A 68 y/o female patient is s/p CABG surgery two weeks ago. She is found unresponsive after having a generalized seizure. Her medical history is unremarkable. Her hospital course to date was complicated by ventilator-acquired pneumonia, right hemispheric stroke, clinically significant GI bleeding, and acute tubular necrosis requiring hemodialysis. During rounds this morning, the patient looked well and told the team she 'felt good' for the first time. She has an arterial line to measure blood pressure, requiring heparin flushes every shift. Other meds include sliding scale insulin, labetolol 200mg po BID for HTN, omeprazole 20mg po QD, and zolpidem 10mg po QHS prn sleep.

The ICU team arrives almost immediately and works on controlling the seizure with IV lorazepam and midazolam after intubating the patient emergently to protect her airway. Her ABG and serum electrolytes look normal except a slightly low K+.

What might have precipitated the seizure? How would you go about treating the patient?

A picture in the article shows how a multitude of multi-dose vials were on the patient's bedside cart. (see attached).

To try to complete the story briefly, the patient was given 100mg thiamine, 50% dextrose ampules IV. She received five 50ml amps of 50% dextrose over the next 4 hours. These only raised her blood glucose from "undetectable" (according to the lab) to 55 mg/dL. She patient lapsed into a coma. After 7 weeks, the family decided to withdraw life support and the patient expired.

I don't want to go through the entire root cause analysis since it's detailed in the article. There is a LOT of good information and background in the article and I'd encourage everyone to read the article. A couple of points to bring out - there's two primary classes of errors - slips and mistakes. Slips occur during low-level, semiautomatic functions (i.e every shift flushes of IV lines). Mistakes involve higher cognitive function and occur in new or non-stereotypical situations. This was a slip. "Humans are not perfectible."

Some fixes implemented by the hospital include:

1)      Insulin was added to the automated dispensing device.

2)      All staff obtaining meds from ward stock were instructed to keep meds secured in authorized locations (vice the bedside cart)

3)      All nurses reminded to keep med carts locked when not attended.

4)      Multidose vials of heparin and insulin were prohibited.

5)      Use of normal saline (instead of heparin) was required for patency of arterial lines.

6)      Interdisciplinary teams established to examine how to deliver meds quickly without compromising safety or optimum medication practices.

A couple of points - when giving thiamine and glucose to an unresponsive patient, be sure to give the thiamine first. If the patient has been on a carbohydrate only diet (i.e. alcohol) the metabolic system is already stressed and adding more carbohydrate to the already stressed system may precipitate Wernicke's encephalopathy or the just makes things worse. Another agent to consider is naloxone. These things may end up being diagnostic as well as therapeutic.

A useful acronym I learned from Dr Charlie Reasoner (UTHSCSA) for potential causes of HYPOglycemia is:

E - Exogenous agent - insulin, oral agents (to include sulfonylureas, quinine, salicylates, pentamidine, TMP-SMX)

X - Exogenous agent - insulin, oral agents

P - Pituitary - panhypopituitarism

L - Liver - liver failure

A - Addison's disease

I - Insulinoma

N - Neoplasm - certain tumors produce insulin like growth factor II