PREGNANCY INDUCED HYPERTENSION PowerPoint Presentation

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Hypertension in Pregnancy Teresa G. Berg, M.D. Maternal-Fetal Medicine University Medical Associates M3 Lecture Materials

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Be able to define hypertension in relationship to pregnancy Be able to classify hypertensive diseases in pregnant women Be able to list criteria for the diagnosis of preeclampsia Be able to list criteria for the diagnosis of severe preeclampsia/HELLP syndrome Be able to discuss current management considerations Understand and discuss the effects of hypertension on the mother and fetus OBJECTIVES

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Sustained BP elevation of 140/90 or greater Proper cuff size Measurement taken while seated Arm at the level of the heart Use 5th Korotkoff sound Hypertension

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Chronic Hypertension Gestational Hypertension Preeclampsia Eclampsia HEELP Syndrome Hypertensive Disease Associated with Pregnancy

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Chronic Hypertension Diagnosed before the 20th week or present before the pregnancy Mild hypertension > 140-180 mmHg systolic > 90-100 mmHg diastolic Gestational Hypertension Preeclampsia Eclampsia HEELP Syndrome Hypertensive Disease Associated with Pregnancy

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Chronic Hypertension Gestational Hypertension Criteria Develops after 20 weeks of gestation Proteinuria is absent Blood pressures return to normal postpartum Morbidity is directly related to the degree of hypertension Preeclampsia Eclampsia HEELP Syndrome Hypertensive Disease Associated with Pregnancy

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Overlap/Disease Progression 25%

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Chronic Hypertension Gestational Hypertension Preeclampsia Criteria Develops after 20 weeks Blood pressure elevated on two occasions at least 6 hours apart Associated with proteinuria and edema May occur less than 20 weeks with gestational trophoblastic neoplasia Eclampsia HEELP Syndrome Hypertensive Disease Associated with Pregnancy

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Preeclampsia vs. Severe Preeclampsia Criteria for Preeclampsia Criteria for Severe Preclampsia Previously normotensive woman > 140 mmHg systolic > 90 mmHg diastolic Proteinuria > 300 mg in 24 hour collection Nondependent edema BP > 160 systolic or >110 diastolic > 5 gr of protein in 24 hour urine or > 3+ on 2 dipstick urines greater than 4 hours apart Oliguria < 500 mL in 24 hours Cerebral or visual distrubances (headache, scotomata) Pulmonary edema or cyanosis Epigastric or RUQ pain Evidence of hepatic dysfunction Thrombocytopenia Intrauterine growth restriciton (IUGR)

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Risk Factors for Preeclampsia Nulliparity Multifetal gestations Maternal age over 35 Preeclampsia in a previous pregnancy Chronic hypertension Pregestational diabetes Vascular and connective tissue disorders Nephropathy Antiphospholipid syndrome Obesity African-American race

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Risk Factors

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Chronic Hypertension Gestational Hypertension Preeclampsia Eclampsia Diagnosis of preeclampsia Presence of convulsions not explained by a neurologic disorder Grand mal seizure activity Occurs in 0.5 to 4% or patients with preeclampsia HEELP Syndrome Hypertensive Disease Associated with Pregnancy

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Chronic Hypertension Gestational Hypertension Preeclampsia Eclampsia HELLP Syndrome A distinct clinical entity with: Hemolysis, Elevated Liver enzymes, Low Platelets Occurs in 4 to 12 % of patients with severe preeclampsia Microangiopathic hemolysis Thrombocytopenia Hepatocellular dysfunction Hypertensive Disease Associated with Pregnancy

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Hypertension affects 12 to 22% of pregnant patients Hypertensive disease is directly responsible for approximately 20% of maternal mortality in the United State Morbidity and Mortality from Hypertensive Disease

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Vasospasm Uterine vessels Hemostasis Prostanoid balance Endothelium-derived factors Lipid peroxide, free radicals and antioxidants Pathophysiology

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Vasospasm Predominant finding in gestational hypertension and preeclampsia Uterine vessels Hemostasis Prostanoid balance Endothelium-derived factors Lipid peroxide, free radicals and antioxidants Pathophysiology

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Vasospasm Uterine vessels Inadequate maternal vascular response to trophoblastic mediated vascular changes Endothelial damage Hemostasis Prostanoid balance Endothelium-derived factors Lipid peroxide, free radicals and antioxidants Pathophysiology

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Vasospasm Uterine vessels Hemostasis Increase platelet activation resulting in consumption Increased endothelial fibronectin levels Decreased antithrombin III and α2-antiplasmin levels Allows for microthrombi development with resultant increase in endothelial damage Prostanoid balance Endothelium-derived factors Lipid peroxide, free radicals and antioxidants Pathophysiology

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Vasospasm Uterine vessels Hemostasis Prostanoid balance Prostacyclin (PGI2):Thromboxane (TXA2) balance shifted to favor TXA2 TXA2 promotes: Vasoconstriction Platelet aggregation Endothelium-derived factors Lipid peroxide, free radicals and antioxidants Pathophysiology

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Vasospasm Uterine vessels Hemostasis Prostanoid balance Endothelium-derived factors Nitric oxide is decreased in patients with preeclampsia As this is a vasodilator, this may result in vasoconstriction Lipid peroxide, free radicals and antioxidants Pathophysiology

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Vasospasm Uterine vessels Hemostasis Prostanoid balance Endothelium-derived factors Lipid peroxide, free radicals and antioxidants Increased in preeclampsia Have been implicated in vascular injury Pathophysiology

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Cardiovascular effects Hematologic effects Neurologic effects Pulmonary effects Renal effects Fetal effects Pathophysiologic Changes

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Cardiovascular effects Hypertension Increased cardiac output Increased systemic vascular resistance Hematologic effects Neurologic effects Pulmonary effects Renal effects Fetal effects Pathophysiologic Changes

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Cardiovascular effects Hematologic effects Volume contraction/Hypovolemia Elevated hematocrit Thrombocytopeniz Microangiopathic hemolytic anemia Third spacing of fluid Low oncotic pressure Neurologic effects Pulmonary effects Renal effects Fetal effects Pathophysiologic Changes

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Cardiovascular effects Hematologic effects Neurologic effects Hyperreflexia Headache Cerebral edema Seizures Pulmonary effects Renal effects Fetal effects Pathophysiologic Changes

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Cardiovascular effects Hematologic effects Neurologic effects Pulmonary effects Capillary leak Reduced colloid osmotic pressure Pulmonary edema Renal effects Fetal effects Pathophysiologic Changes

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Cardiovascular effects Hematologic effects Neurologic effects Pulmonary effects Renal effects Decreased glomerular filtration rate Glomerular endotheliosis Proteinuria Oliguria Acute tubular necrosis Fetal effects Pathophysiologic Changes

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Decreased glomerular filtration rate Glomerular endotheliosis Proteinuria Oliguria Acute tubular necrosis Renal Effects

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Cardiovascular effects Hematologic effects Neurologic effects Pulmonary effects Renal effects Fetal effects Placental abruption Fetal growth restriction Oligohydramnios Fetal distress Increased perinatal morbidity and mortality Pathophysiologic Changes

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The ultimate cure is delivery Assess gestational age Assess cervix Fetal well-being Laboratory assessment Rule out severe disease!! Management

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Delivery is always a reasonable option if term If cervix is unfavorable and maternal disease is mild, expectant management with close observation is possible Gestational HTN at Term

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Rule out severe disease Conservative management Serial labs Twice weekly visits Antenatal fetal surveillance Outpatient versus inpatient Mild Gestational HTN not at Term

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Worsening BP Nonreassuring fetal condition Development of severe PIH Fetal lung maturity Favorable cervix Indications for Delivery

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No contraindication to prostaglandin agents If < 32 weeks, consider cesarean When favorable, oxytocin Unfavorable Cervix

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Fetal monitoring IV access IV hydration The reason to treat is maternal, not fetal May require ICU Hypertensive Emergencies

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Diastolic BP > 105-110 Systolic BP > 200 Avoid rapid reduction in BP Do not attempt to normalize BP Goal is DBP < 105 not < 90 May precipitate fetal distress Criteria for Treatment

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Crises are associated with hypovolemia Clinical assessment of hydration is inaccurate Unprotected vascular beds are at risk, eg, uterine Characteristics of Severe HTN

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250-500 cc of fluid, IV Avoid multiple doses in rapid succession Allow time for drug to work Maintain LLD position Avoid over treatment Key Steps Using Vasodilators

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Hydralazine Labetalol Nifedipine Nitroprusside Diazoxide Clonidine Acute Medical Therapy

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Dose: 5-10 mg every 20 minutes Onset: 10-20 minutes Duration: 3-8 hours Side effects: headache, flushing, tachycardia, lupus like symptoms Mechanism: peripheral vasodilator Hydralazine

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Dose: 20mg, then 40, then 80 every 20 minutes, for a total of 220mg Onset: 1-2 minutes Duration: 6-16 hours Side effects: hypotension Mechanism: Alpha and Beta block Labetalol

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Dose: 10 mg po, not sublingual Onset: 5-10 minutes Duration: 4-8 hours Side effects: chest pain, headache, tachycardia Mechanism: CA channel block Nifedipine

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Dose: 1 mg po Onset: 10-20 minutes Duration: 4-6 hours Side effects: unpredictable, avoid rapid withdrawal Mechanism: Alpha agonist, works centrally Clonidine

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Dose: 0.2 – 0.8 mg/min IV Onset: 1-2 minutes Duration: 3-5 minutes Side effects: cyanide accumulation, hypotension Mechanism: direct vasodilator Nitroprusside

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Magnesium sulfate 4-6 g bolus 1-2 g/hour Monitor urine output and DTR’s With renal dysfunction, may require a lower dose Seizure Prophylaxis

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Is not a hypotensive agent Works as a centrally acting anticonvulsant Also blocks neuromuscular conduction Serum levels: 6-8 mg/dL Magnesium Sulfate

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Respiratory rate < 12 DTR’s not detectable Altered sensorium Urine output < 25-30 cc/hour Antidote: 10 ml of 10% solution of calcium gluconate 1 v over 3 minutes Toxicity

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Few people die of seizures Protect patient Avoid insertion of airways and padded tongue blades IV access MGSO4 4-6 bolus, if not effective, give another 2 g Treatment of Eclampsia

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THE FIRST THING TO DO AT A SEIZURE IS TO TAKE YOUR OWN PULSE!

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Have not been shown to be as efficacious as magnesium sulfate and may result in sedation that makes evaluation of the patient more difficult Diazepam 5-10 mg IV Sodium Amytal 100 mg IV Pentobarbital 125 mg IV Dilantin 500-1000 mg IV infusion Alternate Anticonvulsants

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Assess maternal labs Fetal well-being Effect delivery Transport when indicated No need for immediate cesarean delivery After the Seizure

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Pulmonary edema Oliguria Persistent hypertension DIC Other Complications

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Fluid overload Reduced colloid osmotic pressure Occurs more commonly following delivery as colloid oncotic pressure drops further and fluid is mobilized Pulmonary Edema

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Avoid over-hydration Restrict fluids Lasix 10-20 mg IV Usually no need for albumin or Hetastarch (Hespan) Treatment of Pulmonary Edema

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25-30 cc per hour is acceptable If less, small fluid boluses of 250-500 cc as needed Lasix is not necessary Postpartum diuresis is common Persistent oliguria almost never requires a PA cath Oliguria

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BP may remain elevated for several days Diastolic BP less than 100 do not require treatment By definition, preeclampsia resolves by 6 weeks Persistent Hypertension

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Rarely occurs without abruption Low platelets is not DIC Requires replacement blood products and delivery Disseminated Intravascular Coagulopathy

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Continuous lumbar epidural is preferred if platelets normal Need adequate pre-hydration of 1000 cc Level should always be advanced slowly to avoid low BP Avoid spinal with severe disease Anesthesia Issues

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He-hemolysis EL-elevated liver enzymes LP-low platelets HELLP Syndrome

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Is a variant of severe preeclampsia Platelets < 100,000 LFT’s - 2 x normal May occur against a background of what appears to be mild disease HELLP Syndrome

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Controversial Steroids Requires tertiary care Must have stable labs and reassuring fetal status May use antihypertensives Conservative Management

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Low dose ASA ineffective in patients at low risk Calcium supplementation is ineffective (2.0 g of calcium gluconate per day) No compelling evidence that either are harmful Recent study done with antioxidant (1,000mg VitC and 400mg VitE). Small study that needs to be confirmed. Prevention

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Criteria for diagnosis Laboratory and fetal assessment Magnesium sulfate seizure prophylaxis Timing and place of delivery SUMMARY