Saturday, June 09, 2007


so i've got a lot of cross-cover in the picu this month.

cross-cover is when you are on-call at night for a service that you are not rotating on that month. in the picu, this can be a bit dicey, as the kids can be quite sick (obviously) and you don't really know them. we have a 10-bed picu. compared to some hospitals, that's pretty small. so, you think, how bad could it really be, right? well, it can be bad. especially as our attendings are not in-house and you are basically on your own. Thank god for picu nurses.

i blogged about my first cross-cover this month in a recent post.

last night wasn't as bad, but it still freaked me out and i didn't leave the unit.

i managed 9 kids, 4 of whom are on vents, 1 of whom was the first kid i'd ever managed with DKA, or diabetic ketoacidosis.

DKA is how many children present when they are first diagnosed with type I diabetes, which is the type associated with autoimmune destruction of the pancreas and, thus, endogenous insulin production.
Normally, when you eat food, your body breaks it down into smaller parts, including glucose from carbohydrates. When glucose levels in your blood rise, this triggers your pancreatic cells (see diagram below) that make insulin (the islets of Langerhans) to secrete insulin. your liver, fat and muscle cells need insulin in order to use glucose for energy.

In type I diabetes, the islets of Langerhans have been destroyed by autoantibodies. So you can't release insulin in response to elevated blood glucose levels.
when glucose builds up in your bloodstream, that's bad. in order to keep your brain going, your body starts to use fat to make energy, resulting in the formation of ketone bodies (the keto- in ketoacidosis). these use up your buffers, resulting in acidosis. the elevated blood glucose results in an osmotic diuresis. a typical patient with DKA is about 7-10% dehydrated as a result. dehydrated and essentially starving. this kid had lost 15lbs in 3 weeks.

in a purely abstract way, it's sort of fun to manage these patients. i'm an orderly person. i like things that are predictable, things that make sense. when you are reversing the acidosis of a kid with DKA, it's orderly, predictable. the glucose falls, the pH corrects, the sodium rises, the potassium falls. usually the phosphate falls, too. you can anticipate all these things, plan for them. hourly labs. data sheets to track your progress.

in a not so abstract way, it's not so fun to manage these kids. they're scared. sometimes they are super sick. they are getting poked hourly for blood. their life is changing and they feel completely out of control. from a doctor's perspective, you are scared to death that they will get one of the dreaded complications of DKA, cerebral edema, so you're constantly checking their mental status to make sure they are not deteriorating. i kept asking this kid's nurse to wake her up and see if she had to pee. she didn't. and i think i just ended up annoying my nurse. good thing he likes me and just thinks i'm funny when i get all paranoid.

this kid did really well. no cerebral edema. by 4am, her glucose was normal again, her serum ketones were almost cleared. she didn't have horrible sodium or potassium derangements. her acidosis had corrected.

all was well in terms of her physiologic state.

she has a long road ahead of her, but she strikes me as one of those mature-for-her-age kids who will do just fine.

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