Anesthesia for the patient with peripartum hemorrhage

INTRODUCTION — Peripartum hemorrhage is a major cause of maternal morbidity and mortality. Effective management requires a multidisciplinary, structured approach, with recognition that obstetric hemorrhage can rapidly become life threatening. This topic will discuss the anesthetic management of patients with peripartum hemorrhage or conditions that increase the risk of such hemorrhage.

Obstetric management of these patients and the approach to the management of postpartum hemorrhage (PPH) are discussed in detail separately.

●(See "Overview of postpartum hemorrhage".)

●(See "Postpartum hemorrhage: Medical and minimally invasive management".)

●(See "Postpartum hemorrhage: Management approaches requiring laparotomy".)

PREANESTHESIA EVALUATION — Antenatal anesthesia consultation should be arranged for patients at high risk of peripartum hemorrhage and those for whom blood product preparation or transfusion may be complicated. (See "Overview of postpartum hemorrhage", section on 'PPH risk assessment tools and risk-based preparation'.)

All obstetric patients should be evaluated for potential difficulty with airway management to create a plan for safe airway management in case general anesthesia is necessary. (See "Airway management for the pregnant patient", section on 'Planning the approach to airway management'.)

In addition to the usual medical and prenatal history, and anesthesia-directed physical examination, the following considerations should be addressed antenatally whenever time permits.

●Bleeding diathesis – Patients with known bleeding diatheses should be evaluated, usually in consultation with a hematologist, to create a strategy for peripartum management. (See "Approach to the adult with a suspected bleeding disorder" and "Preoperative assessment of bleeding risk" and "von Willebrand disease (VWD): Gynecologic and obstetric considerations", section on 'Obstetric considerations'.)

●Refusal of blood products – Women who refuse blood products benefit from an antenatal discussion that addresses specific blood components, products derived from human plasma, alternative therapies, and strategies for blood conservation. As part of the informed consent process, the patient should specify which blood components and products and which therapies (eg, blood salvage, hemodilution) are acceptable (table 1). (See "Approach to the patient who declines blood transfusion".)

Many patients who refuse blood products will accept transfusion of clotting factors and fluids that are not derived from human plasma. Lyophilized fibrinogen concentrate is derived from human plasma, but tranexamic acid (TXA) and recombinant factor VIIa are not (table 1).

●Red blood cell antibodies – Blood crossmatching may be difficult and prolonged for patients with alloantibodies or autoantibodies to red blood cells. The blood bank should be consulted regarding the significance of antibodies identified on the antenatal blood type and screen to plan the timing and necessity for peripartum blood product preparation. (See "Red blood cell (RBC) transfusion in individuals with serologic complexity".)

GENERAL CONCERNS — General concerns regarding anesthesia for peripartum hemorrhage include the following:

●Neuraxial anesthesia (ie, spinal, epidural, combined spinal-epidural [CSE]) is usually the preferred technique for instrumental and cesarean delivery. However, the sympathectomy that accompanies these techniques can lead to profound hypotension, especially if the block is established rapidly and if circulating blood volume is significantly decreased by peripartum hemorrhage. Patients who are or have been bleeding should be resuscitated with intravenous (IV) fluid and vasopressors prior to initiation of neuraxial anesthesia. For hemodynamically unstable patients, general anesthesia is preferred. Specifically, lightheadedness or orthostatic hypotension in the sitting position indicate the need for general anesthesia.

●Neuraxial anesthesia may be contraindicated in patients who develop a dilutional or consumptive coagulopathy as a result of hemorrhage, because of the risk of spinal epidural hematoma.

●Two large-bore IV catheters should be placed for anesthesia for patients with obstetric hemorrhage. The decision to place an intra-arterial catheter for blood pressure (BP) monitoring and blood sampling should be individualized.

●Induction of general anesthesia in severely hypovolemic patients can also result in profound hypotension and cardiac arrest [1]. Patients should be resuscitated with IV fluid and supported with vasopressors prior to and during induction of general anesthesia. Capable assistance (preferably another anesthesia clinician) should be present during induction for patients with obstetric hemorrhage to maintain uninterrupted IV volume resuscitation and vasopressor administration and to assist with airway management. (See 'Induction of anesthesia with postpartum hemorrhage' below.)

●Rapid sequence induction and intubation should be performed for general anesthesia. Anticipate difficulty with airway management. Alternative airway management devices (eg, videolaryngoscope, flexible intubating scope) should be available, as well as a plan for a surgical airway, if necessary. (See "Rapid sequence induction and intubation (RSII) for anesthesia" and "Airway management for the pregnant patient", section on 'Preparation for airway management'.)

●Optimal transfusion of blood products requires careful attention to hemodynamics, oxygen delivery, and hemostatic function. Goal-directed therapy is preferred over fixed-ratio resuscitation, but standard laboratory tests do not always provide sufficiently rapid results to guide therapy.

Increasingly, in obstetric hemorrhage, trauma-related hemorrhage, and other clinical situations, viscoelastic tests (ie, thromboelastography [TEG] and thromboelastometry [ROTEM]) are being used to assess coagulation and to guide hemostatic resuscitation. TEG and ROTEM are emerging as faster, cheaper, and more efficient than multiple standard coagulation blood tests and equally as effective [2]. Use of TEG and ROTEM in obstetric hemorrhage is discussed separately. (See "Postpartum hemorrhage: Medical and minimally invasive management", section on 'Viscoelastic testing'.)

ANTEPARTUM HEMORRHAGE — The most common causes for antepartum hemorrhage after 20 weeks gestation are placenta previa and placental abruption. Uterine rupture and bleeding from vasa previa are rare causes of antepartum hemorrhage.

Obstetric management is discussed separately. (See "Placenta previa: Management" and "Acute placental abruption: Management and long-term prognosis" and "Uterine rupture: After previous cesarean birth" and "Uterine rupture: Unscarred uterus" and "Velamentous umbilical cord insertion and vasa previa".)

The anesthetic goals include hemodynamic and hemostatic resuscitation and timely anesthesia to facilitate both delivery and surgical interventions to control the source of bleeding. Anesthetic concerns for specific etiologies of antepartum hemorrhage are discussed below. (See 'Placenta previa' below and 'Placental abruption' below and 'Uterine rupture' below and 'Vasa previa' below.)

Placenta previa — Most women who initially present with symptomatic placenta previa respond to supportive therapy and do not require immediate delivery. However, the frequency and severity of recurrent bleeding are unpredictable, and these patients are at risk for massive hemorrhage before, during, and after delivery. (See "Placenta previa: Management".)

●Choice of anesthetic technique – Patients with placenta previa will almost always be delivered by cesarean. For scheduled, nonurgent cesarean delivery, neuraxial anesthesia is the preferred approach; the choice of anesthetic technique should be based on patient factors. (See "Anesthesia for cesarean delivery", section on 'Choice of anesthetic technique'.)

Placenta previa is a risk factor for morbidly adherent placenta (ie, placenta accreta, increta, or percreta). Catheter-based neuraxial techniques (epidural or combined spinal-epidural [CSE]) may be preferred for cesarean delivery with placenta previa to allow extension of anesthesia for unexpected cesarean hysterectomy. Regardless, a plan should be in place for conversion to general anesthesia in the event of massive postpartum hemorrhage (PPH). (See 'Scheduled cesarean hysterectomy' below and 'Postpartum hemorrhage' below and "Placenta accreta spectrum: Clinical features, diagnosis, and potential consequences" and "Placenta accreta spectrum: Management".)

For patients who are actively bleeding or for emergent cesarean delivery, general anesthesia is usually preferred.

An epidural catheter may occasionally be placed even if delivery is not imminent to facilitate rapid initiation of neuraxial anesthesia and avoid general anesthesia (eg, for patients with predicted difficulty with airway management or severe obesity).

●Blood product preparation – An active blood bank sample should be maintained at all times for patients who are hospitalized with placenta previa awaiting delivery. In the United States, the blood type and screen will have to be repeated every three days [3]. We crossmatch at least two units of blood for cesarean delivery for these patients.

Placental abruption — Obstetric management of patients with abruption may include expectant management, vaginal delivery, or cesarean delivery, depending on maternal and fetal condition and the gestational age. (See "Acute placental abruption: Management and long-term prognosis".)

Therefore, labor analgesia or anesthesia for instrumental or cesarean delivery may be required. Anesthetic concerns specific to placental abruption include the following:

●Partial abruption can become complete abruption at any time and may require emergent cesarean delivery or instrumental vaginal delivery.

●Patients with abruption are at increased risk of disseminated intravascular coagulation [4]. (See "Acute placental abruption: Pathophysiology, clinical features, diagnosis, and consequences".)

A complete blood count and coagulation studies should be performed prior to neuraxial anesthesia procedures for patients with suspected abruption.

●Abruption is associated with preeclampsia, which has implications for both regional and general anesthesia. Anesthetic management of patients with preeclampsia is discussed separately. (See "Anesthesia for the patient with preeclampsia".)

●Patients with severe abruption are at increased risk for extravasation of blood into the myometrium, which can result in refractory postpartum uterine atony and the need for cesarean hysterectomy. (See "Acute placental abruption: Management and long-term prognosis", section on 'Couvelaire uterus' and 'Postpartum hemorrhage' below and 'Scheduled cesarean hysterectomy' below.)

Uterine rupture — Uterine rupture is a rare cause of antepartum, intrapartum, and postpartum hemorrhage. Most uterine ruptures in resource rich countries are associated with a trial of labor after cesarean delivery (TOLAC). In resource-limited countries, uterine rupture is often related to obstructed labor and lack of access to operative delivery. (See "Uterine rupture: After previous cesarean birth" and "Uterine rupture: Unscarred uterus".)

Standard epidural analgesia does not mask the signs or symptoms of uterine rupture, and the American College of Obstetricians and Gynecologists supports the use of neuraxial analgesia during TOLAC [5]. Breakthrough pain during a TOLAC should always prompt a careful evaluation of analgesic distribution and density, as well as maternal and fetal wellbeing. The most common clinical manifestation of uterine rupture is an abnormal fetal heart rate pattern.

Urgent or emergency cesarean delivery is usually indicated for uterine rupture. As long as maternal hemodynamics are stable, neuraxial anesthesia may be appropriate, especially if a labor epidural catheter is in place. In cases of acute fetal compromise or severe maternal hypovolemia, general anesthesia is usually preferred. (See 'General concerns' above.)

Hemorrhage may be primarily intra-abdominal and may be difficult to quantify and appreciate. Unexplained hypotension unresponsive to fluid administration or expected doses of vasopressors may suggest concealed hemorrhage, especially with neuraxial analgesia in effect.

Vasa previa — Vasa previa refers to umbilical blood vessels that cross the cervical os, with abnormal, membranous insertion into the placenta. The bleeding from vasa previa is fetal and occurs most commonly when membranes rupture. The fetus can exsanguinate within minutes. (See "Velamentous umbilical cord insertion and vasa previa", section on 'Vasa previa'.)

Vasa previa is often diagnosed antenatally, with cesarean delivery scheduled at 34 to 35 weeks of gestation. These patients are often hospitalized between 30 and 34 weeks of gestation and may require emergent cesarean delivery, usually with general anesthesia, if membranes rupture, labor starts, or if fetal heart rate abnormalities occur. Similar to patients with placenta previa, an epidural catheter may occasionally be placed even if delivery is not imminent to facilitate rapid initiation of neuraxial anesthesia and avoid general anesthesia (eg, for patients with predicted difficulty with airway management or severe obesity).

POSTPARTUM HEMORRHAGE — Postpartum hemorrhage (PPH) is an obstetric emergency and is the most common cause of maternal mortality worldwide. In many cases, mortality due to PPH is preventable with appropriate resources and management. (See "Overview of postpartum hemorrhage", section on 'Epidemiology'.)

Most patients with PPH require analgesia or anesthesia for surgical interventions and involvement of the anesthesia clinician for hemodynamic and physiologic support. Etiologies for PPH include uterine atony, retained placenta, obstetric trauma (eg, lacerations, tears, uterine rupture), uterine inversion, and placenta accreta. With massive hemorrhage, hysterectomy may be required regardless of the etiology. Patients with hemodynamic instability should be moved to the operating room as soon as practically possible to allow initiation and maintenance of definitive treatment.

Multidisciplinary care and coordination — Management of PPH requires a team-based, structured approach. The keys to management of PPH are recognition of excessive bleeding before it becomes life threatening, identification of the cause, and appropriate intervention. We suggest the use of a unit-standard, stage-based obstetric hemorrhage emergency management plan with checklists, as recommended by numerous obstetric and women's health organizations including the National Partnership for Maternal Safety, to ensure timely diagnosis and treatment at the earliest possible stage of PPH [6-8]. (See "Overview of postpartum hemorrhage".)

Standardized definitions that categorize the severity of PPH based on quantified blood loss, vital signs, and uterine tone may improve unit-wide communication and recognition of, and timely intervention for, women experiencing obstetric hemorrhage [7,8]. There is no national consensus on strict definitions for stages of obstetric hemorrhage. However, there is consensus that clinicians should create common terminology at the institutional level and that care providers should communicate and manage hemorrhage in terms of stages. An example of a stage-based approach to PPH, with criteria that define each stage, is shown in a table and is described here (table 2).

Stage 0 begins with delivery of the neonate and refers to normal postpartum bleeding. Stage 1 reflects the initial signs of abnormal uterine bleeding following delivery and should trigger initial bedside interventions (eg, fluids, laceration repair, secondary uterotonics, manual removal of placenta) to establish a diagnosis and treat bleeding. Stage 2 is declared when bleeding continues or the patient continues to have unstable vital signs, despite initial interventions to control it. Stage 2 should trigger escalation of care. Stage 3 represents severe hemorrhage (>1500 mL cumulative blood loss) or coagulopathy, and stage 4 is defined as cardiovascular collapse with massive hemorrhage.

The anesthesiologist should be involved in all aspects of care at or beyond stage 1 hemorrhage. The components of evaluation and treatment are discussed in detail separately (table 3). (See "Postpartum hemorrhage: Medical and minimally invasive management" and "Postpartum hemorrhage: Management approaches requiring laparotomy" and "Overview of postpartum hemorrhage", section on 'Early recognition, assessment, and intervention'.)

Examples of multidisciplinary checklists, and interventions for management of PPH after vaginal and cesarean delivery are shown in an algorithm and tables (algorithm 1 and table 3 and table 4).

The Maternal Early Warning Criteria (MEWC) are associated with maternal morbidity and mortality and can be used to reduce the response time to PPH events and escalate care for at risk patients [9,10]. (See "Severe maternal morbidity", section on 'Prevention'.)

Anesthesia for postpartum hemorrhage — Options for anesthetic management for the procedures required to treat PPH depend on the type of delivery (ie, vaginal or cesarean), the required surgical procedure, the severity of hemorrhage, and the patient's hemodynamic status. For repair of cervical or vaginal lacerations, a short-acting sedative with or without local anesthesia may be adequate. Neuraxial or general anesthesia is usually required for more extensive repairs, intrauterine manipulation, removal of retained placenta, and open procedures.

Two large-bore intravenous (IV) catheters should be placed for all patients with PPH. The decision to place an intra-arterial catheter for blood pressure (BP) monitoring and blood sampling should be individualized.

Neuraxial anesthesia for postpartum hemorrhage — Neuraxial anesthesia (ie, epidural or spinal) may be appropriate for patients who are hemodynamically stable and without evidence of coagulopathy. For repair of cervical or vaginal lacerations, a T10 spinal level is adequate, while a T4 block is required for uterine manipulation or open surgical procedures. Neuraxial anesthesia produces a sympathectomy and vasodilation and can cause severe hypotension or hemodynamic collapse in patients with clinically significant hypovolemia.

●Epidural anesthesia – Labor epidural analgesia with a dilute concentration of epidural drug solution is often inadequate for surgical manipulation. A labor epidural catheter may be used to achieve a surgical level of anesthesia by injection of more concentrated local anesthetic (eg, lidocaine 2%) for vaginal or cervical repair. (See "Neuraxial analgesia for labor and delivery (including instrumental delivery)", section on 'Analgesia for instrumental vaginal delivery'.)

An existing epidural anesthetic may be extended for treatment of PPH after cesarean delivery. General anesthesia may be required if massive hemorrhage occurs or if epidural anesthesia is inadequate for extensive pelvic procedures. (See 'General anesthesia' below.)

The epidural catheter should only be removed when coagulation is confirmed to be normal after PPH.

●Spinal anesthesia – Spinal anesthesia may be appropriate for patients without a labor epidural catheter in place, if bleeding is modest and the patient is hemodynamically stable (eg, for retrieval of retained placenta). If an epidural catheter was in place and has been removed (either because the patient is postpartum or because the epidural catheter failed to provide effective anesthesia or analgesia), residual neuraxial blockade may be present. In such cases, full-dose spinal anesthesia should be performed with caution, because a high spinal anesthetic may result. (See "Anesthesia for cesarean delivery", section on 'Failed or inadequate neuraxial block'.)

●Combined spinal epidural anesthesia – A combined spinal epidural anesthetic can be performed, using a low-dose spinal, with the expectation that the epidural catheter may be used to extend the neuraxial blockade as needed. By limiting the spinal anesthetic dose, this technique reduces the risk of excessive neuraxial blockade and hemodynamic instability. (See "Epidural and combined spinal-epidural anesthesia: Techniques", section on 'Dose of spinal drugs'.)

Moderate sedation/analgesia for postpartum hemorrhage — Obstetricians often request sedation/analgesia if it is likely that bleeding will be easily controlled. The goal in this setting should be a level of sedation/analgesia no deeper than moderate sedation, which means that the patient responds purposefully to verbal commands, either alone or accompanied by light tactile stimulation, and maintains and protects her airway without support. Neuraxial and general anesthesia are more effective for controlling movement, so it is important to verify operative goals to ensure that movement (eg, leg adduction) would be acceptable during any procedure completed under sedation. (See "Monitored anesthesia care in adults", section on 'Monitoring depth of sedation and analgesia'.)

Sedatives and analgesics should be administered in small incremental doses (eg, midazolam 0.5 to 1 mg IV, fentanyl 50 to 100 mcg IV), titrated to effect, to avoid deep sedation and compromised airway reflexes. Moderate sedation/analgesia does not provide complete analgesia but helps patients tolerate brief painful procedures and may prevent recall of discomfort.

Ketamine (0.25 to 0.5 mg/kg IV) is often administered for sedation in this setting because it provides sedation, analgesia, and amnesia with minimal respiratory depression. We administer midazolam (0.5 to 1 mg IV) along with ketamine to reduce the risk of vivid dreams or hallucinations that can occur with ketamine. (See "Monitored anesthesia care in adults", section on 'Ketamine'.)

If conversion to general anesthesia becomes necessary, the patient should be moved to the operating room if not already there. She should be optimally positioned for endotracheal intubation prior to induction of anesthesia. This may require taking her feet out of stirrups and moving the patient to the top of the operating table. (See "Airway management for the pregnant patient", section on 'Patient positioning'.)

Uterine relaxation — Nitroglycerin (50 to 200 mcg IV repeated every two minutes, or 400 mcg sublingual) may be administered for rapid, brief uterine relaxation, usually along with moderate sedation, to facilitate removal of retained placenta or for replacement of an inverted uterus [11-13]. IV fluid and vasopressors are required to prevent hypotension when nitroglycerin is administered in this setting.

General anesthesia with 1 to 3 minimum alveolar concentration (MAC) of a potent inhalation agent (ie, sevoflurane, isoflurane, or desflurane) may be required to relax the uterus if nitroglycerin is not effective.

Tranexamic acid — We agree with national guidelines that recommend administration of tranexamic acid (TXA; 1 g IV over 10 to 20 minutes) (table 4), along with oxytocin and other uterotonics for women with PPH diagnosed within three hours of delivery. This recommendation is based on the results of the World Maternal Antifibrinolytic Randomized Trial (WOMAN), an international, randomized, placebo-controlled trial that reported decreased death due to bleeding in patients who received TXA, without an increase in adverse events including thromboembolism [14].

We administer an initial dose of TXA for patients with severe and ongoing bleeding. Further doses can be guided by coagulation testing (including thromboelastography [TEG] or rotational thromboelastography [ROTEM]), if available.

The use of TXA for PPH and the WOMAN trial are discussed in detail separately. (See "Postpartum hemorrhage: Medical and minimally invasive management", section on 'Administer tranexamic acid'.)

Resuscitative endovascular balloon occlusion of the aorta — In desperate situations, particularly in low-resource environments without interventional radiology and blood banking, or in patients with hemorrhage who refuse blood transfusion, resuscitative endovascular balloon occlusion of the aorta (REBOA) may offer a minimally invasive approach to resuscitation and allow time for definitive treatment. REBOA requires close coordination between the surgeon or interventionalist and the anesthesiologist, particularly prior to and during balloon deflation, to ensure adequate IV volume loading and administration of vasopressors. The use of REBOA is discussed separately. (See "Endovascular methods for aortic control in trauma", section on 'REBOA technique' and "Postpartum hemorrhage: Medical and minimally invasive management", section on 'Consider resuscitative endovascular balloon occlusion of the aorta'.)

General anesthesia for PPH — General anesthesia is the preferred anesthetic technique if postpartum hemorrhage (PPH) is severe or likely to become severe. General anesthesia may also be appropriate if moderate sedation/analgesia provides inadequate pain control in situations in which neuraxial anesthesia cannot be performed.

Advantages of general anesthesia for patients with severe PPH include the following:

●Secure airway – General anesthesia with endotracheal intubation provides a protected airway for severely hypotensive patients who may lose airway reflexes and a means for controlled ventilation should airway edema or pulmonary edema occur with IV fluid resuscitation.

●Muscle relaxation – General anesthesia allows administration of neuromuscular blocking agents (NMBAs) to relax abdominal and pelvic muscles to facilitate surgery.

●Vascular access – Large-bore IV catheters, arterial catheters, and central venous catheters (CVCs) are more easily placed in patients under general anesthesia rather than awake.

●Unconsciousness – General anesthesia allows the clinical team to focus on the patient's physical wellbeing. With an unconscious patient, clinicians can use direct, explicit, and unambiguous communication without concern for the awake patient's interpretation. This may facilitate accurate situational awareness and expeditious escalation in care.

Induction of anesthesia with postpartum hemorrhage — Induction of general anesthesia should not be delayed once the need for it is identified, because ongoing IV fluid resuscitation can cause airway edema and difficulty with endotracheal intubation. Induction of anesthesia can cause cardiovascular collapse in severely hypovolemic patients. Therefore, capable assistance (preferably another anesthesia clinician) should be present during induction for patients with PPH to maintain uninterrupted IV volume resuscitation and vasopressor administration and to assist with airway management. We administer etomidate (20 mg IV) or ketamine (0.5 to 1 mg/kg IV) rather than propofol for induction in hypovolemic patients to minimize the risk of hypotension. Airway edema and difficult airway management should be expected. (See 'General concerns' above.)

Maintenance of anesthesia for postpartum hemorrhage — Volatile inhalation anesthetics produce dose-dependent uterine relaxation [15], which can contribute to uterine atony and hemorrhage. We administer midazolam 2 mg IV, and nitrous oxide (N₂O) 50 to 70% to allow a reduced dose of volatile anesthetic to 0.5 to 0.75 MAC while preventing awareness under anesthesia.

Postoperative care after PPH — Patients with severe postpartum hemorrhage (PPH) may require postpartum intensive care for ongoing volume, hemostatic, and metabolic resuscitation and to monitor for recurrence or complications of PPH. (See "Overview of postpartum hemorrhage", section on 'Outcome'.)

For patients in whom a uterine pack or balloon is left in place after PPH, the plan for analgesia, and for anesthesia for potential emergent surgery or embolization, should be discussed with the obstetrician.

Delayed extubation, or extubation over an airway exchange catheter, should be considered for any patient who has had general anesthesia and received massive volume resuscitation, because of potential airway edema and obstruction after extubation. (See "Management of the difficult airway for general anesthesia in adults", section on 'Extubation'.)

SCHEDULED CESAREAN HYSTERECTOMY — Cesarean hysterectomy may be scheduled electively or semielectively and is most often performed after the antenatal diagnosis of a morbidly adherent placenta (ie, placenta accreta, percreta, or increta). These disorders of placentation may cause massive hemorrhage and are usually diagnosed based on risk factors and antepartum imaging. Unless otherwise noted, the following discussion of placenta accreta applies to all depths of placental invasion. (See "Placenta accreta spectrum: Clinical features, diagnosis, and potential consequences".)

Patients with placenta accreta are optimally managed by a multidisciplinary care team in a tertiary care facility. Antenatal anesthesia consultation should be part of multidisciplinary planning. (See "Placenta accreta spectrum: Management", section on 'Components of preoperative planning'.)

Placenta accreta may rarely be diagnosed when the surgeon enters the peritoneal cavity at the time of cesarean delivery. In such cases, the surgeon may choose to delay delivery while appropriate personnel and other resources are obtained or even to close the abdomen and transfer the patient to another facility. Subsequent anesthetic management will depend on the surgical plan and whether the existing anesthetic can be extended (ie, catheter-based neuraxial anesthesia versus single-shot technique). (See "Placenta accreta spectrum: Management", section on 'Unexpected placenta accreta'.)

Placenta accreta may also be diagnosed when massive, unexpected hemorrhage occurs after a vaginal delivery. Management of anesthesia for those patients is discussed above. (See 'Postpartum hemorrhage' above.)

Preparation for transfusion — Massive hemorrhage is always a possibility during planned cesarean hysterectomy, and the magnitude of blood loss is difficult to predict antepartum. Studies have reported median estimated blood loss of 2.5 to 7.8 liters [16-18]. Management of hemorrhage during cesarean hysterectomy should follow the same principles as for other causes of postpartum hemorrhage (PPH). (See 'Multidisciplinary care and coordination' above.)

●Blood product preparation – Institutional protocols for massive transfusion for trauma, or specific for obstetrics in high-volume facilities, can usually be applied in this setting, with the first "trauma pack" of blood products prepared (eg, 4 units of erythrocytes, 4 units of fresh frozen plasma, one pack of 5-donor unit platelets) and delivered to the operating room in advance. In some institutions, the obstetric trauma pack also includes 1 or 2 cryoprecipitate pools [each pool is composed of 5 individual units]) or lyophilized fibrinogen concentrate. The quantity of blood products that should be prepared in advance depends on the institutional capacity to rapidly deliver additional blood products and any patient-specific difficulty with crossmatch (eg, red blood cell antibodies) [19].

●Cell salvage – Intraoperative cell salvage may be used during cesarean delivery and is acceptable to some patients who refuse blood transfusion. (See "Surgical blood conservation: Intraoperative blood salvage".)

●Acute normovolemic hemodilution – Acute normovolemic hemodilution may be considered for patients with hemoglobin ≥11 g/dL and may also be acceptable to patients who refuse blood products. Antepartum administration of erythropoietin and iron may optimize hemoglobin in preparation for this technique [20]. (See "Surgical blood conservation: Acute normovolemic hemodilution".)

Venous access — At least two large-bore intravenous (IV) catheters should be placed. We usually place either an 8 French double-lumen central venous catheter (CVC) plus one large-bore peripheral venous catheter or a peripherally inserted central catheter plus two large-bore peripheral venous catheters, including ideally one 7 French rapid infusion catheter.

CVCs may be placed for venous access and/or for administration of potent vasopressors and calcium chloride in the event of a massive transfusion. Central venous pressure is of limited value for assessing volume status in this clinical context.

Monitoring — We frequently place an intra-arterial catheter prior to the start of cesarean delivery when placenta accreta is suspected to allow continuous blood pressure (BP) monitoring and to facilitate frequent blood sampling.

Choice of anesthetic technique — Neuraxial anesthesia, general anesthesia, or a combination of the two may be used for these procedures.

●Neuraxial anesthesia – A neuraxial catheter-based technique (ie, epidural anesthesia or combined spinal-epidural anesthesia [CSE]) may be appropriate when the risk of massive blood loss is expected to be low based on diagnostic imaging, the experience of the surgical team, and the specific surgical plan [21-26].

Increasingly, catheter based neuraxial anesthesia techniques are used in centers with experience with these cases and a multidisciplinary coordinated plan for management [27].

•In one review, 23 cesarean deliveries occurred between 2000 and 2008 at a center with a protocol for attempting uterine conservation for patients with antenatally diagnosed placenta accreta [21]. Uterine artery balloon catheters were placed preoperatively, and inflated as necessary for temporary control of bleeding. Over the study period, with increasing experience using the balloon catheters to provide hemodynamic stability, neuraxial anesthesia became the norm, rather than general anesthesia.

•In another series of 129 cases of suspected abnormally invasive placenta between 1997 and 2015 in a tertiary care referral center, neuraxial anesthesia was used at the start in 122 cases, and conversion to general anesthesia was required in 15 of those [27]. There were no complications of conversion to general anesthesia, although three required advanced airway management techniques to achieve endotracheal intubation (eg, awake fiberoptic intubation, videolaryngoscopy, gum-elastic bougie). Cesarean hysterectomy occurred in 72 cases.

In one institution the typical anesthetic for CD with placenta accrete spectrum has evolved from lumbar epidural or CSE to a double epidural catheter technique (lumbar CSE plus a thoracic epidural catheter) [28]. The thoracic catheter is placed to provide anesthesia for supraumbilical extension of the incision. In a retrospective review of the cases performed over approximately 20 years, conversion to general anesthesia was more common after CSE compared with the double catheter technique (29.7 versus 5.7 percent), based on a small number of cases (37 and 35, respectively) [28].  

Advantages of neuraxial anesthesia are those that relate to any cesarean delivery, including the following:

•Allows the parturient to be awake for the delivery

•Minimizes medication transfer to the fetus

•Avoids airway instrumentation

•Provides a means for postoperative analgesia, with neuraxial opioids

Disadvantages of neuraxial anesthesia for these procedures include the following:

•These may be long cases, and the dissection and surgical manipulation are more stimulating than during a routine cesarean delivery. Supplementation with sedatives or induction of general anesthesia may be required for pain, nausea, and vomiting.

•Induction of general anesthesia may become necessary during surgery after large volumes of IV fluid have been administered, increasing the risk of airway edema and difficult intubation.

•If general anesthesia becomes necessary because of massive hemorrhage, the sympathectomy induced by neuraxial block may increase the risk of severe hypotension or cardiovascular collapse with induction of anesthesia. (See 'Induction of anesthesia with postpartum hemorrhage' above.)

If neuraxial anesthesia is chosen as the primary anesthetic, a plan should be in place for safe conversion to general anesthesia if it becomes necessary [21]. The epidural catheter should only be removed when coagulation is confirmed to be normal if significant hemorrhage occurs.

●General anesthesia – Controlled preoperative induction of general anesthesia is preferred in the following circumstances:

•Patients with anticipated difficult intubation, severe obesity, or other characteristics that would make emergent intraoperative induction of general anesthesia unsafe

•Practice settings without availability of multiple anesthesia clinicians who can assist with simultaneous conversion to general anesthesia and management of massive blood transfusion

•Expectation of a difficult surgical procedure (eg, prolonged resection of pelvic organs for placenta percreta)

•Patient preference or extreme anxiety

●Combined approach – A planned, combined approach is also possible. Neuraxial anesthesia can be used for the delivery, with planned induction of general anesthesia immediately after the parturient sees her baby.

Anesthesia for arterial catheterization for embolization — In some centers, balloon-tipped catheters are placed in the internal iliac or uterine arteries via the femoral arteries preoperatively to control hemorrhage after delivery. Some centers have the capacity to complete a cesarean hysterectomy in the interventional radiology suite [29,30]. (See "Placenta accreta spectrum: Management", section on 'Endovascular intervention for hemorrhage control'.)

Appropriate venous access, arterial catheter placement, and blood product preparation should occur prior to balloon catheter placement; rarely, balloon catheter insertion may precipitate fetal bradycardia and urgent delivery [31].

If an epidural catheter is going to be used to provide anesthesia and perioperative analgesia, it should be sited prior to femoral catheter insertion since the patient will not be able to flex her hips to position for epidural placement with femoral catheters in place. The epidural catheter can then be used to provide analgesia for balloon catheter insertion.

Management of anesthesia for cesarean hysterectomy

General anesthesia — Rapid sequence induction and intubation should be performed as it would be for cesarean delivery. (See "Anesthesia for cesarean delivery", section on 'General anesthesia'.)

The interval from induction of anesthesia until delivery of the fetus is longer during cesarean hysterectomy than in a routine cesarean delivery because the surgeon must examine the uterus and plan the hysterotomy. After induction, adequate depth of anesthesia should be maintained to prevent awareness with recall, and the neonatal resuscitation team should be prepared to support a potentially anesthetized neonate.

If general anesthesia is required during a neuraxial anesthetic, the principles described for induction during PPH apply. For maintenance of anesthesia, we often keep the concentration of volatile anesthetic ≤0.5 minimum alveolar concentration (MAC) to assure unconsciousness but minimize vasodilation and cardiovascular effects. (See 'Induction of anesthesia with postpartum hemorrhage' above.)

Neuraxial anesthesia — A catheter-based technique (ie, epidural or CSE) is preferred for neuraxial anesthesia for cesarean hysterectomy to allow prolongation and extension of the neuraxial block. The neuraxial technique is the same as it would be for cesarean delivery without hysterectomy. (See "Anesthesia for cesarean delivery", section on 'Epidural anesthesia' and "Anesthesia for cesarean delivery", section on 'Combined spinal-epidural anesthesia'.)

Following delivery, neuraxial block should be maintained at adequate height (ie, T4) and density. Light sedation is often necessary, and a comfortable pillow helps the patient tolerate being awake.

Uterotonic drugs — With a fundal uterine incision, the controlled infusion of oxytocin may facilitate myometrial contraction, spiral arterial compression, and reduced blood loss. (See "Postpartum hemorrhage: Medical and minimally invasive management", section on 'Administer additional uterotonic medications'.)

Oxytocin requires refrigeration to maintain efficacy. In clinical circumstances in which refrigeration is not possible, heat stable carbetocin may be used as an alternative. (See "Management of the third stage of labor: Prophylactic pharmacotherapy to minimize hemorrhage", section on 'Active management in resource-limited settings'.)

Once the surgeons devascularize the uterus, systemic uterotonics can be discontinued.

Postoperative analgesia — A multimodal strategy for postoperative pain control should be employed, as it would be for other intra-abdominal surgery. (See "Approach to the management of acute pain in adults".)

SYSTEMS LEARNING FOR OBSTETRIC HEMORRHAGE — We agree with the Joint Commission on Accreditation of Healthcare organizations recommendation that obstetrical staff should undergo team training and clinical drills and conduct debriefing after postpartum hemorrhage (PPH). (See "Overview of postpartum hemorrhage", section on 'Training and simulation'.)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Obstetric hemorrhage" and "Society guideline links: Obstetric anesthesia".)

SUMMARY AND RECOMMENDATIONS

●Peripartum hemorrhage is an obstetrical emergency that requires a team-based, structured approach to management. Keys to management include recognition of excessive bleeding before it becomes life threatening, identification of the cause, and appropriate intervention. We suggest the use of a stage-based, unit-standard obstetric hemorrhage emergency management plan with checklists (table 3) (Grade 2C). (See 'Multidisciplinary care and coordination' above.)

●Antenatal anesthesia consultation should be arranged for patients at high risk of peripartum hemorrhage. Preanesthesia evaluation should include the usual medical and prenatal history, airway assessment, anesthesia-directed physical examination, and assessment of factors that may make blood transfusion problematic. (See 'Preanesthesia evaluation' above.)

●Neuraxial anesthesia is usually the preferred technique for instrumental and cesarean delivery and for most procedures performed for postpartum hemorrhage (PPH). For patients who are or have been bleeding, the following concerns regarding neuraxial anesthesia apply (see 'General concerns' above):

•The sympathectomy that accompanies neuraxial anesthesia can cause profound hypotension in severely hypovolemic patients. Patients who are or have been bleeding should be resuscitated with intravenous (IV) fluid and vasopressors prior to initiation of neuraxial anesthesia. For hemodynamically unstable patients, general anesthesia is preferred.

•Neuraxial anesthesia may be contraindicated for patients who develop a dilutional or consumptive coagulopathy because of increased risk of spinal epidural hematoma.

●Rapid sequence induction and intubation should be performed for general anesthesia for PPH. Induction of general anesthesia can also result in profound hypotension and cardiac arrest.

Hypovolemic patients should be resuscitated with IV fluid and supported with vasopressors prior to and during induction of general anesthesia. We administer etomidate or ketamine for induction, rather than propofol, to minimize the chance of hypotension. (See 'General concerns' above.)

●We suggest administration of tranexamic acid (TXA; 1 g IV over 10 to 20 minutes) along with oxytocin and other uterotonics for women with PPH diagnosed within three hours of delivery. TXA reduces death due to PPH without an increase in adverse events. (See "Postpartum hemorrhage: Medical and minimally invasive management", section on 'Administer tranexamic acid'.)

●Patients with placenta previa are at risk for massive hemorrhage before, during, and after delivery and are at increased risk for morbidly adherent placenta. (See 'Placenta previa' above.)

●Placental abruption may cause disseminated intravascular coagulation; a complete blood count and coagulation studies should be performed prior to neuraxial anesthesia for these patients. (See 'Placental abruption' above.)

●Sedation for procedures for PPH should be no deeper than moderate sedation, which means that the patient responds purposefully to verbal commands and maintains and protects her own airway. (See 'Moderate sedation/analgesia for postpartum hemorrhage' above.)

●Depending on specific clinical circumstances, cesarean hysterectomy can be performed with general anesthesia, neuraxial anesthesia, or a combination of the two. (See 'Choice of anesthetic technique' above.)

•A catheter-based neuraxial anesthetic may be appropriate for cesarean hysterectomy when the anticipated risk of massive blood loss is low. A safe plan should be in place for conversion to general anesthesia if it becomes necessary. (See 'Neuraxial anesthesia' above.)

•Controlled preoperative induction of general anesthesia for cesarean hysterectomy is preferred in the following circumstances:

-For patients with anticipated difficulty with airway management

-Expectation of difficult or prolonged surgery

-Lack of additional anesthesia clinicians who could assist with conversion to general anesthesia during neuraxial anesthesia

-Extreme patient anxiety (see 'General anesthesia' above)

●Massive hemorrhage is always possible during cesarean hysterectomy. We prepare for hemorrhage as follows (see 'Preparation for transfusion' above):

•We place two large-bore IV catheters for volume administration. We also place a central venous catheter (CVC) or a peripherally inserted central catheter for administration of potent vasopressors and calcium chloride. (See 'Venous access' above.)

•We coordinate a planned massive transfusion with the blood bank and obtain the first cooler of blood products for storage in the operating suite prior to surgical incision.

•We consider the use of intraoperative cell salvage.