- Rapid Reference
- Presentation & diagnosis
- Questions & discussion
- PDF of this chapter (or create customized PDF)
- Glucose, electrolytes including Ca/Mg/Phos.
- CBC, liver function tests, ammonia.
- INR, PTT, fibrinogen, D-dimer, LDH, haptoglobin.
- Urinalysis and spot protein/creatinine ratio.
- If infection suspected: cultures.
- OB ultrasound (e.g., if abruption possible).
- Neuro/visual changes: may consider CT/MRI brain (r/o ICH) or retinal exam (r/o detachment).
- Right upper-quadrant pain: US to exclude subcapsular liver hematoma.
Bp control (more)
- If the MAP is >120 mm, then the initial goal is to drop the MAP by ~20% over a few hours. Subsequently, the MAP may be gradually reduced to a target of ~105-115 mm.
- For severe hypertension, nicardipine infusion may provide more powerful, predictable, and titratable efficacy.
- For milder hypertension, intermittent boluses of IV labetalol may be adequate.
- (See table of antihypertensive agents below.👇)
magnesium infusion (more)
- Load with 6 grams IV (24 mM).
- Maintenance regimen:
- Cr <1 mg/dL: 2 grams/hr gtt (8 mM/hr).
- Cr 1-2.5 mg/dL: 1 gram/hr gtt (4 mM/hr).
- Cr >2.5 mg/dL: No infusion, PRN boluses.
- Watch for: oliguria, loss of reflexes, respiratory muscle weakness.
- 🎯 Therapeutic target & monitoring:
- Fetal monitoring.
- ? Steroid for lung maturation.
- ? Expedited delivery.
presentation & diagnosis
- Very common among critically ill pregnant women.
- Usually occurs between 20 weeks of gestation and about 6 weeks postpartum.
- Rarely can occur earlier than 20 weeks in patients with molar pregnancies.
- A key clue is hypertension, but patients may not be impressively hypertensive in an absolute sense.
- Common risk factors for preeclampsia:
- History of preeclampsia, renal disease, hypertension, diabetes, obesity.
- Thrombophilia, lupus, antiphospholipid antibody syndrome.
- Age >40, multifetal pregnancy.
clinical findings of preeclampsia may include:
- Pulmonary edema.
- Pitting edema – especially involving hands and face (non-dependent edema, suggesting endothelial dysfunction).
- Acute kidney injury, oliguria.
- Epigastric or right upper-quadrant discomfort.
- Hypertensive encephalopathy with vision changes & headache.
- Intracranial hemorrhage.
- Hyperreflexia (sometimes with clonus).
lab panel for pregnant ICU admission
- Electrolytes including Ca/Mg/Phos.
- Complete blood count.
- Liver function tests & ammonia.
- Coags, D-dimer, and fibrinogen (note that normally, fibrinogen is elevated in pregnancy).
- LDH and haptoglobin.
- Urinalysis and spot urine protein/creatinine ratio.
- If febrile/hypotensive: lactate, blood cultures, procalcitonin.
- Useful reference on normal lab values in pregnancy: Perinatology.com.
definition of preeclampsia
-  HTN developing or worsening >20 weeks after gestation, including either:
- SBP >160 or DBP >110 (persistent over >15 minutes).
- SBP > 140 or DBP >90 (persistent over >4 hours).
-  Plus ANY of the following (🔑 proteinuria isn't required for the diagnosis.)(32443079)
- Proteinuria >0.3 g/day.
- Reasonable surrogate measure is a spot urine protein/creatinine ratio >0.3 mg/mg.
- Urine dipstick showing proteinuria is nonspecific, but a negative dipstick can usually be accepted as excluding significant proteinuria.(29803330) Alternatively, 2+ or greater proteinuria strongly suggests clinically significant proteinuria.(34051884)
- Acute kidney injury: Cr > 1.1 mg/dL or doubling of baseline value (note that creatinine is normally <0.8 mg/dL in pregnancy).
- Cerebral or visual disturbance (including severe headache refractory to acetaminophen, seizure, delirium, clonus).
- Pulmonary edema.
- Transaminitis above twice normal.
- Thrombocytopenia <100,000/mm3.
- Severe, persistent abdominal pain in the right upper quadrant or epigastrium which is otherwise unexplained.
- Proteinuria >0.3 g/day.
-  Exclusion of alternative diagnoses, for example:
- Alternative cause of renal failure (e.g. glomerulonephritis).
- Alternative cause of hypertensive emergency (e.g. thyroid storm, cocaine).
- Primary CNS disease (e.g. meningitis, CVA).
- EtOH withdrawal.
- Other types of microangiopathic hemolytic anemia (e.g., thrombotic thrombocytopenic purpura, hemolytic uremic syndrome).
diagnosis of HELLP syndrome (Hemolysis, Elevated LFTs, Low Platelets)
- HELLP is a manifestation of preeclampsia (not a separate disorder).(29803330) It's a thrombotic microangiopathy which may be closely related to atypical hemolytic uremic syndrome.
- Clinical symptoms may include nausea/vomiting and right upper-quadrant pain.
- Laboratory findings:
- Microangiopathic hemolytic anemia (e.g. high LDH, low haptoglobin, schistocytes on blood smear)
- Elevated AST and ALT (above twice the upper limit of normal).
- Platelets <100,000/mm3.
- May cause hepatic hematoma that ruptures, leading to hemoperitoneum.
- Differential diagnosis includes pregnancy-induced thrombotic thrombocytopenic purpura (TTP) and acute fatty liver of pregnancy.
- Treatment of HELLP is discussed below.
HTN & volume management
blood pressure targets
- General strategy:
- Antihypertensives are generally indicated if SBP>160 or DBP>105 (MAP >120).
- (#1) The initial goal is decreasing MAP by ~20%.
- (#2) Subsequently, the blood pressure should be gradually decreased to a target MAP of roughly ~100-115 mm. This target should be individualized to a certain extent, depending on the baseline blood pressure.
- The optimal target is unclear:
- Lowering blood pressure prevents end-organ hypertensive damage (e.g., intracranial hemorrhage).
- Excessive blood pressure drop may cause hypoperfusion (including the placenta). Placental hypoperfusion may stimulate the release of vasoconstrictive/inflammatory factors, which aggravate the underlying disease process.
initial antihypertensive for rapid blood pressure control
- Nicardipine infusion
- Traditionally the first-line agent.
- Given long half-life of labetalol, it may be most sensible to administer as sequential boluses (see below).
- Nitroglycerine infusion
- Especially useful in patients with cardiogenic pulmonary edema.
- IV hydralazine
- Not usually preferred, due to the capacity to cause unpredictable and prolonged drops in blood pressure.(14576246)
- Oral nifedipine immediate release
- Although traditionally avoided in hypertensive emergencies, recent studies have shown that oral nifedipine is a potential treatment of preeclampsia.(29884955)
- If nifedipine is used, safety may be improved by spacing out doses sufficiently. Also note that the tablet must be swallowed whole (not administered sublingual or chewed or broken open).
- Start oral antihypertensives once hemodynamically stabilized and improving. Unfortunately, many antihypertensives aren't suitable for pregnancy.
- Labetalol is traditionally the first-line agent (especially for patients who responded to IV labetalol).
- Start 200 mg PO BID.
- Escalate dose gradually, until no longer requiring IV labetalol doses.
- Extended-release nifedipine is another excellent option (especially for patients who responded to IV nicardipine).
- Other options that are safe for pregnancy include hydralazine, prazosin, clonidine, and methyldopa.
- Preeclampsia causes endothelial damage, leading to third-spacing of fluids. This creates a very challenging situation, where patients are often intravascularly depleted. Unfortunately, administered fluid will generally rapidly extravasate into the tissues (causing harm rather than benefit).
- Some fluid might be reasonable to support perfusion among patients who are NPO (e.g., ~50 ml/hr of 5% dextrose in half-normal saline). However, large volumes should be avoided, as this may promote pulmonary edema.
- Avoid chasing oliguria with large volume of fluid. If oliguria doesn't respond to a small fluid bolus (300 ml), additional fluid may be inadvisable.(27708700)
magnesium infusion for seizure prophylaxis
- Magnesium should be given to any critically ill, preeclamptic woman to reduce risk of seizure (unless contraindicated by myasthenia gravis, heart block, or severe hypocalcemia).
- Magnesium levels aren't routinely monitored in women with normal renal function. If levels are checked, they may be interpreted roughly as shown below.(30575675)
- ⚠️ Make sure to use the appropriate units! There are three different units in clinical use, so it's easy to get confused.
- If you are going to check magnesium levels, consider also checking electrolytes and calcium as well.
- The optimal duration of the magnesium infusion is unclear. Treatment is often continued until ~24 hours after delivery, when the patient is showing clinical signs of resolving preeclampsia.
- Load with 6 grams IV magnesium sulfate (24 mM).
- Infuse magnesium at 1-2 grams/hour (4-8 mM/hour)(some newer data and guidelines suggest that 1 gram/hour may be adequate).(29803330, 26485229, 34051884)
- 2 grams/hour (8 mM/hr) – may be more appropriate for higher weight & antepartum patients.
- 1 gram/hour (4 mM/hr) – may be more appropriate if mild renal insufficiency (Cr 1-2.5) and/or mild oliguria.
- Monitor carefully. Hold the infusion and check levels if signs of magnesium toxicity or renal failure:
- Signs of magnesium toxicity: loss of patellar reflexes, tachypnea due to respiratory muscle weakness.
- Reduced urine output: acute kidney injury will eventually lead to magnesium accumulation.
treatment with severe oliguria or creatinine >2.5 mg/dL
- Load with 4-6 grams IV magnesium sulfate (16-24 mM).
- Follow electrolytes & magnesium levels q4-6hr.
- Bolus with magnesium based on levels (don't use a maintenance infusion).
- Common side-effects include flushing, mild hypotension, and muscle weakness.
- Severe magnesium toxicity may cause respiratory depression or heart block. The treatment is IV calcium.
- Magnesium can suppress parathyroid hormone production, leading to symptomatic hypocalcemia. Treatment is cessation of the magnesium infusion and administration of IV calcium.
- Most eclamptic seizures are self-limited.
- Magnesium is the front-line antiepileptic to prevent seizure recurrence.
- If patient hasn't yet received magnesium, load with 6 grams IV and infuse as above.
- If patient has received magnesium, consider re-loading with 2-4 grams IV.
- Infusion or maintenance doses as described above.
- Benzodiazepine may be used for status epilepticus (e.g., ongoing generalized seizure >5 minutes).
- IV access: Lorazepam 0.1 mg/kg IV bolus
- No IV access: Midazolam 10 mg IM
seizure refractory to benzodiazepine & magnesium
- This is unusual and may suggest another process (e.g. intracranial hemorrhage).
- Consider early intubation and propofol infusion.
- Levetiracetam may be added as a second-line agent after magnesium.
- More on the management of status epilepticus here.
diagnostics & neuroimaging
- Check fingerstick glucose immediately, to exclude hypoglycemia. Obtain a full laboratory panel, if not recently performed.
- Consider imaging to exclude other pathology (e.g., intracranial hemorrhage, cerebral venous thrombosis). Patients with eclampsia will often have imaging features of PRES, as these two conditions overlap substantially.
- More on PRES here.
treatment of HELLP syndrome
don't forget the treatment for preeclampsia!
- HELLP is a subset of preeclampsia. Therefore, patients with HELLP also have preeclampsia
- Magnesium infusion is indicated in HELLP syndrome, as these patients are at risk for seizure.
- If hypertension is present, it should be treated in the same fashion as preeclampsia in general (see above).
subcapsular liver hematoma
- This should be suspected in any patient with preeclampsia/HELLP with RUQ pain.
- Diagnosis is based on ultrasonography.
- Treatment includes optimization of coagulation factors, large bore IV access, emergent surgery and/or angiographic embolization to treat hepatic rupture, and potentially even liver transplant.
- Get all hands on deck early (e.g., trauma surgeons with expertise in liver injury and transplant teams).
- Growing evidence indicates that HELLP could share many similarities with atypical hemolytic uremic syndrome (aHUS), which is caused by dysregulated complement activation.(29717384, 26921648)
- One case report describes successful treatment of HELLP with eculizumab (a complement inhibitor).(30159857) This might be considered in cases of HELLP which closely resemble atypical hemolytic uremic syndrome (e.g., prominent microangiopathic hemolytic anemia with low complement levels).
delivery & post-delivery course
- As with preeclampsia in general, severe HELLP is an indication for delivery.
- Deterioration may continue for two days after delivery, but improvement should subsequently occur. If deterioration continues for four days after delivery, consider alternative diagnostic possibilities (e.g. atypical hemolytic uremic syndrome, thrombotic thrombocytopenic purpura).(30575675)
fetal monitoring & delivery
- As per Obstetrics team.
- 💡 Note that the fetus is a maternal end-organ, so fetal distress can be an early sign of systemic hypoperfusion (shock).
- If fetal stress is a symptom of maternal shock, then both delivery and maternal resuscitation may be required simultaneously.
- Definitive treatment of preeclampsia/HELLP is delivery of the fetus.
- If expedited delivery is possible and the fetus is pre-term (<37 weeks), consider steroid administration to promote fetal lung maturity.
- This decision will be made by obstetrics. Indications for delivery may include:
- Gestational age >37 weeks (term pregnancy).
- Refractory HTN despite three classes of antihypertensive agents.
- Progressive thrombocytopenia.
- Progressively worse renal or liver tests.
- Pulmonary edema.
- Worsening neurologic features (e.g., intractable headache, repeated visual scotomata, or seizures).
- Non-reassuring fetal status, suspected placental abruption, rupture of membranes.
disseminated intravascular coagulation (DIC)
- Follow coagulation studies.
- Factor replacement may be needed prior to delivery or if there is active bleeding.
- Note that fibrinogen targets in post-partum hemorrhage may be somewhat higher than in most patients (e.g., >200 mg/dL).
- Consider whether DIC may be caused by placental abruption.(29747734)
acute kidney injury
- Management is generally supportive (more on the management of AKI here 🚀).
- Consider other possible causes of kidney injury including glomerulonephritis, thrombotic thrombocytopenic purpura, or atypical hemolytic uremic syndrome. These may require specific treatment.
- Perfusion should be optimized as discussed above, with cautious use of fluids. However, these patients often have leaky capillaries, so large-volume fluid resuscitation is often counterproductive (merely worsening pulmonary and systemic edema).(26412014)
other complications to be aware of
- Intracranial hemorrhage.
- Retinal detachment.
- Preeclampsia, immobility, and pregnancy are all risk factors for venous thromboembolism.
- DVT prophylaxis should be determined in coordination with the Obstetrics team, as this may affect spinal anesthesia & delivery.
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questions & discussion
To keep this page small and fast, questions & discussion about this post can be found on another page here.
- Failure to consider preeclampsia (preeclampsia may occur even in absence of proteinuria).
- IV hydrazine may cause precipitous drop in blood pressure, so try to avoid this when possible.
- Excessive volume administration in attempts to stimulate urine output.
- Failure to obtain an adequate laboratory panel (e.g., leading to a missed diagnosis of HELLP syndrome).
- ACOG Practice Bulletin 2019: Gestational HTN & preeclampsia
- Preeclampsia & eclampsia (Chris Nickson, LITFL)
- Preeclampsia & eclampsia (Anand Swaminathan and Jenny Beck-Esmay, CoreEM)
@kat__evans “1/3 all eclampsia cases occur in the postpartum stage. If a pt of child bearing age presents with a first time seizure, could this be preeclampsia? Think, could this pt be postpartum? Investigate, is the pt lactating, is there a recent C-section scar?” #SMACC #badEM
— Amy Gomes (Craike) (@AmesCraike) March 27, 2019
Kat Evans at #SMACC discussed women presenting with eclampsia/preeclampsia in an emergency setting do not need IV crystalloids. Receiving enough with IV meds. High risk of fluid overload and Pulmonary Oedema. #INFiLL pic.twitter.com/ausPuGAMo2
— Bel Bruce (@BelRBruce) March 27, 2019
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- 16269975 Hanff LM, Vulto AG, Bartels PA, Roofthooft DW, Bijvank BN, Steegers EA, Visser W. Intravenous use of the calcium-channel blocker nicardipine as second-line treatment in severe, early-onset pre-eclamptic patients. J Hypertens. 2005 Dec;23(12):2319-26. doi: 10.1097/01.hjh.0000188729.73807.16 [PubMed]
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- 26485229 Pratt JJ, Niedle PS, Vogel JP, Oladapo OT, Bohren M, Tunçalp Ö, Gülmezoglu AM. Alternative regimens of magnesium sulfate for treatment of preeclampsia and eclampsia: a systematic review of non-randomized studies. Acta Obstet Gynecol Scand. 2016 Feb;95(2):144-56. doi: 10.1111/aogs.12807 [PubMed]
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- 29803330 Brown MA, Magee LA, Kenny LC, Karumanchi SA, McCarthy FP, Saito S, Hall DR, Warren CE, Adoyi G, Ishaku S; International Society for the Study of Hypertension in Pregnancy (ISSHP). The hypertensive disorders of pregnancy: ISSHP classification, diagnosis & management recommendations for international practice. Pregnancy Hypertens. 2018 Jul;13:291-310. doi: 10.1016/j.preghy.2018.05.004 [PubMed]
- 29884955 Watson K, Broscious R, Devabhakthuni S, Noel ZR. Focused Update on Pharmacologic Management of Hypertensive Emergencies. Curr Hypertens Rep. 2018 Jun 8;20(7):56. doi: 10.1007/s11906-018-0854-2 [PubMed]
- 30159857 Sarno L, Tufano A, Maruotti GM, Martinelli P, Balletta MM, Russo D. Eculizumab in pregnancy: a narrative overview. J Nephrol. 2019 Feb;32(1):17-25. doi: 10.1007/s40620-018-0517-z [PubMed]
- 30575675 ACOG Practice Bulletin No. 202: Gestational Hypertension and Preeclampsia. Obstet Gynecol. 2019 Jan;133(1):1. doi: 10.1097/AOG.0000000000003018 [PubMed]
- 32443079 Gestational Hypertension and Preeclampsia: ACOG Practice Bulletin, Number 222. Obstet Gynecol. 2020 Jun;135(6):e237-e260. doi: 10.1097/AOG.0000000000003891 [PubMed]
- 34051884 Chappell LC, Cluver CA, Kingdom J, Tong S. Pre-eclampsia. Lancet. 2021 May 27:S0140-6736(20)32335-7. doi: 10.1016/S0140-6736(20)32335-7 [PubMed]