need help with ABG intrepretation

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i'm having problem with interepretating my patient's abg result can someone help me with it?

1) normal ph, normal hco3, low co2 (30) --- is that respiratory alkalosis?

2) high ph (7.50), high co2 (50) high hco3 (30) --- is that metabolic alkalosis?

1) Need ALL the ABG numbers but it looks like fully compensated metabolic acidosis.

2) Need ALL the ABG numbers but it looks like a COPD pt.

Specializes in orthopaedics.

respiratory acidosis= decreased ph increased hco3 increased pco2

respiratory alkalosis= increased ph decreased hco3 deacreased pco2

metabolic acidosis= decreased ph decreased hco3 decreased pco2 =hyperventilation

metabolic alkalosis= increased ph increased hco3 increased pco2=hypoventilation

the bold indicates the primary abnormality.

1) normal ph, normal hco3, low co2 (30)

normal abg, acute hyperventilation

or

acute asthmatic getting ready to crash.

the p02 would indicate the difference.

with just these numbers the abg really isn't acidotic or alkalotic anything. the ph is normal, the pco2 is off but it's not trying to compensate for anything. if it was fully compensated the hc03 would be off too. it's just hyperventilation that hasn't affected the ph yet. or an asthmatic getting ready to fall on the floor. :uhoh21:

2) high ph (7.50), high co2 (50) high hco3 (30) --- is that metabolic alkalosis?

yes, metabolic alkalosis. whichever compensatory mechanism is the same as the ph... that's the acidotic/alkalotic choice.

ph : alk

pc02 : acid

hc03 : alk

just for information purposes, these are abgs for the 3 stages of an asthma attack:

  • phase 1 (mild): respiratory alkalosis: high ph, low pco2, normal or high po2
  • phase 2 (mod): normal ph, near normal pco2, decreased po2
  • phase 3 (severe): respiratory acidosis: low ph, high pco2, low po2 - prepare for intubation, especially if signs of decreased mental status
1) normal ph, normal hco3, low co2 (30)

normal abg, acute hyperventilation

or

acute asthmatic getting ready to crash.

the p02 would indicate the difference.

with just these numbers the abg really isn't acidotic or alkalotic anything. the ph is normal, the pco2 is off but it's not trying to compensate for anything. if it was fully compensated the hc03 would be off too. it's just hyperventilation that hasn't affected the ph yet. or an asthmatic getting ready to fall on the floor. :uhoh21:

2) high ph (7.50), high co2 (50) high hco3 (30) --- is that metabolic alkalosis?

yes, metabolic alkalosis. whichever compensatory mechanism is the same as the ph... that's the acidotic/alkalotic choice.

ph : alk

pc02 : acid

hc03 : alk

just for information purposes, these are abgs for the 3 stages of an asthma attack:

  • phase 1 (mild): respiratory alkalosis: high ph, low pco2, normal or high po2
  • phase 2 (mod): normal ph, near normal pco2, decreased po2
  • phase 3 (severe): respiratory acidosis: low ph, high pco2, low po2 - prepare for intubation, especially if signs of decreased mental status

i disagree with your 1st observastion. any asthmatic who can keep his co2 low at 30 is not crashing.

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