Why are my anion gap values out of normal range?

Hi doctor,

My three questions are related to laboratory investigations that I got done last month.

1) I would like to have a verification that I calculated this correctly.

Anion Gap (with K) = (Na + K) - (Cl + HCO3). When I do this using my laboratory investigation values, I get (138 + 3.7) - (102 + 19) = (141.7) - (121) = 20.7 Even when I use other types of calculations, such as leaving out potassium. I still get 17.

Of the slightly varied formulas I have found, the lowest result I come up with is 16.8; that one uses an albumin adjustment. But, I do not know if it is appropriate to do that, as I mentioned. I do not know why this is happening.

2) If my laboratory investigation values do show an out of normal range anion gap, then I would like to know why?

3) I would like to know what I should be doing about it.

Hi doctor,

Thank you so much for validating my concerns.

I am generally able to continue on even when I do not feel well, but this is different. I feel 'off' and unwell in a way that is different than any prior health issues. I am in a Ph.D. program, finishing up my dissertation, trying to manage the two classes I am teaching, and barely able to concentrate most of the time. I can force myself through maybe a quarter of the workload I used to do; my ability to concentrate and my stamina both feel impaired.

To answer some of your questions:

Blood Pressure/blood flow:

My blood pressure during my last doctor's visit just last week was 110/80 mm Hg. It is normally in that range. However, in the past two years, I have begun to see upward fluctuations to as high as 150/110 mm Hg. These swings upward are always temporary; wearing compression socks, rapidly drinking 24 oz of water, and shifting position will cause it to drop back to the normal range. It is 90% of the time: 110/80 mm Hg.

The nurse practitioner at my neurologist's office has prescribed Droxidopa for me around two years back in an attempt to address the orthostatic issues I had since my teen years. I stopped taking it in the middle of last year out of a concern that it might be the cause for those blood pressure spikes.

I had radio-frequency ablation of three uterine fibroids around four years back, following iron deficiency anemia due to heavy periods. The surgery was effective, and my menstrual cycle is more normal now. I did require two infusions of I.V iron five years back due to the heavy menstrual bleeding.

I have recently been diagnosed with chronic venous insufficiency; after a vascular ultrasound of the veins in my legs. I was told that they are all nearly twice larger than normal, eight to nine mm instead of four to five mm. I do not have any varicose veins, so this was a surprise to me, but my vascular doctor said that due to my Ehlers-Danlos syndrome and overly stretchy collagen, this was not unexpected. I also have a diagnosis of vascular thoracic outlet syndrome in my right arm. My vascular doctor ordered a chest CT that was performed last week; the results were normal.

My low mean platelet volume, from three months back and last month, was 6.7 and 6.9, respectively. I know there is research indicating that postural orthostatic tachycardia syndrome is associated with platelet storage pool deficiency, but I cannot see a specialist hematologist until three months from now, and I do not know if that would have anything to do with my high anion gap.

Ketoacidosis:

I am not on any medications to control blood sugar. My glucose has never been out of range, and all of my HBA1c tests have been within normal range. I have worried about the possibility of diabetes due to episodes of intense thirst, even waking up in the middle of the night thirsty. And the fact that most of what I drink seems to leave immediately as urine instead of helping me feel less dehydrated. But, the feeling of thirst is not constant, and none of my blood sugar evaluations have ever been out of normal limits.

I have attached both my last HBA1c test and my last urinalysis showing negative ketones.

I also, two months back, started testing my urine with test strips and recording the results on a phone app. That may sound odd, but I was so frustrated with being told that I was not drinking enough water that I decided to track the specific gravity of my urine just so someone would believe me about my fluid intake.

Alcohol Intake:

When I saw my third cardiologist more than a year back, I was told that my tachycardia was caused by me "dehydrating myself" and sent away with instructions to stop my four oz cup of coffee in the morning, cut all alcohol, and return in three months. I have followed the second instruction but have been given permission to keep the four oz of coffee in the morning by my dysautonomia specialist; I cannot handle the constipating side effects of oral iron without it. I do not think the two two oz cocktails I had per week were a problem, but I wanted to try just in case.

I had no alcoholic drinks in the last two months. I have had two drinks this month as part of my birthday dinner.

Salicylates, acetaminophen, Lorazepam:

No Lorazepam or other similar drugs I took. I do occasionally take Acetaminophen, but always well under the maximum daily dose.

I was on NSAID for eight years and have only stopped it as of four months now. When I saw that my ferritin level was again low, I stopped taking my daily NSAID out of concern that it might be causing a slow, unnoticed GI bleed. I do not have any gastric distress or black stools and have an appointment with a gastroenterologist this coming week to rule out this possibility.

I was on Gabapentin enacarbil for ten months last year as a treatment for my thoracic outlet syndrome pain. I had been having muscle spasms and neuropathic pain in my right arm for three and a half years, and it had not resolved with physical therapy. A facet injection of Lidocaine between T3/T4 and T4/T5, plus nine months of NSAID, finally resolved the nerve pain. I stopped the 300 mg/day NSAID once the pain resolved.

Toxic alcohols:

Definitely not.

As to the respiratory question, I often feel as if I am short of breath when my heart rate spikes. I have tried to deliberately breathe more slowly, but the sensation of not having enough oxygen in my brain does not change until I lie flat with my legs elevated. My gynecologist, after looking at my laboratory investigation values, said, "It is almost like you are hypovolemic," - but she said that is outside her scope of practice, and I should talk to a specialist. I do know that when I have the lowest ferritin levels, my tachycardia and breathlessness are much worse.

Question regarding my cardiologist's instructions to drink 100 oz of water per day:

Is that possibly contributing to the anion gap problem? I know that people with POTS have abnormal renin-aldosterone issues but have never been evaluated for this.

Before last year, I was at 80 oz/day based on the recommendations of the three cardiologists I have seen in the past six years (the last one did not do any testing and insisted that all of my tachycardia was due to my four oz of coffee and not drinking enough water).

I even started tracking my hydration with an application in order to provide a record. I am happy to share the data log with you if you would like it. Half of that 100 oz is water with over-the-counter electrolyte powders, as instructed by providers; all have different percentages of sodium, potassium, and magnesium. Nobody has given specific feedback on a brand or a ratio of ingredients, so I am left to do my best to choose. In addition, I add one teaspoon of salt to my food per day based on instructions from two of the cardiologists. I have seen for tachycardia and the dysautonomia specialist that I am seeing now.

The day I had undergone investigations, my carbon dioxide was 19. I drank 24 oz of water before getting out of bed, as instructed by my dysautonomia specialist, then drank two 12 oz containers of water on the drive over to my appointment (so 48 oz total of water before I had my investigation that day). I also use an application to track the specific gravity of my urine - twice daily - because I have been hearing "you are dehydrated, drink more water" and "you are dehydrated, add electrolytes "or "add salt" from specialists for *years* now and no amount of water or electrolytes that I consume seems to alter my tachycardia issues. The persistent tachycardia, fatigue so intense I have had to cancel two classes in the last month, and other symptoms are interfering with my ability to work. I share all of this to avoid the standard initial response I have repeatedly received, which is someone telling me I am probably dehydrated.