Exam 1
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What type of specimen is used Gas analysis?
-Whole blood (Unclouded, unseparated)  -arterial most common -Venous is fine for acid-base
”capillary” can be considered as “arterialized”  if limb is warmed to _____ Degrees Celsius (Increases blood flow) prior to collection
45
What are four pre-analytical considerations for blood gas analysis?
-specimen container -Anticoagulants -Technique of collection -Storage and transport
What specimen containers can be used?
-glass (best for pO2), Well Stoppared-gas tight for 2 hours -plastic syringes (Permeable to gas) -Capillary tubes*
If plastic container is used for pO2, The sample must be analyzed within ____ Minutes of being drawn
15*
 Plastic is permeable to gas (ok for pH, pCO2, HCO3-, ___________ and ___________). 
Base excess, electrolytes
What anticoagulant is used for blood gas analysis?
Heparin
 do you want to use the minimum amount of anticoagulant necessary. Otherwise how would the results be altered?
Decreased pH, [HCO3-], base excess, Ca2+
What are the two forms of heparin?
-dry -Solution
Form of heparin that has the advantage of little dilution of specimen, disadvantage- takes time for heparin to dissolve and mix
Dry heparin
Form of heparin that is fast mixing but requires dilution of sample
Solution heparin
Form of heparin that… -decreased electrolytes, HCO3-, Hb -Increased pO2, Because 02 in heparin solution is equalliberated with atmospheric air
Solution heparin
Venous occlusion by tourniquet should be less than _____ Minutes
2
Where are the important factors for Specimen collection?
-patient should have calm, steady ventilation for 15 minutes, 30 minutes for patients receiving artificial air or CO2 -Pain and anxiety should be minimized -Sample should be drawn anaerobically in presence of anticoagulants -Samples with air bubble should be discarded -Keep Hemolysis to a minimum
How should glass specimens be stored? 
-Should be placed on ice/water slurry immediately (Slow down enzymatic activity)  -stable for about two hours
How should a plastic specimen be stored?
-should be analyzed immediately -Stable for 15 minutes 
Prolonged storage of specimen may decrease _____ and increase ______ (Recommended that samples be analyzed within one hour) 
Ca2+, K+
What are the analytical methods for determining acid base balances and blood gas analysis?
• pH electrode • pCO2 electrode • pO2 electrode
Calibrators, buffers and electrodes must be at the same ________. 
Temperature
How is pH electrode calibrated?
Calibrated with buffer solutions that bracket pH of sample (Normal 7.35-7.45) 
pCO2 electrode is a __________ pH Electrode.
Modified
How does pCO2 electrode determine pH?
Takes a vantage that pH has a linear relationship to log pCO2 Over the range of 10-90 mmHg (normal pCO2 is about 35 to 45 mmHg)
What is normal pCO2 range?
35-45 mmHg
 what are the two types of pCO2 electrode? 
-invasive: Requires blood to be drawn -Noninvasive: Transcutaneous pCO2 (tcpCO2)