Clinical Nutrition
                                           Outline
                   •   Malnutrition
                        -  definition
                        -  types
                   •   Physiology
                        -  fasting
                        -  starvation
                        -  effects of stress & trauma
                   •   Nutritional Assessment
                        -  presence & degree of malnutrition
                   •   Nutritional Support
                        -  who benefits
                        -  proper timing
                        -  enteral vs. parenteral
                        -  simple calculations
   Clinical Nutrition
                                         Nutrition
    •  intake of nutrients to provide energy for…
         -  performance of mechanical work
         -  maintenance of organ/tissue function
         -  heat production
         -  maintenance of metabolic homeostasis
    •  TEE (total energy expenditure)
         -  REE or BEE (fasting resting or basal energy expenditure) ~ 70%
            (~1 kcal/kg/hr)
         -  activity expenditure ~ 20% avg. but very variable
         -  thermic effect of feeding ~ 10% (intake increases the metabolic rate)
   Clinical Nutrition
                                       Malnutrition
     •  estimated that >50% of hospitalized patients exhibit malnutrition
     •  results in the catabolism of energy stores
         -  adipose (oxidation of triglycerides) ~ 13kg in average person
         -  glycogen (glucose) ~ 0.5kg, mostly in muscle
         -  protein (not stored - in use by the body)
              • skeletal muscle ~ 6-12 kg
              • other protein stores (organs, visceral proteins, nerve tissue) ~ few hundred grams
   Clinical Nutrition
                               Types of Malnutrition
     Marasmus
         -  cachexia
         -  chronic calorie malnutrition – relatively balanced diet, but too little for too long
         -  usually the result of a longstanding problem (months)
         -  see wasting of fat, skeletal muscle (weakness)
         -  visceral protein stores less affected
     Kwashiorkor (West African term – “disease of the displaced child”)
         -  “malnourished African child” (after weaning) with edema and protuberant abdomen
         -  more rapid development and worse prognosis
         -  chronic protein malnutrition (unbalanced diet) and the presence of physiologic stress
         -  fat & skeletal muscle reserves are less depleted (carbohydrates drive insulin)
         -  visceral protein stores & immunity are affected early
     Marasmic kwashiorkor
         -  combined features – usually what is seen in ICU / ill patients
         -  malnurished person with stress of illness (hypermetabolic state)
         -  worst prognosis – nutritional support tends to only increase fat mass unless the 
            underlying stressors are reversed
   Clinical Nutrition
                                Early Fasting Human
       fuel                             (Day One)                           consumption
      supply
    Circulating
       glucose                             Liver                                 CNS
                                         glycogen              glucose
     Muscle        amino acids
    glycogen                         gluconeogenesis                             PNS
    & protein                                                                  Medulla 
                   glycerol                                     lactate         Marrow 
                                                               pyruvate          Eyes
    Adipose                            FFA oxidation
        &                             in mitochondria                          Muscle
    circulating    fatty acids                                 ketones          Heart
     FFA & TG
                                                                               Kidney