Effect of Drug Infusion on the Splanchnic Circulation. I. Angiotensin Infusion in Normal and Cirrhotic Subjects

1963 ◽  
Vol 112 (2) ◽  
pp. 324-326 ◽  
Author(s):  
L. Chiandussi ◽  
A. Vaccarino ◽  
F. Greco ◽  
F. Muratori ◽  
L. Cesano ◽  
...  
Keyword(s):  
Splanchnic Circulation ◽  
Drug Infusion

Effect of Drug Infusion on Splanchnic Circulation. II. Serotonin Infusion In Normal and Cirrhotic Subjects

1963 ◽  
Vol 112 (2) ◽  
pp. 326-328 ◽  
Author(s):  
L. Chiandussi ◽  
F. Greco ◽  
D. Indovina ◽  
L. Cesano ◽  
A. Vaccarino ◽  
...  
Keyword(s):  
Splanchnic Circulation ◽  
Drug Infusion

scholarly journals A “Smart” Biosensor-Enabled Intravascular Catheter and Platform for Dynamic Delivery of Propofol to “Close the Loop” for Total Intravenous Anesthesia

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 370-377
Author(s):  
Edward Chaum ◽  
Ernő Lindner
Keyword(s):  
Real Time ◽  
Drug Distribution ◽  
Population Based ◽  
Pharmacokinetic Data ◽  
Drug Infusion ◽  
Blood Concentrations ◽  
The Usa ◽  
The Difference ◽  
Automated Delivery

ABSTRACT Background Target-controlled infusion anesthesia is used worldwide to provide user-defined, stable, blood concentrations of propofol for sedation and anesthesia. The drug infusion is controlled by a microprocessor that uses population-based pharmacokinetic data and patient biometrics to estimate the required infusion rate to replace losses from the blood compartment due to drug distribution and metabolism. The objective of the research was to develop and validate a method to detect and quantify propofol levels in the blood, to improve the safety of propofol use, and to demonstrate a pathway for regulatory approval for its use in the USA. Methods We conceptualized and prototyped a novel “smart” biosensor-enabled intravenous catheter capable of quantifying propofol at physiologic levels in the blood, in real time. The clinical embodiment of the platform is comprised of a “smart” biosensor-enabled catheter prototype, a signal generation/detection readout display, and a driving electronics software. The biosensor was validated in vitro using a variety of electrochemical methods in both static and flow systems with biofluids, including blood. Results We present data demonstrating the experimental detection and quantification of propofol at sub-micromolar concentrations using this biosensor and method. Detection of the drug is rapid and stable with negligible biofouling due to the sensor coating. It shows a linear correlation with mass spectroscopy methods. An intuitive graphical user interface was developed to: (1) detect and quantify the propofol sensor signal, (2) determine the difference between targeted and actual propofol concentration, (3) communicate the variance in real time, and (4) use the output of the controller to drive drug delivery from an in-line syringe pump. The automated delivery and maintenance of propofol levels was demonstrated in a modeled benchtop “patient” applying the known pharmacokinetics of the drug using published algorithms. Conclusions We present a proof-of-concept and in vitro validation of accurate electrochemical quantification of propofol directly from the blood and the design and prototyping of a “smart,” indwelling, biosensor-enabled catheter and demonstrate feedback hardware and software architecture permitting accurate measurement of propofol in blood in real time. The controller platform is shown to permit autonomous, “closed-loop” delivery of the drug and maintenance of user-defined propofol levels in a dynamic flow model.

Comparison of the Effect-site keOs of Propofol for Blood Pressure and EEG Bispectral Index in Elderly and Younger Patients

1999 ◽  
Vol 90 (6) ◽  
pp. 1517-1527. ◽  
Author(s):  
Tomiei Kazama ◽  
Kazuyuki Ikeda ◽  
Koji Morita ◽  
Mutsuhito Kikura ◽  
Matsuyuki Doi ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Plasma Concentration ◽  
Bispectral Index ◽  
Time Course ◽  
Drug Infusion ◽  
Time Data ◽  
Aged Patients ◽  
Younger Patients ◽  
Spectral Edge Frequency ◽  
Effect Site

Background Drug effect lags behind the blood concentration. The goal of this investigation was to determine the time course of plasma concentration and the effects of propofol demonstrated by electroencephalogram or blood pressure changes and to compare them between elderly and young or middle-aged patients. Methods A target-controlled infusion was used to rapidly attain and maintain four sequentially increasing, randomly selected plasma propofol concentrations from 1 to 12 microg/ml in 41 patients aged 20-85 yr. The target concentration was maintained for about 30 min. Bispectral index (BIS), spectral edge frequency, and systolic blood pressure (SBP) were used as measures of propofol effect. Because the time courses of these measures following the started drug infusion showed an exponential pattern, the first-order rate constant for equilibration of the effect site with the plasma concentration (k(eO)) was estimated by fitting a monoexponential model to the effect versus time data resulting from the pseudo-steady-state propofol plasma concentration profile. Results The half-times for the plasma-effect-site equilibration for BIS were 2.31, 2.30, 2.29, and 2.37 min in patients aged 20-39, 40-59, 60-69, and 70-85 yr, respectively (n = 10 or 11 each). The half-times for SBP were 5.68, 5.92, 8.87, and 10.22 min in the respective age groups. All were significantly longer than for BIS (P < 0.05). The propofol concentration at half of the maximal decrease of SBP was significantly greater (P < 0.05) in the elderly than in the younger patients. Conclusions The effect of propofol on BIS occurs more rapidly than its effect on SBP. Age has no effect on the rate of BIS reduction with increasing propofol concentration, whereas with increasing age, SBP decreases to a greater degree but more slowly.

Drug infusion through a branch of the aortocoronary vein graft for refractory coronary spasm

1994 ◽  
Vol 58 (3) ◽  
pp. 869-871 ◽  
Author(s):  
Hisanori Mayumi ◽  
Yoshito Kawachi ◽  
Hiroyuki Kohno ◽  
Yuji Akaiwa ◽  
Manabu Hisahara ◽  
...  
Keyword(s):  
Vein Graft ◽  
Coronary Spasm ◽  
Drug Infusion

Computer Simulation of Adaptive Drug Infusion

1987 ◽  
Vol BME-34 (8) ◽  
pp. 633-635 ◽  
Author(s):  
Charles Yurkonis ◽  
Robert Arzbaecher
Keyword(s):  
Computer Simulation ◽  
Drug Infusion

Vasomotion and Contraction in the Perfused Mesenteric–Portal Vein: Effect of Drugs and Altered Perfusion Pressure

1971 ◽  
Vol 49 (6) ◽  
pp. 615-618 ◽  
Author(s):  
H. James Rhodes ◽  
M. C. Sutter
Keyword(s):  
Portal Vein ◽  
Perfusion Pressure ◽  
Splanchnic Circulation ◽  
Intraluminal Pressure ◽  
Longitudinal Tension ◽  
Portal Veins ◽  
Spontaneous Contractions

Isolated rabbit anterior mesenteric–portal veins (A.M.V.) which possess vasomotion were perfused with Kreb's solution in an apparatus designed so that intraluminal pressure and longitudinal tension could be measured simultaneously. The rate of vasomotion increased as perfusion pressure was increased from 0 to approximately 5 or 6 mm Hg. The amplitude of these spontaneous contractions increased to a maximum at a perfusion pressure of approximately 6 mm Hg and then decreased as perfusion pressure was raised further. Noradrenaline (10−7 g/ml) increased the longitudinal tension, but slightly decreased intraluminal pressure. Isopropylnoradrenaline (10−7 g/ml) had little effect on intraluminal pressure but decreased the amplitude of spontaneous contractions. It is suggested that the effect of perfusion pressure on the frequency and amplitude of vasomotion in the A.M.V. is related to autoregulation and that this perfused preparation may be a useful model for study of the rheology and responses to drugs of the splanchnic circulation.

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