Transcript HYPERTENSIVE DISORDERS OF PREGNANCY

HYPERTENSIVE DISORDERS OF
PREGNANCY
Dr. Dianne MP Graham, MD, CCFP
Based on Guidelines From SOGC ALARM Course
& WHO Guide on Managing Complications in Pregnancy and
Childbirth
Why Recognize and Treat Hypertensive
Disorders of Pregnancy?
• Fourth leading cause of maternal death in
pregnancy
• Those that survive can have major end organ
damage such as stroke, kidney or hepatic
failure
• Major cause of fetal morbidity such as IUGR,
prematurity and fetal hypoxia
DEFINITIONS
• 1. Chronic Hypertension (Onset before 20
weeks gestation.)
• 2. Chronic Hypertension with Superimposed
Mild pre-eclampsia
• 3.Pregnancy Induced Hypertension
• 4. Mild Pre-eclampsia
• 5. Severe Pre-eclampsia
• 6.Eclampsia
CHRONIC HYPERTENSION
MANAGEMENT
• Diastolic blood pressure 90 mm Hg or more
before first 20 weeks of gestation
• Encourage additional periods of rest
• Do not lower blood pressure below prepregnancy levels……higher levels of BP maintain
renal and placental perfusion
• If patient was on anti-hypertensive meds before
pregnancy continue them as long as they’re
considered safe in pregnancy or switch to ones
that are safe
CHRONIC HYPERTENSION
MANAGEMENT
• If diastolic BP is 110 mm Hg or more treat with
anti-hypertensive drugs
• If PROTEINURIA (urine protein dipstick 1+ or
more) treat for Pre-eclampsia
• Monitor fetal growth & condition
• If there are no complications deliver at term
• If pre-eclampsia develops treat as for mild or
severe pre-eclampsia
PREGNANCY INDUCED HYPERTENSION
• Two readings of diastolic BP 90-110 Hg 4 hours apart
after 20 weeks gestation
• No proteinuria
• In PIH there may be NO symptoms and the only sign
may be hypertension
• Monitor mother weekly for BP, urine protein and
educate patients and family to ominous symptoms
• Monitor fetal growth and well being weekly
• Treat with medication if BP is >110 mmHG
• Do not restrict salt
MILD PRE-ECLAMPSIA
• Two readings of diastolic BP 90-110 mmHg 4
hours apart after 20 weeks gestation
• Proteinuria up to 2+
• Mild pre-eclampsia can progress rapidly to
severe pre-eclampsia…..monitor closely
• Educate patient and family as to signs of
severe pre-eclampsia and eclampsia
MANAGEMENT OF MILD PREECLAMPSIA < 37 WEEKS
• Monitor BP, urine (for proteinuria), reflexes and
fetal movement twice a week as an outpatient if
signs remain unchanged or normalize
• Counsel woman and her family as to danger signs
of severe pre-eclampsia or eclampsia
• Encourage additional periods of rest
• Encourage woman to eat a normal diet. Do NOT
advise salt restriction
• Do NOT give anti-convulsants, antihypertensives,
sedatives or tranquilizers.
MANAGEMENT OF MILD PREECLAMPSIA < 37 WEEKS AS IN PATIENT
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Provide normal diet (No salt restriction)
Monitor BP (twice daily)
Monitor urine for proteinuria (once a day)
Do not give anticonvulsants, antihypertensives
or sedatives unless BP rises or urinary protein
level increases.
• Do not give diuretics. They are harmful and
should only be used in pre-eclampsia with
signs of pulmonary edema or heart failure
MILD PRE-ECLAMPSIA <37 WEEKS
MANAGEMENT AS OUTPATIENT
• If diastolic BP decreases to normal in hospital &
condition remains stable she can be sent home
• Advise to rest and watch out for significant signs
of severe pre-eclampsia
• See her twice a week to monitor BP, urine for
proteinuria and fetal condition and to assess for
symptoms and signs of severe pre-eclampsia
• If diastolic BP rises again readmit her
SIGNS OF SEVERE PRE-ECLAMPSIA
• Central Nervous System: Frontal headache, visual
disturbance, tremulousness, irritability,
somnolence, seizures
• Renal: Proteinuria, oliguria<500 ml/24 hour
• Hepatic: severe nausea & vomiting,
RUQ/Epigastric pain
• Hematologic: bleeding, petechiae, decreased
platelets
• Vascular: diastolic BP >110 or pulmonary edema,
non-dependant edema
SEVERE PRE-ECLAMPSIA
-Diastolic BP of 110 mmHg or more after 20
weeks gestation
-Proteinuria 3+ or more
-Management is always active not expectant
-Severe pre-eclampsia can progress to eclampsia
rapidly and is not related to how high the BP is
-In severe pre-eclampsia delivery should occur in
24 hours.
ANTI-HYPERTENSIVE THERAPY GOALS
• If diastolic BP is 110 mm Hg or more give antihypertensive drugs
• The goal is to keep diastolic BP between 90
mm Hg and 100 mm Hg to prevent cerebral
hemorrhage
• Helps maximize maternal safety for safe
delivery
ANTIHYPERTENSIVE DRUGS ACUTE
• Administered by IV route
• Hydralazine is drug of choice (arteriolar
dilator) –Dosage: 5 mg IV test dose slowly
over 5 minutes followed by 5-10mg IV q20
minutes until BP is lowered. Repeat hourly as
needed or give hydralazine 12.5 mg I.M. every
two hours as needed.
• Severe hypotension may occur with
hydralazine if patient is hypovolemic
ANTIHYPERTENSIVE DRUGS ACUTE
• If hydralazine is not available , give labetolol or
nifidepine
• Labetolol Dosage: 10 mg IV
• If response to Labetolol inadequate (diastolic
BP remains above 110mm Hg) after 10
minutes give Labetolol 20 mg IV
• Increase dose of to 40 mg and then 80 mg if
satisfactory response is not obtained after 10
minutes of each dose
ANTIHYPERTENSIVE DRUGS ACUTE
• Nifedipine : Dosage: 5 mg under the tongue
• If response to nifedipine is inadequate
(diastolic BP remains above 110 mm Hg after
10 minutes, give an additional 5 mg under
tongue
• CAUTION: Magnesium toxicity can occur with
combining nifedipine with MgSO4
ANTIHYPERTENSIVE DRUGS ORAL
• For maintenance in cases of chronic
hypertension, gestational hypertension and
mild pre-eclampsia
• Aldomet (alpha-methyl-dopa) Dosage: 500 mg
to 1000 mg bid to qid. Maximum dose 3000
mg daily
• Labetolol Dosage: 200 to 600 mg bid to tid
• Nifedipine Dosage: 20 to 40 mg bid
SEIZURE PROHYLAXIS
• Difficult to predict who will seize.
• Seizures not directly related to degree of
hypertension or level of proteinuria
• Magnesium Sulfate is drug of choice when
seizure prophylaxis is indicated. Dosage:4 gm
IV followed by 1-2 g/hour IV
• MgSO4 is superior to phenytoin or diazepam
in prophylaxis and treatment of seizures in
pregnancy
ECLAMPSIA
• Convulsions
• Diastolic BP 90 mm Hg or more after 20 weeks
gestation
• Proteinuria of 2+ or more
• Coma
• Clonus
MANAGEMENT OF ECLAMPSIA
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Call for help
Maternal left lateral position
Protect the airway
Establish IV access of Normal saline or Ringers
MgSO4
Post-Seizure: airway, oxygen, vital signs, fetal
surveillance
• assess for signs of abruption
MAGNESIUM SULFATE
• Loading Dosage: Give 4 gm of 20% magnesium
sulfate IV over five minutes
• Follow promptly with 10 gm of 50% MgSO4
solution. Give 5 gm in each buttock as a deep IM
shot with 1 ml of 2%lignocaine in the same
syringe. Warn patient that a feeling of warmth
will be felt when MgSO4 is given.
• If convulsions recur after 15 minutes give 2 gm of
50% MgSO4 IV over 5 minutes
MAGNESIUM SULFATE
• Maintenance Dose: Give 5 Gm of 50% MgNO4
with 1 ml of 2% lidocaine in same syringe by
deep IM injection every four hours. Continue
this treatment for 24 hours after delivery or
the last convulsion (whichever occurs last)
• If 50% solution is not available give 1 gm of
20% MgSO4 solution IV every hour by
continuous infusion
TOXICITY SIGNS FROM MAGNESIUM
SULFATE
• Closely monitor the woman for signs of
toxicity
• WITHHOLD OR DELAY DRUG IF:
• Respiratory rate falls below 16 per minute
• Patellar reflexes are absent
• Urinary output falls below 30 ml per hour over
preceding four hours
MAGNESIUM SULFATE TOXICITY
MANAGEMENT
• KEEP ANTIDOTE READY
• In case of respiratory arrest:
• Assist ventilation (mask and bag, anaesthesia
apparatus, intubation)
• Give Calcium Gluconate 1gm (10 ml of 10%
solution) IV slowly until calium gluconate
begins to antagonize the effects of magnesium
sulfate and respiration begins.
REMEMBER
• 50% of patients seize before delivery
• 25% seize during delivery
• 25% of patients seize in the first 24 hours
AFTER delivery
• NEVER use ergometrine in patients with
gestational hypertension or pre-eclampsia as
it increases risk of seizures!!!!
DELIVERY- THE CURE
• Timely delivery minimizes morbidity and
mortality
• Stabilize mother before delivery
• Delay delivery to gain fetal maturity only when
maternal and fetal condition allows
• Gestational hypertension is a progressive disease
• Expectant management is potentially harmful in
presence of severe disease or suspected fetal
compromise
PERI AND POSTPARTUM
MANAGEMENT
• Avoid abrupt drop in BP – aim for 80 -100 mm
Hg diastolic
• Avoid fluid overload
• Patient MUST be monitored closely after
delivery