headache, blurred vision, convulsions, loss of consciousness or elevated blood pressure advances in...
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Headache, Blurred Vision, Convulsions, Loss of Consciousness or Elevated
Blood Pressure
Advances in Maternal and Neonatal Health
2 Headaches, Elevated Blood Pressure and Convulsions
Session Objectives
Discuss best practices for diagnosing and managing hypertension, pre-eclampsia and eclampsia
Describe strategies for controlling hypertension
Describe strategies for preventing and treating convulsions in pre-eclampsia and eclampsia
3 Headaches, Elevated Blood Pressure and Convulsions
Problem
Pregnant or recently postpartum woman who:
Has elevated blood pressure Complains of headache or blurred vision Is found unconscious or convulsing
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Elevated Blood Pressure
Classifications:
Chronic hypertension Pregnancy-induced hypertension
– Pregnancy-induced hypertension without proteinuria– Mild pre-eclampsia– Severe pre-eclampsia– Eclampsia
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Pre-Eclampsia
Woman over 20 weeks gestation with:
Diastolic blood pressure > 90 mm Hg AND Proteinuria
Predisposes woman to develop eclampsia
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Mild Pre-eclampsia
Two readings of diastolic blood pressure 90-110 mm Hg 4 hours apart after 20 weeks gestation
Proteinuria up to 2+
No other signs/symptoms of severe pre-eclampsia
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Severe Pre-eclampsia
Diastolic blood pressure > 110 mm Hg
Proteinuria > 3+
Other signs and symptoms sometimes present:
Epigastric tenderness Headache Visual changes Hyperreflexia Pulmonary edema Oliguria
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Predicting Pre-eclampsia Using Risk Factors: Study Objective and Design
Objective: To determine if risk factors for pre-eclampsia could be used to predict who develops it
Design: Combined retrospective and prospective analysis
Saudan et al 1998.
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Predicting Pre-eclampsia Using Risk Factors: Study Definitions
Gestational hypertension was defined as the onset of hypertension (systolic blood pressure > 140 mm Hg and/or diastolic blood pressure > 90 mm Hg) after 20 weeks gestation
Pre-eclampsia was diagnosed by standard criteria
Saudan et al 1998.
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Predicting Pre-eclampsia Using Risk Factors: Results
No significant difference in age, parity, gestational age, diastolic blood pressure at presentation or history of diabetes.
Predictor Combined data Significance
Gestation at presentation
0.82 (0.77-0.87) p < 0.0001
Saudan et al 1998.
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Predicting Pre-eclampsia Using Risk Factors: Conclusion
Those women who developed gestational hypertension at an earlier gestational age were more likely to progress to pre-eclampsia.
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Gestational Hypertension and Predicting Pre-eclampsia: Objective and
Design Objective: To determine if there is a “cut off” level of blood
pressure which can be used to predict pre-eclampsia
Design: Cohort study; Blood pressure was recorded in 1000 consecutive pregnancies at each antenatal visit until delivery and at the postpartum visit
Moutquin et al 1985.
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Gestational Hypertension and Predicting Pre-eclampsia: Results
Weeks Gestation(9–28)
Average Sensitivity
Positive Predictive Value
130 mm Hg Systolic BP 46.1 14.3
80 mm Hg Diastolic BP 41.4 21.7
Moutquin et al 1985.
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Gestational Hypertension and Predicting Pre-eclampsia: Conclusions
Approximately 15–25% of women initially diagnosed with gestational hypertension will develop pre-eclampsia
It is difficult to predict who will develop pre-eclampsia
Moutquin et al 1985; Saudan 1998.
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Eclampsia
Convulsions occurring after 20 weeks gestation in a woman without a previously known seizure disorder
A small proportion of women with eclampsia have normal blood pressure
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Strategies for Preventing Eclampsia
Antenatal care and recognition of hypertension
Identification and treatment of pre-eclampsia by skilled attendant
Timely delivery
3.4% of women with severe pre-eclampsia will have a convulsion
Eclampsia is the number one cause of in-hospital maternal death in Nepal
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Predicting Eclampsia Study: Objective and Design
Objective: Investigate potential usefulness of average mean arterial pressure, maximum mean arterial pressure and maximum diastolic pressure in the second trimester to predict the development of pre-eclampsia
Design: Retrospective analysis
Chesley and Sibai 1987.
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Predicting Eclampsia Study: Results
207 nulliparas and 20 multiparas developed eclampsia Average mean arterial pressure in 2nd trimester 90 mm Hg:
22% of nulliparas 30% of multiparas
Maximum mean arterial pressure in 2nd trimester 90 mm Hg: 34% nulliparas 35% multiparas
Maximum diastolic pressure 80 mm Hg: 8.2% nulliparas 30% multiparas
Maximum diastolic pressure 90 mm Hg: 0% nulliparas 5% multiparas
Chesley and Sibai 1987.
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Predicting Eclampsia Study: Conclusions
Cannot use 2nd trimester mean arterial pressure or diastolic pressure to predict eclampsia
Eclampsia is abrupt in onset, without warning signs in about 20% of women
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Initial Assessment and Management of Eclampsia
Shout for help - mobilize personnel
Rapidly evaluate breathing and state of consciousness
Check airway, blood pressure and pulse
Position on left side
Protect from injury but do not restrain
Start IV infusion with large bore needle (16-gauge)
Give oxygen at 4 L/minute
DO NOT LEAVE THE WOMAN UNATTENDED
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Antihypertensive Drugs
Hydralazine
Labetolol
Nifedipine
Principles:
Initiate antihypertensives if diastolic blood pressure > 110 mm Hg
Maintain diastolic blood pressure 90-100 mm Hg to prevent cerebral hemorrhage
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Management During a Convulsion
Give magnesium sulfate IM
Gather emergency equipment (O2, mask, etc)
Position on left side
Protect from injury but do not restrain
DO NOT LEAVE THE WOMAN UNATTENDED
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Anticonvulsive Drugs
Magnesium sulfate
Diazepam
Phenytoin
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Post-convulsion Management
Prevent further convulsions
Control blood pressure
Prepare for delivery (if undelivered)
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Studies to be Reviewed
For severe pre-eclampsia
Magnesium sulfate vs. placebo
For eclampsia
Magnesium sulfate vs. diazepam
Magnesium sulfate vs. phenytoin
Magnesium sulfate and outcome of labor
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Magnesium Sulfate
Use magnesium sulfate in
Women with eclampsia Women with severe pre-eclampsia necessitating delivery
Start magnesium sulfate when decision for delivery is made
Continue therapy until 24 hours after delivery or the last convulsion, whichever occurs last
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Magnesium Sulfate vs. Placebo in Women With Pre-Eclampsia: Objective
and Design Objective: To evaluate the effectiveness of magnesium sulfate
vs. placebo
Design: Double-blinded prospective randomized controlled trial
Tertiary referral obstetrics unit in South Africa
822 women with severe pre-eclampsia necessitating delivery randomly assigned to placebo or magnesium sulfate
Data from 699 women evaluated
Coetzee, Domisse and Anthony 1998.
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Magnesium Sulfate vs. Placebo in Women With Pre-Eclampsia: Results
In women with severe pre-eclampsia, eclampsia occurred 11 times less often in women receiving magnesium sulfate than in women receiving placebo
Coetzee, Domisse and Anthony 1998.
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Magnesium Sulfate vs. Placebo in Women With Pre-Eclampsia: Results
(continued)
Convulsions No Convulsions
Magnesium sulfate 1 (0.3%) 344 (99.7)
No magnesium sulfate 11 (3.2%)* 329 (96.7%)
Coetzee, Domisse and Anthony 1998.
* RR 0.09, 95% CI (0.01–0.69)
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Magnesium Sulfate vs. Placebo in Women With Pre-Eclampsia: Results
(continued)
No significant difference in:
Need for antihypertensive therapy
Number of cesarean sections performed
Number of Live births vs. stillbirths
Average gestational age
Birthweight at delivery
Number of maternal deaths
Coetzee et al 1998.
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Magnesium Sulfate vs. Diazepam for Eclampsia: Study Objective and Design
Objective: To assess effects of magnesium sulfate compared with diazepam when used for the care of women with eclampsia
Design: Randomized controlled trial
Duley and Henderson-Smart 2000a.
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Magnesium Sulfate vs. Diazepam: Recurrence of Convulsions
Convulsions No convulsions Total
Magnesium sulfate
71 547 618
Diazepam 160 458 618
RR 0.45, 95% CI 0.35-0.58
No differences in maternal morbidity and borderline decrease in maternal mortality
Duley and Henderson-Smart 2000a.
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Magnesium Sulfate vs. Phenytoin for Eclampsia: Study Objective and Design
Objective: To assess the effects of magnesium sulfate compared with phenytoin when used for the care of women with eclampsia
Design: Randomized controlled trial
Duley and Henderson-Smart 2000b.
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Magnesium Sulfate vs. Phenytoin: Results
4 trials, 823 women
Magnesium sulfate was associated with a reduction in the recurrence of convulsion when compared to phenytoin (RR 0.30, 95% CI 0.20–0.46)
Magnesium sulfate was also associated with reduced risks of pneumonia (RR 0.66, 95% CI 0.49–0.90) and intensive care unit stay (RR 0.67, 95% CI 0.50–0.89)
Magnesium sulfate reduced the need for babies’ admission to intensive care unit, reduced duration of stay or death in intensive care unit
Duley and Henderson-Smart 2000b.
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Magnesium Sulfate vs. Phenytoin: Recurrence of Convulsions
Convulsions No convulsions Total
Magnesium sulfate
23 400 423
Phenytoin 73 349 422
RR 0.3095% CI 0.20–0.46
Duley and Henderson-Smart 2000b.
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Magnesium Sulfate vs. Phenytoin: Pneumonia
Pneumonia No pneumonia Total
Magnesium sulfate
15 373 388
Phenytoin 34 353 387
RR 0.4495% CI 0.24–0.79
Duley and Henderson-Smart 2000b.
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Magnesium Sulfate vs. Phenytoin: Admission to Neonatal Intensive Care Unit
NICU No NICU Total
Magnesium sulfate
65 323 388
Phenytoin 97 290 387
RR 0.6795% CI 0.50–0.89
Duley and Henderson-Smart 2000b.
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Magnesium Sulfate vs. Phenytoin for Eclampsia: Conclusion
Magnesium sulfate appears to be substantially more effective and safer than phenytoin for treatment of eclampsia
Duley and Henderson-Smart 2000b.
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Magnesium Sulfate and Outcome of Labor: Objective and Design
Objective: To evaluate the outcome of labor in women receiving magnesium sulfate vs. phenytoin.
Design: 2138 women were randomly assigned to magnesium sulfate or phenytoin for prevention of eclampsia
905 nulliparous women met the inclusion criteria:
480 women received phenytoin 425 women received magnesium sulfate
Leveno et al 1998.
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Magnesium Sulfate and Outcome of Labor: Results
Labor Characteristic Magnesium sulfate
(n=425)
Phenytoin
(n=480)
Significance
Therapeutic oxytocin 325 (76%) 350 (73%) Not significant
Admission to delivery (hours, mean SD)
12.87 13.17 Not significant
Prolonged second stage 35 (8) 33 (7) Not significant
Cesarean delivery (total) 78 (18) 85 (18) Not significant
Cesarean delivery (dystocia) 62 (15) 66 (14) Not significant
Leveno et al 1998.
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Magnesium Sulfate and Outcome of Labor: Conclusion
There is no clinical evidence that magnesium sulfate given for intrapartum management of pregnancy-induced hypertension had any effect on the outcome of labor
Leveno et al 1998.
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Magnesium Sulfate and Effect on Labor: Objective and Design
Objective: Evaluate effect of magnesium sulfate on labor
Design:
Study period: March 1995 to June 1996; randomized term mildly pre-eclamptic women to receive magnesium sulfate 6 g bolus then 2 g/hour or saline
Cervical ripening agents/oxytocin at physician’s discretion Women taken off protocol if developed severe pre-
eclampsia
Witlin, Friedman and Sibai 1997.
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Magnesium Sulfate and Effect on Labor: Results
Outcome: Length of labor, duration of latent and active phases, first and second stages
Results:
No difference in duration of oxytocin: magnesium sulfate group 14.1 hours vs. 13.5 hours
Slightly higher dose of oxytocin required in magnesium sulfate group: 13.9 mU/min vs. 11.0 (p=0.036)
No significant postpartum hemorrhage or side effects
Witlin, Friedman and Sibai 1997.
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Magnesium Sulfate and Effect on Labor: Conclusion
Slightly higher doses of oxytocin required in magnesium treated groups, but no difference in labor and no adverse effects
Witlin, Friedman and Sibai 1997.
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Monitoring Hourly
Assess Normal Findings
Level of consciousness Sleepy but arousable
Diastolic blood pressureShould be maintained between 80–100 mm Hg
Respiratory rate 16 breaths/minute or more
Deep tendon reflexes Minimal but present
Fetal heart sounds (if undelivered) Decrease in variability
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Monitoring Hourly
Assess Abnormal Findings Management
Lungs Pulmonary edemaDiscontinue magnesium sulfate
Urine outputFalls below 30 mL/hour or 120 mL/4 hours
Discontinue magnesium sulfate
Uterus (after delivery)
Atonic uterus (postpartum bleeding)
Consider oxytocin for 24 hours after delivery
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Principles of Management
Timing and route of delivery: condition of mother vs. maturity of fetus
Assessment of fetus: evidence of fetal compromise
Control of convulsions
Control of hypertension
Referral due to other organ complications: pulmonary, renal, central nervous system
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Summary
There are many manifestations of increased blood pressure in pregnancy
It is not possible to predict which patients are at risk for severe pre-eclampsia or eclampsia
Vigilant care is needed to make the diagnosis
Once the diagnosis is made, appropriate treatment can reduce morbidity and mortality
Anticonvulsants should be used, with magnesium sulfate being the first line
Antihypertensives should be employed as needed
Close monitoring is needed for side effects
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References
American College of Obstetricians an Gynecologists. 1996. Technical Bulletin Hypertension in Pregnancy. #219.
Chesley LC and BM Sibai. 1987. Blood pressure in mid-trimester and future eclampsia. Am J Obstet Gynecol 157(5): 1258–1561.
Coetzee E, J Dommisse and J Anthony. 1998. A randomised controlled trial of intravenous magnesium sulphate versus placebo in the management of women with severe pre-eclampsia. Br J Obstet Gynaecol 105: 300–303.
Duley L and D Henderson-Smart. 2000a. Magnesium sulphate versus diazepam for eclampsia (Cochrane Review), in The Cochrane Library, Issue 4. Update Software: Oxford.
Duley L and D Henderson-Smart. 2000b. Magnesium sulphate versus phenytoin for eclampsia (Cochrane Review), in The Cochrane Library, Issue 4. Update Software: Oxford.
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References (continued)Leveno KJ et al. 1998. Does magnesium sulfate given for prevention of eclampsia affect the outcome of labor? Am J Obstet Gynecol 178(4): 707–712.
Moutquin J et al. 1985. A prospective study of blood pressure in pregnancy: Prediction of preeclampsia. Am J Obstet Gynecol 151: 191–196.
Saudan P et al. 1998. Does gestational hypertension become pre-eclampsia? Br J Obstet Gynaecol 105: 1177-1184.
Szal SE, MS Croughan-Minihane and SJ Kilpatrick. 1999. Effect of magnesium prophylaxis and preeclampsia on the duration of labor. Am J Obstet Gynecol 180: 1475–1479.
Villar MA and BM Sibai. 1989. Clinical significance of elevated mean arterial blood pressure in second trimester and threshold increase in systolic and diastolic blood pressure during third trimester. Am J Obstet Gynecol 160: 419–423.
Witlin AG, SA Friedman and BM Sibai. 1997. The effect of magnesium sulfate on the duration of labor in women with mild preeclampsia at term: a randomized, double-blind, placebo-controlled trial. Am J Obstet Gynecol 176(3): 623–627.