Severe Hypertension in Pregnancy: Am I still giving Mag?

Good morning everyone,

I received a great question from one of our Academy members based on a practice question he was trying to answer that I suspect others will have too, so I want to cover it with everyone.

The question pertains to the management of severe pregnancy induces hypertension and how this question should be answer on the FP-C and CCP-C exam.

Here's the scenario.

Here's the question.

Ok, SAT (referring to the ACE SAT book by Will Wingfield) books says Labetalol, Back to Basics book says Mag... What is BCCTPC wanting?

While I can't say for sure what the BCCTPC is looking for, I do know they claim the exams are kept up-to-date with current published practices guidelines.  So, based on that, this is my answer to the question...

  • First, remember, the primary goal when managing severe pregnancy induced hypertension (or preeclampsia) is the reduction of blood pressure, not necessarily the prevention of seizures, although this can be a side effect of managing the BP, but not always.

  • Treatment of PIH and Preeclampsia is just a temporizing intervention, and generally will not stop the progression of the condition. Only delivery of the baby can completely resolve the condition.

That being said...

The use of Magnesium Sulfate for Preeclampsia and Eclampsia is still fairly common in most prehospital systems, and is an acceptable treatment option in that setting, however, in the critical care environment where providers have access to an expanded drug formulary and scope of practice other medications have been shown more effective.

Based on the most recent literature I could find from UpToDate, the American College of Emergency Physicians Critical Care Transport text, and a 2015 Opinion Paper from the American College of Obstetricians and Gynecologists *  the current recommendation for the treatment of severe pregnancy induces hypertension (SBP > 160 or DBP >110) is to initially manage with Labetalol 20mg IVP over 2-5 min, repeated at 40mg, then 80mg q 10 minutes if BP remains above threshold level.

If BP threshold is still exceeded after Labetalol dosing, Hydralazine 5-10mg over 2 minutes (max total dose 20mg).

If blood pressure still remains above threshold, contact medical control for guidance.

Magnesium Sulfate has been shown to be a poor antihypertensive medications and tocolytic, but is still considered an appropriate medication for the treatment of pregnancy induces seizures, although dosing regimens do vary.

So, to sum it all up...

To the best I can tell, initial management of severe PIH (SBP >160 or DBP >110) should start with labetalol (20mg, 40mg, 80mg), then switch to hydralazine (5-10mg). If pt seizes, treat with Mag bolus (6g over 10) followed by 2g/hr infusion, or Ativan.

* Opinion Paper on the Emergent Treatment of Sever Hypertension During Pregnancy

You can find more content like this in our FP-C Review Curse over at the Academy.

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