Keith Balderston MD
Directory MFM Sacred Heart Medical Center
New Waze to View Old Problem
• Learning Objectives
 Define hypertensive emergencies
 How to approach the blood pressure
 Select the best treatment options based on blood
pressure parameters
 Nothing to disclose
Background
 Hypertension affects 10% of all pregnancies
 Accounts for 15%of maternal mortality(second leading
cause)
 Leads to significant morbidity
 Stroke, abruption, encephalopathy, MI, renal damage,
post op bleeding, heart failure
Definition
 Diastolic BP >110-120
 MAP(mean arterial pressure) acute rise by > 30 mm
Hg
 MAP = DP + 1/3 PP
 PP( pulse pressure)= SP-DP
 120/80 = PP 40
Definitions
 MAP = perfusion pressure to organs
Cardiac
output
P
resistance
 CO = SV x HR
 PP = stroke volume + compliance
 BP = Flow x resistance
Hypertension
 Increased flow
 Increased resistance
 Combination of both
 What one is the biggest culprit?
Increased Flow
 Hypervolemia
 Increased cardiac output
 Increased cardiac contractility
Increased Resistance
Increased Catachols
Amphetamines
Cocaine
Pain
ICP elevation
Hypoxia
Hypercarbia
Endocrine/humoral
Elevated renin
Elevated thyroid
Toxemia
Pheo
Vasopressin
Endothelin
ANP
Tale of Two Patients
 #1 30 yo G1 at 33 weeks
 Admitted severe toxemia
 BP = 165/115
 Treatment ordered = hydralazine
 #2 44 yo G2P1
 Induction 38 weeks DM, renal disease
 BP = 180/100
 Treatment = Labetalol then Lasix
Gestalt of the BP
 BP = flow x resistance
 SBP = Flow
 Interaction between SV and vasoconstriction
 DBP = Resistance
 Degree of vasoconstriction
 PP used to determine if flow is abnormal
 PP = ½ SV
 Best clue where to start
Sammy Haugen
Pulse Pressure Pearls
 Narrow PP
 Occult bleeding, dehydration
 Wide PP
 Hypervolemia
 Acute aortic dissection
 Can look at prior to Epidural to make sure appropriate
preload
Cases
 18 yo G1 35 weeks 4+ protein
 Preeclampsia
 HA, epigastric pain
 Active labor , Mg 2 g per hour
 BP 165/110
 Category 1 tracing
What is Main Problem
 Is BP elevated = yes
 165 – 110 = 55
 Pulse pressure 55 thus no ticket
 DBP = 110 showing significant vasoconstriction
 #1 problem Increased resistance (vasoconstriction)
likely from toxemia
 Treatment : Vasodilator hydralazine
• Caution with Nifedipine as on Mg
Case # 2
 44 yo G1 P1 5 days post op
 Obese GDM CHTN
 Failed induction
 Labs normal
 Labetalol 400 mg TID (has been increased daily)
 BP 185/ 100
What is Main Problem
 185 – 100 = 85
 Ticket = Yes
 Pulse Pressure = 85 Significantly Increased Volume
 #1 problem is increased flow likely from hypervolemia
obesity and long failed induction
 Treatment : Already on large dose Beta blocker thus
LASIX now needed
Summary
 Definition
 MAP acute increase > 30 mm Hg
 DBP > 110-120
 Urgency to treat
 Abruption, stroke , MI, renal damage
Summary
 Physiology / Gestalt of BP
 BP = F x R


Increased Flow ( hypervolemia, elevated cardiac output and
contractility)
Increased resistance = vasoconstriction
Summary
 Treatment
 Make a problem based approach

Is it flow or resistance or both
 Medication



Beta blockers – Labetalol esmolol if drip
Loop diuretics Lasix
Vasodilators
 Hydralazine
 Ca Cannel blockers
 Sodium Nitroprusside
 Nitroglycerine