– Medical emergencies in pregnancy






15.1

Medical problems in pregnancy



  • About: the call to the obstetric unit for medical issues can be intimidating to even the most accomplished doctor. This is a collection of a few basic facts and principles to help you. As ever, if unsure of what you are doing then get help. This is to deal mainly with acute and on-call questions. Pregnancy is covered within resuscitation, asthma and DVT/pulmonary embolism and headache sections.
  • General principles: most women in pregnancy are healthy. Those with known or anticipated medical disorders require expert care which is really the preserve of the obstetric team liaising with medical specialists as needed. Communication is key. Medical disorders can be considered in terms of disorders caused by the pregnancy and pre-existing disorders exacerbated by the effects of the pregnancy, e.g. heart disease, asthma, immune disorders, clotting disorders, epilepsy. It is important to involve senior members of the obstetric team when making any significant management plans that can affect the pregnancy.








Medical advice on managing pregnant patients



  • There are two (or sometimes more) patients.
  • Give folate prior to conception and in the first trimester.
  • Tachypnoea or ↑HR must not be ignored.
  • A pink Venflon is useless in a sick pregnant patient.
  • Ectopic pregnancy can be atypical, e.g. ‘fainting, D&V‘.
  • ALP (placental) rises in 3rd trimester.
  • CXR: safe (3 days background radiation) but shield fetus.
  • Avoid prescribing in 1st trimester unless proven safety.

  • Avoid NSAIDs, ACEIs, ARBs, trimethoprim, warfarin.
  • For anticoagulation use LMWH or IV heparin.
  • Consider diagnosing PE by diagnosing a DVT first.
  • For hyperemesis don’t forget thiamine (give Pabrinex).
  • You can use salbutamol, steroids and magnesium for asthma.
  • Magnesium for preventing eclamptic seizures.
  • Accidental magnesium overdose can be fatal. Give IV calcium gluconate.
  • Maximum cardiac at 14 weeks and just following delivery.






15.2

Pharmacology in pregnancy


Sources of prescribing advice in UK



  • BNF or your local equivalent. National Teratology Information Service (NTIS) in Newcastle – call 0191 2321525 (5944 urgent Monday to Friday 17.00–20.00); 08448920111 – emergency 24 h advice line for poisoning/chemical exposure in pregnancy.
  • Websites: http://toxbase.org; http://toxnet.nlm.nih.gov; www.ukmi.nhs.uk. Also consult with local obstetric medicine team. The safety of any drug used in pregnancy must be checked with manufacturer’s data sheet or BNF.
  • Known or potential teratogens to stop/avoid: ACEIs, AT2 blockers, NSAIDs, statins, cigarette smoking, cocaine, warfarin, fluconazole, isotretinoin (Accutane), lithium, misoprostol, penicillamine, tetracyclines, doxycycline, thalidomide, valproic acid, cyclophosphamide, mycophenolate, sirolimus.
  • Some possible teratogens: alcohol binge drinking, carbamazepine, colchicine, disulfiram, ergotamine, glucocorticoids (benefits often outweigh risks), lead, metronidazole, primidone, quinine (suicidal doses), streptomycin, vitamin A (high doses), zidovudine (AZT).
  • Drugs to avoid when breastfeeding: chloramphenicol, metronidazole, nitrofurantoin and sulphonamides (haemolysis with G6PD deficiency), tetracycline (stains teeth and bones), lithium, antineoplastics and immunosuppressants, psychotropic drugs (relative).
  • Drugs which can be used acutely in pregnancy: heparin and LMWH, ampicillin, cephalosporins, clindamycin, erythromycin, gentamicin, paracetamol (acetaminophen), folate, pyridoxine, thyroxine, steroids, salbutamol, aspirin, magnesium, anticholinergic inhalers, theophyllines, lorazepam, diazepam, phenytoin. Give usual doses of GTN, IV nitrates, furosemide, morphine, calcium blocker, mechanical support, e.g. IABP, LVAD, Digoxin, beta-blockers.






15.3

Amniotic fluid embolism



  • About: amniotic fluid (fetal cells, hair, or other debris) enters maternal circulation. Causes cardiac arrest/shock in labour/caesarean or within 30 min post-partum. Resembles anaphylaxis.
  • Aetiology: usually during labour but also abortion and trauma. Fetal squamous cells found in the maternal pulmonary circulation. These are also found in well patients. Possibly complement activation.
  • Clinical: acutely dyspnoeic with ↓BP and hypoxia, cough, seizures, cardiac arrest. Coagulopathy or severe haemorrhage.
  • Investigations: ABG: Type 1 RF. CXR: pulmonary oedema. ECG: non-specific. Coagulation screen: coagulopathy.
  • Management: as per cardiac arrest (Section 1.2). CPR, ABCs, intubate and ventilate. Manage with IV fluids for ↓BP. Invasive monitoring and exclude alternative diagnoses. Manage any coagulopathy. Haemodialysis with plasmapheresis for AKI. Steroids if immune-mediated mechanism suspected.






15.4

Hypertension in pregnancy



  • Hypertension during pregnancy carries risks of increased perinatal mortality, preterm birth and low birth weight.
  • Pre-eclampsia and gestational hypertension come on later in pregnancy.
  • Pre-existing hypertension can be discovered at initial contact.
  • ACE inhibitors and ARB drugs are teratogenic and contraindicated in pregnancy.
















Degree

Values


Mild

DBP 90–99 mmHg and SBP 140–149 mmHg


Moderate

DBP 100–109 mmHg and SBP 150–159 mmHg


Severe

DBP >110 mmHg and SBP >160 mmHg









HTN in pregnancy (BP >140/90 mmHg, 2 readings seated 6 h apart)



  • Gestational (pregnancy-induced) HTN (new onset but minimal proteinuria).
  • Pre-eclampsia and eclampsia (new hypertension with proteinuria).
  • Chronic hypertension (renal disease, primary/essential hypertension).
  • Pre-eclampsia superimposed on chronic hypertension.






15.5

Eclampsia and pre-eclampsia



  • About: reported frequencies from 2 to 7% of all pregnancies after 20 weeks. Not all can be anticipated by finding hypertension and proteinuria. Pre-eclampsia toxaemia (PET): after 20 weeks + BP >140/90 mmHg + proteinuria >300 mg/24 h. Severe = PET + end organ damage.
  • Note: low-dose ASPIRIN helps prevent pre-eclampsia in high-risk women.
  • Risk factors: moderate risk factors: 1st pregnancy, age >40 years, pregnancy interval >10 years, BMI >35 kg/m2 at first visit, family history of pre-eclampsia, multiple pregnancy. High risk factors (give ASPIRIN 75 mg OD from 12 weeks): HTN during previous pregnancy, CKD, APL, T1DM, T2DM, chronic hypertension.
  • Clinical: pre-eclampsia: severe headache, severe pain just below ribs, epigastric or hypochondrial (hepatic congestion/liver capsule stretching). Is baby moving normally (fetal wellbeing)? Visual problems such as blurring or vomiting, flashing before eyes, sudden swelling of face, hands or feet. Disorientated, hyperreflexia, clonus, stroke and cerebral oedema. Severe pre-eclampsia: severe headache, visual problems, papilloedema, clonus >3 beats. Liver tenderness. Eclampsia: grand-mal seizures last 60+ sec preceded by facial twitching. There is generalised muscle contraction. May be coma and period of hyperventilation.
  • Complications: stroke: ischaemic or haemorrhagic get CT head, manage BP, ASPIRIN where indicated. Exclude cerebral venous thrombosis and SAH. HELLP: platelets <100 × 109/L, haemolysis (↑LDH), elevated LFTs. Fatal in 2%. AKI (acute cortical or tubular necrosis): fall in GFR, elevated creatinine, urea. Oliguria, proteinuria >5 g/24 h. Others: fetal growth retardation, fetal death, placental abruption, ARDS, hepatic infarction, DIC.

Investigations


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May 1, 2018 | Posted by in Uncategorized | Comments Off on – Medical emergencies in pregnancy

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