ANAESTHETIC MANAGEMENT OF OBSTETRIC HAEMORRHAGE

By

Dr.Sasidhar

Moderated by

Dr.Ravimohan

Assoc professor

ASRAM MEDICAL COLLEGE , Eluru

OBSTETRIC HAEMORRHAGE

Worlds leading cause of maternal mortality

Major obstetric haemorrhage complicates up to 10.5% of all births

In India obstetric haemorrhage contributes to 22.34% of all maternal deaths

Obstetric haemorrhage is can be classified as Antepartum haemorrhage defined as bleeding from vagina after 24 wks. of gestation and before delivery Post partum haemorrhage defined as blood loss within 24hrs of delivery which is more than 500ml following vaginal delivery ,more than 1000ml following caesarean section

ANTEPARTUM HAEMORRHAGE

Common causes placenta previa placental abruption uterine rupture vasa previa

PLACENTA PREVIA placenta previa is present when the placenta

implants in advance of the foetal presenting part incidence of placenta previa is approximately 1 in 200

pregnancies total placenta previa ---completely covers the cervical

os partial placenta previa--- covers part, but not all of

the cervical os marginal placenta previa ---lies close to, but does not

cover the cervical os

ETIOLOGY

Advancing maternal ageMultiparityMultifetal gestationsPrior cesarean deliverySmokingPrior placenta previa

The most characteristic event in placenta previa is painless hemorrhage.

This usually occurs near the end of or after the second trimester.

The initial bleeding is rarely so profuse as to prove fatal.

It usually ceases spontaneously, only to recur.

Placenta previa may be associated with placenta accreta, placenta increta or percreta.

Coagulopathy is rare with placenta previa.

DIAGNOSIS

should always be suspected in women with uterine bleeding during the latter half of pregnancy.

appropriate evaluation, including sonography

examination of the cervix is never permissible unless the woman is in an operating room with all the preparations for immediate cesarean delivery, because even the gentlest examination of this sort can cause torrential hemorrhage.

safest method is transabdominal sonography. MRI At 18 weeks, 5-10% of placentas are low lying.

Most ‘migrate’ with development of the lower uterine segment

OBSTETRIC MANAGEMENT

Vaginal examinations are best avoided If needed done under double setup Expectant management Surgical management

ANAESTHETIC MANAGEMENT

For Double Set-Up examination Rarely performed performed in the operating room full preparation for cesarean section which

includes maternal monitors, insertion of two large-gauge intravenous cannulae, administration of a nonparticulate antacid sterile prep , draping of the abdomen Two units of packed red blood cells (PRBCs

FOR CAESAREAN SECTION

choice of anaesthetic technique depends on the indication and urgency for caesarean section and the degree of maternal hypovolemia

High risk of intra operative blood loss due to

obstetrician may cut into the placenta during uterine incision lower uterine segment implantation site does not contract well increased risk for placenta accreta

A retrospective study with 350 cases of placenta previa [ 60 % regional , 40 % GA ] found

decraesed EBL with RA vs. GA decrased transfusions needs with RA no difference in hypotension N Parekh et al Br J Anaesth 2000;84;725

PREOPERATIVE PREPARATION

patient evaluation, resuscitation, and preparation for operative delivery all proceed simultaneously

careful assessment of the parturient's airway and intravascular volume

Two large-gauge intravenous catheters four units of PRBCs Blood administration sets fluid warmers equipment for invasive monitoring

Rapid-sequence induction of general anesthesia is the preferred technique

avoid sodium thiopental propofol should not be used in

hypovolemic patients Ketamine (0.5 to 1.0 mg/kg) and

etomidate (0.3 mg/kg) are the best induction agents for bleeding patients

patients with severe hypovolemic shock, intubation may require only a muscle relaxant

MAINTENANCE

nitrous oxide and oxygen with a low concentration of a volatile halogenated agent

concentration of nitrous oxide can be reduced (or omitted) in cases of foetal distress

Oxytocin (20 U/L) immediately after delivery lower uterine segment implantation site does

not contract as well as the fundus All uterine relaxants should be eliminated if

bleeding continues best to eliminate the volatile halogenated

agent after delivery substitute nitrous oxide (70%) and an

intravenous opioid

ABRUPTIO PLACENTA

Placental abruption is defined as separation of the placenta from the decidua basalis before delivery of the foetus

Incidence 1 in 100 pregnancies Risk factors hypertension advanced age and parity tobacco use cocaine use trauma premature rupture of membranes a history of previous abruption

Presentation vaginal bleeding uterine tenderness increased uterine activity complications haemorrhagic shock acute renal failure (ARF) Coagulopathy, DIC foetal distress or demise

OBSTETRIC MANAGEMENT

definitive treatment is delivery of the fetus and placenta

degree of abruption is minimal the fetus shows no signs of distressMaternal haemodynamics stable

Hospitalisation Foetal HR monitoringSerial ultra sonographyMaternal haemodynamic monitoring

Delivered after foetal lung maturation

ANAESTHETIC MANAGEMENT

Preoperative preparation airway assessment Assessment of volume status Maternal Haemodynamic monitoring FHR monitoring Two large bore IV catheters Blood for cross matching , haematocrit ,

coagulation Maintain supplemental oxygen Left uterine displacement

FOR LABOUR AND NORMAL DELIVERY Epidural analgesia can be given only if

coagulation studies are normal

no intravascular volume deficit Vincent et al.[36] observed that epidural anesthesia

significantly worsened maternal hypotension, uterine blood flow, and fetal PaO2 and pH during untreated hemorrhage (20 mL/kg)

CAESAREAN SECTION

General anaesthesia is preferred for most of the cases

Regional anaesthesia can be given for a patient with stable haemodynamics ,good intravascular volume ,minor abruption, NO foetal distress

Ketamine and etomidate are inducing agents of choice

Rapid sequence induction is preferred Large doses of ketamine may increase

uterine tone during early gestation So dose of ketamine should be limited to

single dose of 1mg/kg

Aggressive volume resuscitation with both crystalloids and colloids

Blood transfusion Central venous catheter and arterial catheter

may be necessary High risk for uterine atony and coagulopathy Oxytocin 20U/L infused immediately after the

delivery Coagulation abnormalities may require FFP Recover quickly and completely after delivery prolonged hypotension, coagulopathy, and

massive blood volume/product replacement, are best monitored in a multidisciplinary intensive care unit.

UTERINE RUPTURE Rupture of the gravid uterus can be

disastrous to both the mother and foetus It may be of two types uterine scar dehiscence complete uterine rupture Scar dehiscence foetal distress less common no excessive haemorrhage rarely requires emergency section Uterine rupture foetal distress massive haemorrhage requires emergency caesarean section

Presentation vaginal bleeding hypotension cessation of labour foetal distress Obstetric management uterine repair uterine artery ligation hysterectomy – definitive treatment

ANAESTHETIC MANAGEMENT

Preoperative evaluation , resuscitation and preparation of OT simultaneously

GA is often required RA can be given in haemodynamically

stable patients , who already have a epidural catheter ,absence of foetal distress

Aggressive volume replacement maintenance of urine output Invasive hemodynamic monitoring

VASAPREVIA Occurs rarely 1 in 2000 to 3000 deliveries. Vasa previa is associated with a velamentous

insertion of the cord where foetal vessels traverse the foetal membranes ahead of the foetal presenting part.

Highest foetal mortality rates 50% to 75% No threat to the mother Early diagnosis and treatment are essential to

reduce the chance of foetal death Requires immediate delivery by caesarean section Neonatal resuscitation, neonatal volume

replacement Choice of anaesthetic technique depends on the

urgency of caesarean section

POST PARTUM HAEMORRHAGE

Major cause of maternal morbidity and mortality

Types Primary postpartum haemorrhage occurs

during the first 24 hours after delivery secondary postpartum haemorrhage occurs

between 24 hours and 6 weeks postpartumCauses Uterine atony Genital trauma Coagulopathy Placental abnormalities

UTERINE ATONY

Risk factors Multiple gestation Macrosomia Polyhydramnios High parity Chorioamnionitis Precipitous labor Augmented labor Tocolytic agents High concentration of a volatile agents Prolonged labor

OXYTOCIN first-line drug for the prophylaxis or treatment of

uterine atony Endogenous oxytocin is a 9-amino acid polypeptide

produced in the posterior pituitary exogenous form is a synthetic preparation 20 U of oxytocin to a litre of NS or RL started as

infusion Bolus administration of oxytocin causes peripheral

vasodilation, hypotension Weis et al.[53] administered oxytocin 0.1 U/kg

intravenously to pregnant women in the first trimester. They noted that heart rate increased, MAP decreased by 30%, and total peripheral resistance decreased by 50%

Secher et al.[54] noted that bolus intravenous administration of 5 or 10 U of oxytocin increased pulmonary artery pressures in pregnant women

cardiovascular changes are short lived (less than 10 minutes).

prostaglandin E2

vaginal or rectal suppository 20mg every 2hrly

causes bronchodilation

decreased SVR and blood pressure

increased heart rate , cardiac output

prostaglandin F2-alpha

increases cardiac output

increases systemic and pulmonary artery pressures

Increased PaCO2 and decreased PaO2

alterations of ventilation/perfusion ratios

bronchospasm

15-Methyl prostaglandin F2-alpha (carboprost)

preferred for the treatment of refractory uterine atony

250 μg administered intramuscularly or intramyometrially

Bronchospasm

disturbed ventilation/perfusion ratios

increased intrapulmonary shunt fraction

hypoxemia.

Misoprostol

800 -1000 mcg rectally

prostaglandin E1 analogue

effective treatment for postpartum haemorrhage unresponsive to oxytocin and ergometrine

Ergot alkaloids

0.2mg iv every 2-4 hrs

Ergonovine and methylergonovine

restricted to postpartum use

rapidly produce tetanic uterine contraction

act on alpha-adrenergic receptors

Cause vasoconstriction, hypertension, Pulmonary artery pressure , Pulmonary oedema

GENITAL TRAUMA Most common injuries at childbirth are lacerations

and hematomas of the perineum, vagina, and cervix Pelvic hematomas are three types:

vaginal, vulvar, and retroperitoneal

signs and symptoms

restlessness,

lower abdominal pain,

a tender mass above the inguinal ligament

vaginal bleeding

abrupt hypotension

Ileus

unilateral leg oedema

urinary retention

haematuria

ANAESTHETIC MANAGEMENT OF GENITAL TRAUMA

For vulval haematomas and small lacerations

Local infiltration and a small dose of intravenous opioid

For extensive lacerations and vaginal haematomas

pudendal nerve block – technically may not be feasible

neuraxial blockade – may cause hypotension

MAC – most preferred

N2O ,O2 with inhalational agents

low dose ketamine

For retroperitoneal haematoma

laparotomy with general anaesthesia

rapid sequence induction

difficult intubation to be anticipated

RETAINED PLACENTAL PRODUCTS

Retained placental fragments are a leading cause of both early and delayed postpartum hemorrhage

OBSTETRIC MANAGEMENT

manual removal and inspection of the placenta

After removal of the placenta, uterine tone should be enhanced with oxytocin

ANAESTHETIC MANAGEMENT OF RETAINED PLACENTAL PRODUCTS

If epidural catheter is in situ additional local anaesthetic drug can be given

Subarachnoid block can be given if patient is haemodynamically stable

Nitrous oxide analgesia Low dose ketamine GA can be given with rapid sequence

induction Methods to facilitate uterine relaxation halogenated inhalational agents nitroglycerine

PLACENTA ACCRETA

Placenta accreta vera is defined as adherence to the myometrium without invasion of or passage through uterine muscle

Placenta increta represents invasion of the myometrium

Placenta percreta includes invasion of the uterine serosa or other pelvic structures

Risk factors previous uterine trauma previous caesarean section low lying placenta Diagnosis antepartum diagnosis is rare difficulty in removal placenta ultrasonography MRI transvaginal colour dopler

Obstetric management uterine curettage, followed by over-sewing of

the bleeding placental bed. Balloon occlusion embolization techniques postpartum hysterectomy – definitive Anaesthetic management preoperative diagnosis of placental abnormalities identifying patients with high risk for placenta

accreta preparation for hysterectomy availability of blood products

UTERINE INVERSION Turning inside out of all or part of the uterus Occur in 1 In 5000 to 1 in 10,000 pregnancies Risk factors

uterine atony

inappropriate fundal pressure

umbilical cord traction

uterine anomalies.

An abnormally implanted placenta

(i.e., placenta accreta) Obstetric management

Early replacement of the uterus is the best treatment

Once the uterus has been replaced.

Oxytocin (20 U/L) should be infused initially,

additional drugs (15-methyl prostaglandin F2-alpha)

may be needed

ANAESTHETIC MANAGEMENT OF UTERINE INVERSION uterine tone precludes immediate replacement, uterine relaxation is needed before successful

replacement can be performed Ideal technique should have

rapid uterine relaxation

no side effects

short duration

restoration of uterine tone after replacement of the uterus GA with inhalational agents most preferred Equipotent doses of all volatile halogenated agents

produce a similar degree of uterine relaxation Endotracheal intubation is mandatory Other modes

terbutaline, magnesium sulfate, organic nitrates

INVASIVE TREATMENT FOR OBSTETRIC HAEMORRHAGE Includes angiographic arterial embolization balloon occlusion surgical arterial ligation hysterectomy Embolization local anaesthesia complications are few preservation of fertility is likely Can be done in presence of a coagulopathy Requires rapid access to angiographic facility Requires skilled radiologist Logistic problems

Bilateral surgical ligation uterine, ovarian, and internal iliac arteries preservation of fertility damage to other pelvic structures (ureter) vascular anatomy is variable lower extremity ischemia postpartum hysterectomy definitive treatment for postpartum haemorrhageTissues are oedematous and congestedAmount of blood loss is more multicentre review showed that the average

blood loss for emergent cases was 2526 mL, with an average transfusion requirement of 6.6 units of blood

ANAESTHETIC MANAGEMENT obstetrician requires good skeletal muscle relaxation and a quiet

operative field Choice of technique Regional anaesthesia

Risk of hypotension

The operative time for caesarean hysterectomy is more

patient may have fatigue and restlessness.

Intraperitoneal manipulation, dissection, and traction result in pain,

nausea, and vomiting.

hyperemic pelvic viscera with engorged, edematous vasculature

require careful dissection facilitated by a quiet operative field If RA is given then

Maintenance of a T-4 sensory level

prophylaxis against nausea and vomiting

judicious sedation Most of the cases require GA for emergency obstetric hysterectomy

Regardless of the anaesthetic technique used two large-gauge intravenous catheters at least two units of packed PRBCs should be immediately available. Additional units should be available without delay. Vasoactive drugs (e.g., phenylephrine, dopamine, epinephrine).establish invasive monitoring. A fluid warmer equipment for rapid infusion of fluids

RECENT ADVANCES

Intra operative cell salvage Chance of amniotic fluid embolism

Haemolytic disease in future pregnancies

Leukocyte depletion filter is useful

Separate suction for amniotic fluid advised Thromboelastography Useful guide in massive haemorrhage

Provides information regarding coagulation factors , platelet function, fibrinogen levels , fibrinolysis

Rapid results

Can be done near the patient

Role of tranexaemic acid Antifibrinolytic

1gm IV stat dose

Followed by a second dose after 30 min if bleeding doesn’t stop

World maternal antifibrinolytic trail Recombinant factor VIIa useful in unresponsive massive haemorrhage

Coagulopathy has to be corrected prior

Prerequisites

platelet count >50,000

fibrinogen > 0.5gms /L

ph. >7.2

Dose – 90 mcgs/kg stat dose

followed by 120 mcg/kg if bleeding persists

Thromboembolic events can occur

High cost , lack of availability

REFERENCESChestnut: Obstetric Anesthesia: Principles and Practice, 3rd ed. By David H. Chestnut, M.D

Miller’s Anesthesia , 7th edition

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