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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
THANK YOU
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