headache, blurred vision, convulsions, loss of consciousness or elevated blood pressure advances in...

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


Problem

Pregnant or recently postpartum woman who:

Has elevated blood pressure Complains of headache or blurred vision Is found unconscious or convulsing


Elevated Blood Pressure

Classifications:

Chronic hypertension Pregnancy-induced hypertension

– Pregnancy-induced hypertension without proteinuria– Mild pre-eclampsia– Severe pre-eclampsia– Eclampsia


Pre-Eclampsia

Woman over 20 weeks gestation with:

Diastolic blood pressure > 90 mm Hg AND Proteinuria

Predisposes woman to develop eclampsia


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


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


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.


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.


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.


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.


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.


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.


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.


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


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


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.


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.


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


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


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


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


Anticonvulsive Drugs

Magnesium sulfate

Diazepam

Phenytoin


Post-convulsion Management

Prevent further convulsions

Control blood pressure

Prepare for delivery (if undelivered)


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


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


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.


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




(continued)

Convulsions No Convulsions

Magnesium sulfate 1 (0.3%) 344 (99.7)

No magnesium sulfate 11 (3.2%)* 329 (96.7%)


* RR 0.09, 95% CI (0.01–0.69)



(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.


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.


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.


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.


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



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



Magnesium Sulfate vs. Phenytoin: Pneumonia

Pneumonia No pneumonia Total

Magnesium sulfate

15 373 388


RR 0.4495% CI 0.24–0.79



Magnesium Sulfate vs. Phenytoin: Admission to Neonatal Intensive Care Unit

NICU No NICU Total

Magnesium sulfate

65 323 388


RR 0.6795% CI 0.50–0.89



Magnesium Sulfate vs. Phenytoin for Eclampsia: Conclusion

Magnesium sulfate appears to be substantially more effective and safer than phenytoin for treatment of eclampsia



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.


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.


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.


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.


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



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



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


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


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


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


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.


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.

headache, blurred vision, convulsions, loss of consciousness or elevated blood pressure advances in...

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