Presentation on theme: "Anaesthetic Implications and Management in Preeclampsia & Eclampsia"— Presentation transcript:
1 Anaesthetic Implications and Management in Preeclampsia & Eclampsia Dr. Shilpa AgarwalModerator: Dr. JP SharmaUniversity College of Medical Sciences & GTB Hospital, Delhi
2 Contents Classification of hypertensive disorders of pregnancy Diagnosis of preeclampsiaRisk factorsObstetric and Anaesthetic managementComplications of preeclampsiaDiagnosis and risk factors of EclampsiaObstetric and Anaesthetic management in EclampsiaComplications of Eclampsia
3 IntroductionHypertensive disorders complicate nearly 5-10% of all pregnanciesDeadly triad with infection and haemorrhageIn developed countries, 16% of maternal deaths due to hypertensive disordersPreeclampsia – a multifactorial, multi-system hypertensive disorder of pregnancy ,is most dangerousetiology remains unknownevidence-based management
4 History 1903 Chesley -Preeclampsia word included in books 1961 Chesley YearMilestones1903 Chesley-Preeclampsia word included in books1961 Chesley-Preeclampsia-eclampsia restricted to obstetric definition.1966 Eastman and Hellmann-Toxemia of pregnancy-Diagnostic criteria of preeclampsia: hypertension, proteinuria, edema after 24 weeks1976 Pritchard and Mc Donald-Hypertensive disorders of pregnancy-Diagnostic criteria of preeclampsia: hypertension, proteinuria, edema after 20 weeks1988 Hibbard-Under classification Hypertensive disorders of pregnancy, preeclampsia grouped into Pregnancy induced Hypertension-Classified into mild-moderate and severe preeclampsia
5 ClassificationIn 2000, National High Blood Pressure Education Program classified hypertensive disorders complicating pregnancy as:Gestational hypertensionPreclampsia- eclampsiachronic hypertensionchronic hypertension with superimposed preeclampsia
6 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 deliveryAlmost half of these develop preeclampsia syndrome
7 Chronic HypertensionBlood Pressure ≥ 140/90 before 20 weeks of gestationOrPersistence of hypertension beyond 12 weeks after delivery.
8 Preeclampsia superimposed on Chronic Hypertension New-onset proteinuria ≥ 300 mg/24 hours in hypertensive women but no proteinuria before 20 weeks’ gestationA sudden increase in proteinuria or blood pressure or platelet count <1 lakh/mm3 in women with hypertension and proteinuria before 20 weeks’ gestationMore adverse outcome than preeclampsia alone
9 PreeclampsiaNew onset of hypertension & proteinuria in a previously normotensive womanafter 20 weeks of gestationReturning to normal after 12 weeks of pregnancy.Edema not a part of diagnosis now.A retrospective diagnosisEclampsia : new onset of seizures or unexplained coma during pregnancy or postpartum period in patients with pre-existing preeclampsia and without pre-existing neurological disorder.
11 EpidemiologyPreeclampsia complicates nearly 6% - 10% of all pregnancies.maternal ICU admissionLeading cause of preterm delivery-NICUBirth of LBW babies- economic, social and medical burdenLeading cause of maternal and fetal morbidity and mortality.
13 Risk Factors Preconception - Partner related -Non partner related Nulliparitylimited exposure to paternal spermsPartner who fathered a preeclamptic pregnancy in another women-Non partner relatedHistory of Preeclampsia in previous pregnancyAdvanced maternal ageFamily history of PreeclampsiaHistory of placental abruptio, IUGR, fetal deathNon hispanic black race
14 Risk factors contd.. -Maternal disease related -Behaviour- Obesity, BMI>35 doubles the riskHypertensionDiabetesThrombotic vascular diseases-Behaviour-Smoking : preventive-Pregnancy associated-Multiple gestationMolar pregnancy
15 ETIOPATHOGENESIS Exact mechanism unknown, disease of theories. ABNORMAL PLACENTATIONStage1: failure of trophoblastic invasion into myometriumPenetrates only deciduasuperficial placentation ↓placental perfusionstage2 : endothelial damagesystemic manifestations of Preeclampsia
18 3. GENETIC Family history of pre eclampsia: genetic origin Mutations in Complement Regulatory Protein geneGenes assoc.: MTHFR, F5 leiden, AGT, HLA, NOS3, F2(prothrombin), ACEEarly onsetLate onsetonset< 34 wks POG> 34 wks POGfrequency20%80%Association with IUGRHighnegligibleFamilial componentyesnoPlacental morphologyabnormalnormaletiologyplacentalmaternalRisk factosFamily historyDM, HTN, Maternal age, ↑BMI, CVS disorderRisk of adverse outcomehigh
19 4. IMMUNOLOGIC Exposure to sperms of different partner long term exposure to paternal antigen in sperms of same partner- protectiveactivated auto antibodies to angiotensin receptor-1 AA-AT1activate AT1 receptorsincreased sensitivity to angiotensins hypertension
25 CVS Vasospasm and exaggerated responses to catecholamines Increased vascular permeability↓ Colloid Oncotic Pressurehypertensionendorgan ischemiaIntravascular volume deficit
26 Haemat ologyHemoconcentration (pts with anemia may appear to have normal hematocrit)Thombocytopaenia most commonPlatelet count correlates with disease severity and incidence of abruptio placentaeDIC due to activation of coagulation cascadeoverconsumption of coagulants and platelets spontaneous haemorrhage.
30 Prediction of Preeclampsia No screening test is really helpfulVarious screening methods are:Diastolic notch at 24weeks by doppler ultrasonographyAbsence or reversal of end diastolic flowAverage mean arterial pressure ≥ 90 mmHg in second trimesterAngiotensin infusion test: angiotensin infusion required to raise the blood pressure >20 mm Hg from baselineRoll over test: rise in blood pressure >20 mmHg from baseline on turning supine at weeks gestation is positive.
31 Prevention Regular Antenatal checkup: rapid gain in weight rising blood pressureedemaproteinuria/deranged liver or renal profileLow dose Aspirin in High risk group: ↑PGs and↓TXA2Calcium supplementation: no effects unless women are calcium deficientAntioxidants- Vitamin C and ENutritional supplementation: zinc, magnesium, fish oil, low salt diet
33 Obstetrics management 1. Maternal evaluation :Hemoglobin and hematocritplatelet count : decreased, if < 1 lakh coagulation profileLFTs : indicated in all patientsKFTs : raised (S.urea creatinine is decresaed in Normal pregnancy)Urine Routine : proteinuria
34 Obstetrics management contd.. 2. Fetal evaluation:Daily fetal movement countUltrasoundDoppler ultrasound for fetal blood flowVelocimetry
35 Obs. Manag contd.. 3. Treatment of Acute Hypertension: Goal: to prevent adverse maternal sequalaeAim: to keep DBP below 100 mm Hg and to lower MAP not >15-25%
36 Anti Hypertensive Drugs MOASIDE EFFECTSC/I & PREVENTIONMethyldopa 250mg-1g tds or mg ivCentral and pripheral anti adrenergic actionMaternal-postural hypotension, hemolytic anemia, sodium retention, excessive sedationFetal-intestinal ileusHepatic disorders, psychic pts., CCFLabetalolOral-100mg tds till 800mg/dIv- 20 mg till desired effect (max. 220mg)Alpha + beta blockerMaternal-tachycardia, hypotensionFetal-bradycardia, hypotensionHepatic disordersHydralazineOral-100mg/d in 4 divided dosesPeripheral vasodilationMaternal-hypotension, tachycardia, arrythmia, palpitations, lupus like syndromeFetal- safeNeonate- thrombocytopeniaCauses sodium retention so use diureticAce $ avoid
37 Anti Hypertensives contd.. DRUGSMOASIDE EFFECTSC/I & PREVENTIONNifedipineOral: 5-10mg tdsArteriolar vasodilationFlushing, hypotension, tachycardia, inhibition of laborWith MgSO4 and NMBsNitroprussidemcg/kg/minDirect vasodilatorMaternal- nausea, vomitting, severe hypotensionFetal- cyanide toxicityBed restAvoid Diuretics, ACE inhibitors, ARBsAvoid uterotonics
38 Obs Manag contd.. 4. Seizure Prophylaxis Routinely used in severe PE Magnesium sulphate: most commonly usedInitiated with onset of labor till 24h postpsrtumFor caesarean, started 2hrs before the section till 12hrs postpartum
39 Recommended regime for MgSO4 Zuspan or sibai regime: 4-6 gm i.v over 15 min f/b infusion of 1-2 gm/hrPritchard 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
40 Side effects of MgSO4 Maternal : flushing, perspiration, headache, muscle weakness, pulmonary edemaNeonatal: lethargy, hypotonia, respiratorydepression
42 Management of MgSO4 Toxicity Stop infusionIntravenous Calcium 10 ml 10% over 10 minutesEndotracheal intubation in respiratory depression
43 Anaesthetic implications during MgSO4 therapy MgSO4 potentiate and prolong the action of both depolarizing non-depolarizing muscle relaxantsAt higher doses Mg2+ rapidly crosses the placental barrier, has been found to significantly ↓ FHR variabilityShould be given cautiously with Ca2+ as may antagonize the anticonvulsant effect of MgSO4Also be cautious in patients with renal impairmentMay ↑ the possibility of hypotension during regional block
44 Obs. Manag. Contd.. 5. Delivery The only definitive treatment Preeclamptic patients divided into 3 categoriesA- Preeclampsia features fully subsideB- partial control, but BP maintains a steady high levelC- persistently increasing BP to severe level or addition of other features
45 Gp A: can wait till spontaneous onset of labor Management:Gp A: can wait till spontaneous onset of labordon’t exceed Expected Date of DeliveryGp B: >37wk terminate w/o delay<37wk, expectant management at least till 34wksGp C: terminate irrespective of POG,start seizure prophylaxis andsteroids if<34wks
47 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
48 Invasive Haemodynamic monitoring Invasive central blood pressure monitoring not routinely indicatedDoes not improve patient outcomeIndications:-oliguria patients-pulmonary edema-poorly controlled maternal blood pressure- massive hemorrhage-frequent arterial blood gas measurementsPoor correlation between central venous and pulmonary capillary wedge pressure
49 Anesthetic Goals of Labor Analgesia in Preeclampsia To establish & maintain hemodynamic stability (control hypertension & avoid hypotension)To provide excellent labor analgesiaTo prevent complications of preeclampsiaPulmonary edemaEclampsiaIntracerebral haemorrhageRenal failureTo be able to rapidly provide anesthesia for Caesarean Section
50 Analgesia For Labor & delivery Neuraxial analgesia:Lumbar Epidural-gradual onset of sympathetic blockadecardiovascular stability↓ stress responsemaintains uteroplacental circulationavoids neonatal depressionextended analgesia if cesarean requiredexcellent post op analgesia
51 Neuraxial analgesia contd.. Combined Spinal Epidural Analgesia-advantages of bothSpinal - rapidityrequires only small dose of LA↑vasopressor response-better control of hypotensiondisadvantage: immediate verification of catheter function not possible
52 Anaesthesia for Caesarean Epidural anaesthesiaSpinal anaesthesia:advantage: rapidityrequires only small dose of LA↑vasopressor response-better control of hypotensionCombined Spinal Epidural AnaesthesiaIndications:Patient preferenceContraindications to general anaesthesiaHemodynamically stable patient
53 Anaesthesia for caesarean contd.. General anaesthesia:Indications- coagulopathy-sustained fetal bradycardia with reassuring maternal airway- severe ongoing maternal hemorrhage- contraindications to neuraxial technique
54 Concerns with neuraxial anaesthesia Adequate hydration:- risk of pulmonary edema-Lower concentration of local anesthetics: hypotension less commonTreatment of hypotension if any:- small doses of vasopressorsEpinephrine containing test dose should be avoidedCoagulation status-mild preeclampsia-: hypercoagulable-severe preeclampsia-: hypocoagulable-bleeding time poor indicator of platelet function
55 Platelets and neuraxial anaesthesia platelets >1lakh/mm3, coagulation profile not indicatedPlatelets <1 lakh/mm3-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 benefitPlatelets <50,000: contraindication
56 Platelets contd..- remove epidural catheter only when platelet count returns normal (at least /mm3)emergency imaging studies and neurologic evaluation if epidural hematoma suspectedIn 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
57 Coagulopathy and Neuraxial Anaesthesia ASRA guidelinesFrank coagulopathy is an absolute contraindicationSubcutaneous (minidose) heparin thromboprophylaxis: not a contraindication, howeverAssess platelet count before needle placement and removal of catheter, if > 4days heparin therapyStop heparin 4-5 days prior to needle placementWith 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
58 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
59 Hazards contd..3.MgSO4 with neuromuscular blockers, calcium channel blockers, uterotonics and uterine relaxants4. Uterotonics avoided: risk of acute hypertension and eclampsia
60 General Anaesthesia administration in severe Preeclampsia Place a radial canula for continuous BP monitoringi.v line securedArrange smaller size endotracheal tubesAntacids and perinorm given 30 minutes before100% oxygen for 3 min.Labetalol 10 mg iv bolus and titrate to effect before induction, while monitoring fetal heart rateRapid Sequence InductionLabetalol 5-10 mg before extubationGive opioids or BZDS after delivery.
61 Post op concerns Post op analgesia: Post partum management: intravenous opioids, neuraxial opioidsconcern : monitor for respiratory depressionPost partum management:risk of pulmonary edema, sustained hypertension, stroke, Venous thromboembolism, seizures, HELLP, postpartum hemorrhage.
62 Complications CVA: main leading cause of death in pts with PE absolute risk is lowreversible cerebral edema is m/cPulmonary edema, pleural effusion, ARDS:head end elevationoxygen therapyrestrict fluidsdiureticsmechanical ventilationlaryngeal edemaPlacental abruptio
63 Complications contd.. Renal failure: oliguria most common haemodynamic monitoringdiureticsLiver:Subcapsular liver hematoma: avoid trauma to liver,HELLP Syndrome,hepatic rupture with shock : surgical emergencyDIC: treat the causeplatelets/Fresh Frozen Plasma/cryoprecipitateEclampsiaMaternal death
68 ECLAMPSIAIs 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.
69 Epidemiology 0.1- 5.5 per 10,000 pregnancies Decreasing incidence with timeAntepartum(50%): mostly in third trimesterIntrapartum(30%):Postpartum(20%): usually within 48hours, fits beyond 7days generally rules out eclampsia
70 Risk factors Maternal age less than 20 years Multigravida Molar pregnancyTriploidyPre-existing hypertension or renal diseasePrevious severe Preeclampsia or EclampsiaNonimmune hydrops fetalisSystemic Lupus Erythematosus
71 Clinical featuresEclamptic convulsions are epileptiform and consist of four stagesPremonitory stage: twitching of muscles of face, tongue, limbs and eye. Eyeballs rolled or turned to one side, 30sTonic stage: opisthotonus, limbs flexed, hands clenched, 30sClonic stage: 1-4 min, frothing, tongue bite, stertorous breathingStage of coma: variable period.
72 Physical Examination Sustained rise in blood pressure Tachycardia, TachyponeaRalesMental status changesHypereflexiaClonusPapilloedemaOliguria or anuriaRight upper quadrant or epigastric abdominal tendernessGeneralized edemaSmall fundal height for the estimated gestational age
73 Pathogenesis Loss of normal cerebral auto regulatory mechanisms cerebral hyperperfusionEdema & ↓cerebral blood flow
75 Prediction and Prevention Early detection and judicious treatment with termination of pregnancy in Preeclamptic patientsAdequate sedation, Anti hypertensives and prophylactic Anticonvulsant in peripartum periodObserve for hrs postpartum
76 Management of Eclampsia Prevention of seizuresControl of seizures
77 Prevention of convulsions MgSO4 therapy:DOC for prophylaxis of eclamptic convulsionsM.O.A:blocks Ca2+ ion influx into neuronsleading to cerebral vasodilatationOther actions: -lowers endothelin-1 levels- ↑ production of PG I2- tocolytic action- attenuates the release of Ach and sensitivity to Ach at myoneuronal junction
78 Control of seizures -turn patient head to one side, -apply jaw thrust if airway compromisednasopharyngeal airwayAdequate oxygenation- ensure adequate breathing , bag and mask ventilation can be done- secure an i.v line- Drugs- AntiepilepticsAntihypertensives- Delivery
79 Anticonvulsants Drugs Mechanism of action Contraindications Side effectsMgSO4Zuspan or sibai regime: 4-6g iv over 15 min f/b infusion of 1-2g/hPitchard regime: 4g i.v over 3-5min f/b 5g in each buttock with maintenance of 5g i,.m in alternate buttock 4hrlyCompetitive inhibition of calcium ions at motor end plate or cell membrane, ↓ Ach release & sensitivityPatients with MG and impaired renal function, heart block, digitalisMaternal : flushingPerspiration, headache, muscle weakness, pulmonary edemaNeonatal: lethargy, hypotonia, respiratory depressionDiazepam10-20 mg I.V f/b 40 mg diazepam in 500ml normal saline at 30 drops per minuteCerebral muscle relaxant and anticonvulsantsMaternal : hypotensionFetal : respiratory depression, may last even 3 weeks after deliveryPhenytoin10 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 48hoursCentrally acting anticonvulsantsMaternal: hypotension, cardiac arrythmias, phlebitis, hyperglycemia, respiratory arrest, cardiac arrest, bradycardiaFetal: Fetal hydantoin syndrome
80 Refractory seizuresThiopentone sodium 0.5 g in 20 ml of 5% Dextrose intravenously slowlyPropofol infusionMidazolam infusionif fails then General AnaesthesiaSeizures still not controlled then termination of pregnancy
81 Delivery in EclampsiaUnless contraindicated: Eclamptic women should undergo normal vaginal deliveryIndications for cesarean section -Fetal distressPlacental abruptionExtreme prematurityUnfavorable cervixFailed induction of laborRecurrent seizures
82 Anaesthetic Management Assess seizure control and neurologic functionFluids : ml/hravoid cerebral edema,CVP guided fluid therapyBP control : appropriate anti hypertensivesMonitoring :Pulse oxymeter , ECG, Fetal Heart Rate, Urine output, NM monitoring, Mg monitoring,Lab inv: CBC, Bld sugar, Bld urea, S.creatinine, S.uric acid level with S.E, LFTs, Coagulation profile, 24 hrs specimen for proteinChoice of anaesthesia: GA preferred with thiopentone or propofol (both decreases ICP)Avoid hypo or hyperglycaemia, hypoxia, hyperthermiaPeripartum : manage for shock, sepsis, psychosis thrombocytopenia, DIC, coagulopathy
83 Choice of Anaesthesia in Eclampsia Neuraxial: -indications seizures controlled- no coagulopathy- patient cooperativeGA: -Indications seizures not controlled-coagulopathy-reassuring airway-uncooperative patients
84 General anesthesia in eclamptic pt. Careful preanesthetic evaluation to be doneAspiration prophylaxis to be givenSecure an i.v lineSmall endotracheal tubes ( 6 and 6.5mm) should be readyDifficult airway cart should be readyAll monitors to be attachedStart preoxygenation with100% oxygen via well fitting mask for 3-5 minutesExaggerated CVS response should be pretreated with either lignocaine or beta blockersInduces anesthesia with : inj. Thiopentone 4-5mg/kginj Sch 1-1.5mg/kg RSI#If pt. is on MgSo4 therapy, the usual fasciculation following Sch may not occur and it may take 60 sec.
85 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 accordinglyExtubation: Should be done after hrs later in view of-Postpartum seizure, Cerebral edema, Aspiration pneumonia, Hypertensive crisis, Pulmonary edema, ARDSDIC, HELLP syndromePersistent oliguria
86 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 PreeclampsiaEclampsia can be prevented by prophylactic MgSO4 therapyEclamptic patients should be monitored for at least 24 hrs post partum.
87 ReferencesChestnut’s Obstetric Anaesthesia: Principles and Practice, “Hypertensive disorders” 4th Ed, Ch 45,Miller’s Anaesthesia, “Anaesthesia for Obstetrics” 7th Ed,Ch 69,Wylie and Churchill Davidson’s A Practice of Anaesthesia, “Obstetric Anaesthesia” 7th Ed, Ch57, 934Morgan’s Clinical Anaesthesiology, “Obstetric Anaesthesia” 4th Ed, Ch 43,Textbook of Obstetrics, D.C. Dutta, “Hypertensive Disorders in Pregnancy” 6th 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