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Calcium disorders - Coggle Diagram

- - - - Impaired water concentration
        
        Renal stone formation
    - - Mood change
      - Depression
      - Nausea
      - Anorexia
    - - Possible competition with inward Na movement
    - - Shortened QT interval
  - - - Causes
        
        IV albumin
        
        Venous stasis
        
        Dehydration
  - - - Many patients are found on routine screening with minimal symptoms
      - Most common cause of hypercalcaemia in outpatients
      - Main cause are growths on the parathyroid glands
        
        90% are solitary adenomas
        
        Sometimes its caused by hyperplasia of all 4 glands
        
        Very rarely caused by carcinoma
      - Most common by 60 years of age
      - Diagnosis
        
        Physiological factors
        
        Low phosphate and bicarbonate
        
        Normal or moderately increased alkaline phosphatase
        
        Raised Ca2+ with inappropriately raised PTH
        
        Further investigations
        
        parathyroid imaging scan (sestamibi scan)
      - Treatment
        
        Mild cases managed by monitoring of serum calcium / PTH
        
        Where surgery may be difficult, drugs to lower calcium required
        
        Definitive treatment is removal of adenoma
        
        Drugs
        
        Bisphosphonates
        
        Patients must be rehydrated before use
        
        Furosemide
        
        Patients must be rehydrated before use
        
        Calcitonin
        
        Inhibits osteoclast action
        
        Often given together
        
        Glucocorticoids
        
        Inhibit vitamin D conversion to calcitriol
        
        Calcimimetic drugs
        
        Bind to Ca2+ sensory and inhibit PTH release
        
        Restricted drugs barely used
        
        Acute cases may need quick treatment for high calcium
        
        Re-hydration
        
        Drugs
      - Women suffer more than men on a 3:2 ratio
    - - An appropriate increase in PTH in response to hypocalcaemia
    - - Where appropriate PTH increase becomes overly active and inappropriate
  - - - Up to 20-30% of cancer patients may develop hypercalcaemia during illness
        
        Because endocrine factors secreted by malignant cells act on bone
        
        Because metastatic tumour deposits in bone locally stimulate bone resorption via osteoclast activation
    - - Solid tumours may secrete PTHrP
        
        Shows structural homology to PTH and shares similar actions
        
        Where PTHrP is the cause, its known as humoral hypercalcaemia
      - Some tumours possess 1-OHase activity and synthesise calcitriol
        
        E.g., Hodgkin's lymphoma
    - - Myeloma cells produce cytokines that activate osteoclasts
        
        IL-6
        
        RANKL
        
        IL-3
      - Metastatic breast tumours may locally produce PTHrP
      - Most commonly associated with breast and lung cancers, multiple myeloma
      - Secretion of osteoclast activating cytokines or other fatcors into the bone microenvironment
      - Approximately 20% of cases
    - - Tends to high phosphate
      - Alkaline phosphatase may be very high
        
        Liver or bone metastases
      - Raised Ca2+ and suppressed PTH
      - Often clear from prev history of malignant disease
    - - Rehydration
      - Use drugs to lower calcium if necessary
      - Treat the underlying malignancy
        
        E.g., surgery, chemotherapy
  - - - Rare
      - Ca2+ sensor on parathyroid gland is less sensitive to Ca2+ suppression of PTH
      - Overall normal-high PTH range
      - Ca2+ levels mildly high
      - Urine Ca2+ excretion low
      - Benign condition not in need of treatment
    - - Sarcoidosis
        
        Usually effects lungs
        
        Increase in calcium with a neutral PTH
- - - - Anxiety and fatigue
      - Cramps, carbo-pedal spasm, bronchial or laryngeal spasm
      - Numbness and paraesthesia
      - Seizures
    - - Mental confusion, psychoneurosis
      - Impaired intellectual ability
      - Personality changes
  - - - Acute phase response low albumin
      - Malnutrition or malabsorption
      - Liver disease
      - Nephrotic syndrome
  - - - Chronic renal disease
      - Chronic liver disease
      - Malabsorption
      - Defective 1-OHase
      - Inadequate dietary sources
      - Defective 1,25-D3 receptor
      - Lack of sunlight
    - - Bone pain
      - Fractures
      - Disordered growth in children
      - Low calcium
      - Low plasma vitamin D
      - High PTH
      - Phosphate tends to low
      - Often raised ALP
    - - Pathological bone problem
      - Osteoid laid down by osteoblasts not adequately calcified
      - Osteoid content in bones increases at the expense of normal calcified osteoid
      - Bones are softened, weak and susceptible to fracture
      - Biochemistry
        
        Increased urinary phosphorus
        
        Decreased Calcitriol
        
        Decreased serum phosphprus
        
        Increased parathyroid hormone
        
        Decreased calcium
  - - - Suppressed secretion
        
        E.g., low Mg levels or maternal hypercalcaemia
      - Developmental parathyroid problems
      - Surgical damage
      - Genetic /familial disorders
    - - Inappropriately low PTH
      - Phosphate may be increased
      - Low Calcium
    - - Normally give oral calcium and vitamin D
        
        May be given in various forms
        
        Injection if malabsorption is present
        
        In the 1-OH form is renal function is impaired
      - Close monitoring of plasma calcium concentration
      - IV calcium in acute situations
  - - - Disruption of microarchitecture
    - - Assess bone mineral density