Aetiology of Pre-eclampsia

Hypertensivedisorders inpregnancy

This is a multisystem disorder with implications for both mother and fetus.

It is hypertension in pregnancy of two consecutive blood pressure readings, spaced 6 hours apart, greater than 140/90mmHg and proteinuria of greater than 300mg in 24 hours. It only occurs after the 20th week of gestation (that is, after late 2nd or 3rd trimester), that is in a previously normotensive patient.Definition: Pre-eclampsiaThis rise is compared to booking blood pressure in the 1st trimester

2The development of epileptiform convulsions in the pregnant patient in association with a diagnosis of pre-eclampsiaSeizures are usually grand-mal tonic clonic

Definition: EclampsiaECLAMPSIA IS AN OBSTETRIC EMERGENCYUsually asymptomatic but can manifest in severe disease with:Headache(especially frontal)Visual disturbanceEpigastric or Right upper Quadrant(RUQ) painNausea and VomitingRapid Edema (especially face)

Symptoms of pre-eclampsia4Hypertension (rise of 15mmHg over booking blood pressure)Proteinuria(>300 mg in 24 hours)Facial edemaEpigastric/RUQ tendernessConfusionHyperreflexia( clonus(>3 beats))Uterine tenderness or vaginal bleeding from a placental abruptionFetal growth restriction(esp. 140mmHg on two occasions at least 6 hours apartProteinuria of > 300mg in 24 hours (1+ or greater on dipstick testing)Severe pre-eclampsiaSystolic Blood pressure of >160 mmHg on two consecutive occasions, six hours apartProteinuria >3g in 24 hours (>3+ on dipstick)OliguriaCyanosis as a result of Pulmonary Edema Symptoms of impending eclampsiaFeatures of HELLP syndromeClassification of Pre-eclampsiaSymptoms of impending eclampsia: headache, visual disturbances or epigastric painFeaturs of HELLP: Hamolysis elevated liver enzymes (transaminase of > 10% upper limit of normal Low platelets ( 40 weeks gestationdelivery, magnesium sulfate37 - 39 weeks gestationinducible cervix: delivery, magnesium sulfatecervix not inducible: inpatient or outpatient managementPREECLAMPSIASevere preeclampsia - expectant managementgestational age: not recommended for < 24 weeks or > 34 weeks gestationhospitalization: tertiary care centerantenatal testing: daily PREECLAMPSIASevere preeclampsia - guidelines for expedient deliverymaternal indicationseclampsia, thrombocytopenia, pulmonary edema, acute renal failurepersistent severe headache or visual changeselevated liver enzymes with persistent severe epigastric pain or right upper quadrant tendernesslabor or rupture of membranesvaginal bleeding, abruptio placentaPREECLAMPSIASevere preeclampsia - guidelines for expedient deliveryfetal indicationsrepetitive severe variables or late decelerations biophysical profile < 4 on two occasions 4 hours apartamniotic fluid index < 2 cmintrauterine growth restrictionfetal death> 34 weeks gestationPREECLAMPSIASevere preeclampsia - management protocoladmission to labor and delivery for 24 hoursmagnesium sulfate IV for 24 hoursantihypertensives if diastolic blood pressure > 110 mmHgmeet guidelines for expedited delivery?yes? Delivery

NOTE: SYNTOMETRINE IS CONTRAINDICATEDPREECLAMPSIASevere preeclampsia - management protocolExpedited delivery? no?< 23 weeks: counseling for termination of pregnancy23-32 weeks: steroids, antihypertensive medications, daily maternal and fetal evaluation, delivery at 34 weeks32-33 weeks: amniocentesisimmature fluid - steroids, delivery in 48 hoursPREECLAMPSIAMay be maternal or fetalEclampsia is one of the most detrimental complications and affects both the mother and fetusMost women make a full recovery, however, though small there is a risk of permanent disability or brain damage if convulsions are severe. Around 1 in 50 eclamptic mothers die from the conditionDuring a seizure, unborn babies may suffocate and 1 in 14 may dieComplications of Pre-eclampsiaHELLP Syndrome- combined liver and blood clotting disorderMost likely to occur immediately after delivery but can appear anytime after 20 wks pregnancy or rarely beforePotentially as serious as eclampsia but slightly more commonPotential treatment is delivery of the baby with main danger to baby from premature birth

Complications for the motherCerebral haemorrhage (more commonly stroke)Blood clotting disorder- thrombocytopenia is the most frequent coagulation abnormality but full picture of DIC not usually observedComplications for the motherCerebral haemorrhage, vasospasm and cerebral edema are the underlying pathological changes seen in patients with pre-eclampsia38Organ problems:Acute renal failureCardiac failurePulmonary edemaAdult respiratory distress syndromeHepatic rupture- rarelyComplications for the motherIUGRIncreased perinatal mortality and morbidityComplications of sequale of prematurityComplications for the babyAim:

1- Maintain patent airways and stabilise the patient

2- Stop and Prevent the fits

3- Administer Anti-hypertensives

4- Deliver in the the safest and most expeditious means to the mother Management of ECLAMPSIA Usually unnecessary to try to stop the initial convulsion which usually last about 60-90 secondsIV Diazepam slowly 5mg over 1 minRoll the patient on his left side to avoid maternal injuryManagement of ECLAMPSIA 4. Apply Suction to the secretion from her mouth5. Adequate Oxygen should be maintained by face mask & airways to prevent swallowing of tongue6. Prevent further convulsions by MgSO4 by IV bolus of 4 6 g over 15 min. If convulsion recur further bolus of 2g. (According to Magpie Trial)7. Acidosis should be corrected if necessary by IV NaHCO38. SBP 170 mmHg or more, DBP 110 mmHg is risk factor for CVA so should be lowered by either Nifedipine 10 20 mg SL. Or Hydralazine 5mg followed by infusion.Management of ECLAMPSIA Eclampsia - anticonvulsant therapymagnesium sulfatemechanism of action - smooth muscle relaxation by displacement of calciumdosage - 4-6 g intravenous loading dose, followed by 2 g per hourmay be given intramuscularlyManagement of ECLAMPSIA Eclampsia - magnesium sulfateside effects:maternal hypotoniarespiratory depressioncardiac arrestneonatal depressioncontraindicated in myasthenia gravisuse with caution in renal insufficiencyManagement of ECLAMPSIA Eclampsia - anticonvulsant therapyphenytoinused extensively in Europemay be used in myasthenia gravismechanism of action - may increase gamma aminobutyric acid-mediated chloride conduction in postsynaptic membranesmay inhibit neurotransmitter inhibitory systemsManagement of ECLAMPSIA Eclampsia - phenytoindosage - 1 g loading dose over 1 hourcardiac monitoring during administrationside effectsarrhythmias with rapid administrationhepatitisSteven-Johnson syndromeManagement of ECLAMPSIA Eclampsia - anticonvulsant therapydiazepamuseful for status seizuresmechanism of action - facilitate the binding of GABA to its receptorbenzodiazepine receptorsdosage - 10 mg at a rate of 5 mg per minmay be repeated at 10 to 15 minute intervalsManagement of ECLAMPSIA Eclampsia - diazepamside effects - loss of consciousness, hypotension, respiratory depressioncaution - may increase risk of aspirationcauses prolonged depression of the neonatesodium thiopentotallong acting barbiturateused when sedation, paralysis and intubation neededManagement of ECLAMPSIA Eclampsia - which anticonvulsant to use?magnesium is associated with decreased recurrence risks of seizures when compared with diazepam or phenytoindiazepam is associated with increased need for mechanical ventilationManagement of ECLAMPSIA Eclampsia - management of fetusfetal bradycardia during seizure ~ 5 minutes after the onset of the seizuremay be associated with rebound tachycardiarecovery phase may show late decelerationsmonitor for uterine hypertonicityallow for fetal recoverymonitor for signs of abruptionManagement of ECLAMPSIA Eclampsiadelivery is indicated regardless of gestational ageimmediate cesarean delivery is not necessaryManagement of ECLAMPSIA After resuscitation 1.Insert canula size 102.Send blood to Lab for Hb, blood group, Platelet count, RFT, LFT, Uric acid concentration, coagulation study, RBS3.Urine catheter (to urine output & protein)

After the mother becomes stable1.Assessment of state of fetus (U/S, Doppler CTG)2.either : - Deliver the baby regardless of the gestational ageintense monitoring maternal health in hope of improvement fetal outcome by increase gestational age.Post natal managementIt is attention to fluid balance , BP , Renal & Hepatic function & CNS1.More aggressive control of BP2.MgSO4 maintained for 48 hrs at 1g/hr iv3.Subcutaneous heparin prophylaxisReferences Roopnarinesinghs Textbook of Obstetrics, 2008, 3rd edition, Published by Lexicon Trinidad Ltd, 2008. p61-88.Lecture Notes in Obstetrics and Gynaecology, 2004, 2nd edition, published by Blackwell Publishing Ltd, 1999. p122-127.Collins S. et al. Oxford Handbook of Obstetrics and Gynaecology 2nd ed. p62-68.Strikes Like Lightning: An EMS Case Review on Pre-eclampsia & Eclampisa, Anne Clouatre, 2009, Parker Emergency Medical Services.

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