2. Hypertensive disease is the 4th
leading cause of
maternal death
Preeclampsia complicates about upto 8% of
pregnancies
In U.S preeclampsia complicates approx 7-10%
of pregnancies
Eclampsia 1 in 10000-150000 pregnancies
Severe PIH contributes to 20-40% of maternal
deaths & 20% of perinatal deaths
4. Defined as a systolic BP >140 mm Hg or
diastolic BP >90 mm Hg
OR
a constant increase in systolic or diastolic BP
by 30 mmHg & 15 mm Hg respectively above
patient’s baseline
5. Classic Triad of Preeclampsia - Hypertension
Proteinuria, Edema
Defined as hypertension occuring after 20
wks gestation or in early postpartum period
& returned to normal within 3 months after
delivery
OR
Onset after 20wks gestation & atleast one of
the following
6. Proteinuria >300 mg/24 hr
Oliguria /serum plasma creatinine ratio >0.09mmol/L
Headaches with hyperreflexia,eclampsia,clonus,or visual
disturbances
Increased liver enzymes , plasma glutathione S-transferase –
alpha 1-1, or serum alanine aminotransferase or right
quadrant pain
Thrombocytopenia,increased LDH, haemolysis, DIC
Intrauterine growth retardation
7. SBP > 160 mm Hg
DBP > 110 mm Hg
Proteinuria > 5 g/24° or
3-4+ on dipstick
Oliguria < 500 cc/24°
↑ serum creatinine
Pulmonary edema or
cyanosis
CNS symptoms (HA,
vision changes)
Abdominal (RUQ) pain
Any feature of HELLP
hemolysis
↑ liver enzymes
thrombocytopenia
IUGR or oligohydramnios
8.
9. Nulliparity(Elderly & young primigravida)
Chronic renal disease(Nephritis)
Angiotensin gene T235
Chronic hypertension
Antiphospholipid antibody syndrome
Multiple gestation
Family or personal history of preeclampsia
Age > 40 years
African-American race
Diabetes mellitus
10. DISEASE OF THEORIES
Etiology is unknown.
Many theories:
Abnormal Placentation
Endothelial cell dysfunction
Imbalance b/w TXA2 & PGI2
dietary deficiency (calcium, magnesium, zinc)
▪ supplementation has not proven effective
11. A major underlying defect is a relative deficiency
of prostacyclin vs. thromboxane
Normally (non-preeclamptic) there is an 8-10 fold
↑ in prostacyclin with a smaller ↑ in thromboxane
prostacyclin salutatory effects dominate
▪ vasodilation, ↓ platelet aggregation, ↓ uterine tone
In preeclampsia, thromboxane’s effects dominate
↑ thromboxane (from platelets, placenta)
↓ prostacyclin (from endothelium, placenta)
12. Aspirin has been extensively studied as a targeted
therapy to ↓ thromboxane production
CLASP study, 1994, multicenter, randomized
CLASP Collaborative Group, Lancet 1994;343:619-29
9364 women, risk factors for PIH or IUGR or who had PIH
or IUGR
60 mg ASA daily vs. placebo
Small reduction (12%) in occurrence of PIH
Small reduction in preterm deliveries: 20 vs 22%
No difference in neonatal outcome
13. NIH study of high-risk patients, randomized, 60 mg
aspirin daily vs. placebo
Caritis, et al., N Engl J Med 1998;338:701-5
pre-gestational DM (471 patients)
chronic hypertension (774 patients)
multifetal gestations (688 patients)
prior history of preeclampsia (606 patients)
No reduction in development of preeclampsia in any
subgroup or groups in aggregate
No difference in perinatal death, preterm delivery,
IUGR, maternal or fetal hemorrhagic complications
14. At this time the most widely accepted proposed
mechanism for preeclampsia is:
▪ global endothelial cell dysfunction
Redman: endothelial cell dysfunction is just one
manifestation of a broader intravascular
inflammatory response
Redman, et al., Am J Obstet Gynecol 1999;180:499-506
present in normal pregnancy
excessive in preeclampsia
Proposed source of inflammatory stimulus: placenta
15. In severe preeclampsia, typically hyperdynamic
with normal-high CO, normal-mod. high SVR,
and normal PCWP and CVP.
Despite normal filling pressures, intravascular
fluid volume is reduced (30-40% in severe PIH)
Variations in presentation depending on prior
treatment and severity and duration of disease
Total body water is increased (generalized
edema)
16. Preeclamptic patients are prone to develop
pulmonary edema due to reduced colloid oncotic
pressure (COP), which falls further postpartum:
Colloid oncotic pressure:
Antepartum
Postpartum
Normal pregnancy: 22 mm Hg 17 mm Hg
Preeclampsia: 18 mm Hg 14 mm Hg
17. Respiratory:
Airway is edematous; use smaller ET tube (6.5)
↑ risk of pulmonary edema; 70% postpartum
Renal:
Renal blood flow & GFR are decreased
Renal failure due to ↓ plasma volume or renal artery
vasospasm
Proteinuria due to glomerulopathy
▪ glomerular capillary endothelial swelling w/subendothelial
protein deposits
Renal function recovers quickly postpartum
18. RUQ pain is a serious complaint
warrants imaging, especially when accompanied
by ↑ liver enzymes
caused by liver swelling, periportal hemorrhage,
subcapsular hematoma, hepatic rupture (30%
mortality)
HELLP syndrome occurs in ~ 20% of severe
preeclamptics.
19. Coagulation:
Generally hypercoagulable with evidence of platelet
activation and increased fibrinolysis
Thrombocytopenia is common, but fewer than 10%
have platelet count < 100,000
DIC may occur, esp. with placental abruption
Neurologic:
Symptoms: headache, visual changes, seizures
Hyperreflexia is usually present
Eclamptic seizures may occur even w/out ↑↑BP
▪ Possible causes: hypertensive encephalopathy, cerebral
edema, thrombosis, hemorrhage, vasospasm
20. Hemolysis – abnormal peripheral smear
Increased bilirubin level
Elevated liver enzymes- SGOT>70U/L
LDH>600U/L
Low platelet count<100000/mm3
Clinical features –Malaise(90%) , Epigastric pain(90%),
Nausea & vomitting(50%), Flu like syndrome
Usually before 36 weeks
70% antepartum & 30% postpartum
Rapidly progress to DIC
Associated with high maternal & fetal mortality
21. LIKE A FLASH OF LIGHTENING
Preeclampsia complicated by convulsion /coma
Most common in primi & multiple pregnancy
Cause of convulsion
Hypertensive encephalopathy
Vasospasm- ischemia
Infarction
Haemorrhage
Oedema
23. Differential Diagnosis
Epilepsy,ICSOL,Meningitis,Hysteria
Management
MgSO4 is the DOC for seizure control & prevention of recurrent
eclamptic seizures
Reduces seizures by >50%
4g MgSO4 iv over 10 min followed by a maintanence infusion of 1g/hr
Mg also causes vasodilataion & increase in CO by reducing SVR
Narrow Therapeutic Index ,with serum Mg level b/w 2 & 3.5 mmol/L .
Therapeutic level 4-6 mEq/L
If toxicity present 10 ml 10 % Ca gluconate given slow iv
27. Classically “stabilize and deliver”
Medical management while awaiting delivery:
use of steroids X 48 hours if fetus < 34 wks
antihypertensives to maintain DBP < 105-110
magnesium sulfate for seizure prophylaxis
monitor fluid balance, I/O, daily weights, symptoms, reflexes,
HCT, plts, LFT’s, proteinuria
Indications for expedited delivery:
fetal distress
↑ BP despite aggressive Rx
worsening end-organ function
development or worsening of HELLP syndrome
development of eclampsia
28. Most commonly, for acute control:
1.)Hydralazine
Arterial dilator, dose 5-10mg iv ,slow onset 20-30mtsDOA: 2-3 hrs
2) Labetolol
10-20mg iv, Improves placental blood flow ,Rapid onset of action 1-2mts
DOA-2-3hrs
CI- Bronchial asthma,CCF
Most common for chronic control:
Alpha methyl dopa.
Central alpha 2 agonist
Dose – 250 mg bd
DOC for chronic treatment
29. Nifedipine may be used, but unexpected hypotension may
occur when given with MgSO4
For refractory hypertension: nitroglycerin or nitroprusside may
be used
Nitroprusside dose and duration should be limited to avoid
fetal cyanide toxicity
Usually require invasive arterial pressure monitoring
Angiotensin-converting enzyme (ACE) inhibitors
contraindicated due to severe adverse fetal effects
30. Evidence is strong that magnesium sulfate is
indicated for
seizure treatment in eclamptics
seizure prophylaxis in severe preeclamptics
Role of magnesium prophylaxis in mild
preeclamptics is less clear
awaits large, prospective, randomized, placebo-
controlled trial
31. Magnesium sulfate has many effects; its
mechanism in seizure control is not clear.
NMDA (N-methyl-D-aspartate) antagonist
vasodilator
▪ Brain parenchymal vasodilation demonstrated in
preeclamptics by Doppler ultrasonography
increases release of prostacyclin
Potential adverse effects:
toxicity from overdose (respiratory, cardiac)
↑ bleeding
↑ hypotension with hemorrhage
↓ uterine contractility
32. Renally excreted
Preeclamptics prone to renal failure
Magnesium levels must be monitored frequently
either clinically (patellar reflexes) or by checking
serum levels q 6-8 hours
▪ Therapeutic level: 4-7 meq/L
▪ Patellar reflexes lost: 8-10 meq/L
▪ Respiratory depression: 10-15 meq/L
▪ Respiratory paralysis: 12-15 meq/L
▪ Cardiac arrest: 25-30 meq/L
Treatment of magnesium toxicity:
stop MgSO4, IV calcium, manage airway
33. Seizures are usually short-lived.
If necessary, small doses of barbiturate or
benzodiazepine (STP, 50 mg, or midazolam, 1-2
mg) and supplemental oxygen by mask.
If seizure persists or patient is not breathing, rapid
sequence induction with cricoid pressure and
intubation should be performed.
Patient may be extubated once she is completely
awake, recovered from neuromuscular blockade,
and magnesium sulfate has been administered.
35. To establish & maintain hemodynamic
stability (control hypertension & avoid
hypotension)
To provide excellent labor analgesia
To prevent complications of preeclampsia
To be able to rapidly provide anesthesia for
C/S
To avoid drug induced depression
36. Newer studies shows that degree of hypotension in spinal & epidural
block is same in PIH pt
So we can use either spinal / epidural
Graded epidural in a preeclampsia patient
5ml (0.5% bupivacaine)loading dose to attain T10 level
Then 5 ml increment at 5 mt interval to attain T4 level
Fentanyl(50-100mcg) can be added to increase speed of onset , duration
quality
Advantages of epidural
Gradual onset of sympathetic blockade
Cardiovascular stability
Avoids neonatal depression
37. Hood, et al., Anesthesiology 1999;90:1276-82
Retrospective study
Lowest intraoperative blood pressures not different
Total ephedrine use was small & not different
Spinal group received 400 cc more IV fluid
No pulmonary edema attributable to intraop fluid
Maternal & infant outcomes were similar
38. Prior to placing regional block in a preeclamptic it
is recommended to check the platelet count.
No concrete evidence at to the lowest safe platelet
count for regional anesthesia in preeclampsia
Any clinical evidence of DIC would contraindicate
regional
In the absence of such signs, most
anesthesiologists would proceed at plt count
>100000, many would proceed at 80000-100000,
<80000 some would proceed (esp. spinal)
39. When placing a regional block in a patient with a
platelet count < 100000, the most important thing
is to monitor resolution of block closely
Bleeding time has been discredited as an indicator
of epidural bleeding risk and is not indicated.
Channing-Rogers, Semin Thromb Hemost 1990;16:;1-30
Low-dose aspirin is not a contraindication to
regional anesthesia in preeclampsia
CLASP study: 1422 women on aspirin received epidurals
without any bleeding complications
40. Epidural anesthesia would probably be preferred
by many anesthesiologists in a severely
preeclamptic pt in a non-urgent setting
For urgent cases it is reassuring to know that
spinal is also safe
This allows us to avoid general anesthesia with
the potential for encountering a swollen, difficult
airway and/or labile hypertension
41. General anesthesia is a well-known hazard in
obstetric anesthesia:
16X more likely to result in anesthetic-related
maternal mortality
Mostly due to airway/respiratory complications,
which would only be exaggerated in preeclampsia
Hawkins, Anesthesiology 1997;86:273
42. Airway edema is common
Mandatory to reexamine the airway soon before
induction
Edema may appear or worsen at any time during the
course of disease
▪ tongue & facial, as well as laryngeal
Laryngoscopy and intubation may → severe ↑BP
Labetolol & NTG are commonly used acutely
Fentanyl (2.5 mcg/kg), alfentanil (10 mcg/kg), lidocaine
may be given to blunt response
43. Magnesium sulfate potentiates depolarizing
& non-depolarizing muscle relaxants
Pre-curarization is not indicated.
Initial dose of succinylcholine is not reduced.
Neuromuscular blockade should be monitored &
reversal confirmed.
44. Usually reserved for patients with
complications
oliguria unresponsive to modest fluid challenge (500
cc LR X 2)
pulmonary edema
refractory hypertension
▪ may have increased CO or increased SVR
Poor correlation between CVP and PCWP in PIH
However, at most centers anesthesiologists would
begin with CVP & follow trend
▪ not arbitrarily hydrate to a certain number
45. Preeclampsia is a serious multi-organ system
disorder of pregnancy that continues to defy our
complete understanding.
It is characterized by global endothelial cell
dysfunction.
The cause remains unknown.
There is no effective prophylaxis.
46. Delivery is the only effective cure.
Magnesium sulfate is now proven as the best
medication to prevent and treat eclampsia.
Epidural analgesia for labor pain
management & regional anesthesia for C/S
have many beneficial effects & are preferred.