Fluids, electrolytes, and acid-base therapy Flashcards
Fluids in the body are distributed in two compartments: the _________ volume and the __________ volume.
intracellular fluid (ICF); extracellular fluid (ECF)
What are the four types of extracellular fluids?
The ECF is composed of interstitial fluid, plasma, lymph, and transcellular fluids (such as synovial, pleural, abdominal, and cerebrospinal fluids).
T/F: The normal volume of gastrointestinal secretion in horses is approximately 100 L every 24 hours in a 500-kg horse.
True
T/F: The normal volume of gastrointestinal secretion in horses is approximately equivalent to the intracellular fluid volume.
False; The normal volume of gastrointestinal secretion in horses is approximately equivalent to the extracellular fluid volume, representing about 100 L every 24 hours in a 500-kg horse.
T/F: The volume of total body water (TBW) represents 55% of body weight in adults and up to 60% in neonates.
False; The volume of total body water (TBW) represents 60% of body weight in adults and up to 80% in neonates.
The ECF volume represents ____ of total body water (TBW) or ___ of body weight (in adults) to ___ of TBW or ____ of body weight (in neonates) of water.
1/3; 20%; 1/2; 40%
The ICF volume represents approximately ____ of total body water (TBW) or ____ of body weight.
2/3; 40%
T/F: In neonates, the ECF is approximately 25% of the TBW, and it decreases to approximately 15% by 24 weeks of age.
False; In neonates, the ECF is approximately 40% of the TBW, and it decreases to approximately 30% by 24 weeks of age.
You evaluate a horse that has a heart rate 40-60 bpm, CRT = 2 secs, PCV/TP = 40%/7.0 g/dL, and creatinine of 1.5-2 mg/dL. What do you estimate this horses hydration deficit to be?
6%
You evaluate a horse that has a heart rate 61-80 bpm, CRT = 3 secs, PCV/TP = 45%/7.5 g/dL, and creatinine of 2-3 mg/dL. What do you estimate this horses hydration deficit to be?
8%
You evaluate a horse that has a heart rate 81-100 bpm, CRT = 4 secs, PCV/TP = 50%/8.0 g/dL, and creatinine of 3-4 mg/dL. What do you estimate this horses hydration deficit to be?
10%
You evaluate a horse that has a heart rate > 100 bpm, CRT >4 secs, PCV/TP = 50%/ > 8.0 g/dL, and creatinine > 4 mg/dL. What do you estimate this horses hydration deficit to be?
12%
Which of the following requires hepatic metabolism for conversion to bicarbonate?
- acetate
- gluconate
- lactate
- silicate
lactate
hypocalcemia that is refractory to calcium therapy may indicate ____________.
- hypokalemia
- hypochloridemia
- hypomagnesemia
- hyponatremia
hypomagnesemia
T/F: Hetastarch is less effective than plasma in restoring oncotic pressure.
False: Hetastarch is more effective than plasma in restoring oncotic pressure.
T/F: The preferred dose of hetastarch is 5 ml/kg.
False; 10 ml/kg
T/F: Use of a colloid osmometer is indicated to accurately monitor hetastarch therapy.
True
T/F: Hetastarch is more commonly associated with anaphylactic reactions than dextran.
False; Hetastarch is less commonly associated with anaphylactic reactions than dextran.
Blood volume in sedentary horses represents approximately ___ of body weight. In fit horses, this value can reach ____ of body weight. In neonates, blood volume represents ____ of body weight and decreases to adult values by ___________ of age.
8%; 14%; 15%; 12 weeks
What is the main cation in plasma?
What are the main anions in plasma?
In plasma, sodium is the main cation, and bicarbonate and chloride are the main anions.
Proteins contribute to the ________ charges, and they also provide oncotic pressure. _________ or molecules of similar size are the main contributors to oncotic pressure.
negative; Albumin
The __________ ______ accounts for about 75% of the ECF, and it is composed mainly of sodium, bicarbonate, and chloride, but the concentration of protein there is ______ than in plasma.
interstitial fluid; lower
What are the main cations of the intracellular fluid compartment?
What are the main anions of the ICF compartment?
the important ICF cations are potassium and magnesium, and the important ICF anions are phosphates and proteins
Water and ionic solute exchange between the vascular and
interstitial compartments occurs at the capillary level and is rapid; equilibrium is reached within ___ to ___ minutes. The rate of exchange or net filtration that occurs between these compartments is controlled by a balance between the forces that favor filtration (capillary _________ pressure and tissue _______ pressure) and the forces that tend to retain fluid within the vascular space (plasma ________ pressure and tissue _________ pressure).
30 to 60 minutes; hydrostatic; oncotic; oncotic hydrostatic
Exchanges between the extracellular and intracellular compartments are comparatively slow, taking up to 24 hours to reach equilibrium.
T/F: Sodium accounts for most of the osmotically active particles in the ECF.
True; Sodium is the most abundant cation in the ECF. Other osmotically active compounds that make a significant contribution to ECF osmolarity are glucose and urea.
Exchanges between the extracellular and intracellular compartments are comparatively slow, taking up to ___ ______ to reach equilibrium.
24 hours
What is the definition of a buffer?
a buffer is a compound that can accept or donate protons to maintain the pH within a narrow range.
In the body, _________ is the primary buffer system of the extracellular fluid, whereas _____ and inorganic and organic ________ represent the principal intracellular buffers.
bicarbonate; protein; phosphates
The dissociation of carbonic acid is expressed by the law of mass action: what is the equation?
H + HCO <=> H2CO3 <=> CO2 + H2O
In the body, this system is open, and carbonic acid, in the presence of carbonic anhydrase, forms CO2, which is eliminated entirely from the system by alveolar ventilation.
T/F: An acute increase in hydrogen ions from a fixed acid load is immediately buffered by bicarbonate and intracellular buffers.
True; This is the acute physiochemical response. Alveolar ventilation is subsequently modified, and this is complete within hours to further minimize changes in pH by normalizing the ratio of HCO3− to PCO2.