[Exam 2] Chapter 13: Fluid and Electrolytes: Balance and Disturbances (Page 283-288) Flashcards
Acid-Base Disturbances: What is plasma pH?
An indicator of hydrogen ion (H+) concentration and measures the acidity of alkalinity of the blood
Acid-Base Disturbances: Normal plasma pH?
7.35 - 7.45
Acid-Base Disturbances: The greater the concentration of H+, the more…
acidic the solution and the lower the Ph.
Acid-Base Disturbances: The lower the H+ concentration, the more
alkaline the solution and the higher the pH.
Acid-Base Disturbances: The hydrogen ions are buffered by
both intracellular and extracellular buffers.
Acid-Base Disturbances: Major extracellular buffer system is , and is assessed when?
Bicarbonate-carbonic acid buffer system,
And assessed when arterial blood gasses are measures
Acid-Base Disturbances: Normally, what is the pare of bicarbonate to carbonic acid?
20 Pair to 1 Pair.
If altered, pH will change.
Acid-Base Disturbances: CO2 is a potential acid, when dissolved in water it becomes
carbonic acid.
Acid-Base Disturbances: When CO2 is increased, what also happens?
Carbonic acid content is also increased. and vice versa.
Acid-Base Disturbances: What happens if either bicarbonate or carbonic acid is increased or decreased?
20:1 ratio is no longer maintained , and acid-base imbalance results
Acid-Base Disturbances: Less important buffer systems in the ECF include
inorganic phosphates and plasma proteins
Acid-Base Disturbances: Intracellular buffers include
proteins, organic, and inorganic phosphates and in RBCs, hemoglobin
Acid-Base Disturbances: What do the kidneys regulate?
Bicarbonate level in the ECF. , and can regenerate bicarbonate ions as well as reabsorb them from the renal tubular cells
In respiratory acidosis, what do the kidneys do?
Kidneys excrete hydrogen ions and conserve bicarbonate ions to help restore balance.
Acid-Base Disturbances: What do the kidneys do in respiratory alkalosis?
Kidneys retain hydrogen ions and excrete bicarbonate ions to help restore balance.
Acid-Base Disturbances: What do the lungs do for disturbances?
Lungs, under the control of medulla, control the CO2 and this the carbonic acid content of the ECF.
Do so by adjusting ventilation in response to amount of CO2 in the blood
Acid-Base Disturbances: Rise in the partial pressure of CO2 in arterial blood is a powerful stimulant of
respiration.
Acid-Base Disturbances: What happens to the respiratory system in metabolic acidosis?
Respiratory rate increases, causing greater elimination of CO2
Acid-Base Disturbances: What happens to the respiratory system in metabolic alkalosis?
Respiratory rate decreases, causing CO2 to be retained (to increase acid load)
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Metabolic acidosis is a common clinical disturbance characterized by a low
pH (Increased H+ concentration) and low plasma bicarbonate concentration
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): This is produced by
a gain of hydrogen ions or a loss of bicarbonate
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Can be divided into what two forms?
High anion gap acidosis and normal anion gap acidosis
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Anion gap refers to
the difference between the sums of all measured positively charged electrolytes (cations) and the sum of all negatively charged electroytes (anions) in blood.
Because cations usually are more, there is usually a gap
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Anion gap equations
Anion Gap = Na + K - (Cl + HCO3)
or
Na - (Cl + HCO3)
Potassium often omitted, so 2nd equation is used more often than the first
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Normal value for anion group without Potassium is
8-12 mEq/L
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Anion gap range is potassium is included?
12-16 mEq/L
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): How much do the unmeasures anions in the serum account for?
16 mEq/L or less
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Person is diagnosed with metabolic acidosis is determined to have normal anion gap normal anion gap metabolic acidosis if the anion gap is in what range?
W/O Potassium, 8-12
W Potassium , 12-16
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): An anion gap greater than 16 meQ suggests
excessive accumulation of unmeasured anions and would indicate high anion gap metabolic acidosis as the type
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Why does an anion gap occur?
Because not all electrolytes are measured. More anions left unmeasured than cations
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Low or negative anion gap may be attributed to
hypoproteinemia
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Normal anion gap acidosis results from the direct loss of
bicarbonate, as in diarrhea, lower intestinal fistulas, ureterostomies, and use of diretics
REnal insufficiency
Excessive administration of chloride
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Normal anion gap acidosis is referred to as
hypercholermic acidosis
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): High anion gap acidosis results from
excessive accumulation of fixed acid
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): IF increased to 30 mEq or more, than high anion gap metabolic acidosis is preseent regardless of
values of pH and HCO3.
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): High anion gap occurs in
ketoacidosis, lactic acidosis, and late phase of salicylate positioning.
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): In high anion gap, the hydrogen is buffered by HCO3 causing
the bicarbonate concentration to fall.
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit): Metabolic acidosis is characterized by
a low pH and low plasma bicarbonate concentration
Reduced or Negative Anion Gap without potassium range?
<8
Reduced or negative anion gap with potassium?
> 12
Reduced or negaive anion gap clinical significance ?
Hypoproteinemia
Normal Anion Gap without Potassium range?
8-12
Normal Anion Gap with Potassium range?
12-16
Normal Anion Gap Clinical Significance
Normal anion gap metabolic acidosis
High Anion Gap Without Potassium?
> 12
High Anion Gap with Potassium?
> 16
High Anion Gap CLinical Significance?
High anion gap metabolic ACidosis
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit), Clinical Manifestations: Signs include
headache, confusion, drowsiness, increased respiratory rate and depth, N/V.
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit), Clinical Manifestations: When does peripheral vasodilation and decreased cardiac output occur?
When pH drops to less than 7
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit), Clinical Manifestations: Physical assessment findings include
decreased blood pressure, cold and clammy skin, dysrhythmias, and shock
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit), Clinical Manifestations: Chronic acidosis is usually seen in those with
kidney disease
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit), Assessment and Diagnostic Findings: What is valueable in diagnosing metabolic acidosis?
Arterial blood gas measurements
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit), Assessment and Diagnostic Findings: Expected blood gas changes?
Low Bicarb Level (<22 mEq)
Low pH (Less than 7.35)
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit), Assessment and Diagnostic Findings: Cardinal feature of metabolic acidosis is
decrease in serum bicarbonate level, with hyperkalemia potentially following as well due to potassium leaving the cells
Acute and Chronic Metabolic Acidosis (Base Bicarbonate Deficit), Assessment and Diagnostic Findings: Why are low seurm calcium levels treated before chronic metabolic acidosis?
Treated to avoid tetany resulting from an increase in pH and decrease in ionized calcium
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess): What is this?
Clinical disturbance characterized by a high pH (decreased h+ concentration adna high plasma bicarbonate concentration
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Patho: A common cause is
vomiting or gastric suction with loss of hydrogen and chloride ions The gastric fluid loss would increase the alkalinity of body fluids
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Patho: Hypokalemia produces alkalosis in what two ways?
Kidneys conserve potassium, and therefore H+ excretion increases
- CEllular potassium moves out of the cell into the ECFin attempt to maintain near normal serum levels
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Patho: Chronic metabolic alkalosis can occur with
long-term diuretic therapy, villous adenoma, external drainage of gastric fluids, or significant potassium depletion
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Clinical: Primarily manifested by symptoms related to decreased calcium ionization, such as
tingling of the fingers and toes, dizzinenss, and hypertonic muscles.
Calcium decreased because it combines with serum proteins
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Clinical: Predominant symptom of alkalosis?
Signs and symptoms of hypocalcemia. This includes decreased respiration and atrial tachycardia.
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Clinical: Signs of chornic metabolic alkalosis include
Same as acute mtabolic alkalosis, potassium decreases, and U waves being seen
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Assessment and Diagnostic Findings: Arterial blood gasses reveal what?
pH greater than 7. 45 and a serum bicarbonate concentration greater than 26 mEq.
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Assessment and Diagnostic Findings: PaCO2 increases as the lungs attempt to compensate for
the excess bicarbonate by retaining CO2. This results in hypoventilation which may lead to hypoxemia.
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Assessment and Diagnostic Findings: Urine Chloride Levels are useful why?
MAy be more accurate estimate of fluid volume than urine sodium concentration.
Help to differentiate between vomiting, diuretic therapy, and excessive adrenocorticosteroiod secretions
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Assessment and Diagnostic Findings: Those with vomiting or cystic fibrosis, nutritional replacement, or those recieving diuretic therapy shw a urine chloride of what
Lower than 25 mEq
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Assessment and Diagnostic Findings: Urine Chloride values when patient as mineralcorticoid excess or alkali loading?
Hypovolemia not present, and concentration for Urine Chloride greater than 40.
Normal value should be less than 15
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Medical Management: Why must I/O be monitored?
Because of volume depletion from GI loss,
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Medical Management: Sufficient chloride must be available for the kidney why?
To absorb sodium with chlorice (allowing excretion of excess bicarbonate)
Acute and Chronic Metabolic Alkalosis (Base Bicarbonate Excess), Medical Management: Treatment includes
restoring normal fluid volume by administering sodium chloride fluids
Normal pH range?
7.35 - (7.4) - 7.45
Normal PaCO2 range?
35 - (40) - 45 mm Hg
Normal HCO3 range?
22 - (24) - 26 mEq/L
Normal PaO2 range?
80 - 100 mm Hg
Normal Oxygen Saturation level?
> 94%
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) : What is this?
Clinical disorder when pH is less than 7.35 and PaCO2 is greater than 42 mm Hg and a compensatory increase in the plasma HCO3 occurs. Either acute or chronic
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Patho: What is this always due to?
Inadequate excretion of CO2, with inadequate ventilation resulting in elevated plasma CO2 concentrations and increased levels of carbonic acid
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Patho: This occurs in emergency situations, such as
acute pulmonary edema, aspiration, pneumothorax, and overdose of sedatives
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Clinical Manifestations: Sudden increases in PaCO2 can cause
increased pulse and RR, increased BP, mental cloudiness, or confusion, and a feeling of fullness in the head.
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Clinical Manifestations: First sign in anesthetized patients?
Ventricular fibrillation
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Clinical Manifestations: Signs of this is severe?
Intracranial pressure may increase, resulting in papilledema, dilated conjunctival blood vessels.
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Clinical Manifestations: Chronic occurs in what diseases?
Pulmonary diseases such as chronic emphysema and chronchitis . sleep apnea, and obesity
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Clinical Manifestations: If PaCO2 increases rapidly, what happens??
Cerebral vasodilation will increase the intracranial pressure and cyanosis and tachypnea will develop
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Assessment and Diagnostic Findings: Arteriral blood gas analysis reveals pH and PaCO2 to be?
7.35 and PaCO2 greater than 42 mmHg
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Assessment and Diagnostic Findings: OTher diagnostic measures include
monitoring of serum electrolyte levels, chest x-ray for deterining respiratory disease, adn screening to see if overdose suspected
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Treatment: Treatment directed at and may include
Improving ventilation, and pharmacologic agents are used as indicated such as bronchodilators
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Treatment: Whys is 2/3 L of water recommended?
To keep the mucous membranes moist and thereby facilitate the removal of secretions
Acute and Chronic Respiratory Acidosis (Carbonic Acid Excess) , Treatment: Inapprorpaite mechanical ventilation is a problem because
it may cause rapid excretion of CO2 and that the kidneys are unable to eliminate excess bicarbonate quickly enough to prevent alkalosis and seizures
Acute and Chronic Respiratory Alkalosis (Carbonic Acid Deficit):What is this?
pH is greater than 7.45 and PaCO2 is less than 38 mmHg
Acute and Chronic Respiratory Alkalosis (Carbonic Acid Deficit), Patho: Always caused by
hyperventilation, which causes excessive “blowing off” of CO2 and hence a decrease in the plasma carbonic acid concentration
Acute and Chronic Respiratory Alkalosis (Carbonic Acid Deficit), Patho: Causes include
extreme anxiety, hypoxemia, early phase of salicylate intoxication, and gram negativef bacteremia.
Acute and Chronic Respiratory Alkalosis (Carbonic Acid Deficit), Patho: Chronic respiratory alkalosis results form
chronic hypocapnia, and decreased serum bicarbonate levels are teh consequence
Acute and Chronic Respiratory Alkalosis (Carbonic Acid Deficit), Clinical Manifesatations: Signs consist of
lightheadedness due to vasoconstriction and decresed cerebral blood flow, inability to concentrate, numbness and tingless from decreased calcium, tinnitus, and someitmes loss of consciousness.
Acute and Chronic Respiratory Alkalosis (Carbonic Acid Deficit), Assessment and Diagnostic Findings: How is this diagnosed?
Analysis of arterial blood gases.
Acute and Chronic Respiratory Alkalosis (Carbonic Acid Deficit), Assessment and Diagnostic Findings: In the acute state, the pH is elevated above normal because of
low PaCO2 and a normal bicarbonate level.
Acute and Chronic Respiratory Alkalosis (Carbonic Acid Deficit), Assessment and Diagnostic Findings: In the compensated state, kidneys had sufficient time to lower
bicarbonate level to a near-normal level
Acute and Chronic Respiratory Alkalosis (Carbonic Acid Deficit), Medical Managemen: If cause is due to anxiety, what must be done?
Patient is instructed to breathe more slowly to allow CO2 to accumulate or to breathe into a closed system. Antianxiety agent may be required to relieve hyperventilation
Mixed Acid-base Disorders: Example of a mixed disorder is
the simultaneous occurence of metabolic acidosis and respiratory acidosis durign respiratory and cardiac arrest
Mixed Acid-base Disorders: What mixed disorder cannot occur?
Mixed respiratory acidosis and alkalosis, because you cannot have hypoventilation and hyperventilation at the same time
Mixed Acid-base Disorders, Compensation: What compensates for each other to return pH to normal ?
Pulmonary and Renal Systems
Mixed Acid-base Disorders, Compensation: What does the body do in a single base disorder to compensate?
Tries to compensate by returning the ratio of bicarbonate to carbonic acid to the normal 20:1
Mixed Acid-base Disorders, Compensation: How do lungs compensate for metabolic disturbances?
Changing CO2 excretion
Mixed Acid-base Disorders, Compensation: How do the kidneys compensate for dysfunctions?
by altering bicarbonate retention and H+ secretions
Mixed Acid-base Disorders, Compensation: How to compensate in respiratory acidosis?
Excess hydrogen is excreted in exchange for bicarbonte ions
Mixed Acid-base Disorders, Compensation: How does the body compensate for respiratory alkalosis?
The renal excretion of bicarbonate increases and hydrogen ions retained
Mixed Acid-base Disorders, Compensation: How does the body compensate for metabolic acidosis?
Compensatory mechanisms increase the ventilation rate and the renal retention of bicarbonate.
Mixed Acid-base Disorders, Compensation: How does the body compensate for metabolic alkalosis?
Respiratory systme compensates by decreasing ventilation to conserve CO2 and increase the PaCO2
Mixed Acid-base Disorders, Compensation: Does compensation for metabolic imbalances or respiratory imablances work faster?
Metabolic imbalances
Blood Gas Analysis: Why is this used?
Often used to identify the specific-acid base disturabance and the degree of compensation that has occured
Blood Gas Analysis: BLood sample usually based on
an arterial blood sample
Blood Gas Analysis: Results of arterial blood gas analysis provide information about
alveolar ventilation, oxygenation, and acid-base balance
Blood Gas Analysis: What must you evaluate in the sample?
Electrolytes (Na, K, Cl) and CO2
Metabolic Acidosis, Primary Disturbance
Decrease in pH
HCO3 < 22 mEq.
Metabolic Acidosis, Respiratory Compensation and Predicted Response
Increase Ventilation anddecrease of PCO2
Metabolic Alkalosis, Primary Disturbances
Increase pH and HCO3 > 26 mEq
Metabolic Alkalosis, Respiratory Compensation and Predicted Response
Decrease ventilation and increased PCO2
Metabolic Alkalosis, Renal Compensation and Predicted Response
Decreased H+ excretion and Decreased HCO3 reabsorption if no renal disease
Respiratory Acidosis, Primary Disturbance
DEcrease pH and Increased PCO2 > 45 mmHg
Respiratory Acidosis, Respiratory Compensation and Predicated Response
None
Respiratory Acidosis, Renal Compensation and Predicted Response
Increased H+ excretion and Increased HCO3 reabsorption
Respiratory Alkalosis, Primary Disturbance
Increased pH and decreased PCO2 < 35 mm Hg
Respiratory Alkalosis, Respiratory Compensation and Predicted Response
None
Respiratory Alkalosis, Renal Compensation and PRedicted REsponse
DEcreased H+ excretion and Decreased HCO3 reabsorption
Normal Value of Arterial Blood, pH
7.35 - 7.45
Normal Value of Arterial Blood, PCO2
35-45 mmHg
Normal Value of Arterial Blood, PO2
> 80 mmHg
Normal Value of Arterial Blood, HCO3
22-26
Normal Value of Arterial Blood, Base Excess/Deficit
+2 mEq
Normal Value of Mixed Venous BLood, pH
7.32-7.42
Normal Value of Mixed Venous BLood, PCO2
38-52
Normal Value of Mixed Venous BLood, PO2
24-48
Normal Value of Mixed Venous BLood, HCO3
19-25
Normal Value of Mixed Venous BLood, Base Excess/Deficit
+5 mEq
Normal Value of Mixed Venous BLood, Oxygen Saturation
65-75 %