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Biomedical subjects

C A Sutheimer

Publications and source records attributed to C A Sutheimer.

10 recordsLinked to original sources
PubMed1985

Effects of low-dose morphine and fentanyl infusions on urinary and plasma catecholamine concentrations during scoliosis surgery.

Plasma and urinary catecholamines were measured in 20 patients during scoliosis surgery to determine whether low dose fentanyl (1.5-2.5 micrograms . kg-1 . min-1) and morphine (150-250 micrograms . kg-1 . min-1) affect the catecholamine stress response to surgery differently. In all patients epinephrine (1.6-11.4 micrograms/kg) was injected locally at the operative site for hemostasis. This was an advantage because exogenous and endogenous epinephrine undergo the same fate and the increase in epinephrine might enhance otherwise subtle effects. The data indicate that both narcotics have similar effects on catecholamine metabolism but that even low doses of fentanyl are more effective than morphine in obtunding the catecholamine response to painful stimuli. Also, postoperative differences in plasma epinephrine indicate that recovery of awareness, and thus the onset of postoperative pain, is more rapid in patients receiving fentanyl.

Adolescent↗
PubMed1976

Relative merits of some methods for amphetamine assay in biological fluids.

We describe principles and details that we use for amphetamine determination in blood and urine by photometric, thin-layer chromatographic, gas-chromatographic, and immunologic (EMIT and radioimmunoassay) procedures. Results, interferences, stabilities, and economic considerations are intercompared and recommendations are made.

Amphetamine↗
PubMedDate not supplied

Role of the toxicology laboratory in the treatment of acute poisoning.

The modern toxicology laboratory can play an important role in the evaluation of poisoning. In order to appreciate the nature and extent of this role, several essential elements necessary to an acute care toxicology service should be considered. When an ongoing and effective dialogue between clinicians and the toxicology laboratory staff is established, and a broadly based analytical approach is applied to the analysis of the appropriate biological fluids, a dynamic and viable toxicology service will result. How these elements work together to facilitate this service will be discussed, based primarily on experience in a large teaching hospital. This experience indicates that if the elements necessary to provide laboratory support in the investigation of an alleged poisoning are in place, the toxicology laboratory plays an important role in ensuring optimum and effective patient care.

Clinical Laboratory Techniques↗
PubMedDate not supplied

Automated rule-based decision systems in forensic toxicology using expert knowledge: basic principles and practical applications.

This paper presents the basic principles and practical benefits of the application of expert systems (ES) and artificial intelligence (AI) to problem solving in forensic toxicology. We acknowledge the complexity and elegance of the theoretical substance and program algorithms of existing work in these disciplines, while simultaneously observing that many presentations of this material cloak the essential facts and concepts in unnecessary jargon and hyperbole. We attempt to remove the cloak without misrepresenting or oversimplifying the underlying structures. We first present a summary of the history, basic functions, technical fundamentals, and typical applications in three major categories of established ES/AI systems. We then assess the status of ES/AI in the forensic toxicology laboratory (FTL) with emphasis on potential applications. We conclude with an analysis of experiences with ESs in our laboratory where we have used an integrated expert system to reduce laboratory errors, detect internal inconsistencies in data, discover new substance abuse subpopulations, and reduce the frequency of sample reprocessing. We have minimized specimen processing time and instrument wear while maximizing technician efficiency and thus performing more tests for the same or reduced costs.

Artificial Intelligence↗
PubMedDate not supplied

Computerized controlled-substance inventory management in a forensic toxicology laboratory: practical application of a state-change model.

Efficient, accurate, secure, comprehensively audited, and legally defensible maintenance of an electronic chain-of-custody applied to a controlled-substance inventory system in a busy forensic toxicology lab (FTL) has been achieved with custom-written software which is based on a general state-change model. Prior to the use of this program we were unfortunately accustomed to being surprised by incomplete drug use documentation leading to pseudo-shortages, expired or uncertified lots, the lack of an adequate chain of custody, and the risk of legal challenges. This resulted in confusion, delays, and emergency orders, with the inevitable waste of time and money. The control strategy implemented in the INVEN subsystem of our main system, TOXLAB, is based on four principles. First, access to the drug inventory is strictly limited. Second, controlled drugs are dispersed to technical staff only when a computer-authorized request form is presented. Third, every request for addition/subtraction must be pre-authorized by the supervisor. Fourth, the program enforces a strict progression of requests and actions from one state to another and produces request, authorization and certification, and/or approval logs ready for signature at every step. This approach has given us a comprehensive, chronological record of all events involving drug inventory transactions and promises to improve resource utilization. Our system appears to fulfill the basic requirements for the legal adequacy of computer-resident data.

Forensic Medicine↗
PubMedDate not supplied

Evaluation of the Syva ETS-PLUS Ethyl Alcohol Assay with application to the analysis of antemortem whole blood, routine postmortem specimens, and synovial fluid.

A critical evaluation of the ETS-PLUS Ethyl Alcohol Assay indicates that it is simple to perform, sensitive enough to reliably detect ethanol above a concentration of 0.010 g/dL, and dynamic enough to reliably quantitate ethanol concentrations between 0.010 and 0.400 g/dL, correlating well with headspace gas chromatography. The technique is suitable for the analysis of relatively fresh (less than 1 month old) serum, plasma, urine, bile, vitreous humor, and gastric samples. With the aid of dilution, it is adaptable to the analysis of whole blood, relatively old specimens (more than 3 months old), viscous and highly pigmented plasma, bile, and the occasional extremely viscous vitreous humor specimens. Our evaluation further indicates that samples can remain in the system's covered sample wheel for up to 2 h without significant (less than 10%) diminution in ethanol concentration. This technique was further utilized to evaluate the suitability of synovial fluid as an alternative for vitreous humor.

Ethanol↗
PubMedDate not supplied

EMIT-st screening for drugs of abuse: methaqualone.

The Emit-st (single test) drug detection system was determined, for methaqualone and several of its metabolites, to be reliable and simple to perform. Its sensitivity was 0.3 micrograms/mL for methaqualone and 0.4 micrograms/mL for the only methaqualolne metabolite (4-hydroxymethaqualone) known to be excreted unconjugated. This assay also detects mecloqualone, a Schedule I drug marketed in Europe and South Africa.

Humans↗
PubMedDate not supplied

Detection and confirmation of urinary cannabinoids.

Both a thin layer chromatographic procedure (TOXI-LAB) and two homogeneous immunoassays with differing sensitivity limits (EMIT-st, and EMIT d.a.u.) were used to test 525 urine specimens for metabolites of tetrahydrocannabinol. Negative results were obtained by all techniques for 283 specimens. The EMIT-st was positive for 184 specimens, the EMIT-d.a.u. for 47 additional specimens. The TOXI-LAB results were positive for all these 231 specimens. An additional 11 specimens were positive by EMIT-d.a.u. and negative by TOXI-LAB. Gas chromatography/mass spectrometry analyses of five of these 11 indicated that their average 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid concentration was 7.4 +/- 2.2 ng/mL, well below the lower detection limit of the TOXI-LAB procedure. Using both EMIT-d.a.u. and TOXI-LAB assures a reliable urinary cannabinoid analysis above a concentration of 25 ng/mL.

Cannabinoids↗
PubMedDate not supplied

The role of the toxicology laboratory in emergency medicine.II: Study of an integrated approach.

The utility of the toxicology laboratory in emergency medicine is directly related to both establishing communication between the toxicology laboratory and the clinical staff, and to providing reliable toxicology data while the diagnostic process is still in progress. When 604 patients, on whom a "complete toxicology screen" was requested, were evaluated using qualitative probes involving chemical spot tests, immunoassay, TLC and/or selected GC/HPLC methods, the resulting data were demonstrated to be of value. The ability of the clinician to accurately predict which, if any, of a large number of intoxicants were present in a given patient, was found to be minimal and as a result these combined tests were found to be essential in facilitating a proper diagnosis. Additionally, it was found that using only chemical spot tests, immunoassay and TLC in a combined qualitative approach detected 94-98% of all the substances eventually found within the population when it was further studied using more sophisticated instrumental methods. The integrated approach involving the initial establishment of a dialogue between the clinician and the toxicologist, use of simple qualitative analytical probes, confirmation of positive findings and prompt reporting of toxicology data is a viable way in which meaningful toxicology support can be provided while the diagnostic process is still underway.

Adolescent↗