Computer control versus manual control of systemic hypertension during cardiac surgery

Hoeksel, S.A.A.P.; Blom, J. A.; Jansen, Jos R. C.; Schreuder, Johannes Jacobus

doi:10.1034/j.1399-6576.2001.045005553.x

Cited by 13 publications

(2 citation statements)

References 17 publications

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“…The algorithms used in these systems are based on integration of pharmacokinetic and pharmacodynamic models of the anesthetic agent to continuously predict and customize target organ concentration and expected effects (level of anesthesia, mean arterial pressure, etc.). Similar approaches have been used for other anesthetics (see [63][64][65][66] for examples), as well as for vasoactive and chronotropic drugs such as nitroglycerin and nitroprusside [67][68]. The method outlined herein may thus be readily applied to systems such as those described above to improve pharmacokinetic parameter prediction.…”

Section: Discussionmentioning

confidence: 94%

Improved transformation of morphometric measurements for a priori parameter estimation in a physiologically-based pharmacokinetic model of ethanol

Plawecki

DeCarlo

Ramchandani

et al. 2007

Biomedical Signal Processing and Control

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Prescription of the brain's time course of exposure to experimentally administered ethanol can be achieved with intravenous infusion profiles computed from a physiologically-based pharmacokinetic (PBPK) model of alcohol distribution and elimination. Previous parameter estimation employed transformations of an individual's age, height, weight and gender inferred from the literature, with modeling errors overcome with real-time, intermittent feedback. Current research applications, such as ethanol exposures administered during fMRI scanning, require open-loop infusions, thus improved transformation of morphometric measurements.Records of human breath alcohol concentration (BrAC) clamp experiments were analyzed. Optimal, unique PBPK parameters of a model of the distribution and elimination of ethanol were determined for each record and found to be in concordance with parameter values published by other investigators. A linear transformation between the readily measurable physical characteristics or morphometrics, including gender, age, height, weight, and TBW estimates, and the model parameters were then determined in a least squares sense according to the formula theta=F(x)=F(m)x where x=(age height weight TBW)(T)inR(4) and theta =(R(C) V(P) V(B) m(max)k(AT))(T)inR(5).The transformation was then evaluated with several parameter prediction performance measures. A substantial improvement in all error statistics, in relation to an earlier affine transformation that used only body weight as the relevant morphometric was obtained. Deviation from the measured response was reduced from 27 to 20%. Error in parameter estimation was reduced from 109 to 38%. Percent alcohol provided in error was reduced from 46 to 28%. Error in infusion profile estimation was reduced from 55 to 33%.The algorithm described, which optimizes individual pharmacokinetic parameter values and then subsequent extension to a priori prediction, while not unique, can be readily be adapted to other molecules and pharmacokinetic models. This includes those used for distinct purposes, such as automated control of anesthetic agents.

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Section: Discussionmentioning

confidence: 94%

Improved transformation of morphometric measurements for a priori parameter estimation in a physiologically-based pharmacokinetic model of ethanol

Plawecki

DeCarlo

Ramchandani

et al. 2007

Biomedical Signal Processing and Control

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“…Computer-based point of care guidance systems have been used in a number of critical care settings [21][22][23][24] . They can facilitate guidance incorporating complex patient state assessment and offer the possibility of closed loop control 10,25,26 . Thus far, the uptake has been low despite some evidence of clinical effectiveness 27,28 .…”

Section: Discussionmentioning

confidence: 99%

Computer Based Haemodynamic Guidance System is Effective and Safe in Management of Postoperative Cardiac Surgery Patients

Mudaliar

Gopalakrishnan

et al. 2011

Anaesth Intensive Care

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Continuous control of the circulation is an everpresent requirement in the seriously ill and numerous approaches have been advocated 1-6. Rule-based approaches that explicitly direct therapy of blood pressure and cardiac output (CO) do not address the complex nature of the circulation. A monitoring system which could adapt to different physiological states and continuously guide circulatory therapies to achieve predefined pressures and flows might offer significant advantage in the efficiency and consistency of care, to the potential benefit of patients and clinicians. Numerically based, open-or closed-loop, targeted circulatory guidance may offer advantages but has not yet become a mainstream procedure. The circular nature of the system and the complex ways in which the blood volume, heart activity, resistances and compliances interact to determine pressures, blood and oxygen flows defy easy analysis 7. The essence of the problem is to resolve the ordinarily measured circulatory variables (CO, mean arterial pressure [MAP] and right atrial pressure [RAP]) into their volume, resistive and cardiac dependencies as it is the latter that are the objects of therapeutic control. This is the essential first step in forming a consistent mathematical relationship between measured data and therapy. Our approach to this problem is to use the mean systemic filling pressure (P ms) and not any preload measure, to define the volume state. Additionally, together with RAP, P ms permits novel definition of global heart performance E h 8-10 .

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Drug Infusion Systems

Özçelik

2006

Encyclopedia of Medical Devices and Instrumentation

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Drug infusion systems are being extensively used in hospitals as well as in home therapies. Device‐based drug delivery systems are used in a wide range of pharmacological therapy and can be classified as injection–infusion systems, transdermal patch‐based systems, and inhalation systems. These devices range in complexity from simple manual gravity drippers to fully automated sophisticated complete infusion systems. Contributions of engineering, basic sciences, and technological advancements have significantly improved drug administration in patients and have significantly eliminated medication errors due to users. This article focuses on the injection–infusion systems, reviews basic types and operational principles of these systems, and presents recent developments and advancements.

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Computer control versus manual control of systemic hypertension during cardiac surgery

Abstract: We conclude that, compared with manual control, computer control of systemic hypertension significantly improved hemodynamic stability during cardiac surgery.

Cited by 13 publications

References 17 publications

Improved transformation of morphometric measurements for a priori parameter estimation in a physiologically-based pharmacokinetic model of ethanol

Improved transformation of morphometric measurements for a priori parameter estimation in a physiologically-based pharmacokinetic model of ethanol

Computer Based Haemodynamic Guidance System is Effective and Safe in Management of Postoperative Cardiac Surgery Patients

Drug Infusion Systems

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