CHAPTERS CONTRIBUTED

Management of Hypertensive Crisis in Labour

By
Dr. Pankaj Desai MD, FICOG, FICMCH
Chief of Unit in Obgyn (VRS)
Medical College and S.S. G. Hospital
Baroda, INDIA
Call: 91-265-2437793/ 2432519
Facsimile: 91-265-2435345
Email: drpankajdesai@gmail.com

Dr. Purvi Patel MD (O. & G.)
Assistant Professor
Dept. Of Obgyn
Medical College and S.S. G. Hospital
Baroda, INDIA
Call: 91-265-2664075
Email: patel_purvi_k@hotmail.com

Pregnant women with severe hypertension (systolic over 160 mmHg, diastolic 110 mmHg or more) are a vulnerable group for serious maternal and fetal/neonatal complications, hence prompt and adequate control of hypertensive crisis is vital in the obstetric population.

The mainstay of the management of hypertensive crisis remains antihypertensive therapy. The aim of antihypertensive therapy is to lower blood pressure quickly but safely, to avoid complications and to prevent end-organ damage to the mother and the fetus. The target BP is systolic between 140-160 and diastolic between 90-110 mm Hg. The most recent Cochrane systematic review1 considered the effectiveness of anti-hypertensives for treatment of severe hypertension during pregnancy and concluded that there is no evidence that one antihypertensive agent is preferable to the others for improving outcome for women with very high blood pressure during pregnancy, and their babies. They concluded that until better evidence is available, the choice of antihypertensive should depend on what is known about adverse drug effects and how familiar the clinician is with a particular drug. Parenteral Hydralazine, parenteral Labetalol and oral Nifedipine are currently accepted for management of severe hypertension in pregnancy. The drug administration protocols2,3,4 are as given in box 1-3. If IV access is not yet obtained and treatment for acute-onset, severe hypertension is urgently needed, a 200-mg dose of labetalol can be administered orally and repeated in 30 minutes if an appropriate improvement is not observed.

Magnesium sulfate is not recommended as an antihypertensive agent, but magnesium sulfate remains the drug of choice for seizure prophylaxis in severe preeclampsia.

Once the hypertensive emergency is treated, a complete and detailed evaluation of maternal and fetal well-being is needed with consideration of the need for subsequent pharmacotherapy and the appropriate timing of delivery. Biochemical investigations to rule out maternal complications of preeclampsia (complete blood count, liver function tests, coagulation profile, renal function tests) and intrapartum cardiotocography for fetal surveillance are to be performed.
The general consensus would be induction of labour especially if the pregnancy has crossed 34 weeks of gestation. The severity of disease and maternal/ fetal condition may still be the deciding factor for practitioners at this stage.
Monitoring/observations

Initial monitoring/observations:

• Record blood pressure readings EVERY 5 MINUTES on the electronic partogram during administration of IV /loading dose.
• Continue observation of BP every 15 minutes until the BP is maintained at 140-160/ 90-100mmHg for two hours.
• The frequency of blood pressure monitoring can then be reduced to every 30 minutes for the duration of the infusion.

Other monitoring/observations:

• Half hourly blood pressure, pulse, respiratory rate while infusion in progress.
• 1 hourly urine output measurement.
• 4 hourly testing of urinary protein (full ward test).
• Continuous electronic fetal monitoring
• Fluid balance chart.
 

Box 1
Order Set for Severe Intrapartum Hypertension Initial First-Line
Management with Labetalol

• Institute fetal surveillance if undelivered and fetus is viable.
• If severe BP elevations persist for 15 minutes or more, administer labetalol (20 mg intravenously [IV] over 2 minutes).
• Repeat BP measurement in 10 minutes and record results.
• If either BP threshold is still exceeded, administer labetalol (40 mg IV over 2 minutes). If BP is below threshold, continue to monitor BP closely.
• Repeat BP measurement in 10 minutes and record results.
• If either BP threshold is still exceeded, administer labetalol (80 mg IV over 2 minutes). If BP is below threshold, continue to monitor BP closely.
• Repeat BP measurement in 10 minutes and record results.
• If either BP threshold is still exceeded, administer hydralazine (10 mg IV over 2 minutes). If BP is below threshold, continue to monitor BP closely.
• Repeat BP measurement in 20 minutes and record results.
• If either BP threshold is still exceeded, obtain emergency consultation from maternal–fetal medicine, internal medicine, anesthesia, or critical care subspecialists.
• Give additional antihypertensive medication per specific order.
• Once the aforementioned BP thresholds are achieved, repeat BP measurement every 10 minutes for 1 hour, then every 15 minutes for 1 hour, then every 30 minutes for 1 hour, and then every hour for 4 hours.
• Institute additional BP timing per specific order.

 

Box 2
Order Set for Severe Intrapartum Hypertension Initial First-
Line Management with Hydralazine

• Institute fetal surveillance if undelivered and fetus is viable.
• If severe BP elevations persist for 15 minutes or more, administer hydralazine (5 mg or 10 mg intravenously [IV] over 2 minutes).
• Repeat BP measurement in 20 minutes and record results.
• If either BP threshold is still exceeded, administer hydralazine (10 mg IV over 2 minutes). If BP is below threshold, continue to monitor BP closely.
• Repeat BP measurement in 20 minutes and record results.
• If either BP threshold is still exceeded, administer labetalol (20 mg IV over 2 minutes). If BP is below threshold, continue to monitor BP closely.
• Repeat BP measurement in 10 minutes and record results.
• If either BP threshold is still exceeded, administer labetalol (40 mg IV over 2 minutes) and obtain emergency consultation from maternal–fetal medicine, internal medicine, anesthesia, or critical care subspecialists.
• Give additional antihypertensive medication per specific order.
• Once the aforementioned BP thresholds are achieved, repeat BP measurement every 10 minutes for 1 hour, then every 15 minutes for 1 hour, then every 30 minutes for 1 hour, and then every hour for 4 hours.

 

Box 3
Order Set for Severe Intrapartum Hypertension Initial First-
Line Management with Oral Nifedipine

• Institute fetal surveillance if undelivered and fetus is viable.
• If severe BP elevations persist for 15 minutes or more, administer nifedipine (10 mg orally).
• Repeat BP measurement in 20 minutes and record results.
• If either BP threshold is still exceeded, administer nifedipine capsules (20 mg orally). If BP is below threshold, continue to monitor BP closely.
• Repeat BP measurement in 20 minutes and record results.
• If either BP threshold is still exceeded, administer nifedipine capsule (20 mg orally). If BP is below threshold, continue to monitor BP closely.
• Repeat BP measurement in 20 minutes and record results.
• If either BP threshold is still exceeded, administer labetalol (40 mg intravenously over 2 minutes) and obtain emergency consultation from maternal–fetal medicine, internal medicine, anesthesia, or critical care subspecialists.
• Give additional antihypertensive medication per specific order.
• Once the aforementioned BP thresholds are achieved, repeat BP measurement every 10 minutes for 1 hour, then every 15 minutes for 1 hour, then every 30 minutes for 1 hour, and then every hour for 4 hours.
• Institute additional BP timing per specific order


References:
1. Duley L, Henderson-Smart DJ, Meher S (2013) Drugs for treatment of very high blood pressure during pregnancy. Cochrane Database Syst Rev.

2. The seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. NIH Publication No. 04-5230. Bethesda (MD): NHLBI; 2004. Available at: http://www.nhlbi.nih.gov/files/docs/guidelines/jnc7full.pdf. Retrieved October 14, 2014.

3. Emergent therapy for acute-onset, severe hypertension during pregnancy and the postpartum period. Committee Opinion No. 623. American College of Obstetricians and Gynecologists. Obstet Gynecol 2015;125:521–5.

4. Brad Holbrrok, Pranita Nirgudkar, Ellen Mozurkewich. Efficacy of hydralazine, labetalol, and nifedipine for the acute reduction of severe hypertension in pregnancy: a systematic review. AJOG 2015. 212(1), s286-s287

 
     

 
     

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