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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
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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 pre-pregnancy 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 PRE-ECLAMPSIA < 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 PRE-ECLAMPSIA < 37 WEEKS AS IN PATIENT • 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 anti-hypertensive 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 • LabetololDosage: 200 to 600 mg bid to tid • NifedipineDosage: 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 • 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 Gluconate1gm (10 ml of 10% solution) IV slowly until caliumgluconate 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