Emergencies in obstetrics

1. OBSTETRIC EMERGENCIES
& ANAESTHESIA
DR. APARNA L
MODERATOR: DR. AMAR

2. OBSTETRIC HEMORRHAGE
Although no consensus exists on the definition of massive obstetric
hemorrhage, presence of either of the following has been described:
1. Sudden blood loss > 1500 ml (25% of blood volume),
2. Blood loss > 3000 ml in less than 3 hours (50% of blood volume)
3. Blood loss of 150 ml/minute in 20 minutes (>50% of blood volume)
4. Requirement of acute transfusion of > 4 units of packed red blood
cells.

3. HOW IS OBSTETRIC HEMORRHAGE
DIFFERENT?
1. Inadequate recognition of risk factors: Due to insufficient clinical
evaluation, leading to delayed identification of antenatal hemorrhage
risk factors.
2. Difficulty in estimating blood loss: Peripartum hemorrhage
complicates accurate blood loss estimation due to dilution by
amniotic fluid and concealed bleeding.
3. Delayed diagnosis: Early signs of shock are masked by pregnancy-
related physiological changes, leading to delays in intervention.
4. High uteroplacental blood flow: During term pregnancy, the
uteroplacental unit receives 12% of the cardiac output, equating to
700 ml/min. This high blood flow creates a potential source of rapid
bleeding

4. MECHANISMS OF HEMOSTASIS
1. Uterine contraction, stimulated by endogenous oxytocic substances released
after delivery, represents the primary mechanism for controlling blood loss
at parturition.
2. Uterine contraction  constricts the spiral arteries and placental veins
spanning the myometrium and supplying the placental bed.
3. Uterine tetany  shearing forces that cleave the placenta from the uterine
wall through the layer of the uterine decidua.
4. After disruption of vascular integrity, mechanisms of coagulation include
 platelet aggregation and plug formation,
 local vasoconstriction,
 clot polymerization, and
 fibrous tissue fortification of the clot.

5. ANTEPARTUM HEMORRHAGE
It is defined as hemorrhage that occurs after 24 weeks of gestation to
before delivery
CAUSES OF APH

6. PLACENTA PREVIA
• Placenta previa occurs when the placenta covers the cervix.
• If any portion of the placenta overlies the os  previa,
• Any placenta near the os  low-lying.
• RISK FACTORS: multiparity, advanced maternal age, smoking history,
male fetus, previous cesarean delivery or other uterine surgery, and
previous placenta previa

7. DIAGNOSIS
• Transvaginal ultrasonography is the “gold standard”
• Magnetic resonance imaging
• Classic clinical sign -> painless vaginal bleeding during the second or
third trimester.
• Digital or speculum examination should be avoided
• Lack of abdominal pain and/or absence of abnormal uterine tone helps
distinguish placenta previa from placental abruption

8. OBSTETRIC MANAGEMENT
• The fetus is at risk from two distinct pathophysiologic processes:
o Progressive or sudden placental separation that causes uteroplacental
insufficiency
o Preterm delivery and its sequelae.
• The first episode of bleeding characteristically stops spontaneously and
rarely causes maternal shock or fetal compromise.
• Expectant management in the hospital has been shown to prolong
pregnancy by an average of 4 weeks after the initial bleeding episode.
• Maternal vital signs & Fetal evaluation(NST, BPP, USG) are done frequently,
and the hemoglobin concentration is checked at regular intervals.

9. OBSTETRIC MANAGEMENT
• Hemorrhage may be prevented by limitations on physical activity and
avoidance of vaginal examinations
• Stable patients without bleeding in the previous 48 hours -> Outpatient
management
• Corticosteroid -> accelerate fetal lung maturity
• Tocolytics - Controversial

10. OBSTETRIC MANAGEMENT
Vaginal delivery vs Cesarean section ?
• Placental edge– to–internal os distance
• >1 cm - trial of labor
• <1 cm - abdominal delivery

11. ANESTHETIC MANAGEMENT
• Airway examination
• Intravascular volume assessment
• History of previous cesarean delivery or other procedures that create a
uterine scar
• Large bore iv line
• Volume resuscitation should be initiated using a balanced salt solution
• Hemoglobin concentration measurement
• Availability of cross-matched blood should be ensured

12. ANESTHETIC MANAGEMENT
• SCD may decrease the risk for VTE in patients on bed rest
• Blood administration sets, fluid warmers, and equipment for invasive
monitoring should be immediately available
• Neuraxial anesthesia -> patients without active bleeding or intravascular
volume deficit
• Epidural anesthesia -> more stable BP and lower transfusion rates
• CSE -> patients without active bleeding
• Patients who have placenta previa even without active preoperative
bleeding remain at risk for increased intraoperative blood loss

13. ANESTHETIC MANAGEMENT
GENERAL ANAESTHESIA:
• RSI -> preferred technique for bleeding patients
• The choice of intravenous induction agent depends on the degree of
cardiovascular instability - Propofol, Ketamine and etomidate
• MAINTANANCE: In patients with modest bleeding and no fetal
compromise -> 50% nitrous oxide in oxygen can be administered with a
low concentration of a volatile halogenated agent before delivery to
prevent maternal awareness
• The concentration of nitrous oxide or halogenated agent can be reduced
or omitted in cases of severe maternal hemorrhage or fetal compromise

14. ANESTHETIC MANAGEMENT
• Oxytocin should be administered by intravenous infusion immediately
after delivery
• If bleeding continues, it may be best to discontinue the volatile
halogenated agent completely after delivery and to substitute 70% nitrous
oxide and an intravenous opioid or ketamine
• If the placenta does not separate easily -> placenta accreta may exist ->
massive blood loss and the need for cesarean hysterectomy

15. PLACENTAL ABRUPTION
• Complete or partial separation of
the placenta from the decidua
basalis before delivery of the
fetus
• Maternal hemorrhage may be
revealed by vaginal bleeding or
may be concealed behind the
placenta
• Fetal compromise occurs
because of the loss of placental
surface area for maternal-fetal
exchange of oxygen and

16. PLACENTAL ABRUPTION

17. DIAGNOSIS
• Classic presentation -> vaginal bleeding, uterine tenderness, and
increased uterine activity
• Concealed abruption -> vaginal bleeding may be absent -> gross
underestimation of maternal hypovolemia
• May manifest as idiopathic preterm labor
• Patients may have a variety of nonreassuring FHR patterns (bradycardia,
late or variable decelerations, and loss of variability)
• The diagnosis of placental abruption is primarily clinical, but in a subset
of cases, ultrasonography may help confirm it

18. PATHOPHYSIOLOGY
• Placental tissue displays
tissue factor and other
procoagulant substances on
cell membrane-> when
bleeding at the decidual-
placental ->
thromboplastic substances
are released into the central
circulation -> consumptive
coagulopathy and DIC

19. COMPLICATIONS
• Complications -> hemorrhagic shock, coagulopathy, fetal compromise or
demise
• “Ischemic placental disease” may underlie chronic placental hypoxia,
leading to preeclampsia, fetal growth restriction, and abruption
• The major risks for the fetus are hypoxia and prematurity.
• Separation of all or part of the placenta reduces gas exchange surface
area and can lead to fetal death

20. OBSTETRIC MANAGEMENT
• Definitive treatment -> delivery of the infant and placenta, but the degree of
maternal and fetal compromise and estimated gestational age determine the
timing and route of delivery
• Fetus is at or near term and both maternal and fetal status are reassuring ->
vaginal delivery
• Patient is preterm, the extent of abruption is minimal, and the mother and
fetus show no signs of compromise -> hospitalized & the pregnancy allowed
to continue to optimize fetal maturation
• Corticosteroid to promote fetal lung maturity
• Mother develops hemodynamic instability or coagulopathy, or the fetal status
becomes non-reassuring -> urgent cesarean delivery

21. ANESTHETIC MANAGEMENT
• Large-bore intravenous catheter
• Assess hemoglobin, coagulation status
• Blood product preparation
• When gauging volume status, the clinician must remain aware of the
possibility of hemorrhage concealed behind the placenta
• Placement of a urethral catheter to monitor urine output may help the
physician assess adequacy of renal perfusion

22. ANESTHETIC MANAGEMENT
• Labor and vaginal delivery
• Neuraxial labor analgesia -> hypovolemia has been treated and
coagulation status is normal
• Sympathectomy in patients at risk for extension of abruption and further
hemorrhage
• Worsen hemorrhage-associated tachycardia and hypotension
• Cesarean delivery
• SA, CSE, EA -> stable patients in whom intravascular volume status is
adequate and coagulation studies are normal
• GA -> urgent cesarean delivery accompanied by unstable maternal status,
a non-reassuring FHR pattern, or both

23. ANESTHETIC MANAGEMENT
• Aggressive volume resuscitation is critical. In cases of severe hemorrhage,
insertion of an intra-arterial catheter may aid prompt recognition of
hypotension and allow for frequent blood sampling and assessment of
anemia and coagulation status
• Patients with abruption are at risk for postpartum hemorrhage from uterine
atony and coagulopathy; after delivery, oxytocin should be infused promptly
• Persistent uterine atony requires the administration of other uterotonic
drugs
• Red blood cells (RBCs) and coagulation factors should be replaced as
indicated by laboratory studies

24. UTERINE RUPTURE
• Uterine scar dehiscence ->
uterine wall defect that does not
result in excessive hemorrhage
or FHR abnormalities and does
not require emergency LSCS or
postpartum laparotomy
Uterine rupture
•Uterine wall defect with maternal
hemorrhage and/or fetal
compromise sufficient to require
emergency cesarean delivery or
postpartum laparotomy

25. DIAGNOSIS
• An FHR abnormality is the first sign of uterine rupture in more than 80% of
patients
• Triad -> abdominal pain, abnormal FHR pattern, and vaginal bleeding
• Other signs: vaginal bleeding, uterine hypertonia, cessation of labor,
maternal hypotension, loss of the fetal station, decrease in cervical dilation,
or a change in fetal presentation.
• Breakthrough pain and need for frequent re-dosing during neuraxial labor
analgesia may also indicate impending or evolving uterine rupture

26. DIAGNOSIS
OBSTETRIC MANAGEMENT
• Treatment options for uterine rupture include repair of the uterus, arterial
ligation, and hysterectomy
ANESTHETIC MANAGEMENT
• Patient evaluation and resuscitation are initiated while the patient is being
prepared for emergency laparotomy
• General anesthesia may be necessary, but surgery can proceed under
neuraxial anesthesia in stable patients with preexisting epidural labor
analgesia
• Aggressive volume replacement is essential, and transfusion may be
necessary
• Urine output should be monitored

27. POSTPARTUM HEMORRHAGE
• The American College of Obstetricians and Gynecologists (ACOG) defines
hemorrhage as blood loss greater than or equal to 1000 mL, or blood loss
accompanied by signs or symptoms of hypovolemia within 24 hours of birth
• Primary postpartum hemorrhage -> first 24 hours after delivery
• Secondary postpartum hemorrhage -> between 24 hours and 6 weeks after
delivery

28. POSTPARTUM HEMORRHAGE

29. UTERINE ATONY
• Postpartum hemostasis involves
the release of endogenous
uterotonic agents (oxytocin and
prostaglandins) -> contract the
uterus and constrict uterine
vessels
• Uterine atony represents a failure
of this process
• In addition, parturients with
obstetric hemorrhage may have
uterine arteries that are relatively
unresponsive to vasoconstrictor
substances.

30. DIAGNOSIS
• An atonic, poorly contractile uterus and vaginal bleeding are the most
common findings in patients with uterine atony
• The absence of vaginal bleeding does not exclude this disorder because the
atonic, engorged uterus may contain more than 1000 mL of blood
• Unrecognized bleeding may manifest initially as tachycardia; worsening
hypovolemia eventually leads to hypotension

31. OBSTETRIC AND ANESTHETIC
MANAGEMENT
• Prophylaxis: ACOG recommends active management of
third stage of labour -> uterine massage and prophylactic
oxytocin administration to decrease blood loss and
transfusion requirements compared with expectant
management

32. UTEROTONI
C AGENTS
Oxytocin (Pitocin)
•1st line agent
•SIDE EFFECTS:
vasodialation,
tachycardia,
hypotension, coronary
vasoconstriction,
myocardial ischemia,
seizures
•Administering a 5IU
bolus before infusion
does not provide any
higher benefits
•Carbetocin – longer
duration of action

33. UTEROTONIC AGENTS
Ergot Alkaloids: Methylergonovine (Methergin)
•2nd line agent
•Rapidly produce tetanic uterine contraction
•MOA- poorly understood, most likely mediated by
serotonergic agonism
•Associated with high incidence of PONV
•Relatively CI: hypertension, pre-eclampsia, PVD, IHD

34. UTEROTONIC AGENTS
Prostaglandins
•Increases myometrial calcium concentration leading
to increase in myosin light chain kinase activity
•15-methyl prostaglandin F2alpha (Carboprost) – may
cause bronchospasm, abnormal V/Q ratio, causing
hypoxemia
•Misoprostol – used for cervical ripening and induction
of labour
-has prolonged half life and can be given rectal or
sublingual

35. UTEROTONIC AGENTS

36. GENITAL TRAUMA
VAGINAL HEMATOMAS
•May involve bleeding from the descending branch of uterine artery
VULVAR HEMATOMAS
• Commonly involves pudendal artery

37. GENITAL TRAUMA
• RETROPERITONEAL HEMATOMAS
• Laceration of one of the branches of the hypogastric artery
• Occurs during cesarean delivery or rarely after rupture of a low transverse
uterine scar during labor
• The diagnosis of a retroperitoneal hematoma must be considered whenever a
postpartum patient has an unexpected decrease in hematocrit or unexplained
tachycardia and hypotension
• Other signs and symptoms are restlessness, lower abdominal pain, a tender
mass above the inguinal ligament that displaces a firm uterus to the
contralateral side, and vaginal bleeding with hypotension out of proportion to
the external blood loss
• Ileus, unilateral leg edema, urinary retention, and hematuria also may occur

38. ANESTHETIC MANAGEMENT
• Drainage of some vulvar hematomas -> Local infiltration and a small dose
of intravenous opioid
• Repair of extensive lacerations and drainage of vaginal hematomas require
significant levels of analgesia or anesthesia
• Spinal or epidural anesthesia may be necessary, although the clinician
should exercise caution initiating a neuraxial block in a hypovolemic patient
• Exploratory laparotomy for a retroperitoneal hematoma -> general
anesthesia.

39. RETAINED PLACENTA
• Retained placenta is defined as failure to deliver the placenta completely
within 30 minutes of delivery of the infant
• Retained placenta typically results from one of three causes:
• Placenta may be blocked behind a contracted lower uterus/cervix
(incarcerated placenta)
• Placenta may be adhered to the uterine wall (placenta adherens)
• May be invading the myometrium (placenta accreta)
• Risk factors : history of retained placenta, preterm delivery, oxytocin use
during labor, preeclampsia, and nulliparity

40. OBSTETRIC MANAGEMENT
• Gentle cord traction, uterine massage, manual removal, and inspection of
the placenta
• Manual extraction is not successful -> curettage
• Discontinue oxytocin during curettage and then, once the placenta has fully
delivered, restart it to augment uterine tone
• The eventual removal of the placenta typically promotes uterine contraction
and a reduction in bleeding.

41. ANESTHETIC MANAGEMENT
• Sedatives and analgesics -> examination and manual placental extraction
• Administration of local anesthetic through an indwelling epidural catheter
may prove helpful.
• Neuraxial anesthesia -> not bleeding severely and are hemodynamically
stable.
• General anesthesia -> hemodynamically unstable.
• Historically, RSI -> f/b high dose of a volatile halogenated agent to relax
the uterus
• Nitroglycerin -> uterine relaxation. rapid onset of reliable smooth muscle
relaxation and a short plasma half-life (2 to 3 minutes), produces uterine
smooth muscle relaxation by releasing nitric oxide

42. UTERINE INVERSION
• Uterine inversion, or the turning inside-out of all or part of the uterus, is a
rare but potentially disastrous event
• It is associated with severe postpartum hemorrhage, and hemodynamic
instability may be worsened by concurrent vagal reflex–mediated
bradycardia
• Risk factors : uterine atony, a short umbilical cord, uterine anomalies, and
overly aggressive management of the third stage of labor, including
inappropriate fundal pressure or excessive umbilical cord traction
• Uterotonic therapy can convert a partial inversion to a complete inversion

43. DIAGNOSIS
• Hemorrhage
• Mass in the vagina
• Ultrasonographic examination – echolucent zone with an echogenic mass in
the uterine cavity

44. OBSTETRIC MANAGEMENT
• Immediate replacement of the uterus, even before removal of the placenta
• All uterotonic drugs should be discontinued immediately
• The obstetrician should attempt to right the inversion by applying pressure
through the vagina to the uterine fundus; ring forceps may be used on the
cervix to apply countertraction
• Insertion of an intrauterine balloon may prove useful during treatment of
uterine inversion, preventing reinversion

45. ANESTHETIC MANAGEMENT
• Use of nitroglycerin to facilitate relaxation and replacement of the uterus
(200-250mcg IV)
• Support the circulation with intravenous fluids and vasopressors
• Administration of general anesthesia with a volatile halogenated agent may
become necessary, not only for uterine relaxation but also to prepare for
laparotomy should it become necessary to correct the inversion
• Once the uterus has been replaced, a firm, well-contracted uterus is desired
• Oxytocin should be infused, and additional uterotonic drugs may be needed

46. PLACENTA ACCRETA SPECTRUM
• Placenta accreta is defined as
a placenta that in whole or in
part invades the uterine wall
and is inseparable from it
• The combination of placenta
previa with previous cesarean
delivery synergistically
increases the risk for
coexisting placenta accreta,
particularly if the placenta is
anterior and overlies the
uterine scar

47. DIAGNOSIS
• In some cases of placenta accreta the condition is first suspected at vaginal
delivery, when the obstetrician notes difficulty in separating the placenta
from the uterine wall
• The definitive diagnosis is then made at laparotomy
• Antenatal diagnosis of placenta accreta facilitates effective planning
• USG/ MRI

48. OBSTETRIC MANAGEMENT
• The ACOG advises that clinicians working at small hospitals without
adequate blood bank supplies transfer patients with placenta accreta to a
tertiary care facility because there is a predictable need for massive
transfusion
• Most patients with known placenta accreta should undergo planned preterm
cesarean delivery and hysterectomy with the placenta left in situ because
attempts to remove the placenta are likely to initiate hemorrhage
• ? Preoperative insertion of internal iliac artery balloon catheters
• Prophylactic use of resuscitative endovascular balloon occlusion of the aorta
(REBOA) reduces blood loss during placenta accreta surgery

49. OBSTETRIC MANAGEMENT
• Conservative therapy:
• Small focal areas of placental invasion may be managed by curettage and
oversewing
• Leave the intact placenta in situ, close the uterus and abdomen, and await
spontaneous placental involution
• However, conservatively managed patients often require additional therapies
such as internal iliac artery balloon inflation, embolization, or methotrexate
• The ACOG considers planned peripartum hysterectomy to be the
management of choice for patients with placenta accreta and cautions the
obstetrician to reserve uterine conservation strategies for hemodynamically
stable patients who strongly desire future fertility

50. ANESTHETIC MANAGEMENT
• Anesthetic management is similar to other cases of severe postpartum
hemorrhage and peripartum hysterectomy
• Initial blood loss may be minimal but can rapidly become torrential if the
placental bed is disturbed or if the surgeons encounter unavoidable
placental tissue during the course of the hysterectomy

51. INVASIVE TREATMENT OPTIONS
• Intrauterine balloon tamponade
• Uterine compression sutures (e.g., B-Lynch suture)
• Angiographic arterial embolization
• Bilateral surgical ligation of the uterine arteries (O’Leary sutures)
• Peripartum hysterectomy
• Manual compression of the aorta

53. PERIPARTUM HYSTERECTOMY
• Definitive treatment for postpartum hemorrhage unresponsive to medical
and other invasive therapies
• Most common indications for this procedure are uterine atony and placenta
accreta
• Peripartum hysterectomy is a technically challenging operation; the uterus is
enlarged, exposure may be difficult, the vessels are engorged, and the
pregnant uterus receives a rich collateral blood supply
• Emergency peripartum hysterectomy is associated with increased blood
loss, worse coagulopathy, and increased transfusion rates compared with
planned peripartum hysterectomy

54. ANESTHESIA FOR PERIPARTUM
HYSTERECTOMY
• Frequently challenging because massive blood loss may occur unpredictably
• Maintenance of a T4 sensory level of anesthesia and judicious sedation may
reduce the need for intraoperative conversion to general anesthesia
• Single-shot spinal anesthesia is unlikely to provide anesthesia of sufficient
duration for an unanticipated hysterectomy
• Patients who have delivered vaginally with preexisting epidural labor
analgesia may be managed successfully with extension of epidural
blockade, but careful consideration of hemodynamic status should precede
the administration of local anesthetics into the epidural space

55. ANESTHESIA FOR PERIPARTUM
HYSTERECTOMY
• As the magnitude of blood loss increases -> GA anesthetic technique of
choice.
• severely hypotensive patients may require tracheal intubation for airway
protection
• large fluid shifts and massive transfusion may adversely affect oxygenation
so that control of ventilation via an endotracheal tube becomes necessary
• these same fluid shifts increase airway edema, potentially making failed
ventilation/failed tracheal intubation more likely as the surgery proceeds
• the massive transfusion of blood products often results in the need for co-
administration of potent vasopressors and calcium chloride

56. ANESTHESIA FOR PERIPARTUM
HYSTERECTOMY

57. TRANSFUSION THERAPY
•Considered in patients with Hb <7g/dL
•Active hemorrhage
BLOOD CONSERVATION STRATERGIES
•Treating IDA preoperatively
•Autologolus blood transfusion: preop donation,
normovolumic hemodilution, intraoperative blood
salvage
•Treatment of massive blood loss

58. TRANSFUSION THERAPY

59. SUMMARY
• Massive obstetric hemorrhage is defined as,
• loss of more than 1500 mL of blood
• drop in hemoglobin > 4 g/dL
• acute transfusion requirement of more than 4 units of blood.
• Communication is vital: Notify theater staff, alert the blood bank and
hematologist
• Joint assessment with the obstetrician and decision on further plan of action
• Continuous maternal and fetal monitoring

60. ANESTHETIC CONSIDERATIONS
• Profuse bleeding:
• Preop hypotension and fetal distress
• Requirement of large amount of blood
• Gross underestimation of blood loss if concealed hemorrhage
• Inadequate preoperative preparation due to emergency surgery
• Increased chances of postpartum hemorrhage.
• Possibility of extended surgery for:
• Emergency hysterectomy
• Uterine/internal iliac artery ligation.

61. OT PREPARATION
• Small-sized ETT
• Laryngoscope blade: Polio blade with short handle
• Airways, facemask, bougie, LMA, ETT, cricothyrotomy set
• Anesthetic drugs preloaded, emergency drugs, atropine, adrenaline
• Suction apparatus
• CVP and IBP transducer systems
• Fluid warmer, rapid fluid infusion devices, hand-inflated pressure bags
• Adequate amount of crystalloids and colloids
• Cross matched blood (atleast 2 units)

62. PATIENT PREPARATION
• Two large bore 14–16 G IV access
• Oxygen via face mask 6–8 L/min
• Arrange for fluids and cross matched blood ASAP
• CVP and IBP access for monitoring and fluid transfusion, Foley’s catheter
• Correct hypovolemia
• Correct coagulopathy
• Coagulation profile with TEG, Hb%, HCT, crossmatching
• Anti-aspiration prophylaxis
• SCD
• Double setup examination done with full preparation for Cesarean section if
placenta previa suspected

63. CHOICE OF ANESTHETIC TECHNIQUE
• Regional anesthesia preferred if:
• Mild-to-moderate abruption
• Minimal bleeding
• No hypovolemia
• No coagulopathy
• No uteroplacental insufficiency
• General anesthesia preferred if:
• Uncontrolled hemorrhage
• Coagulopathy
• Fetal distress
• Patient refusal

64. CHOICE OF ANESTHETIC TECHNIQUE
• MONITORS
• SpO2
• ECG
• NIBP
• ETCO2
• IBP, CVP
• Temperature
• Urine output
• CONTROL OF BLEEDING
• Uterotonic Therapy
• Medical Management –
Fibrinolytics, MTP
• Surgical Management

67. AMNIOTIC FLUID
EMBOLISM
• Incidence of 2-7 per 100000
deliveries
• Mortality rate of 0.5-6 per
100000 deliveries

68. DIAGNOSIS

69. DIFFERENTIALS

70. MANAGEMENT

72. REFERENCES
•Chestnut’s Obstetric Anaesthesia
•https://www.uptodate.com/contents/anesthesia-for-
the-patient-with-peripartum-
hemorrhage?source=history_widget
•https://www.apicareonline.com/index.php/APIC/article/
download/392/1247?inline=1
•M. Walfish, A. Neuman, D. Wlody, Maternal
haemorrhage, BJA: British Journal of Anaesthesia, Volume
103, Issue suppl_1, December 2009, Pages i47–
i56, https://doi.org/10.1093/bja/aep303

73. THANK YOU