A team including an attending endocrinologist, two nurse practitioners, and a certified diabetes educator are alerted when a patient is enrolled into the protocol.
Patients with all forms of DKA, including mild DKA without an anion gap, are managed on insulin drip with an endpoint goal of reaching a bicarbonate level of 21 mEq/L.
"The decision [to keep the patient in the ED for further observation and treatment or admit to the ICU] is based on the severity of the DKA and/or existing concurrent medical illness. If admitted to the ICU, the patient remains in the ICU arm of the DKA protocol, which involves frequent monitoring of glucose, electrolytes, venous blood gas, and urine output. Treatment is aimed at correcting the DKA and associated electrolyte disturbances," explained Maria Koen, a nurse practitioner and certified diabetes educator at Joslin Diabetes Center.
Regardless of whether the patient is admitted or remains in the ED, treatment involves the same IV insulin algorithm, which calls for no initial bolus; the starting rate is based on the initial finger stick, Ms. Koen noted.
Other features of the protocol include hourly finger sticks with adjustment of the dose with a goal of a target blood glucose of 100-180 mg/dL. Every 3 hours, someone on the team assesses venous blood gas and electrolytes.
IV fluid is run concurrently with IV insulin. Once the glucose drops to less than 250 mg/dL, fluid is changed to 5% dextrose in normal saline (D5NS). Once glucose increases again to 250 mg/dL, the protocol calls for discontinuation of D5NS with continuation of IV insulin infusion until the acidosis resolves.
If severe hypoglycemia occurs, D50 (50% dextrose) can be given as a bolus to reach the target of 100-180 mg/dL. The insulin drip is then resumed at 50% of the rate prior to the hypoglycemic event.
"Generally, we use normal saline or lactated Ringer’s as a first choice for IV fluid, at a rate of approximately 1 liter an hour for the first 4 hours, and this may be adjusted for patients who are at risk for volume overload, such as elders or patients with chronic kidney disease or congestive heart failure," she said.
After the first 4 hours, the IV solution may be changed to half of the normal saline, or half of the D5, if blood glucose drops below 250 mg/dL, at a rate of 125-250 cc per hour.
IV fluids may also be discontinued at this point if the patient is able to tolerate oral fluids.
The protocol also calls for electrolyte repletion as needed. Potassium may be added to each liter of IV fluid if the serum potassium reaches less than 5 mEq/L and the patient is voiding. The amount added is at the discretion of the attending physician, Ms. Koen said.
"Keep in mind that as the acidosis resolves, serum potassium will decrease. In such events, if severe hypokalemia occurs, it may be necessary to either decrease the insulin rate or temporarily hold the IV insulin drip," she said, noting that oral potassium and IV or oral phosphate can also be given once a patient can tolerate oral intake.
Insulin pumps should be removed to avoid overlap with the IV insulin, and the team should assess pump function and self-management.
Urine output and ability to tolerate oral intake should be assessed throughout the protocol, and patients should eat as soon as they are able to tolerate oral intake. The team should assess clinical status every 4 hours.
The patients’ care can move beyond the strictures of the protocol once they are either admitted to the ICU or stabilized in the ED. Those not admitted to the ICU can be discharged to home once their anion gap closes, their bicarbonate reaches more than 20 mEq/L, they can tolerate oral intake, and they successfully transition to a subcutaneous insulin regimen.
The transition to subcutaneous insulin requires that the basal dose be determined based on the patient’s home long-acting insulin dose or adjusted based on the nurse practitioner’s or doctor’s recommendations. Dosing for patients who are newly diagnosed or insulin naïve is calculated based on body weight in kilograms x 0.2.
When the patient is able to tolerate oral intake, prandial subcutaneous insulin based on the home prandial insulin dose should be initiated. Dosing in those who are insulin naïve should be based on body weight in kilograms x 0.2 and divided by 3 (but only with team recommendation).
"When transitioning from the IV insulin drip to subcutaneous insulin, if only basal insulin is given we recommend an overlap of the IV insulin drip for 2 hours. If both basal and prandial insulin are given at the same time, the recommendation is to overlap the insulin drip for at least 1 hour, and then the drip may be turned off," Ms. Koen said.