Preeclampsia and Eclampsia: A Case-Based Discussion

Case Presentation and Diagnosis
What is the preliminary diagnosis of this case?
The preliminary diagnosis is a 31-year-old primigravida at 38 weeks of gestation, a case of hypertensive disorder of pregnancy (preeclampsia) with a single live intrauterine pregnancy in cephalic presentation.
She is admitted for safe confinement and falls under ASA PS2.

How are hypertensive disorders of pregnancy classified?
Hypertensive disorders of pregnancy are classified into those occurring at less than 20 weeks and those at more than or equal to 20 weeks.
Can you define the different hypertensive disorders?
  • Gestational hypertension: BP more than or equal to 140/90 after 20 weeks of gestation, which becomes normal within 12 weeks postpartum.
  • Preeclampsia: Gestational hypertension with proteinuria, or with or without proteinuria and one of the features of end-organ damage.
  • Eclampsia: Preeclampsia with new-onset seizures and/or coma.
  • Chronic hypertension: Pre-existing hypertension that persists after 12 weeks postpartum.
  • Chronic hypertension superimposed with preeclampsia: Chronic hypertension with new-onset proteinuria and worsening hypertension.

How is preeclampsia further divided based on severity?
Preeclampsia can be divided into:
  • Without severe features (mild preeclampsia): BP more than or equal to 140/90 on two occasions 4 hours apart after 20 weeks of gestation in a previously normotensive patient, with proteinuria (more than or equal to 300 mg per 24-hour urine collection, urine protein/creatinine ratio more than or equal to 0.3, or urine dipstick 2+).
  • With severe features: BP more than or equal to 160/110, with or without proteinuria, and one or more of the following:
    • Platelet count less than 100,000/µL
    • Renal insufficiency (serum creatinine more than 1.1 mg/dL)
    • Impaired liver function
    • Severe epigastric or right upper quadrant pain (HELLP syndrome)
    • Pulmonary edema
    • New-onset headache, blurring of vision, or altered mental status
    Proteinuria in severe features can be more than 5 grams.

What is HELLP syndrome?
HELLP syndrome is a form of preeclampsia with severe features characterized by Hemolysis, Elevated Liver enzymes, and Low Platelet count.

What are the risk factors for preeclampsia that should be asked for in the history?
Risk factors can be categorized into:
  • Maternal factors: Primigravida, elderly primigravida, history of chronic hypertension, diabetes or GDM, CKD, obesity, and family history of preeclampsia or prior history of preeclampsia in pregnancies.
  • Pregnancy-related factors: Multiple gestation, history of molar pregnancy, erythroblastosis fetalis, and abruption placenta.
  • Partner-related factors: History of limited sperm exposure.


Pathophysiology of Preeclampsia
Can you explain the etiopathogenesis of preeclampsia?
In normal pregnancy, complete trophoblastic invasion leads to remodeling of the spiral arteries, increasing blood flow to the placental unit. In preeclampsia, there is incomplete trophoblastic invasion.
This results in high-resistance vessels, causing decreased blood flow and placental hypoxia. This leads to an increased release of anti-angiogenic factors, endothelial cell damage, and end-organ damage.
This process causes multi-organ dysfunction like proteinuria, brain edema, and coagulation abnormalities. There is increased production of and sensitivity to vasoconstrictors (thromboxane A2, angiotensin 2, serotonin, endothelin) and decreased production of and sensitivity to vasodilators (nitric oxide, prostacyclin). The end result is vasospasm and the triad of vasospasm, plasma volume contraction, and DIC.

What are the pathophysiological changes that occur due to this condition?
  • Airway: Edema, leading to difficult airway management.
  • Respiratory: Pulmonary edema, greater ventilation-perfusion mismatch.
  • Hepatic: Abnormal LFTs, subcapsular hemorrhage, HELLP syndrome.
  • Fetal: Growth restriction due to placental insufficiency, pre-term delivery, abruption.
  • CNS: Headache, visual disturbances, eclampsia, coma.
  • Cardiovascular: Increased sensitivity to vasoconstrictors, increased systemic vascular resistance, plasma volume contraction.
  • Renal: Proteinuria, decreased glomerular filtration rate, which might cause renal failure.
  • Hematological: Thrombocytopenia, increased clotting factors, risk of DIC.
In essence, there is extensive uteroplacental and systemic vasospasm with a contracted blood volume, leading to end-organ damage.

What are the salient differences between physiological changes in normal pregnancy and those in hypertensive disorders of pregnancy?
  • Cardiovascular: In normal pregnancy, cardiac output increases and systemic vascular resistance decreases, with BP decreasing in mid-pregnancy. In preeclampsia, SVR increases, cardiac output is abnormal or decreased, and BP is elevated.
  • Renal: Normal pregnancy sees increased renal blood flow and GFR. Preeclampsia involves decreased GFR and proteinuria.
  • Hematology: Normal pregnancy has mild anemia and increased clotting tendency. Preeclampsia presents with thrombocytopenia and a risk of DIC.
  • Placental perfusion: Adequate spiral artery remodeling occurs normally, while preeclampsia shows poor trophoblastic invasion and decreased placental perfusion.
  • Endothelial function: Normal vasodilation response is seen in normal pregnancy, whereas preeclampsia involves endothelial dysfunction and increased vasoconstrictor sensitivity.
  • Hepatic system: Typically normal in pregnancy, but preeclampsia can show elevated LFTs and risk of HELLP syndrome.
  • Respiratory system: Increased tidal volume and mild respiratory alkalosis in normal pregnancy. Severe preeclampsia carries a risk of pulmonary edema.


Investigations and Preoperative Management
What specific investigations will you do and for what reason?
Over and above routine investigations (including blood grouping and cross-matching), specific tests are done to rule out end-organ damage and severe preeclampsia:
  • Urine protein: To confirm and quantify proteinuria.
  • Renal function tests (RFT): To assess for renal insufficiency.
  • Liver function tests (LFT): To detect liver involvement and HELLP syndrome.
  • Peripheral smear, platelet count, and coagulation profile: To rule out thrombocytopenia, coagulopathy, and DIC.

What are the common antihypertensive drugs used, and what are their anesthetic implications?
  • Oral Labetalol: A non-selective alpha and beta-blocker. It can cause hypoglycemia and is usually avoided in patients with asthma, heart failure, or heart block. It might cause bradycardia.
  • Oral Nifedipine: A calcium channel blocker. A common side effect is overshoot hypotension. It can be given at 10 mg every 20 minutes in a hypertensive crisis.
  • IV Labetalol: Used in hypertensive crisis. Side effects include neonatal bradycardia and hypoglycemia.
  • Methyldopa: An alpha-2 agonist. Its onset is 12-24 hours. Main side effects are dry mouth, sedation, and depression.

What is the role of magnesium sulfate therapy in preeclampsia/eclampsia?
Magnesium sulfate therapy is initiated for seizure prophylaxis and treatment in patients with severe preeclampsia with severe features, warning signs of impending eclampsia, or a history of eclamptic seizures.
What are the different regimens for magnesium sulfate administration?
  • Pritchard's regimen (IM): A loading dose of 10 grams IM, followed by a maintenance dose of 5 grams IM every 4 hours.
  • Zuspan's regimen (IV): A loading dose of 6 grams IV over 15-20 minutes, followed by a maintenance dose of 2 grams IV per hour.
During therapy, it is crucial to monitor urine output, knee-jerk reflex, and respiratory rate.

Is there any role for corticosteroid therapy in preeclampsia?
Yes, corticosteroids have a role. Dexamethasone may help improve platelet count in HELLP syndrome. Betamethasone is used for promoting fetal lung maturity.

What are the different ways a preeclamptic patient can present to an anesthesiologist?
  • For labor analgesia.
  • For an elective cesarean section.
  • As an emergency (e.g., for emergency delivery).
  • With seizures in the labor room.
  • In a cardiac arrest situation.

How would you counsel a preeclamptic patient for labor analgesia?
Counseling should be done in a calm, quiet environment with the patient's husband present. After a proper introduction and building rapport, the options for labor analgesia should be explained, along with their advantages and disadvantages, allowing the patient to make an informed choice. Counseling should also include information about CNS features and other complications.

What preoperative advice and preparation would you give for a planned procedure?
  • Ensure hypertension is well-controlled and seizure prophylaxis is initiated.
  • Optimize volume status.
  • Perform a complete physical examination, including a thorough airway evaluation, and prepare equipment for a difficult airway.
  • Confirm NPO status and administer aspiration prophylaxis.
  • Secure two large-bore IV lines and ensure blood and blood products are cross-matched.
  • Consider an arterial line for beat-to-beat BP monitoring in acute hypertensive crisis or if potent vasodilators are used.
  • Review lab investigations: CBC, platelet count, LFT, serum creatinine, blood urea, urine analysis, PT/INR, aPTT, and fibrinogen levels.


Anesthetic Management for Labor and Delivery
What drugs are commonly used for epidural analgesia in labor?
  • Local anesthetics: Bupivacaine (0.0625% to 0.125%), ropivacaine, levobupivacaine, or lignocaine.
  • Adjuvants: Fentanyl or sufentanil for epidural and spinal analgesia. Morphine and meperidine can be given for spinal analgesia.

How would you initiate and maintain epidural analgesia for a preeclamptic patient in labor?
After placing the epidural catheter at the L1-L2 or L2-L3 level, an initial dose of 10 ml of 0.125% bupivacaine mixed with fentanyl can be given. Alternatively, 2% plain lignocaine can be used as a test dose. Analgesia can be maintained with an epidural infusion of the same bupivacaine-fentanyl mixture at 10 to 12 ml per hour.

How do you identify the epidural space in a pregnant patient?
In pregnancy, due to lumbar lordosis and engorgement of epidural veins, the epidural space pressure may increase. Therefore, the loss of resistance technique is preferred over the hanging drop method.

What dermatomes need to be blocked for labor analgesia?
  • First stage of labor: Dermatomes T10 to L1.
  • Second stage of labor: Dermatomes S2, S3, S4.
The epidural catheter is usually placed at L1-L2 or L2-L3 to achieve a block from T10 to S4.

What precautions should be taken when giving a top-up dose through an epidural catheter?
A test dose should always be administered to rule out intravascular or intrathecal displacement of the catheter. Adrenaline-containing test doses should be avoided in preeclamptic patients.

How would you manage a patient with a patchy epidural who develops fetal distress and is rushed for an emergency cesarean section?
If the epidural is patchy and inadequate for surgery, general anesthesia is indicated.
  1. Administer 100% oxygen to alleviate fetal distress.
  2. Administer aspiration prophylaxis.
  3. Prepare for a difficult airway.
  4. Proceed with rapid sequence induction.
Postoperative analgesia can be managed with NSAIDs, paracetamol, or other systemic opioids.

What are the specific concerns with general anesthesia in a preeclamptic patient?
  • Exaggerated hypertensive response to laryngoscopy.
  • Potential for raised ICP.
  • Airway edema, making intubation difficult.
  • Risk of bleeding from thrombocytopenia or coagulopathy.
  • Plasma volume contraction, leading to hemodynamic instability.
  • High risk of pulmonary edema.
  • End-organ dysfunction.
  • Drug interactions, e.g., magnesium sulfate potentiating muscle relaxants.

What is the postoperative analgesia plan for this patient?
  • If the epidural catheter is working well, 0.2% ropivacaine can be used as an epidural infusion for up to 72 hours.
  • Oral paracetamol 1 g 6-8 hourly, starting 6-8 hours after the intraoperative dose.
  • Oral ibuprofen 400-600 mg 6 hourly, unless contraindicated, starting 6-8 hours after the intraoperative dose.
  • Patient-controlled epidural analgesia (PCEA) with or without a rescue block (e.g., TAP block) can be given.
  • If long-acting neuraxial opioids are used, monitor respiratory rate and sedation 2-hourly for 12 hours.


Management of Acute Complications
What are the differential diagnoses if a patient throws a seizure during a top-up?
  • Eclampsia
  • Local Anesthetic Systemic Toxicity (LAST)
  • Hypoglycemia
  • Electrolyte imbalance

How would you manage a patient who has a seizure?
  1. Follow ABC: Secure the airway, ensure proper positioning, and administer 100% oxygen.
  2. Protect the patient from injury (e.g., tongue bite, padding).
  3. If due to eclampsia, magnesium sulfate is first-line.
  4. For seizure control, drugs like lorazepam, phenytoin, or thiopentone can be used if available.

How would you manage a patient who goes into cardiac arrest?
  1. Initiate high-quality CPR and follow ACLS protocol (defibrillation if indicated, adrenaline).
  2. Assemble the maternal cardiac arrest team immediately.
  3. Consider the etiology of the arrest.
  4. Perform airway management with 100% oxygen, avoiding excessive ventilation.
  5. Place an IV line above the level of the diaphragm.
  6. If the patient is receiving IV magnesium, stop it and give calcium gluconate or calcium chloride.
  7. Provide left lateral displacement of the uterus.
  8. Detach all fetal monitors.
  9. Prepare for a perimortem cesarean delivery if there is no ROSC within 5 minutes.


Regional vs. General Anesthesia
In a stable preeclamptic patient without coagulopathy, which anesthetic technique is preferred and why?
Regional anesthesia (epidural or spinal) is preferred.
What are the advantages of regional anesthesia in this context?
  • Avoids airway instrumentation and the associated stress response.
  • Provides excellent postoperative analgesia if an epidural catheter is used.
  • Allows for early ambulation.
  • Blunts the sympathetic response to pain, which can help control BP.
  • Avoids the potential complications of GA specific to preeclampsia (hypertensive response to laryngoscopy, difficult airway, drug interactions).
The main concern with regional anesthesia is ruling out coagulopathy, but with a normal platelet count, it is safe.