[vasopressin Intravenous Infusion Causes Dose Dependent Adverse Cardiovascular Effects In Anesthetized Dogs].

BACKGROUND: Arginine vasopressin (AVP) has been broadly used in the management of vasodilatory shock. However, there are many concerns regarding its clinical use, especially in high doses, as it can be associated with adverse cardiovascular events. OBJECTIVE: To investigate the cardiovascular effects of AVP in continuous IV infusion on hemodynamic parameters in dogs. METHODS: Sixteen healthy mongrel dogs, anesthetized with pentobarbital were intravascularly catheterized, and randomly assigned to: control (saline-placebo; n=8) and AVP (n=8) groups. The study group was infused with AVP for three consecutive 10-minute periods at logarithmically increasing doses (0.01; 0.1 and 1.0 U/kg/min), at them 20-min intervals. Heart rate (HR) and intravascular pressures were continuously recorded. Cardiac output was measured by the thermodilution method. RESULTS: No significant hemodynamic effects were observed during 0.01 U/kg/min of AVP infusion, but at higher doses (0.1 and 1.0 U/kg/min) a progressive increase in mean arterial pressure (MAP) and systemic vascular resistance index (SVRI) were observed, with a significant decrease in HR and the cardiac index (CI). A significant increase in the pulmonary vascular resistance index (PVRI) was also observed with the 1.0 U/kg/min dose, mainly due to the decrease in the CI. CONCLUSION: AVP, when administered at doses between 0.1 and 1.0 U/kg/min, induced significant increases in MAP and SVRI, with negative inotropic and chronotropic effects in healthy animals. Although these doses are ten to thousand times greater than those routinely used for the management of vasodilatory shock, our data confirm that AVP might be used carefully and under strict hemodynamic monitoring in clinical practice, especially if doses higher than 0.01 U/kg/min are needed.942213218, 229-234, 216-22

Designing CNC knit for hybrid membrane and bending active structures structural membranes 2015

Recent advances in computation allow for the integration of design and simulation of highly interrelated systems, such as hybrids of structural membranes and bending active elements. The engaged complexities of forces and logistics can be mediated through the development of materials with project specific properties and detailing. CNC knitting with high tenacity yarn enables this practice and offers an alternative to current woven membranes. The design and fabrication of an 8m high fabric tower through an interdisciplinary team of architects, structural and textile engineers, allowed to investigate means to design, specify, make and test CNC knit as material for hybrid structures in architectural scale. This paper shares the developed process, identifies challenges, potentials and future work

Targeting spectrin redox switches to regulate the mechanoproperties of red blood cells

The mechanical properties of red blood cells (RBCs) are fundamental for their physiological role as gas transporters. RBC flexibility and elasticity allow them to survive the hemodynamic changes in the different regions of the vascular tree, to dynamically contribute to the flow thereby decreasing vascular resistance, and to deform during the passage through narrower vessels. RBC mechanoproperties are conferred mainly by the structural characteristics of their cytoskeleton, which consists predominantly of a spectrin scaffold connected to the membrane via nodes of actin, ankyrin and adducin. Changes in redox state and treatment with thiol-targeting molecules decrease the deformability of RBCs and affect the structure and stability of the spectrin cytoskeleton, indicating that the spectrin cytoskeleton may contain redox switches. In this perspective review, we revise current knowledge about the structural and functional characterization of spectrin cysteine redox switches and discuss the current lines of research aiming to understand the role of redox regulation on RBC mechanical properties. These studies may provide novel functional targets to modulate RBC function, blood viscosity and flow, and tissue perfusion in disease conditions

Vasopressin Intravenous Infusion Causes Dose Dependent Adverse Cardiovascular Effects In Anesthetized Dogs [infusión Intravenosa De Vasopresina Causa Efectos Cardiovasculares Adversos Dependientes De La Dosis En Cãnes Anestesiados]

Background: Arginine vasopressin (AVP) has been broadly used in the management of vasodilatory shock. However, there are many concerns regarding its clinical use, especially in high doses, as it can be associated with adverse cardiovascular events. Objective: To investigate the cardiovascular effects of AVP in continuous IV infusion on hemodynamic parameters in dogs. Methods: Sixteen healthy mongrel dogs, anesthetized with pentobarbital were intravascularly catheterized, and randomly assigned to: control (saline-placebo; n=8) and AVP (n=8) groups. The study group was infused with AVP for three consecutive 10-minute periods at logarithmically increasing doses (0.01; 0.1 and 1.0U/kg/min), at them 20-min intervals. Heart rate (HR) and intravascular pressures were continuously recorded. Cardiac output was measured by the thermodilution method. Results: No significant hemodynamic effects were observed during 0.01U/kg/min of AVP infusion, but at higher doses (0.1 and 1.0U/kg/min) a progressive increase in mean arterial pressure (MAP) and systemic vascular resistance index (SVRI) were observed, with a significant decrease in HR and the cardiac index (CI). A significant increase in the pulmonary vascular resistance index (PVRI) was also observed with the 1.0U/kg/min dose, mainly due to the decrease in the CI. Conclusion: AVP, when administered at doses between 0.1 and 1.0U/kg/min, induced significant increases in MAP and SVRI, with negative inotropic and chronotropic effects in healthy animals. Although these doses are ten to thousand times greater than those routinely used for the management of vasodilatory shock, our data confirm that AVP might be used carefully and under strict hemodynamic monitoring in clinical practice, especially if doses higher than 0.01 U/kg/min are needed.942216221+213-218+229-234Vincent, J.L., Su, F., Physiology and pathophysiology of the vasopressinergic system (2008) Best Pract Res Clin Anaesthesiol, 22, pp. 243-252Cartheuser, C.F., Komarek, J., Effects of vasopressin on the circulation, myocardial dynamics, and left ventricular oxygen consumption in the anesthetized dog (1980) Basic Research in Cardiology, 75 (5), pp. 668-682. , DOI 10.1007/BF01907696Evora, P.R.B., Pearson, P.J., Rodrigues, A.J., Viaro, F., Schaff, H.V., Effect of arginine vasopressin on the canine epicardial coronary artery. Experiments on V1-receptor-mediated production of nitric oxide (2003) Arquivos Brasileiros de Cardiologia, 80 (5), pp. 489-494. , http://www.scielo.br/pdf/abc/v80n5/15756.pdfHollenberg, S.M., Ahrens, T.S., Annane, D., Astiz, M.E., Chalfin, D.B., Dasta, J.F., Practice parameters for hemodynamic support of sepsis in adult patients: 2004 update (2004) Crit Care Med, 32, pp. 1928-1948Holmes, C.L., Patel, B.M., Russell, J.A., Walley, K.R., Physiology of vasopressin relevant to management of septic shock (2001) Chest, 120 (3), pp. 989-1002. , DOI 10.1378/chest.120.3.989Katori, E., Ohta, T., Nakazato, Y., Ito, S., Vasopressin-induced contraction in the rat basilar artery in vitro (2001) European Journal of Pharmacology, 416 (1-2), pp. 113-121. , DOI 10.1016/S0014-2999(01)00781-6, PII S0014299901007816Kusano, E., Tian, S., Umino, T., Tetsuka, T., Ando, Y., Asano, Y., Arginine vasopressin inhibits interleukin-1beta-stimulated nitric oxide and cyclic guanosine monophosphate production via the V1 receptor in cultured rat vascular smooth muscle cells (1997) Journal of Hypertension, 15 (6), pp. 627-632. , DOI 10.1097/00004872-199715060-00009Maybauer, M.O., Maybauer, D.M., Enkhbaatar, P., Physiology of the vasopressin receptors (2008) Best Pract Res Clin Anaesthesiol, 22, pp. 253-263Landry, D.W., Oliver, J.A., The pathogenesis of vasodilatory shock (2001) N Engl J Med, 345, pp. 588-595Lin, I.Y., Ma, H.P., Lin, A.C., Chong, C.F., Lin, C.M., Wang, T.L., Low plasma vasopressin/norepinephrine ratio predicts septic shock (2005) Am J Emerg Med, 23, pp. 718-724Den Ouden, D.T., Meinders, A.E., Vasopressin: Physiology and clinical use in patients with vasodilatory shock: a review (2005) Netherlands Journal of Medicine, 63 (1), pp. 4-13Russell, J.A., Walley, K.R., Singer, J., Gordon, A.C., Hebert, P.C., Cooper, D.J., Holmes, C.L., Ayers, D., Vasopressin versus norepinephrine infusion in patients with septic shock (2008) New England Journal of Medicine, 358 (9), pp. 877-887. , http://content.nejm.org/cgi/reprint/358/9/877.pdf, DOI 10.1056/NEJMoa067373Barrett, L.K., Singer, M., Clapp, L.H., Vasopressin: Mechanisms of action on the vasculature in health and in septic shock (2007) Critical Care Medicine, 35 (1), pp. 33-40. , DOI 10.1097/01.CCM.0000251127.45385.CD, PII 0000324620070100000006Wenzel, V., Krismer, A.C., Arntz, H.R., Sitter, H., Stadlbauer, K.H., Lindner, K.H., A Comparison of Vasopressin and Epinephrine for Out-of-Hospital Cardiopulmonary Resuscitation (2004) New England Journal of Medicine, 350 (2), pp. 105-113. , DOI 10.1056/NEJMoa025431Gueugniaud, P.-Y., David, J.-S., Chanzy, E., Hubert, H., Dubien, P.-Y., Mauriaucourt, P., Braganca, C., Marret, E., Vasopressin and epinephrine vs. epinephrine alone in cardiopulmonary resuscitation (2008) New England Journal of Medicine, 359 (1), pp. 21-30. , http://content.nejm.org/cgi/reprint/359/1/21.pdf, DOI 10.1056/NEJMoa0706873Malay, M.B., Ashton Jr., R.C., Landry, D.W., Townsend, R.N., Low-dose vasopressin in the treatment of vasodilatory septic shock (1999) Journal of Trauma - Injury, Infection and Critical Care, 47 (4), pp. 699-705. , DOI 10.1097/00005373-199910000-00014Maxime, V., Siami, S., Annane, D., Metabolism modulators in sepsis: The abnormal pituitary response (2007) Critical Care Medicine, 35 (9 SUPPL.), pp. S596-S601. , DOI 10.1097/01.CCM.0000279097.67263.52, PII 0000324620070900100027Obritsch, M.D., Bestul, D.J., Jung, R., Fish, D.N., MacLaren, R., The role of vasopressin in vasodilatory septic shock (2004) Pharmacotherapy, 24 (8), pp. 1050-1063. , DOI 10.1592/phco.24.11.1050.36144Patel, B.M., Chittock, D.R., Russell, J.A., Walley, K.R., Beneficial effects of short-term vasopressin infusion during severe septic shock (2002) Anesthesiology, 96 (3), pp. 576-582. , DOI 10.1097/00000542-200203000-00011Rozenfeld, V., Cheng, J.W.M., The role of vasopressin in the treatment of vasodilation in shock states (2000) Annals of Pharmacotherapy, 34 (2), pp. 250-254Tanus-Santos, J.E., Gordo, W.M., Udelsmann, A., Cittadino, M.H., Moreno Jr., H., Nonselective endothelin-receptor antagonism attenuates hemodynamic changes after massive pulmonary air embolism in dogs (2000) Chest, 118 (1), pp. 175-179(2000) Small Animal Clinical Nutrition, , Hand MS, Thatcher CD, Rimillard RL, Roudebush P (eds.). 4th ed. Marceline (MO): WalsworthBartelstone, H.J., Nasmyth, P.A., Vasopressin potentiation of catecholamine actions in dog, rat, cat, and rat aortic strip (1965) Am J Physiol, 208, pp. 754-762Commarato, M.A., Lum, B.K.B., Cardiovascular interaction of amphetamine and ephedrine with norepinephrine and with vasopressin (1969) Eur J Pharmacol, 7, pp. 127-134Oliver, G., Schäfer, E.A., On the physiological action of extracts of pituitary body and certain other glandular organs (1895) J Physiol (London), 18, pp. 277-279László, F.A., László Jr., F., De Wied, D., Pharmacology and clinical perspectives of vasopressin antagonists (1991) Pharmacol Rev, 43, pp. 73-108Tayama, E., Ueda, T., Shojima, T., Akasu, K., Oda, T., Fukunaga, S., Akashi, H., Aoyagi, S., Arginine vasopressin is an ideal drug after cardiac surgery for the management of low systemic vascular resistant hypotension concomitant with pulmonary hypertension (2007) Interactive Cardiovascular and Thoracic Surgery, 6 (6), pp. 715-719. , http://icvts.ctsnetjournals.org/cgi/reprint/6/6/715?ck=nck, DOI 10.1510/icvts.2007.159624Wakatsuki, T., Nakaya, Y., Inoue, I., Vasopressin modulates K+-channel activities of cultured smooth muscle cells from porcine coronary artery (1992) Am J Physiol, 263, pp. H491-6Holmes, C.L., Walley, K.R., Arginine vasopressin in the treatment of vasodilatory septic shock (2008) Best Practice and Research: Clinical Anaesthesiology, 22 (2), pp. 275-286. , DOI 10.1016/j.bpa.2008.03.002, PII S1521689608000268Ertmer, C., Rehberg, S., Westphal, M., Vasopressin analogues in the treatment of shock states: Potential pitfalls (2008) Best Practice and Research: Clinical Anaesthesiology, 22 (2), pp. 393-406. , DOI 10.1016/j.bpa.2008.02.007, PII S1521689608000219Montani, J.P., Liard, J.F., Schoun, J., Mohring, J., Hemodynamic effects of exogenous and endogenous vasopressin at low plasma concentrations in conscious dogs (1980) Circulation Research, 47 (3), pp. 346-355Gaskill III, H.V., Sirinek, K.R., Levine, B.A., Hemodynamic effects of vasopressin: Can large doses be safely given? (1983) Arch Surg, 118, pp. 434-437Cowley Jr., A.W., Monos, E., Guyton, A.C., Interaction of vasopressin and baroreceptor reflex system in the regulation of arterial blood pressure in the dog (1974) Circ Res, 34, pp. 505-514Wagner, H.N., Braunwald, E., The pressor effect of the antidiuretic principle of the posterior pituitary in orthostatic hypotension (1956) J Clin Invest, 35, pp. 1412-1418Möhring, J., Glänzer, K., Maciel Jr., J.A., Dasing, R., Kramer, H.J., Arbogast, R., Greatly enhanced pressor response to antidiuretic hormone in patients with impaired cardiovascular reflexes due to idiopathic orthostatic hypotension (1980) J Cardiovasc Pharmacol, 2 (4), pp. 367-376Iwai, A., Sakano, T., Uenishi, M., Sugimoto, H., Yoshioka, T., Sugimoto, T., Effects of vasopressin and catecholamines on the maintenance of circulatory stability in brain-dead patients (1989) Transplantation, 48, pp. 613-617Luckner, G., Dünser, M.W., Jochberger, S., Mayr, V.D., Wenzel, V., Ulmer, H., Arginine vasopressin in 316 patients with advanced vasodilatory shock (2005) Crit Care Med, 33, pp. 2659-2666Westphal, M., Stubbe, H., Sielenkamper, A.W., Ball, C., Van Aken, H., Borgulya, R., Effects of titrated arginine vasopressin on hemodynamic variables and oxygen transport in healthy and endotoxemic sheep (2003) Crit Care Med, 31, pp. 1502-1508Leather, H.A., Segers, P., Berends, N., Vandermeersch, E., Wouters, P.F., Effects of vasopressin on right ventricular function in an experimental model of acute pulmonary hypertension (2002) Crit Care Med, 30, pp. 2548-255