Intravenous Fluid Therapy

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Intravenous Fluid Therapy
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Fluid Compartments

• Total body consists of 60 water by weight in
  adults
• Body fluids divided into
• Intracellular compartment
• Extracellular compartment, further divided into
• Interstitial compartment
• Intravascular compartment

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Fluid Compartments
Extracellular Fluid 1/3
Intracellular Fluid 2/3
Interstitial Fluid75
Intracellular Fluid
Intravascular Fluid25
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Intravascular Compartment

• Consists of
• Cellular components of blood
• Proteins
• Ions mainly sodium, chloride and bicarbonates
• Potassium only a small portion in plasma
• Normal blood volume is about 72 mL/kg of body
  weight

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Interstitial Compartment

• Larger than intravascular compartment
• Water and electrolytes pass freely between blood
  and interstitial spaces, which have similar ionic
  composition
• Plasma proteins are not free to pass out of the
  intravascular space unless there is damage to
  capillaries, e.g., septic shock or burns
• With fluid loss or fall in blood pressure, water
  and electrolytes pass from interstitial
  compartment into blood (intravascular) to
  maintain volume (physiologic priority)

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Intracellular Compartment

• Water within cells Largest reservoir of body
  water
• Ionic composition different from extracellular
  fluid
• Contains high concentration of potassium ions and
  low sodium and chloride ions
• Normal saline given IV Tends to remain in
  extracellular compartment
• Glucose solution gets distributed throughout all
  body compartments
• Pure water given IV Causes massive hemolysis
  (dangerous)

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Principles of Fluid Therapy

• Fluid replacement should be as close as possible
  in volume and composition to those fluids lost
• Acute losses should be replaced quickly
• Chronic lossesreplace with caution rapid
  infusion may cause fluid overload and heart
  failure
• Better replaced by oral or rectal rehydration
• Mostly deficient in water Do not overload with
  sodium

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Fluid Therapy during Operation

• Use salt solution Normal saline or Ringers
  lactate
• Preload 1 L before spinal anesthesia
• Ketamine anesthesia does not need preloading
• Maintenance fluid 4mL/kg/hour

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Fluid Therapy during Operation

• Replacement for the loss of fluid
• Blood loss replace with crystalloid 3 times the
  volume of blood loss
• Blood loss more than 1 L consider giving blood
• Desirable to have a hemoglobin minimum 89 mg
  after surgery

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Estimation of Blood Loss

• Subjective
• Fully soaked and dripping mop approximately 100
  mL
• Monitor heart rate, blood pressure throughout the
  operation
• Urine output 0.5 mL/kg/hr considered adequate
  fluid replacement

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Fluid Losses

• Assessment
• History from patient
• Type of fluid loss Vomiting, diarrhea, fistula
• How long?
• Feeling of thirst?
• Examine the patient
• Dry skin, decreased skin turgor/elasticity
• Pulse, blood pressure, peripheral circulation and
  urine output

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Abnormal Fluid Losses

• Normal loss of Na and K ions 1 mmol/kg/hr
• Loss of water ½ mL/kg/hr ( ½ mL/kg/hr by
  kidney)
• Abnormal losses
• Increased sweating in hot environment
• Fever 1 degree rise10 higher than normal
  fluid requirement per day
• Gut losses diarrhea
• Renal losses including diuretics and diabetes
• Trauma (third space loss) burns

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Types of IV Fluids

• Crystolloids
• 5 dextrose in aqua
• 5 dextrose in NaCl
• Normal saline (NaCl)
• Hartmans solution
• Ringers lactate solution
• Cholera saline
• Colloids
• Dextran 40, 70
• Gelatin preparations e.g., Haemacel
• Hetastarch, Pentastarch

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Distribution of IV Fluids in Body Compartments
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Fluids for IV Replacement