(2) Electrolytes, Minerals, & Gasses Flashcards
Metabolically produced acids include…
CO2
Examples of nonvolatile acids include…
Uric acid, phosphoric acid, and sulfuric acid.
Metabolically produced acids cannot be removed via the lungs, so they but be excreted through…
The kidney.
Why do blood and tissues contain buffer systems?
To minimize changes in hydrogen concentration.
With excess acid, H combines with what to form H2CO3?
Bicarbonate (HCO3).
When base is added to carbonic acid, it will combine with OH to form what?
Water and bicarbonate.
Reference range of pH.
7.35 to 7.45
Carbonic acid isn’t able to be quantified directly, so we measure…
PCO2; includes dissolved CO2.
Normal Plasma PCO2.
~40 mmHg
Normal bicarbonate concentration.
~24 mmol/L
The laboratory can assess acid-base status of a patient by measuring…
Blood pH, PCO2, and/or [HCO3].
The laboratory can measure 2 of 3 of pH, PCO2, or HCO3, and use what equation to measure the third?
Henderson-Hasselbalch Equation
How is pH and [HCO3] effected by acidosis?
Decreased.
How is pH and [HCO3] effected by acidosis?
Decreased.
Metabolic acidosis are categorized by the presence or absence of…
Anion gap and osmolal gap.
What equation is used to calculate the anion gap?
Anion gap=[Na] - [Cl] - [HCO3]
What equation is used to calculate the osmolal gap?
Osmolal gap = osm(measured) - (2[Na] + [glucose]/18 + [BUN]/2.8)
Normal anion gap.
<12
Normal osmolal gap.
<10
Metabolic alkalosis are disorders characterized by…
Chloride responsiveness or resistance.
Respiratory acidosis results from any impairment to…
Ventilation.
Respiratory acidosis causes include those directly affecting the lungs, these conditions include…
Airway obstruction, alveolar infiltrates, perfusion defects.
Respiratory alkalosis most often results from what condition?
Hypoxia (low blood oxygen levels).
Compensatory hyperventilation leads to…
Hypocapnea (low blood CO2 levels).
Reference range for pCO2.
35 - 45 mmHg
Reference range pO2.
80 - 100 mmHg
Reference range of HCO3.
22 - 26 mmol/L.
Reference range for TCO2 (Total CO2).
23 - 27 mmol/L.
Reference range of O2 saturation.
94% - 100%
Reference range of base excess.
-2 to +2.
The difference in CO2 concentration between cytoplasm and plasma results in diffusion from tissues into cells and the formation of…
Carbonic Acid.
Dissociation in plasma is very slow but is much faster in cells due to which enzyme?
Carbonic Anhydrase.
Which cells have the highest concentrations of carbonic anhydrase?
RBCs and renal cells.
Within the lungs, oxygen diffuses from the lungs to the blood forming…
Oxyhemoglobin
Describe the isohydric shift.
CO2 is exhaled and Hydrogen is buffered resulting in minimum change in pH.
The affinity of hemoglobin for oxygen depends on…
Temperature, pH, pCO2, and [2,3-DPG].
The kidneys reabsorb bicarbonate in the…
Proximal convoluted tubules.
What causes sodium reabsorption and exchanges it with either potassium or hydrogen ions?
Aldosterone.
Renal cells are rich in ___ which removes amino group from glutamic acid and converts it into ammonia.
Glutamate dehydrogenase.
Arterial blood pH reference range.
7.35 - 7.45.
Venous blood pH reference range.
7.32 - 7.42.
Chloride shifting occurs when the concentration of ___ in RBCs is greater than in plasma during the buffering process, ___diffuses out.
Bicarbonate.
Why does the chloride shift occur?
To maintain electrical neutrality.
When is chloride able to diffuse back into RBCs following a chloride shift?
When excess CO2 is expelled from the lungs.
Define acidemia.
Arterial pH <7.35.
Define alkalemia.
Arterial pH >7.45.
Define respiratory acidosis.
Insufficient elimination of CO2 by the lungs (hypoventilation). Compensation involves altered renal handline of bicarbonate.
Define respiratory alkalosis.
Excessive elimination of CO2 by the lungs (hyperventilation). Compensation involves altered renal handling of bicarbonate.
Define Metabolic acidosis/alkalosis.
Excessive intake of, excessive production of, or too little renal elimination of an acid or a base. The primary change is in bicarbonate. Compensation involves alterations in pulmonary handling of CO2.
Define simple acid/base disorder.
A primary acid-base disturbance and associated compensation.
Define a complex acid/base disorder.
There is more than 1 primary acid-base disturbance.
Normal rate of base to acid.
~20:1.
Base excess is a calculated parameter which describes…
Excess or deficit of base or bicarbonate.
Decreased base excess is an indicator of…
Metabolic acidosis.
Increased base excess is an indicator of…
Metabolic Alkalosis.
What type of puncture is required for PO2 measurement?
Arterial.
When collecting a blood gas sample, the phlebotomist must not place a…
Tourniquet.
What is the only anticoagulant that must be used for blood gases?
Heparin.
What does freezing the sample after collection do?
Impedes WBC metabolism.