HYPERTENSION IN PREGNANCY AND ECLAMPSIA

Hypertension in pregnancy

1. HYPERTENSION IN PREGNANCY Lindelani Malinda Micah Maharaj Resource Day: 30-01-2020

2. Objectives Introduction Classification and definition of hypertension in pregnancy Investigations Complications Management Eclampsia 2

3. Introduction Complicates up to 10% of pregnancies Represents significant Maternal and Perinatal morbidity and Mortality Hypertensive disorders of pregnancy is an umbrella term encompassing preexisting , gestational hypertension ,preeclampsia and it complications 3

4. Definition Hypertension is defined as -: Blood pressure of >/= 140/90 mmHg Increase in systolic of 30mmHg Increase in Diastolic 15mmHg 4

5. Classification and definition of hypertension in pregnancy Gestational hypertension Pre-eclampsia Chronic hypertension Chronic hypertension with superimposed pre-eclampsia White coat Hypertension 5

6. Gestational hypertension Hypertension after 20 weeks gestation on two or more occasions 4 hours apart without proteinuria on a previously normotensive patient and resolves within 6 weeks post delivery 6

7. B. Chronic hypertension Essential: Blood pressure greater than 140/90 mmHg preconception or prior to 20 weeks without an underlying cause Secondary Hypertension : chronic kidney disease endocrine disorders coarctation of the aorta 7

8. C. Chronic hypertension with superimposed pre-eclampsia The new development after 20 weeks gestation of one or more of the features of pre-eclampsia in a patient with preexisting chronic hypertension 8

9. D. Pre-eclampsia New onset Hypertension that arises after 20 weeks of gestation and returning to normal within 6 weeks post partum ,and is associated with proteinuria . Further classified Pre eclampsia with Severe Features Imminent Eclampsia Eclampsia 9

10. Risk factors of Hypertension In Pregnancy Maternal Primigravida Family history of pregnancy induced hypertension DM, Chronic HPT, Renal insufficiency Anti-phospholipid syndrome and inherited thrombophilia Extremes of maternal age (18< or >35 ) Vascular or connective tissue disease High BMI 10

11. Fetal Multiple gestation Unexplained fetal growth restriction Previous unexplained stillbirths Hydrops fetalis Paternal Primi paternity Male Partner whose previous partner had preeclampsia 11

12. Socio economic Low socio economic status Recreational drug use Smoking Alcohol Stress 12

13. PRE-ECLAMPSIA PATHOPHYSIOLOGY Immune factors , genetic factors , dietary factors, CKD , unknown factors Trophoblastic maladaptation Reduced uteroplacental perfusion Cellular anoxia Release of angiogenic factors, apoptotic cells and trophoblastic debris Vascular endothelial damage Organ system involvement Clinical signs and then ^BP, proteinuria and IUGR 13

14. Complications Materna l Renal failure Cardiac failure Liver failure Eclampsia pulmonary edema Abruptio placentae Stroke HELLP Syndrome Thrombocytopenia Fetal Placental Insufficiency Placental infarctions IUGR Fetal distress Fetal death 14

15. 15 Chronic hypertension Pre-eclampsia Superimposed pre-eclampsia age Usually > 30 years Young or > 35 years Usually >30 years gravidity multigravida primigravida multigravida Order of signs Fall pregnant while hypertensive Weight gain HPT Oedema proteinuria Already hypertensive. Develops severe HPT and proteinuria Eclampsia Risk:maternal and fetal Low to mild Mild to high high Risk of recurring in subsequent pregnancies high Small high Renal function Relatively unaffected Early increase in urea,creatinine,urates Incr urea and creatinine but urate can rise disproportioally d/t pre- eclmpsia DIFFERENCES BETWEEN THESE DISORDERS

16. Principles in management of pre- eclampsia Admit to hospital : Establish aetiology of hypertension To plan treatment To evaluate prognosis History-taking: Previous history of hypertension Family History of Hypertension Evidence of other organ involvement Cardiac Renal Continuing Assessment 4-hourly BP recording Maternal investigations Foetal surveillance 16

17. Principles in management of pre-eclampsia Control BP prevent eclampsia Check and correct complications Assess fetal compartment Definite management is delivery 17

18. I nvestigations 18 Mother Fetus Blood : Hb Gestational age Platelets Fetal activity (kick count) Urea, creatinine, uric acid Non-stress test 24-hr proteinuria Ultrasound Biometry Amniotic Fluid volume Doppler If thrombocytopenia present : peripheral blood smear Coagulation: ptt LFT:ALT, AST& LDH optional ECG, Echo ,chest x-ray

19. I nvestigations Urine dipstick: 1+ is eqv. to ± 300mg proteinuria 2+ is eqv. to ± 1000mg protein=> nephrotic range proteinuria 3+ is eqv. to ± 4000mg/dl FBC: ↓platelets, Hb 19

20. Management of pre- eclampsia Management is done according to clinical group: Patients before with Severe early onset PET 24 weeks gestation: TOP is advised Between 24 and 34 weeks: Room for conservative management if both Maternal and Fetal Compartments are stable After 34 weeks: D elivery 20

21. Prevention of Pre- eclampsia LOW DOSE ASPIRIN (1mg/kg/daily) Indications include: History of early-onset pre- eclampsia Collagen Vascular Disease Recurrent pre- eclampsia in previous pregnancies Previous hypertension with perinatal mortality Recurrent foetal growth impairment of unknown aetiology Calcium (100-1500g/daily) is also used in the prevention of pre – eclampsia . 21

22. Management of Pre- eclampsia AIM of management is to maximise good perinatal outcomes without endangering maternal health. ANTIHYPERTENSIVE TREATMENT. ASSESSING FOR COMPLICATIONS FETAL MONITORING USE OF MAGNESIUM SULPHATE TIMING AND MODE OF DELIVERY 22

23. CONTROL OF BLOOD PRESSURE DRUGS SUITABLE IN PREGNANCY Alpha-receptor antagonists: Methyldopa Loading dose: 1-2 g po Continuation: 500mg 3 times daily to maximum of 2g daily Alpha and beta-receptor antagonists: Labetalol Can be used as a short acting agent Calcium channel blockers: Nifedipine Long acting used both ante and post partum Or short acting agent: 10 mg oral Arteriolar Vasodilators: Hydralazine Adjunct to methyldopa Can be used as a rapid agent 23

24. Cont… If BP is >140/90, commence treatment with Aldomet (Methyldopa) at a dose of 500mg 6 hourly or 8 hourly depending on BP. Should the BP be poorly controlled on Aldomet ie . 2 BP spikes in 24 hours requiring use of a rapid-acting agent, add a second agent. Adalat (Nifedipine ) starting at 10mg 8 hourly up to a maximum of 20mg 6-hourly Hydralazine is the third-line agent and can be started at a dose of 1mg 8 hourly up to a maximum of 7mg 8 hourly . 24

25. Cont.…. BP > 170/110 - should be treated as a hypertensive emergency Start a Labetalol infusion : 200mg in 200mls normal saline at 20/40/80 ml.hr titrated against the BP every 30 minutes. Caution in patients with tachycardia. Alternatively administer Nifedipine capsules 10 mg orally immediately, and if necessary 20-30 minutes later. Avoid sublingual Nifedipine . The goal should be to lower BP to 140/90 – 150/90. 25

26. Cont .. Goal: Maintenance of maternal well-being and delivery of infant who will survive and develop normally . Thus, delivery is delayed Unless deterioration in the maternal or foetal condition becomes a dominant feature. Betamethasone 12mg 12-hourly (two doses) to stimulate foetal maturity for pregnancies less than 34 weeks 26

27. IMMINENT ECLAMPSIA Symptoms Severe headache, not responding to simple analgesics Visual disturbances Nausea & Vomiting Epigastric pain Signs Increased knee jerks (hyperreflexia) Clonus Retinal spasm 27

28. IMMINENT ECLAMPSIA-TREATMENT 1. Definitive management is Delivery Lower blood pressure Maintenance of MGSO4 Check complication Assess Fetal compartment 28

29. ECLAMPSIA DEFINITION: CONVULSIONS associated with hypertension and proteinuria in pregnancy to up 6weeks postpartum . 29

30. ECLAMPSIA-MANAGEMENT Check circulation, airways and breathing Place the patient in the left lateral position Administer oxygen – 6 to 8L / per minute Give Magnesium Sulphate for treatment and prevention of further seizures Reduce blood pressure as per regimen Investigate for complications Definitive management is delivery 30

31. Continuation Neuro protection for at least 24 hours if: Poor arterial blood gases Unconscious/ GCS <8/15 Extreme restlessness Laryngeal Oedema Aspiration 31

32. MAGNESIUM SULFATE MgSO4 used to control convulsions and prevent further convulsions. SIBAI’S INTRAVENOUS REGIMEN Loading dose: 6g in 200ml over 20mins IV Maintenance: 2g/hour IV Continued until 24 hours post-delivery. PRITCHARD’S INTRAMUSCULAR REGIMEN Loading dose:14g (4g IV over 5 mins and 10g IM, 5g in each buttock) Maintenance: 5g 4-hourly IM. This is used in primary care . ZUSPAN REGIMEN Loading dose: 4g in 200ml IV over 15-20 minutes Maintenance : 1 g hourly given by infusion pump 32

33. MAGNESIUM SULFATE Indications severe pre-eclampsia Imminent eclampsia eclampsia T oxicity Manifests with: Loss of patellar reflexes Weakness; Drowsiness Nausea Muscle paralysis Respiratory Depression 33

34. Monitoring Check the following signs every 4 hours before commencing the next dose of magnesium sulphate. Presence of peripheral knee or arm reflexes Respiratory rate above 16 per minute Urine output of more than 30 mls per hour Monitor Blood pressure recording every 10-20 minutes. ½ Hourly pulse and urine output. Pulse oximeter if available 34

35. Magnesium Sulphate Levels Normal range 0.7 – 1.0mmol/L Therapeutic Level 1.25 – 3.25 mmol /L Reflexes disappear 4-5 mmol /L Respiratory depression 6-8 mmol /L Cardiac Arrest > 15m.mol/L 35

36. MAGNESIUM SULFATE- TOXICITY TO REVERSE MG TOXICITY: RULE OF 10 Calcium Gluconate 10% at a dosage of 10 ml slowly intravenously over 10 minutes 36