Case Study – Diabetic Ketoacidosis

The Case

You are returning from another call, it’s about mid-day, and you’re thinking about the leftover lunch from last day’s chicken tacos waiting for you in the fridge, when your mobile data terminal chimes in an update. Almost simulatenous your once quiet mobile radio crackles to life. “Unit fifteen respond to a six charlie one, 21 year old male difficulty breathing….” The call is surprisingly close to you and in your territory, made easier by the fact you are already exiting the interstate in the direction of the call. “Guess the chicken tacos will have to wait,” you groan as the International 4600 chassis ambulance lurches forward in response to the accelerator and your warning lights cycle to “ON” in response to the sequencer button. The electronic Q siren wails and you cut through heavy traffic to reach the call.

You arrive at a small one story house, circa 1950’s, the kind with plaster and lathe construction. The roof sags a little, but the yard is well kept. You pull on some gloves, grab your bag, and head inside. You find a 21 year old male seated on the couch just inside the door. He is heaving for breath. “He’s been doing this since last night, and throwing up a lot,” says the patient’s mother.

“So what kind of medical problems do you have?” you ask, gently sniffing the air, which smells like acetone.

“I’ve had… diabetes since… I was ten…” the patient heaves the words out. The acetone smell suddenly got stronger while he was speaking.

“I think I know what your problem is…” you comment as you reach into the practitioner’s bag of tricks and produce a glucometer. The finger stick reads only “HI” and flashes “KETONES?” at the top of the screen. “Ah ha… your blood sugar is off the chart. When did you check it last and when did you use insulin last?”

“I haven’t checked… it in a… while…” the patient pants, then promptly vomits into a nearby trash can.

“C’mon, let’s get you some help…”

Discussion

Diabetic ketoacidosis is an emergency condition that results from a shortage of insulin the the blood stream. Insulin, produced by the pancreas, is the hormone that facilitates glucose uptake by the cells of the body and signals the body to stop using fat as an energy source.

When the body fails to control the amount of insulin in the blood stream, the condition known as diabetes mellitus results. This was first described by the Ancient Greeks and roughly translated, the name means “sugar siphon.” It This disease process is divided into 3 broad categories: Type I diabetes, Type II diabetes, and Gestational Diabetes.

All forms of diabetes share polyuria as a symptom which simply means excessive urination. Other symptoms include polydipsia (excessive thirst), and polyphagia (excessive hunger). These are the body’s reactions to excessive blood glucose. The brain will attempt to signal the pancreas, which in Type I diabetics is non-functioning or functioning at diminished capacity, but there will be no response, worsening the problem. DKA is most common these patients. In Type II diabetics, the cells are insulin resistant or insensitive to it, so there can be insulin in the blood stream but the cells will not take in glucose for use. Gestational diabetes is a temporary condition as a result of pregnancy. The high blood sugar and other associated metabolic derangements results in acidosis.

The kidneys are affected by high glucose as well, and excessive urination results from an increase in the osmotic pressure in the urine as inhibits the reabsorption of water. The polydipsia results from the loss of body water and blood volume and the brain’s signal to take in more water. Other symptoms include vision changes and Kussmaul respirations, characterized as fast and deep and are a result of the body attempting to correct the acidosis by creating bicarbonate in the lungs, in order to reduce the amount of hydrogen ions in the blood stream. Left unchecked, this can cause coma from cerebral edema, cardiac dysrhythmias from acidosis, and death. Nausea and vomiting, abdominal pain, altered mental status (coma), and dehydration are all symptoms that should prompt a blood glucose analysis.

So how do we treat DKA in the field? Very few systems carry insulin, or will be able to titrate it to achieve the necessary effect. We should focus our treatments on body fluid replacement and in cases of cardiac arrest, reversal of acidosis using sodium bicarbonate. IV therapy is the best route, and it will be a slow action even though we may be pouring fluids into them. In cases of extreme DKA two lines are best, as these patients will need circulatory support to replace lost volume. When you get to the hospital, they will most likely use insulin to bring the blood glucose down to a normal level. In cases where the patient is unconscious, intubation is indicated (or appropriate airway management like OPA/NPA, BIAD, etc) and ventilation in necessary. Ventilation should be titraed using capnography in order to avoid further cerebral edema by hyperventilation.

Conclusion

The patient ambulates to your cot, and you get him in the ambulance quickly. You initiate IV access and begin a large normal saline bolus as you transport to the hospital. You monitor the patient en route and continually recheck the blood sugar en route, not much difference is made as it still reads “HI” and flashes “KETONES?” On arrival at the hospital, the patient states he feels a little better. You find out later he was admitted for observation and discharged a few days later.

Resources

http://www.medterms.com/script/main/art.asp?articlekey=11148

http://en.wikipedia.org/wiki/Diabetic_ketoacidosis

http://en.wikipedia.org/wiki/Diabetes_mellitus

http://en.wikipedia.org/wiki/Metabolic_acidosis