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