Understanding Anesthesiology - The Global Regional Anesthesia ...

jury, air embolism, infection, thrombosis, hydrothorax,
catheter misplacement and catheter or wire embolism.
The use of ultrasound guidance for central line insertion
allows more accurate needle placement and avoidance
of complications.
Types of Fluids
Fluids can be divided into two broad categories: crystalloids
and colloids. Crystalloids are solutions of simple
inorganic or organic salts and distribute to varying extents
throughout the body water. Examples include
Ringer’s Lactate (R/L), 0.9% saline (N/S) and 5% dextrose
in water (D5W). Sodium chloride, a common constituent
of crystalloid solutions, distributes throughout
the entire extracellular space. Glucose distributes
throughout the entire body water (extracellular and intracellular
spaces). Whatever the active solute, water,
the ubiquitous solvent, will move across membranes to
maintain osmotic equilibrium.
Colloids are suspensions of protein or other complex
organic particles. These particles cannot diffuse across
capillary membranes and so remain trapped within the
intravascular space. Examples of colloids are albumin
(5%, 25%), hydroxyethyl starches (Pentaspan ®, Voluven
® , red cell concentrates, platelets, and plasma.
The partitioning throughout the body’s compartments
of some of the various types of fluids for administration
is summarized in Table 4 and illustrated in the animated
slides, Interactive 1.1.
Normal saline or Ringer’s lactate are the preferred crystalloids
for intra-operative fluid administration and resuscitation,
as they provide more intravascular volume
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