1. Gestational Hypertension

2. Objectives Definitions Diagnosis Management -Fetal / Maternal assessment -Anti-Hypertensive therapy -Anti-Seizure therapy -Transport

3. Gestational Hypertension Definitions Preexisting hypertension Gestational hypertension -without proteinuria -with proteinuria -with proteinuria and adverse conditions Preexisting hypertension with superimposed gestational hypertension with proteinuria Unclassifiable antenatally

4. Gestational Hypertension Definitions Hypertension -absolute value of  140/90 mmHg  incremental rise of  30/15 mmHg  diastolic BP of ³ 90 mmHg sitting position with arm at heart level appropriate size cuff accurate mercury sphygmomanometer Korotkoff sounds I and IV recorded confirm BP in  4 hours unless very high

5. Gestational Hypertension Definitions Proteinuria -urine protein  2+ on dipstick -urine protein  300 mg/d on 24 hour collection proteinuria indicates glomerular dysfunction 24 hour urine should be considered if urine protein  1+ on dipstick edema may result from vasospasm and decreased oncotic pressure but this is not part of the definition

6. Gestational Hypertension Manifestations of Severity Gestational hypertension with adverse conditions diastolic BP > 110 mmHg laboratory evidence -  platelets,  LFT's,  uric acid renal effects - proteinuria > 3 g/d, oliguria CNS effects - seizure, headache, visual disturbances other organ involvement - lung, liver, hematologic fetal compromise - previously known as severe preeclampsia

7. Gestational Hypertension Incidence 10% of all pregnancies complicated by hypertension -one third of these will have proteinuria majority of preeclampsia in nulliparous patients -increased mortality risk in older gravidas -increased risk in first pregnancy with new partner -increased risk with preexisting hypertension, renal disease, diabetes mellitus preeclampsia is a leading cause of direct maternal mortality

8. Gestational Hypertension Management Stress reduction first Assessment of mother and fetus Treat blood pressure if dBP > 110 mmHg Treat nausea and vomiting Treat epigastric pain Consider seizure prophylaxis Consider timing/mode of delivery

9. Gestational Hypertension Stress Reduction component of maternal BP is adrenergic maternal discomfort must be minimized several components -quiet, dimly lit, isolated room -well planned management protocol -clear explanation of plan to patient/family -minimization of negative stimuli -consistent, confident team approach  nursing, obstetrics, anaesthesia, hematology, pediatrics

10. Gestational Hypertension Assessment of Mother - Clinical Blood Pressure -assess severity -consistency in measuring -relationship of high BP to CVA not seizure Central Nervous System -presence and severity of headache -vision disturbances - blurring, scotomata -tremulousness, irritability, hyperreflexia, somnolence -nausea and vomiting

11. Gestational Hypertension Assessment of Mother - Clinical Hematologic -edema -bleeding, petechiae Hepatic -RUQ and epigastric pain -nausea and vomiting Renal -urine output and colour

12. Gestational Hypertension Assessment of Mother - Laboratory Hematologic -hemoglobin, platelets, blood film -PTT, INR, fibrinogen, FDP -LDH, uric acid, bilirubin Hepatic -ALT, AST -(glucose, ammonia to R/O AFLP) Renal -proteinuria -creatinine, urea, uric acid

13. Gestational Hypertension Assessment of Fetus Fetal movement Fetal heart rate assessment Ultrasound for growth Biophysical profile Amniotic fluid volume Doppler flow studies

14. Gestational Hypertension Treatment Nausea and Vomiting -antiemetic of choice RUQ / Epigastric Pain -morphine 2 - 4 mg IV -antacid -minimize palpation

15. Gestational Hypertension Anti-hypertensive Therapy - Goals minimize risk of maternal CVA maximize maternal condition for safe delivery gain time for further assessment -facilitate vaginal delivery if possible -prolong gestation where appropriate/feasible

16. Gestational Hypertension Anti-hypertensive Agents - Acute Therapy Arteriolar Dilators -hydralazine ß-Blockers -labetalol Calcium Channel Blockers -nifedipine

17. Gestational Hypertension Anti-hypertensive Agents - Maintenance Therapy Centrally Acting Sympatholytic Agents -methyl-dopa ß-Blockers -atenolol -labetalol Calcium Channel Blockers -nifedipine  ACE inhibitors are contraindicated in pregnancy

18. Gestational Hypertension Hydralazine direct vasodilator, first line agent in acute settings intravenous rapid onset useful for hypertensive crisis can be used orally Dosage - 5 mg IV test dose  5-10 mg q 20-40 minutes Cautions - hypotension with fetal compromise may occur in slow acetylators and hypovolemic patients Side Effects - may cause flushing, headache, tachycardia

19. Gestational Hypertension Methyldopa centrally acting a 2 -receptor agonist, oral agent long history of safe use in pregnancy, well tolerated some concern regarding ability to control BP not for use in acute settings Dosage - 500 - 3000 mg po in 2 - 4 divided doses Cautions - drug of choice in essential hypertension Benefits - minimal side-effects and safe

20. Gestational Hypertension Atenolol ß 1 -receptor antagonist, oral agent  cardiac output,  renin release, vasomotor inhibitor onset of action in 1 hour peak levels in 2-4 hours long half life  once a day dosing Dosage - 50 -100 mg po OD Cautions - DM, asthma,  baseline FH, variability present -risk of IUGR with chronic use Benefits - often only agent needed

21. Gestational Hypertension Labetalol combined  1 and ß-blocker with ISA intravenous rapid onset useful for hypertensive crisis can be used orally Dosage - maximum 300 mg IV dose -20 mg IV followed by 20-80 mg IV titrated to BP Cautions - concern re: fetal responses to hypoxia Benefits - dependable, titratable, familiar

22. Gestational Hypertension Nifedipine calcium channel blocker, oral agent direct relaxation of vascular smooth muscle rapid onset of action if regular capsule used Dosage - Adalat-PA 10 mg bid  40 mg bid Side Effects - magnesium toxicity, edema, flushing, headache, palpitations, tocolytic  use of short acting form discouraged

23. Gestational Hypertension Hypertensive Crisis Stabilize severe hypertension -use hydralazine, ß-blocker, and/or Adalat-PA -goal  maintain diastolic BP at 90 - 100 mmHg -monitor fetal status while treating BP Seizure prophylaxis Intravascular volume status -Foley catheter  seldom experience ARF -do not fluid overload  seldom require CVP line Deliver

24. Gestational Hypertension Seizure Prophylaxis difficult to predict who will seize -not directly related to degree of hypertension or level of proteinuria high 'number needed to treat' to prevent seizure agents not innocuous nor completely effective MgSO 4 is agent of choice when seizure prophylaxis is felt to be indicated

25. Gestational Hypertension Magnesium Sulfate obstetrical standard but not used in other settings superior to phenytoin for prophylaxis superior to phenytoin or diazepam in preventing recurrence Dosage - 4 g IV followed by 1 - 4 g / hour IV or 4 g IM q4h Side Effects - weakness, paralysis, cardiac toxicity Monitor - reflexes, respiration, level of consciousness

26. Gestational Hypertension Magnesium Sulfate - Overdose close observation for side effects -weakness, respiratory paralysis, somnolence especially high risk in those with oliguria or receiving Ca 2+ channel blockers ANTIDOTE stop magnesium infusion 10% Calcium gluconate 10 mL IV over 3 minutes

27. Gestational Hypertension Transport consider transport only if resources limited and maternal/fetal condition permits maternal BP and symptoms stable fetal status reassuring appropriate anti-hypertensive agents started MgSO 4 started if appropriate discuss with accepting centre and patient/family MgSO 4 and anti-hypertensives potentially fatal in overdose

28. Gestational Hypertension When to Deliver  37 weeks with gestational hypertension  34 weeks with severe gestational hypertension < 34 weeks with any of: -poorly controlled dBP -lab evidence of worsening end-organ involvement -suspected fetal compromise -uncontrolled seizures -symptoms unresponsive to appropriate therapy

29. Gestational Hypertension Delivery - The Cure timely delivery minimizes maternal and neonatal morbidity and mortality optimize maternal status before interventions to deliver delay delivery to gain fetal maturity and to allow transfer only when maternal and fetal condition allow it gestational hypertension is a progressive disease, expectant management is potentially harmful in presence of severe disease or suspected fetal compromise

30. Gestational Hypertension Peri- and Postpartum Management do not drop BP too low risking fetal compromise do not fluid overload epidural analgesia is favoured in the absence of low platelets or coagulopathy multi-specialty approach patient must be monitored post-partum