HYPERTENSIVE DISORDERS IN PREGANCY

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HYPERTENSIVE DISORDERS IN PREGANCY
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OBJECTIVES

• At the end of this session you should be able to
• Outline diagnostic features of pre-eclampsia
• Classify pre-eclampsia according to severity
• Outline risk factors for pre-eclampsia
• Outline maternal and fetal complications of
  pre-eclampsia.
• Describe the management of pre-eclampsia and
  eclampsia.

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I. INTRODUCTION

• Synonyms
• Toxemia of pregnancy, pre-eclampsia, EPH
  gestosis, pregnancy induced hypertension.
• Pre-eclampsia commonly manifests after the 20th
  week of pregnancy.
• Prevalence of pre-eclampsia varies from one
  place to another
• Severe pre-eclampsia and eclampsia
• Are serious and potentially fatal
• Third commonest cause of maternal mortality
• Occurs prior to, during or after delivery

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II. DIAGNOSIS OF PRE-ECLAMPSIA

• When SBP gt 140 mm Hg, DBP gt 90 mm Hg in a woman
  known to be normotensive prior to pregnancy.
• The diagnosis requires 2 such abnormal BP
  measurements recorded at least 6 hours apart.

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III. RISK FACTORS

• Young maternal age
• Nulliparity 85 of pre-eclampsia occur in
  primigravida.
• Increased placental tissue for gestational age
  Hydatiform moles, twin pregnancies
• Family history of pre -eclampsia
• Diabetes mellitus
• Renal diseases,
• Chromosomal abnormality in the fetus (eg,
  trisomy).

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RISK FACTORS cont

• Worrisome signs for pre-eclapmsia development
• Rapid increase of weight during the latter ½ of
  pregnancy
• An upward trend in diastolic BP even while still
  within normal range

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IV. CLASSIFICATION OF PRE ECLAMPSIAACCORDING TO
SEVERITY

• Mild pre-eclampsia
• Moderate pre-eclampsia
• Severe pre-eclampsia
• Mild to Moderate Pre eclampsia
• Diagnostic Features
• Systolic BP is 140 -160 mmHg
• Diastolic BP is 90 100 mmHg
• Proteinuria up to

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2. Severe pre-eclampsia

• Also called Imminent eclampsia
• Symptoms
• Severe persistent occipital or frontal
  headaches
• Visual disturbance blurred vision, photophobia
• Epigastric and/or right upper-quadrant pain
• Signs
• Diastolic BP gt 11ommHg, systolic BP gt 160mmHg
• Proteinuria or more
• Altered mental status
• Hyper-reflexia
• Oliguria

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HELLP SYNDROME

• Is a severe form of pre-eclampsia

• Affects approx 10 of women with severe
  preeclampsia and 30-50 of women with eclampsia.
• Characterized by
• Hemolysis,
• Elevated liver enzymes
• Low platelet count.
• Increased mortality rate and DIC

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V. PATHOPHYSIOLOGY

• There are several theories and etiologic
  mechanisms.
• Vasospasm theory Most favored theory
• Vasospasms ? vasoconstriction ? resistance ?
  arterial BP
• Eclampsia
• Cerebral arterial vasospasm ? cerebral edema or
  infarction and/or cerebral hemorrhage

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VI. COMPLICATIONS OF SEVERE PRE-ECLAMPSIA AND
ECLAMPSIA

• Maternal complications

• CVS
• Haemoconcentration (cause vasoconstriction and
  vascular permeability)
• Hamatological changes HELLP ? DIC
• Kidneys
• Decr RBF? ?GFR ? RTN and RCN? acute RF
• Proteinuria due to ?permeability to large
  protein,
• Oliguria both renal perfusion and GFR decrease.

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COMPLICATIONS OF SEVERE PRE ECLAMPSIA AND
ECLAMPSIA cont

• Brain
• Cerebral edema
• Infarction, cerebral hemorrhage
• Blindness Due to -?retinal artery vasospasms and
  retinal detachment
• Fever 39ºC a grave sign, may be a consequence
  of intracranial hemorrhage.
• Coma may be a result of CVA

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COMPLICATIONS OF SEVERE PRE ECLAMPSIA AND
ECLAMPSIA cont

• RS Pulmonary oedema and cyanosis
• Utero-placental perfusion
• Vasospasms ? decr perfusion ? distress and death
• Histological changes in the placental bed acute
  artherosis lipid rich cells of the
  uteroplacental arteries
• Fetal complications
• IUFD, IUGR

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MAJOR CAUSES OF MATERNAL DEATH

• Cerebrovascular accident (CVA)
• Pulmonary oedema
• Cardiac failure,
• Renal failure

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VII. WORK UP - INVESTIGATIONS

• Urine analysis
• Proteinuria
• A 24-hour urine collection
• Quantity of urine and protein
• Uric acid level
• GFR and creatinine clearance decrease ?in ?uric
  acid levels.
• LFT Transaminases
• USS fetal wellbeing, if the GA is lt 20/40 R/O
  moles.

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VIII. MANAGEMENT OF PRE ECLAMPSIA

• MILD - MOD PRE ECLAMPSIA
• A Dispensary Health centre
• Antihypertensives
• Aldomet 250 mg 8 hourly for 7 days,
• Bed rest at home
• REFER within one week to Hospital for further
  management

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MANAGEMENT OF PRE ECLAMPSIA

• 1. MILD - MOD PRE ECLAMPSIA cont
• B. Hospital
• Antihypertensives Aldomet,
• Bed rest at home,
• Sequential work ups,
• Fetal movements monitoring,
• Schedule antenatal clinic every 2 weeks up to 32
  wks and weekly thereafter

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MANAGEMENT OF PRE ECLAMPSIA

• 1. MILD - MOD PRE ECLAMPSIA cont
• B. Hospital
• Strongly advice the woman to deliver in a
  hospital
• Plan delivery at 38/40
• Advice the mother to come to the health facility
  in case of severe headache, blurred vision,
  nausea or upper abdominal pain.
• Manage as severe pre-eclampsia If not responding
  to treatment i.e. if the systolic BP is gt 160
  mmHg, or the diastolic BP is gt 100mmHg or there
  is proteinuria

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MANAGEMENT OF SEVERE PRE ECLAMPSIA AND ECLAMPSIA

• Note Severe pre-eclampsia is managed like
• eclampsia
• Management protocol for eclampsia
• Keep airway clear
• Control convulsions
• Control BP
• Control fluid balance
• Antibiotics
• Investigations
• Deliver the mother

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MANAGEMENT CONT

• BP CONTROL
• Keep SBP between 140 -160 mm Hg and DBP between
  90 -110 mm Hg
• ?Why these levels Avoid potential reduction in
  either uteroplacental blood flow or cerebral
  perfusion pressure.
• Drugs
• Anti HPTs Hydralazine, nifedipine, or labetalol
• Diuretics are not used except in the presence of
  pulmonary edema

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MANAGEMENT CONTROL CONVULSIONS

• I. An overview on MgSO4.
• Mechanism
• Cerebral vasodilator ? reducing cerebral
  vasospasm ? ?ischemia (brain).
• Superior to other anti-convulsants used to
  control and prevent fits
• Important part of mgt of eclampsia
• Recurrence rate after MgSO4 10 -15
• Improves maternal and fetal outcome

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• CONTROL CONVULSIONS - REGIMEN

• 1. INTRAMUSCULAR REGIMEN
• i. Loading dose
• Give MgSO4 4 g (i.e. 20mls of 20 solution)
  200mls NS or sterile water I.V over 5 minutes
• Follow promptly with 10g (i.e. 20ml of 50
  solution), 5g in each buttock as deep I.M with
  1ml of 2 lignocaine in the same syringe

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MANAGEMENT CONT

• CONTROL CONVULSIONS - REGIMEN

• 1. INTRAMUSCULAR REGIMEN cont
• ii. Maintenance dose
• MgSO4 5 g (i.e. 10ml of 50 solution) 1 ml
  lignocaine 2 4 hourly in alternate buttocks.
• NOTE
• IM inj. are painful and are complicated by local
  abscess formation in 0.5 of cases.
• The intravenous (IV) route is therefore preferred

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MANAGEMENT CONT

• CONTROL CONVULSIONS - REGIMEN

• 2. INTRAVENOUS REGIMEN
• i. Loading dose
• MgSO4 4 g (i.e. 20mls of 20 solution) 200mls
  NS I.V over 5 minutes
• ii. Maintenance dose
• MgSO4 4 g (i.e. 20ml of 20 solution) IN 500ml
  NS 4 hourly for 24 hrs after the last fits

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MANAGEMENT CONT

• CONTROL CONVULSIONS - REGIMEN

• Recurrent fits (any regimen)
• Therapeutic dose may not have been reached
• Give 2g (i.e. 10ml of 20 solution) i.v. over 5
  minutes
• Treatment duration
• Continue for 24 hours after delivery or last
  convulsion, whichever occurs first

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MANAGEMENT CONT

• Magnesium toxicity

• Causes loss of deep tendon reflexes, followed by
• respiratory depression and ultimately respiratory
• arrest.
• Thus, before repeating MgSO4, ensure that
• RR 16/min
• Patellar reflexes are present
• Urinary output is at least 30ml per hour over 4
  hours
• Otherwise withhold or delay MgSO4
• Keep antidote ready
• In case of respiratory arrest Assist
  ventilation and administer calcium gluconate

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MANAGEMENT CONT

• DELIVER THE MOTHER

• Delivery should be within 6-8 hours of onset of
  fits
• Vaginal delivery is the safest mode of delivery
• Assessment
• R/O contraindications to SVD
• Bishop score
• If the cervix is favourable - induce labour
• Otherwise prepare for C/S

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MANAGEMENT CONT

• Management of labour

• 1st stage
• Relieve pain pethidine 25 mg iv every 2-4 hours
• Augmentation of labour
• Monitor FHR,
• 2nd stage Assist with vacuum extraction
• 3rd stage Active management
• Oxytocin 10 IU i.m after delivery of anterior
  shoulder
• Cord traction
• Squeezing clots after delivery of the placenta

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MANAGEMENT CONT

• Management of labour

• If there is delay perform C/S
• Post delivery
• Continue observation for at least 48 hrs post
  delivery
• Record and monitor BP and urine output for at
  least 48 hours after delivery,
• Keep the pt in hospital until BP stabilizes,
• Continue with aldomet PO until BP back to normal