Hypoglycemia and Asystole

Scrabbler · Mar 25, 2008

[color=#003399]refer to your acls books on the h's and t's (causes of arrest)

[color=#003399]hypoglcemia or [color=#003399]hyperglycemia- low blood glucose from overdose of [color=#003399]oral hypoglycemics such as [color=#003399]sulfonylureas, or overdose of [color=#003399]insulin. rare endocrine disorders can also cause unexpected hypoglycemia. generally, hyperglycemia is itself not fatal, however [color=#003399]dka will cause ph to drop, and [color=#003399]nonketotic hyperosmolar coma leads to a severely hypovolemic state. hypoglycemia is corrected rapidly by intravenous administration of concentrated glucose (typically 25 ml of 50% glucose in adults, but in children 25% glucose is used, and in neonates 10% glucose is used.) however, the patient will often require a continuous intravenous drip until the causative agent is completely metabolized. in dka, the goal is correction of acidosis. in nkh, the goal is adequate fluid resuscitation. (taken from acls blurb online)

TiredMD · Mar 25, 2008

i have a question for anyone who knows the answer. i know that hypoglycemia can cause asystole, but does anybody know why or how it does? thanks!!

this is a really interesting question, and prompted me to go back through some of my cardiology textbooks (which i hate hate hate). my intuitive answer was going to be something along the lines of, "glucose is utilized by cells to produce atp, which is required for muscular contraction to occur."

but then i ran across a couple things that muddied the issue in my mind:

1) cardiac muscle preferentially takes up fatty acids and oxidizes them to produce atp. in times of stress, glucose and glycogen are increasingly utilized, but the core fuel source for the heart is fatty acids, not glucose.

2) in contrast, the brain is dependent almost exclusively on glucose. no glucose, no brain activity.

3) cardiac muscle basically cannot function anaerobically. no oxygen, no heartbeat. in times of extreme stress, it is likely that metabolism is switching from aerobic to anaerobic metabolism, but i don't understand if the heart would actually be oxygen deprived, since these people are usually breathing hard up to the end.

i couldn't find any direct answer to your question, but i suspect in the end that it really is an atp issue. it is my bet that other areas of the body are using up much of the available circulating fats in periods of hypoglycemia. without the glucose load normally available, your body can't release extra glycogen and fat stores fast enough to support metabolism. and cardiac muscle, unlike most other organs, does not have the option of partially or temporarily shutting down to conserve energy.

of course, that's just a guess.

good question.

Ivanna_Nurse, BSN, RN · Mar 25, 2008

I hope that someone comes up with some info too. Actually, we have a pt on the unit that is bradycardic and has periods of standstill. The dr was trying to correlate glucose with the occurrence... I forgot about the H's and T's!

nurturing_angel · Mar 26, 2008

I don't know why it happens but I know that I (as a heart pt and a diabetic) let my blood sugar get too low, I have chest pain and pressure. I do have cardiac artery spasms too. My doc couldn't explain it to me but he did say there was a correlation between chest pain and low blood sugar and I had to be careful about it. This is scary!

:saint:

GilaRRT · Mar 26, 2008

I am not sure you can say that hypoglycemia is a common or even uncommon cause of asystole. I have seen hypoglycemia and asystole coexist; however, other factors in addition to asystole did exist in every case. Massive MI, trauma, drug overdose, etc.

Hypoglycemia that is left untreated will eventually cause masive cerebral insult. Eventually, this will filter down to other body systems and the patient will experience global insult and collapse of his/her body systems. The eventual outcome will be asystole. However, I suspect most patients who present in asystole will not have isolated hypoglycemia as the cause of their asystole.

The five H's and T's are correctable conditions that we are able to treat in some cases. So, hypoglycemia should only be a small part of the puzzle to consider when we have a patient in asystole. Remember, asystole is usually an ominous finding associated with poor outcomes in most cases of arrest.

Research does seem to indicate that poor glycemic control in critically ill patients does in fact lead to more negative outcomes; however, glycemic control is only one part to managing a critically ill patient.

Even more interesting, are case reports of critically ill patients developing cardiac stand still after rapid administration of IV dextrose. The underlying pathology seems to be related to severe hyperkalemia that is related to the admin of dextrose. (concentrated) Very strang, since dextrose is associated with decreased levels of serum potassium. Hence, it is one of the medications used in the treatment of hyperkalemia.

Ni_Ni · Apr 1, 2008

Thanks to everyone for the information!!