Obstetric pharmacology Flashcards
What are the physiological changes in associated with pregnancy?
Increased: Heart Rate, Stroke volume, Cardiac output, blood volume, oxygen consumption
Decreased: total peripheral resistance, mean arterial blood pressure
What is the equation that describes Uterine blood flow (UBF)?
Flow = (Change in pressure)/(resistance)
UBF = (Uterine artery pressure - uterine venous pressure)/(uterine vascular resistance)
What are the functions of the placenta?
T - Transport of substances
I - Immunological
M - Metabolic (including drug inactivation)
E - Endocrine
What is a teratogen?
Any substance that causes any significant postnatal change in function or form, after prenatal treatment. Morphological, biochemical and behavioural changes.
Name four broad categories of human teratogens.
Environmental and physical agents
Infections
Maternal metabolic imbalance
Drugs and Chemicals
What are the biggest causes of maternal mortality in developing and developed countries?
Developed: Cardiac disease
Developing: Haemorrhage
What is the purpose of Dexamethasone administration in preterm labour?
Improvement of foetal lung maturity.
What are the three goals of acute management of obstetric haemorrhage?
Control the bleeding
Restore adequate oxygen-carrying capacity
Maintain adequate tissue perfusion
What are the two most important drugs for treatment of obstetric haemorrhage?
Oxytocin -> smooth muscle contraction
Ergometrine -> smooth muscle (+Vascular SM) contraction.
What is the intravenous fluid used to treat obstetric haemorrhage?
0.9% isotonic sodium chloride
What is the purpose of Magnesium sulphate treatment in Preeclampsia?
Treatment and prevention of seizures in women with preeclampsia.
Reduces intracellular calcium concentration.
Magnesium is a weak clacium channel antagonist that regulates calcium influx through the NMDA receptor in neuronal tissue.
May reduce ischaemic neuronal damage caused by anion flux.
What is the role of Labetalolin treatment of pre-eclampsia?
Competitive non-selective alpha and beta-adrenoceptor antagonist and that has membrane stabilising properties at higher doses.
