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Systemic and regional hemodynamic effects of enalaprilat infusion in experimental normotensive sepsis
Rahal, L.;Garrido, A.G.;Cruz Jr., R.J.;Rocha e Silva, M.;Poli-de-Figueiredo, L.F.;
Brazilian Journal of Medical and Biological Research , 2006, DOI: 10.1590/S0100-879X2006000900008
Abstract: angiotensin-converting enzyme inhibitors have been shown to improve splanchnic perfusion in distinct shock states. we hypothesized that enalaprilat potentiates the benefits of early fluid resuscitation in severe experimental sepsis, particularly in the splanchnic region. anesthetized and mechanically ventilated mongrel dogs received an intravenous infusion of live escherichia coli over a period of 30 min. thereafter, two interventions were performed: fluid infusion (normal saline, 32 ml/kg over 30 min) and enalaprilat infusion (0.02 mg kg-1 min-1 for 60 min) in randomized groups. the following groups were studied: controls (fluid infusion, n = 4), e1 (enalaprilat infusion followed by fluid infusion, n = 5) and e2 (fluid infusion followed by enalaprilat infusion, n = 5). all animals were observed for a 120 min after bacterial infusion. mean arterial pressure, cardiac output (co), portal vein blood flow (pvbf), systemic and regional oxygen-derived variables, and lactate levels were measured. rapid and progressive reductions in co and pvbf were induced by the infusion of live bacteria, while minor changes were observed in mean arterial pressure. systemic and regional territories showed a significant increase in oxygen extraction and lactate levels. widening venous-arterial and portal-arterial pco2 gradients were also detected. fluid replacement promoted transient benefits in co and pvbf. enalaprilat after fluid resuscitation did not affect systemic or regional hemodynamic variables. we conclude that in this model of normotensive sepsis inhibition of angiotensin-converting enzyme did not interfere with the course of systemic or regional hemodynamic and oxygen-derived variables.
Systemic and regional hemodynamic effects of enalaprilat infusion in experimental normotensive sepsis  [cached]
Rahal L.,Garrido A.G.,Cruz Jr. R.J.,Rocha e Silva M.
Brazilian Journal of Medical and Biological Research , 2006,
Abstract: Angiotensin-converting enzyme inhibitors have been shown to improve splanchnic perfusion in distinct shock states. We hypothesized that enalaprilat potentiates the benefits of early fluid resuscitation in severe experimental sepsis, particularly in the splanchnic region. Anesthetized and mechanically ventilated mongrel dogs received an intravenous infusion of live Escherichia coli over a period of 30 min. Thereafter, two interventions were performed: fluid infusion (normal saline, 32 mL/kg over 30 min) and enalaprilat infusion (0.02 mg kg-1 min-1 for 60 min) in randomized groups. The following groups were studied: controls (fluid infusion, N = 4), E1 (enalaprilat infusion followed by fluid infusion, N = 5) and E2 (fluid infusion followed by enalaprilat infusion, N = 5). All animals were observed for a 120 min after bacterial infusion. Mean arterial pressure, cardiac output (CO), portal vein blood flow (PVBF), systemic and regional oxygen-derived variables, and lactate levels were measured. Rapid and progressive reductions in CO and PVBF were induced by the infusion of live bacteria, while minor changes were observed in mean arterial pressure. Systemic and regional territories showed a significant increase in oxygen extraction and lactate levels. Widening venous-arterial and portal-arterial pCO2 gradients were also detected. Fluid replacement promoted transient benefits in CO and PVBF. Enalaprilat after fluid resuscitation did not affect systemic or regional hemodynamic variables. We conclude that in this model of normotensive sepsis inhibition of angiotensin-converting enzyme did not interfere with the course of systemic or regional hemodynamic and oxygen-derived variables.
Comparison of the effects of lactated Ringer solution with and without hydroxyethyl starch fluid resuscitation on gut edema during severe splanchnic ischemia
Lobo, S.M.;Orrico, S.R.P.;Queiroz, M.M.;Contrim, L.M.;Cury, P.M.;
Brazilian Journal of Medical and Biological Research , 2008, DOI: 10.1590/S0100-879X2008000700014
Abstract: the type of fluid used during resuscitation may have an important impact on tissue edema. we evaluated the impact of two different regimens of fluid resuscitation on hemodynamics and on lung and intestinal edema during splanchnic hypoperfusion in rabbits. the study included 16 female new zealand rabbits (2.9 to 3.3 kg body weight, aged 8 to 12 months) with splanchnic ischemia induced by ligation of the superior mesenteric artery. the animals were randomized into two experimental groups: group i (n = 9) received 12 ml·kg-1·h-1 lactated ringer solution and 20 ml/kg 6% hydroxyethyl starch solution; group ii (n = 7) received 36 ml·kg-1·h-1 lactated ringer solution and 20 ml/kg 0.9% saline. a segment from the ileum was isolated to be perfused. a tonometric catheter was placed in a second gut segment. superior mesenteric artery (qsma) and aortic (qaorta) flows were measured using ultrasonic flow probes. after 4 h of fluid resuscitation, tissue specimens were immediately removed for estimations of gut and lung edema. there were no differences in global and regional perfusion variables, lung wet-to-dry weight ratios and oxygenation indices between groups. gut wet-to-dry weight ratio was significantly lower in the crystalloid/colloid-treated group (4.9 ± 1.5) than in the crystalloid-treated group (7.3 ± 2.4) (p < 0.05). in this model of intestinal ischemia, fluid resuscitation with crystalloids caused more gut edema than a combination of crystalloids and colloids.
Is PEEP detrimental to splanchnic perfusion in mechanically ventilated patients?
M Myc, J Jastrzebski
Critical Care , 2006, DOI: 10.1186/cc4364
Abstract: A prospective study.Department of Anesthesiology and Intensive Care of Medical Postgraduate Education Center, Warsaw, Poland.Twenty adult ICU patients after laparotomy (hemicolec-tomy, colectomy) (group A) and five nonsurgical ICU patients (group B). All of them did not have serious respiratory and circulatory abnormalities, and did not need adrenergic or any circulatory support. All were mechanically ventilated under sedation with PEEP 0, PEEP 5, PEEP 10, PEEP 15. Each patient ventilated with PEEP 0 was a control for himself/herself. Each ventilation setting period lasted 1 hour. All the measurements were performed twice during that time.PiCO2-PaCO2, pH-pHi, CI, CVP, ITBVI, EVLWI were measured using gastric tonometry and the PiCCO method (pulse contour cardiac output) after each change of PEEP value. No differences in pH-pHi and PiCO2-PaCO2 were observed between groups A and B. PEEP does not compromise gastric mucosal perfusion, as assessed by tonometry. Even the patient's age was not essential. A decrease in cardiac output did not result in necessity of adrenergic support. Only in one case there was a need to use it for more than 1 hour after setting PEEP 10. Mean values of CI were higher in group A compared with nonoperated group B. CI depends on the age and PEEP level. CVP was increased by PEEP in both groups, but ITBVI was almost untouched, the right ventricle preload did not decrease, and EVLWI was slightly lowered under PEEP 15. IAP did not exceed 10 mmHg in any case.PEEP up to 15 cmH2O is well tolerated by the majority of ICU patients. The results of the present study indicate that incremental increases in PEEP do not impact on splanchnic perfusion as assessed by gastric tonometry in patients with adequate fluid loading. In some cases a necessity for adrenergic support might appear. Facing the fact of nonaffecting splanchnic perfusion, we cannot recommend any PEEP value as ideal for perfusing that region. More studies are needed in this area, particularly in
Effects of an angiotensin II antagonist on organ perfusion during the post-resuscitation phase in pigs
Hans-Ulrich Strohmenger, Karl H Lindner, Wolfgang Wienen, Peter Radermacher
Critical Care , 1998, DOI: 10.1186/cc125
Abstract: Five minutes after ROSC in the TELM group, blood flow in the cortex and myocardium increased to 583% (P < 0.05) and 137% (not significant), respectively, whereas blood flow of the colon, stomach and pancreas decreased to 50% (P < 0.05), 28% (P < 0.05) and 19% (P < 0.05) of pre-arrest values, respectively. At 90 min after ROSC, pre-arrest perfusion values both in non-splanchnic and splanchnic organs were achieved. At no point in time were there significant differences between the two groups with respect to organ blood flow or speed of recovery of organ perfusion.During the post-resuscitation phase, organ blood flow is characterized by the coincidence of increased cerebral and myocardial blood flow and decreased intestinal blood flow. Administration of TELM 10 min after ROSC did not improve the recovery of organ perfusion.In an effort to improve the dismal outcome of cardiac arrest, a variety of vasopressor agents have been investigated in animal models and in humans [1,2,3]. In particular, in a porcine model of ventricular fibrillation, administration of vasopressin led to a significantly higher coronary perfusion pressure and myocardial blood flow than high dose epinephrine [3]. Vasopressin, however, is reported to be a potent splanchnic vasoconstrictor which leads to a disproportionate reduction in mesenteric blood flow [4,5]. In addition, activation of the renin-angiotensin system has been shown to be part of the neuroendocrine response to cardiac arrest [6,7] or severe systemic hypotension [4,8], and angiotensin II (ANG II) mediates highly selective and potent splanchnic vasoconstriction [4,8,9]. During hemorrhagic or cardiogenic shock, blockade of the renin-angiotensin axis has been shown to abolish selective splanchnic vasoconstriction [10,11,12]. However, blockade of the renin-angiotensin axis during the immediate post-resuscitation phase has not yet been evaluated. The purpose of this study was to compare splanchnic and non-splanchnic organ perfusion pre-arre
Comparison of effects of uncomplicated canine babesiosis and canine normovolaemic anaemia on abdominal splanchnic Doppler characteristics - a preliminary investigation  [cached]
L.M. Koma,R.M. Kirberger,A.L. Leisewitz,L.S. Jacobson
Journal of the South African Veterinary Association , 2012, DOI: 10.4102/jsava.v76i3.415
Abstract: A preliminary study was conducted to compare uncomplicated canine babesiosis (CB) and experimentally induced normovolaemic anaemia (EA) using Doppler ultrasonography of abdominal splanchnic vessels. Fourteen dogs with uncomplicated CB were investigated together with 11 healthy Beagles during severe EA, moderate EA and the physiological state as a control group. Canine babesiosis was compared with severe EA, moderate EA and the physiological state using Doppler variables of the abdominal aorta, cranial mesenteric artery (CMA), coeliac, left renal and interlobar, and hilar splenic arteries, and the main portal vein. Patterns of haemodynamic changes during CB and EA were broadly similar and were characterised by elevations in velocities and reductions in resistance indices in all vessels except the renal arteries when compared with the physiological state. Aortic and CMA peak systolic velocities and CMA end diastolic and time-averaged mean velocities in CB were significantly lower (P < 0.023) than those in severe EA. Patterns of renal haemodynamic changes during CB and EA were similar. However, the renal patterns differed from those of aortic and gastrointestinal arteries, having elevations in vascular resistance indices, a reduction in end diastolic velocity and unchanged time-averaged mean velocity. The left renal artery resistive index in CB was significantly higher (P < 0.025) than those in EA and the physiological state. Renal interlobar artery resistive and pulsatility indices in CB were significantly higher (P < 0.016) than those of moderate EA and the physiological state. The similar haemodynamic patterns in CB and EA are attributable to anaemia, while significant differencesmayadditionally be attributed to pathophysiological factors peculiar to CB.
Complications after Dipyridamole Infusion in Myocardial Perfusion SPECT and Correlation with Homodynamic Changes
S.R. Zakavi,A. Taghizadeh-Kermani,K. Aryana,M. Taherpour
Iranian Journal of Nuclear Medicine , 2006,
Abstract: Introduction: In Iran dipyridamole is the main agent used for coronary dilatation before myocardial perfusion SPECT. This study tries to evaluate the side effects after dipyridamole infusion and its relation with hemodynamic changes. Methods: We studied 300 patients who referred to myocardial perfusion scan. The exclusion criteria were: 1) AV block degree 2 or more, 2) Asthma 3) Sick sinus syndrome 4) LV EF0.08). Conclusion: After dipyridamole infusion, nonspecific side effects are frequent. Headache and flashing is more frequent in female patients. Flashing is related to decrement in diastolic blood pressure.
Clinical review: Splanchnic ischaemia
Stephan M Jakob
Critical Care , 2002, DOI: 10.1186/cc1515
Abstract: Under conditions of low systemic blood flow or haemorrhage, perfusion of vital organs is maintained at the expense of perfusion of visceral organs [1,2,3]. If blood flow to the splanchnic tissues is sufficiently low, ischaemia and (if it is prolonged) tissue damage and necrosis may occur. As a result of splanchnic ischaemia the gut may become permeable, and endotoxin and other bacterial products can pass through the gut wall into lymph nodes and blood vessels [4,5], thereby causing injury to local and distant organs [6,7]. The splanchnic organs may also be at risk in septic shock, even when splanchnic blood flow is normal or elevated, because of a major increase in metabolic demand [8,9].There are only a few methods with which to measure splanchnic perfusion in the clinical setting, and interpretation of the obtained results can be difficult. Once detected, the treatment of splanchnic ischaemia is not straightforward [10]. There is no drug available that selectively improves splanchnic perfusion in a clinically significant way. On the other hand, a number of drugs may actually worsen splanchnic perfusion and/or metabolism [11,12].The present review discusses important pathophysiological aspects of splanchnic vasoregulation and presents recently published experimental and clinical trials in the field of impaired splanchnic blood flow and metabolism.A number of studies have demonstrated disproportionately impaired perfusion of the gut and colon in low-flow states [1,2,3,13,14,15]. However, redistribution of blood flow away from the splanchnic organs has been demonstrated mainly in experimental haemorrhagic shock. We [16] and others [17] have provided evidence that blood flow to the splanchnic region is reduced in proportion to systemic blood flow under different conditions of low cardiac output. Varying study conditions and consequent pathophysiological reactions may explain these inconsistent findings. Nevertheless, there is evidence that even a reduction in splanchn
Changes of splanchnic perfusion after applying positive end expiratory pressure in patients with acute respiratory distress syndrome  [cached]
Sarkar Suman,Bhattacharya Prithwis,Kumar Indrajit,Mandal Kruti
Indian Journal of Critical Care Medicine , 2009,
Abstract: Background: Positive end-expiratory pressure (PEEP) improves oxygenation and can prevent ventilator- induced lung injury in patients with acute respiratory distress syndrome (ARDS). Nevertheless, PEEP can also induce detrimental effects by its influence on the cardiovascular system. The purpose of this study was to assess the effects of PEEP on gastric mucosal perfusion while applying a protective ventilatory strategy in patients with ARDS. Materials and Methods: Thirty-two patients were included in the study. A pressure-volume curve was traced and ideal PEEP, defined as lower inflection point + 2cmH 2 O, was determined. Gastric tonometry was measured continuously (Tonocap). After baseline measurements, 10, 15 and 20cmH 2 O PEEP and ideal PEEP were applied for 30 min each. By the end of each period, hemodynamics, CO 2 gap (gastric minus arterial partial pressures), and ventilatory measurements were taken. Results: PEEP had no effect on CO 2 gap (median [range], baseline: 18 [2-30] mmHg; PEEP 10: 18 [0-40] mmHg; PEEP 15: 17 [0-39] mmHg; PEEP 20: 16 [4-39] mmHg; ideal PEEP: 19 [9-39] mmHg; P = 0.19). Cardiac index also remained unchanged (baseline: 4.7 [2.6-6.2] l min 1 m 2 ; PEEP 10: 4.4 [2.5-7] l min 1 m 2 ; PEEP 15: 4.4 [2.2-6.8] l min 1 m 2 ; PEEP 20: 4.8 [2.4-6.3] l min 1 m 2 ; ideal PEEP: 4.9 [2.4-6.3] l min 1 m 2 ; P = 0.09). Conclusion: PEEP of 10-20 cmH 2 O does not affect splanchnic perfusion and is hemodynamically well tolerated in most patients with ARDS, including those receiving inotropic supports.
Assessment of splanchnic perfusion with gastric tonometry in the immediate postoperative period of cardiac surgery in children
Souza, Renato Lopes de;Carvalho, Werther Brunow de;Maluf, Miguel Angel;Carvalho, Antonio Carlos;
Arquivos Brasileiros de Cardiologia , 2001, DOI: 10.1590/S0066-782X2001001200002
Abstract: objective - a prospective, nonrandomized clinical study to assess splanchnic perfusion based on intramucosal ph in the postoperative period of cardiac surgery and to check the evolution of patients during hospitalization. methods - we studied 10 children, during the immediate postoperative period after elective cardiac surgery. sequential intramucosal ph measurements were taken, without dobutamine (t0) and with 5mcg/kg/min (t1) and 10 (t2) mcg/kg/min. in the pediatric intensive care unit, intramucosal ph measurements were made on admission and 4, 8, 12, and 24 hours thereafter. results - the patients had an increase in intramucosal ph values with dobutamine 10mcg/kg/min [7.19± 0.09 (t0), 7.16±0.13(t1), and 7.32±0.16(t2)], (p=0.103). during the hospitalization period, the intramucosal ph values were the following: 7.20±0.13 (upon admission), 7.27±0.16 (after 4 hours), 7.26±0.07 (after 8 hours), 7.32±0.12 (after 12 hours), and 7.38±0.08 (after 24 hours), (p=0.045). no deaths occurred, and none of the patients developed multiple organ and systems dysfunction. conclusion - an increase in and normalization of intramucosal ph was observed after dobutamine use. measurement of intramucosal ph is a type of monitoring that is easy to perform and free of complications in children during the postoperative period of cardiac surgery.
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