Pocket ObGyn – Gestational Hypertensive Disorders
See Abbreviations
Definition and see Chap. 12 (Hypertension in Pregnancy, ACOG Task Force, 2013).
- Chronic HTN: SBP ³140 or DBP ³90 prior to Preg, prior to 20 w gest, or persisting longer than 12 w postpartum
- Gestational HTN: SBP ³140 or DBP ³90 after 20 w w/o proteinuria
- Preeclampsia: New onset HTN (as below) w or w/o proteinuria >20 w
Nonsevere: SBP ³140 or DBP ³90; proteinuria ³300 mg/24 h (or 1+ urine dip or protein: creatinine ratio ³0.3)
Sev: SBP ³160 or DBP ³110; proteinuria ³5 g/24 h (or 3+ urine dip); oliguria <500 mL/24 h; sx such as HA, visual changes, difficulty breathing, or RUQ pain; elevated liver fxn tests, low Plts. Preeclampsia can ® eclampsia. Newest guidelines do not use proteinuria to rule out preeclampsia. New onset HTN with sxs = diagnosis [thrombocytopenia (<100,000/uL) or serum Cr >1.1 mg/dL or elevated LFTs (2´ upper limit normal) or pulmonary edema or cerebral/visual symptoms].
- Chronic HTN w/ superimposed preeclampsia: Worsening HTN w/ new onset proteinuria
- All BP should be taken on 2 occasions 4 h apart (after pt has been seated quietly for several minutes, cuff level w/ heart). Also see HELLP (Chap. 15) & Eclampsia (Chap. 18).
See detailed discussion and management of these disorders in Chap. 12. Epidemiology and Etiology
- Preeclampsia found in ~7% of True cause unk.
- Risk factors: Age <18 or >40; nulliparity; h/o preeclampsia, FHx of preeclampsia
- Poss causes: Endothelial damage, altered metabolism, inflammation, oxidative stress
Clinical Manifestations
- Preeclampsia: HA, visual changes (scotomata, photophobia), edema, abdominal pain (specifically epigastric or RUQ). Often
Physical Exam
- Perform full neurologic exam: Evaluate for HA, visual changes, clonus
- Palpate abd to assess abdominal tenderness (specifically RUQ)
- Visualize/palpate extremities to evaluate for periph edema
Diagnostic Workup/Studies
- CBC, CMP (evaluate liver & renal fxn), assessment of proteinuria (by spot prot to Cr ratio, urinalysis, or 24 h urine collection)
- CT can show cerebral edema in the post hemispheres, a form of PRES (Post reversible encephalopathy syn)
Treatment and Medications
- Acute HTN (Chest 2007; 131:1949; Obstet Gynecol 2011;118:1465):
Labetalol: 20 mg IV, rpt at 10-min intervals, double dose w/ max dose of 80 mg at one given time; total max dose of 300 mg (eg, 20 mg ® 40 mg ® 80 mg ® 80 mg ® 80 mg)
Hydralazine: 5 mg IV over 1–2 min, rpt at 20 min intervals, max dose at one time of 20 mg; not 1st line as can see mat HoTN
Nifedipine: 10–20 mg PO q30min
Nitroprusside: 0.20-4 mcg/kg/min iv drip, titrate to effect. Only in critical illness resistant to max dose of other agents. Risk of cyanide toxicity with prolonged use.
Nicardipine: 2.5 mg/h IV titrating, do not exceed 15 mg/h
DO NOT USE: ACEI, or ARB
Goal: ¯ risk of mat stroke but maintain pres for placental perfusion
• Oral, outpt treatments
Labetalol: 100–800 mg PO BID–TID (max dose 2400 mg/24 h)
Methyldopa: 250 mg PO BID (max dose 3 g/24 h)
Nifedipine XR: 30–90 mg PO daily (max dose 120 mg/24 h)
• Preeclampsia with severe features, or chronic HTN w/ superimposed preeclampsia
Magnesium sulfate (MgSO4): Bolus 4–6 g IV w/ maintenance of 1–2 g/h for sz prevention, titrate and consider no bolus if pt has renal failure
Goal magnesium level = 4–6 mg/dL
Monit closely for pulm edema as MgSO4 is a smooth muscle relaxer
- Timing for deliv based on limited scientific evid & should always be dependent upon the individualized clinical picture (Obstet Gynecol 2011;118:327)
Chronic HTN: On no meds (38–39 w), controlled on meds (37–39 w), not well controlled on meds (36–37 w)
Gestational HTN: 37–38 w
Preeclampsia: Nonsevere (37 w), sev (at time of dx if ³34 w, otherwise dependent upon clinical picture)