Monday, November 14, 2011

Ketoacodis - Some Strange Cases

If you have type 1 diabetes, you have probably been warned about diabetic ketoacidosis- and if you haven't been, I'm warning you now.

Diabetic ketoacidosis is an acute complication of lack of insulin, relative or absolute, usually from type 1 diabetes. Here's what the term refers to:

Acidosis: arterial blood has a pH level that it likes- the normal range is 7.35 to 7.45 (slightly basic) Generally speaking, the diagnostic criteria for acidosis requires pH level to be equal to or less than 7.30, although sometimes acidosis is diagnosed or treated between 7.30 and 7.34

Keto: related to ketones. Ketoacidosis is acidosis caused by the presence of ketones, which for diagnostic purposes may be found in the blood or urine; in ketoacidosis there are usually ketones in both the urine and blood

Diabetic: having to do with diabetes. A person may be diagnosed with diabetic ketoacidosis by ADA standards if blood sugar on admission is over 200. Some places use a blood sugar cut-off of 250 or 300, and some places will diagnose "diabetic" ketoacidosis with blood sugars below 200 if the patient is known to have diabetes.

Diabetic ketoacidosis can develop in hours or it can take some time (maybe a month). It is a medical emergency and you can depend on being hospitalized if you are diagnosed with it. Severity ratings for ketoacidosis depend on pH levels (7.25-7.3 is mild, 7.00 to 7.25 is moderate, below 7 is severe) and/or symptoms. Death from ketoacidosis that is treated occurs at very different rates at different hospitals, but depends a lot on the severity of the ketoacidosis when treatment starts. Death rates for mild ketoacidosis may be below 1 in 200; death rates for severe ketoacidosis are as high as 1 in 5 when treated (untreated, all cases of severe ketoacidosis would likely lead to death).

Diabetic ketoacidosis risk factors include: being sick, especially when throwing up, pregnancy, not taking insulin, severe insulin resistance, insulin pump failure, eating disorders, being undiagnosed.

Now for some things you didn't know:

1. Diabetics go into ketoacidosis without high blood sugar more commonly than non-diabetics.

This article describes cases "euglycemic diabetic ketoacidosis". It is one of the first articles to describe the idea; a lot of diabetics with ketoacidosis who did not have very high blood sugars. The author suggests a blood sugar of below 300 as euglycemic, which has some obvious flaws (299 is a high blood sugar) but to be fair, he has 16 cases with blood sugars below 200, and 7 are below 100 (lowest blood sugar with a DKA diagnosis? 36!) All but one patient was already diagnosed with type 1 diabetes, hence the "diabetic" label. On what grounds ketoacidosis was diagnosed, I am not certain, given that he doesn't seem to have measured blood pH levels at all. Patients were symptomatic of ketoacidosis and had ketones.

Abstract of study comparing rates of DKA in women with type 1 diabetes who were or weren't pregnant, and, when they did go into DKA, how high their blood sugars were. The pregnant women went into DKA more often and at lower blood sugars. Average blood sugar in DKA for pregnant women was 293 mg/dl and for non-pregnant women the average blood sugar in DKA was 495 mg/dl. There was also one case of ketoacidosis in a pregnant woman without high blood sugar.

2. Starvation can cause ketoacidosis, with or without diabetes.

Case of euglycemic ketoacidosis in a type 1 diabetic who had stopped eating for two or three weeks. His blood sugar was 105 mg/dl, pH was 7.3 (mild ketoacidosis), ketones large, A1c 11.5%.

Starvation ketoacidosis in a man eating a fruit-only diet (BMI 16). His venous pH was 7.08, which means he was in moderate/severe ketoacidosis. His blood sugar was normal on admission, went into the upper 500s when he was fed, went down with insulin, stayed down without insulin. Source

Case report described as ketoacidosis in which a man eating a low carb (15grams of carbs per day) diet for three weeks was admitted to the hospital with a high blood sugar (267 mg/dl) and very slightly low pH 7.34 with ketones. He was treated for diabetic ketoacidosis. His blood sugar went normal and stayed there without more insulin. He does not meet true criteria for DKA because his pH was 7.34, and while that is low, it's not low enough to meet diagnostic criteria. His only symptom was abdominal pain.

Type 1 Diabetics are way more likely to be diagnosed with DKA, but between 5 and 20 percent of cases occur in type 2 diabetics.

Case report of ketoacidosis in a pregnant woman with type 2 diabetes. She was admitted with a pH level that was a little low (7.32) and a blood sugar of 77, but her pH level dropped to 7.23 (moderate acidosis) with a blood sugar still below 100. She had ketones.

Having blood ketones and urine ketones doesn't mean you have ketoacidosis, but a blood ketone level above 1.5 is a good reason to get it checked out

This study looked at all people coming to the ER with a blood sugar above 250, comparing those who were and weren't diagnosed with DKA, and suggesting using a blood ketone meter is better than using urine ketones for finding DKA- although DKA patients are equally likely to have high urine ketones and high blood ketones (that is, they have both urine blood ketones and high urine ketones) way more people who do not have ketoacidosis have high urine ketones, whereas most of the people who came to the emergency room with high blood ketones (about three fourths of them) had ketoacidosis. This study also makes the interesting statement that one fourth of people in the ER have diabetes. Out of the patients in the study who did have DKA, at least 10 out of the 56 had type 2 and not type 1 diabetes.

The second most common cause of ketoacidosis in the United States is alcoholic ketoacidosis, a form of alcohol withdrawal experienced by alcoholics.

My advice is that if you have diabetes, you should check your ketone levels more often if you start a new diet, are sick and vomitting, or pregnant. Especially pregnant! And if you care about somebody alcoholic or are trying to help an alcoholic sober up, encourage the person to eat something.

And now for a song (written by a medical student)

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