Pregnancy induced Hypertension & eclampsia - Clinicals, Diagnosis, and Management

Obstetrics

Clinicals - History

Fact Explanation
Headache Occurs due to hypertension.
Gestational hypertension is usually defined as having a blood pressure higher than 140/90 measured on two separate occasions, more than 6 hours apart, without the presence of protein in the urine and diagnosed after 20 weeks of gestation
Preeclampsia (PE), defined as new onset hypertension and proteinuria, is a severe multi-system disorder affecting 3–6% of human pregnancies
Severe pre eclampsia -usually frontal but may be occipital. It is due to cerebral oedema and hypertension
Headache
Occurs due to hypertension.
Gestational hypertension is usually defined as having a blood pressure higher than 140/90 measured on two separate occasions, more than 6 hours apart, without the presence of protein in the urine and diagnosed after 20 weeks of gestation
Preeclampsia (PE), defined as new onset hypertension and proteinuria, is a severe multi-system disorder affecting 3–6% of human pregnancies
Severe pre eclampsia -usually frontal but may be occipital. It is due to cerebral oedema and hypertension
Visual problems, frothy urine, headache, swelling of hands and feet Due to Preeclampsia which is a multiorgan disease process of unknown etiology characterized by the development of hypertension and proteinuria (>300 mg of protein in a 24-hour urine sample) after 20 weeks of gestation

Frothy urine occurs due to protein in urine.
Edema occurs due to imbalances of the starling forces caused by protein loss

Theories of pathogenesis:
Abnormal placental implantation (defects in trophoblasts and spiral arterioles),
Angiogenic factors (increased sFlt-1, decreased placental growth factor levels),
Cardiovascular maladaptation and vasoconstriction ,
Genetic predisposition (maternal, paternal, thrombophilias) ,
Immunologic intolerance between fetoplacental and maternal tissue ,
Platelet activation ,
Vascular endothelial damage or dysfunction
Visual problems, frothy urine, headache, swelling of hands and feet
Due to Preeclampsia which is a multiorgan disease process of unknown etiology characterized by the development of hypertension and proteinuria (>300 mg of protein in a 24-hour urine sample) after 20 weeks of gestation

Frothy urine occurs due to protein in urine.
Edema occurs due to imbalances of the starling forces caused by protein loss

Theories of pathogenesis:
Abnormal placental implantation (defects in trophoblasts and spiral arterioles),
Angiogenic factors (increased sFlt-1, decreased placental growth factor levels),
Cardiovascular maladaptation and vasoconstriction ,
Genetic predisposition (maternal, paternal, thrombophilias) ,
Immunologic intolerance between fetoplacental and maternal tissue ,
Platelet activation ,
Vascular endothelial damage or dysfunction
Antiphospholipid antibody syndrome, Chronic hypertension, chronic renal failure, Elevated body mass index, Maternal age older than 40 years, Multiple gestation, Nulliparity, Preeclampsia in a previous pregnancy (particularly if severe or before 32 weeks of gestation), family history of pre eclampsia, Pregestational diabetes mellitus Preeclampsia is more common among women likely to have a large placenta, such as those with multiple pregnancies, and among women with medical conditions associated with microvascular disease, such as diabetes, hypertension, and collagen vascular disease. Other risk factors include genetic susceptibility, increased parity, and older maternal age Antiphospholipid antibody syndrome, Chronic hypertension, chronic renal failure, Elevated body mass index, Maternal age older than 40 years, Multiple gestation, Nulliparity, Preeclampsia in a previous pregnancy (particularly if severe or before 32 weeks of gestation), family history of pre eclampsia, Pregestational diabetes mellitus
Preeclampsia is more common among women likely to have a large placenta, such as those with multiple pregnancies, and among women with medical conditions associated with microvascular disease, such as diabetes, hypertension, and collagen vascular disease. Other risk factors include genetic susceptibility, increased parity, and older maternal age
Seizures Eclampsia is when tonic-clonic seizures appear in a pregnant woman with high blood pressure and proteinuria Seizures
Eclampsia is when tonic-clonic seizures appear in a pregnant woman with high blood pressure and proteinuria
Abdominal pain Right upper quadrant tenderness is present in as many as 90 percent of affected women with HELLP syndrome.
The three chief abnormalities found in HELLP syndrome are hemolysis, elevated liver enzyme levels and a low platelet count
Abdominal pain
Right upper quadrant tenderness is present in as many as 90 percent of affected women with HELLP syndrome.
The three chief abnormalities found in HELLP syndrome are hemolysis, elevated liver enzyme levels and a low platelet count

Clinicals - Examination

Fact Explanation
High blood pressure Blood pressure should be measured at each prenatal visit with an appropriately sized cuff and the patient in a seated position. Diagnostic criteria for preeclampsia are systolic blood pressure of 140 mmHg or more or a diastolic blood pressure of 90 mm Hg or more on two occasions at least four hours apart High blood pressure
Blood pressure should be measured at each prenatal visit with an appropriately sized cuff and the patient in a seated position. Diagnostic criteria for preeclampsia are systolic blood pressure of 140 mmHg or more or a diastolic blood pressure of 90 mm Hg or more on two occasions at least four hours apart
Edema Edema occurs due to imbalances of the starling forces caused by protein loss (pre eclampsia) Edema
Edema occurs due to imbalances of the starling forces caused by protein loss (pre eclampsia)
Abdominal examination Right upper quadrant tenderness is present in as many as 90 percent of affected women with HELLP syndrome
Symphisio fundal height may be reduced due to intra uterine growth restriction
Abdominal examination
Right upper quadrant tenderness is present in as many as 90 percent of affected women with HELLP syndrome
Symphisio fundal height may be reduced due to intra uterine growth restriction
Hyper reflexia Occurs in severe pre eclampsia due to multi system failure Hyper reflexia
Occurs in severe pre eclampsia due to multi system failure

Investigations - Diagnosis

Fact Explanation
Blood pressure Hypertension in pregnancy is defined as a systolic BP ≥ 140 mm Hg and a diastolic BP ≥ 90 mm Hg on two separate measurements at least 4–6 hours apart without the presence of protein in the urine and diagnosed after 20 weeks of gestation
Preeclampsia is characterized by the development of hypertension and proteinuria after 20 weeks of gestation
Severe pre eclampsia - Blood pressure ≥ 160 mm Hg systolic or 110 mm Hg diastolic on two occasions at least six hours apart during bed rest
Blood pressure
Hypertension in pregnancy is defined as a systolic BP ≥ 140 mm Hg and a diastolic BP ≥ 90 mm Hg on two separate measurements at least 4–6 hours apart without the presence of protein in the urine and diagnosed after 20 weeks of gestation
Preeclampsia is characterized by the development of hypertension and proteinuria after 20 weeks of gestation
Severe pre eclampsia - Blood pressure ≥ 160 mm Hg systolic or 110 mm Hg diastolic on two occasions at least six hours apart during bed rest
Protein in urine Pre eclampsia - proteinuria (>300 mg of protein in a 24-hour urine sample)
Severe pre eclampsia- Proteinuria ≥ 5 g in a 24-hour urine specimen or 3+ or greater on two random urine specimens collected at least four hours apart
Protein in urine
Pre eclampsia - proteinuria (>300 mg of protein in a 24-hour urine sample)
Severe pre eclampsia- Proteinuria ≥ 5 g in a 24-hour urine specimen or 3+ or greater on two random urine specimens collected at least four hours apart

Investigations - Management

Fact Explanation
Blood pressure Blood pressure should be checked regularly after delivery and in subsequent pregnancies as women with a history of gestational hypertension or of pre-eclampsia or eclampsia are at increased risk of hypertensive and associated diseases in later life and hypertension during subsequent pragnancies Blood pressure
Blood pressure should be checked regularly after delivery and in subsequent pregnancies as women with a history of gestational hypertension or of pre-eclampsia or eclampsia are at increased risk of hypertensive and associated diseases in later life and hypertension during subsequent pragnancies
Serum creatinine Renal functions can be abnormal due to multi organ failure in pre eclampsia Serum creatinine
Renal functions can be abnormal due to multi organ failure in pre eclampsia
Liver function tests Liver functions can be abnormal due to multi organ failure in pre eclampsia Liver function tests
Liver functions can be abnormal due to multi organ failure in pre eclampsia
Coagulation studies - prothrombin time (PT) and partial thromboplastin time (PTT), fibrinogen levels prothrombin time (PT) and partial thromboplastin time (PTT) is seldom prolonged in pre eclampsia, but it may be prolonged in severe pre eclampsia.
fibrinogen levels may also become low in severe pre eclampsia.
However, abnormal fibrinogen level or prolonged PT / PTT is usually not seen in the absence of thrombocytopenia
Coagulation studies - prothrombin time (PT) and partial thromboplastin time (PTT), fibrinogen levels
prothrombin time (PT) and partial thromboplastin time (PTT) is seldom prolonged in pre eclampsia, but it may be prolonged in severe pre eclampsia.
fibrinogen levels may also become low in severe pre eclampsia.
However, abnormal fibrinogen level or prolonged PT / PTT is usually not seen in the absence of thrombocytopenia
peripheral blood smear HELLP syndrome: hemolysis - evidence of damaged erythrocytes, such as schistocytes and burr cells peripheral blood smear
HELLP syndrome: hemolysis - evidence of damaged erythrocytes, such as schistocytes and burr cells
Serum bilirubin HELLP syndrome: hemolysis - Serum bilirubin ≥ 1.2 mg per dL (21 μmol per L) Serum bilirubin
HELLP syndrome: hemolysis - Serum bilirubin ≥ 1.2 mg per dL (21 μmol per L)
Lactate dehydrogenase (LDH) HELLP syndrome: hemolysis - LDH > 600 U per L (10.02 μkat per L) Lactate dehydrogenase (LDH)
HELLP syndrome: hemolysis - LDH > 600 U per L (10.02 μkat per L)
AST (aspartate aminotransferase) , Alanine transaminase (ALT) Elevated liver enzymes in HELLP syndrome AST (aspartate aminotransferase) , Alanine transaminase (ALT)
Elevated liver enzymes in HELLP syndrome
Full blood count Low platelet count
< 100,000 per mm3 (100 × 109 per L) in HELLP syndrome
Full blood count
Low platelet count
< 100,000 per mm3 (100 × 109 per L) in HELLP syndrome
Trans vaginal ultra sound scan Pregnancy induced hypertension can lead to intra uterine growth restriction of the baby Trans vaginal ultra sound scan
Pregnancy induced hypertension can lead to intra uterine growth restriction of the baby

Management - Supportive

Fact Explanation
Fluid Management Excessive fluid administration can result in pulmonary edema, ascites, and cardiopulmonary overload, whereas too little fluid exacerbates an already constricted intravascular volume and leads to further end-organ ischemia. Urine output should be greater than 30 mL per hour and intravenous fluids limited to 100 mL per hour Fluid Management
Excessive fluid administration can result in pulmonary edema, ascites, and cardiopulmonary overload, whereas too little fluid exacerbates an already constricted intravascular volume and leads to further end-organ ischemia. Urine output should be greater than 30 mL per hour and intravenous fluids limited to 100 mL per hour
Delivery Decisions in Severe Preeclampsia Delivery is the only cure for preeclampsia. Decisions regarding the timing and mode of delivery are based on a combination of maternal and fetal factors. Fetal factors include gestational age, evidence of lung maturity, and signs of fetal compromise on antenatal assessment. Patients with treatment-resistant severe hypertension or other signs of maternal or fetal deterioration should be delivered within 24 hours, irrespective of gestational age or fetal lung maturity. Fetuses older than 34 weeks, or those with documented lung maturity, are also delivered without delay Delivery Decisions in Severe Preeclampsia
Delivery is the only cure for preeclampsia. Decisions regarding the timing and mode of delivery are based on a combination of maternal and fetal factors. Fetal factors include gestational age, evidence of lung maturity, and signs of fetal compromise on antenatal assessment. Patients with treatment-resistant severe hypertension or other signs of maternal or fetal deterioration should be delivered within 24 hours, irrespective of gestational age or fetal lung maturity. Fetuses older than 34 weeks, or those with documented lung maturity, are also delivered without delay
Postpartum Management Women with pre-eclampsia have a 1.53 fold increased risk for postpartum haemorrhage
Most patients with preeclampsia respond promptly to delivery with decreased blood pressure, diuresis, and clinical improvement. Eclampsia may occur postpartum; the greatest risk of postpartum eclampsia is within the first 48 hours. Magnesium sulfate is continued for 12 to 24 hours, or occasionally longer if the clinical situation warrants
Postpartum Management
Women with pre-eclampsia have a 1.53 fold increased risk for postpartum haemorrhage
Most patients with preeclampsia respond promptly to delivery with decreased blood pressure, diuresis, and clinical improvement. Eclampsia may occur postpartum; the greatest risk of postpartum eclampsia is within the first 48 hours. Magnesium sulfate is continued for 12 to 24 hours, or occasionally longer if the clinical situation warrants
Bed rest Women with high blood pressure during pregnancy have often been advised to rest in bed, either at home or in hospital Bed rest
Women with high blood pressure during pregnancy have often been advised to rest in bed, either at home or in hospital

Management - Specific

Fact Explanation
Asprin and other anti platelet agents Pre-eclampsia is associated with deficient intravascular production of prostacyclin, a vasodilator, and excessive production of thromboxane, a platelet-derived vasoconstrictor and stimulant of platelet aggregation. These observations led to the hypotheses that antiplatelet agents, and low dose aspirin in particular, might be effective for prevention of pre-eclampsia.
It is given to at risk patients from 12th week of pregnancy to improve trophoblast invasion and reduce incidence of PIH
Asprin and other anti platelet agents
Pre-eclampsia is associated with deficient intravascular production of prostacyclin, a vasodilator, and excessive production of thromboxane, a platelet-derived vasoconstrictor and stimulant of platelet aggregation. These observations led to the hypotheses that antiplatelet agents, and low dose aspirin in particular, might be effective for prevention of pre-eclampsia.
It is given to at risk patients from 12th week of pregnancy to improve trophoblast invasion and reduce incidence of PIH
Antihypertensive drugs - Methyl dopa Methyldopa (0.5 to 3.0 g/d in 2 divided doses) remains one of the most widely used drugs for the treatment of hypertension in pregnancy. It is a centrally acting α2-adrenergic agonist prodrug, which is metabolized to α-methyl norepinephrine and then replaces norepinephrine in the neurosecretory vesicles of adrenergic nerve terminals. BP control is gradual, over 6 to 8 hours, because of the indirect mechanism of action. safety after first trimester well documented Antihypertensive drugs - Methyl dopa
Methyldopa (0.5 to 3.0 g/d in 2 divided doses) remains one of the most widely used drugs for the treatment of hypertension in pregnancy. It is a centrally acting α2-adrenergic agonist prodrug, which is metabolized to α-methyl norepinephrine and then replaces norepinephrine in the neurosecretory vesicles of adrenergic nerve terminals. BP control is gradual, over 6 to 8 hours, because of the indirect mechanism of action. safety after first trimester well documented
Antihypertensive drugs - Labetalol Labetalol (200 to 1200 mg/d in 2 to 3 divided doses), a nonselective β-blocker with vascular α1-receptor blocking capabilities, has gained wide acceptance in pregnancy. When administered orally to women with chronic hypertension, it seems as safe and effective as methyldopa, although neonatal hypoglycemia with higher doses has been reported.

Parenterally (10 to 20 mg IV, then 20 to 80 mg every 20 to 30 minutes, maximum of 300 mg; for infusion: 1 to 2 mg/min) it is used to treat severe hypertension, because of a lower incidence of maternal hypotension and other adverse effects
Antihypertensive drugs - Labetalol
Labetalol (200 to 1200 mg/d in 2 to 3 divided doses), a nonselective β-blocker with vascular α1-receptor blocking capabilities, has gained wide acceptance in pregnancy. When administered orally to women with chronic hypertension, it seems as safe and effective as methyldopa, although neonatal hypoglycemia with higher doses has been reported.

Parenterally (10 to 20 mg IV, then 20 to 80 mg every 20 to 30 minutes, maximum of 300 mg; for infusion: 1 to 2 mg/min) it is used to treat severe hypertension, because of a lower incidence of maternal hypotension and other adverse effects
Antihypertensive drugs - Nifedipine Calcium channel antagonists have been used to treat chronic hypertension, mild preeclampsia presenting late in gestation, and urgent hypertension associated with preeclampsia.
Orally administered nifedipine (30 to 120 mg/d of a slow-release preparation) and verapamil do not seem to pose teratogenic risks to fetuses exposed in the first trimester.

for Urgent Control of Severe Hypertension in Pregnancy- Tablets recommended only: 10 to 30 mg , repeat in 45 minutes if needed
Antihypertensive drugs - Nifedipine
Calcium channel antagonists have been used to treat chronic hypertension, mild preeclampsia presenting late in gestation, and urgent hypertension associated with preeclampsia.
Orally administered nifedipine (30 to 120 mg/d of a slow-release preparation) and verapamil do not seem to pose teratogenic risks to fetuses exposed in the first trimester.

for Urgent Control of Severe Hypertension in Pregnancy- Tablets recommended only: 10 to 30 mg , repeat in 45 minutes if needed
Antihypertensive drugs - Hydralazine Hydralazine selectively relaxes arteriolar smooth muscle. Its greatest use is in the urgent control of severe hypertension or as a third-line agent for multidrug control of refractory hypertension. It is effective orally (50 to 300 mg/d in 2 to 4 divided doses).

parenteral administration is useful for rapid control of severe hypertension (5 mg, IV or IM, then 5 to 10 mg every 20 to 40 minutes; once BP controlled repeat every 3 hours; for infusion: 0.5 to 10.0 mg/h; if no success with 20 mg IV or 30 mg IM, consider another drug)
Studies regarding the use of intravenous hydralazine in severe hypertension in pregnancy has showed that parenteral labetalol or oral nifedipine were preferable first-line agents, with hydralazine as a suitable second-line agent
Antihypertensive drugs - Hydralazine
Hydralazine selectively relaxes arteriolar smooth muscle. Its greatest use is in the urgent control of severe hypertension or as a third-line agent for multidrug control of refractory hypertension. It is effective orally (50 to 300 mg/d in 2 to 4 divided doses).

parenteral administration is useful for rapid control of severe hypertension (5 mg, IV or IM, then 5 to 10 mg every 20 to 40 minutes; once BP controlled repeat every 3 hours; for infusion: 0.5 to 10.0 mg/h; if no success with 20 mg IV or 30 mg IM, consider another drug)
Studies regarding the use of intravenous hydralazine in severe hypertension in pregnancy has showed that parenteral labetalol or oral nifedipine were preferable first-line agents, with hydralazine as a suitable second-line agent
Antihypertensive drugs - Sodium nitroprusside Sodium nitroprusside is a direct NO donor, which nonselectively relaxes both arteriolar and venular vascular smooth muscle. Administered only by continuous intravenous infusion ( 0.25 to 5.00 μg/kg per minute) for rapid control of severe hypertension.
Possible cyanide toxicity if used for >4 hours, thus agent of last resort
Antihypertensive drugs - Sodium nitroprusside
Sodium nitroprusside is a direct NO donor, which nonselectively relaxes both arteriolar and venular vascular smooth muscle. Administered only by continuous intravenous infusion ( 0.25 to 5.00 μg/kg per minute) for rapid control of severe hypertension.
Possible cyanide toxicity if used for >4 hours, thus agent of last resort
Antihypertensive drugs -Hydrochlorothiazide Hydrochlorothiazide may be continued during pregnancy; the use of low doses (12.5 to 25 mg daily) may minimize untoward metabolic effects, such as impaired glucose tolerance and hypokalemia Antihypertensive drugs -Hydrochlorothiazide
Hydrochlorothiazide may be continued during pregnancy; the use of low doses (12.5 to 25 mg daily) may minimize untoward metabolic effects, such as impaired glucose tolerance and hypokalemia
Preventing the onset of eclampsia Magnesium sulphate should be considered for women with severe pre-eclampsia, and for others about whom there is concern about the risk of eclampsia Preventing the onset of eclampsia
Magnesium sulphate should be considered for women with severe pre-eclampsia, and for others about whom there is concern about the risk of eclampsia
Emergency management of eclampsia Summon senior and obstetric staff
Secure airway and administer high flow oxygen
Place wedge under right hip or nurse in left lateral position
Secure intravenous access and draw blood for full blood count, serum slectrolytes, liver function tests, clotting screen, cross match, and Kleihauer test if abruption suspected.
Fluid: crystalloid - 1–2 ml/kg/h with monitoring of urine output.

Control seizures - Diazepam 5–10 mg slow iv bolus or
Lorazepam 2–4 mg slow iv bolus or
Magnesium sulphate 4–6 g slow iv bolus over 5 minutes then 1–2 g/h iv infusion

Control hypertension -
Give anti hypertensives if mean arterial pressure >125mmHg.
Hydralazine 5 mg slow iv bolus every 20–30 min or Labetalol 10 mg slow iv bolus doubling every 10– 20 min to max 300 mg total or 1–2 mg/min iv infusion.

Monitor vital signs including blood pressure, ECG, respiratory rate, oxygen saturation and fetal heart rate
Catheterise bladder, monitor urine output, and test urine for protein
Emergency management of eclampsia
Summon senior and obstetric staff
Secure airway and administer high flow oxygen
Place wedge under right hip or nurse in left lateral position
Secure intravenous access and draw blood for full blood count, serum slectrolytes, liver function tests, clotting screen, cross match, and Kleihauer test if abruption suspected.
Fluid: crystalloid - 1–2 ml/kg/h with monitoring of urine output.

Control seizures - Diazepam 5–10 mg slow iv bolus or
Lorazepam 2–4 mg slow iv bolus or
Magnesium sulphate 4–6 g slow iv bolus over 5 minutes then 1–2 g/h iv infusion

Control hypertension -
Give anti hypertensives if mean arterial pressure >125mmHg.
Hydralazine 5 mg slow iv bolus every 20–30 min or Labetalol 10 mg slow iv bolus doubling every 10– 20 min to max 300 mg total or 1–2 mg/min iv infusion.

Monitor vital signs including blood pressure, ECG, respiratory rate, oxygen saturation and fetal heart rate
Catheterise bladder, monitor urine output, and test urine for protein
Mean arterial pressure (MAP) MAP can be used as a guide for the management.
Studies indicate that a middle trimester MAP above 90 mm Hg has a sensitivity of 61–71% and a specificity of 62–74% in predicting preeclampsia.

Give intra venous anti hypertensives if mean arterial pressure >125mmHg in management of eclamptic emergency
Mean arterial pressure (MAP)
MAP can be used as a guide for the management.
Studies indicate that a middle trimester MAP above 90 mm Hg has a sensitivity of 61–71% and a specificity of 62–74% in predicting preeclampsia.

Give intra venous anti hypertensives if mean arterial pressure >125mmHg in management of eclamptic emergency

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