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)

CCC 700 6

Critical Care

Compendium

One comment

  1. Hi Chris, just wondering about the loading dose of MgSO4. Dunn mentions a loading dose of 4g over 10 min for eclampsia and over 20 min in pre eclampsia. Other sources also mention a loading dose of 4-6 g over 20 min.
    Will giving it over 5 min cause any harm?

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