• Non-obstetric surgery during pregnancy
    • Laparoscopy can be done safely: smaller incision, early mobility, decreased pain.
    • Airway may be difficult due to breasts, oedema.
    • There is no increase in fetal abnormalities but there is increased IUGR, LBW & spontaneous abortion.
    • Timing
      • Delay surgery if possible
        • Postpone elective surgery
        • Perform >6/52 post-partum
      • Liase with obstetric team, consider site with pads/obs cover.
        • Intra-op fetal monitoring once viable (~25/40)
      • Third trimester
        • Consider c-section prior to major surgery
          Steroids 48hrs prior
    • Drugs
      • LA if possible
      • Thiopentone has a more proven safety record versus propofol (though this is used by some in early pregnancy)
      • Benzodiazepines: single dose probably safe but chronic use associated with cleft lip
      • Ketamine can increase uterine contraction.
      • Avoid NSAIDS, due to closure of the PDA and early fetal loss
      • Suxamethonium action longer due to low levels of PCE
      • Avoid prolonged exposure to nitrous oxide (?teratogenic)
      • Neostigmine can cause fetal bradycardia
      • Muscle relaxants
        • Generally ionised so don't cross placenta in significant amounts
    • Anaesthesia
      • Maternal hypoxia leads to uteroplacental vasoconstriction and hypoperfusion
      • Maternal hypercarbia causes reduced uterine blood flow due to uterine vasoconstriction (as does hypocarbia)
      • Maternal hypotension should be treated promptly
      • Avoid aorto-caval compression from 20/40
      • Consider a smaller ETT
      • Volatiles increase uterine blood flow up to a MAC of 1.5 then decreases in MAP offset this
      • Tocolytics may be used if premature labour occurs
        • Magnesium
        • Terbutaline
        • Nifedipine
        • GTN
        • Atosiban
    • Main aim is to preserve uteroplacental blood flow
    • Physiological changes during pregnancy
      • CVS
        • Inc plasma volume 50%, inc RCV 15%, inc CO ~ 40%, dec DBP 15%, dec SVR 15%, aortocaval compression
      • Resp
        • Increased MV 45%, decreased FRC 10-25%, increased O₂ consumption of 20%, decreased PaCO₂.
      • CNS
        • Decreased MAC 20-30%
          Reduced ED of IV sedatives/hypnotics. Epidural veins distended, smaller capacity of space in epidural => inc spread of LA
      • Renal
        • Increased GFR, renal glucosuria
      • GI
        • Increased gastric volume/acidity
      • Coagulation
        • Increased activity of coagulation factors
      • Endocrine
        • Insulin sensitivity inc in 1st trimester
          Later, there is increased insulin resistance
    • CEACCP
      Link:ceaccp.oxfordjournals.org/content/6/2/83.full.pdf