Committee Opinion
Number 623, February 2015
(Reaffirmed 2016. Replaces Committee Opinion Number 514, December 2011)


Committee on Obstetric Practice
This document reflects emerging clinical and scientific advances as of the date issued and is subject to change. The information should not be construed as dictating an exclusive course of treatment or procedure to be followed.


PDF Format

Emergent Therapy for Acute-Onset, Severe Hypertension During Pregnancy and the Postpartum Period

ABSTRACT: Acute-onset, severe systolic hypertension; severe diastolic hypertension; or both can occur in pregnant women or women in the postpartum period. Introducing standardized, evidence-based clinical guidelines for the management of patients with preeclampsia and eclampsia has been demonstrated to reduce the incidence of adverse maternal outcomes. Individuals and institutions should have mechanisms in place to initiate the prompt administration of medication when a patient presents with a hypertensive emergency. Once the hypertensive emergency is treated, a complete and detailed evaluation of maternal and fetal well-being is needed with consideration of, among many issues, the need for subsequent pharmacotherapy and the appropriate timing of delivery.


Box 1. Order Set for Severe Intrapartum or
Postpartum Hypertension Initial First-Line
Management With Labetalol*

  • Notify physician if systolic blood pressure (BP) measurement is greater than or equal to 160 mm Hg or if diastolic BP measurement is greater than or equal to 110 mm Hg.
  • 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.

*Please note there may be adverse effects and contraindications.

Data from National Heart, Lung, and Blood Institute. 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.

Risk reduction and successful, safe clinical outcomes for women with preeclampsia or eclampsia require appropriate and prompt avoidance and management of severe systolic and severe diastolic hypertension (1). Integrating standardized order sets into everyday safe practice in the United States is a challenge. Increasing evidence indicates that standardization of care improves patient outcomes (2). Introducing standardized, evidence-based clinical guidelines for the management of patients with preeclampsia and eclampsia has been demonstrated to reduce the incidence of adverse maternal outcomes (3, 4).With the advent of pregnancy hypertension guidelines in the United Kingdom, care of maternity patients with preeclampsia or eclampsia improved significantly and maternal mortality rates decreased because of a reduction in cerebral and respiratory complications (5, 6). Individuals and institutions should have mechanisms in place to initiate the prompt administration of medication when a patient presents with a hypertensive emergency (7). The use of checklists may be a useful tool to facilitate this process. This document revises Committee Opinion Number 514, Emergent Therapy for Acute-Onset, Severe Hypertension With Preeclampsia or Eclampsia, primarily to include nifedipine as a first-line therapy option for acute-onset, severe hypertension during pregnancy and the postpartum period.

Acute-onset, severe systolic (greater than or equal to 160 mm Hg) hypertension; severe diastolic (greater than or equal to 110 mm Hg) hypertension; or both can occur in pregnant women or women in the postpartum period. This can occur in the second half of gestation in women not known to have chronic hypertension who develop sudden, severe hypertension (ie, with preeclampsia, gestational hypertension, or HELLP [hemolysis, elevated liver enzymes, and low platelet count] syndrome) but also can occur among patients with chronic hypertension who are developing superimposed preeclampsia with acutely worsening, difficult to control, severe hypertension. Acute-onset, severe hypertension that is accurately measured using standard techniques and is persistent for 15 minutes or more is considered a hypertensive emergency. It is well known that severe hypertension can cause central nervous system injury. Two thirds of the maternal deaths in the most recent Confidential Enquiries report from the United Kingdom for 2003–2005 resulted from either cerebral hemorrhage or infarction (5). The degree of systolic hypertension (as opposed to the level of diastolic hypertension or relative increase or rate of increase of mean arterial pressure from baseline levels) may be the most important predictor of cerebral injury and infarction. In a case series of 28 women with severe preeclampsia and stroke, all but one woman had severe systolic hypertension just before a hemorrhagic stroke, and 54% died, whereas only 13% had severe diastolic hypertension in the hours preceding a stroke (8). A similar relationship between severe systolic hypertension and risk of hemorrhagic stroke has been observed in nonpregnant adults (9). Thus, systolic blood pressure (BP) of 160 mm Hg or greater widely is included as part of the definition of severe hypertension in pregnant women or women in the postpartum period (10).

Box 2. Order Set for Severe Intrapartum
or Postpartum Hypertension Initial First-
Line Management With Hydralazine*

  • Notify physician if systolic blood pressure (BP) is greater than or equal to 160 mm Hg or if diastolic BP is greater than or equal to 110 mm Hg.
  • 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.
  • Institute additional BP timing per specific order.

*Please note there may be adverse effects and contraindications.

Data from National Heart, Lung, and Blood Institute. 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.

Pregnant women or women in the postpartum period with acute-onset, severe systolic hypertension; severe diastolic hypertension; or both require antihypertensive therapy. The goal is not to normalize BP, but to achieve a range of 140–150/90–100 mm Hg in order to prevent repeated, prolonged exposure of the patient to severe systolic hypertension, with subsequent loss of cerebral vasculature autoregulation. When this happens, maternal stabilization should occur before delivery, even in urgent circumstances (11). When acute-onset, severe hypertension is diagnosed in the office setting, the patient should be expeditiously sent to the hospital for treatment. Also, if transfer to a tertiary center is likely (eg, for preterm severe preeclampsia), BP should be stabilized and other measures initiated as appropriate, such as magnesium sulfate before transfer. Another risk for severe hypertension is endotracheal intubation, an intervention that is well known to increase BP sometimes to severe levels that require emergent therapeutic intervention (11). Induction of general anesthesia and intubation should never be undertaken without first taking steps to eliminate or minimize the hypertensive response to intubation. Close maternal and fetal monitoring by the physician and nursing staff are advised during the treatment of acute-onset, severe hypertension and judicious fluid administration is recommended even in the case of oliguria. After initial stabilization, the team should monitor BP closely and institute maintenance therapy as needed.

Recommendations

First-Line Therapy

Intravenous (IV) labetalol and hydralazine have long been considered first-line medications for the management of acute-onset, severe hypertension in pregnant women and women in the postpartum period. Although, relatively less information currently exists for the use of calcium channel blockers for this clinical indication, the evidence available suggests that oral nifedipine also may be considered as a first-line therapy (12–15). Some studies have shown that women who received oral nifedipine had their BP lowered more quickly than with either IV labetolol or hydralazine, and had a significant increase in urine output (12, 16). Concern for neuromuscular blockade and severe hypotension with the contemporaneous use of nifedipine and magnesium sulfate were not substantiated in a large retrospective review (17). However, because both drugs are calcium antagonists, careful monitoring is advisable.

Box 3. Order Set for Severe Intrapartum
or Postpartum Hypertension Initial First-
Line Management With Oral Nifedipine*

  • Notify physician if systolic blood pressure (BP) is greater than or equal to 160 mm Hg or if diastolic BP is greater than or equal to 110 mm Hg.
  • 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.

*Please note there may be adverse effects and contraindications.

†Capsules should be administered orally and not punctured or otherwise administered sublingually.

Data from National Heart, Lung, and Blood Institute. 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.

Patients may respond to one drug and not another. Magnesium sulfate is not recommended as an antihypertensive agent, but magnesium sulfate remains the drug of choice for seizure prophylaxis in severe preeclampsia and for controlling seizures in eclampsia. Box 1, Box 2, and Box 3 outline order sets for the use of labetalol, hydralazine, and nifedipine for the initial management of acute-onset, severe hypertension in women who are pregnant or in the postpartum period with preeclampsia or eclampsia (12–14, 16, 18). It is important to note differences in recommended dosage intervals between these options, which reflect differences in their pharmacokinetics. Although all three medications are appropriately used for the treatment of hypertensive emergencies in pregnancy, each agent can be associated with adverse effects. Parenteral hydralazine may increase the risk of maternal hypotension (systolic BP, 90 mm Hg or less) (19). Parenteral labetalol may cause neonatal bradycardia and should be avoided in women with asthma, heart disease, or congestive heart failure (20, 21). Nifedipine has been associated with an increase in maternal heart rate, and with overshoot hypotension (12). No significant changes in umbilical blood flow have been observed with the use of either labetalol or hydralazine (22), and maternal and perinatal outcomes are similar for both drugs (15). Likewise, no significant changes in the uteroplacental blood flow or the fetal heart have been noted with the use of nifedipine for severe pregnancy induced hypertension (23–25).

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 (6). The oral nifedipine algorithm also can be initiated in this setting as IV access is being obtained.

Second-Line Therapy

In the rare circumstance that IV bolus labetalol, hydralazine, or oral nifedipine fail to relieve acute-onset, severe hypertension and are given in successive appropriate doses such as those outlined in the order sets (see Box 1, Box 2, and Box 3), emergent consultation with an anesthesiologist, maternal–fetal medicine subspecialist, or critical care subspecialist to discuss second-line intervention is recommended. Second-line alternatives to consider include labetalol or nicardipine by infusion pump (26–28).

Sodium nitroprusside should be reserved for extreme emergencies and used for the shortest amount of time possible because of concerns about cyanide and thiocyanate toxicity in the mother and fetus or newborn, and increased intracranial pressure with potential worsening of cerebral edema in the mother (18). Once the hypertensive emergency is treated, a complete and detailed evaluation of maternal and fetal well-being is needed with consideration of, among many issues, the need for subsequent pharmacotherapy and the appropriate timing of delivery.

References

  1. American College of Obstetricians and Gynecologists. Hypertension in pregnancy. Washington, DC: American College of Obstetricians and Gynecologists; 2013.
  2. Kirkpatrick DH, Burkman RT. Does standardization of care through clinical guidelines improve outcomes and reduce medical liability? Obstet Gynecol 2010;116:1022–6. [PubMed] [Full Text]
  3. Menzies J, Magee LA, Li J, MacNab YC, Yin R, Stuart H, et al. Instituting surveillance guidelines and adverse outcomes in preeclampsia. Preeclampsia Integrated Estimate of Risk (PIERS) Study Group. Obstet Gynecol 2007;110:121–7. [PubMed] [Full Text]  
  4. von Dadelszen P, Sawchuck D, McMaster R, Douglas MJ, Lee SK, Saunders S, et al. The active implementation of pregnancy hypertension guidelines in British Columbia. Translating Evidence-Based Surveillance and Treatment Strategies (TESS) Group. Obstet Gynecol 2010;116:659–66. [PubMed] [Full Text]
  5. Cantwell R, Clutton-Brock T, Cooper G, Dawson A, Drife J, Garrod D, et al. Saving Mothers’ Lives: reviewing maternal deaths to make motherhood safer: 2006–2008. The Eighth Report of the Confidential Enquiries into Maternal Deaths in the United Kingdom. BJOG 2011;118(suppl 1):1–203. [PubMed] [Full Text]  
  6. Tuffnell DJ, Jankowicz D, Lindow SW, Lyons G, Mason GC, Russell IF, et al. Outcomes of severe pre-eclampsia/eclampsia in Yorkshire 1999/2003. Yorkshire Obstetric Critical Care Group. BJOG 2005;112:875–80. [PubMed] [Full Text]  
  7. Clark SL, Hankins GD. Preventing maternal death: 10 clinical diamonds. Obstet Gynecol 2012;119:360–4. [PubMed] [Full Text]  
  8. Martin JN Jr, Thigpen BD, Moore RC, Rose CH, Cushman J, May W. Stroke and severe preeclampsia and eclampsia: a paradigm shift focusing on systolic blood pressure. Obstet Gynecol 2005;105:246–54. [PubMed] [Full Text]  
  9. Lindenstrom E, Boysen G, Nyboe J. Influence of systolic and diastolic blood pressure on stroke risk: a prospective observational study. Am J Epidemiol 1995;142:1279–90. [PubMed]  
  10. Magee LA, Helewa M, Moutquin JM, von Dadelszen P. Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy. Hypertension Guideline Committee; Strategic Training Initiative in Research in the Reproductive Health Sciences (STIRRHS) Scholars. J Obstet Gynaecol Can 2008;30:S1–48. [PubMed]  
  11. Lyons G. Saving mothers’ lives: confidential enquiry into maternal and child health 2003–5. Int J Obstet Anesth 2008;17:103–5. [PubMed]  
  12. Vermillion ST, Scardo JA, Newman RB, Chauhan SP. A randomized, double-blind trial of oral nifedipine and intravenous labetalol in hypertensive emergencies of pregnancy. Am J Obstet Gynecol 1999;181:858–61. [PubMed]  
  13. Raheem IA, Saaid R, Omar SZ, Tan PC. Oral nifedipine versus intravenous labetalol for acute blood pressure control in hypertensive emergencies of pregnancy: a randomised trial. BJOG 2012;119:78–85. [PubMed] [Full Text]  
  14. Shekhar S, Sharma C, Thakur S, Verma S. Oral nifedipine or intravenous labetalol for hypertensive emergency in pregnancy: a randomized controlled trial. Obstet Gynecol 2013;122:1057–63. [PubMed] [Full Text]  
  15. Duley L, Meher S, Jones L. Drugs for treatment of very high blood pressure during pregnancy. Cochrane Database of Systematic Reviews 2013, Issue 7. Art. No.: CD001449. DOI: 10.1002/14651858.CD001449.pub3. [PubMed] [Full Text]  
  16. Rezaei Z, Sharbaf FR, Pourmojieb M, Youefzadeh-Fard Y, Motevalian M, Khazaeipour Z, et al. Comparison of the efficacy of nifedipine and hydralazine in hypertensive crisis in pregnancy. Acta Med Iran 2011;49:701–6. [PubMed] [Full Text]  
  17. Magee LA, Miremadi S, Li J, Cheng C, Ensom MH, Carleton B, et al. Therapy with both magnesium sulfate and nifedipine does not increase the risk of serious magnesium-related maternal side effects in women with preeclampsia. Am J Obstet Gynecol 2005;193:153–63. [PubMed] [Full Text]  
  18. National Heart, Lung, and Blood Institute. 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.   
  19. Report of the National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy. Am J Obstet Gynecol 2000;183:S1–S22. [PubMed] [Full Text]  
  20. Magee LA, Cham C, Waterman EJ, Ohlsson A, von Dadelszen P. Hydralazine for treatment of severe hypertension in pregnancy: meta-analysis. BMJ 2003;327:955–60. [PubMed] [Full Text]  
  21. Magee LA, von Dadelszen P. The management of severe hypertension. Semin Perinatol 2009;33:138–42. [PubMed] [Full Text]  
  22. Baggio MR, Martins WP, Calderon AC, Berezowski AT, Marcolin AC, Duarte G, et al. Changes in fetal and maternal Doppler parameters observed during acute severe hypertension treatment with hydralazine or labetalol: a randomized controlled trial. Ultrasound Med Biol 2011;37:53–8. [PubMed] [Full Text]  
  23. Lurie S, Fenakel K, Friedman A. Effect of nifedipine on fetal heart rate in the treatment of severe pregnancy-induced hypertension. Am J Perinatol 1990;7:285–6. [PubMed]  
  24. Scardo JA, Vermillion ST, Hogg BB, Newman RB. Hemodynamic effects of oral nifedipine in preeclamptic hypertensive emergencies. Am J Obstet Gynecol 1996;175:336–8; discussion 338–40. [PubMed] [Full Text]  
  25. Moretti MM, Fairlie FM, Akl S, Khoury AD, Sibai BM. The effect of nifedipine therapy on fetal and placental Doppler waveforms in preeclampsia remote from term. Am J Obstet Gynecol 1990;163:1844–8. [PubMed]  
  26. Labetalol hydrochloride - oral. In: Drug facts and comparisons. St. Louis (MO): Wolters Kluwer Health; 2014. p. 886–9.  
  27. Vadhera RB, Pacheco LD, Hankins GD. Acute antihypertensive therapy in pregnancy-induced hypertension: is nicardipine the answer? Am J Perinatol 2009;26:495–9. [PubMed] [Full Text]  
  28. Nij Bijvank SW, Duvekot JJ. Nicardipine for the treatment of severe hypertension in pregnancy: a review of the literature. Obstet Gynecol Surv 2010;65:341–7. [PubMed]  

Copyright February 2015 by the American College of Obstetricians and Gynecologists, 409 12th Street, SW, PO Box 96920, Washington, DC 20090-6920. All rights reserved.

ISSN 1074-861X

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.

American Congress of Obstetricians and Gynecologists
409 12th Street SW, Washington, DC  20024-2188 | Mailing Address: PO Box 70620, Washington, DC 20024-9998