Eclampsia

1. Eclampsia Pathophysiology Management Anesthetic implications Dr. InduBodh University College of Medical Sciences & GTB Hospital, Delhi www.anaesthesia.co.in email: anaesthesia.co.in@gmail.com

2. Eclampsia • Associated with - maternal mortality of ~ 10% perinatal mortality and morbidity of 13 – 30 % • Life threatening emergency , most common in third trimester • Approxymately 60% of seizures precede delivery • Incidence higher in developing countries

3. Eclampsia Convulsion or coma not caused by coincidental neurologic disease, which occur during pregnancy or in the puerperium in a woman whose condition also meets the criteria for preeclampsia

4. Eclampsia Incidence : • antepartum (50%) • Intrapartum (25%) • postpartum (25%)

5. Eclampsia Risk factors : • Nulliparity • Multiple gestation • Molar pregnancy • Preexisting hypertension or renal disease • Previous severe preeclampsia or eclampsia • Systemic lupus erythematous

6. Eclampsia • Time of onset : 91% of cases → ≥ 28 wks of gestation 7.5% of cases → 21-27 wks of gestation 1.5% of cases → < 20th wks of gestation

7. Eclampsia Etiology : * unknown • Cerebral vasoconstriction or vasospasm • Cerebral infarction • Cerebral edema, cerebral hemorrhage • Metabolic encephelopathy

8. Pathogenesis: Imbalance of Vasodilatory substances (Prostacyclin, Nitric oxide) & Vasoconstrictive substances (Thromboxane A2, Endothelin) ↓ ↑ Vascular reactivity ↓ Vasospasm

9. Markers of endothelial injury→ • ↑ levels of fibronectin, thromboxane A2 , endothelin, TNF, IL 1, serotinin, lipid peroxidase, free radicals • ↓ nitric oxide, prostacyclin I2

10. Eclampsia Clinical manifestations : Headache, visual disturbances, epigastric or right upper quadrant pain ↓ Seizures abrupt onset, begin as facial twitching followed by tonic phase (15-20 sec) → clonic phase (60 sec) → postictal state Number of seizures varies from 1-2 to as many as 100 in severe untreated cases

11. The natural progression of the disease is from symptomatic severe preeclampsia to seizures. • Features include the following: Seizure or postictal state (100%) Headache (80%) Generalized edema (50%) Vision disturbance (40%) Abdominal pain with nausea (20%) Amnesia and other mental status changes

12. Physical examination: • Sustained SBP >160 mm Hg or DBP > 110 mm Hg • Tachycardia, Tachypnea • Rales • Mental status changes • Hyperreflexia • Clonus • Papilledema • Oliguria or anuria • Right upper quadrant or epigastric abdominal tenderness • Generalized edema • Small fundal height for the estimated gestational age

13. Eclampsia Conditions simulating eclampsia : Epilepsy, encephalitis Meningitis, cerebral tumor Cerebrovascular accidents Hyponatremia, hypocalcemia Hypoglycemia

14. Management of eclampsia Eclampsia Prevention of convulsions Control of convulsions

15. Prevention of convulsions MgSo4 therapy: DOC for prophylaxis of eclamptic convulsions M.O.A- blocks Ca2+ion influx in to neurons ↓ cerebral vasodilation Other actions : lowers endothelin-1 levels vasodilatory effect on vascular bed ↑ production of PG I2 tocolytic action attenuates the release of Ach at myoneural junction

16. control of convulsions 1). Stop convulsions ( inj. thiopentone 50-100mg, inj. Diazepam 2.5-5mg, inj. Midazolam 1-2mg) 2). Establish an airway 3). Turn patient to the left side; apply jaw thrust 4). Attempt bag and mask ventilation 5). Insert orophayrangeal airway if necessary 6). Maintain ventilation and oxygenation 7). Continue bag and mask ventilation 8). Apply pulse oximeter and monitor

17. control of convulsions 9). Maintain circulation with i.v fluids and secure intravenous access 10). Check blood pressure at frequent interval 11). Monitor electrographic recordings 12). Administer MgSO4 : 4gm of inj. MgSo4 → 1gm of inj MgSo4 per hour 13.) Control hypertension 14). Deliver the baby expeditiously 15). If convulsions do not terminate rapidly, intubate the patient with inj. Sch. 16). Convulsions are often associated with metabolic acidosis- sodium bicarbonate may be used

18. Recommended regimen of MgSo4 • Loading dose : 4-6 gm IV, over 20 mins • Maintenance dose : 1-2 gm/hr IV • Additional 2-3 gm over 5-10 mins. (1-2 times) if persistent convulsions • If seizures persist, 10 mg diazepam, thiopentone can be given • In status epilepticus : intubate with muscle relaxation • Therapeutic range : 4-8mg/dl

19. Serum Mg levels & asso. Clinical findings Serum Mg level Clinical finding • Loss of patellar reflex 8-12 mg/dl • Fleeing of warmth, flushing 9-12 mg/dl • Somnolence, Slurred speech 10-12 mg/dl • Muscular paralysis, respiratory difficulty 15-17 mg/dl • Cardiac arrest 30-35 mg/dl

20. Monitoring during MgSO4therapy • Clinical monitoring for : deep tendon reflexes hourly urine output • Renal function monitoring before or during therapy • Serial estimation of Serum Mg2+ levels • Urinary Mg2+ levels

21. Maternal and fetal effect of MgSO4 therapy • Maternal effect : Loss of deep tendon reflexes Fleeing of warmth, flushing Somnolence, Slurred speech Muscular paralysis Respiratory difficulty Cardiac arrest • Fetal effect : ↓ FHR ↓ muscle tone Respiratory depression Apnea

22. Management of Mg toxicity • Discontinue infusion • Oxygen supplementation • Serum Mg level • 1 gm Calcium gluconate (10 ml of 10 %) IV • Respiratory arrest - CPCR

23. Anesthetic implications • MgSo4 potentiate and prolong the action of both depolarizing non-depolarizing muscle relaxants • Mg+ has been shown to ↑es the bleeding time and ↓es the platelet activity • At higher doses Mg+ rapidly crosses the placental barrier, has been found to significantly ↓es FHR variabilty • Should be given cautiously with Ca2+ as may antagonize the anticonvulsant effect of MgSo4 • Also be cautious in patients with renal impairment • May ↑es the possibility of hypotension during regional block

24. Delivery in eclampsia Unless contraindicated, Eclamptic women should undergo normal vaginal delivery Indications for cesarean section – Fetal distress Placental abruption Extreme prematurity Unfavorable cervix Failed induction of labour Recurrent seizures

25. Choice of anesthesia Conscious, no signs of raised ICP or coagulopathy, controlled seizures Unonscious, evidence of ↑ed ICP or coagulopathy, uncontrolled seizures regional anesthesia general anesthesia

26. Preanesthetic assessment : Assessment of seizure control and neurologic function Airway patency Volume status Blood pressure control #Laboratory investigations – CBC, Bld.sugar, Bld urea. S.creatinine, uric acid level with S.E, LFTs, Coagulation profile, 24hrs specimen for protein

27. Premedication: Elective C.S – Tab ranitidine 150 mg H.S and M.O.S Tab Metoclopramide 10 mg H.S and M.O.S Emergency C.S - 0.3M Sodium Citrate, 30mL PO 30 min bfr Sx inj. Ranitidine 50 mg IV 30 min bfr Sx inj. Metoclopramide 10 mg 30 min bfr Sx

28. Intraoperative monitoring– ECG, NIBP,SPO2, EtCO2 ,CVP, Urine output, NM monitoring, Mg monitoring, FHS monitoring, PAC optional

29. Regional anesthesia in eclamptic pt. • Aspiration prophylaxis to be given • Blood and blood products to be arranged • Secure peripheral i.v line and CVP line, PAC optional • Preload with 500 ml of crsytalloid • If CVP < 4mmhg→ 500 ml of colloid over 10-15 mins ↓ if urine output >0.5ml/kg/hr,Crystelloid@80-90ml/hr if urine output<0.5ml/kg/hr, check CVP again if CVP< 4mmhg, 500ml of colloid over 10-15 mins • if CVP 5-10mmhg, crystalloid to be given • Monitor FHS until the beginning of surgery • Maintain the left uterine displacement

30. Regional anesthesia in eclamptic pt. • Continuous lumbar epidural – tech. of choice Advantage: Gradual onset of sympathetic block Improves uteroplacental blood flow Avoids neonatal depression ↓ circulating levels of cetacholamines Provides pain relief postoperatively also Avoids the risk of difficult intubation, ↑ B.P # Ensure - normal coagulation profile Adequate circulating volume

31. Regional anesthesia in eclamptic pt. • Subaracnoid Block: Requires only a small volume of local aesthetic Addition of opioids to reduce LA dose # Precautions: Adequate preloading to be ensured Avoid sudden hypotension Prompt treatment of hypotension

32. Regional anesthesia in eclamptic pt. • SEQUENTIAL CSE: • Intrathecal----bupivicaine 0.5%(H) 5-12.5mg + fentanyl 20-25mcg • Epidural ----bupivicaine 0.2%-0.5% 10-50mg + fentanyl 20-25mcg • Done in a seated position→patient is then placed supine • Top up dose of 1-1.5ml of epidural anesthetic is used for each additional segmental block needed. Advantages: 1) High risk patients are exposed to a gentler sympathetic block 2) Ideal for a "walking" epidural

33. General anesthesia in eclamptic pt. • Careful preanesthetic evaluation to be done • Aspiration prophylaxis to be given • Secure an i.v line along with CVP line, PAC optional • Small endotracheal tubes ( 6 and 6.5mm) should be ready • Dificult airway cart should be ready • All monitors to be attached • Start preoxygenation with100% oxygen via well fitting mask for 3-5 minutes • Exaggerated CVS response should be pretreated with either lignocaine or beta blockers • Induces anesthesia with : inj. Thiopentone 4-5mg/kg inj Sch 1-1.5mg/kg RSI #If pt. is on MgSo4therapy, the usual fasciculation following Sch may not occur and it may take 60 sec.

34. General anesthesia in eclamptic pt. • Maintain anesthesia with 50% N2o+50% O2 +0.5% isoflurane until delivery of neonate, with inj. Vecuronium #Neuromuscular monitoring to be done and dosage of NDMR to be titrated accordingly • Extubation: Should be done after 24-48 hrs later in view of- Postpartum seizure Cerebral edema Aspiration pneumonia Hypertensive crisis Pulmonary edema/ARDS DIC, HELLP syndrome Persistent oliguria

35. ICU MANAGEMENT IN ECLAMPSIA • Controlled of ventilation for atleast 24 hours • Weaning after 24 hrs • Inj mannitol infusion 0.5-1gm/kg for 24 hours • MgSo4 to be continued @ 1gm/hr • Inj Furosemide only if signs of pulm. Edema + • Anti H.T to be continued • Maintain strict fluid balance • Monitor electrolytes levels • Serial ABG to be done

36. Summary • Pathogenesis of eclampsia remains unknown • No reliable signs to predict development of eclampsia in women with preeclampsia • Prophylactic MgSO4 effective in preventing eclampsia developing in labor or immediate postpartum with diagnosed preeclampsia • Pregnancy complicated by eclampsia require well-formulated management plan

37. References • Obstetric Anesthesia, David H. Chestnut, 3rd ed. • Shnider and Levinson,s Anesthesia for Obstetrics • Miller’s Anaesthesia, 6th ed • Obstetric Anaesthesia, Sunanda Gupta • Anesthesia and Co-Existing Disease, Stolting Anaesthesia, 5th ed. • Yao & Artusio,s Anesthesiology, 6th ed. • D.C Dutta, 5th ed. • Principal and practice of critical care, PK VERMA

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