Physician ordered iv insulin 3 unit/hour, solution contain 50 unit insulin in 100 ml dextrose how many ml of solution is infused per hour
Answers
Problem: We are aware of numerous reports of serious errors associated with the misadministration of insulin. These events have involved various types of practitioners, including physician house officers (HOs), nurses, and a pharmacist. Human error (e.g., mental slips, lapses, forgetfulness) associated with insulin dose measurement and hyperkalemia treatment was the predominant proximate cause of these events; most of the human errors were associated with knowledge deficits regarding insulin concentration (specifically that “U-100” means the concentration is 100 units per mL), the differences between insulin syringes and other parenteral syringes, and a perceived urgency with treating hyperkalemia.
In the most recent event, a physician ordered intravenous (IV) dextrose 50% injection (50 mL) along with 4 units of regular insulin IV (U-100) for a patient with renal failure and severe hyperkalemia. However, a nurse drew 4 mL (400 units) of insulin into a 10-mL syringe and administered the dose IV. The patient became severely hypoglycemic and had to be transferred to a critical care unit for treatment and monitoring.
In another case, a nurse accidentally added 50 units of regular insulin to an existing IV infusion instead of 5 units. A physician had asked the nurse to add 5 units to the IV bag. The nurse felt the half-inch insulin needle on an insulin syringe was not long enough to insert into the IV bag. Thus, the nurse drew the insulin into a 3-mL syringe with a longer needle. However, she accidentally withdrew 0.5 mL (50 units) of insulin instead of the correct volume of 0.05 mL (5 units). She quickly showed the prepared dose to another nurse, who also failed to pick up the error. Later, the nurse recognized her error while preparing a subcutaneous insulin dose for another patient using a U-100 insulin syringe.
A third case involved the incorrect preparation of an insulin infusion. While the pharmacy was closed, a physician ordered an IV insulin infusion for a patient. Near the end of her shift, a new graduate nurse was asked to prepare a “1:1” insulin infusion (1 unit/mL). An experienced nurse who checked the solution failed to notice that the graduate nurse had drawn 10 mL (1,000 units) of insulin into a 10-mL syringe, instead of 1 mL (100 units) in an insulin syringe, and then added that amount to a 100-mL bag of 0.9% sodium chloride. This resulted in a 10-units/mL insulin infusion. Several hours later, both nurses—by then at home—independently called the hospital because they were worried that “something was not right” with the insulin infusion. When the error was discovered, the patient had already received 160 units of insulin over several hours instead of the prescribed 16 units. The patient’s blood glucose level dropped as low as 13 mg/dL. He was treated and experienced no additional adverse effects.
A similar event was reported in which a pharmacist prepared an insulin infusion in a 10-units/mL concentration instead of the required 1-unit/mL concentration. It is not unusual to prepare an admixture or dose using half of a vial or more when dealing with other medications that typically come in multiple-use vials. Thus, staff may not find it odd to use half of a vial or more to prepare an insulin infusion, particularly if they are busy, distracted, or preoccupied. But a 10-mL multiple-dose vial of insulin can essentially contain up to 100 doses or more.
We also recently became aware of a case in which orders were given for a patient with hyperkalemia to receive insulin and a 50% dextrose injection, but the patient received only the insulin portion of the treatment and experienced significant hypoglycemia.
In several other recent events reported to us from other countries, physicians were involved in insulin administration errors. In one case, 10 units of insulin was prescribed, but a medical staff HO inadvertently administered 100 units of insulin using a regular parenteral syringe. In a second case, a HO administer