高血压英文ppt精品课件 hypertension in

Hypertension in Pregnancy Lianne Beck, MD Assistant Professor Emory Family Medicine OBJECTIVES n Know criteria for the diagnosis of chronic hypertension, gestational hypertension and preeclampsia n List criteria for the diagnosis of severe preeclampsia/HELLP syndrome n Discuss current management considerations Introduction n Most common medical complication of pregnancy n 6 to 8 % of gestations in the US. n In 2000, the National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy defined four categories of hypertension in pregnancy: q Chronic hypertension q Gestational hypertension q Preeclampsia q Preeclampsia superimposed on chronic hypertension Chronic Hypertension Defined n BP measurement of 140/90 mm Hg or more on two occasions n Before 20 weeks of gestation OR Persisting beyond 12 weeks postpartum Chronic Hypertension n Treatment of mild to moderate chronic hypertension neither benefits the fetus nor prevents preeclampsia. n Excessively lowering blood pressure may result in decreased placental perfusion and adverse perinatal outcomes. n When BP is 150 to 180/100 to 110 mm Hg, pharmacologic treatment is needed to prevent maternal end-organ damage. Treatment of Chronic Hypertension n Methyldopa , labetalol, and nifedipine most common oral agents. n AVOID: ACEI and ARBs, atenolol, thiazide diuretics n Women in active labor with uncontrolled severe chronic hypertension require treatment with intravenous labetalol or hydralazine. Gestational Hypertension n Formerly called PIH (Pregnancy Induced HTN) n HTN without proteinuria occurring after 20 weeks gestation and returning to normal within 12 weeks after delivery. n 50% of women diagnosed with gestational hypertension between 24 and 35 weeks develop preeclampsia. Older Criteria for Gestational HTN n 30/15 increase in BP over baseline levels n No longer appropriate n 73% of patients will exceed 30 mm systolic and 57% will exceed 20 mm diastolic Preeclampsia n New onset hypertension with proteinuria after 20 weeks gestation. n Resolves by 6 weeks postpartum. n Characterized as mild or severe based on the degree of hypertension and proteinuria, and the presence of symptoms resulting from involvement of the kidneys, brain, liver, and cardiovascular system Risk Factors FACTOR RISK RATIO Renal disease 20:1 Chronic hypertension 10:1 Antiphospholipid syndrome 10:1 Family history of PIH 5:1 Twin gestation 4:1 Nulliparity 3:1 Age 40 3:1 Diabetes mellitus 2:1 African American 1.5:1 Diagnostic Criteria for Preeclampsia n SBP of 140 mm Hg or more or a DBP of 90 mm Hg or more on two occasions at least six hours apart after 20 weeks of gestation AND n Proteinuria 300 mg in a 24-hour urine specimen or 1+ or greater on urine dipstick testing of two random urine samples collected at least four hours apart. n A random urine protein/creatinine ratio 105-110 n Systolic BP 200 n Avoid rapid reduction in BP n Do not attempt to normalize BP n Goal is DBP 30 mL per hour, limit to 100 mL per hour. n The reason to treat is maternal, not fetal n May require ICU Characteristics of Severe HTN n Crises are associated with hypovolemia n Clinical assessment of hydration is inaccurate n Unprotected vascular beds are at risk, ie., uterine Key Steps Using Vasodilators n 250-500 cc of fluid, IV n Avoid multiple doses in rapid succession n Allow time for drug to work n Maintain LLD position n Avoid over treatment Acute Medical Therapy n Hydralazine n Labetalol n Nifedipine n Nitroprusside n Clonidine Hydralazine n Dose: 5-10 mg every 20 minutes n Onset: 10-20 minutes n Duration: 3-8 hours n Side effects: headache, flushing, tachycardia, lupus like symptoms n Mechanism: peripheral vasodilator Labetalol n Dose: 20 mg, then 40, then 80 every 20 minutes, for a total of 220mg n Onset: 1-2 minutes n Duration: 6-16 hours n Side effects: hypotension n Mechanism: Alpha and Beta blockade Nifedipine n Dose: 10 mg po, not sublingual n Onset: 5-10 minutes n Duration: 4-8 hours n Side effects: chest pain, headache, tachycardia n Mechanism: CA channel blockade Clonidine n Dose: 1 mg po n Onset: 10-20 minutes n Duration: 4-6 hours n Side effects: unpredictable, avoid rapid withdrawal n Mechanism: Alpha agonist, works centrally Nitroprusside n Dose: 0.2 0.8 mg/min IV n Onset: 1-2 minutes n Duration: 3-5 minutes n Side effects: cyanide accumulation, hypotension n Mechanism: direct vasodilator Seizure Prophylaxis n Magnesium sulfate n Loading dose of 4 to 6 g diluted in 100 mL of normal saline, given IV over 15 to 20 minutes, followed by a continuous infusion of 1-2 g per hour n Monitor urine output, RR and DTRs n With renal dysfunction, may require a lower dose Magnesium Sulfate n Is NOT a hypotensive agent n Works as a centrally acting anticonvulsant n Also blocks neuromuscular conduction n Serum levels: 4-7 mg/dL n Additional benefit of reducing the incidence of placental abruption Toxicity n Respiratory rate 12 n DTRs not detectable n Altered sensorium n Urine output 25-30 cc/hour n Antidote: 10 ml of 10% solution of calcium gluconate 1 g IV over 2 minutes. Eclampsia n New onset of seizures in a woman with pre- eclampsia. n Preceded by increasingly severe preeclampsia, or it may appear unexpectedly in a patient with minimally elevated blood pressure and no proteinuria. n Blood pressure is only mildly elevated in 30- 60% of women who develop eclampsia. n Occurs: Antepartum - 53%, intrapartum - 19%, or postpartum - 28% Treatment of Eclampsia n Protecting the patient and her airway n Place patient on left side and suction to minimize the risk of aspiration n Give oxygen n Avoid insertion of airways and padded tongue blades n IV access n Mag Sulfate 4-6 g IV bolus, if not effective, give another 2 g Alternate Anticonvulsants n Diazepam 5-10 mg IV n Sodium Amytal 100 mg IV n Pentobarbital 125 mg IV n Dilantin 500-1000 mg IV infusion After the Seizure n Assess maternal labs n Fetal well-being n Effect delivery n Transport when indicated n No need for immediate cesarean delivery Other Complications n Pulmonary edema n Oliguria n Persistent hypertension n DIC Pulmonary Edema n Fluid overload n Reduced colloid osmotic pressure n Occurs more commonly following delivery as colloid oncotic pressure drops further and fluid is mobilized Treatment of Pulmonary Edema n Avoid over-hydration n Restrict fluids n Lasix 10-20 mg IV n Usually no need for albumin or Hetastarch (Hespan) Oliguria n 25-30 cc per hour is acceptable n If less, small fluid boluses of 250-500 cc as needed n Lasix is not necessary n Postpartum diuresis is common n Persistent oliguria almost never requires a PA cath Persistent Hypertension n BP may remain elevated for several days n Diastolic BP less than 100 do not require treatment n By definition, preeclampsia resolves by 6 weeks Disseminated Intravascular Coagulopathy n Rarely occurs without abruption n Low platelets is not DIC n Requires replacement blood products and delivery Anesthesia Issues n Continuous lumbar epidural is preferred if platelets normal n Need adequate pre-hydration of 1000 cc n Level should always be advanced slowly to avoid low BP n Avoid spinal with severe disease SORT: KEY RECOMMENDATIONS FOR PRACTICE n In women without end-organ damage, chronic hypertension in pregnancy does not require treatment unless the patients blood pressure is persistently greater than 150 to 180/100 to 110 mm Hg. C n Calcium supplementation decreases the incidence of hypertension and preeclampsia, respectively, among all women (NNT = 11 and NNT = 20), women at high risk of hypertensive disorders (NNT = 2 and NNT = 6), and women with low calcium intake (NNT = 6 and NNT = 13). A n Low-dose aspirin (75 to 81 mg daily) has small to moderate benefits for the prevention of preeclampsia (NNT = 72), preterm delivery (NNT = 74), and fetal death (NNT = 243). The benefit of aspirin is greatest (NNT = 19) for prevention of preeclampsia in women at highest risk (previous severe preeclampsia, diabetes, chronic hypertension, renal disease, or autoimmune disease). B n For women with mild preeclampsia, delivery is generally not indicated until 37 to 38 weeks of gestation and should occur by 40 weeks. C n Magnesium sulfate is the treatment of choice for women with preeclampsia to prevent eclamptic seizures (NNT = 100) and placental abruption (NNT = 100). A n Intravenous labetalol or hydralazine may be used to treat severe hypertension in pregnancy because neither agent has demonstrated superior effectiveness. B n For managing severe preeclampsia between 24 and 34 weeks of gestation, the data are insufficient to determine whether an “interventionist“ approach (i.e., induction or cesarean delivery 12 to 24 hours after corticosteroid administration) is superior to expectant management. Expectant management, with close monitoring of the mother and fetus, reduces neonatal complications and stay in the newborn intensive care nursery. B n Magnesium sulfate is more effective than diazepam (Valium; NNT = 8) or phenytoin (Dilantin; NNT = 8) in preventing recurrent eclamptic seizures. A Quiz n Which one of the following statements about preeclampsia is correct? A. Magnesium sulfate is the treatment of choice to prevent eclamptic seizures. B. Diazepam (Valium) is more effective than magnesium sulfate in preventing recurrent eclamptic seizures. C. Low-dose aspirin is beneficial for the prevention of preeclampsia in low-risk women. D. An “interventionist“ approach is superior to expectant management for severe preeclampsia between 24 and 34 weeks of gestation. n Which of the following agents is/are used to treat a 30-year-old woman (gravida 1, para 0) at 19 weeks of gestation who has had a blood pressure measurement of 160/115 mm Hg on two occasions during her current pregnancy? A. Methyldopa (Aldomet; brand no longer available in the U