Anaethetic management of obstetric haemorrhage

1. ANAESTHETIC MANAGEMENT OF OBSTETRIC haemorrhage By Dr.Sasidhar Moderated by Dr.Ravimohan A ssoc professor ASRAM MEDICAL COLLEGE , Eluru

2. 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

3. 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

4. Antepartum haemorrhage Common causes placenta previa placental abruption uterine rupture vasa previa

5. 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

6. etiology Advancing maternal age Multiparity Multifetal gestations Prior cesarean delivery Smoking Prior placenta previa

7. 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 .

8. 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

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

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

16. 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

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

18. Obstetric management definitive treatment is delivery of the fetus and placenta

19. 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

20. 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 Pa o 2 and pH during untreated hemorrhage (20 mL/kg )

21. 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 i nducing 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

22. 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.

23. 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

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

25. 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

26. vasaprevia O ccurs 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. H ighest foetal mortality rates 50 % to 75 % No threat to the mother Early diagnosis and treatment are essential to reduce the chance of foetal death R equires immediate delivery by caesarean section Neonatal resuscitation, neonatal volume replacement Choice of anaesthetic technique depends on the urgency of caesarean section

27. 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 postpartum Causes Uterine atony Genital trauma Coagulopathy Placental abnormalities

28. 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

29. 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).

30. prostaglandin E2 vaginal or rectal suppository 20mg every 2hrly causes bronchodilation decreased SVR and blood pressure increased heart rate , cardiac output prostaglandin F 2-alpha increases cardiac output increases systemic and pulmonary artery pressures Increased Pa co 2 and decreased Pa o 2 alterations of ventilation/perfusion ratios bronchospasm 15-Methyl prostaglandin F 2-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 .

31. Misoprostol 800 -1000 mcg rectally prostaglandin E 1 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

32. 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

33. 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

34. 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

35. 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

36. Placenta accreta

37. 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

38. 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

39. 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 F 2-alpha ) may be needed

40. 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

41. 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

42. 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 haemorrhage Tissues are oedematous and congested Amount 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

43. 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

44. 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

45. 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

46. 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

47. references Chestnut: Obstetric Anesthesia: Principles and Practice, 3rd ed . By David H. Chestnut,  M.D Miller’s Anesthesia , 7 th edition

48. Thank you