Jacob M, Bruegger D, Rehm M, Welsch U, Conzen P, Becker BF: Contrasting effects of colloid and crystalloid resuscitation fluids on cardiac vascular permeability
Clinic of Anesthesiology, Ludwig-Maximilians University Munich, Germany. Anesthesiology
(Impact Factor: 5.88).
06/2006; 104(6):1223-31. DOI: 10.1097/00000542-200606000-00018
Fluid extravasation may lead to myocardial edema and consequent reduction in ventricular function. Albumin is presumed to interact with the endothelial glycocalyx. The authors' objective was to compare the impact of different resuscitation fluids (human albumin, hydroxyethyl starch, saline) on vascular integrity.
In an isolated perfused heart model (guinea pig), Krebs-Henseleit buffer was augmented with colloids (one third volume 5% albumin or 6% hydroxyethyl starch 130/0.4) or crystalloid (0.9% saline). Perfusion pressure and vascular fluid filtration (epicardial transudate formation) were assessed at different flow rates. After global, stopped-flow ischemia (37 degrees C, 20 min), hearts were reperfused with the same resuscitation fluid additives. In a second series, the authors applied the respective perfusates after enzymatic digestion of the endothelial glycocalyx (heparinase, 10 U over 15 min).
Both 5% albumin and 6% hydroxyethyl starch decreased fluid extravasation versus saline (68.4 +/- 5.9, 134.8 +/- 20.5, and 436.8 +/- 14.7 microl/min, respectively, at 60 cm H(2)O perfusion pressure; P < 0.05), the corresponding colloid osmotic pressures being 2.95, 5.45, and 0.00 mmHg. Digestion of the endothelial glycocalyx decreased coronary integrity in both colloid groups. After ischemia, a transient increase in vascular leak occurred with Krebs-Henseleit buffer containing hydroxyethyl starch and saline, but not with albumin. The authors observed no difference between intravascular and bulk interstitial colloid concentration in the steady state. Notwithstanding, electron microscopy revealed an intact endothelial glycocalyx and no interstitial edema in the albumin group.
Ex vivo, albumin more effectively prevented fluid extravasation in the heart than crystalloid or artificial colloid. This effect was partly independent of colloid osmotic pressure and may be attributable to an interaction of albumin with the endothelial glycocalyx.
Available from: Lukas Kubala
- "Albumin supplementation significantly attenuated pronounced shedding of the glycocalyx as well as interstitial edema and the increased adhesion of leukocytes observed after a cold ischemia. Interestingly, experimental studies suggest that concentrations of albumin significantly lower than the physiological value may be sufficient to protect vascular integrity . "
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ABSTRACT: The glycocalyx of the endothelium is an intravascular compartment that creates a barrier between circulating blood and the vessel wall. The glycocalyx is suggested to play an important role in numerous physiological processes including the regulation of vascular permeability, the prevention of the margination of blood cells to the vessel wall, and the transmission of shear stress. Various theoretical models and experimental approaches provide data about changes to the structure and functions of the glycocalyx under various types of inflammatory conditions. These alterations are suggested to promote inflammatory processes in vessels and contribute to the pathogenesis of number of diseases. In this review we summarize current knowledge about the modulation of the glycocalyx under inflammatory conditions and the consequences for the course of inflammation in vessels. The structure and functions of endothelial glycocalyx are briefly discussed in the context of methodological approaches regarding the determination of endothelial glycocalyx and the uncertainty and challenges involved in glycocalyx structure determination. In addition, the modulation of glycocalyx structure under inflammatory conditions and the possible consequences for pathogenesis of selected diseases and medical conditions (in particular, diabetes, atherosclerosis, ischemia/reperfusion, and sepsis) are summarized. Finally, therapeutic strategies to ameliorate glycocalyx dysfunction suggested by various authors are discussed.
Available from: Ørjan G Martinsen
- "For these reasons, it is not surprising that prior attempts have been made to measure electrical potentials on and around acupuncture points. A total of four studies within the English literature reported that the electrical potential at acupuncture points were, on average, 5 to 100 mV more positive than adjacent skin areas [8, 16, 17, 35]. The non-English literature also agreed with this relative direction in potential [17, 36]. "
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ABSTRACT: Objective. Acupuncture points are reportedly distinguishable by their electrical properties. However, confounders arising from skin-to-electrode contact used in traditional electrodermal methods have contributed to controversies over this claim. The Scanning Kelvin Probe is a state-of-the-art device that measures electrical potential without actually touching the skin and is thus capable of overcoming these confounding effects. In this study, we evaluated the electrical potential profiles of acupoints LI-4 and PC-6 and their adjacent controls. We hypothesize that acupuncture point sites are associated with increased variability in potential compared to adjacent control sites. Methods. Twelve healthy individuals were recruited for this study. Acupuncture points LI-4 and PC-6 and their adjacent controls were assessed. A 2 mm probe tip was placed over the predetermined skin site and adjusted to a tip-to-sample distance of 1.0 mm under tip oscillation settings of 62.4 Hz frequency. A 6 × 6 surface potential scan spanning a 1.0 cm × 1.0 cm area was obtained. Results. At both the PC-6 and LI-4 sites, no significant differences in mean potential were observed compared to their respective controls (Wilcoxon rank-sum test, P = 0.73 and 0.79, resp.). However, the LI-4 site was associated with significant increase in variability compared to its control as denoted by standard deviation and range (P = 0.002 and 0.0005, resp.). At the PC-6 site, no statistical differences in variability were observed. Conclusion. Acupuncture points may be associated with increased variability in electrical potential.
Available from: Ashraf S. Hasanin
- "Lopes et al. , in their work revealed that there is reduced morbidity and hospital stay by GDT and this was associated with a reduced interleukin-6 response. Other studies on perioperative changes of the vascular barrier suggest that the endothelial glycocalyx plays a key role  . "
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ABSTRACT: PurposeSeveral studies have shown that hemodynamic and fluid optimization may result in improved outcome. The aim of this study was to compare between two methods of goal directed fluid optimization using protocols guided by corrected flow time (FTc) of the transesophageal doppler versus Pleth variability index (PVI group) in cirrhotic patients undergoing major abdominal surgeries.Methods
Sixty cirrhotic patients Child A to B scheduled for major abdominal surgery were randomized into two groups. In both groups 500 mL of Ringer’s acetate was infused during induction followed by a 2 mL/kg/h continuous infusion. In FTc group (n = 30) patients with (FTc) less than 350 ms were treated with bolus of fluid challenge according to a preset protocol. In PVI group (n = 30), PVI higher than 13% patients were given 250 mL of fluid bolus.ResultsThere was no significant differences in the volume of crystalloids or colloids transfused to both groups with a mean value of 2670 ± 1680 mL and 670 ± 330 mL in the FTc guided fluid group while mean values were 2730 ± 1760 mL and 690 ± 290 mL in the PVI fluid guided group respectively (P > 0.05). Also, there was no significant differences between groups regarding the intra or postoperative hemodynamic parameters. There was no significant difference regarding the overall morbidity or the hospital stay between the two groups (P > 0.05).Conclusions
In conclusion, in cirrhotic patients Child A to B, FTc and PVI were considered to be adequate methods for perioperative fluid optimization, However, combination of every clinical finding, recent and conventional monitoring techniques to all haemodynamic data should be applied whenever possible.
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