please help with these ABG's

[emmycRN]

82yo male on bipap FIO2 90% with diagnosis of pneumonia. o2 sats WNL.

ph 7.54

pco2 51

p02 64

hco3 43.6

BE 18.5

I am a relatively new ICU nurse and ABG's aren't my strong point. Charge RN and RT said ABG results were respiratory alkalosis due to anxiety and pt fighting bipap. If this is correct why is bicarb so elevated. What is your interpretation of these results?

[ghmccart]

ph 7.54 ALK

pco2 51 acid

p02 64 ok

hco3 43.6 alk (metabolic)

BE 18.5 ALK

This Pt could have a history of COPD, and could be retaining, though is alkalotic. maybe this pt has been throwing up. possible hyperventilating w/ PN.

[BBFRN, BSN, PhD]

How about giving this PT some Diamox to get rid of the base. Hopefully we can achieved the diuretic effect plus getting rid of excess base.

That's what I was thinking as well.

[ECMOismygame]

ph 7.54 ALK

pco2 51 acid

p02 64 ok

hco3 43.6 alk (metabolic)

BE 18.5 ALK

This Pt could have a history of COPD, and could be retaining, though is alkalotic. maybe this pt has been throwing up. possible hyperventilating w/ PN.

most likely.

we have been taught that as a general rule the body will NOT overcompensate. what i mean is this: RN draws an ABG showing: pH 7.2, CO2 60, bicarb 28. in 4 days ABG shows pH 7.52, CO2 58, bicarb 36. the body will compensate to bring that pH back up to normal, but it will not "OVER DO IT" and push it across the other side of 7.4, and vice versa. if it does happen something else is causing this, not the body overcompensating.

[lindapalooza]

It looks like he is hypoxic so why would you think his O2 is WNL? What were his resps like? It looks like he was metabolic alkalosis and respiratory acidosis (compensation) dt his pnuemonia. The lasix was to clear his lungs, doesnt sound like his kidneys were failing but could be dt to his hypoxia.

[RNnewgrad]

Look at the Nomogram for ABG's in the following text

http://umed.med.utah.edu/ms2/renal/Word%20files/i)%20Acid_Base%20Disorders.htm

Nomograms are absurdly simple to use and will give you a more accurate insight into what is happening than those silly up down arrows.

Use one for a while and it will not be too long before reading the gas will come more easily

Wow! Love this link! Thanks!

[ECMOismygame]

just remember these quick and easy to learn formulas....

these are what should be the maximal compensations...

the compensation from metabolic system for respiratory problems

an acute acidosis HCO3= [(PaCO2-40)/15)]+24 +-2

a chronic acidosis HCO3= [(PaCO2-40)/10)]4 +24 +-2

an acute alkalosis HCO3= 24 - [(40-PaCO2)/5)] +-2

a chronic alkalosis HCO3= 24 - [(40-PaCO2)/10)]5 +-2

the compensation from the respiratory system for metabolic problems

acidosis PaCO2 = 1.5HCO3+8 +-2

alkalosis PaCO2 = 0.7HCO3+20