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Clinical Chemistry and the Geriatric patient_1_

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					Clinical Chemistry and the
      Geriatric patient
                   Aging means to grow older       •
Several physiological changes occur as people      •
                                            age
                    These changes are gradual      •
  Deterioration results from time-dependent,       •
                           irreversible changes    •
    These changes will be reflected in clinical    •
                         laboratory test results
 Life expectancy is increasing, for persons born in •
   1900(47years) to (77years) for persons born in
                                               2001
    This gain is due to improved sanitation, better •
     medical care and increased use of preventive
                                     health services
Geriatrics is the branch of health care concerned •
with the care of the aged, including physiological,
        pathological, psychological, economic and
                              sociological problems
            Gerontology is the study of the aging
 processThe demand on the health care system
by geriatric patients is different from that of the
                              rest of the population
    Health care will need to shift its emphasis to
                   meet the need of chronically ill
     As the population ages, increase in chronic
 diseases such as cancer, arthritis, hypertension
                        and diabetes are expected
 This means more physician office visits, hospital •
                         stays and laboratory tests
   The clinical laboratory professional must treat •
 the patient with dignity and respect. They must
be aware of special considerations regarding the
    collection of blood samples, development of
    reference intervals, effect of medications on
                                 chemistry results.
   They must understand the effects of aging on •
                                 laboratory values
    Current Theories of Aging
                    1- Random Genetic Damage        •
                                       -Mutation    •
-Background Radiation Damage e.g ultraviolet        •
   rays which may cause chromosome or DNA
                                         damage
       -errors in chromosomal translocation or      •
                                    transcription
                         2- glycation of Proteins   •
 Interfere with both cell structure and function    •
                                  3- Developmental Theories       •
                       -Immune and Neuroendocrine System          •
    ..Immune system declines with age e.g thymic atrophy,         •
reduction of B and T cell population, decreased response to
     neoantigens, misfolding of proteins which may lead to
                                                  amyloidosis
                          4- Genetically Programmed Theory        •
                                        defects in apoptosis..    •
                               5-Free Radicals(OH, O2, NO…)       •
                                       Cause damage to cells      •
  N.B delay of aging in rodents was accomplished by calorie       •
                                                    restriction
 Diseases and Disorders commonly
       associated With Aging
  Atherosclerosis( e.g myocardial infarct, renal •
                                  disease, stroke)
                                            Cancer
                                Diabetes mellitus
                           Hyperparathyroidism
                                Hyperthyroidism
                                 Hypothyroidism
Monoclonal gammopathies(e.g multiple myeloma)
                                     osteoporosis
The Top Ten Leading Causes of Death
         (Age 65 and Older)
                                      heart disease   •
                                            Cancer    •
                                             Stroke   •
                 Chronic lower respiratory disease    •
      Accidental death due to unintentional injury    •
                                          Diabetes    •
                                 Alzheimer disease    •
                           Influenza or pneumonia     •
      Nephritis, nephrotic syndrome or nephrosis      •
                                        Septicemia    •
Changes in Selected Clinical Chemistry
          Analytes With Age
                                A- Increase   •
                                       GGT    •
                              ALP(women)      •
                         Alpa-1 antitrypsin   •
                                   Amylase    •
                                        AST   •
                                       BUN    •
                                         CK   •
                         Gammma globulin      •
                           Fasting Glucose    •
                                       HDL    •
Increase
     Inorganic Phosphate     •
                      LDH    •
                     PCO2    •
                         K   •
        Total Cholesterol    •
           Triacylglycerol   •
                      TSH    •
                Uric Acids   •
Decrease
                   Albumin      •
                Aldosterone     •
                    Bilirubin   •
       Creatinine Clearance     •
                       DHEA     •
          Growth Hormone        •
                         PO2    •
                           T3   •
               Total Protein    •
               Transferrinss    •
Unchanged
                     Chloride    •
                      Cortisol   •
                      Free T4    •
                 Haptoglobin     •
              Insulin(fasting)   •
        PH or Slight decrease    •
                           Na    •
        T4 or Slight decrease    •
 Thyroid-binding globuli(TBG)    •
     Endocrine Function Changes
   Changes in the production of hormones by sex      •
     organs, thyroid, pituitary and adrenal glands
 The most notable changes relate to the gonadal      •
                            and thyroid hormones
A decrease in the gonadal production of estrogen     •
   in women(menopause) and of testosterone in
                                 men(andropause)
                       The adrenal production of     •
      dehydroepiandrosterone(DHEA) and DHEA
                             sulfate(adrenopause)
     Decrease in the growth hormone-insulin-like    •
            growth factor(IGF) axis(somatopause)
       Hormone replacement regimens are being       •
developed as a strategy to delay or prevent some
                     of the consequences of aging
  Dysregulation of apoptosis may be the cause of    •
  diseases such as cancer and neurodegenerative
 disorders(e.g Alzheimer and Parkinson diseases)
 The major consequences of estrogen deficiency      •
                        are osteoporosis and CHD.
Major risk factors of osteoporosis include diet, •
     inactive life style, genetic predisposition,
         smoking, endocrine disturbances and
                                     medications
            The greatest problem secondary to •
                     osteoporosis is hip fracture
   An association between hypovitaminosis D •
     and secondary hyperparathyroidism and
            osteoporotic changes in the elderly
The prevelance of hypertension also increases •
  with age, about 60% of people older than 60
                     years having the condition.
Causes include increased peripheral resistance •
     due to atherosclerosis, chronic renal and
endocrine disorders and multiple medications.
     There is also a decline in the efficiency of •
                       homeostatic regulation.s
      Diabetes mellitus and insulin resistance    •
                          increase with aging.
   Consequences of D.M such as retinopathy,       •
          nephropathy and CVD also increase
Renal function changes as indicated by kidney     •
          function tests is common in elderly.
   Hepatic function disorders are observed in     •
                                       elderly.
Pulmonary Function and Electrolyte
            Changes
                                  PO2 decreases     •
                                 PCO2 increases     •
                               Na/Cl no changes     •
                                K slight increase   •
  Respiratory-related diseases are prevalent in     •
                                  elderly people.
   Diseases include chronic bronchitis, chronic     •
obsrtuctive pulmonary disease, neoplasia, lung
     infections particularly T.B and pneumonia
 Cardiovascular and Lipid Changes

Atherosclerosis develops slowly followed by •
    hypertension, hemorrhage, thrombosis,
                              stroke and CHD
         Hyperlipidemia plays major role in •
    atherosclerotic process and risk for CHD
Cholesterol, triglyceride, HDL levels increase •
                                    with aging
          Enzymes
The following enzymes show increased     •
                             activity:
                                 AST     •
                                 ALP     •
                                 GGT     •
                                   CK    •
                                 LDH     •
                             Amylase     •
   Establishing Reference Intervals for
                the Elderly
  It is difficult to establish RI for the elderly due to •
        differences in physiological and pathological
           condition of each individual, however the
       following factors should be considered when
               interpreting clinical laboratory results:
Exercise, Medications, Mobility, Nutritional status, •
    personal habits, Alcohol use, Smoking, Chronic
       disorders, trauma………and special conditions

				
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posted:4/30/2014
language:English
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