PBL seen scenario 1 Flashcards
(33 cards)
Metformin MoA and side effects
Decreases hepatic gluconeogenesis
Decreases intestinal absorption of glucose
Inhibits lipolysis
Increases muscle utilisation and uptake of glucose - increasing insulin sensitivity
Side effects: Nausea and vomiting
DURING PREGNANCY: crosses placenta but safe during pregnancy and breastfeeding (not teratogenic)
Antenatal schedule
Dating scan (8-14 weeks): Determine due date and screen for possible conditions - Down Syndrome, Edwards and Patau syndromes
20 week scan:
HIV, syphilis and hepatitis B screening
Detailed USS of baby (organ development)
Sex of baby
28 weeks:
Offer screening tests
Polycystic Ovarian Syndrome Pathophysiology
Insulin resistance –> hyperinsulinaemia –> increased androgen synthesis by theca cells
Hyperinsulinaemia reduces liver production of sex hormone binding globulin (binds to free testosterone) –> free testosterone might increase
Increased androgen synthesis by theca cells can increase LH secreted by anterior pituitary
Polycystic Ovarian Syndrome Diagnosis
Rotterdam criteria:
Hyperandrogenism, oligomenorrhea, polycystic ovaries on ultrasound
PCOS Blood screen:
Raised LH, normal fSH –> raised LH:fSH ratio (>3:1)
Glucose due to raised insulin resistance
Day 21 progesterone - should be high (ovulatory phase). Released by corpus luteum; low –> no ovulation
Differential Diagnoses:
Thyroid function test, prolaction levels, Cushing’s
Polycystic Ovarian Syndrome Presentation
Hirsutism and acne Acanthosis nigricans (due to insulin resistance) Central obesity Menstrual disturbance - Oligomenorrhea - Amenorrhea
Polycystic Ovarian Syndrome Treatment
Lose weight
Treatment:
- 1st line: Clomiphene - selective oestrogen receptor blocker (brain thinks oestrogen is low –> more fSH = ovulation)
- 2nd line: Metformin (combat insulin resistance)
Laparoscopic drilling - destroys androgen producing theca and granulosa cells
Injectable Gonadotropins (fSH)
COCP - restore menstrual regularity
Surgery to remove cysts
Anti-androgens - to treat acne/hirsutism
Polycystic Ovarian Syndrome Complications
Infertility
T2D
CVD
Pregnancy complications:
Increased risk of gestational diabetes (Pregnant with PCOS –> 24-28 week test for GD) pre-eclampsia, premature labour
How is risk measured
Incidence is used as a measure of risk
number of new cases (or deaths) per 100,000 people per year
Relative risk
Incidence of disease in exposure population / incidence of disease in unexposed population
What does 95% CI represent
95% of a sample relative risk contains the population relative risk with a probability of 95%
What is a confounder
A confounder is a factor that is associated both with the exposure and the disease
Adjusting for confounders:
RR for heavy drinkers dying from lung cancer compared to non-drinkers = 2
RR for smoking (heavy drinkers dying from lung cancer compared to non-drinker) = 1
Reasons for illegitimate association between exposure and disease
- Bias
- Recall Bias
- Selection Bias
- Reverse Causality
- Confounding
- Incorrect analysis
- Chance
- Causal
Bradford Hill Criteria for Causation
- Strength of association
- Dose response
- Time sequence
- Consistency of findings
- Similar studies on different populations
- Biological plausibility
- Coherent of the evidence: other types of studies
- Reversibility
How can consultations improve adherence
Patient-centred, decision making is shared
What is adherence influenced by
Illness perception, background beliefs, concerns (perceived needs)
Self-regulatory model of illness behaviour
Identify, time-line, consequences
Influences on beliefs
Medical establishment
family/friends
Culture
Media
Health belief model
Depends on perceived susceptibility/severity/benefits/barriers and cues to action and self-efficacy
Theory of planned behaviour
- Confidence in performing behaviour
- Intentions (important indicator whether people will take action), depends on attitude and subjective norm
Diagnosis of intrauterine growth restrictions and types
Diagnosis:
Lag in symphysiofundal height of 4 weeks or more –> symphysiofundal height should increase 1cm/week in weeks 14-32
Amniotic fluid 5-25cm range (<5cm = Oligohydramnios)
Types:
Physiological foetal growth
Symmetrical/type I IUGR
Asymmetrical/type II IUGR
Physiological foetal growth
Conception - 28 weeks:
hyperplasia (increase in number of cells)
Weeks 28 - 34:
hypertrophy (increase in size of cells)
Symmetrical/type I IUGR
Aetiology: Genetics, Infection, Multiparity
Inhibition of growth in hyperplastic stage –> baby has overall less cells
Head + abdo circumference, height, width, weight all below 10th percentile
NORMAL HC:AC Ratio (1)
Asymmetrical/Type II IUGR
Aetiology: anything that causes uteroplacental insufficiency (maternal hypertension, pre-eclampsia, vasculopathies, smoking, diabetes)
Inhibition of growth in hypertrophic stage –> normal cell numbers, but cell size reduced
foetus has to redistribute cardiac output = brain and heart receive normal flow at expense of splanchnic vessels –> small abdomen
Smaller foetal kidneys –> Oligohydramnios
REDUCED/normal HC:AC Ratio (< or = 1)
folic acid and metabolism
400mg/day 3 months before conception and till 12 weeks of pregnancy (to increase chance of conception/successful preg.)
Converted to 5-MTf –> required for re-methylation of homocysteine to methionine
Methionine converted to S-adenosylmethionine (SAM), methyl donor for DNA, neurotransmitter production
Lack of folate –> homocysteine build up, CVD risk
Lack of folate also causes B12 deficiency –> macrocytic anaemia
