Presentation on theme: "MODULE 3 CHAPTER 2 E PLAN Diagnosis and classificaton of hypertension in pregnancy Pathophysiology Evaluation of newly diagnosed Hypertension - Gestational."— Presentation transcript:
MODULE 3 CHAPTER 2 E
PLAN Diagnosis and classificaton of hypertension in pregnancy Pathophysiology Evaluation of newly diagnosed Hypertension - Gestational Vs Preeclampsia - Mild or severe - Measure protein excretion - Look for high risk symptoms - Perform lab evaluation - Assess fetal wellbeing Management Conclusion
DIAGNOSIS AND CLASSIFICATION
Introduction Most common medical complication of pregnancy 5-10 % of gestations in India. In 2000, the National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy defined four categories of hypertension in pregnancy: – Chronic hypertension – Gestational hypertension – Preeclampsia – Preeclampsia superimposed on chronic hypertension
MEASUREMENT TECHNIQUE In seated position- Relaxed Use correct cuff size Avoid Vena-caval compression when supine – left lateral decubitus Avoid terminal digit preference– Read off to the nearest 2mm of Hg. Diastolic pressure is at K V If K sounds heard till zero both K 4 and 5 levels to be mentioned eg 140/70/0
Chronic Hypertension Defined 1.BP measurement of 140/90 mm Hg or more on two occasions six hours apart 2.Before 20 weeks of gestation OR Persisting beyond 12 weeks postpartum
Gestational Hypertension Formerly called PIH (Pregnancy Induced HTN) HTN without proteinuria occurring after 20 weeks gestation and returning to normal within 12 weeks after delivery. 50% of women diagnosed with gestational hypertension between 24 and 35 weeks develop preeclampsia.
Older Criteria for Gestational HTN 30/15 increase in BP over baseline levels No longer appropriate 73% of patients will exceed 30 mm systolic and 57% will exceed 20 mm diastolic
Preeclampsia New onset hypertension with proteinuria after 20 weeks gestation. Resolves by 6 weeks postpartum. 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 FACTORRISK RATIO Renal disease20:1 Chronic hypertension10:1 Antiphospholipid syndrome 10:1 Family history of PIH5:1 Twin gestation4:1 Nulliparity3:1 Age > 403:1 Diabetes mellitus2:1 African American1.5:1
Chronic Vs pregnancy induced hypertension Gestational Vs preeclampsia Mild Vs severe gestational hypertension Mild Vs severe preeclampsia Preclampsia Vs eclampsia
GESTATIONAL VS PREECLAMPSIA GESTATIONAL Primi not a strong RF Recurrent risk 20-47% Total blood and plasma volume not low Proteinuria absent Odema absent PREECLAMPSIA Primi Recuurent risk 5% Total blood and plasma volume low Proteinuria present Odema present
GESATATIONAL HYPERTENSION MILD VS SEVERE MILD SBP DBP SEVERE SBP >160 DBP>110 THERE IS NO MODERATE HYPERTENSION IN PREGNANCY
Eclampsia New onset of seizures in a woman with pre- eclampsia. Preceded by increasingly severe preeclampsia, or it may appear unexpectedly in a patient with minimally elevated blood pressure and no proteinuria. Blood pressure is only mildly elevated in 30-60% of women who develop eclampsia. Occurs: Antepartum - 53%, intrapartum - 19%, or postpartum - 28%
Diagnostic Criteria for Preeclampsia 1.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 2.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. A random urine protein/creatinine ratio 0.7 indicates definite proteinuria. Generalized edema (affecting the face and hands) is often present in patients with preeclampsia but is not a diagnostic criterion.
Headache Visual disturbance Dyspnoea Chest pain Right upper quadrant pain Low urine output Severe odema Pregant woman with these Symptoms should be Suspected to have preeclampsia Even when there is no proteinuria
MATERNAL INVESTIGATION Full blood count:- Haemoglobin, hematocrit, platelet count and blood film if there is any evidence of hemolysis Biochemistry:Urea, Creatinine, electrolytes, and uric acid, LFT 24 hr. urine save: total protein assessment +- catecholamines Others:ANA, anti-cardiolipin, lupus anticoagulant, for early onset PET ( ie <32 weeks)
HELLP Syndrome Is a variant of severe preeclampsia Occurs in up to 20% of pregnancies complicated by severe preeclampsia. Variable clinical presentation; 12 to 18% are normotensive and 13% do not have proteinuria. At diagnosis, 30% of women are postpartum, 18% are term, and 52% are preterm.
HELLP Syndrome Common presenting complaints are RUQ or epigastric pain, N/V, malaise or nonspecific symptoms suggesting an acute viral syndrome. Any patient with these symptoms or signs of preeclampsia should be evaluated with CBC, platelet count, and liver enzymes. When platelet count < 50,000/mm3 or active bleeding occurs, coagulation studies needed to R/O DIC.
FETAL ASSESSMENT Ultrasound estimation of fetal size:head and abdominal circumferences and the ratio between the two Biophysical profile: fetal movement, tone, breathing movements & liquor volume + fetal heart rate assessment Cardiotocography:Standard or computerised Doppler ultrasound: uterine arteries, umblical arteries, +- fetal regional studies Others: amniocentesis, fetal blood sample
UMBILICAL ARTERY DOPPLER NORMAL HIGH RISK
??????????? WHEN TO START WHAT LEVEL TO START WHAT LEVEL TO BE ACHIEVED WHAT IS FETAL OUTCOME WHICH IS IDEAL DRUG WHAT SPEED WHEN TO START SECOND DRUG
Blood pressure goal A reasonable goal of therapy in women without end-organ damage is systolic pressure between 140 and 150 mmHg and diastolic pressure between 90 and 100 mmHg. Overly aggressive blood pressure reduction could be harmful. One analysis reported that a 10 mmHg fall in mean arterial pressure was associated with a 176 g decrease in birth weight. This effect was unrelated to the type of hypertension or choice of medication.
Criteria for Treatment Diastolic BP > Systolic BP > 160 Avoid rapid reduction in BP Do not attempt to normalize BP Goal is DBP < 105 not < 90 May precipitate fetal distress
Gestational HTN at Term Delivery is always a reasonable option if term If cervix is unfavorable and maternal disease is mild, expectant management with close observation is possible
Mild Gestational HTN Not at Term / Rule out severe disease Conservative management Serial labs Twice weekly visits Antenatal fetal surveillance Outpatient versus inpatient Ideal time of delivery is 40 weeks Anti hypertensive therapy in young patients with low pre pregancy BP with high risk symptoms
Management of Preeclampsia The ultimate cure is DELIVERY. Assess gestational age Assess cervix Fetal well-being Laboratory assessment Rule out severe disease
Indications for Delivery in Preeclampsia Maternal indications – Gestational age of 38 weeks or greater – Platelet count below 100,000 – Progressive deterioration of hepatic or renal function – Suspected placental abruption – Persistent severe headache or visual changes – Persistent severe epigastric pain, nausea, or vomiting – Eclampsia
Indications for Delivery in Preeclampsia Fetal indications – Severe intrauterine growth restriction – Nonreassuring fetal surveillance – Oligohydramnios
ANTI HYPERTENSIVE DRUGS
Hypertensive Emergencies Fetal monitoring IV access IV hydration to maintain urine output > 30 mL per hour, limit to 100 mL per hour. The reason to treat is maternal, not fetal May require ICU
Characteristics of Severe HTN Crises are associated with hypovolemia Clinical assessment of hydration is inaccurate Unprotected vascular beds are at risk, ie., uterine
Key Steps Using Vasodilators 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 Hydralazine Labetalol Nifedipine Nitroprusside Clonidine
Hydralazine Dose: 5-10 mg every 20 minutes Onset: minutes Duration: 3-8 hours Side effects: headache, flushing, tachycardia, lupus like symptoms Mechanism: peripheral vasodilator
Labetalol Dose: 20 mg, 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 blockade
Nifedipine Dose: 10 mg po, not sublingual Onset: 5-10 minutes Duration: 4-8 hours Side effects: chest pain, headache, tachycardia Mechanism: CA channel blockade
Clonidine Dose: 1 mg po Onset: minutes Duration: 4-6 hours Side effects: unpredictable, avoid rapid withdrawal Mechanism: Alpha agonist, works centrally
Nitroprusside Dose: 0.2 – 0.8 mg/min IV Onset: 1-2 minutes Duration: 3-5 minutes Side effects: cyanide accumulation, hypotension Mechanism: direct vasodilator
Seizure Prophylaxis Magnesium sulfate 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 Monitor urine output, RR and DTR’s With renal dysfunction, may require a lower dose
Treatment of Eclampsia Protecting the patient and her airway Place patient on left side and suction to minimize the risk of aspiration Give oxygen Avoid insertion of airways and padded tongue blades IV access Mag Sulfate 4-6 g IV bolus, if not effective, give another 2 g
Magnesium Sulfate Is NOT a hypotensive agent Works as a centrally acting anticonvulsant Also blocks neuromuscular conduction Serum levels: 4-7 mg/dL Additional benefit of reducing the incidence of placental abruption
Toxicity Respiratory rate < 12 DTR’s not detectable Altered sensorium Urine output < cc/hour Antidote: 10 ml of 10% solution of calcium gluconate 1 g IV over 2 minutes.
Alternate Anticonvulsants Diazepam 5-10 mg IV Sodium Amytal 100 mg IV Pentobarbital 125 mg IV Dilantin mg IV infusion
After the Seizure Assess maternal labs Fetal well-being Effect delivery Transport when indicated No need for immediate cesarean delivery
Other Complications Pulmonary edema Oliguria Persistent hypertension DIC
Pulmonary Edema Fluid overload Reduced colloid osmotic pressure 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 mg IV Usually no need for albumin or Hetastarch (Hespan)
Oliguria cc per hour is acceptable If less, small fluid boluses of cc as needed Lasix is not necessary Postpartum diuresis is common Persistent oliguria almost never requires a PA cath
Persistent Hypertension BP may remain elevated for several days Diastolic BP less than 100 do not require treatment By definition, preeclampsia resolves by 6 weeks
Disseminated Intravascular Coagulopathy Rarely occurs without abruption Low platelets is not DIC Requires replacement blood products and delivery
Prevention of Preeclampsia Routine supplementation with calcium, magnesium, omega-3 fatty acids, or antioxidant vitamins is ineffective. Calcium reduces the risk of developing preeclampsia in high-risk women and those with low dietary calcium intake. Low-dose aspirin (75 to 81 mg per day) is effective for women at increased risk of preeclampsia, NNT = 69 ; NNT = 227 to prevent one fetal death. Low-dose aspirin is effective for women at highest risk from previous severe preeclampsia, diabetes, chronic hypertension, or renal or autoimmune disease, NNT = 18.
LONG TERM MATERNAL RISKS The absolute risk that a woman with or without a history of preeclampsia would develop one of these cardiovascular events (hypertension, CAD,stroke, venous thrombo embolism) at age 50 to 59 years was estimated to be 17.8 and 8.3 percent, respectively. Further review of these data show that women with early onset/severe preeclampsia, recurrent preeclampsia, gestational hypertension, or preeclampsia with onset as a multipara appear to be at highest risk of cardiovascular disease later in life, including during the premenopausal period
Chronic Hypertension Treatment of mild to moderate chronic hypertension neither benefits the fetus nor prevents preeclampsia. Excessively lowering blood pressure may result in decreased placental perfusion and adverse perinatal outcomes. 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 Methyldopa, labetalol, and nifedipine most common oral agents. AVOID: ACEI and ARBs, atenolol, thiazide diuretics Women in active labor with uncontrolled severe chronic hypertension require treatment with intravenous labetalol or hydralazine.
The cure is achieved by delivery, which removes the diseased tissue—the placenta. In short, the need is to deliver before it is too late. To achieve this apparently simple end, the clinician must detect the symptomless prodromal condition by screening all pregnant women, admit to hospital those with advanced preeclampsia so as to keep track of an unpredictable situation, and time preemptive delivery to maximize the safety of mother and baby. --REDMAN AND ROBERTS