Respiratory Alkalosis with Metabolic Acidosis? Anion Gap Question

October 19, 2024 9:51 PM

So for the past few years have had a consistent serum PH of 7.54. Have had a history of upper respiratory infection (bronchitis and pneumonia) but the alkalosis has been a presentation since a dx of primary hyperparathyroidism. The anion gap notes is 4.3. Consistently.

I've been waking from sleep with hyperventilation - would this cause for the ongoing respertaroy alkalosis? Due to the slight complexity of my situation, and ongoing health issues I've been left in the dark as to the origin of the alkalosis. Nephro, cardio, endo have been consulted and nephro looking at my numbers concluded this is respiratory alkalosis and not metabolic.

To note, also have periodic hypophosphatemia which I'm now supplementing phos for. But my question is - would an obstruction such as a tumor be the cause of hyperventilation? All imaging done - sestamibi, ultrasounds - could not find the tumor. Did endoscopy - clear. Could this be hypoxia based on THESE LAST LAB RESULTS indicate it? And if this is metabolic acidosis how would that be established as being the case? I was given no indication by any of the doctors the etiology of the RA, how to deal except that it somehow was tied in to the hyperparathyroidsim. Kidneys were cleared of being culprit, cardio cleared me for surgery (which is being held up due to semantics) and endo wasn't sure about anything. I do not know what to do now - who to consult. There is no coughing, sometimes I have dysphagia but it comes and goes - and endoscopy as said, was clear. ENT said it was clear. What am I missing in this dx, what should I be seeking out (aside from the surgery) in terms of dx and do I need supplemental oxygen based on those labs? Is this anion gap something to be concerned about? And if so, why are the doctors silent about it?

posted by watercarrier to Health & Fitness (2 answers total)

I'm sorry you're not getting the answers or reassurance you're looking for from your medical staff. Here's a little info on your questions:

Anion Gap is a calculated value based on the difference between total cations (sodium and potassium, positively charged ions) and total anions (chloride and bicarbonate, negatively charged ions). By itself it isn't going to point to any particular diagnosis, but might prompt more investigation into a potential cause. It sounds like much of this is ongoing.

Over time, if you have some other derangement of lab values, the gap will often change because other positive or negative ions are being produced by the body (lactic acid, ketones, foreign substance overdose, etc). We are always trying to reach homeostasis, so the body (often the kidneys) will shift those cations and anions around so that your pH remains as close to optimal for the body systems to function.

An obstruction in the lung might reduce available lung tissue, causing your body to respond by breathing more quickly, yes. This will often result in a respiratory alkalosis, as CO2 is exhaled at a greater rate.

Your lab values, assuming that is an arterial blood gas with standard reference ranges, show alkalosis, with slightly low CO2 and slightly elevated HCO3. Both of these values represent a mild alkalosis. Your PO2 seems quite low, which makes me wonder if this is a venous blood gas, not arterial. Arterial gases are taken with a radial artery stick - did you get a lab draw from your wrist?

What all of that means, I'm not sure, but hopefully that helps with the foundations of what you're looking at.
posted by Pantengliopoli at 10:38 AM on October 20

But my question is - would an obstruction such as a tumor be the cause of hyperventilation?

I mean, everyone's different, but my parathyroid tumor was a bit over 3 centimeters in diameter, which is on the large side so far as these things go, and my breathing was not obstructed. Oximeter was always 96 or above. My voice was a little growl-y and hoarse before the 'ectomy, though.
posted by mochapickle at 1:06 PM on October 20