Water, Electrolytes, and Acid-Base Balance Flashcards
result of loss of electrolytes, shifts of
certain electrolytes, or relative changes in concentrations caused by loss of water
electrolyte imbalance
half of the total body concentration of sodium is found in?
the ECF
renal excretion of Na+ is controlled by?
aldosterone
an anion of highest concentration in the ECF
Chloride
responsible for the maintenance of acid-base balance
Bicarbonate
normal blood pH
7.35-7.45 (7.3-7.5)
mixture of a weakly dissociated acid and a salt of that acid
buffer
is of assistance in understanding and explaining pH control of body fluids
Henderson-Hasselbach equation
buffer system most important in the control of blood pH
bicarbonate/carbonic acid buffer systems (HCO3-/H2CO3)
HCO3-/H2CO3 normal plasma ratio
20:1
respiratory center found in the medulla oblongata is sensitive to blood levels of?
pCO2
occurs when loss of body water exceeds intake
Dehydration
Loss of body fluids may occur as a result of?
- diarrhea
- prolonged vomiting
- sequestration of fluid from the digestive tract
- prolonged fever
- sweating
- exudating burns of open wounds
- excessive blood loss and
- uncontrolled polyuria.
During measurement of dehydration in RBC concentration, these values are increased.
PCV, Hgb and TEC
occurs because of excessive Na loss
hyponatremia
used for estimating electrolyte levels in
serum and plasma
Plasma photometry and ion-specific electrodes
Chloride levels are determined by?
mercurimetric
technique and ion specific electrode
Laboratory tests useful in determining acid-base balance
Henderson-Hasselbach equation
Partial Pressure of CO2 is expressed in?
mm.Hg.
level of bicarbonate can be determined directly
by which technique?
tritrimetric technique
Carbonic acid is not directly measured but by multiplying?
pCO2 by 0.03
it is estimated by
subtracting 1.2 from the total carbon dioxide values
Bicarbonate concentration
condition where CO2 elimination is decreased and blood carbonic acid concentration and
pCO2 are increased
Respiratory acid
deficiency of carbonic acid as a consequence of pCO2 loss
Respiratory alkalosis
Respiratory alkalosis may occur with? (3)
- Hyperventilation
- With general anesthesia
- Early heat prostration
proportion of water in an animal’s body
45 to 70%
Proportion of water in an animal’s body is inversely proportional to the body _____content
fat
compartment with 65 to 75% of the total body water
ICF
compartment with 25% of the total body water
ECF
ECF are found in 3 locations
- Intravascularly (plasma)
- Interstitially (including lymph)
- Transcellularly (CSF, Joint fluid, Intestinal contents)
ultrafiltrate of plasma and water and
electrolytes move freely within this compartment
Interstitial fluid
Intravascular fluid has almost the same composition as interstitial fluid
except?
its higher protein level
water taken into the body as liquids and contained in solid
foods
Preformed water
water derived from oxidation of foods to carbon dioxide and
water
water of oxidation
Water of oxidation produces how many ml of water from the metabolism of each 100 calories
12 ml
accounts for slightly more than half the total fluid output of the body
urine
ADH controls water loss through kidney in response to?
plasma osmotic pressure and by aldosterone
occurs when loss of body water exceeds intake
dehydration
Substances that become ionized when placed in water
electrolytes
unit of measurement for electrolytes
milli-equivalents per liter of fluid (mEq/L)
number of grams of solute contained in 1cc of a normal
solution
milliequivalent
most important route for sodium excretion
kidney
Renal reabsorption of sodium requires an equivalent passage of
________ in the opposite direction
hydrogen or potassium ions
In these species, sodium is reabsorbed in the lower intestinal tract
carnivores and most herbivores
These herbivores with large quantities of fluid in the feces have considerable fecal loss of sodium
cow and the horse
Hyponatremia may occur with ______ due to increased sodium excretion to prevent hyperosmolarity
hyperglycemia
True or False. Aldosterone facilitates excretion of potassium.
True. Because it increases sodium reabsorption by promoting the exchange of sodium in tubular fluid for potassium in the tubular cell.
In this condition, potassium moves into the cell in exchange for hydrogen ions
and may cause hypokalemia
alkalosis
In which condition potassium moves out of the cell in exchange for hydrogen ions
and may cause hyperkalemia
acidosis
In every 0.1 unit decrease in blood pH causes plasma potassium to increases about?
0.6 mEq/L
Low concentrations of K+ in the ECF results to?
muscular weakness and ECG abnormalities
High concentration of K+ in the ECF (10-12 mEq/L) result to?
severe myocardial disturbances and death due to cardiac arrest
Chloride concentration is low in ____ and high in ______
ICF, ECF
Unusual reduction in chloride concentration in the absence of comparable change in sodium, usually reflects?
sequestration of gastric juice in the stomach or vomiting
mostly of endogenous origin in that it comes from the hydration of carbon dioxide to carbonic acid
Bicarbonate
Bicarbonate is lost through secretions to?
digestive tract and in the urine
distribution of fluid among the body fluid spaces is determined by
osmotic pressure
determined by the total number of particles (electrolyte ions) dissolved in each of these fluids
osmotic pressure of ICF and ECF
clinical unit of measurement for osmolality
milliosmoles (mOsm) per kilogram of water
normal osmolality of plasma in domestic animals
300 mOsm/kg of
plasma water
True or False. Normal hydration of the body depends only on the optimum water in the body.
False. It also significantly depends on optimum protein, sodium, and potassium in the appropriate fluid
compartments to hold the proper amount of water in each compartment.
single most important buffer system in
the body fluids
bicarbonate/carbonic acid buffer system
useful in understanding pH control of body fluids
Henderson-Hasselbalch equation
pH of plasma is dependent upon the ratio of?
HCO3- to H2CO3
principal body compensatory action of respiratory alkalosis
renal
bicarbonate ion increased due to loss of chloride ion or to excess
ingestion of bicarbonate
metabolic alkalosis
ketone and/or excess chloride ions replace bicarbonate ions
metabolic acidosis
carbonic acid deficit due to hyperactive breathing which results in an increased loss of carbon dioxide from the lungs
respiratory alkalosis
carbonic acid excess due to hypoventilation
respiratory acidosis
- What is the primary consequence of dehydration in farm animals?
a. Increased body fat content
b. Reduction in circulating blood volume
c. Increased water retention in cells
d. Decreased metabolic rate
B
- What condition results from the rapid ingestion of large quantities of water?
a. Dehydration
b. Water intoxication
c. Hyponatremia
d. Hyperkalemia
B
- Which of the following is NOT a cause of dehydration?
a. Diarrhea
b. Excessive blood loss
c. Increased fluid intake
d. Prolonged fever
C
- What is the primary mechanism for the formation of carbonic acid in the body?
A. Direct secretion from gastric glands
B. Combination of carbon dioxide and water in erythrocytes
C. Metabolism of amino acids in the liver
D. Dehydration of bicarbonate ions in plasma
B
- A patient with decreased ventilation and increased pCO2 is likely experiencing:
A. Respiratory alkalosis
B. Respiratory acidosis
C. Metabolic alkalosis
D. Metabolic acidosis
B
Respiratory alkalosis clinical signs
a. Deep, rapid breathing
b. Tetany, progressing to convulsions
Clinical signs of Respiratory acidosis
a. Respiratory embarrassment
b. Depression of central nervous system (disorientation, coma)
metabolic acidosis clinical signs
a. Hyperpnea
b. Depression of central nervous system (disorientation, stupor, coma)
Clinical signs of metabolic alkalosis
a. Depressed breathing - slow and shallow
b. Tetany, progressing to convulsions
very helpful as an indicator of hemoconcentration
PCV / hemoglobin
a useful double check for hemoconcentration
serum or plasma protein
most often an indication of severe dehydration or shock
High BUN
Clinical signs of acid-base abnormality
abnormal respiration
Respiratory disorders can only be identified accurately by estimation of?
pCO2
Metabolic disorders are reflected in the plasma _______ concentration
bicarbonate
indicates the severity of the actual derangement in the body
blood pH
a laboratory test aimed to measure the metabolic factor bicarbonate
CO2 or Total CO2
Elevated potassium values are usually the result of severe ______ causing
intracellular K+ to more into the ECF
acidosis
Enumerate the 9 battery of tests necessary to answer the four important questions regarding fluid balance in a clinical patient
PCV, Total Protein, BUN, Na+, K+, Cl+, pH, pCO2, HCO3-
What are the 4 abbreviated battery of tests usually more practical?
Total Protein, Na+, K+, HCO3-
1 gram of sodium bicarbonate provides ________ of bicarbonate
12 mEq
1 gram of potassium chloride provides ______ of potassium
14 mEq
Solution given to patient with severe metabolic acidosis without low sodium value
Isotonic sodium bicarbonate or
isotonic sodium lactate
Correction of acidosis can be accomplished by the administration of very hypertonic solutions of ________ ?
sodium bicarbonate (5% NaHCO3 in saline)
Correction of acidosis can be accomplished by the administration of very hypertonic solutions of sodium bicarbonate (5% NaHCO3 in saline) in relatively
small quantities of?
2-3 L/500 kg
HCO3- deficit/L x _________ = mEq. needed
ECF (liters)
HCO3- deficit/L = ______ - Patient HCO3-
Normal HCO3-
_____ = Body weight (kg) x 0.3.
ECF
In treating severe hypokalemia, supplementation of lactated Ringer’s solution with _____ of potassium chloride (1-3 grams/L) may be useful.
10 to 50 mEq/L
average daily intake of _____ contains more potassium than 100 liters of lactated
Ringer’s solutions
hay
measurement of the acidity of the blood, reflecting the number of hydrogen ions
present
pH
reflects the amount of carbon dioxide gas dissolved in the blood
pCO2 (Partial Pressure of Carbon Dioxide)
primarily measures the effectiveness of the lungs in pulling oxygen into the blood
stream from the atmosphere
pO2
Elevated CO2 levels are seen in?
- Severe vomiting
- Use of mercurial diuretics
- COPD
- Aldosteronism
measures the percent of hemoglobin which is fully combined
with oxygen
Oxygen Saturation (SO2)
acidosis due to decrease of HCO3- by being used to buffer H+ that is being produced excessively
Titrational acidosis
acidosis due to HCO3- loss in the body such as extreme salivation or it is not being produced
secretory acidosis
hallmark of acidoses
hyperchloremia
this type of acidoses is due to excess of free H2O in the plasma that dilutes electrolytes proportionately
dilutional acidosis
When an animal has concurrent alkalosis, hypochloremia, and hypovolemia, and kidneys produce acidic urine
Paradoxical aciduria
