1 Fluid Assessment Cherelle Fitzclarence 2009

Overview Revision Cases

We are approximately two- thirds water PG

JXZ

Fluid shifts / intakes Intracellular 30 litres Interstitial9 litres IV 3 litres Kidneys Gut Lungs Skin Extracellular fluid - 12 litres PG

Fluid shifts / intakes Intracellular 30 litres Interstitial9 litres IV 3 litres Kidneys Gut Lungs Skin Extracellular fluid - 12 litres PG

REGULATION OF FLUID VOLUME

BODY FLUID COMPARTMENTS RULE OF THIRDS 1. Intracellular: 2/3 (40% TBW) 2. Extracellular: 1/3 (20% TBW) a. Interstitial + Lymph: 2/3 (15% TBW) b. Intravascular: 1/3 (5% TBW)

Fluid Pressures (Starling’s Law) ECF and ICF fluid shifts occur related to changes in pressure within the compartments Fluid flows only when there is a difference in pressure 3 types of body fluids  Isotonic  Hypotonic  Hypertonic

Fluid shifting 1st space shifting- normal distribution of fluid in both the ECF compartment and ICF compartment. 2nd space shifting- excess accumulation of interstitial fluid (edema) 3rd space shifting- fluid accumulation in areas that are normally have no or little amounts of fluids (ascites)

FLUID VOLUME DEFICIT Hypovolemia: isotonic extracellular fluid deficit Deficiency of both water & electrolytes Caused by decreased intake, vomiting, diarrhea, fluid shift Dehydration: hypertonic extracellular fluid deficit Deficiency of water Caused by water loss related to high blood glucose, inadequate ADH production, high fever, excess sweating

Assessment of Fluid Deficit Hypotension Weak rapid pulse Temperature decreased if hypovolemic, and increased in dehydration Weight loss Skin turgor poor in dehydration and possible edema in hypovolemic Concentrated urine and blood

FLUID VOLUME EXCESS Extracellular: isotonic fluid excess Excess of both water and electrolytes Caused by retention of water and electrolytes related to kidney disease; overload with isotonic IV fluids Intracellular: water excess Excess of body water without excess electrolytes Caused by over-hydration in the presence of renal failure; administration of D5W

FLUID VOLUME EXCESS/Assessment Isotonic  Hypertension  Bounding pulse  Crackles, dyspnea  Weight gain  Edema in extremities  JVD  Irritable, confused  Hypotonic  Systolic B/P ^  Decreased pulse  Increased respirations  Weight gain  Cerebral edema  Irritable, confused

FLUID VOLUME EXCESS/ Treatment Isotonic  Correct cause  Restrict H2O and Na  Diuretics  Digitalis  Possible dialysis Hypotonic  Correct cause  Restrict H2O intake  IV fluids with E-lytes

Dehydration Occurs when fluid loss exceeds intake  sweating vs time Fluid lost mostly from ECF  decreased circulating blood volume inadequate tissue perfusion, inefficient transport of substrates to muscle, and elevated HR