Rationale:

• Bedside urine β-HCG testing is obtained in all women patients of childbearing age to exclude preexisting pregnancy before consideration of pregnancy and STD prophylaxis.
• Urine, blood, or both may be requested by local crime labs for toxicology testing.
• Crime labs request the patient's first available voided urine to optimize recovery of potential substances.
• Perpetrator use of alcohol and other drugs to incapacitate victims and facilitate rape ("drug-facilitated sexual assault" [DFSA]) has increased in recent years.
• Although any type of sedative or hypnotic may be used to facilitate sexual assault, the most notable drugs recently described include flunitrazepam and GHB.

Evidence:

• Reliable tests can be done on reference samples for the patient's DNA. Two review compilations of crime lab validations studies from sexual assault cases have shown the robustness of DNA tests currently used in forensic casework (44; 45).
• A 6-year, retrospective, emergency department case review of 1421 patients found that reported drug-facilitated sexual assault comprised 12% of cases, with large increases over the period studied. Compared to other sexual assaults, suspected drug-facilitated sexual assault cases have a longer delay in presenting to the hospital, are less likely to involve the police, and have a lower occurrence of both genital and extra-genital injury (46).
• Obtaining the first voided urine is particularly important when GHB is the substance suspected in drug-facilitated rape, as a study had shown that peak urine concentration after single-dose ingestion of 50 mg/kg occurs within 3 hours after ingestion and may be undetectable by 12 hours post ingestion. Larger doses and illegally manufactured GHB may follow different pharmacokinetics (47).
• Commonly used urine and blood toxicology tests for GHB have been shown to be reliable, sensitive, and specific in two crime lab experimental analyses (48; 49). Half of all sexual assaults involve intake of drugs or alcohol by the patient (50).
• In a prospective, observational study, current lab methods detected flunitrazepam and its metabolites in urine 5 days or more after a single-dose drug intake in all 21 test subjects (51).

Comments:

• None.