Hypertension.ppt obstetric lecture pre clamsia

Hypertention obstetric lectures

1. Hypertension in Pregnancy

2. OBJECTIVES
List criteria for the diagnosis of
preeclampsia
List criteria for the diagnosis of severe
preeclampsia/HELLP syndrome
Discuss current management
considerations

3. Hypertension
Sustained BP elevation of 140/90 or
greater
Proper cuff size
Measurement taken while seated
Use 5
th
Korotkoff sound

4. Forms of HTN in Pregnancy
Gestational Hypertension
Formerly called Pregnancy-Induced
Hypertension
No proteinuria

5. Forms of HTN in Pregnancy
Gestational Hypertension
Preeclampsia
Hypertension with proteinuria
May have other evidence of end-organ disease
Edema
Visual changes
Headache
Epigastric pain
Laboratory changes

6. 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

7. Patient Categories
E lev ate d BP a bo ve
first trim ester
le ve ls
5 5 -7 5%
G estationa l h ype rte nsion
N o p ro teinu ria
P ree clam psia
H ype rte nsion
P ro te in uria
5 -8% of p ro g na ncies
P a tie nt with H ype rte nsion
25%

8. Forms of HTN in Pregnancy
Gestational Hypertension
Preeclampsia
Chronic Hypertension
As a group these occur in 12 to 22% of
pregnant patients and are directly
responsible for approximately 18% of
maternal mortality nationally.

9. Chronic Hypertension
Pre-existing hypertension
Hypertension before 20 weeks in the
absence of gestation
If hypertension persists beyond 6 weeks
postpartum

10. Preeclampsia
Hypertension after 20
weeks of gestation
Proteinuria- 300mg
Edema

11. Preeclampsia
Hypertension after 20
weeks of gestation
Proteinuria- 300mg
Edema
BP > 160 systolic or >110
diastolic
5grams of protein in 24 hour
urine
Oliguria
Cerebral of visual distrubances
Pulmonary edema or cyanosis
Epigastric or RUQ pain
Impaired liver function
Thrombocytopenia
IUGR

12. Risk Factors
FACTOR RISK RATIO
Nulliparity 3:1
Age > 40 3:1
African American 1.5:1
Chronic hypertension10:1
Renal disease 20:1
Antiphospholipid
syndrome
10:1

13. Risk Factors
FACTOR RISK RATIO
Family history of PIH5:1
Diabetes mellitus 2:1
Twin gestation 4:1

14. Prevention
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.

15. Cardiovascular Effects
Hypertension
Increased cardiac output
Increased systemic vascular resistance
Hypovolemia

16. Neurologic Effects
Seizures-eclampsia
Headache
Cerebral edema
Hyper-reflexia

17. Pulmonary Effects
Capillary leak
Reduced colloid osmotic pressure
Pulmonary edema

18. Hematologic Effects
Volume contraction
Elevated hematocrit
Low platelets
Anemia due to hemolysis

19. Renal Effects
Decreased glomerular filtration rate
Increased BUN/creatinine
Proteinuria
Oliguria
Acute tubular necrosis

20. Fetal Effects
Increased perinatal morbidity
Placental abruption
Fetal growth restriction
Oligohydramnios
Fetal distress

21. Severe Preeclampsia
BP > 160-180
systolic or 110
diastolic
Proteinuria > 5 g per
day
Pulmonary edema
Oliguria
Elevated liver
enzymes
Low platelets
Growth restriction
Decreased AFV
Headache
Epigastric pain

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

23. 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

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

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

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

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

28. Criteria for Treatment
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

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

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

31. Acute Medical Therapy
Hydralazine
Labetalol
Nifedipine
Nitroprusside
Diazoxide
Clonidine

32. Hydralazine
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

33. Labetalol
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

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

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

36. 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

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

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

39. Toxicity
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

40. Treatment of Eclampsia
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

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

42. Alternate Anticonvulsants
Diazepam 5-10 mg IV
Sodium Amytal 100 mg IV
Pentobarbital 125 mg IV
Dilantin 500-1000 mg IV infusion

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

44. Other Complications
Pulmonary edema
Oliguria
Persistent hypertension
DIC

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

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

47. 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 oliguria almost never requires a
PA cath

48. 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

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

50. 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

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

52. 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

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

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