The internal iliac arteries
Anterior division
3 parietal branches5 visceral branches
• Obturator
• Inferior gluteal
• Internal pudendal
• Uterine
• Superior vesical
• Middle rectal
• Inferior rectal
• Vaginal
The internal iliac arteries
Posterior division
Important collateral to the pelvis.• Iliolumbar• Lateral sacral• Superior gluteal
• Blood loss 24 hours after birth– >500 ml- vaginal delievery– >1000 ml - S.C.
–Bleeding • continues • repeats • destabilizes blood circulation or haemocoagulation
Definition of PPH
The causes of postpartum hemorrhage can be
thought of as the four Ts:
Etiology of PPH
Tone
Tissue
Trauma
Thrombin
Etiology of PPH
Uterine atony
Multiple gestation
High parity
Prolonged labor
Chorioamnionitis
Augmented labor
Tocolytic agents
Etiology of PPH
Retained uterine contents
Products of conception
Blood clots
Placental abnormalities
Congenital
Bicornuate uterus
Location
Placenta previa
Attachment
Accreta
Increta
Percreta
Acquired structural
Leiomyoma
Previous surgery
Peripartum
Uterine inversion Uterine rupture Placental abruption
Etiology of PPH
Lacerations and trauma
Planned
• Cesarean section
• Episiotomy
Unplanned
• Vaginal/cervical tear
• Surgical trauma
Etiology of PPH
Coagulation disorders
Etiology of PPH
Congenital
Von Willebrand's disease
Acquired
DIC
Dilutional coagulopathy
Heparin
Women in whom these factors have been identified should be advised to deliver in a specialist obstetric unit
odds ratio for PPH
Risk Factor
13
12
5
4
•Proven abruptio placentae
•Known placenta praevia
•Multiple pregnancy
•Pre-eclampsia/gestational hypertension
The following factors, becoming apparent labour are associated with an increased risk of PPH.
odds ratio for PPH
Risk factor
9455222
•Delivery by emergency Caesarean section •Delivery by elective Caesarean section •Retained placenta •Mediolateral episiotomy •Operative vaginal delivery •Prolonged labour (>12 hours) •Big baby (>4 kg)
Prophylactic oxytocics should be offered routinely in the management of the third stage of labour as they reduce the risk of PPH by about 60%.
The existence of some of the obstetric risk factors may be known early in pregnancy from and examination.
Antenatal assessment
history
Antenatal assessment
anemia
Detection of more than physiologic anemia of pregnancy is important, because anemia at delivery increases the likelihood of a woman requiring blood transfusion.
May be required in the presence of congenital or acquired coagulation defects
Antenatal assessment
Coagulation studies
… are useful in the detection of placental abnormalities, with
placenta previa and placenta accreta the most important identifiable risk
factors for massive hemorrhage
Antenatal assessment
Imaging investigations
Conventional gray-scale assessment has a sensitivity of 93%, a specificity of 79%, and a positive predictive value of 78% in the diagnosis of placenta accreta when previa and previous cesarean scar are present.
Antenatal assessment
Imaging investigations
Finberg HJ, Williams JW. Placenta accreta: prospective sonographic diagnosis in patients with placenta previa and prior cesarean section. J Ultrasound Med 1992;11:333-43.
Certain characteristics, such as the ”Swiss cheese appearance” with placenta previa, are associated with a threefold increase in mean blood loss during cesarean section.
Guy GP, Peisner DB, Timor-Tritsch IE. Ultrasonographic evaluation of uteroplacental blood flow patterns of abnormally located and adherent placenta. Am J Obstet Gynecol 1990;163:723-7.
Antenatal assessment
Imaging investigations
Colour Doppler may increase the specificity to 96%, which gives a positive predictive value in high-risk patients of 87% and a negative predictive value of 95% and allows better assessment of the depth of placental myometrial or serosal invasion.
Antenatal assessment
Imaging investigations
Chou MM, Ho ESC, Lee YH. Prenatal diagnosis of placenta previa accreta by transabdominal color Doppler ultrasound. Ultrasound Obstet Gynecol 2000;15:28-35.
Further imaging by MRI is recommended to assess bladder involvement in percreta and assess high-risk cases.
Thorp Jr. JM, Councell RB, Sandridge DA, et al. Antepartum diagnosis of placenta previa percreta by magnetic resonance imaging. Obstet Gynecol 1992;80:506-8.
Antenatal assessment
Imaging investigations
• loss of the hypoechogenic retroplacental zone• irregular uterine serosa• high vascularisation between myometrium and placenta• intraplacental lacunae• thinning of uterine wall
Guidelines by the Scottish Executive Committee of the RCOG
COMMUNICATE. RESUSCITATE. MONITOR / INVESTIGATE. STOP THE BLEEDING.
COMMUNICATEcall 6
• Call experienced midwife • Call experienced obstetrician • Call experienced anaesthesiologist • Alert haematologist • Alert Blood Transfusion Service • Call porters for delivery of specimens / blood
RESUSCITATE• IV access with 14 G cannula • Head down tilt • Oxygen by mask, 8 litres / min• Transfuse
• Crystalloid (eg Hartmann’s)
• Colloid (eg Hemacel)
• once 3.5 litres infused, GIVE ‘O NEG’ If no cross-matched blood available OR give uncross-matched own-group blood, as available
• Give up to 1 liter Fresh Frozen Plasma and 10 units cryoprecipitate if clinically indicated
MONITOR / INVESTIGATE
• Cross-match 6 units • Full blood count • Clotting screen • Continuous pulse / BP / • ECG • Foley catheter: urine output • CVP monitoring • Discuss transfer to ICU
STOP THE BLEEDING
• Exclude causes of bleeding other than uterine atony • Ensure bladder empty • Uterine compression • IV syntocinon 10 units • IV ergometrine 500 mg • Syntocinon infusion (30 units in 500 ml) • IM Carboprost (500 mg) • Surgery earlier rather than late • Hysterctomy early rather than later
If conservative measures fail to control haemorrhage, initiate surgical haemostasis
SOONER RATHER THAN LATER
I. Acute laparotomy, direct intramyometrial injection of Carboprost (Haemabate) 0.5mg
II. Bilateral ligation of uterine arteries III. Bilateral ligation of internal iliac
(hypogastric) arteriesIV. Hysterectomy
Resort to hysterectomy SOONER RATHER
THAN LATER
(especially in cases of placenta accreta or uterine rupture)
HYSTERECTOMY RATHER
SOONER THAN LATER
Uterine rupture
Placenta accreta
Whole blood frequently is used for rapid correction of volume loss because of its ready availability, but component therapy is ideal. A general practice has been to transfuse 1 unit of fresh-frozen plasma for every 3 to 4 units of red cells given to patients who are bleeding profusely
Genital tract lacerations
Genital trauma always must be eliminated first
if the uterus is firm.
• Explore the uterine cavity.• Inspect vagina and cervix for lacerations.• If the cavity is empty, massage and give
methylergometrine 0.2 mg, the dose can be repeated every 2 to 4 hours.
• Rectal 800mcg. Misoprostol is beneficial (unfortunately is not accesible)
Management of uterine atony
During the administration of uterotonic agents, bimanual compression may control hemorrhage. The physician places his or her fist in the vagina and presses on the anterior surface of the uterus while an abdominal hand placed above the fundus presses on the posterior wall. This while the Blood for transfusion made available.
Management of uterine atony
Retained placenta
Retained placental fragments are a leading cause of early and delayed postpartum hemorrhage. Treatment is manual removal, General anesthesia with any volatile agent (1.5–2 minimum alveolar concentration (MAC)) may be necessary for uterine relaxation
On rare occasions, a retained placenta is an undiagnosed placenta accreta, and massive bleeding may occur during attempted manual removal.
Placenta accreta • Placenta accreta is defined as an abnormal
implantation of the placenta in the uterine wall, of which there are three types:
(1) accreta vera, in which the placenta adheres to the myometrium without invasion into the muscle.
(2) increta, in which it invades into the myometrium.
(3) percreta, in which it invades the full thickness of the uterine wall and possibly other pelvic structures, most frequently the bladder.
In a patient with a previous cesarean section and a placenta previa:
Placenta accreta
Previous one has 14% risk of placenta accreta
Previous two has 24% risk of placenta accreta
Previous three has 44% risk of placenta accreta
Uterine rupture
Rupture of the uterus is described as complete or incomplete and should be differentiated from dehiscence of a cesarean section scar.
Uterine rupture
The reported incidence …
For all pregnancies is 0.05%
After one previous lower segment cesarean section 0.8%
After two previous lower segment cesarean section is 5%
All pregnancies following myomectomy may be complicated by uterine rupture.
Complete rupture describes a full-thickness defect of the uterine wall and serosa resulting in direct communication between the uterine cavity and the peritoneal cavity.
Uterine rupture
Incomplete rupture describes a defect of the uterine wall that is contained by the visceral peritoneum or broad ligament in patients with prior cesarean section.
Uterine rupture
Dehiscence describes partial separation of the scar with minimal bleeding, with the peritoneum and fetal membranes remaining intact.
Uterine rupture
The identification or suspicion of uterine rupture must be followed by an immediate and simultaneous response from the obstetric team.
Surgery should not be delayed owing to hypovolemic shock because it may not be easily reversible until the hemorrhage is controlled.
Management of Rupture Uterus
Upon entering the abdomen, aortic compression can be applied to decrease bleeding.
Oxytocin should be administered to effect uterine contraction to assist in vessel constriction and to decrease bleeding.
Hemostasis can then be achieved by ligation of the hypogastric artery, uterine artery, or ovarian arteries.
Management of Rupture Uterus
At this point, a decision must be made to perform hysterectomy or to repair the rupture site. In most cases, hysterectomy should be performed.
In selected cases, repair of the rupture can be attempted. When rupture occurs in the body of the uterus,
Bladder rupture must be ruled out by clearly mobilizing and inspecting the bladder to ensure that it is intact. This avoids injury on repair of the defect as well.
Management of Rupture Uterus
A lower segment lateral rupture can cause transection of the uterine vessels. The vessels can retract toward the pelvic side wall, and the site of bleeding must be isolated before placing clamps to avoid injury to the ureter and iliac vessels.
Typically, longitudinal tears, especially those in a lateral position, should be treated by hysterectomy, whereas low transverse tears may be repaired.
Management of Rupture Uterus
Step by step devascularisation Uterine Artery Ligation
Uterine artery ligation involves taking large purchases through the uterine wall to ligate the artery at the cervical isthmus above the bladder flap .
Internal iliac artery ligation
The internal iliac artery is exposed by ligating and cutting the round ligament and incising the pelvic sidewall peritoneum cephalad, parallel to the infundibulopelvic ligament The ureter should be visualized and left attached to the medial peritoneal reflection to prevent compromising its blood supply.
The hypogastric artery should be completely visualized. A blunt-tipped, right-angle clamp is gently placed around the hypogastric artery, 2.5 to 3.0 cm distal to the bifurcation of the common iliac artery. Passing the tips of the clamp from lateral to medial under the artery is crucial in preventing injuries to the underlying hypogastric vein .
Internal iliac artery ligation
B-Lynch suture
Abdominal pelvic pressure pack
Bleeding after hysterectomy
Intraarterial therapeutic embolisation
• The first application - 1979• Benefits
– Effectiveness 90%– Identification of the bleeding source– Distal vascular stop
• Disadvantage– Time factor– Technical and personal conditions
Odegaard,E.: Intractable postpartum haemorrhage treated with selective arterial embolization. Tidsskr Nor Laegeforen.2003,123,19,s.2715-6.
