Page 840 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

CHAPTER 64: Sepsis, Severe Sepsis, and Septic Shock 571

TABLE 64-3 Comparison of Crystalloid Formulations
Osmolarity Duration of Colloid Oncotic Intravascular Volume
−
+
Na (mEq/L) Cl (mEq/L) K (mEq/L) Mg (mEq/L) Ca (mEq/L) (mosm/L) effect (h) Pressure (mm Hg) Expansion (%)
2+
2+
+
Plasma 140 103 4 2 5 290
Crystalloids
0.9% NaCl (normal 154 154 — — — 308 0.5-4 0 25
saline)
5% dextrose in 0.9% 154 154 — — — 560 0
NaCl (D5NS)
Ringer lactate (LR) 130 109 4 — 3 273 0.5-4 0 25
5% dextrose in water 0 0 — — — 252 0
(D5W)
0.45% NaCl (1/2 NS) 77 77 — — — 154 0.5-4 0 15
5% dextrose in 0.45% 77 77 — — — 406 0
NaCl (D51/2NS)
7.5% NaCl (hypertonic 1283 1283 — — — 2567 0.5-4 0 400
saline)
Comparison of Colloid Formulations
Colloids
Intravascular
2+
Mg Osmolarity Molecular Duration of Colloid Oncotic Volume
Na (mEq/L) Cl (mEq/L) K (mEq/L) Ca (mEq/L) (mEq/L) (mosm/L) pH Weight (kD) Effect (h) Pressure (mm Hg) Expansion (%)
+
2+
+
−
Albumin (5%) 130 130 <1 309 6.4 69 12-24 20 100
Albumin (25%) 130 130 <1 312 6.4 69 12-24 100 500
6% hetastarch 154 154 — 310 5.5 450 8-36 30 100
in 0.9% NaCl
(Hespan)
6% hetastarch in 143 125 3 5 0.9 307 5.9 450 8-36 30 100
LR (Hextend)
6% hydroxy- 154 154 — — — 308 4-5.5 130 6-24 100
ethyl starch in
0.9% NaCl
10% Pentastarch 154 154 — — — 325 5 280 12-24 60 150
Dextran-40 154 154 — — — 280-324 4.5-7.0 40 1-2 30 150
(10%)
Dextran-70 (6%) 154 154 — — — 280-324 4.5-7.0 70 8-24 24 100

Crystalloids: Of the two main types of intravenous fluids for volume membrane according to Starling equation. Thus, COP directly alters
expansion, crystalloids are aqueous solutions of mineral salts or other fluid flux between the intravascular and extravascular space and related
123
water-soluble molecules. The most commonly used crystalloid fluid tissues. Starling equation quantifies how hydrostatic forces and COP
is normal saline, a solution of 0.9% sodium chloride, making it nearly influence fluid filtration across a capillary membrane, permitting esti-
equivalent to the tonicity of blood (isotonic). Ringer lactate or Ringer mation of therapeutic effects when factors are manipulated. For states of
acetate is another relatively isotonic solution, with acetate or lactate altered capillary permeability, such as sepsis, tissue edema may develop
added, respectively, as a bicarbonate precursor. When administering and may be aggravated by reductions of intravascular COP, favoring net
crystalloid solutions for sepsis resuscitation, isotonic solutions are fluid egress from the vasculature. 123,124 The smaller infusion volumes and
recommended to maximize the fluid that remains in the intravascular shorter time to reach resuscitation goals have been shown clinically in
space rather than hypotonic fluids that redistribute to the interstitial patients with sepsis. In addition, maintenance of COP may prevent
125
or intracellular space, or hypertonic fluids that dehydrate those spaces. pulmonary edema, while the administration of albumin to patients
126
Besides lower acquisition costs, crystalloids have the advantage of with existing pulmonary edema does not worsen the edema state as long
being universally available and easily stored and transported. Despite as hydrostatic pressures remain stable. 127
the side effects of creating interstitial edema and hyperchloremic Numerous attempts have been made to reconcile the difference
metabolic acidosis with large volume or rapid administration, they are between using crystalloids and colloids for fluid resuscitation in sepsis.
the most commonly used fluid therapy in the United States. 117 In 2004, the American Thoracic Society released a consensus statement,
concluding that colloids have not been convincingly shown to improve
Colloids: Colloids contain larger particles, such as proteins or complex clinical outcomes in any critical illness despite their physiological
sugars, suspended in an electrolyte solution. The distinguishing feature benefits and evidence supporting more rapid resuscitation with lower
of colloids is their influence on the colloid osmotic pressure (COP), volumes of administration. 124,128 Systematic reviews and meta-analyses
which affects various biosynthetic processes and protein synthesis, but have compared crystalloids with hydroxyethyl starch (HES), gelatin, and
more importantly it influences fluid movement across a semipermeable albumin as the most commonly used colloids. 118

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