Validation of a rapid urine screening assay for cocaine use among pregnant emergency patients

Identification of polysubstance abuse in the parturient

Illicit drugs are widely used by inner city patients and their use by pregnant women has increased in recent years. The aim of this study was to determine the prevalence of polysubstance abuse among parturients at our institution who received no prenatal care ('unbooked') and to determine the accuracy of the Ontrak TesTcup an in vitro immunodiagnostic assay. We prospectively analysed urine from 50 'unbooked' parturients and found that 26 (52%) tested positive for cocaine. Of these, six patients (23%) were also positive for morphine. All TesTcup results were confirmed by the hospital laboratory using alternate chemical methods. When comparing TesTcup to the hospital laboratory, there were no false positive or negative results. Given the high frequency of concomitant opioid abuse in cocaine-abusing parturients, anyone suspected of cocaine abuse should be tested for other illicit substances. TesTcup is a clinically accurate test that allows the rapid assessment of several drugs of abuse, which may impact on anaesthetic care.

Fetal effects of cocaine: an updated meta-analysis

BACKGROUND

A very large number of women in the reproductive age group consume cocaine, leading to grave concerns regarding the long term health of millions of children after in utero exposure. The results of controlled studies have been contradictory, leading to confusion, and, possible, misinformation and misperception of teratogenic risk.

OBJECTIVE

To systematically review available data on pregnancy outcome when the mother consumed cocaine.

METHODS

A meta-analysis of all epidemiologic studies based on a priori criteria was conducted. Comparisons of adverse events in subgroups of exposed vs. unexposed children were performed. Analyses were based on several exposure groups: mainly cocaine, cocaine plus polydrug, polydrug but no cocaine, and drug free.

RESULTS

Thirty three studies met our inclusion criteria. For all end points of interest (rates of major malformations, low birth weight, prematurity, placental abruption, premature rupture of membrane [PROM], and mean birth weight, length and head circumference), cocaine-exposed infants had higher risks than children of women not exposed to any drug. However, most of these adverse effects were nullified when cocaine exposed children were compared to children exposed to polydrug but no cocaine. Only the risk of placental abruption and premature rupture of membranes were statistically associated with cocaine use itself.

CONCLUSIONS

Many of the perinatal adverse effects commonly attributed to cocaine may be caused by the multiple confounders that can occur in a cocaine using mother. Only the risk for placental abruption and PROM could be statistically related to cocaine. For other adverse effects, additional studies will be needed to ensure adequate statistical power.

Screening for stimulant use in adult emergency department seizure patients

OBJECTIVE

The objective of this study was to determine the prevalence of positive plasma drug screening for cocaine or amphetamine in adult emergency department seizure patients.

METHODS

This prospective study evaluated consecutive eligible seizure patients who had a plasma sample collected as part of their clinical evaluation. Plasma was tested for amphetamine and the cocaine metabolite benzoylecgonine using enzyme-mediated immunoassay methodology. Plasma samples with benzoylecgonine greater than 150 ng/mL or an amphetamine greater than 500 ng/mL were defined as positive. Patient demographics, history of underlying drug or alcohol-related seizure disorder, estimated time from seizure to sample collection, history or suspicion of cocaine or amphetamine abuse, results of clinical urine testing for drugs of abuse, and assay results were recorded without patient identifiers.

RESULTS

Fourteen of 248 (5.6%, 95% CI 2.7%-8.5%) plasma samples were positive by immunoassay testing for benzoylecgonine and no samples (0%, 95% CI 0-1.2%) were positive for amphetamine. Positive test results were more common in patient visits where there was a history or suspicion of cocaine or amphetamine abuse (p < 0.0005).

CONCLUSIONS

During this study period, routine plasma screening for cocaine and amphetamines in adult seizure patients had a low yield. As a result, routine plasma screening would yield few cases of stimulant drug in which there was neither a history nor suspicion of drug abuse in this population.

Bedside diagnostic testing of body fluids

Numerous bedside diagnostic modalities are appropriate for the practice of emergency medicine. The proliferation of sophisticated technology is likely to increase both the availability and accuracy of commercial testing products. If health care reform in the United States results in a relaxation of the CLIA regulations, there will be a rapid expansion of research and development aimed at the biotechnology market. How much this would pertain to hospital-based emergency practice remains to be seen. Cost containment pressures may act in both directions on the utilization of available bedside technology. Although these tests are often less expensive than centralized laboratory determinations, the ready availability of near-patient testing may result in an increase in use that negates the lower cost. As with other diagnostic modalities, a thoughtful, considered approach based on scientific evidence will be necessary to formulate the appropriate use of bedside testing in individual emergency practice settings.

Cocaine screening of parturients without prenatal care: an evaluation of a rapid screening assay

Illicit drugs are used widely by inner city patients in our society. Because cocaine ingestion can produce life-threatening arrhythmias and interact with anesthetic drugs, it is potentially useful for the anesthesiologist to know a high-risk patient's cocaine status before administering anesthesia. The commonly used methods to detect cocaine abuse, however, often require 1-3 days for laboratory processing. With these tests, anesthesiologists are unable to test for recent cocaine use in an emergency setting. A new rapid latex agglutination assay for urinary metabolites of cocaine (OnTrak Abuscreen; Roche Diagnostic Systems Inc., Branchburg, NJ) was compared with an assay used by many hospital laboratories. The prevalence of cocaine abuse in the group of unregistered parturients was found to be 68%, with the latex agglutination results exactly matching the hospital laboratory results (kappa = 1.0). A sensitive and specific method now exists that allows anesthesiologists to assess cocaine use rapidly, so that they can use this information when planning a patient's anesthetic.