Biomedical subjects

L Sheiner

Publications and source records attributed to L Sheiner.

4 recordsLinked to original sources

PubMed1991

VentPlan: a ventilator-management advisor.

VentPlan assists physicians, nurses, and respiratory therapists in the management of artificial respiration for critically ill patients in the intensive-care unit (ICU). VentPlan interprets clinical observations, monitored data, and arterial-blood-gas analyses to make recommendations for setting the ventilator. The VentPlan interface allows users to examine the physiologic model, to inspect details of the data on which the model is based, and to exercise the model to try out different ventilator settings before they implement a new setting. We also report here a preliminary evaluation of VentPlan's ability to predict the arterial oxygen and carbon-dioxide tensions following adjustments to the ventilator. We conclude that VentPlan's physiologic models are acceptably accurate for predicting the effects of small adjustments of the ventilator.

Critical Care↗

PubMed1988

Nicotine absorption and cardiovascular effects with smokeless tobacco use: comparison with cigarettes and nicotine gum.

Because of recent resurgence in its consumption, the effects and health consequences of smokeless tobacco are of considerable public health interest. We studied the extent and time course of absorption of nicotine and cardiovascular effects of smokeless tobacco (oral snuff and chewing tobacco) and compared it with smoking cigarettes and chewing nicotine gum in 10 healthy volunteers. Maximum levels of nicotine were similar but, because of prolonged absorption, overall nicotine exposure was twice as large after single exposures to smokeless tobacco compared with cigarette smoking. All tobacco use increased heart rate and blood pressure, with a tendency toward a greater overall cardiovascular effect despite evidence of development of some tolerance to effects of nicotine with use of smokeless tobacco. Relatively low levels of nicotine and lesser cardiovascular responses were observed with use of nicotine gum. Adverse health consequences of smoking that are nicotine related would be expected to present a similar hazard with the use of smokeless tobacco.

Adult↗

PubMed1985

Computer-assisted drug assay interpretation based on Bayesian estimation of individual pharmacokinetics: application to lidocaine.

A microcomputer program for individualized drug level prediction based on Bayesian forecasting is presented. It is written so that the clinician can integrate patient demographics and drug levels to design a new dosage regimen tailored to an individual patient. The program's great flexibility and robustness make it appropriate for realistic clinical settings. A validation with a data set of lidocaine concentrations measured in 18 patients revealed that the program can predict serum lidocaine levels accurately enough to enhance individual patient dosage adjustment within a few hours after a dosage regimen is started.

Bayes Theorem↗

PubMedDate not supplied

Improving drug dosing in hospitalized patients: automated modeling of pharmacokinetics for individualization of drug dosage regimens.

Many clinical useful drugs have a narrow range of blood concentrations which are both safe and efficacious. Inter-individual and intra-individual variations in drug disposition are important factors causing blood concentrations of drug to fall outside of the therapeutic range. Modeling of the pharmacokinetics of the individual offers an effective approach to the problem of variation in drug disposition. Previous approaches for the modeling of individual pharmacokinetics have required either extensive computations or access to computer software and hardware in the clinical environment, and special expertise to interpret the results. This paper describes a prototype computer program, PK Monitor, which can, when connected with an appropriate interface, automatically monitor drug dosing and recommend changes that may be required to obtain blood concentrations in the therapeutic range. The software can also detect the occurrence of change in drug disposition which will lead to concentrations outside of the therapeutic range, identify potentially erroneous blood concentration measurements, and assess the need for further blood concentration measurements. This program will be an integral part of the MENTOR therapeutic monitoring system of programs. PK Monitor awaits a complete evaluation with the rest of the MENTOR system, but preliminary simulations suggest reasonable sensitivity and specificity in monitoring for unexpected data and change.

Drug Administration Schedule↗