ABG Interpretation...Not The Norm

[CodeBrownQueen, ASN, LPN]

Hi All,

Lowly student here with the results of an "expanded" ABG lab study and I have no clue what I am looking at beyond pH, PCO2, HCO3 and am hoping someone can clarify.

Specimen type: Arterial

pH: 7.41

pCO2: 36.8

pO2: 224.6 (High)

ABG HCO3: 22.7

ABG O2 Sat Cal/Meas: 99.5

ABG Base Excess: -1.5

ABG Hemoglobin: 12.2

ABG Oxyhemoglobin: 69.40 (Low)

ABG Carboyhemoglobin: 0.3

ABG Methemoglobin: 0.6

Allen Test: N/A

Sodium: 124.3 (Low)

Potassium: 4.3

Vent Mode: AC

Vent Rate: 14.00

FiO2: 100

Tidal Volume: 450

PEEP or CPAP: 10

Unless indicated labs are normal, the patient is on a TP vent. I am aware the last five items are related to the vent and vent settings, I included them for reference and a bit of background.

By all tense and purposes the ABGs are "normal". Patient may be hyperoxygenated based on the pO2? Not sure though and any insight would be appreciated.

Cheers.

[CodeBrownQueen, ASN, LPN]

I forgot to include: the sample is arterial.

[CodeBrownQueen, ASN, LPN]

:drowning:xx

[vanilla bean]

You are correct about the *blood gas* values (pH, PaCo2, PaO2, SaO2, HCO3, base excess) being normal other than the PaO2 showing hyperoxygenation. The other components are not part of a standard ABG but are either additional lab values or information entered to reflect the respiratory status of the patient.

Different facilities have different lab equipment at their disposal (either at the point of care or in the lab) that can allow them to run the same ABG and obtain additional lab values. One such device is the iSTAT; it allows bedside testing of ABGs and also provides values for other labs. Where I work, our iSTATs provide electrolyte and blood sugar results in addition to the ABG results. They can be configured differently to include other labs and there are more than likely other devices on the market that work similarly (I'm only familiar with the iSTAT).

[vanilla bean]

I forgot to include: the sample is arterial.

You didn't need to include that - that's what the "A" in ABG stands for (ARTERIAL blood gas). Results from a venous blood gas are VBGs.

[CodeBrownQueen, ASN, LPN]

Hi VB,

Forgive the severe truncation . Based on your knowledge, and the values presented, are you familiar with what the abnormalities indicate? Or is there some kind of standardized algorithm like the *blood gasses* (pH, PaCo2, HCO3) for determining the respiratory status?

[vanilla bean]

The high PaO2 is a direct result of the 100% O2 being delivered to the patient via the vent (the PEEP is also a *strong* factor in oxygenation; mode, rate, and tidal volume will also affect oxygenation). In terms of the oxyhemoglobin, I found a good article that you can take a look at here. The values of oxy/carboxy/met-hemoglobin are not normally included in standard blood gas studies. The low sodium is unrelated to the patient's respiratory status.

[Kuriin, BSN, RN]

Where I work, our iSTATs provide electrolyte and blood sugar results in addition to the ABG results.

I believe you mean VBG. You would not get an ABG from venous, nor will it be read in an iStat.

[BrendanO, MSN, RN]

I believe you mean VBG. You would not get an ABG from venous, nor will it be read in an iStat.

What? iStat cartridges work with venous or arterial blood for electrolytes, glucose, and BGs.

[Kuriin, BSN, RN]

Weird. We never did ABG with our iStats in the ED.

[AJJKRN]

Weird. We never did ABG with our iStats in the ED.

Pts in our ICUs usually have arterial lines in place to draw off of.

[Kuriin, BSN, RN]

I actually just remembered there is an option for Arterial and Venous before inserting the cartridge. My mistake!