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