Pre-eclampsia and Eclampsia

DEFINITIONS

• multisystem disorder of pregnancy characterised by hypertension and organ system derangement.
• defective trophoblast invasion of the spiral arteries and abnormal trophoblast differentiation.

Pre-eclampsia – hypertension occurring after 20 weeks gestation and resolving within 3 months of delivery with the following specific features:

• SBP > 140mmHg or DBP > 90mmHg

+ one or more of

• proteinuria (>0.3g/24hrs)
• renal impairment – proteinuria, high Cr
• liver disease – epigastric pain, liver tenderness, elevated transaminases
• neurological problems – seizures, visual disturbance, papilloedema, clonus
• haematological disturbance – thrombocytopaenia, haemolysis, DIC
• fetal growth restriction – non reassuring CTG, reverse flow on Doppler, IUGR
• severe if SBP >160 or DBP >110 or severe organ dysfunction

Gestational Hypertension – occurs during pregnancy but not associated with other signs of PET

Pre-existing Hypertension – HT that existed before pregnancy

Eclampsia – a seizure in a patient with PET

HISTORY

• asymptomatic
• headaches
• RUQ pain
• cortical blindness
• transient scotomata
• SOB

RISK FACTORS

• PET during another pregnancy
• advanced maternal age
• multiple pregnancy
• high BMI
• conception before age 20
• connective tissue disorders
• protein C and S deficiencies
• factor V leiden mutation
• hyperhomocysteinemia

EXAMINATION

• BP >140/90
• hyperreflexic
• agitated
• epigastric or RUQ pain
• pulmonary oedema
• oliguria

INVESTIGATIONS

• proteinuria > 2g in 24 hrs
• elevated creatinine
• transaminitis
• elevated bilirubin
• thrombocytopaenia
• deranged coagulation
• haemolysis
• high urate
• hypocalaemia
• PT and APTT normal (unless has abruption or severe hepatic involvement)

MANAGEMENT

Aims

1. management of HT
2. delivery of baby and placenta
3. prevention of eclampsia

• position patient in left lateral tilt
• intermittent -> continuous monitoring of baby
• MDT input (obstetrician, neonatologist, midwife)
• reduce BP to <140/90 – aggressively treat if >160/110 (decrease by 10-20mmHg every 20min)
• antihypertensives;
  1. methyldopa PO 0.5-3g/day
  2. labetalol IV 5-10mg injected slowly
  3. nifedipine PO 10-20mg or IV 100-200mg over 2 min
  4. beta-blockers (metoprolol, pindolol, propanolol, esmolol)
  5. hydralazine IV 10-20mg slowly
  6. GTN IV 0.1-0.8mcg/kg/min
  7. SNP IV 1-4mcg/kg/min

• load with MgSO4 (5g over 5min -> 1g/hr, monitor for toxicity – drowsiness, loss of patella reflexes, respiratory depression, loss of consciousness -> treatment = stop infusion and 10mL calcium gluconate 10%)
• cautious IV fluids (high risk of APO)
• platelet count needs coagulation screen
• epidurals good if no contraindications
• if decision to move to C/S standard care

Intraoperative/labour Management

• single shot spinal, CSE and epidural have all been employed
• hypotension less common
• GA; abate hypertensive response to intubation (1mg alfentanil), monitor for APO @ emergence
• use arterial line
• avoid syntometrine and ergometrine -> acute hypertension

Postoperative/delivery Management

• continue antihypertensives
• continue MgSO4
• NSAIDs if not contraindicated
• thromboprophylaxis
• manage APO in standard manner (LMNOP)