lethargic(and need ABG) or just tired???

MoLee228 · Mar 17, 2011

I usually have the luxury of having an arterial line so getting an ABG is simple. But for a patient without an A-line, getting an ABG is painful and invasive. I would want to be fairly certain the patient is having respiratory issues before I would order a STAT ABG. Lethargy alone would certainly not make me think ABG. Check the patient's blood sugar, maybe they are low. Check all their vitals: if their O2 saturation is lower than normal, their respiration rate is increased, and they report feeling short of breath, then I would say it's time for an ABG. If you are unsure, grab a seasoned nurse on your floor who you trust for a second opinion. If possible, get a NP/PA/MD in there to look at the patient. Cover your bases. It's better to be safe than sorry! I would feel better having an MD order an ABG than doing it myself on a patient who needs to be stuck for it. But then again, I have lots of residents available to me around the clock, so if it's hard for you to get a doc in there things are a little different.

Sorry for rambling a little. Good luck!

FlyingScot, RN · Mar 17, 2011

Agree with above. I've had more than one ABG...they hurt like he**!

An ABG is not a benign procedure. There can be serious complications. Lethargy without any signs of respiratory distress is not an indication for such a procedure. There are so many other things that could cause it.

pink816 · Mar 17, 2011

Thanks for the replies. I do realize that there are many causes thats why I often am wondering do I need to get one or not. In the unit I am in, we do sometimes have an a-line depending on the surgery type. We have physicians readily available, it is just a standard that we can get an ABG if needed, we can get one and write the order then notify the doctor.

I guess I am just asking because when I think "lethargic" I often think it means the pt isnt doing well, however the true definition is just lack of energy. I have had pts who lethargic is documented as their LOC yet they can carry on a complete conversation just when you're not in with them, they are asleep most of the time.

merlee · Mar 17, 2011

If the pulseOx is a bit low, and there is some lethargy, first have them do a pulmonary toilet - you know, some deep breaths, coughs, etc. Then retest the pulseOx. Much cheaper and less invasive than an ABG!!!

Isabelle49 · Mar 17, 2011

I would also check pulse ox, if patient sleeping, may be breathing very shallow and may need extra O2. Would also need more history.

p_hawk · Mar 17, 2011

I'd also factor in how arousable they are... like you described before, a patient that's just "lethargic" might sleep all the time, but wake up easily and respond appropriately to questions. Where as someone who's hypoxic or hypercapnic might not. Know what I mean?

pink816 · Mar 17, 2011

things i definately do before getting an ABG include blood sugar, check vitals and pulse ox (I'm in the unit so they are right there on the screen), listen to lungs, see if pt is SOB, etc.

Thanks for all your replies!

Like I said before I think sometimes when I hear "lethargic" I think the worst when its not always the case.

MunoRN, RN · Mar 17, 2011

CO2, not O2, is what you're looking for if you're concerned about the cause of lethargy related to opiate use. This is why end tidal CO2 (not O2 sat) is considered the gold standard for monitoring sedation in post-op patients on opiates. It's completely possible for the O2, both on a pulse ox and on ABG's, to be normal but CO2 levels to be elevated, particularly if you are supplying supplemental oxygen.

Without an art line, ABG's is painful and invasive, but venous CO2 levels are of some use. You can compare the patient's baseline venous CO2 levels with current, or supposedly arterial CO2 is approximately equal to venous CO2 x 0.83. Really, an end tidal CO2 monitor (similar to a pulse ox monitor) is the best option.

GreyGull · Mar 18, 2011

Hello,
I work in a post surgical unit and often my pts are medicated with Norco or morphine/fentanyl. I wonder how to tell sometimes if someone is just tired or if they are lethargic and needs an ABG. If someone is lethargic is it likely that the O2 sats are low (cause I know it isn't always the case correct)?

Check the patient first and apply the appropriate intervention. You have an SpO2, RR and breath sounds for assessment to initiate supportive treatment. You don't need an ABG for that. As others have mentioned there are other reasons for lethagy and once those are corrected, you may find there is no need to stick an artery.

Check airway. Occluded from sedation or lethagy?

Any response to any stimuli?

Check the medications. Could the patient be over medicated or just sensitive to the med? Some post op units now have ETCO2 monitors just as those doing moderate sedation.

Check the lung sounds. Aspiration or clear but depressed efforts?

Check BP. Too low?

Check temperature. Still cold?

Check glucose.

Any risk for emboli from medications being held for surgery?

However, the one thing that an ABG might show, other than what you should know about the respiratory system, is profound metabolic acidosis. Depending on the surgery done (ex. GI or kidney) and fluid status this would be a legit reason for an ABG which an ETCO2 monitor might not pick up.

The one thing that might help for these situations it to look over the protocols for a Rapid Response Team.

Southern Fried RN · Mar 18, 2011

CO2, not O2, is what you're looking for if you're concerned about the cause of lethargy related to opiate use. This is why end tidal CO2 (not O2 sat) is considered the gold standard for monitoring sedation in post-op patients on opiates. It's completely possible for the O2, both on a pulse ox and on ABG's, to be normal but CO2 levels to be elevated, particularly if you are supplying supplemental oxygen.
Without an art line, ABG's is painful and invasive, but venous CO2 levels are of some use. You can compare the patient's baseline venous CO2 levels with current, or supposedly arterial CO2 is approximately equal to venous CO2 x 0.83. Really, an end tidal CO2 monitor (similar to a pulse ox monitor) is the best option.

Agreed. I've seen patients with 100% o2 sat, RR 16, obtunded with a pH of 7.19 and pCO2 of 90.

Some patients may be undiagnosed OSA, then add general anesthesia and narcotics....you are definitely right to be concerned and not brush it off as just medication. I've heard two horror stories where a patient with undiagnosed OSA getting Dilaudid post-op only to be found dead (both at local hospitals).

FlyingScot, RN · Mar 18, 2011

An EtCO2 reading will be quicker, cheaper and far less painful. If the CO2 is elevated then you would have a reasonable rationale for an ABG. Plus are we talking about a lethargic patient or an obtunded patient? For me these are two entirely different assessments (although I am conceding that an obtunded patient was most likey lethargic prior to becoming well...obtunded).