ABGs

[twinkly29]

Hi everyone,

Does anyone else find that the ABG is often normal? I used to get a lot of hyperventilation results but now it's usually just within normal range with co2 at the low end of normal. I rarely wheeze, but have very tight chest, incessant coughing and fast breathing rate. Chest is often very quiet. SATs usually fine.

Thanks for any experiences.

[EmmaF91 Community Ambassador]

Hi

Yes I usually get normal ABGs. It is a good thing as it means you’re getting the right amounts of o2 in and co2 out!

I’ve only had it change once and that was the time I almost got intubated and put in ITU (luckily I picked up minutes before the decision was made!). That’s the reason why they do it as it can indicate the severity of the issue - at the time I had a silent chest so no wheeze either 😅 (wheeze is my last to come, first to go symptom!)

Hyperventilation ‘results’ can be seen as normal too as with asthma attacks most people panic and breathe faster, but once you’re treated everything calms and you’re back to normal (hence why asthma can ‘look’ like a panic attack if you don’t look at everything else - peak flow etc)

Hope that helps x

[Lysistrata Administrator Community Ambassador]

Yes I can have normal ABGs too. You sound similar to me in attacks with the no wheeze but quiet chest etc!

There are stages to.ABGs and one is where you are breathing fast to compensate for your narrowed airways - a resp rate over a certain level is used to assess the severity of the attack. This isn't just panic or emotional response (I am.pretty laid back in attacks) but a physiological response, as is increased heart rate - my HR goes up a lot too, does yours?

You do find some drs who do not know how to interpret asthmatic ABGs properly and will assume that lower CO2 means it is 'just hyperventilation or panic' which is not true. Normal to high CO2 with dropping oxygen is not a good sign, the lower CO2 part is an earlier and preferred stage!

I have had a sharp dr pick up on the fact that my ABG was taken while I was on O2-driven nebs and so the oxygen might be a little higher- he said it was perfect but was I on oxygen because he didn't think it quite reflected how I was! Other drs.have not accounted for that and I was thrown out of A and E once because they based it all on that (unusual as most do look at other things - this consultant was really horrible and wrote that I was anxious and making myself worse when drs saw me).

I have also had ABGs that showed something going on where the pulse oximeter didn't eg oxygen pressure and % not so good on ABG, and a not so good attack (thankfully not like Emma's!) where they did several ugh to see if it was improving. My current hospital is less keen on doing them it seems which is good for my wrist lol and go on other things, though this can be less good if they are too fixated on pulse ox and peak flow/wheeze (my peak flow doesn't necessarily drop as much as you'd expect).

Hope this helps - the joys of being a weird asthmatic!

[twinkly29]

Thanks for your replies!

Glad I'm not the only weird asthmatic! I like that phrase though.

Yes my heart rate is always high, sats good, no wheeze.

My new consultant (new area so new hospital) and his team seem really on the ball which is great but it's still hard being different to the norm!

[Melanie1989]

You could be describing me! I have the exact same. My last abg showed hyperventilation, no wheeze, sats normal and high hr. My bloods always show high lactate though which is weird! Ive had various experiences with A n e last one was awful! It is reassuring to see other asthmatics like me. I do feel for you though as i have often wished to be a 'normal' asthmatic.

[Js706 in reply to Melanie1989]

I think increased lactate is a possible side effect of salbutamol - at least, that's what I've been taught on placement! But there are loads of causes for it that could also be the culprit in asthma, like infection.

[Melanie1989 in reply to Js706]

Ah thankyou, that makes sense!

[Lysistrata Administrator Community Ambassador in reply to Melanie1989]

I also get increased lactate a lot and like Js706 says have read that it can be due to salb but also asthma. Not necessarily sure when it's one or the other - I think an especially high lactate is considered a bad sign in asthma.

[Js706 in reply to Lysistrata]

It’s one of those that is important to interpret in terms of the situation. Like if you’ve come in with a fever it’s probably being raised by an infection regardless of any salbutamol use!

I think it can be bad because it can increase if your oxygen is low (if I remember all my physiology you go into anaerobic respiration if you haven’t got enough oxygen and so make more lactate) but I suppose the low oxygen would also show up on the ABG.

If only all these tests were simple!