From the Forrest County Coroner's Office, Hattiesburg, Mississippi (B.B.); Hattiesburg Police Department, Hattiesburg, Mississippi (R.K.); and Cardiothoracic Surgery and Surgical Critical Care, Enid, Oklahoma (F.C.S.).
Manuscript received November 18, 2003; accepted November 26, 2003.
Reprints: F. Clark Sauls, MD, FACS, 330 S. 5th Street, Suite 104, Enid, OK 73701. E-mail: email@example.com.
Microprocessor-controlled insulin pumps designed for continuous delivery of short-acting insulin analogs into subcutaneous tissues offer several important potential benefits for diabetic patients. The delivery of other substances using these systems is technically feasible. We present a case of homicide involving lethal doses of etomidate and atracurium injected via the victim's insulin pump. This unique situation could be encountered by homicide investigators more frequently as the popularity of these systems continues to grow.
Insulin pumps that provide continuous delivery of insulin subcutaneously have proven to be beneficial for selected diabetic patients.1,2 These microprocessor-controlled devices permit precise control of the rate of insulin administration and allow patients more flexibility, avoidance of multiple insulin injections, and better overall control of their glucose levels. It is believed that approximately 6.9% of the US population is diabetic and that this figure is increasing.3 It is reasonable, therefore, to anticipate that the number of people utilizing insulin pumps will continue to increase in the foreseeable future. We report a case wherein an insulin pump was used to administer a lethal dose of medications in a homicide. It is the only such incident of which we are aware, and there are no others presently known to the company (personal communication, Mrs. Gail Fant, Medtronic Minimed).
Ambulance service personnel responded to a 911 call received from the home of a 59-year-old cardiac surgeon. They determined that the physician was dead and notified the county coroner. Upon arrival, the coroner and his deputy found the decedent's widow in bed with the body. After speaking briefly with the coroner, her first action was to remove the insulin reservoir, tubing and battery from the pump and discard them. Citing the cost of the device (approximately $5000) she stated her intention to donate the pump to some other patient.
Information about the victim's medical history was obtained both from the widow and the victim's personal physician, who was interviewed by telephone. The decedent had undergone extensive treatment of hepatitis C over several years and was currently on a waiting list for a liver transplant. He stopped operating approximately 10 months before and had been considered disabled since that time. He also had type II diabetes mellitus and used a blue Medtronic MiniMed 508 (serial number 73197-20E3) insulin pump to control blood glucose. In view of his history, a natural cause of death was presumed initially. However, consistent with coroner's office policy, a blood sample was drawn and submitted immediately for routine drug and toxicological screens. The widow was unaware of this since the samples were taken after the body was removed.
Three weeks later, the widow contacted the coroner to inquire about a death certificate and was assured that this would be issued immediately upon receiving the test results that were still pending. She was stunned to learn that blood samples had been taken. Shortly thereafter, the report was received and indicated the presence of caffeine, hydroxyzine, promethazine, metoclopramide, and etomidate. All of these substances were consistent with the victim's medical regimen and lifestyle, except etomidate (Amidate; Abbott Pharmaceutical, Abbott Park, IL). The presence of this anesthetic induction agent could not be explained, and the widow denied any knowledge of the drug. The body was subsequently exhumed and a forensic autopsy performed. This confirmed the presence of etomidate in liver tissue at a concentration of 618 ng/g. Also discovered was the presence of laudanosine in liver (17,000 ng/g), skin (2600 ng/g), fat (1100 ng/g), and muscle (5000 ng/g). Laudanosine is the major metabolite of atracurium (Tracrium; GlaxoSmithKline Inc., Research Triangle Park, NC), a neuromuscular blocking agent also commonly used in clinical anesthesia practice.4 Other breakdown products including the quaternary acid and quaternary alcohol were also found in very high concentrations in multiple tissues.5,6 By contrast, in a reported case of suicide involving this drug, a level of 380 ng/g was found in liver tissue.7 The autopsy also disclosed micronodular cirrhosis, portal fibrosis, and regenerative nodules in liver sections consistent with the victim's medical history but concluded that the cause of death was “laudanosine overdose and etomidate toxicity.” Law enforcement authorities then initiated a criminal death investigation that culminated in the arrest and subsequent conviction of the widow for murder.
The widow was a registered nurse who worked in the recovery room and endoscopy suite of a nearby hospital where these drugs were readily available. A local diabetic educator confirmed that the widow was familiar with the operation of the victim's insulin pump. The nanny employed by the couple testified that the widow often changed insulin infusion sets for the doctor. A financial motive was present and later demonstrable at trial. Finally, the widow confided her actions in administering the drugs via the insulin pump to a friend who testified to that. Her action in removing the reservoir and battery from the pump served to conceal the poisoning at the time of the victim's death. (Data stored in the pump's microprocessor memory are lost after approximately 2 hours without battery power.)
This case demonstrates that the administration of other substances via an insulin pump is feasible. Unexpected death of a subject with such a system should prompt investigators to secure the pump complete with its reservoir and tubing set. Reviewing data contained in the pump's memory may prove helpful and, in such instances, the unlikely possibility of a pump malfunction might also be considered. Investigators should be aware that the Medtronic system is supplied with a remote control device suitable for mounting on a key ring. Although many users don't carry or use their remote, it may be possible for another person to change the rate of insulin administration using the remote device.
Presently, there are 4 manufacturers whose systems are approved for use in the United States: Medtronic Minimed (Northridge, CA; http://www.minimed.com; 800-826-2099), Disetronic Medical Systems, Inc. (800-280-7801; http://www.disetronic.com; e-mail: firstname.lastname@example.org), Animas Corporation (Frasier, PA; http://www.animascorp.com), and Deltec (St. Paul, MN). Unless the investigator is familiar with these devices, the assistance of a diabetic educator versed in the operation of the pump is recommended.
Diabetes appears to be increasing in prevalence. As the popularity of these systems continues to increase among patients with diabetes, their misuse and involvement in homicides and/or suicides may also become more prevalent.
The authors thank Mrs. Gail Fant of Medtronic Minimed for her assistance with details of pump operation.
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2. Saaddine JB, Engelgau MM, Beckles GL, et al. A diabetes report card for the United States: quality of care in the 1990s. Ann Intern Med
3. Venkat KM, Boyle JP, Thompson TJ, et al. Lifetime risk for diabetes mellitus in the United States. JAMA
4. Hughes R. Atracurium: an overview. Br J Anaesth
5. Nigrovic V, Auen M, Wajskol A. Enzymatic hydrolysis of atracurium in vivo. Anesthesiology
6. Bion JF, Bowden MI, et al. Atracurium infusions in patients with fulminant hepatic failure awaiting liver transplantation. Intensive Care Med
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