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12.09.20 X ray and teaching notes

Child safeguarding - Radiology
  • X-ray changes in fractures:
    • Peaks:
      • Resolution of soft tissue changes: 4-10 days
      • Sub-periosteal new bone formation (SPBNF): 10-14 days
      • Soft callus formation: 14-21 days
        • Causes loss of fracture line definition
      • Hard callus formation
        • 21-42 days
    • These processes are very variable and all overlap
      • Extremely hard to reliably date fractures
  • No-one has any idea what vitamin D deficiency does to fracture risk + healing time
    • LOADS of kids are vit D deficient
  • 50% of acute rib fractures are not visible on CXR
    • Much easier to see after callus formation
  • Brain haematomas
    • Extradural are convex
      • Lens-shaped
      • Because they're bounded by the dura
    • Subdural are concave
      • Spread out easily
  • Timing
    • CT or X ray is good for acute changes
      • Blood is bright
    • MRI is better for later changes



Asthma teaching

  • Upper airway obstruction can be very difficult to distinguish from lower airway obstruction
    • Because it's transmitted - especially in children
    • Listen all over the lungs - if the sound doesn't change, it's probably from the upper airways
  • Atopy tetrad
    • Asthma
    • Eczema
    • Allergies
    • Hay fever
  • Triad of airway narrowing in asthma
    • Muscle spasm
    • Oedema
    • Mucous
  • Pressure-Volume curves
    • Volume on the X-axis!
    • Work done is area under the line / Area enclosed by a closed cycle
    • At high lung volumes (i.e. with air trapping)...
      • Compliance is less
      • So dV/dP is lower
      • So the area enclosed by the breathing cycle is bigger
      • => Raised WOB in a hyperinflated lung
  • Biologics used in asthma
    • Omalizumab
      • IgE MAb
      • Binds free IgE
      • Useful in severe persistent allergic asthma patient who have a positive skin test or in vitro reactivity to a perennial aeroallergen
    • Mepolizumab
      • Anti-IL5
      • Doesn't work
    • Golimumab
      • Anti-TNF alpha
      • Poor side-effect profile - discontinued
    • Etanercept
      • Anti-TNF
      • Very modest improvement


Nutrition

  • Domains:
    • What you eat (nutrient balance)
    • What you are (body composition)
    • What you do (functional)
  • Birth weight definitions
    • LBW < 2500 g
    • VLBW < 1500 g
    • ELBW < 1000 g
  • Neonatal calorie requirements
    • 40 kcal/kg/day just to lie still
    • Additional 40-80 kcal/kg/day to grow, cry, etc
  • Calorie density in foods
    • Fats: 9 kcal/g
    • Glucose: 4 kcal/g
    • Breast milk: 70 kcal/100 ml
  • Weight triples between 29-40 weeks gestation
    • Much of this is fat
    • Due to increasing fetal insulin production
  • Babies can breast feed at around 33-34 weeks gestation
    • Reflexes not developed before then
  • Can't give hypertonic fluids (e.g. TPN) through a peripheral line
    • => Oedema => Leakage into tissues => Tissue damage (e.g. calcium)
  • Breast feeding => 5-fold reduction in NEC
    • Even with bank milk (pasteurised)
  • Breast feeding effect on IQ
    • Normally 2-6 point increase
    • Even more effect for pre-term babies
    • Due to lipids needed for brain development


Histories

  • DRILL DOWN
  • Home nebs
    • Why?
    • Where from?
    • Do you know how to use them?
  • Food allergy
    • What happens?
    • Have you consulted anyone?
      • Who were they?
      • Were they medically trained or just a "nutritionist"
        • NB Dieticians are registered and licensed but most other "nutritionists" aren't
    • What medication do you have?


Notes

  • Eczema first presenting in the first year of life tends not to persist
  • Croup really just refers to the noise (from any cause)
    • What we mean is laryngotracheobronchitis (LTB)
  • Anion gap is predominantly due to proteins
  • RDS => Chronic lung disease of prematurity
    • WOB in RDS rips lungs apart within 15 mins
    • => Usefulness of HFOV
  • Base excess is measured in mmol/L
    • => Direct measure of how much bicarb you need to use to correct acidosis
    • Normally only "half-correct" to avoid giving too much sodium
  • Fluid from a ruptured Baker's cyst tracks down between soleus + gastrocnemius and gives calf/Achilles pain
  • The most dangerous thing about home nebs is being falsely reassured by decreased WOB, when it's actually due to exhaustion
    • Crucial to monitor sats
  • Spacers must be held at 45 degrees when used with a face mask, to keep the valve open
  • Term is 37 - 42 weeks
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