• Maternal Physiology
    • pregnancy
      • progesterone
        • bronchodilation
        • vasodilatation
        • smooth muscle relaxation
        • decreased GI motility
      • changes
        • resp
          • MV increased 50%
            • respiratory alkalosis, pCO2 = 4
            • compensatory reduction in HCO3-
          • FRC reduced 20%
          • VO2 increased 35%
          • decreased chest wall compliance, no change in lung compliance = decreased overall compliance
          • enlarged tongue and epiglottis
            • —> 1/300 difficult intubation (normally 1/3000)
        • cardio
          • Plasma volume increased 50%
            • (oestrogen stimulates RAS)
          • Red cell mass increased 20%
            • (increased erythropoietin in response to dilutional anaemia)
          • overall decrease in haematocrit
          • Co increased 50% (SV and HR each increased 25%)
          • decreased SVR (progesterone)
          • overall decrease in BP by 10%
          • reduced serum albumin
            • oedema
            • lower drug doses needed
        • GI
          • LOS tone decreased
            • heartburn in 80%
            • RSI needed from start of 2nd trimester
          • gastric emptying the same
          • reduced GI motility
            • constipation
    • Pre-eclampsia
      • 5-6% of pregancies
      • Triad
        • HTN
        • Proteinuria
        • Oedema
      • Dx after 20 weeks
      • Increased thromboxane
      • Decreased prostaglandin
      • Tx: delivery, labetolol, magnesium to terminate eclampsia (aim for 3.5mmol/L)
        • Mg concs (mmol/L)
          • 2
            • hyporeflexia
          • 2.5
            • prolonged AV conduction
          • 4
            • loss of patellar reflex
          • 5
            • resp depression
          • 10
            • heart block
          • 12.5
            • cardiac arrest
      • HELLP
        • In 50% of cases
        • Haemolysis
        • Elevated liver enzymes
        • Platelet dysfunction
    • labour
      • placenta
        • praevia
          • I
            • low lying
          • II
            • meets edge of os
          • III
            • partially covers os
          • IV
            • completely covers os
        • accreta
          • adherent to myometrium
        • increta
          • invades myometrium
        • percreta
          • penetrates myometrium
      • oxytocics
        • induce labour
        • ensure uterine contraction and reduce bleeding after delivery at C-section
        • cause vomiting, hypotension (ergometrine - hypertension), tachycardia, also have ADH-like properties (similar to ADH, both posterior pituitary)
        • e.g.
          • oxytocin
          • ergometrine
            • alpha-1, 5HT and Dopamine agonist
          • syntocinon (the 2 combined)
          • prostaglandin F2-alpha
            • carboprost
      • tocolytics
        • terbutaline
        • Mg
        • ritodrine
        • indomethacin
        • GTN
        • salbutamol
        • volatiles
          • not nitrous
        • Ca blockers
          • nifedipine
        • ‘Tocolytics make RIGS Vagina Close’
        • not NMB’s! (only affect skeletal muscle tone)