Presentation on theme: "Anaesthetic Implications and Management in Preeclampsia & Eclampsia Dr. Shilpa Agarwal Moderator: Dr. JP Sharma"— Presentation transcript:
Anaesthetic Implications and Management in Preeclampsia & Eclampsia Dr. Shilpa Agarwal Moderator: Dr. JP Sharma University College of Medical Sciences & GTB Hospital, Delhi
Contents Classification of hypertensive disorders of pregnancy Diagnosis of preeclampsia Risk factors Obstetric and Anaesthetic management Complications of preeclampsia Diagnosis and risk factors of Eclampsia Obstetric and Anaesthetic management in Eclampsia Complications of Eclampsia
Introduction Hypertensive disorders complicate nearly 5-10% of all pregnancies Deadly triad with infection and haemorrhage In developed countries, 16% of maternal deaths due to hypertensive disorders Preeclampsia – a multifactorial, multi-system hypertensive disorder of pregnancy,is most dangerous etiology remains unknown evidence-based management
History YearMilestones 1903 Chesley-Preeclampsia word included in books 1961 Chesley-Preeclampsia-eclampsia restricted to obstetric definition Eastman and Hellmann -Toxemia of pregnancy -Diagnostic criteria of preeclampsia: hypertension, proteinuria, edema after 24 weeks 1976 Pritchard and Mc Donald -Hypertensive disorders of pregnancy -Diagnostic criteria of preeclampsia: hypertension, proteinuria, edema after 20 weeks 1988 Hibbard-Under classification Hypertensive disorders of pregnancy, preeclampsia grouped into Pregnancy induced Hypertension -Classified into mild-moderate and severe preeclampsia
Classification In 2000, National High Blood Pressure Education Program classified hypertensive disorders complicating pregnancy as: Gestational hypertension Preclampsia- eclampsia chronic hypertension chronic hypertension with superimposed preeclampsia
Gestational Hypertension Blood Pressure ≥ 140/90 on two or more occasions - in a previously normotensive patient - after 20 weeks gestation - without proteinuria - returning to normal 12 weeks after delivery Almost half of these develop preeclampsia syndrome
Chronic Hypertension Blood Pressure ≥ 140/90 before 20 weeks of gestation Or Persistence of hypertension beyond 12 weeks after delivery.
Preeclampsia superimposed on Chronic Hypertension New-onset proteinuria ≥ 300 mg/24 hours in hypertensive women but no proteinuria before 20 weeks’ gestation A sudden increase in proteinuria or blood pressure or platelet count <1 lakh/mm 3 in women with hypertension and proteinuria before 20 weeks’ gestation More adverse outcome than preeclampsia alone
Preeclampsia New onset of hypertension & proteinuria in a previously normotensive woman – after 20 weeks of gestation – Returning to normal after 12 weeks of pregnancy. Edema not a part of diagnosis now. A retrospective diagnosis Eclampsia : new onset of seizures or unexplained coma during pregnancy or postpartum period in patients with pre-existing preeclampsia and without pre-existing neurological disorder.
Epidemiology Preeclampsia complicates nearly 6% - 10% of all pregnancies. maternal ICU admission Leading cause of preterm delivery-NICU Birth of LBW babies- economic, social and medical burden Leading cause of maternal and fetal morbidity and mortality.
Classification of Preeclampsia Mild PESevere PE Blood pressure>140/90>160/110 Proteinuria On 2 occasions, >4hrs apart >0.3gm/ 24 hrs Dip stic > 1+ >5gm/24 hrs Dipstic > 3+ S. creatininenormalelevated Pulmonary edema_+ oliguria_+ IUGR_+ headache_+ Visual disturbance_+ Epigastric pain_+ HELLP syndrome_+
Risk Factors Preconception - Partner related Nulliparity limited exposure to paternal sperms Partner who fathered a preeclamptic pregnancy in another women -Non partner related History of Preeclampsia in previous pregnancy Advanced maternal age Family history of Preeclampsia History of placental abruptio, IUGR, fetal death Non hispanic black race
3. GENETIC Early onsetLate onset onset< 34 wks POG> 34 wks POG frequency20%80% Association with IUGRHighnegligible Familial componentyesno Placental morphologyabnormalnormal etiologyplacentalmaternal Risk factosFamily historyDM, HTN, Maternal age, ↑BMI, CVS disorder Risk of adverse outcomehighnegligible Family history of pre eclampsia: genetic origin Mutations in Complement Regulatory Protein gene Genes assoc.: MTHFR, F5 leiden, AGT, HLA, NOS3, F2(prothrombin), ACE
4. IMMUNOLOGIC Exposure to sperms of different partner long term exposure to paternal antigen in sperms of same partner- protective activated auto antibodies to angiotensin receptor-1 AA- AT1 activate AT1 receptors increased sensitivity to angiotensins hypertension
Haematology Hemoconcentration (pts with anemia may appear to have normal hematocrit) Thombocytopaenia most common Platelet count correlates with disease severity and incidence of abruptio placentae DIC due to activation of coagulation cascade overconsumption of coagulants and platelets spontaneous haemorrhage.
Prediction of Preeclampsia No screening test is really helpful Various screening methods are: Diastolic notch at 24weeks by doppler ultrasonography Absence or reversal of end diastolic flow Average mean arterial pressure ≥ 90 mmHg in second trimester Angiotensin infusion test: angiotensin infusion required to raise the blood pressure >20 mm Hg from baseline Roll over test: rise in blood pressure >20 mmHg from baseline on turning supine at weeks gestation is positive.
Prevention Regular Antenatal checkup: rapid gain in weight rising blood pressure edema proteinuria/deranged liver or renal profile Low dose Aspirin in High risk group: ↑PGs and↓TXA2 Calcium supplementation: no effects unless women are calcium deficient Antioxidants- Vitamin C and E Nutritional supplementation: zinc, magnesium, fish oil, low salt diet
Obstetrics management 1. Maternal evaluation : Hemoglobin and hematocrit platelet count : decreased, if < 1 lakh coagulation profile LFTs : indicated in all patients KFTs : raised (S.urea creatinine is decresaed in Normal pregnancy) Urine Routine : proteinuria
Obs. Manag contd.. 3. Treatment of Acute Hypertension: Goal : to prevent adverse maternal sequalae Aim : to keep DBP below 100 mm Hg and to lower MAP not >15-25%
Anti Hypertensive Drugs DRUGSMOASIDE EFFECTSC/I & PREVENTION Methyldopa 250mg-1g tds or mg iv Central and pripheral anti adrenergic action Maternal-postural hypotension, hemolytic anemia, sodium retention, excessive sedation Fetal-intestinal ileus Hepatic disorders, psychic pts., CCF Labetalol Oral-100mg tds till 800mg/d Iv- 20 mg till desired effect (max. 220mg) Alpha + beta blockerMaternal-tachycardia, hypotension Fetal-bradycardia, hypotension Hepatic disorders Hydralazine Oral-100mg/d in 4 divided doses Peripheral vasodilationMaternal-hypotension, tachycardia, arrythmia, palpitations, lupus like syndrome Fetal- safe Neonate- thrombocytopenia Causes sodium retention so use diuretic
Anti Hypertensives contd.. DRUGSMOASIDE EFFECTSC/I & PREVENTION Nifedipine Oral: 5-10mg tds Arteriolar vasodilationFlushing, hypotension, tachycardia, inhibition of labor With MgSO4 and NMBs Nitroprusside mcg/kg/min Direct vasodilatorMaternal- nausea, vomitting, severe hypotension Fetal- cyanide toxicity Bed rest Avoid Diuretics, ACE inhibitors, ARBs Avoid uterotonics
Obs Manag contd.. 4. Seizure Prophylaxis Routinely used in severe PE Magnesium sulphate: most commonly used Initiated with onset of labor till 24h postpsrtum For caesarean, started 2hrs before the section till 12hrs postpartum
Recommended regime for MgSO 4 – Zuspan or sibai regime : 4-6 gm i.v over 15 min f/b infusion of 1-2 gm/hr – Pritchard regime : 4 gm i.v over 3-5min f/b 5 gm in each buttock with maintenance of 5 gm i.m in alternate buttock 4 hrly
Side effects of MgSO 4 Maternal : flushing, perspiration, headache, muscle weakness, pulmonary edema Neonatal: lethargy, hypotonia, respiratory depression
Management of MgSO 4 Toxicity Stop infusion Intravenous Calcium 10 ml 10% over 10 minutes Endotracheal intubation in respiratory depression
Anaesthetic implications during MgSO 4 therapy oMgSO 4 potentiate and prolong the action of both depolarizing non-depolarizing muscle relaxants oAt higher doses Mg 2+ rapidly crosses the placental barrier, has been found to significantly ↓ FHR variability oShould be given cautiously with Ca 2+ as may antagonize the anticonvulsant effect of MgSO 4 oAlso be cautious in patients with renal impairment oMay ↑ the possibility of hypotension during regional block
Obs. Manag. Contd.. 5. Delivery The only definitive treatment Preeclamptic patients divided into 3 categories A- Preeclampsia features fully subside B- partial control, but BP maintains a steady high level C- persistently increasing BP to severe level or addition of other features
Management: Gp A: can wait till spontaneous onset of labor don’t exceed Expected Date of Delivery Gp B: >37wk terminate w/o delay <37wk, expectant management at least till 34wks Gp C: terminate irrespective of POG, start seizure prophylaxis and steroids if<34wks
Pre anaesthetic Evaluation 1.Airway 2. Haemodynamic monitoring : blood pressure, ECG, Pulse oxymetry 3. Fluid status: volume depleted patients higher risk of hypotension with induction of anaesthesia 4. BP control 5. Coagulation status
Invasive Haemodynamic monitoring Invasive central blood pressure monitoring not routinely indicated Does not improve patient outcome Indications: -oliguria patients -pulmonary edema -poorly controlled maternal blood pressure - massive hemorrhage -frequent arterial blood gas measurements Poor correlation between central venous and pulmonary capillary wedge pressure
Anesthetic Goals of Labor Analgesia in Preeclampsia To establish & maintain hemodynamic stability (control hypertension & avoid hypotension) To provide excellent labor analgesia To prevent complications of preeclampsia – Pulmonary edema – Eclampsia – Intracerebral haemorrhage – Renal failure To be able to rapidly provide anesthesia for Caesarean Section
Analgesia For Labor & delivery Neuraxial analgesia: Lumbar Epidural- gradual onset of sympathetic blockade cardiovascular stability ↓ stress response maintains uteroplacental circulation avoids neonatal depression extended analgesia if cesarean required excellent post op analgesia
Neuraxial analgesia contd.. Combined Spinal Epidural Analgesia- advantages of both Spinal - rapidity requires only small dose of LA ↑vasopressor response-better control of hypotension disadvantage: immediate verification of catheter function not possible
Anaesthesia for Caesarean Epidural anaesthesia Spinal anaesthesia: advantage: rapidity requires only small dose of LA ↑vasopressor response-better control of hypotension Combined Spinal Epidural Anaesthesia – Indications: Patient preference Contraindications to general anaesthesia Hemodynamically stable patient
Anaesthesia for caesarean contd.. General anaesthesia: Indications - coagulopathy -sustained fetal bradycardia with reassuring maternal airway - severe ongoing maternal hemorrhage - contraindications to neuraxial technique
Concerns with neuraxial anaesthesia Adequate hydration: - risk of pulmonary edema -Lower concentration of local anesthetics: hypotension less common Treatment of hypotension if any: - small doses of vasopressors Epinephrine containing test dose should be avoided Coagulation status -mild preeclampsia-: hypercoagulable -severe preeclampsia-: hypocoagulable -bleeding time poor indicator of platelet function
Platelets and neuraxial anaesthesia platelets >1lakh/mm 3, coagulation profile not indicated Platelets <1 lakh/mm 3 -clinical evidence of bleeding -platelet trend-Every 6hourly if stable, every 1-3hrly if declining -coagulation profile: PT/PTTK/INR -quality of platelets -risk vs benefit Platelets <50,000: contraindication
Platelets contd.. - remove epidural catheter only when platelet count returns normal (at least /mm 3 ) -emergency imaging studies and neurologic evaluation if epidural hematoma suspected -In various studies, it has been found that low dose aspirin doesn’t significantly affect bleeding time, neuraxial analgesia can be given safely without any complication
Coagulopathy and Neuraxial Anaesthesia ASRA guidelines Frank coagulopathy is an absolute contraindication Subcutaneous (minidose) heparin thromboprophylaxis: not a contraindication, however – Assess platelet count before needle placement and removal of catheter, if > 4days heparin therapy – Stop heparin 4-5 days prior to needle placement With Low Molecular Weight Heparin: - needle placement and catheter removal hours after last dose, at higher doses after 24h - first post operative dose after 6-8 hours -repeat dose after at least 2hours of catheter removal
Hazards of General Anaesthesia 1.Difficult intubation- -smaller size tube -difficult airway cart ready 2. Exaggerated and prolonged hypertensive response to laryngoscopy and intubation: -risk of intracranial hemorrhage. -labetalol(5-10 mg), local anesthetics, esmolol( 2mg/kg ), nitroglycerine(200mcg/ml), nitroprusside 0.5mcg/kg/min, remifentanyl (1mcg/kg) used before intubation and extubation
Hazards contd.. 3.MgSO 4 with neuromuscular blockers, calcium channel blockers, uterotonics and uterine relaxants 4. Uterotonics avoided: risk of acute hypertension and eclampsia
General Anaesthesia administration in severe Preeclampsia Place a radial canula for continuous BP monitoring i.v line secured Arrange smaller size endotracheal tubes Antacids and perinorm given 30 minutes before 100% oxygen for 3 min. Labetalol 10 mg iv bolus and titrate to effect before induction, while monitoring fetal heart rate Rapid Sequence Induction Labetalol 5-10 mg before extubation Give opioids or BZDS after delivery.
Post op concerns Post op analgesia : intravenous opioids, neuraxial opioids concern : monitor for respiratory depression Post partum management: risk of pulmonary edema, sustained hypertension, stroke, Venous thromboembolism, seizures, HELLP, postpartum hemorrhage.
Complications CVA: main leading cause of death in pts with PE absolute risk is low reversible cerebral edema is m/c Pulmonary edema, pleural effusion, ARDS: head end elevation oxygen therapy restrict fluids diuretics mechanical ventilation laryngeal edema Placental abruptio
Complications contd.. Renal failure: oliguria most common haemodynamic monitoring diuretics Liver: Subcapsular liver hematoma: avoid trauma to liver, HELLP Syndrome, hepatic rupture with shock : surgical emergency DIC: treat the cause platelets/Fresh Frozen Plasma/cryoprecipitate Eclampsia Maternal death
HELLP contd.. Ultimate goal: – >34 wks gestation deliver – <34wks expectant management if stable maternal and fetal conditions Platelet transfusion if: <40,000/mm 3 before cesarean <20,000/mm 3 before delivery
ECLAMPSIA Is the new onset of seizures or unexplained coma during pregnancy or postpartum period in patients with pre-existing PE and without pre-existing neurological disorder.
Epidemiology per 10,000 pregnancies Decreasing incidence with time Antepartum(50%): mostly in third trimester Intrapartum(30%): Postpartum(20%): usually within 48hours, fits beyond 7days generally rules out eclampsia
Risk factors Maternal age less than 20 years Multigravida Molar pregnancy Triploidy Pre-existing hypertension or renal disease Previous severe Preeclampsia or Eclampsia Nonimmune hydrops fetalis Systemic Lupus Erythematosus
Clinical features Eclamptic convulsions are epileptiform and consist of four stages Premonitory stage: twitching of muscles of face, tongue, limbs and eye. Eyeballs rolled or turned to one side, 30s Tonic stage: opisthotonus, limbs flexed, hands clenched, 30s Clonic stage: 1-4 min, frothing, tongue bite, stertorous breathing Stage of coma: variable period.
Physical Examination Sustained rise in blood pressure Tachycardia, Tachyponea Rales Mental status changes Hypereflexia Clonus Papilloedema Oliguria or anuria Right upper quadrant or epigastric abdominal tenderness Generalized edema Small fundal height for the estimated gestational age
Pathogenesis Loss of normal cerebral auto regulatory mechanisms cerebral hyperperfusion Edema & ↓cerebral blood flow
Differential Diagnosis meningitis encephalitis space occupying lesion electrolyte disturbance vasculitis amniotic fluid embolism medications organ failure stroke
Prediction and Prevention Early detection and judicious treatment with termination of pregnancy in Preeclamptic patients Adequate sedation, Anti hypertensives and prophylactic Anticonvulsant in peripartum period Observe for hrs postpartum
Management of Eclampsia 1.Prevention of seizures 2.Control of seizures
Prevention of convulsions MgSO 4 therapy: DOC for prophylaxis of eclamptic convulsions M.O.A: blocks Ca 2+ ion influx into neurons leading to cerebral vasodilatation Other actions: -lowers endothelin-1 levels - ↑ production of PG I 2 - tocolytic action - attenuates the release of Ach and sensitivity to Ach at myoneuronal junction
Control of seizures -turn patient head to one side, -apply jaw thrust if airway compromised -nasopharyngeal airway -Adequate oxygenation - ensure adequate breathing, bag and mask ventilation can be done - secure an i.v line - Drugs- Antiepileptics Antihypertensives - Delivery
Anticonvulsants DrugsMechanism of actionContraindicationsSide effects MgSO4 Zuspan or sibai regime: 4-6g iv over 15 min f/b infusion of 1-2g/h Pitchard regime: 4g i.v over 3-5min f/b 5g in each buttock with maintenance of 5g i,.m in alternate buttock 4hrly Competitive inhibition of calcium ions at motor end plate or cell membrane, ↓ Ach release & sensitivity Patients with MG and impaired renal function, heart block, digitalis Maternal : flushing Perspiration, headache, muscle weakness, pulmonary edema Neonatal: lethargy, hypotonia, respiratory depression Diazepam mg I.V f/b 40 mg diazepam in 500ml normal saline at 30 drops per minute Cerebral muscle relaxant and anticonvulsants Maternal : hypotension Fetal : respiratory depression, may last even 3 weeks after delivery Phenytoin 10 mg/kg IV at not more than 50 mg/min f/b 2 hrs later by 5 mg/kg for 12 hrs, thereafter 200mg orally till 48hours Centrally acting anticonvulsants Maternal: hypotension, cardiac arrythmias, phlebitis, hyperglycemia, respiratory arrest, cardiac arrest, bradycardia Fetal: Fetal hydantoin syndrome
Refractory seizures Thiopentone sodium 0.5 g in 20 ml of 5% Dextrose intravenously slowly Propofol infusion Midazolam infusion if fails then General Anaesthesia Seizures still not controlled then termination of pregnancy
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 labor Recurrent seizures
Anaesthetic Management 1.Assess seizure control and neurologic function 2.Fluids : ml/hr avoid cerebral edema, CVP guided fluid therapy 3.BP control : appropriate anti hypertensives 4.Monitoring :Pulse oxymeter, ECG, Fetal Heart Rate, Urine output, NM monitoring, Mg monitoring, 5.Lab inv: CBC, Bld sugar, Bld urea, S.creatinine, S.uric acid level with S.E, LFTs, Coagulation profile, 24 hrs specimen for protein 6.Choice of anaesthesia: GA preferred with thiopentone or propofol (both decreases ICP) 7.Avoid hypo or hyperglycaemia, hypoxia, hyperthermia 8.Peripartum : manage for shock, sepsis, psychosis thrombocytopenia, DIC, coagulopathy
Choice of Anaesthesia in Eclampsia Neuraxial: - indications - seizures controlled - no coagulopathy - patient cooperative GA: - Indications -seizures not controlled -coagulopathy -reassuring airway -uncooperative patients
General anesthesia in eclamptic pt. oCareful preanesthetic evaluation to be done oAspiration prophylaxis to be given oSecure an i.v line oSmall endotracheal tubes ( 6 and 6.5mm) should be ready oDifficult airway cart should be ready oAll monitors to be attached oStart preoxygenation with100% oxygen via well fitting mask for 3-5 minutes oExaggerated CVS response should be pretreated with either lignocaine or beta blockers oInduces anesthesia with : inj. Thiopentone 4-5mg/kg inj Sch 1-1.5mg/kg RSI #If pt. is on MgSo 4 therapy, the usual fasciculation following Sch may not occur and it may take 60 sec.
General anesthesia in eclamptic pt. oMaintain anesthesia with 50% N 2 o+50% O % isoflurane until delivery of neonate, with inj. Vecuronium #Neuromuscular monitoring to be done and dosage of NDMR to be titrated accordingly o Extubation: Should be done after hrs later in view of- Postpartum seizure, Cerebral edema, Aspiration pneumonia, Hypertensive crisis, Pulmonary edema, ARDS DIC, HELLP syndrome Persistent oliguria
Summary Preeclampsia is a multisystem disorder. Management is supportive, delivery is the only definitive. Preeclampsia patients: High risk for difficult intubation. Hypertensive response to laryngoscopy intracranial hemorrhage. Spinal Anaesthesia not contraindicated in severe Preeclampsia Eclampsia can be prevented by prophylactic MgSO4 therapy Eclamptic patients should be monitored for at least 24 hrs post partum.
References Chestnut’s Obstetric Anaesthesia: Principles and Practice, “Hypertensive disorders” 4 th Ed, Ch 45, Miller’s Anaesthesia, “Anaesthesia for Obstetrics” 7 th Ed,Ch 69, Wylie and Churchill Davidson’s A Practice of Anaesthesia, “Obstetric Anaesthesia” 7 th Ed, Ch57, 934 Morgan’s Clinical Anaesthesiology, “Obstetric Anaesthesia” 4 th Ed, Ch 43, Textbook of Obstetrics, D.C. Dutta, “Hypertensive Disorders in Pregnancy” 6 th Ed, Ch 17, William obstetrics, “Pregnancy Hypertension” Ch34, Bell M.J, BSN, RN, A Historical Overview of Preeclampsia- Eclampsia J Obstet Gynecol Neonatal Nurs September ; 39(5): 510–518