Your first patient of the morning is a 19-year-old college student. Her roommate talked her into coming to the emergency department (ED) because the patient is worried that she may have been raped. She remembers being at a fraternity party with some friends the night before. She awoke this morning in an unfamiliar room with her clothing in disarray. While awaiting the arrival of the forensic nurse examiner, the patient’s nurse asks if you need urine and blood samples.
Most sexual assaults, particularly among young women, are committed by an acquaintance or former intimate partner. Many of these assaults are facilitated by “date rape drugs,” which may lower the victim’s inhibitions, render the victim unable to resist, and/or impair memory.
These drugs, of which alcohol is by far the most common, may be either voluntarily consumed by the victim or surreptitiously given to the victim. The prevalence of drug-facilitated sexual assault (DFSA) is difficult to determine, in part because of underreporting. Many date rape drugs are detectable in blood or urine only for a short time; therefore, it is important for emergency physicians to recognize and know how to evaluate patients who have experienced DFSA.1
Although there is a perception that DFSA is a premeditated crime, it is more often a crime of opportunity. Voluntary consumption of substances, most commonly alcohol and cannabis, most frequently precedes DFSA.2 Prescription drugs such as anxiolytics, sleep aids, and muscle relaxers are frequently used. Less often, date rape drugs such as gamma-hydroxybutyrate, Rohypnol, ecstasy, or ketamine are used; these drugs may easily be hidden in alcoholic beverages.
Of note, Rohypnol is not legally available in the United States. Over-the-counter medications including diphenhydramine, and tetrahydrozoline (found in over-the-counter eye drops) have also been implicated in DFSA.
The clinical presentation of patients who have experienced DFSA varies depending upon the drug used and the time between the event and ED presentation. Patients may be uncertain whether they have been sexually assaulted. Common presentations include altered mental status, memory loss, impaired speech or coordination, vomiting, or a state of intoxication that is out of proportion the amount of alcohol consumed. Patients may have sustained injuries for which they have no explanation. Often, patients present because they woke in an unfamiliar place or with disheveled clothing.
As many date rape drugs have short half-lives, rapid collection of blood and urine is key for evidentiary purposes. Some jurisdictions use hair sampling, especially if there is a significant time gap between consumption and collection.3 Protocols for DFSA testing vary among jurisdictions. In some states, blood needs to be collected within 24 hours and urine within 120 hours, although the likelihood of detection decreases with time.
If possible, the patient’s first void after the assault should be collected and refrigerated, and a blood sample should be drawn into a gray-top tube. The blood and urine samples are generally sent to the crime lab for processing.
There is controversy around the analysis of specimens for DFSA. Usual hospital-based drug testing is not appropriate for testing in DFSA. These tests do not capture many of the substances used and most hospital laboratories are not forensic laboratory accredited, making the results inadmissible in a court of law. Specimens from suspected DFSA need to be analyzed in a state crime lab or forensic reference laboratory that uses immunoassays to detect drug classes and gas chromatography, liquid chromatography, or headspace gas chromatography to verify and identify specific substances with high accuracy. These labs are accredited so that the results are admissible in court and have policies and procedures in place to maintain the chain of custody of the specimens.
The patient has not yet urinated, and she is given a sterile cup in which to do so. A gray top tube is drawn along with other bloodwork and sent to the state crime lab. The forensic nurse examiner collects the patient’s clothing and other evidence; these are turned over to local police, maintaining chain of custody. The patient is provided with prophylaxis following the sexual assault .
Dr. Rozzi is an emergency physician, medical director of the Forensic Examiner Team at WellSpan York Hospital in York, Pennsylvania, and secretary of ACEP’s Forensic Section.
Dr. Riviello is chair of emergency medicine at Crozer-Keystone Health System and medical director of the Philadelphia Sexual Assault Response Center.
- U.S. Department of Justice, Office on Violence Against Women. A National Protocol for Sexual Assault Medical Forensic Examinations(2nd ed.). 2013.
- Hurley M, Parker H, Wells DL. The epidemiology of drug facilitated assault. J Clin Forensic Med. 2006;13(4):181-185.
- LeBeau MA, Andolla W, Hearn WL, et al. Recommendations for toxicological investigations of drug-facilitated sexual assaults. J Forensic Sci.1999;44(2):227–230.
