Energy Equivalent Expansion

1990 ◽  
Author(s):  
Naresh Patel ◽  
Ajmal Yousuff
Keyword(s):  
Author(s):  
V.I. Cherniy ◽  
A.I. Denysenko

The purpose of the study is to develop a method of perioperative energy monitoring and to implement it in clinical practice. Material and methods. The study involved 125 patients who underwent various surgical interventions under general anesthesia using sevoflurane (inhalation anesthetics) and fentanyl (narcotic analgesics) in low-flow artificial lung ventilation. Methods of perioperative monitoring (International Standards for a Safe Practice of Anesthesia 2010, WFSA) were supplemented using indirect calorimetry. Results. Analyzing the literature data, a close correlation was found between the energy equivalent of oxygen (EEE2) and the respiratory factor (RQ). The authors obtained the corresponding one-factor linear regression formula, which had the form: EEE2 = 1.157 × RQ + 4,037. Using the basic principles of gas exchange in the lungs of Bohr-Engoff, a method of perioperative energy monitoring was developed, based on indirect calorimetry, taking into account the real values ​​of the energy equivalent of patients' oxygen. The universal formula for determining the level of metabolism of the patient (MR, cal / min) in the form of: MR = [0,863 × VE × (PECO2 / PaCO2) × (FiO2 - FeO2)] (1,157 × RQ + 4,037) where, VE - total ventilation of the lungs per minute (ml / min), PECO2, PaCO2 - partial pressure, respectively, in a mixture of gases, which is exhaled and in the arterial blood (mm Hg). FiO2 and FEO2 are the oxygen fraction in the gas mixture that is inhaled and exhaled in units (% / 100). The method is implemented as a computer program created on the basis of the developed formula. The methods of intensive perioperative therapy taking into account the level of metabolism are presented. Conclusion. The method of perioperative energy monitoring substantially complements the "International Standards for Safe Anesthesiology Practice", WFSA (2010) enhances the perioperative safety of patients by detecting metabolic disorders and conducting appropriate pathogenetic correction.


This chapter applies the ? model to the United States of America. By assuming that the US is a ‘world-system,' we can measure the economic efficiency of each state (and the District of Columbia). The model predicts an output floor based on the inputs of land and people as per-unit energy-equivalents. This expected output is then compared to the actual Gross State Product (GSP) as a per-unit energy-equivalent. States that are economically efficient register a positive residual, and hence a positive ? score. However, given potential measurement inaccuracies, states with low negative scores are also added to this efficient tier.


Perfusion ◽  
2018 ◽  
Vol 34 (4) ◽  
pp. 297-302
Author(s):  
Anke Dürr ◽  
Andreas Kunert ◽  
Günter Albrecht ◽  
Andreas Liebold ◽  
Markus Hoenicka

Introduction: Pulsatile extracorporeal circulation may improve organ perfusion during cardiac surgery. Some minimally invasive extracorporeal circulation (MiECC) systems allow pulsatile perfusion. The present study investigated the influence of arterial tubing compliance on hemodynamic energy transfer into the patient. Methods: Aortic models with adult human geometry were perfused in a mock circulation. A MiECC system was connected using either high-compliance silicone tubing or standard kit tubing. Energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE) were computed from flow and pressure data. Aortic models with physiological and sub-physiological compliance were tested to assess the influence of the pseudo-patient. Results: Non-pulsatile flow did not generate SHE. SHE during pulsatile flow in the compliant aortic model was significantly higher with kit tubing compared to silicone tubing. Maximum SHE was achieved at 1.6 L/min with kit tubing (7.7% of mean arterial pressure) and with silicone tubing (4.9%). Using the low-compliance aortic model, SHE with kit tubing reached a higher maximum of 14.2% at 1.8 L/min compared to silicone tubing (11.8% at 1.5 L/min). Conclusions: Flexible arterial tubing did not preserve more hemodynamic energy from a pulsatile pump compared to standard kit tubing in a model of adult extracorporeal circulation. The pseudo-patient’s compliance significantly affected the properties of the mock circulation.


2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Varun A. Bhatia ◽  
W. Brent Edwards ◽  
Joshua E. Johnson ◽  
Karen L. Troy

Bone adaptation is understood to be driven by mechanical strains acting on the bone as a result of some mechanical stimuli. Although the strain/adaptation relation has been extensively researched using in vivo animal loading models, it has not been studied in humans, likely due to difficulties in quantifying bone strains and adaptation in living humans. Our purpose was to examine the relationship between bone strain and changes in bone mineral parameters at the local level. Serial computed tomography (CT) scans were used to calculate 14 week changes in bone mineral parameters at the distal radius for 23 women participating in a cyclic in vivo loading protocol (leaning onto the palm of the hand), and 12 women acting as controls. Strains were calculated at the distal radius during the task using validated finite element (FE) modeling techniques. Twelve subregions of interest were selected and analyzed to test the strain/adaptation relation at the local level. A positive relationship between mean energy equivalent strain and percent change in bone mineral density (BMD) (slope = 0.96%/1000 με, p < 0.05) was observed within experimental, but not control subjects. When subregion strains were grouped by quartile, significant slopes for quartile versus bone mineral content (BMC) (0.24%/quartile) and BMD (0.28%/quartile) were observed. Increases in BMC and BMD were greatest in the highest-strain quartile (energy equivalent strain > 539 με). The data demonstrate preliminary prospective evidence of a local strain/adaptation relationship within human bone. These methods are a first step toward facilitating the development of personalized exercise prescriptions for maintaining and improving bone health.


Sign in / Sign up

Export Citation Format

Share Document