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Age-related changes

From Mediwikis

The “Geriatric Giants”

  • Immobility causes constipation, pressure sore, DVT and hypostatic pneumonia
  • Instability- falls
  • Incontinence
  • Decreased Intellectual ability
  • Impaired hearing and vision
  • Infection, immune deficiency
  • Irritable colon
  • Isolation
  • Insomnia
  • Impotence
  • Impaired endocrine

Definitions:

  • Impairment- any loss of anatomical, physiological, or psychological function
  • Disability- Restricted or no ability to perform a function within the normal range which makes the patient dependent on others
  • Participation Restriction- Unable to take part in daily activites

Example (Osteoarthritis)

  • Impairment- Unable to bend knee
  • Disability- Unable to walk far
  • Participation Restriction- Unable to walk to shops

Lungs

  • Forced Expiration Volume in 1 second (FEV1) undergoes steady decline from the age of 30 but only clinically significant in 60s
  • Lungs and chest wall decrease in elasticity and muscle strength
  • Gas exchange is reduced due to decreased recoil and surface area
  • Ventilation control from CNS is less tightly controlled
  • Decrease in protective reflexes increasing likelihood of pneumonia

BP

  • Increases with age mainly systolic
  • Large elastic arteries become thicker and stiffer
  • Ageing alone will not cause hypertension (140/90) other precipitating factors must be present
  • Leg pain when walking due to stiffening peripheral vessels
  • Postural hypotension autonomic reflex. Systolic BP drop of 20mmHg or a drop of 10mmHg in diastolic in 5 mins of standing

Endocrine

  • Plasma glucose and insulin a higher. Glucose levels peak at a later stage
  • Insulin levels are the same but sensitivity decreases therefore generating a higher risk of diabetes
  • There is decreased sensation of osmoregulation higher risk of dehydration as feel less thirsty

Drugs

  • Decreased first pass metabolism- decreased liver blood flow, decreased distribution volume
  • Increased passage at Blood Brain Barrier
  • Decreased tissue sensitivity
  • Decreased renal and hepatic clearance

Immunity

  • Decreased T helper lymphocytes
  • Decreased thymus gland
  • Decreased B cell antibody production
  • Decreased mucosal immunity
  • Less autoimmune diseases
  • Higher risk of shingles

Renal

  • Decrease in kidney size and blood flow
  • Decreased Glomerular Filtration Rate
  • Less renin and aldosterone (act on DT to increase sodium reabsorption in exchange for potassium and protons- this increases water retention)
  • Decreased creating clearance due to less muscles:

140- age x weight Serum creatine x 1.23

Eye

  • Thicker and denser lense
  • Ciliary muscles are weaker affecting refraction
  • Floaters in vitreous humour
  • Presbyopis- need for reading glasses

Ear

  • Degeneration of hairs in the cochlea
  • Presbyacusis- loss of high frequency hearing

Brain

  • Sulci visible as brain shrinks
  • Decreased cerebral blood flow
  • Loss of neurones and neuronal connections
  • Working and episodic memory decreased

Bone

  • Perimenopausal bone loss
  • Osteoporosis is >2.5 SD below for bone mineral density

Muscle

  • Decrease in mass and strength
  • Changes in gait