Intravenous Fluids

Overview

Fluid compartments of the body

• Intracellular fluid Intracellular fluid The fluid inside cells. Body Fluid Compartments ( ICF ICF The fluid inside cells. Body Fluid Compartments):
  • All fluid enclosed in cells by plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products membranes
  • Approximately 60%–65% (⅔) of the total body water Total body water Body Fluid Compartments ( TBW TBW Body Fluid Compartments)
  • The fluid volume tends to be very stable because the amount of water in living cells is closely regulated.
• Extracellular fluid Extracellular fluid The fluid of the body that is outside of cells. It is the external environment for the cells. Body Fluid Compartments (ECF):
  • Fluid outside the cells
  • 2 primary constituents:
    • Plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products (the fluid component of the blood): approximately 10% of TBW TBW Body Fluid Compartments
    • Interstitial fluid Interstitial fluid Body Fluid Compartments (IF) surrounding all cells: approximately 25% of TBW TBW Body Fluid Compartments
• TBW TBW Body Fluid Compartments = 60% of total body weight = ICF ICF The fluid inside cells. Body Fluid Compartments + ECF

Movement of water across the compartments

• From plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products to IF:
  • Occurs via Starling forces Starling Forces Capillaries: Histology acting across the capillary membrane
  • Capillary pressure (Pc) pushes fluid out of the capillary.
  • Interstitial fluid Interstitial fluid Body Fluid Compartments pressure (Pif) pushes fluid into the capillary.
  • Plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products colloid osmotic (oncotic) pressure (πc) pulls fluid into capillary.
  • Interstitial fluid Interstitial fluid Body Fluid Compartments colloid osmotic pressure (πif) pulls fluid out of the capillary.
• From ICF ICF The fluid inside cells. Body Fluid Compartments to ECF:
  • Occurs via osmosis Osmosis Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane. Body Fluid Compartments across the selectively permeable cell membrane Cell Membrane A cell membrane (also known as the plasma membrane or plasmalemma) is a biological membrane that separates the cell contents from the outside environment. A cell membrane is composed of a phospholipid bilayer and proteins that function to protect cellular DNA and mediate the exchange of ions and molecules. The Cell: Cell Membrane
  • Water flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure: from less concentrated to more concentrated solution

Osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia, osmolality Osmolality Plasma osmolality refers to the combined concentration of all solutes in the blood. Renal Sodium and Water Regulation, and tonicity Tonicity Plasma tonicity refers to the concentration of only the osmotically active solutes in blood Renal Sodium and Water Regulation

• Osmosis Osmosis Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane. Body Fluid Compartments:
  • Spontaneous movement of water across a semipermeable membrane Semipermeable membrane Peritoneal Dialysis and Hemodialysis 
  • Water moves from a region of ↓ solute concentration → a region of ↑ solute concentration
  • Tends to equalize the solute concentrations on either side of the membrane
• Osmotic pressure: Hydrostatic pressure Hydrostatic pressure The pressure due to the weight of fluid. Edema is necessary to counteract the process of osmosis Osmosis Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane. Body Fluid Compartments.
• Osmolality Osmolality Plasma osmolality refers to the combined concentration of all solutes in the blood. Renal Sodium and Water Regulation and osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia:
  • Osmolar concentration of a solution
  • In medicine, osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia and osmolality Osmolality Plasma osmolality refers to the combined concentration of all solutes in the blood. Renal Sodium and Water Regulation can be used interchangeably:
    • Not necessarily the same as tonicity Tonicity Plasma tonicity refers to the concentration of only the osmotically active solutes in blood Renal Sodium and Water Regulation 
    • Normal range: 275–295 mOsm/kg
  • 80% of the total osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia of IF and plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products is due to Na and Cl ions. 
  • ½ of the total osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia of ICF ICF The fluid inside cells. Body Fluid Compartments is due to K ions; the remainder is due to other intracellular substances.
• Osmotic gradient: the difference in the osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia of 2 solutions on either side of a semipermeable membrane Semipermeable membrane Peritoneal Dialysis and Hemodialysis
• Tonicity Tonicity Plasma tonicity refers to the concentration of only the osmotically active solutes in blood Renal Sodium and Water Regulation:
  • The measurement of the effective osmotic gradient between 2 fluids separated by a semipermeable membrane Semipermeable membrane Peritoneal Dialysis and Hemodialysis
  • Only accounts for osmotically active Osmotically Active Osmotic Diuretics solutes (cannot cross a semipermeable membrane Semipermeable membrane Peritoneal Dialysis and Hemodialysis)
  • Glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance is osmotically active Osmotically Active Osmotic Diuretics, but the effect is temporary:
    • Glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance is quickly metabolized within the cell → removes the osmotic activity
    • The net result is the addition of solute-free water.
    • The temporary glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance osmoles are not factored into the solution’s net tonicity Tonicity Plasma tonicity refers to the concentration of only the osmotically active solutes in blood Renal Sodium and Water Regulation.
  • Examples of dyssynchrony between osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia/ osmolality Osmolality Plasma osmolality refers to the combined concentration of all solutes in the blood. Renal Sodium and Water Regulation and tonicity Tonicity Plasma tonicity refers to the concentration of only the osmotically active solutes in blood Renal Sodium and Water Regulation:
    • 5% dextrose in water: iso-osmolar but hypotonic Hypotonic Solutions that have a lesser osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation
    • 5% dextrose-0.9% NaCl: hyperosmolar but isotonic Isotonic Solutions having the same osmotic pressure as blood serum, or another solution with which they are compared. Renal Sodium and Water Regulation 
    • 5% dextrose-0.45% NaCl: hyperosmolar but hypotonic Hypotonic Solutions that have a lesser osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation

Crystalloid Fluids

• Most commonly used IVF IVF An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro. Infertility in a hospital setting
• Consist of aqueous electrolyte solutions
• Do not readily cross plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products membranes, but do cross capillary membranes 
• Remain only in the ECF and do not distribute into the ICF ICF The fluid inside cells. Body Fluid Compartments
• Within the ECF, the distribution is ¼ into the intravascular volume and ¾ into the interstitial space.

Normal saline (0.9% NaCl)

• Osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia approximates normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products (275–295 mmol/L):
  • 0.9% = 9 g NaCl in 1,000 g H₂O (equals 1 L of H₂O)
  • 154 mmol/L Na + 154 mmol/L Cl = 308 mmol/L in total 
• Isotonic-to-normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products

Ringer’s lactate (RL)

• Osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia approximates normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products
• Isotonic-to-normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products
• Contains:
  • 130 mmol/L Na
  • 109 mmol/L Cl
  • 4 mmol/L K
  • 3 mmol/L Ca CA Condylomata acuminata are a clinical manifestation of genital HPV infection. Condylomata acuminata are described as raised, pearly, flesh-colored, papular, cauliflower-like lesions seen in the anogenital region that may cause itching, pain, or bleeding. Condylomata Acuminata (Genital Warts)²
  • 28 mmol/L lactate
• Distributes throughout fluid compartments like normal saline

Plasma-Lyte^© (PL)

• Osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia approximates normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products
• Isotonic-to-normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products
• Contains:
  • 140 mmol/L Na
  • 98 mmol/L Cl
  • 5 mmol/L K
  • 3 mmol/L Mg
  • 23 mmol/L gluconate 
  • 27 mmol/L acetate
• Distributes throughout fluid compartments like normal saline

Half-normal saline (0.45% NaCl)

• Osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia is approximately ½ of normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products:
  • 0.45% = 4.5 g NaCl in 1,000 g H₂O
  • 77 mmol/L Na + 77 mmol/L Cl = 154 mmol/L in total
• Hypotonic Hypotonic Solutions that have a lesser osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation to plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products
• Example: 1 L 0.45% NaCl:
  • Equal to 500 mL solute-free water + 500 mL 0.9% NaCl
  • 500 mL 0.9% NaCl remains only in the ECF:
    • 125 mL (¼) into intravascular volume 
    • 375 mL (¾) into interstitial space
  • 500 mL solute-free water distributes throughout the TBW TBW Body Fluid Compartments ( ICF ICF The fluid inside cells. Body Fluid Compartments + ECF):
    • 333 mL (⅔) into the ICF ICF The fluid inside cells. Body Fluid Compartments
    • 167 mL (⅓) into the ECF (42 mL into intravascular space + 125 mL into interstitial space)
  • Combined: only 167 mL into the intravascular space

Quarter-normal saline (0.225% NaCl)

• Osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia is approximately ¼ of normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products:
  • 0.225% = 2.25 g NaCl in 1,000 g H₂O 
  • 38.5 mmol/L Na + 38.5 mmol/L Cl = 77 mmol/L in total 
• Hypotonic Hypotonic Solutions that have a lesser osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation to plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products
• Example: 1 L 0.225% NaCl infused:
  • Equal to 750 mL solute-free water + 250 mL 0.9% NaCl
  • 250 mL 0.9% NaCl remains only in the ECF:
    • 62.5 mL (¼) into intravascular volume
    • 187.5 mL (¾) into interstitial space
  • 750 mL solute-free water distributes throughout the TBW TBW Body Fluid Compartments ( ICF ICF The fluid inside cells. Body Fluid Compartments + ECF):
    • 500 mL (⅔) into the ICF ICF The fluid inside cells. Body Fluid Compartments
    • 250 mL (⅓) into the ECF (62.5 mL into intravascular volume + 187.5 mL into interstitial space)
  • Combined: only 125 mL into the intravascular space

5% dextrose in water

• Osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia approximates normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products: 50 g dextrose in 1 L H₂0 = 252 mmol/L
• Hypotonic Hypotonic Solutions that have a lesser osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation to plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products 
• Dextrose is necessary to prevent hemolysis:
  • Extremely hypotonic Hypotonic Solutions that have a lesser osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation fluids (pure water) cannot be given safely by IV.
  • If pure water is given by IV, water will shift very quickly into cells → hemolysis
  • Dextrose adds enough solutes to slow down water shifts → prevents hemolysis
  • Dextrose is only osmotically active Osmotically Active Osmotic Diuretics for a short time after infusion (the effect dissipates because dextrose is rapidly metabolized).
  • Net effect is the addition of solute-free water.
• Example: 1 L 5% dextrose in water infused:
  • Equals 1 L solute-free water
  • Distributes throughout the TBW TBW Body Fluid Compartments ( ICF ICF The fluid inside cells. Body Fluid Compartments + ECF):
    • 667 mL (⅔) in ICF ICF The fluid inside cells. Body Fluid Compartments
    • 333 mL (⅓) in ECF (83 mL into intravascular volume + 250 mL into interstitial space)
  • Only 83 mL of every 1 L of 5% dextrose in water contributes to the intravascular volume.

Combined solutions

• Osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia is > normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products, tonicity Tonicity Plasma tonicity refers to the concentration of only the osmotically active solutes in blood Renal Sodium and Water Regulation is not.
• Example: 5% dextrose-0.9% NaCl = 252 mmol (5% dextrose in water) + 308 mmol (0.9% NaCl) = 560 mmol/L
• Tonicity Tonicity Plasma tonicity refers to the concentration of only the osmotically active solutes in blood Renal Sodium and Water Regulation is not affected because the solutes from the dextrose are metabolized quickly.

Bicarbonate Bicarbonate Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the ph of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity. Electrolytes (HCO3) solutions

• Crystalloid solutions Crystalloid Solutions Isotonic solutions of mineral salts, such as ringer’s lactate and sodium chloride (saline solution), used in fluid therapy to rehydrate blood volume. Sepsis in Children compounded by the hospital pharmacy (include varying amounts of HCO3 and are generally not produced commercially)
• HCO3 ↑ the pH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance of the solution to physiological or supraphysiological levels
• The osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia and tonicity Tonicity Plasma tonicity refers to the concentration of only the osmotically active solutes in blood Renal Sodium and Water Regulation of the resulting solutions can be adjusted depending on the combination of the starting fluid (usually 5% dextrose in water or 0.45% NaCl) and the amount of added HCO3.
• Example: isotonic Isotonic Solutions having the same osmotic pressure as blood serum, or another solution with which they are compared. Renal Sodium and Water Regulation HCO3:
  • 3 ampules NaHCO3 in 1 L 5% dextrose in water
  • 3 ampules NaHCO3 = 150 mmol Na + 150 mmol HCO3 = 300 mmol/L

3% hypertonic saline Hypertonic saline Hypertonic sodium chloride solution. A solution having an osmotic pressure greater than that of physiologic salt solution (0. 9 g NaCl in 100 ml purified water). Hyponatremia (3% NaCl)

• Osmolarity Osmolarity The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. Hypernatremia and tonicity Tonicity Plasma tonicity refers to the concentration of only the osmotically active solutes in blood Renal Sodium and Water Regulation are significantly ↑ than normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products:
  • 3% NaCl = 30 g NaCl + 1,000 g H₂O
  • 513 mmol Na + 513 mmol Cl = 1026 mmol/L in total
• Example: 1 L 3% NaCl infused:
  • Solute load is equivalent to 3.33 L of 0.9% NaCl (3%/0.9%).
  • Hypertonicity Hypertonicity Volume Depletion and Dehydration results in the mobilization of approximately 2.33 L of solute-free water from the ICF ICF The fluid inside cells. Body Fluid Compartments to the ECF (through osmotic shifts) and 1 L of fluid infused into the ECF as 3% NaCl:
    • ¼ into intravascular volume = 832.5 mL
    • ¾ into interstitial space = 2,500 mL

Overview of composition of common crystalloid solutions Crystalloid Solutions Isotonic solutions of mineral salts, such as ringer’s lactate and sodium chloride (saline solution), used in fluid therapy to rehydrate blood volume. Sepsis in Children

Colloid Fluids

• Colloid solutions include large proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis or cells.
• Do not readily cross capillary membranes
• Remain in the ECF and do not distribute into the ICF ICF The fluid inside cells. Body Fluid Compartments (similar to crystalloids)
• Unlike crystalloids, colloids do not distribute throughout the ECF:
  • Remain within the intravascular space
  • Do not distribute into the interstitial space 
• Blood products are also examples of colloid solutions.

Albumin Albumin Serum albumin from humans. It is an essential carrier of both endogenous substances, such as fatty acids and bilirubin, and of xenobiotics in the blood. Liver Function Tests

• A naturally occurring colloid and the most abundant protein in plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products
• Responsible for 80% of plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products oncotic pressure Oncotic Pressure Edema
• ↑ Plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products oncotic pressure Oncotic Pressure Edema → osmotic shift of fluid from the interstitial space into the intravascular volume
• Duration of volume expansion effect is 12–24 hours.
• Albumin Albumin Serum albumin from humans. It is an essential carrier of both endogenous substances, such as fatty acids and bilirubin, and of xenobiotics in the blood. Liver Function Tests is the only commonly used colloid in clinical practice:
  • Primarily used for specific indications rather than volume expansion
  • More expensive than crystalloids and without commensurate benefit

Synthetic colloids

• Hydroxyethyl starches, dextrans, and gelatins
• Developed for use as volume expanders due to the hypothetical benefit of remaining within the intravascular volume 
• Not commonly used in practice:
  • Colloid solutions are not clinically superior to crystalloid solutions Crystalloid Solutions Isotonic solutions of mineral salts, such as ringer’s lactate and sodium chloride (saline solution), used in fluid therapy to rehydrate blood volume. Sepsis in Children for volume expansion (despite remaining exclusively in the intravascular space).
  • Expensive
  • Hydroxyethyl starches have been associated with acute kidney injury Acute Kidney Injury Acute kidney injury refers to sudden and often reversible loss of renal function, which develops over days or weeks. Azotemia refers to elevated levels of nitrogen-containing substances in the blood that accompany AKI, which include BUN and creatinine. Acute Kidney Injury.
  • Unlike albumin Albumin Serum albumin from humans. It is an essential carrier of both endogenous substances, such as fatty acids and bilirubin, and of xenobiotics in the blood. Liver Function Tests, synthetic colloids do not have any other specific indications for use.

Comparison of crystalloids and colloids

Indications

Intravascular volume expansion

• Isotonic Isotonic Solutions having the same osmotic pressure as blood serum, or another solution with which they are compared. Renal Sodium and Water Regulation crystalloid fluids:
  • Preferred IVF IVF An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro. Infertility for volume expansion
  • RL and PL are considered “balanced” solutions:
    • Approximate the pH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance and electrolyte composition of normal plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products more closely than 0.9% NaCl
    • Avoid hyperchloremic metabolic acidosis Hyperchloremic Metabolic Acidosis Potassium-sparing Diuretics associated with 0.9% NaCl 
    • Normal saline or RL are preferred to PL due to cost.
• Colloid fluids:
  • Not a 1st-line therapy for volume expansion
  • Sometimes used in a hypervolemic state with ↓ effective arterial blood volume Effective arterial blood volume Renal Sodium and Water Regulation
• Blood products: only used for volume expansion in specific circumstances:
  • Packed RBCs Packed RBCs Transfusion Products: acute bleeding or severe anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types
  • Platelets Platelets Platelets are small cell fragments involved in hemostasis. Thrombopoiesis takes place primarily in the bone marrow through a series of cell differentiation and is influenced by several cytokines. Platelets are formed after fragmentation of the megakaryocyte cytoplasm. Platelets: Histology: bleeding related to ↓ platelet count or platelet dysfunction
  • Fresh frozen plasma Fresh Frozen Plasma Transfusion Products: bleeding related to coagulation factor deficiency

Maintenance fluid

• Maintenance fluids may be indicated for individuals unable to take nutrition by mouth.
• Most commonly a crystalloid fluid with or without added dextrose, bicarbonate Bicarbonate Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the ph of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity. Electrolytes, and/or potassium Potassium An element in the alkali group of metals with an atomic symbol k, atomic number 19, and atomic weight 39. 10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the water-electrolyte balance. Hyperkalemia
• Goal: approximate the content of lost fluid and replace the fluid at a rate similar to the loss
• Normal daily maintenance dose Maintenance Dose Dosage Calculation:
  • Adults: 1,500 mL + 20 mL/kg for every kg above 20 kg
  • Neonates: 150 mL/kg
• Conditions altering the amount of maintenance fluids:
  • ↑ Maintenance fluids: fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever and tachypnea Tachypnea Increased respiratory rate. Pulmonary Examination
  • ↓ Maintenance fluids: congestive cardiac failure Cardiac failure Congestive heart failure refers to the inability of the heart to supply the body with normal cardiac output to meet metabolic needs. Echocardiography can confirm the diagnosis and give information about the ejection fraction. Heart Failure and low-output renal failure Renal failure Conditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate. Crush Syndrome

Specific sodium Sodium A member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23. Hyponatremia disorders

• Hypernatremia Hypernatremia Hypernatremia is an elevated serum sodium concentration > 145 mmol/L. Serum sodium is the greatest contributor to plasma osmolality, which is very tightly controlled by the hypothalamus via the thirst mechanism and antidiuretic hormone (ADH) release. Hypernatremia occurs either from a lack of access to water or an excessive intake of sodium. Hypernatremia:
  • Hypotonic Hypotonic Solutions that have a lesser osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation fluids (usually 5% dextrose in water or 0.45% NaCl) are given to replace the free water deficit.
  • The rate of fluid should be adjusted to target a gradual ↓ in chronic hypernatremia Hypernatremia Hypernatremia is an elevated serum sodium concentration > 145 mmol/L. Serum sodium is the greatest contributor to plasma osmolality, which is very tightly controlled by the hypothalamus via the thirst mechanism and antidiuretic hormone (ADH) release. Hypernatremia occurs either from a lack of access to water or an excessive intake of sodium. Hypernatremia.
  • Overly rapid correction of hypernatremia Hypernatremia Hypernatremia is an elevated serum sodium concentration > 145 mmol/L. Serum sodium is the greatest contributor to plasma osmolality, which is very tightly controlled by the hypothalamus via the thirst mechanism and antidiuretic hormone (ADH) release. Hypernatremia occurs either from a lack of access to water or an excessive intake of sodium. Hypernatremia can cause cerebral edema Cerebral edema Increased intracellular or extracellular fluid in brain tissue. Cytotoxic brain edema (swelling due to increased intracellular fluid) is indicative of a disturbance in cell metabolism, and is commonly associated with hypoxic or ischemic injuries. An increase in extracellular fluid may be caused by increased brain capillary permeability (vasogenic edema), an osmotic gradient, local blockages in interstitial fluid pathways, or by obstruction of CSF flow (e.g., obstructive hydrocephalus). Increased Intracranial Pressure (ICP).
• Hyponatremia Hyponatremia Hyponatremia is defined as a decreased serum sodium (sNa+) concentration less than 135 mmol/L. Serum sodium is the greatest contributor to plasma osmolality, which is very tightly controlled via antidiuretic hormone (ADH) release from the hypothalamus and by the thirst mechanism. Hyponatremia:
  • Isotonic Isotonic Solutions having the same osmotic pressure as blood serum, or another solution with which they are compared. Renal Sodium and Water Regulation fluids (usually 0.9% NaCl) may be given for mild-to-moderate cases.
  • Hypertonic Hypertonic Solutions that have a greater osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation fluids (usually 3% NaCl) are indicated for severe cases, especially with neurologic symptoms. 
  • Overly rapid correction of hyponatremia Hyponatremia Hyponatremia is defined as a decreased serum sodium (sNa+) concentration less than 135 mmol/L. Serum sodium is the greatest contributor to plasma osmolality, which is very tightly controlled via antidiuretic hormone (ADH) release from the hypothalamus and by the thirst mechanism. Hyponatremia can result in osmotic demyelination Demyelination Multiple Sclerosis syndrome.

Cerebral edema Cerebral edema Increased intracellular or extracellular fluid in brain tissue. Cytotoxic brain edema (swelling due to increased intracellular fluid) is indicative of a disturbance in cell metabolism, and is commonly associated with hypoxic or ischemic injuries. An increase in extracellular fluid may be caused by increased brain capillary permeability (vasogenic edema), an osmotic gradient, local blockages in interstitial fluid pathways, or by obstruction of CSF flow (e.g., obstructive hydrocephalus). Increased Intracranial Pressure (ICP)

• Hypertonic Hypertonic Solutions that have a greater osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation fluids (usually hypertonic saline Hypertonic saline Hypertonic sodium chloride solution. A solution having an osmotic pressure greater than that of physiologic salt solution (0. 9 g NaCl in 100 ml purified water). Hyponatremia) may be used to induce hypernatremia Hypernatremia Hypernatremia is an elevated serum sodium concentration > 145 mmol/L. Serum sodium is the greatest contributor to plasma osmolality, which is very tightly controlled by the hypothalamus via the thirst mechanism and antidiuretic hormone (ADH) release. Hypernatremia occurs either from a lack of access to water or an excessive intake of sodium. Hypernatremia.
• The result is the movement of water out of cells → ↓ intracranial pressure Intracranial Pressure Idiopathic Intracranial Hypertension

Bicarbonate Bicarbonate Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the ph of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity. Electrolytes (HCO3) solutions

HCO3 may be indicated for:

• Severe acidemia Acidemia Respiratory Acidosis ( pH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance < 7.2)
• Urinary alkalinization (e.g., tricyclic antidepressant Antidepressant Antidepressants encompass several drug classes and are used to treat individuals with depression, anxiety, and psychiatric conditions, as well as those with chronic pain and symptoms of menopause. Antidepressants include selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and many other drugs in a class of their own. Serotonin Reuptake Inhibitors and Similar Antidepressants poisoning or certain chemotherapies)
• Methanol Methanol A colorless, flammable liquid used in the manufacture of formaldehyde and acetic acid, in chemical synthesis, antifreeze, and as a solvent. Ingestion of methanol is toxic and may cause blindness. Metabolic Acidosis or ethylene glycol poisoning Ethylene glycol poisoning Alcohol Use Disorder

Nutrition

• For individuals allowed nil per os
• Partial parenteral nutrition Parenteral nutrition The administering of nutrients for assimilation and utilization by a patient who cannot maintain adequate nutrition by enteral feeding alone. Nutrients are administered by a route other than the alimentary canal (e.g., intravenously, subcutaneously). Central Venous Catheter (PPN):
  • Protein only
  • Can be given via peripheral or central line
  • For individuals allowed nil per os for a short duration of time (2–3 days).
• Total parenteral nutrition Parenteral nutrition The administering of nutrients for assimilation and utilization by a patient who cannot maintain adequate nutrition by enteral feeding alone. Nutrients are administered by a route other than the alimentary canal (e.g., intravenously, subcutaneously). Central Venous Catheter (TPN):
  • Complete nutrition: carbohydrates Carbohydrates A class of organic compounds composed of carbon, hydrogen, and oxygen in a ratio of cn(H2O)n. The largest class of organic compounds, including starch; glycogen; cellulose; polysaccharides; and simple monosaccharides. Basics of Carbohydrates, proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis, and fats Fats The glyceryl esters of a fatty acid, or of a mixture of fatty acids. They are generally odorless, colorless, and tasteless if pure, but they may be flavored according to origin. Fats are insoluble in water, soluble in most organic solvents. They occur in animal and vegetable tissue and are generally obtained by boiling or by extraction under pressure. They are important in the diet (dietary fats) as a source of energy. Energy Homeostasis
  • Given via central line
  • For individuals allowed nil per os for a long duration of time.
  • ↑ Risk of infection due to bacteremia Bacteremia The presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion. Glycopeptides or fungemia Fungemia The presence of fungi circulating in the blood. Opportunistic fungal sepsis is seen most often in immunosuppressed patients with severe neutropenia or in postoperative patients with intravenous catheters and usually follows prolonged antibiotic therapy. Chronic Granulomatous Disease

Albumin Albumin Serum albumin from humans. It is an essential carrier of both endogenous substances, such as fatty acids and bilirubin, and of xenobiotics in the blood. Liver Function Tests

Albumin Albumin Serum albumin from humans. It is an essential carrier of both endogenous substances, such as fatty acids and bilirubin, and of xenobiotics in the blood. Liver Function Tests is used for specific purposes:

• Volume expansion in hypervolemic states with ↓ effective arterial blood volume Effective arterial blood volume Renal Sodium and Water Regulation (i.e., hypoalbuminemia Hypoalbuminemia A condition in which albumin level in blood (serum albumin) is below the normal range. Hypoalbuminemia may be due to decreased hepatic albumin synthesis, increased albumin catabolism, altered albumin distribution, or albumin loss through the urine (albuminuria). Nephrotic Syndrome in Children cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis)
• Treatment of hepatorenal syndrome Hepatorenal Syndrome Hepatorenal syndrome (HRS) is a potentially reversible cause of acute kidney injury that develops secondary to liver disease. The main cause of HRS is hypovolemia, often as a result of forced diuresis or drainage of ascites. This leads to renal vasoconstriction resulting in hypoperfusion of the kidneys. Hepatorenal Syndrome
• Treatment of acute kidney injury Acute Kidney Injury Acute kidney injury refers to sudden and often reversible loss of renal function, which develops over days or weeks. Azotemia refers to elevated levels of nitrogen-containing substances in the blood that accompany AKI, which include BUN and creatinine. Acute Kidney Injury related to spontaneous bacterial peritonitis Spontaneous Bacterial Peritonitis Ascites
• Prevention of acute kidney injury Acute Kidney Injury Acute kidney injury refers to sudden and often reversible loss of renal function, which develops over days or weeks. Azotemia refers to elevated levels of nitrogen-containing substances in the blood that accompany AKI, which include BUN and creatinine. Acute Kidney Injury related to large volume paracentesis Paracentesis A procedure in which fluid is withdrawn from a body cavity or organ via a trocar and cannula, needle, or other hollow instrument. Portal Hypertension
• Treatment of refractory edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema (added to loop diuretics Diuretics Agents that promote the excretion of urine through their effects on kidney function. Heart Failure and Angina Medication)
• Exchange fluid for plasmapheresis Plasmapheresis Procedure whereby plasma is separated and extracted from anticoagulated whole blood and the red cells retransfused to the donor. Plasmapheresis is also employed for therapeutic use. Stevens-Johnson Syndrome
• Management of severe burns Burns A burn is a type of injury to the skin and deeper tissues caused by exposure to heat, electricity, chemicals, friction, or radiation. Burns are classified according to their depth as superficial (1st-degree), partial-thickness (2nd-degree), full-thickness (3rd-degree), and 4th-degree burns. Burns

Adverse Effects

Frequently reassess goals of IVF IVF An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro. Infertility therapy and tailor management to avoid adverse effects:

Volume overload

• Risk factors:
  • Large volumes of administered fluid
  • Underlying cardiac issues
  • Hepatic impairment
  • Renal dysfunction
• Clinical presentation:
  • Weight gain
  • Pitting edema Pitting edema Edema caused by excess fluid without excess colloid. Leaves “pits” due to fluid displacement when pressure is applied to the area Edema
  • Body cavity effusions:
    • Ascites Ascites Ascites is the pathologic accumulation of fluid within the peritoneal cavity that occurs due to an osmotic and/or hydrostatic pressure imbalance secondary to portal hypertension (cirrhosis, heart failure) or non-portal hypertension (hypoalbuminemia, malignancy, infection). Ascites
    • Pleural effusions
  • Respiratory distress
  • Worsening supplemental oxygen Supplemental Oxygen Respiratory Failure requirement
• Diagnosis:
  • Serial body weights
  • Chest X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests
  • Serum BNP BNP A peptide that is secreted by the brain and the heart atria, stored mainly in cardiac ventricular myocardium. It can cause natriuresis; diuresis; vasodilation; and inhibits secretion of renin and aldosterone. It improves heart function. It contains 32 amino acids. Renal Sodium and Water Regulation level
• Management:
  • Discontinue or ↓ IVF IVF An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro. Infertility.
  • Loop diuretics Diuretics Agents that promote the excretion of urine through their effects on kidney function. Heart Failure and Angina Medication
  • Dialysis Dialysis Renal replacement therapy refers to dialysis and/or kidney transplantation. Dialysis is a procedure by which toxins and excess water are removed from the circulation. Hemodialysis and peritoneal dialysis (PD) are the two types of dialysis, and their primary difference is the location of the filtration process (external to the body in hemodialysis versus inside the body for PD). Peritoneal Dialysis and Hemodialysis (if severe or unresponsive to diuretics Diuretics Agents that promote the excretion of urine through their effects on kidney function. Heart Failure and Angina Medication)

Metabolic abnormalities

Acid-base abnormalities:

• Hyperchloremic metabolic acidosis Hyperchloremic Metabolic Acidosis Potassium-sparing Diuretics:
  • Nonanion gap metabolic acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis caused by infusion of large amounts of chloride-rich fluids (e.g., normal saline)
  • May cause worse clinical outcomes (conflicting studies)
  • Diagnosed by:
    • ↑ Serum Cl
    • ↓ Serum HCO3
    • ↓ Serum pH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance
    • Normal serum anion gap Anion gap Metabolic Acidosis
  • Management includes:
    • ↓ Chloride-rich IVF IVF An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro. Infertility 
    • Switching to balanced crystalloid solutions Crystalloid Solutions Isotonic solutions of mineral salts, such as ringer’s lactate and sodium chloride (saline solution), used in fluid therapy to rehydrate blood volume. Sepsis in Children (e.g., PL or RL)
• Metabolic alkalosis Alkalosis A pathological condition that removes acid or adds base to the body fluids. Respiratory Alkalosis:
  • Serum HCO3 and serum pH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance should be frequently monitored when administering any IVF IVF An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro. Infertility containing HCO3.
  • Management:
    • Discontinue or ↓ HCO3 solutions.
    • Give 0.9% NaCl to ↓ the pH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance (induces a slightly hyperchloremic metabolic acidosis Hyperchloremic Metabolic Acidosis Potassium-sparing Diuretics).
• High anion gap Anion gap Metabolic Acidosis metabolic acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis:
  • May occur if RL or PL is given in the setting of hepatic insufficiency
  • Adequate liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy function: needed to metabolize the lactate, gluconate, and/or acetate into HCO3
  • Management: Discontinue RL or PL.

Hypernatremia Hypernatremia Hypernatremia is an elevated serum sodium concentration > 145 mmol/L. Serum sodium is the greatest contributor to plasma osmolality, which is very tightly controlled by the hypothalamus via the thirst mechanism and antidiuretic hormone (ADH) release. Hypernatremia occurs either from a lack of access to water or an excessive intake of sodium. Hypernatremia can result from:

• Large volumes of 0.9% NaCl 
• Relatively small volumes of 3% NaCl

Hyponatremia Hyponatremia Hyponatremia is defined as a decreased serum sodium (sNa+) concentration less than 135 mmol/L. Serum sodium is the greatest contributor to plasma osmolality, which is very tightly controlled via antidiuretic hormone (ADH) release from the hypothalamus and by the thirst mechanism. Hyponatremia:

• Can occur from administration of any hypotonic Hypotonic Solutions that have a lesser osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation fluid, depending on:
  • Volume given 
  • Individual’s initial TBW TBW Body Fluid Compartments
• Commonly occurs with hypotonic Hypotonic Solutions that have a lesser osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid. Renal Sodium and Water Regulation fluids administered for long periods of time

Hyperkalemia Hyperkalemia Hyperkalemia is defined as a serum potassium (K+) concentration >5.2 mEq/L. Homeostatic mechanisms maintain the serum K+ concentration between 3.5 and 5.2 mEq/L, despite marked variation in dietary intake. Hyperkalemia can be due to a variety of causes, which include transcellular shifts, tissue breakdown, inadequate renal excretion, and drugs. Hyperkalemia:

• RL and PL contain added K
• May occur if large volumes of RL or PL are given in the setting of renal dysfunction
• May occur if large volumes of packed red blood cells Red blood cells Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology are given

Hyperglycemia Hyperglycemia Abnormally high blood glucose level. Diabetes Mellitus:

• May occur with dextrose-containing solutions 
• The rate of IVF IVF An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro. Infertility overwhelms the body’s capacity to metabolize the IVF IVF An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro. Infertility‘s dextrose load.
• More likely to occur in diabetic individuals, but can also occur in nondiabetic individuals