clinical signs/symptoms of mild volume depletion- 5% loss of pre-illness body weight
- decreased skin turgor
- dry mucous membranes
- pale skin color
- diminished urine output
- normal BP
- normal-to-increased heart rate
- flat fontanelle
- consolableclinical signs/symptoms of moderate volume depletion- 10% loss of pre-illness body weight
- tenting skin
- very dry mucous membranes
- grey skin color
- severely decreased urine output
- normal-to-slightly decreased blood pressure
- increased heart rate
- soft fontanelle
- irritableclinical signs/symptoms of severe volume depletion- 15% loss of pre-illness body weight
- tenting skin
- parched mucous membranes
- mottled skin color
- azotemic urine output
- decreased blood pressure
- significantly increased heart rate
- sunken fontanelle
- lethargic/comatoseWhat are crystalloids?- salt- and sugar-containing solutions
- rapid fluid volume replacement
- easily stored and readily available
- inexpensive
- distributes out of intravascular space within 2 hours
- two- to four-times more crystalloid is needed than colloids
- peripheral edema if >10 L in 24 hoursWhat are isotonic solutions?- the osmolarity is the same as body fluids
- no osmotic drive to leave or enter intracellular space
- 100% extracellular (3/4 interstitial and 1/4 intravascular)
- less than 20% of infused fluids remain intravascular after 2 hours
- e.g., LR, 0.9%NSDescribe Lactated Ringers solution.- osmolarity of 273 mOsm/L
- does not increase blood lactate levels (lactate is converted to bicarbonate by the liver)
ADRs:
- hyponatremia
- hyperkalemia
- concurrent blood transfusions (potential binding of calcium with citrate in blood products)
Contains (mEq/L):
- 130 Na⁺
- 109 Cl⁻
- 4 K⁺
- 3 Ca²⁺
- 28 HCO₃⁻Describe normal saline.- osmolarity of 308 mOsm/L
- equal distribution to intravascular and interstitial fluids
- contains 154 mEq/L Na⁺ and 154 mEq/L Cl⁻
ADRs:
- hyperchloremic metabolic acidosis
- fluid overloadDescribe hypotonic solutions.- depending on the osmolarity, fluid will move to intracellular space
Examples:
- 0.45%NS (composed of 77 Na⁺ and Cl⁻; 500 mL of 0.9%NS and 500 mL of water)
- 0.225%NS (composed of 37.5 Na⁺ and Cl⁻; 250 mL of 0.9%NS and 750 mL of water)Describe D5W.- hypotonic solution (252 mOsm/L)
- dextrose rapidly taken up by cells
- can cause hyponatremia
- indicated for uncomplicated dehydration or water deprivation
- large intracellular distribution
- no role in volume resuscitationDescribe 0.45%NS/D5W- indicated for fluid maintenance in euvolemic or mildly dehydrated patients
- not indicated for volume resuscitation
- intracellular and interstitial expansion (77 mEq/L; equivalent to 500 mL free water and 500 mL NS)
- 1/3 ICF; 2/3 ECF
- most common pre-mixed hospital maintenance fluidDescribe hypertonic solutions.- indicated for severe volume depletion
- fluid redistribution from intracellular to intravascular compartment
- phlebitis and tissue necrosisDescribe 3%NS.- composed of 513 mEq Na⁺ and Cl⁻
- 1027 mOsm/L
- rapid expansion of intravascular compartment
- 1L 3%NS → ECF only
ADRs:
- hypernatremia
- hyperchloremic metabolic acidosis
- intracellular volume depletionadvantages/disadvantages of crystalloidsAdvantages:
- cheap
- long shelf-life
- no infectious risk
- not antigenic/allergenic
Disadvantages:
- effects not as long-lasting as colloids (2 hours vs. days)
- 2 to 4 times more crystalloid is needed that colloidsWhat are colloids?- proteins or polysaccharides with minimal permeability through intravascular space
- larger molecular weight molecules remain in intravascular space longer
- indicated in conjunction with or as a replacement for crystalloids
- hyperoncotic solutions pull water into the intravascular space
- expensive (>$50)protein colloid solutions- albumin 5% or 25%
- plasmanate
- whole blood
- PRBCs
- FFP
- cryoprecipitatenon-protein colloid solutions- hetastarch 6%
- pentastarch
- dextran 40
- dextran 70Describe 5% albumin.- isotonic (154 mEq/L)
- isooncotic with serum
- 3-4 times more potent than LR
- volume expansion
- redistributes to interstitial space
- 10% leaves vascular space in 2 hours
- effects last 24-36 hoursDescribe 25% albumin.- isotonic (140 ± 15 mEq/L)
- hyperoncotic
- used in hypovolemia with edema
- 1000 mL can pull 350 mL of fluid from intracellular to intravascular space
- swollen and hypovolemicADRs of albumin 5% and 25%- minimal risk of viral hepatitis
- intravascular volume overload (avoid infusion rate >10 mL/min)
- intracellular volume depletion with 25%
- allergic reactions (fever, chills, urticaria, tachycardia, hypotension, vasodilation)
- only good for four hours once spikedDescribe hetastarch 6% (Hespan).- synthetic polymers derived from amylopectin
- heterogenous mixture
- average MW 69,000 (10,000 - 1 million)
- less costly alternative to albumin
- similar IV volume expansion to 5% albumin
- slightly hypertonic (310 mOsm/L)
- only good for 4 hrs once spiked
- eliminated by the kidneys and RES
- half-life changes over time
- dosing: 500-1000 mL (max 1500 mL or 20 mL/kg/day)
ADRs:
- elevation of serum amylase
- elevation of indirect bilirubin
- anaphylactoid reactions (rare)
- intravascular volume overload
- dose-related anticoagulationDescribe the dextrans (40, 70).- mixture of glucose polymers
- variable molecular weight
- indicated for plasma volume expansion
- improves microvascular circulation by decreasing blood viscosity
- coats vascular endothelial cells (minimizes platelet and RBC adhesion/aggregation)
ADRs:
- dose-related bleeding, thrombocytopenia
- anaphylaxis (1% - 5%)
- risk for acute renal failureDescribe the percentages contained in each fluid compartment.- TBW is composed of intracellular fluid (ICF) and extracellular fluid (ECF)
- ICF has 2/3 of TBW
- ECF has 1/3 of TBW
- ECF is also composed of both interstitial fluid (3/4 ECF) and intravascular fluid (1/4 ECF)
