1. Body Fluid Compartments
   1. water
      1. 60%
   2. Intracellular Fluid
      1. 40%
      2. Properties
         1. low sodium
         2. high potassium
   3. Extracellular
      1. 20%
      2. Intravascular
      3. Extravascular
      4. Properties
         1. protein concentration LOW
   4. Fluid Replacement
2. Fluid and Electrolyte Losses
   1. Routes
      1. kidney
      2. GI Tract
      3. Skin
      4. Respiratory Tract
3. Normal Fluid Losses
   1. Kidney
      1. control electrolyte and water balance
      2. regulated by
         1. aldosterone
            1. salt retention
            2. responds to fall in glomerular perfusion
         2. antidiuretic hormone
            1. responds to the increased solute conc.
            2. by retaining water in the renal tubules
         3. regulate circulating volume and its osmolarity
      3. damaged kidneys
         1. patient vulnerable to inappropriate water and electrolyte administration
   2. Gastrointestinal Tract
      1. organs
         1. stomach
         2. liver
         3. pancreas
      2. electrolyte-rich fluid
   3. Insensible losses
      1. inspired air
      2. skin
      3. metabolic water
   4. Normal Fluid Losses
      1. Urine
         1. 2000
         2. 80-130
         3. 60
      2. Faeces
         1. 300
      3. Insensible
         1. 400
      4. Total
         1. 2700
4. Abnormal Fluid Losses
   1. Kidney
      1. impaired tubular function
         1. resolving acute tubular necrosis
         2. diabetes inspidus
         3. head injury
         4. loss of several liters of dilute urine
      2. Production of ADH by tumours
         1. SIADH
            1. water retention
            2. haemodilution
   2. GI Tract
      1. increased in
         1. diarrhoea
         2. ileostomy
            1. colonic water reabsorption is absent
      2. loss of electrolyte-rich fluid
         1. vomiting
         2. nasogastric aspiration
         3. fistulous losses
      3. disturbance of acid-base balance
         1. pyloric stenosis
            1. acid fluid
         2. pancreatic fistula
            1. alkaline fluid
      4. large occult losses
         1. paralytic ileus
         2. intestinal obstruction
   3. Insensible Losses
      1. Hyperventilation
         1. pain
         2. chest infection
      2. Skin
         1. increased by
            1. pyrexia
            2. sweat
            3. large amount of salt
5. Effects of Surgery
   1. ADH is released
      1. Hypovolaemia
         1. aldosterone secretion
         2. salt retention
   2. damaged tissues
      1. release potassium
         1. further increased by transfusion
         2. accumulation
            1. life-threatening arrhythmias
         3. basis of recommendation
            1. not necessary to give supplementary potassium in the first 48hrs following surgery
6. Prescribing Fluids for the surgical patient
   1. majority
      1. fluid replacement
         1. for only a brief period
   2. some
      1. resuscitation
         1. preoperatively
      2. special losses
   3. severely-ill patients
      1. long-term nutritional support
7. Replacement
   1. Normal Fluid Losses
   2. Special Losses
   3. Resuscitation
8. Nutrition
9. Feeding
   1. Enteral
   2. Parenteral