need help with ABG case study....

[timls3674]

the case study is ...

51 y/o male post orthpedic surgery for a ORIF for bilateral wrist fractures and L tib fib fracture, when you as the nurse enter his room you find him to be agitated and dsypneic and he says " my chest hurts real bad and i cant breathe"

The Doctor orders a ABG and the result of the ABG is:

pH 7.47, Paco2 33.6mm Hg, Pa02 52mm Hg, HC03 24.2 , and BE -3, Sa02 83%

first i have determined his ph is alkolotic, his Paco2 is alkolotic also, his HCO3 is within the normal range, and his BE of -3 is throwing me off

I have tried to use the ROME to figure it out but i am stuck on this part,

when i look at it i have determined that his Ph being high and his Pca02 being down it is respiratory alkolosis and looked at his HCO3 to be within normal limits so it isnt metabolic, however the BE is throwing me off being -3

is this correct ? respiratory alkolosis

when using the ROME method and if the HCO3 is within the normal ranges can you rule out metabolic problem?

for this case study the HCO3 was within the normals so did i follow the method for using ROME correctly to determine it wasnt a metabolic problem ?

Timls3674

[ghillbert, MSN, NP]

Resp Opposite: High pH, low CO2.

It's an uncompensated (because pH is not normal and HCO3 is normal) resp alkalosis.

You do not need to account for BE because -3 is normal.

[Daytonite, BSN, RN]

when assessing abgs you look at the ph first to determine acidity or alkalinity. this patient's ph is 7.47. he is in alkalosis. now you look at the respiratory component. that is the co2. it is 33.6. normal is 35 to 45, so this reading is low--below normal. next look at the metabolic component. that is the hco3. it is 24.2. normal is 21-28, so it is within normal parameters. since the only component that is abnormal is the co2 and it is a respiratory component there is nothing more to consider. this is respiratory alkalosis. the be and o2 are not important in basic abg analysis. there are only 3 components that are considered when analyzing abgs: the ph, the co2 and the hco3. the rome mnemonic is used when the ph is abnormal. in this case:

respiratory opposite

• ph elevated pco2 diminished = respiratory alkalosis
  
  
• ph diminished pco2 elevated = respiratory acidosis
  
  

metabolic equal

• ph elevated hco3 elevated = metabolic alkalosis
  
  
• ph diminished hco3 diminished = metabolic acidosis
  
  

when the ph is normal, but the co2 and/or the hco3 are abnormal you have compensation going on. then, you assess when the numbers are going this way:

compensated respiratory acidosis

• ph 7.35-7.40 / co2 >45 / hco3 >28
  
  

compensated respiratory alkalosis

• ph 7.41-7.45 / co2

compensated metabolic acidosis

• ph 7.35-7.40 / co2

compensated metabolic alkalosis

• ph 7.41-7.45 / co2 >45 / hco3 >28
  
  

please understand that all the above apply to abg results from a person's arterial blood sample. actual physical exam assessments of a patient's respiratory status must also be correlated with the abg results in the clinical area.

there are weblinks to tutorials and practice problems in abg analysis on post #45 of this sticky thread: https://allnurses.com/nursing-student-assistance/pathophysiology-p-microbiology-145201.html - pathophysiology/ a & p/ microbiology/ fluid & electrolyte resources

[Bortaz, MSN, RN]

Daytonite,

If I haven't told you this week how awesome you are, consider this my telling you.