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Pre-Eclampsia and Related Disorders. Critical Care Fellow Teaching Feb 2017. Learning Outcomes. Spectrum of disorders Pathogenesis Presentation Reasons to admit to ICU Treatment Hypertension Seizures Fluid balance. Spectrum of Disorders. Pre-eclampsia
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Pre-Eclampsia and Related Disorders Critical Care Fellow Teaching Feb 2017
Learning Outcomes • Spectrum of disorders • Pathogenesis • Presentation • Reasons to admit to ICU • Treatment • Hypertension • Seizures • Fluid balance
Spectrum of Disorders • Pre-eclampsia • Pregnancy induced hypertension with proteinuria • Severe pre-eclampsia • Eclampsia • HELLP syndrome • Haemolysis, elevated liver enzymes and low platelets
Preeclampsia • >20/40 gestation • New onset hypertension • SBP >140 +/or • DBP >90 • New onset proteinuria • ≥300mg protein per 24hrs • 2-7% pregnancies • 1.5 maternal deaths per 100,000 deliveries
Severe Preeclampsia • CVS/Respiratory • SBP >160 +/or DBP >110 • Pulmonary oedema • Cyanosis • Neurological • Persistent headaches • Visual disturbances • SAH • Raised ICP • Stroke • Renal • Proteinuria ≥2g / 24hrs • PCR >0.2g/mmol • Oliguria <500ml / 24hrs • Creatinine >80 • Hepatic • RUQ or epigastric pain • Raised bilirubin or transaminases • Haematological • Thrombocytopenia • Abnormal clotting studies • Haemolysis
Eclampsia • Seizures • Can occur without hypertension or proteinuria • At least 1/3rd occur post delivery • Do still occur >48 hrs post delivery • 0.04-0.1% pregnancies • 1.8% maternal mortality • 7% fetal / neonatal mortality
HELLP Syndrome • Severe sub-set of preeclampsia • Predominately hepatic dysfunction (rather than renal and cerebral) • In contrast to preeclampsia pts (Afro-Caribbean and primip’s) are usually white and multip’s • Haemolysis • Elevated Liver enzymes • Low Platelets
HELLP Syndrome • RUQ +/or epigastric pain • Nausea • Malaise • Hypertension and proteinuria (usually) • 30% present post partum – may have had no signs of preeclampsia before • Post delivery – get worse for 24-48hrs then gradually improve
Severe Complications of HELLP • Severe ascites • Liver haemorrhage • Liver rupture • Liver failure • DIC • Abruption • AKI • Pulmonary oedema • ARDS • Sepsis • Stroke
Pathogenesis • Cause(s) not fully understood • Immunological • Genetic (2p, 12q, ?13) • Failure of normal placentation • Endothelial dysfunction • Inflammatory response • Fatty acid metabolism • Coagulation and platelet dysfunction
Maternal Risk Factors • <20 or >35 years old • Obesity • Past or family history (4x risk) • Short (<155cm tall) • Pre-existing hypertension • Past history of migraine or renal disease • SLE, antiphospholipid syndrome • Afro-Caribbean origin • Diabetes • Lack of “sperm-mediated partner-specific immune tolerance” • Lower incidence in smokers
Fetal Risk Factors • Increased placental mass • Multiple pregnancy (IVF) • Placental hydrops • Molar pregnancy • Genetic factors • Trisomy 13
Clinical Features – CVS/Respiratory • Increased SVR – hypertension • Not sympathetically mediated • Very sensitive to vasopressors • Reduced IV volume • Reduced cardiac output • Due to reduced preload and increased afterload (contractility usually ok) • Pulmonary oedema • Leaky capillaries, LV dysfunction, reduced colloid oncotic pressure of pulmonary capillaries • Iatrogenic • Laryngeal oedema
Clinical Features - CNS • Cerebral oedema • Raised ICP • Intracranial haemorrhage • Seizures • Cerebral oedema and vasospasm (endothelial dysfunction) • Breakdown of blood brain barrier
Clinical Features - Renal • Reduced renal plasma flow and GFR • Glomeruloendotheliosis • Hyperuricaemia • Reduced clearance • Associated with maternal and fetal morbidity and mortality • Rises early in disease • Urine protein/creatinine ratio
Clinical Features - Haematological • Thrombocytopenia – DIC • Reduced platelet function
Clinical Features - Hepatic • Liver oedema • Hepatocellular necrosis • Hepatic infarcts • Haemorrhage – periportal and subcapsular • Rupture • More common in those with HELLP
Why admit to ICU? • Cardiorespiratory failure • Intracranial haemorrhage • Uncontrollable seizures • Renal and hepatic failure • DIC
General Management of a Sick Pregnant Woman • Avoid aorto-caval compression • H2 antagonists • Steroids for fetal lung maturation • Early warning score obs – regularly • Serial bloods and urine testing • CTG
Specific Management • Delivery of the placenta (and fetus) • Pre-delivery • Control BP • Prevent seizures • Maintain placental perfusion • Prevent complications • Try to avoid premature delivery – major cause of neonatal morbidity and mortality • Post-delivery – largely supportive
Delivery • Normal vaginal delivery • Caesarean section • Platelet count • Clotting • Try to avoid GA
Hypertension Management • Indicated to prevent stroke, cardiac failure and abruption • SBP >160 +/or DBP >105-110 • Must monitor fetus during treatment • May require cautious IV fluid during treatment as sudden hypotension is possible
Pharmacological Management of Hypertension • Hydralazine (IV) – intermittent boluses • Headache, tachycardia, tremor and nausea • Labetalol (IV) – bolus and infusion • Does cross placenta but fetal problems rare • Avoid in asthma and cardiac failure • Nifedipine (oral) • Relaxes uterine smooth muscle – bleeding • Sodium Nitroprusside • Only in hypertensive crisis • GTN (or equivalent) • Good in pulmonary oedema
Seizures • Vasospasm and cerebral oedema induced • Warning signs and symptoms include • Visual disturbances, hyper-reflexia, headache • Eclamptic fits are usually short lived and self terminating – can be prolonged • 1/3rd of eclamptic fits occur post partum – can be >48hrs post delivery
Seizure Differential Diagnosis • Eclampsia • Epilepsy • Embolism • Clot, air, amniotic fluid • Intra-cerebral pathology • Bleed, thrombus, tumour • LA toxicity • Hyponatraemia
Seizure Prophylaxis • Magnesium for 24-48hrs post delivery • Mode of action not totally clear • Calcium antagonism and vasodilatation • BP • Renal and uterine blood flow • Blockade / suppression of NMDA receptors
Problems with Magnesium • Does needs to be reduced in renal disease • Toxicity • Reference 0.7-1.2 mmol/l • Target 2-3 • Loss of deep tendon reflexes (check upper limb) 3.5-5 • Resp depression >5 • Cardiac arrest >12.5 • Increased PR, QT and QRS at any level over reference range • Tocolytic – slows cervical dilatation • Potentates muscle relaxants • Increased risk of pulmonary oedema • Does cross placenta – floppy baby with resp depression
Seizure Treatment • ABC • Magnesium • Diazepam if prolonged • Thiopentone, suxamethonium, opiate, intubate if required • Consider CT head • Standard neuro-critical care management to keep ICP down and CPP up
Neuro-Critical Care Management • Treat cause • Bleed • Cerebral oedema • Venous thrombosis • Sedate • 30° head up • PaCO2 4.5-5 kPa • MAP to keep CPP 60-70 mmHg • Don’t obstruct venous drainage • 2 patients – monitor both and liaise with obstetricians – deliver baby when safe to do so
Seizure Summary • Identify those at risk – where possible • Prevent – magnesium • Don’t forget differential diagnosis
Fluid Balance • Difficult – reduced IV volume and frequently oliguric but high risk of pulmonary oedema • Aggressive fluid loading not encouraged • Maintenance of 75-125ml/hr – all routes • Boluses 250ml crystalloid • CVP for trends – clotting, abnormal ECG • Accept oliguria
Pulmonary Oedema • Risk is highest post-delivery – most deaths post partum • Oxygen • Positive pressure ventilation • Invasive or non-invasive • Inotropes • Vasodilators • Diuretics
Acute Kidney Injury • Thankfully rare • All patients should have regular creatinine measurements • May require filtration • High chance of full recovery
Liver Injury • Supportive • Rupture is a surgical emergency • Otherwise – avoid making it worse
Summary • The preeclampsia spectrum are common diagnoses – do not fit into neat categories • Many serious problems occur post delivery • Relapses post delivery do occur – continue monitoring and treating • Managed correctly – good outcome • Full return of normal organ function 6 weeks • Treatment is largely supportive