PIH Disorders

Question 1

severe features of preeclampsia

Answer 1

persistent severe SBP >160 or DBP>110, thrombocytopenia (Plt <100k), LFTs > 2x ULN, creatinine >1.1 or 2x baseline, pulmonary edema, intractable headache, visual disturbances

Question 2

Definition of persistent severe range BP

Answer 2

SBP >160 or DBP>110 measured on two occasions, 15-60 min apart (do not have to be consecutive blood pressures)

Question 3

When do you initiate treatment of a severe blood pressure?

Answer 3

If it has been sustained for at least 15 min, then initiate treatment (Labetalol if HR >60 and IV In place or Nifedipine if HR <100 and no IV in place). Goal of time to treatment is <60 min.

Question 4

What is magnesium used for?

Answer 4

raises the seizure threshold. If <32 weeks then it is also used for fetal neuroprotection (consider higher loading dose of 6g). Not considered an anti-hypertensive medication.

Question 5

How do you give magnesium if you don’t have IV access?

Answer 5

can give 10g in 50% solution IM (5g in each buttock)

Question 6

contraindications to magnesium

Answer 6

pulmonary edema, myasthenia gravis, renal failure

Question 7

Anticonvulsants and doses when magnesium is contraindicated

Answer 7

Anticonvulsants (for recurrent seizures or when magnesium is C/I):
* Lorazepam: 2-4 mg IV x 1, may repeat x 1 after 10-15 min
* Diazepam: 5-10 mg IV every 5-10 min to max dose 30 mg
* Phenytoin: 15-20 mg/kg IV x 1, may repeat 10 mg/kg IV after 20 min if no response. Avoid with hypotension,
may cause cardiac arrhythmias.
* Keppra: 500 mg IV or orally, may repeat in 12 hours. Dose adjustment needed if renal impairment.

Question 8

PO options for anti-hypertensive agents when IV is not available yet

Answer 8

Immediate-release Nifedipine (10mg) or Labetalol (200mg)

Question 9

BP targets with anti-hypertensive agents

Answer 9

SBP 140-150, DBP 90-100

Question 10

Labetalol Algorithm

Answer 10

Sustained BP >160/110 –> Labetalol 20mg IV –> recheck BP in 10 min –> BP >160/110 –> Labetalol 40mg IV –> recheck BP in 10 min –> BP >160/110 –> Labetalol 80mg IV –> recheck BP in 10 min –> BP >160/110 –> switch to Hydralazine –> Recheck BP in 20 min –> BP >160/110 –> consult MFM

If BP <160/110 at any point, hold further meds and continue to monitor

Question 11

contraindications to labetalol

Answer 11

active asthma (weekly symptoms or use of inhaler/steroids for asthma during pregnancy or hx of intubation/hospitalization for asthma), heart disease, CHF

Question 12

Max dose of labetalol

Answer 12

do not exceed 300 mg in 24 hours

Question 13

Hydralazine algorithm

Answer 13

Sustained BP >160/110 –> Hydralazine 5-10mg –> repeat BP in 20 min –> sustained BP >160/110 –> Hydralazine 10mg –> repeat BP in 20 min –> sustained BP >160/110 –> switch to Labetalol 20mg –> repeat BP in 10 min –> sustained BP >160/110 –> consult MFM, give Labetalol 40mg

Question 14

Nifedipine IR Algorithm

Answer 14

Sustained BP >160/110 –> PO Nifedipine 10mg –> repeat BP in 20 min –> sustained BP >160/110 –> PO Nifedipine 20mg –> repeat BP in 20 min –> sustained BP >160/110 –> PO nifedipine 20mg –> repeat BP in 20 min –> sustained BP >160/110 –> change to IV Labetalol 20 mg –> repeat BP in 10 min –> sustained BP >160/110 –> consult MFM

Question 15

BP monitoring after achievement of goal BP <160/110

Answer 15

Repeat BP q10m x1 hr, q15 min x 1 hr, q30min x1 hr, then q4h