6-HTN in PREGNANCY 2023............ .pptx

Pregnancy

1. Hypertension In Pregnancy

2. Introduction Hypertension is one of the most common complication during pregnancy Hypertensive disorders during pregnancy occur in women with pre-existing primary or secondary chronic hypertension, and in women who develop new-onset hypertension in the second half of pregnancy . Increased maternal and perinatal morbidity and mortality It is a sign of an underlying pathology that may be preexisting or appears for the first time during pregnancy that is why it is also called as TOXEMIA OF PREGNANCY

3. Hypertensive disorders also carry a risk for the baby. In the most recent UK perinatal mortality report, 1 in 20 (5%) stillbirths in infants without congenital abnormality occurred in women with pre-eclampsia. The contribution of pre-eclampsia to the overall preterm birth rate is substantial; 1 in 250 (0.4%) women in their first pregnancy will give birth before 34 weeks as a consequence of pre-eclampsia and 8–10% of all preterm births result from hypertensive disorders. Half of women with severe pre-eclampsia give birth preterm. Small-for-gestational-age babies (mainly because of fetal growth restriction arising from placental disease) are common, with 20–25% of preterm births and 14–19% of term births in women with pre-eclampsia being less than the tenth centile of birth weight for gestation.

4. definition Blood pressure of 140/90 mmHg or more or an increase of 30 mmHg in systolic and/or 15 mmHg in diastolic blood pressure over the preor early pregnancy level.

5. Incidence 6 % to 8% of all the pregnancies Complicates 10-20% of pregnancies

6. Prevalence Hypertensive disorders during pregnancy occur in women with preexisting primary or secondary chronic hypertension, and in women who develop new-onset hypertension in the second half of pregnancy

7. Risk Factors for Hypertension in Pregnancy Nulliparity Pre-eclampsia in a previous pregnancy Age >40 years or <18 years Family history of pregnancy-induced hypertension Chronic hypertension Chronic renal disease Anti-phospholipid antibody syndrome or inherited thrombophilia

8. Risk Factors for Hypertension in Pregnancy Vascular or connective tissue disease Diabetes mellitus (pre-gestational and gestational) Multi-fetal gestation High body mass index Male Factor

9. Classification of Pregnancy induced hypertension 1 . Chronic hypertension 2. Pre-eclampsia 3. Chronic hypertension with superimposed pre-eclampsia and eclampsia 4. Gestational Hypertension 5. Transient Hypertension 6. HELLP syndrome ( H= Hemolysis EL= Elevated liver enzymes LP= Low platelet count) 7. Eclampsia 8. Superimposed pre-eclampsia or eclampsia 9. Proteinuria

10. 1- Chronic hypertension in pregnancy The presence of hypertension of any cause antedating or before the 20th week of pregnancy beyond the 12 weeks after delivery Women with CH are at low risk and have satisfactory maternal and fetal outcome without any hypertensive therapy, by life-style modification ( consider a healthy diet , aerobic exercise) Risk factors: Age (>40 years) Duration of hypertension (>15 years) Level of BP (>160/110 mm of Hg) Presence of any medical disorder Presence of thrombophilia

11. Effect of Chronic Hypertension on Pregnancy Maternal : superimposed pre-eclampsia/ eclampsia in 15-20% of cases Foetal : Intrauterine growth retardation . Intrauterine fetal death.

12. Prenatal Care for Chronic Hypertensives Electrocardiogram should be obtained in women with longstanding hypertension . Baseline laboratory tests: Urinalysis , urine culture, and serum creatinine, glucose , and electrolytes Tests will rule out renal disease, and identify comorbidities such as diabetes mellitus. Women with proteinuria on a urine dipstick should have a quantitative test for urine protein

13. Management of chronic hypertension in pregnancy 1- Non-pharmacological : Life style modifications : -Encourage women with chronic hypertension to keep their dietary sodium intake low, either by reducing or substituting sodium salt, because this can reduce blood pressure. - Aerobic exercise .

14. Medical treatment of Chronic hypertension Women with mild chronic hypertension often do not require antihypertensive therapy during most of pregnancy. Pharmacologic treatment of mild hypertension does not reduce the likelihood of developing preeclampsia later in gestation and increases the likelihood of intrauterine growth restriction. If maternal blood pressure exceeds 160/100 mm Hg, however, drug treatment is recommended. Antihypertensive medication may be withheld or discontinued, with subsequent close observation of blood pressure. Because blood pressure drops during normal pregnancy.

15. 2- Pre-eclampsia Definition It is a multisystem disorder of unknown etiology characterized by development of hypertension to the extent of 140/90 mm of Hg or more with proteinuria after the 20th week in a previously normotensive and non- proteinuric women

16. Incidence: • varies widely from 5% to 15% The incidence in primi -gravidae is about 10% and in multi-gravidae is 5% More common in women with chronic hypertension, with an incidence of approximately 25%

17. Pre-disposing factors Primigravidae more than multi-gravidae. Pre-existing hypertension. Previous pre-eclampsia. Family history of pre-eclampsia. Hyperplacentosis i.e. excessive chorionic tissue as in hydatidiform mole , multiple pregnancy, uncontrolled diabetes mellitus. Obesity . New paternity Thrombophilias

18. Pathophysiology The uteroplacental bed Immunological factor Genetic factor Renin- angiotensin system Prostaglandins Neutrophils

19. Clinical features: Symptoms : Mild: slight swelling over the ankle Gradually swelling may be extend to the face, abdominal wall, vulva ,even the whole body . Alarming : Headache Disturbed sleep Diminished urinary output Epigastric pain Eye symptoms- blurring, scotomata , dimness of vision or at times complete blindness. Vision usually regained within 4-6 weeks following d elivery.

20. Signs: Abnormal weight gain Rise of blood pressure Edema There is no manifestation of chronic cardiovascular or renal pathology Pulmonary edema placental insufficiency such as scanty liquor or growth retardation of the fetus

21. Diagnostic criteria: Pre-eclampsia is diagnosed when a pregnant woman develops : Blood pressure ≥ 140 mm Hg systolic or ≥ 90 mm Hg diastolic on two separate readings taken at least four to six hours apart after 20 weeks gestation in an individual with previously normal blood pressure. In a woman with essential hypertension beginning before 20 weeks gestational age, the diagnostic criteria are: an increase in systolic blood pressure (SBP) of ≥30mmHg or an increase in diastolic blood pressure (DBP) of ≥15mmHg. Proteinuria ≥ 0.3 grams (300 mg) or more of protein in a 24-hour urine sample or a SPOT urinary protein to creatinine ratio ≥ 0.3 or a urine dipstick reading of 1+ or greater.

22. Investigations: Urine : 24 hours urine collection for protein measurement is done. Urine become solid on boiling (10-15 g/L) A few hyaline cast, epithelial cells or few red cells.  Ophthalmoscopic examinations: In severe cases- retinal edema, constriction of arterioles, hemorrhage

23. Investigations: Blood values: -Serum uric acid level > 4.5 mg/dl indicates presences of pre-eclampsia -Blood urea level remains normal -Abnormal coagulation profile -Raised hepatic enzyme levels

24. Complications Maternal : During pregnancy: Eclampsia (2%) Accidental hemorrhage Oliguria and anuria Dimness of vision even blindness Pre-term labour HELLP syndrome Cerebral hemorrhage Acute respiratoy distress syndrome (ARDS)

25. complications During labour : Eclampsia Post partum hemorrhage (PPH ) Puerperium : Eclampsia

26. Fetal: Intrauterine death (IUD) Intrauterine growth retardation (IUGR) Asphyxia prematurity

27. Prediction No screening test is really helpful Various screening methods are: Diastolic notch at 24weeks by Doppler ultrasonography Absence or reversal of end diastolic flow Average mean arterial pressure ≥ 90 mmHg in second trimester Infusion test: angiotensin infusion required to raise the blood pressure >20 mm Hg from baseline Roll over test: Rise in blood pressure >20 mmHg from baseline on turning supine at 28-32 weeks gestation is positive

28. Pre-eclampsia management General measures: Maternal Blood pressure twice daily Urine volume and proteinuria daily Oedema daily Body weight twice weekly Fundus oculi once weekly • Blood picture including platelet count , liver and renal functions particularly serum uric acid on admission

29. Fetal: Daily foetal movement count s erial sonography Non-stress and stress test if needed

30. Medical treatment Antihypertensives : Decrease the maternal cerebral and cardiovascular complications but do not affect the foetal outcome 1- Alpha-methyl- dopa : reduces the central sympathetic drive Dose : 250-500 mg every 6-8 hours up to a maximum dose of 4 gm/day. Its effect appears after 48 hours A loading single dose of 2 gm may act within 1-2 hours Side effects: headache Postural hypotension and nightmares

31. Medical treatment (cont.) 2- Hydralazine : It is a vasodilator, increases renal and uteroplacental blood flow Dose: 20 mg slowly IV initially followed by 5mg every 20 min. until diastolic blood pressure is 100-110 mmHg. This regimen is used for severe and acute hypertension. Oral hydralazine can be used in the chronic situation as a second line treatment in a dose of 25-75 mg/ 6 hours Side effects: tachycardia, headache, flushing, nausea and vomiting 3- Calcium channel blockers ( Nifedipine ): It is a vasodilator acting by blocking the Ca influx into smooth muscle cells It can be given sublingually (acts within 10 minutes) or orally ( acts within 30 minutes) in a dose of 10-20 mg 2-3 times daily The higher the starting blood pressure the greater is the hypotensive effect . Side effects: headache and flushing

32. Prophylactic Proper antenatal care: To detect the high risk patients who may develop PIH through the screening tests Early detection of cases who have already developed PIH and examine them more frequently l ow dose aspirin: It inhibits thromboxane production from the platelets and the AII binding sites on platelets A low dose (60 mg daily) selectively inhibits thromboxane due to higher concentration of such a low dose in the portal circulation than systemic affecting the platelets when they pass through the portal circulation. The Prostacyclin production from the systemic vessels will not be affected

33. Curative Delivery of the foetus and placenta is the only real treatment of preeclampsia. As the conditions are not always suitable for this, the treatment aims to prevent or minimize the maternal and foetal complications till reasonable maturation of the foetus .

34. Obstetric measures Timing of delivery Method of delivery Intrapartum care Postpartum care

35. Obstetric measures Timing of delivery: Severe pre-eclampsia is usually treated conservatively till the 36th week to ensure reasonable maturation of the foetus . Indications of termination before 36th week include: 1. Aggravation of pre- eclamptic features 2. Hypertension persists 3. Acute fulminating pre-eclampsia 4. Tendency of pregnancy to overrun the expected date

36. Method of delivery Vaginal delivery may be commenced in vertex presentation by: Amniotomy + oxytocin if the cervix is favorable Prostaglandin vaginal tablet (PGE2) if the cervix is not favorable Caesarean section is indicated in: Fetal distress Late deceleration occurs with oxytocin challenge test Failure of induction of labour Other indications as contracted pelvis, and malpresentations

37. Intrapartum care Close monitoring of the foetus is indicated Proper analgesia to the mother Anti- hypertensives may be given if needed 2nd stage of labour may be shortened by forceps

38. Postpartum care Methergin ( Ergometrine ) is better avoided as it may increase the blood pressure Continues observation of the mother for 48 hours Anti- hypertensive drugs are continued in a decreasing dose for 48 hours

39. Prevention of preeclampsia Identification of high-risk women Close clinical and laboratory monitoring aimed at its early recognition Institution of intensive monitoring or delivery when indicated.

40. Note Imminent eclampsia: It is a state in which the patient is about to develop eclampsia. Usually there are: Blood pressure much higher than 160 /110 mmHg Heavy proteinuria (+++or ++++) Hyperreflexia Severe continuous headache Blurring of vision Epigastric pain Fulminating pre-eclampsia: a rapidly deteriorating pre-eclampsia to be imminent eclampsia

41. Chronic hypertension with superimposed pre-eclampsia or eclampsia The common cause of chronic hypertension: - Essential hypertension - Chronic renal disease - Coarctation of aorta - Endocrine disorders (DM, pheochromocytoma , thyrotoxicosis ) Connective tissue disease (SLE ) Criteria for diagnosis of superimposed pre-eclampsia: - New onset of proteinuria >0.5 g/24 hours specimen - Aggravation of hypertension - Development of HELLP syndrome - Development of headache scotoma , epigastric pain

42. 3- Gestational hypertension A sustained rise of blood pressure to 140/90 mm of Hg or more on at least two occasions 4 or more hours apart beyond the 20th week of pregnancy.

43. It should fulfill the following criteria: - Absence of any evidences for the underlying cause of hypertension - Generally unassociated with other evidences of pre-eclampsia (or proteinuria) - Majority of cases are more than or equal to 37 weeks of pregnancy - Generally not associated with hemo -concentration or thrombocytopenia , raised serum uric acid level or hepatic dysfunction - The blood pressure should come down to normal within 12 weeks following delivery.

44. Pathophysiology Cardiovascular effects Elevated BP Increased cardiac output Hematologic effects Third spacing of fluid due to increased blood pressure and decreased plasma oncotic pressure Renal effects Atherosclerotic like changes in renal vessels (glomerular endotheliosis ) ---> decreased glomerular filtration rate and proteinuria Uric acid filtration is decreased

45. Neurologic effects Hyper- reflexia /hypersensitivity (does not correlate with severity of disease) In severe cases, grand mal seizures Pulmonary effects Pulmonary edema may occur due to decreased colloid oncotic pressure Fetal effects (severe gestational HTN) Vasospasm  Decreased intermittent placental perfusion  IUGR, oligo-hydramnios , low birth weight

46. Uterine vascular changes: Trophoblastic-mediated vascular changes  decreased musculature in spiral arterioles  development of low resistance , low pressure, high-flow system Inadequate maternal vascular response Endothelial damage is also noted within the vessels Hemostatic changes Increased PLT activation with increased endothelial fibro- nectin and decreased anti-thrombin III and alpha-2-antiplasmin  further endothelial damage is thought to promote further vasospasm

47. Changes in prostanoids During pregnancy, both PGI2 (vasodilation and decreased PLT aggregation ) and ( vasoconstriction and PLT aggregation) are increased with balance favored to PGI 2 Changes in endothelium-derived factors Decrease in Nitric oxide  promoting vasoconstriction

48. 4- Transient Hypertension • Retrospective diagnosis • BP normal by 12 weeks postpartum • May recur in subsequent pregnancies • Predictive of future primary hypertension

49. 5- HELLP Syndrome He = hemolysis EL =elevated liver enzymes LP = low platelets 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

50. Management of HELLP syndrome: Immediate hospitalisation Stabilise mother Antihypertensive Anti-seizure prophylaxis Correct coagulation abnormalities Assess foetal condition- FHR, Doppler ultrasound, biophysical profile

51. 6 -Eclampsia

52. Definition Pre-eclampsia when complicated with grandmal seizures (generalized tonic clonic seizures) and/or coma is called eclampsia

53. Incidence and prevalence 0.1- 5.5 per 10,000 pregnancies Decreasing incidence with time Antepartum(50 %): mostly in third trimester Intrapartum (30 %) Postpartum(20 %): usually within 48hours, fits beyond 7days generally rules out eclampsia

54. Risk factors: Maternal age less than 20 years Multigravida Molar pregnancy Triploidy Pre-existing hypertension or renal disease Previous severe Preeclampsia or Eclampsia Nonimmune hydrops fetalis Systemic Lupus Erythematosus

55. Clinical Features Eclamptic convulsions are epileptiform and consist of four stages • Premonitory stage: twitching of muscles of face, tongue, limbs and eye. Eyeballs rolled or turned to one side • Tonic stage: limbs flexed, hands clenched • Clonic stage: 1-4 min, frothing, tongue bite, stertorous breathing • Stage of coma: variable period

56. Pathogenesis: Loss of normal cerebral auto regulatory mechanisms cerebral hyperperfusion leading to Edema & ↓cerebral blood flow.

57. Diagnosis: Lab Investigations: • Complete Blood Count • Platelet count • LFT • RFT • Urine analysis • Serum electrolytes • Peripheral blood smear • Prothrombin time • Type and screen antibody if present • Angiotensin II test: a dose of 8mk/kg/body weight to increase Diastolic Blood pressure by 20 mm of Hg is taken as positive

58. Differential diagnosis Epilepsy Hysteria Encephalitis Meningitis Poisoning Cerebral malaria Intracranial tumor

59. Management goals Control Hypertension Improve intravascular volume Prevent convulsions Prevent complications Deliver viable fetus

60. Control Hypertension: Most commonly, for acute control: Hydralazine Labetalol Nifedipine may be used, but unexpected hypotension may occur when given with magnesium sulphate (MgSO4) For refractory hypertension: nitroglycerin or nitroprussied maybe used Nitroprusside dose and duration should be limited to avoid fetal cyanide toxicity Usually require invasive arterial pressure monitoring Angiotensin-converting enzyme (ACE) inhibitors contraindicated due to severe adverse fetal effect

61. Improve intravascular volume: Main aim is to increase CVP & PCWP range 4-6 cm H2O & 5-10 mm HG and to increase urine output to 1 ml/kg/hr. There is a controversy between colloid and crytalloid as both complicates the condition causing low colloid oncotic pressure and leaky capillary predisposing them to risk of noncarcinogenic pulmonary oedema Fluid recommendation: crystalloids to be administered at the rate of 1-2 ml/kg/hr. and alternating according to CVP,PCWP and Urine Output.

62. Seizure Prophylaxis & Treatment: Magnesium sulphate therapy: Magnesium sulfate has many effects ; its mechanism in seizure control is not clear. It is an NMDA (N-methyl-D-aspartate) antagonist vasodilator

63. Potential adverse effectsof MgSO4 : Toxicity from overdose (respiratory, cardiac) Bleeding Hypotension with haemorrhage Uterine contractility Notes: Renally excreted Preeclamptics prone to renal failure Magnesium levels must be monitored frequently either clinically (patellar reflexes) or by checking serum levels for 6-8 hours

64. Treatment of magnesium toxicity: -Stop MgSO4 - IV 1 g 10% calcium gluconate slow Administer Oxygen - Secure airway - Ventilation

65. Anaesthetic Implication: MgSo4 potentiate and prolongs both actions of depolarizing and non-depolarizing Muscle relaxants. Intubating dose of succinylcholine should not be decreased as onset and duration of action of single dose does not alter in preeclamptic patients . NDMR when used neuromuscular monitoring with peripheral nerve stimulation and dose titration should be done accordingly.

66. Various Regime of Magnesium Therapy : • Pritchard Regime: - Loading dose: 4g (20 ml of 20%) MgSo4 IV over 4 min. immediately followed by 10g (20 ml of 50%) IM i.e. 5 gm in each buttocks - If convulsion persists after 15 min 2 g IV over 2 min Maintenance dose: 5g IM every 4 hours alternate side • Zuspan or Sibai regime: dose : 5g IM every 4 hours alternate side - Loading dose: 6 g IV over 20 min - Maintenance dose: 2-3 g/hr. IV every 6 hr

67. Treatment of Eclampsia: Seizures are usually short-lived. • If necessary, small doses of barbiturate or benzodiazepine (STP , 50 mg, or midazolam, 1-2 mg) and supplemental oxygen by mask • If seizure persists or patient is not breathing, rapid sequence induction with cricoid pressure and intubation should be performed • Patient may be extubated once she is completely awake, recovered from neuromuscular blockade, and magnesium sulfate has been administered

68. Superimposed pre-eclampsia or eclampsia Occurrence of new onset of proteinuria in women with chronic Hypertension Risk factors: Renal insufficiency History of hypertension for 4 years or more Hypertension in previous pregnancy

69. Proteinuria (albuminuria) It is urinary protein greater than 0.3gm/L in 24 hours collection or greater than 1gm/L in two random samples obtained at least 6 hours apart It indicates glomerular damage and almost always occurs after hypertension Proteinuria is usually in the range of 1-3 gm daily, of which 50-60% is albumin but in severe cases it may exceed 15gm

70. Treating hypertension during lactation Hypertensive mothers can usually breast-feed safely. Antihypertensive drugs are excreted into human breast milk. Therefore , in mothers with stage 1 hypertension who wish to breast-feed for a few months, it might be prudent to withhold antihypertensive medication, with close monitoring of BP, and reinstitute antihypertensive therapy following discontinuation of nursing . No short-term adverse effects have been reported from exposure to methyldopa or hydralazine. Propanolol and labetalol are preferred if a beta-blocker is indicated. ACEIs and ARBs should be avoided, based on reports of adverse fetal and neonatal renal effects. Diuretics may reduce milk volume and thereby suppress lactation. Breast-fed infants of mothers taking antihypertensive agents should be closely monitored for potential adverse effects.

71. Thank you