Hypertension in pregnancy Presented by Dr A Shakor MBCh

Hypertension in pregnancy Presented by Dr A/Shakor MBCh. B GEZIRA UNIVERSITY -SUDAN Head of Anatomy Department Somali International University

o. BJecti. Ves 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 discuss the effects of hypertension on the mother and fetus.

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

Hypertensive Disease Associated with Pregnancy v. Chronic Hypertension. v. Gestational Hypertension. v. Preeclampsia. v. Eclampsia. v. HELLP Syndrome.

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

Hypertensive Disease Associated with Pregnancy 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 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

Preeclampsia vs. Severe Preeclampsia Criteria for Preeclampsia Previously normotensive woman > 140 mm. Hg systolic > 90 mm. Hg diastolic Proteinuria > 300 mg in 24 hour collection Nondependent edema Criteria for Severe Preclampsia 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 m. L in 24 hours Cerebral or visual distrubances (headache) Pulmonary edema or cyanosis Epigastric or RUQ pain Evidence of hepatic dysfunction Thrombocytopenia Intrauterine growth restriciton (IUGR)

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

risk Factors FACTOR RISK RATIO Nulliparity Age > 40 3: 1 African American 1. 5: 1 Chronic hypertension 10: 1 Renal disease 20: 1 Antiphospholipid syndrome 10: 1

Hypertensive Disease Associated with Pregnancy 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 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

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

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

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

pathophysiology 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 Vasospasm Uterine vessels Hemostasis ◦ Increase platelet activation resulting in consumption ◦ Increased endothelial fibronectin levels ◦ Decreased antithrombin III and α 2 -antiplasmin levels ◦ Allows for microthrombi development with resultant increase in endothelial damage Prostanoid balance Endothelium-derived factors Lipid peroxide, free radicals and antioxidants

pathophysiology Vasospasm Uterine vessels Hemostasis Prostanoid balance ◦ TXA 2 promotes: Vasoconstriction Platelet aggregation Endothelium-derived factors Lipid peroxide, free radicals and antioxidants

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

pathophysiologic changes 1. 2. 3. 4. 5. 6. Cardiovascular effects. Hematologic effects. Neurologic effects. Pulmonary effects. Renal effects. Fetal effects.

pathophysiologic changes Cardiovascular effects ◦ Hypertension ◦ Increased cardiac output ◦ Increased systemic vascular resistance Hematologic effects Neurologic effects Pulmonary effects Renal effects Fetal effects

pathophysiologic changes Cardiovascular effects Hematologic effects ◦ Hypovolemia. ◦ Elevated hematocrit ◦ Thrombocytopenia ◦ hemolytic anemia. ◦ Low oncotic pressure Neurologic effects Pulmonary effects Renal effects Fetal effects

pathophysiologic changes Cardiovascular effects Hematologic effects Neurologic effects: ◦ Hyperreflexia ◦ Headache ◦ Cerebral edema ◦ Seizures Pulmonary effects Renal effects Fetal effects

pathophysiologic changes Cardiovascular effects Hematologic effects Neurologic effects Pulmonary effects ◦ Pulmonary edema Renal effects Fetal effects

pathophysiologic changes Cardiovascular effects Hematologic effects Neurologic effects Pulmonary effects Renal effects ◦ Decreased glomerular filtration rate ◦ Proteinuria ◦ Oliguria ◦ Acute tubular necrosis Fetal effects

Pathophysiologic Changes 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

Management: A. B. C. D. E. F. The ultimate cure is delivery. Assess gestational age. Assess cervix. Fetal well-being. Laboratory assessment. Rule out severe disease!!

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

Mild Gestational HTN not at Term: A. B. C. D. E. F. Rule out severe disease Conservative management Serial labs Twice weekly visits Antenatal fetal surveillance Outpatient versus inpatient

Indications for Delivery ØWorsening BP. ØNon-reassuring fetal condition. ØDevelopment of severe PIH. ØFetal lung maturity. ØFavorable cervix.

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

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

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

Acute Medical Therapy v. Hydralazine v. Labetalol v. Nifedipine v. Nitroprusside v. Diazoxide v. Clonidine

Hydralazine ØDose: 5 -10 mg every 20 minutes ØOnset: 10 -20 minutes ØDuration: 3 -8 hours ØSide effects: headache, tachycardia. ØMechanism: peripheral vasodilator

Labetalol ØDose: 20 mg, then 40, then 80 every 20 minutes, for a total of 220 mg ØOnset: 1 -2 minutes ØDuration: 6 -16 hours ØSide effects: hypotension ØMechanism: Alpha and Beta block

Nifedipine ØDose: 10 mg , not sublingual ØOnset: 5 -10 minutes ØDuration: 4 -8 hours ØSide effects: chest pain, headache, tachycardia ØMechanism: CA channel block

Clonidine ØDose: 1 mg po ØOnset: 10 -20 minutes ØDuration: 4 -6 hours ØSide effects: unpredictable, avoid rapid withdrawal ØMechanism: Alpha agonist, works centrally

Nitroprusside ØDose: 0. 2 – 0. 8 mg/min IV ØOnset: 1 -2 minutes ØDuration: 3 -5 minutes ØSide effects: cyanide accumulation, hypotension ØMechanism: direct vasodilator

seizure prophylaxis v. Magnesium sulfate v 4 -6 g bolus v 1 -2 g/hour v. Monitor urine output. v. With renal dysfunction, may require a lower dose

Magnesium Sulfate. v. Is not a hypotensive agent v. Works as a centrally acting anticonvulsant v. Also blocks neuromuscular conduction

Treatment of Eclampsia Few people die of seizures Protect patient Avoid insertion of airways and padded tongue blades IV access MGSO 4

t. He First t. Hing to Do at a sei. Zure is to take your o. Wn pu. Lse!

Alternate Anticonvulsants 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

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

Other Complications Pulmonary edema Oliguria Persistent hypertension DIC

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

Treatment of Pulmonary Edema Avoid over-hydration Restrict fluids Lasix 10 -20 mg IV Usually no need for albumin.

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

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

Anesthesia Issues 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

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

HELLP Syndrome 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

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

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