There are similarities and differences between these 3 conditions which all carry treatment implications. Each mimic the “Starved state” where Glucagon easily outweighs Insulin. Glucagon stimulates the breakdown of glycogen stores in the liver along with Gluconeogenesis to maintain blood glucose. It also stimulates Lipolysis, which mobilizes fatty acids for beta-oxidation in the liver to produce Acetoacetic acid, a ketoacid that is also converted to beta hydroxybutyrate (BHB). Therefore, in all 3 conditions, serum BHB has limited utility in differentiation.
In Starvation Ketosis (SK), acidosis is very mild if at all present. Ketoacids stimulate the pancreas to release Insulin which is enough to keep Lipolysis in check. In Alcoholic Ketoacidosis (AK) we commonly encounter patients who are severely volume depleted and in withdrawal which drastically elevates the stress level along with circulating stress hormones that work synergistically with Glucagon to overwhelm Insulin. This leads to massive production of Ketoacids like BHB. But we also have Lactic Acidosis as well. Recall, NAD+ is a cofactor used to convert Pyruvate to Acetyl-CoA in the TCA cycle. The metabolism of Alcohol depletes NAD+ yielding NADH instead, a cofactor used to convert Pyruvate to Lactate! Patients with AK may, therefore, present with severe acidosis. NAD+ is also a cofactor for Gluconeogenesis which is why patients may also present with Hypoglycemia. In both SK and AK, feed them or give IV dextrose, give thiamine, and watch out for Refeeding Syndrome. If Hyperglycemic, avoid Insulin drips unless also diabetic as you risk causing Hypoglycemia once the Insulin/Glucagon balance normalizes.
In both conditions, low levels of circulating Insulin and Ketoacid-induced Insulin release are typically enough to prevent blood glucose > 250 mg/dl or Glucosuria. DKA is essentially a state of NO Insulin; the actions of Glucagon are completely unmitigated, and this leads to severe ketoacidosis, Hyperglycemia > 250 mg/dl and Glucosuria. Treat with Insulin, provided the starting potassium is appropriate to do so.
#diagnosis #differential #algorithm #management #treatment #criticalcare #foamed
Obiajulu Anozie
@icuexplained
· 4 years ago
