Arterial Blood Gas - I Asked About It Finally

Because it's been mentioned several times since I've been here, I finally asked my doctor about doing an arterial blood gas and if there was any reason to (or not to) do one at this time. This was her answer to that question:

"The arterial blood gas can tell us 2 things, the ability to get oxygen in and also whether there is adequate ventilation to remove carbon dioxide, CO2. We get a pretty accurate idea of the oxygen level from the oxygen saturation.
People with neuromuscular disease can have a decrease in ventilation causing the CO2 to increase. This is usually seen only after the vital capacity gets to be about a third of normal expected level. I usually start to check blood gases this when the vital capacity gets to aroung 40% of predicted. You were well above that on your test last fall and we will recheck the vital capacity when you come to clinic next time."

Any comments?

Your doctor's reasoning sounds very sensible to me. I've had 3 ABGs and they've never been any more uncomfortable than a regular blood draw or IV set - BUT - MANY say that the ABG is very painful for them. There is a nerve or maybe more than one nerve close to the artery at the wrist where the ABG draw is done. Arteries are deeper than veins.

My last ABG was not any more uncomfortable than any other blood draw or ABG - UNTIL "after" the draw I offered to hold the gauze over the puncture whilst the RRT took care of the vial. Ha! I pressed too hard on the gauze and that nerve YELLED at me good!!! Of course, I immediately let up on the pressure and there was no more pain or even discomfort.

I sometimes think it is the power of suggestion. When I was sent for my first ABG I'd never heard of it before, all I knew was that it was some sort of blood draw. And it felt no different than a regular blood draw so I was relaxed about the next two and neither was any more uncomfortable than the first or other blood draws. I do know when I heard that ABGs were so painful I remember thinking, darn! I wish I remembered the name of the "tech" who did my first ABG!!!! I'd be sure to ask for her again. But the next two were done by different "techs" and were not uncomfortable either - except for my own blunder after the last one that I mentioned above.

I have COPD so I've often wondered WHY I haven't been ordered more ABGs. Your doctor's reason makes perfect sense to me and explains WHY I haven't had more.

Hi Slinky!

Thanks for this information. Being truthful, I kind of hope they decide NOT to do this because it already doesn't sound like a pleasant experience!! I HATE getting IV's and the like, so I'm guessing this would be a little stressful for me.

Thank you for sharing that it seems what my doctor is saying sounds correct. I DO trust her. The only reason I asked is that it's been brought up numerous times.

It seems that until my PFT's start showing increased problems, she's not going to worry about doing an ABG and based on your description and experience, I'm lucky!!

Madalot wrote:Hi Slinky!

Thanks for this information. Being truthful, I kind of hope they decide NOT to do this because it already doesn't sound like a pleasant experience!! I HATE getting IV's and the like, so I'm guessing this would be a little stressful for me.

Thank you for sharing that it seems what my doctor is saying sounds correct. I DO trust her. The only reason I asked is that it's been brought up numerous times.

It seems that until my PFT's start showing increased problems, she's not going to worry about doing an ABG and based on your description and experience, I'm lucky!!

I agree, Kathy, this sounds like good reasoning to me also. I have had this done once, several years ago, and I know I was nervous about it. I do not mind the usual blood test "stick" but I really hated that one, and I do mean HATED it. Maybe it was my nervousness, I dont know, but I am glad you don't need it right now and again, what your doctor said makes MUCH sense. Also, I am glad you got the question asked and answered, as I know you wanted to.

All the best as always,
Jeanette

Well, when and if the time comes you can ask if they can or will do that topical numbing bit that dentists use and some facilities use prior to an IV stick. My neighbor has a TERRIBLE pain tolerance level. She can't even tweeze a chin hair as it hurts too much. They always use that "number" on her before setting an IV.

Slinky wrote:Well, when and if the time comes you can ask if they can or will do that topical numbing bit that dentists use and some facilities use prior to an IV stick. My neighbor has a TERRIBLE pain tolerance level. She can't even tweeze a chin hair as it hurts too much. They always use that "number" on her before setting an IV.

Before we moved to the rural area we're living in now, we lived in a major Metropolitan area. I remember them using a numbing medication prior to inserting an IV. When I was having surgery down here, I asked about numbing it first and the nurse put me in my place very quickly -- "We don't even use numbing medications on BABY's, so no, we don't use it."

Perhaps when my doctor decides to do it, I can get it done at her facility where I'm more likely to get the numbing medication!! Let's hope!

I went digging through my records, because I seem to have ABGs done every year - and the only figure I can find for vital capacity is from 5 years ago when my capacity was 39% - so that makes sense according to what your doctor said.

I've never found them to be as bad as getting an IV placed, but they are definitely more stinging than regular blood draws and the discomfort does linger for a bit.

Slinky wrote:Well, when and if the time comes you can ask if they can or will do that topical numbing bit that dentists use and some facilities use prior to an IV stick. My neighbor has a TERRIBLE pain tolerance level. She can't even tweeze a chin hair as it hurts too much. They always use that "number" on her before setting an IV.

Oh Slinky, I wish I had thought of that during all of hubby's surgeries! He's the best patient in the world and never complains but if you ask him about his worst hospital experience he'll tell you it's the IV, he has tiny veins and he hates it! You'd think the nurses would know about it. Hopefully it won't be necessary again but thanks for the tip.

I've had ABG's twice, even tho I'm sure I didn't meet the stated criteria, but I'm sure every case and cause is different. Working is a hospital lab, I knew the horror stories, but mine turned out to be uncomfortable a bit, but overall uneventful, even tho they had to call a second person in to try the first time. The infamous nerve stayed out of the way I guess.

Thanks to everyone for their input. It's good to hear experiences from others. I guess when the time comes that my doctor feels she needs to do an ABG, I can trust that it's time for it and it will help her determine where my condition is at that point and the best way to continue treating it.

Madalot, I've also had an ABG done. It appears (from long experience) that my blood vessels roll around more than is normal. So, it's not unusual for nurses (and doctors) to need to "fish about" to find my veins and arteries. And yes, it was definitely uncomfortable. But it was not the worst pain I've ever had. In fact, since you deal with the constant torture of not breathing well, I think you will find it tolerable. As least when I compare it to the panic/fight/flight of awakening in the middle of a deep central apnea... It just was not that big a deal. And I do not think that I do all that well at tolerating pain.

I am again impressed with the reasoned approach of your doctor. She does not appear to use tests as "CYA", but as a true diagnostic tool. Much better approach for you. Glad you appear to have such a capable doctor on your side!

JohnBFisher wrote:Madalot, I've also had an ABG done. It appears (from long experience) that my blood vessels roll around more than is normal. So, it's not unusual for nurses (and doctors) to need to "fish about" to find my veins and arteries. And yes, it was definitely uncomfortable. But it was not the worst pain I've ever had. In fact, since you deal with the constant torture of not breathing well, I think you will find it tolerable. As least when I compare it to the panic/fight/flight of awakening in the middle of a deep central apnea... It just was not that big a deal. And I do not think that I do all that well at tolerating pain.

I am again impressed with the reasoned approach of your doctor. She does not appear to use tests as "CYA", but as a true diagnostic tool. Much better approach for you. Glad you appear to have such a capable doctor on your side!

Thanks John. When my doctor decides that I need to get an ABG, I'll survive it I'm sure. I won't enjoy it, but it's one of those things you just have to get through!

Thanks for expressing your feelings that my doctor is doing a good job. I was very impressed that she answered my question so thoroughly (rather than just saying that I didn't need the test). I am very glad that I didn't listen to my former RT and dump this doctor (my RT tried to convince me she wasn't very good). The more I work with my doctor, the more I realize she really is good -- she just doesn't say a whole lot unless you ask her specific questions!