Biomedical subjects
John A Smith
Publications and source records attributed to John A Smith.
Drug recognition expert evaluations made using limited data.
The Drug Evaluation Classification (DEC) Program is used by Drug Recognition Expert (DRE) officers to determine whether a suspect is under the influence of a drug or drugs at the time of arrest, and, if so, what category of drug(s). The goal of this project was to investigate the relative importance of face-to-face interactions with the suspect, physical evidence (drugs or paraphernalia found), and confessions/statements made by the suspect (or others) in making these determinations. Seventy records of DRE evaluations were selected from a database containing information from all evaluations conducted in Oregon between 1996 and 1998. Each of the 70 records represented a suspect who had either taken a drug from one of four categories (CNS depressant, CNS stimulant, narcotic analgesic, or cannabis) or who had not taken a drug. To be included, the original DRE evaluation and the subsequent toxicology analysis had to agree that the suspect was under the influence of a drug from one of the four categories or not under the influence of a drug. Records from the 70 cases were submitted in written form to 18 Oregon DREs with statements made by suspects or arresting officers, confessions, toxicology results, and descriptions of drugs or paraphernalia found on the suspect omitted. Based only on the written reports of direct observations, and with physiological and psychophysical test results, the DREs attempted to determine whether each of the 70 suspects was under the influence of a drug or drugs, and, if so, what category of drug(s). If the officers determined that a suspect was under the influence of a drug, their accuracy in specifying the drug category was 81% for cannabis, 94% for narcotic analgesics, 78% for CNS stimulants, and 69% for CNS depressants. Overall accuracy in recognizing drug intoxication was 95%. These percentages indicate that although face-to-face interactions, physical evidence, and confessions/statements can be useful adjuncts to DRE decision-making, the majority of drug category decisions can be made solely on the basis of recorded suspect observations and DRE evaluation results.
Cardiopulmonary effects of xylazine and acepromazine in pregnant cows in late gestation.
OBJECTIVE: To determine effects of sedation achieved by xylazine (XYL) or acepromazine (ACE) on cardiopulmonary function and uterine blood flow in cows in late gestation. ANIMALS: 8 cows between 219 and 241 days of gestation. PROCEDURE: Doses of ACE (0.02 mg/kg) or XYL (0.04 mg/kg) were administered IV. Measurements were obtained to determine cardiopulmonary effects and oxygen delivery to the uterus. RESULTS: Heart rate was not significantly affected by administration of ACE, but it decreased markedly after administration of XYL. Uterine artery flow was decreased at all times by XYL and was always less than for ACE. Xylazine increased uterine vascular resistance through 30 minutes and caused reduced PaO2 and increased PaCO2 at all time periods. Acepromazine caused a 5% decrease in PaO2 only at 5 minutes. Xylazine reduced oxygen delivery by 59% at 5 minutes and 32% at 45 minutes. In contrast, ACE caused a nonsignificant reduction of oxygen delivery by 16% at 15 minutes and a return to baseline values by 45 minutes CONCLUSIONS AND CLINICAL RELEVANCE: Xylazine markedly reduces flow and availability of oxygenated blood to the uterus, which may critically impair delivery of oxygen to the fetus at a stressful and important time of development or delivery. Acepromazine was associated with slight reductions of much shorter duration. When XYL is used to sedate pregnant cows, it could impose physiologic distress on the fetus and potentially increase fetal morbidity and mortality. When sedation of the dam is desirable, ACE could be an alternative to XYL.