Anesthesia Management for A Patient with Placenta Accreta Undergoing Cesarean Section

1. Anesthesia Management for A Patient with Placenta Accreta Undergoing Cesarean Section By R2 彭育仁

2. Brief History(1) • This 34 y/o woman, G4P1AA2, AP 32+wks, was admitted for elective Cesarean Section on 91-10-7 due to highly-suspected placenta accreta. • She was rather well before. C/S was performed 11 years ago due to giant baby and post-op course was smooth.

3. Brief History(2) • During this time of pregnancy, she was suffered from several times of APH and uterine contraction and hospitalized for tocolysis. Ultrasonography showed placenta previa and placenta accreta was highly suspected.

4. Brief History(3) • After admission, two 5 French (8mmID) RCI balloon catheters were placed at bilateral internal iliac artery under fluoroscopy by radiologist on 10/8. • Before operation, Hb is 9.9, no thrombycytopenia and PT, PTT are WNL.

5. Anesthesia and Operation Management(1) • Combined spinal-epidural (CSE) anesthesia was performed initially for bilateral double J insertion by urologist before C/S and post-op pain control. Arterial line was set up. • After obstetrician were prepared, general endotracheal anesthesia was induced with thiopental, ketamine and succinylcholine. N2O (50%) and Isoflurane (0.5%) were used to maintain general anesthesia. 14x14 CVP was inserted via r’t IJV.

6. Anesthesia and Operation Management(2) • After the delivery of the baby (Ag 5~8), bilateral internal iliac artery catheter balloons were dilated. Placenta accreta in anterior low segment of uterus and severe adhesion were noted followed by Cesarean hysterectomy. • Peri-op vital signs were stable under aggressive fluid replacement. Hb has ever drop from 10.4 to 8.3

7. Anesthesia and Operation Management(3) • Input: Blood transfusion with whole blood 6u, HAES 500ml, crystalloid 2500ml • Output: Estimated blood loss: 3500ml, U/O 1200ml • After the operation, she was extubated and then transferred to SICU for post-op care.

8. Post-op Care • She stayed at SICU for 1 day. Hb 8.0 was noted and PRBC 4u was transfused. The catheter balloons were kept inflated for 1 day and removed after achieving hemostasis. Double J were left for 2 days. • The post-op course was smooth and she was discharged on the 6th post-op day.

9. Obstetric Hemorrhage • Obstetric hemorrhage remains a leading cause of maternal mortality and morbidity, followed by embolism and pregnancy-induced hypertension. • Understanding maternal adaptations to pregnancy and response to blood loss, pathophysiology, and management of massive hemorrhage can improve outcome.

10. Placenta Accreta(1) • 殖入性胎盤 • Incidence: ~1 per 2500 deliveries. • Placenta is unusually adherent to implantation site, with absent decidua. • The physiologic line of cleavage through the decidual spongy layer is lacking. • Placenta accreta/increta/percreta 粘連性/穿入性/穿透性

12. Placenta Accreta(2) • Risk Factors: • Previous C/S or other previous uterine incisions • Repeated uterine curettage. • Placenta previa. • A history of manual extraction of placenta. • High parity and increasing maternal age.

13. Placenta Accreta(3) • Placenta accreta is noted at the time of delivery or C/S with difficulty in separating the placenta from uterine wall. • Ultrasonography can diagnose 78% to 100% of cases. • Antenatal recognition of placenta accreta and careful planning by obstetrician and anethesiologist can decrease blood loss and reduce serious complications.

14. Obstetric Management • Elective cesarean section. • Anticipation of significant blood loss (sewing the placenta implantation site, uterine artery or internal iliac artery ligation) and high probability of cesarean hysterectomy. • Better preparation before op (autologous blood transfusion, pre-op catheterization for subsequent uterine artery balloon occlusion).

15. Prophylactic Internal Iliac Artery Balloon Occlusion in Abnormal Placentation(1) • Purposes: 1. to stop hemorrhage so that hysterectomy is avoided and fertility is reserved. 2. to decrease obstetric hemorrhage prior to hysterectomy, so that bleeding vessels are better identified and intraoperative blood loss is decreased.

17. Prophylactic Internal Iliac Artery Balloon Occlusion in Abnormal Placentation(2) • Occlusion of internal iliac arteries does not halt blood flow to uterus because there is a rich blood supply of collaterals. However this technique dose reduce pulse pressure distal to the occlusion site, thus minimizing blood loss during hysterectomy.

18. Anesthetic Management Elective cesarean hysterectomy(1) • Chestnut and Redick: 7/25 of epidural anesthesia required intra-op general anesthesia. The causes were patient discomfort and inadequate operative conditions: longer operative time, excessive intraperitoneal manipulation (pain, vomiting), and engorged edematous vasculature requires careful dissection.

19. Anesthetic Management Elective cesarean hysterectomy(2) • Chestnut et al: after trying to overcome the problem above, the authors concluded that continuous epidural anesthesia is not contraindicated. • There is always a possibility that immediate conversion from regional anesthesia to general anesthesia will be required during acute hemorrhagic crisis.

20. Anesthetic Management Elective cesarean hysterectomy(3) • To have the airway secured might make anesthesiologist focus on hemodynamic management. • It is important to have adequate personnel available when one proceeds with continuous epidural anesthesia. • In this case, regional anesthesia may be suitable.

21. Anesthetic Management Elective cesarean hysterectomy(4) • Possibility of perioperative coagulation disorders such as DIC must be concerned although DIC is more often during emergent hysterectomy. • If possible, the epidural catheter should be removed after the patient’s coagulation status is normal or back to baseline.

22. Anesthetic Management Emergency cesarean hysterectomy(1) • Placenta accreta was the most frequent indication for emergency peripartum hysterectomy (more than half). • The estimated blood in emergency cesarean hysterectomy was 2526士1240ml, which is significantly more than in elective cesarean hysterectomy (1319士396ml). The blood loss among patients varies significantly.

23. Anesthetic Management Emergency cesarean hysterectomy(2) • When uncontrolled hemorrhage happened, hysterectomy becomes necessary. • Anesthetic management starts with the evaluation of airway and oxygenation, and establishment of large-bore IV access. • Conversion from regional to general anesthesia is not always necessary but appropriate when the ongoing blood loss is significant.

24. Management of Massive Hemorrhage(1) • Assessment of blood loss is somewhat difficult in parturients because of the increased blood volume (increase 45%) during pregnancy and concomitant use of vasoactive drugs. • Hypotension is usually a late sign of blood loss, as heart rate increases in parturients to compensate blood loss.

26. Management of Massive Hemorrhage(2) • Hb or Hct are not very helpful in determining the degree of blood loss in acute phase and they are not immediately decrease during acute blood loss. • At least two large-bore IV lines in upper trunk is necessary (compression of IVC). • Colloid solution is more efficacious in fluid resuscitation.

27. Management of Massive Hemorrhage(3) • The amount of crystalloid necessary to replace the blood loss is approximately three times of the amount lost. • ASA Practice Guidelines for Blood Component Therapy stated that RBC transfusion is usually indicated when the Hb level is less than 6.

28. Management of Massive Hemorrhage(4) • A parturient with Hb of 3 g/dL due to abruptio placentae and DIC has been reported. Both mother and the baby survived without sequelae. • Maintenance of normovolemia is very important for parturients to compensate for anemia.

29. Management of Massive Hemorrhage(5) • Massive transfusion can cause dilutional thrombocytopenia and coagulopathy, which can be treated with appropriate blood component (FFP, Plt). • Other complications as hyperkalemia, citrate intoxication (resultant hypocalcemia), and hypothermia may need special treatment.

30. Blood Conservation Technique(1) • To protect parturients from the risks of homologous blood transfusion. • Autologous blood donation (500~1000ml pre-op) can decrease blood transfusion rate in high risk of paturients. Erythropoietion may be administered to pregnant patients to compensate for loss of blood by autologous blood donation.

31. Blood Conservation Technique(2) • Acute normovolemic hemodilution: 750 to 1000ml of blood collection was replaced by an equal amount of 10% pentastarch just before the operation. All the blood was reinfused at the end of operation or before. • Intraoperative blood salvage may not cause amniotic fluid embolism or DIC in a recent report. Cell savers can effectively separate amniotic fluid from blood.

32. Other Causes of Obstetric Hemorrhage(1) • Abruptio placentae 胎盤早期剝離: premature separation of the normally implanted placenta. Concealed hemorrhage can cause DIC and the extent of hemorrhage is underestimated. Normal blood pressure can be misleading, as pregnancy-induced or chronic hypertension is associated with abruption. It is important to detect coagulopathy before operation and it may make general anesthesia indicated.

34. Other Causes of Obstetric Hemorrhage(2) • Placenta previa 前置胎盤: abnormal location of placenta over or very near the internal os. The incidence is around 1 in 200 deliveries. The progression of pregnancy results in a shearing force between uterine wall the nonelastic placenta and bleeding is inevitable with cervical dilation. Anesthetic management of such patients depends on the urgency and the severity of hemorrhage.

36. Other Causes of Obstetric Hemorrhage(3) • Uterine rupture 子宮破裂: a full thickness defect of the uterine wall. It may be spontaneous, secondary to trauma or previous uterine scar. • Uterine atony 子宮無力 • Retained placenta 滯留性胎盤 • Inversion of the uterus 子宮外翻 • Vasa previa 前置血管

37. Summary(1) • Obstetric hemorrhage remains a leading cause of maternal death. • Owing to the increase is circulating blood volume, parturients do not demonstrate blood pressure changes, even after moderate blood loss. Visual assessment of blood loss is often misleading and hypotension is often a late sign.

38. Summary(2) • Antenatal diagnosis (ultrasonography for placenta accreta), preoperative preparation (autologous blood transfusion), prophylactic method to reduce blood loss (balloon occlusion), aggressive intervention for massive blood loss (ligation and fluid replacement), and a close team work to patient care can reduce maternal mortality and morbiditly.

39. Thank You