ACG Clinical Guideline: disorders of the hepatic and mesenteric circulation

Disorders of the mesenteric, portal, and hepatic veins and mesenteric and hepatic arteries have important clinical consequences and may lead to acute liver failure, chronic liver disease, noncirrhotic portal hypertension, cirrhosis, and hepatocellular carcinoma. Although literature in the field of vascular liver disorders is scant, these disorders are common in clinical practice, and general practitioners, gastroenterologists, and hepatologists may benefit from expert guidance and recommendations for management of these conditions. These guidelines represent the official practice recommendations of the American College of Gastroenterology. Key concept statements based on author expert opinion and review of literature and specific recommendations based on PICO/GRADE analysis have been developed to aid in the management of vascular liver disorders. These recommendations and guidelines should be tailored to individual patients and circumstances in routine clinical practice.

Ischemia modified albumin: does it change during pneumoperitoneum in robotic prostatectomies?

ABSTRACT Background The unique positioning of the patient at steep Trendelenburg with prolonged and increased intra-abdominal pressure (IAP) during robotic radical prostatectomy may increase the risk of splanchnic ischemia. We aimed to investigate the acute effects of IAP and steep Trendelenburg position on the level of ischemia modified albumin (IMA) and to test if serum IMA levels might be used as a surrogate marker for possible covert ischemia during robotic radical prostatectomies. Patients and Methods Fifty ASA I-II patients scheduled for elective robotic radical prostatectomy were included in this investigation. Exclusion criteria The patients were excluded from the study when an arterial cannulation could not be accomplished, if the case had to be converted to open surgery or if the calculated intraoperative bleeding exceeded 300ml. All the patients were placed in steep (45 degrees) Trendelenburg position following trocar placement. Throughout the operation the IAP was maintained between 11-14mmHg. Mean arterial blood pressure (MAP), cardiac output (CO) were continuously monitored before the induction and throughout the surgery. Blood gases, electrolytes, urea, creatinine, alanine transferase (ALT), aspartate transferase (AST) were recorded. Additionally, IMA levels were measured before, during and after surgery. Results (1) MAP, CO, lactate and hemoglobin (Hb) did not significantly change in any period of surgery (p>0.05); (2) sodium (p<0.01), potassium (p<0.05) and urea (p<0.05) levels decreased at postoperative period, and no significant changes at creatinine, AST, ALT levels were observed in these patients; (3) At the end of surgery (180 min) pCO2, pO2, HCO3 and BE did not change compared to after induction values (p>0.05) but mild acidosis was present in these patients (p<0.01 vs. after induction); (4) IMA levels were found to be comparable before induction (0.34±0.04), after induction (0.31±0.06) ...

Abdomen y corazón ¿El primer paso del síndrome cardiorrenal? / Abdomen and heart The first step of the cardiorenal syndrome?

A pesar de los grandes avances en la cardiología en el siglo XX y XXI, la insuficiencia cardiaca sigue suponiendo la principal causa de hospitalización en las personas ancianas y presentando un pronóstico ominoso. Además, a pesar de los múltiples estudios sobre nuevas dianas farmacológicas, apenas hemos avanzado en el campo del tratamiento, tal vez porque aún existen lagunas en su fisiopatología. No debemos olvidar que la insuficiencia cardiaca es un compendio de signos y síntomas que engloban múltiples órganos y sistemas. Mucho se está investigando sobre la relación entre riñón y corazón en forma de síndrome cardiorrenal. Algo cada vez más en boga es el papel del abdomen en la disfunción orgánica de la insuficiencia cardiaca. En ese sentido, el sistema venoso contiene el 70 por ciento del volumen sanguíneo, siendo almacenado en su mayor parte dentro de las vísceras abdominales. Un aumento del tono simpático supone aumento intenso del retorno venoso tan importante como para aumentar las presiones de llenado y justificar una descompensación cardíaca. La congestión sistémica determina un aumento en la presión intraabdominal que está correlacionada con la disfunción renal en la insuficiencia cardíaca avanzada. La hipoperfusión tisular intestinal supone microtraslocación bacteriana promoviendo el status proinflamatorio típico de este síndrome. La visión holística e integrada de la insuficiencia cardiaca puede suponer un avance tanto en la estratificación del riesgo como en las estrategias terapéuticas. Grandes pasos se están dando en este sentido con estudios sobre la ultrafiltración, paracentesis, diálisis peritoneal, suero hipertónico o fármacos adsorbentes del sodio.(AU)

Despite the great progress in Cardiology during the last century, heart failure keeps being the main cause of hospitalization among elderly, with an awful prognosis. In spite of multiple studies about drug targets, we have hardly made progress regarding the treatment, maybe because there are gaps concerning physiopathology. Heart failure is a set of signs and symptoms encompassing multiple organs and systems. Lots of studies about cardiorenal syndrome are being published. In this sense, abdominal contribution to organic dysfunction in heart failure is becoming a rising topic. Therefore, venous system contains 70 percent of the total blood volume, mostly in splanchnic capacitance veins. Sympathetic stimulation suppose an important shift of blood from splanchnic veins to effective circulatory volume, rising increasing filling pressures and justifying acute decompensated heart failure. Systemic congestion may lead to a state of increased intra-abdominal pressure which is correlated with renal dysfunction in advanced heart failure. Tisular hypoperfusion leads to bacterial translocation triggering systemic inflammation typical of heart failure. This holyistic vision may suppose an important progress on risk stratification and treatment strategies. Among those under investigation are ultrafiltration, paracentesis peritoneal dialyisis, hypertonic saline or oral sodium binders.(AU)

Effect of protective solutions and hydroxyethyl starch in the attenuation of the injuries of ischemia and reperfusion of splanchnic organs

PURPOSE: Vogt´s antioxidant solution (red blood cells, Ringer's solution, sodium bicarbonate, mannitol, allopurinol and 50% glucose) or its modification including hydroxyethyl starch (HES) were tested for the prevention of splanchnic artery occlusion shock. METHODS: Seventy rats were distributed in treatment (3), control (1), and sham (3) groups. Ischemia and reperfusion were induced by celiac, superior mesenteric and inferior mesenteric arteries occlusion for 40 min, followed by 60 min reperfusion or sham procedures. Controls received saline, both treatment and sham groups received the Vogt's solution, modified Vogt's solution (replacing Ringer's solution by HES), or HES. Mean arterial blood pressure (MABP), ileal malondialdehyde (MDA) and plasmatic MDA were determined, and a histologic grading system was used. RESULTS: At reperfusion, MABP dropped in all I/R groups. Only HES treatment was able to restore final MABP to the levels of sham groups. Plasmatic MDA did not show differences between groups. Ileum MDA was significantly higher in the control and treatment groups as compared to the sham group. Histology ranking was higher in the only in control group. CONCLUSIONS: Hydroxyethyl starch was able to prevent hemodynamic shock but not intestinal lesions. Both treatments with Vogt's solutions did not show any improvement. .

Mesenteric hypoperfusion and inflammation induced by brain death are not affected by inhibition of the autonomic storm in rats

OBJECTIVES: Brain death is typically followed by autonomic changes that lead to hemodynamic instability, which is likely associated with microcirculatory dysfunction and inflammation. We evaluated the role of the microcirculation in the hemodynamic and inflammatory events that occur after brain death and the effects of autonomic storm inhibition via thoracic epidural blockade on mesenteric microcirculatory changes and inflammatory responses. METHODS: Male Wistar rats were anesthetized and mechanically ventilated. Brain death was induced via intracranial balloon inflation. Bupivacaine (brain death-thoracic epidural blockade group) or saline (brain death group) infusion via an epidural catheter was initiated immediately before brain death induction. Sham-operated animals were used as controls (SH group). The mesenteric microcirculation was analyzed via intravital microscopy, and the expression of adhesion molecules was evaluated via immunohistochemistry 180 min after brain death induction. RESULTS: A significant difference in mean arterial pressure behavior was observed between the brain death-thoracic epidural blockade group and the other groups, indicating that the former group experienced autonomic storm inhibition. However, the proportion of perfused small vessels in the brain death-thoracic epidural blockade group was similar to or lower than that in the brain death and SH groups, respectively. The expression of intercellular adhesion molecule 1 was similar between the brain death-thoracic epidural blockade and brain death groups but was significantly lower in the SH group than in the other two groups. The number of migrating leukocytes in the perivascular tissue followed the same trend for all groups. CONCLUSIONS: Although thoracic epidural blockade effectively inhibited the autonomic storm, it did not affect mesenteric hypoperfusion or inflammation induced by brain death. .

Crohn's disease activity assessed by doppler sonography: the role of aortic flow parameters

OBJECTIVES: Intestinal neovascularization and abnormal abdominal arterial flow rates have been reported in Crohn's disease. The aim of this study was to evaluate Doppler sonography as a method for assessing Crohn's disease activity based on changes in splanchnic hemodynamics. METHODS: Forty-eight patients with Crohn's disease, 22 healthy volunteers and 12 patients with irritable bowel syndrome were evaluated by Doppler ultrasound for flow parameters of the aorta and superior mesenteric artery. This evaluation included the cross-sectional area, maximum flow volume, peak systolic velocity, end diastolic velocity, resistance and the pulsatility index. Disease activity was classified according to the Crohn's disease activity index. RESULTS: Most measurements in the aorta and superior mesenteric artery were significantly different between Crohn's disease patients and both control groups. Only the aortic maximum flow volume (CC = 0.37, p = 0.009) and aortic peak systolic velocity (CC = 0.30, p = 0.035) showed a significant positive correlation with the Crohn's disease activity index. The determination of cut-off points for the aortic maximum flow volume and peak systolic velocity measurements increased the sensitivity (80 and 75% for flow volume and velocity, respectively), specificity (57 and 75%), accuracy (67 and 75%) and positive (57 and 68%) and negative (80 and 81%) predictive values. These cut-off values permitted the correct classification of most of the patients with Crohn's disease with respect to disease activity. None of the superior mesenteric artery measurements were able to discriminate patients in relation to disease activity. CONCLUSION: The aortic maximum flow volume and peak systolic velocity levels estimated by Doppler sonography reflected disease activity in Crohn's disease. Doppler sonography of the aorta is therefore a novel noninvasive adjunct method that may be ...

Paradoxical effects of brain death and associated trauma on rat mesenteric microcirculation: an intravital microscopic study

OBJECTIVE: Experimental findings support clinical evidence that brain death impairs the viability of organs for transplantation, triggering hemodynamic, hormonal, and inflammatory responses. However, several of these events could be consequences of brain death-associated trauma. This study investigated microcirculatory alterations and systemic inflammatory markers in brain-dead rats and the influence of the associated trauma. METHOD: Brain death was induced using intracranial balloon inflation; sham-operated rats were trepanned only. After 30 or 180 min, the mesenteric microcirculation was observed using intravital microscopy. The expression of Pselectin and ICAM-1 on the endothelium was evaluated using immunohistochemistry. The serum cytokine, chemokine, and corticosterone levels were quantified using enzyme-linked immunosorbent assays. White blood cell counts were also determined. RESULTS: Brain death resulted in a decrease in the mesenteric perfusion to 30 percent, a 2.6-fold increase in the expression of ICAM-1 and leukocyte migration at the mesentery, a 70 percent reduction in the serum corticosterone level and pronounced leukopenia. Similar increases in the cytokine and chemokine levels were seen in the both the experimental and control animals. CONCLUSION: The data presented in this study suggest that brain death itself induces hypoperfusion in the mesenteric microcirculation that is associated with a pronounced reduction in the endogenous corticosterone level, thereby leading to increased local inflammation and organ dysfunction. These events are paradoxically associated with induced leukopenia after brain damage.

Isquemia mesentérica / Mesenteric ischemia

Debido a la alta incidencia y graves consecuencias que produce, la isquemia mesentérica representa un reto para el terapeuta que la enfrenta. Las consecuencias fisiopatológicas que comprometen muy rápido todo el sistema orgánico, hacen de su diagnóstico precoz no sólo un reto sino la clave del éxito en su manejo. Esta revisión pretende describir en detalle las características de la circulación esplácnica y así mismo revisa las principales estrategias diagnósticas y su manejo.

Mesenteric ischemia is a significant challenge for clinicians because of its high incidence and serious consequences. The pathophysiologic consequences which rapidly involve the entire organ system make its early diagnosis not only a challenge but the key to successful management. This review intends to thoroughly describe the splanchnic circulation and reviews mayor diagnostic and management strategies.

Ischemia-reperfusion histopathology alterations of the rabbit intestinal wall with and without exclusion of the collateral mesenteric circulation supply / Alterações histopatológicas da parede intestinal de coelhos na isquemia-reperfusão com e sem exclusão da circulação mesentérica colateral

PURPOSE: To evaluate the histopathology alterations of the intestinal mucosa of rabbits submitted to different times of mesenteric artery ischemia and reperfusion with and without celiac artery collateral circulation supply. METHODS: Two groups of eight male New Zealand white rabbits (weight 2.2-3.5 kg) were used in this study. In the Group 1 animals, the proximal mesenteric artery was occluded for 60 min with an atraumatic vascular clamp, followed by reperfusion for 60 min. In the Group 2 animals the small bowel and mesentery were cut 30cm and 60cm far from the gastroduodenal pyloric transition before the proximal mesenteric artery occlusion. Small bowel biopsies were obtained before ischemia (control), after 30 min and 60 min of mesenteric ischemia and at 30 and 60 min. of mesenteric artery reperfusion. RESULTS: In the Group I animals, the followings histopathology grade results were observed: t1, mean 0.4 + 0.29; t2, mean 1.9 ± 0.38; t3, 1.9 ± 0.33; t4, 1.2 ± 0.36 and t5, 1.2 ± 0.32. Differences between t0 and t2 and between t3 and t4 were statistically significant (p<0.05). Differences between t2 and t3 and t4 and t5 were not significant (p>0.5). In the Group II animals, it was observed: t1, mean 1.6 ± 0.33; t2, 2.4 ± 0.36; t3, 3.0 ± 0.35; t4 3.4 ± 0.31; t5, 3 ± 031. Differences between t0 and t1, t1 and t2, and t2 and t3 were significant (p<0.05). Differences between histopathology grades results of samples t1 to t5 in Group 1 and 2 were statistically significant (p<0.5). CONCLUSION: Microscopic examination of the biopsies revealed significant evidence of worse small bowel wall ischemia-reperfusion lesions by exclusion of the celiac artery collateral circulation supply.

OBJETIVO: Avaliar as alterações histopatológicas da mucosa intestinal de coelhos submetidos à isquemia-reperfusão com e sem exclusão da circulação mesentérica colateral. MÉTODOS: Foram estudados dois grupos de oito coelhos Nova Zelândia machos com pesos variáveis entre 2,2 e 3,5 kg de peso corpóreo. Nos animais do Grupo 1, a artéria mesentérica proximal foi ocluida por pinçamento atraumático durante 60 min, seguido de reperfusão por 60 min. No Grupo 2 o intestino delgado e o mesentério foram seccionados 30 cm e 60 após a transição pilórica gastroduodenal antes da oclusão da artéria mesentérica cranial. Biópsias da parede intestinal foram obtidas antes da isquemia (controle), após 30 e 60 min. de isquemia. RESULTADOS: No Grupo I foram observados os seguintes graus de lesões: t1,média de 0.4 + 0.29; t2, média 1.9 ± 0.38; t3, 1.9 ± 0.33; t4, 1.2 ± 0.36 e t5, 1.2 ± 0.32. As diferenças entre t0 e t2 e entre t3 e t4 foram significantes (p<0.05). As diferenças entre t2 e t3 e t4 e t5 não foram significantes (p>0.5). No Group II observou-se: t1, média de 1.6 ± 0.33; t2, 2.4 ± 0.36; t3, 3.0 ± 0.35; t4 3.4 ± 0.31; t5, 3 ± 031. As diferenças entre t0 e t1, t1 e t2, e t2 e t3 foram significantes (p<0.05). As diferenças entre os resultados histopatológicos das biopsies de t1 a t5 dos Grupos 1 e 2 foram significantes (p<0.5). CONCLUSÃO: A exclusão da circulação mesentérica colateral agravou significantemente a degeneração histopatológica na isquemia-reperfusão da parede intestinal.

Tratamiento quirúrgico del aneurisma del tronco celíaco, reporte de un caso / Surgical treatment of aneurysm of the celiac trunk: case report

Los aneurismas del tronco celíaco son un problema clínico infrecuente. La mayoría de los pacientes son sintomáticos al momento del diagnóstico; sin embargo, ocasionalmente se detectan de manera incidental durante estudios imagenológicos para otras enfermedades. Se presenta el caso de un paciente de 54 años con aneurisma sintomático del tronco celíaco, diagnosticado por tomografía e intervenido quirúrgicamente de manera satisfactoria.

Aneurysm of the celiac artery is an uncommon clinical problem; fewer than 180 cases have been reported in the world's medical literature. Most patients are symptomatic at the time of diagnosis. However, occasionally such aneurysms are detected incidentally during diagnostic imaging for other diseases. We present of a 54 years-old man who had a symptomatic celiac artery aneurysm detected by Computed tomography. The patient underwent successful resection of the aneurysm and revascularization of the celiac artery – common hepatic and splenic arteries with use of an PTFE graft.

Systemic evaluation on ischemia and reperfusion injury of splanchnic organs in rats / Alterações sistêmicas na isquemia e reperfusão de órgãos esplâncnicos em ratos

PURPOSE: To evaluate hemodynamic and systemic changes during and after splanchnic ischemia and reperfusion (I/R). METHODS: Rats were divided into two groups: a) control: animals submitted to surgery, but not to I/R, treated with saline (5 ml/kg/h) for 150 min; b) group I/R: animals continuously infused with saline, and submitted to occlusion of the celiac trunk, superior mesenteric artery (SMA), and inferior mesenteric artery for 30 min, followed by a 120-min reperfusion. Mean arterial blood pressure (MABP), venous pressure, aortic and SMA blood flow, heart rate, esophageal temperature and hematocrit were evaluated. RESULTS: During reperfusion in I/R groups, there was a progressive decrease in MABP, aortic blood flow, SMA blood flow, heart rate and esophageal temperature; vein pressure and hematocrit remained unchanged during the experiment. CONCLUSION: The model of ischemia used causes systemic changes, which are evidenced by hypotension, decrease in mesenteric blood flow, heart rate and esophageal temperature.

OBJETIVO: Avaliar as alterações hemodinâmicas e sistêmicas decorrentes de isquemia e reperfusão (I/R) esplâncnica em ratos. MÉTODOS: Vinte ratos foram divididos em dois grupos: grupo controle: os animais foram submetidos à cirurgia, mas não a I/R e foram tratados com solução fisiológica (5 ml/kg/h) por 150 minutos; grupo I/R: os animais foram submetidos à administração contínua de solução fisiológica e à oclusão do tronco celíaco, artéria mesentérica superior e artéria mesentérica inferior por 30 minutos, seguidos por 120 minutos de reperfusão. Avaliou-se a pressão arterial média, pressão venosa, fluxo sangüíneo na aorta e na artéria mesentérica superior, freqüência cardíaca, temperatura esofágica e hematócrito. RESULTADOS: Durante a reperfusão, no grupo I/R, houve uma diminuição progressiva da pressão arterial média, fluxo sangüíneo na aorta e artéria mesentérica superior, freqüência cardíaca e temperatura esofágica; pressão venosa e hematócrito não sofreram alteração. CONCLUSÃO: O modelo de isquemia provocado por oclusão da artéria mesentérica superior, artéria mesentérica inferior e tronco celíaco por 30 minutos seguidos por 120 minutos de reperfusão provoca alterações sistêmicas evidenciadas por hipotensão, diminuição do fluxo sangüíneo mesentérico, da freqüência cardíaca e da temperatura esofágica.

Peculiaridades da circulação mesentérica em recém-nascidos e suas implicações em doenças gastrintestinais do período neonatal: [revisão] / Mesenteric circulation peculiarities in infant newborns and its implications in gastrointestinal illnesses of the neonatal period: [review]

OBJETIVO:Descrever peculiaridades da circulação mesentérica neonatal e caracterizar fatores de suscetibilidade ao desenvolvimento de doenças gastrintestinais e alterações do fluxo sanguíneo da artéria mesentérica superior por meio da dopplerfluxometria. FONTES DE DADOS: Livros-textos e publicações indexadas no Medline e SciELO nos últimos 20 anos, utilizando-se as palavras chaves: "mesenteric artery", "superior mesenteric artery", "newborn intestinal circulation", "necrotizing enterocolitis", "doppler flow velocimetry". SÍNTESE DOS DADOS: Alterações do fluxo sanguíneo mesentérico são um dos fatores predisponentes da enterocolite necrosante, doença neonatal de alta morbimortalidade que acomete principalmente prematuros. A circulação mesentérica é peculiar no período neonatal tanto em relação ao seu estado basal, quanto à sua resposta frente a estímulos fisiológicos. Variações da irrigação mesentérica podem ser inerentes à própria fase de desenvolvimento vascular intestinal do recém-nascido pré-termo, com possíveis agravos de fatores perinatais como: insuficiência placentária, asfixia, infecção, cateterismo umbilical, drogas (indometacina e cafeína), fototerapia, alimentação artificial e progressão rápida da dieta. A dopplerfluxometria permite o estudo da irrigação de órgãos-alvo e pode quantificar o fluxo sanguíneo, a resistência vascular e predizer situações de risco para doenças do trato gastrintestinal no período neonatal. CONCLUSÕES: O recém-nascido apresenta peculiaridades de irrigação sanguínea gastrintestinal. A dopplerfluxometria da artéria mesentérica superior é um método não invasivo que determina as condições circulatórias no território intestinal.

OBJECTIVE:To describe peculiarities of the neonatal mesenteric circulation and to characterize the susceptibility factors to the development of gastrointestinal illnesses and alterations of the superior mesenteric artery flow by the Doppler ultrasound method. DATA SOURCES: Textbooks and publications listed in Medline and SciELO from the last 20 years were searched using the key-words: "mesenteric artery", "intestinal superior mesenteric artery", "newborn circulation", "necrotizing enterocolitis", and "Doppler flow velocimetry". DATA SYNTHESIS: Alterations in the mesenteric flow are predisposing factors for necrotizing enterocolitis, which is a neonatal illness with high morbidity and mortality that occurs mainly in premature infants. The mesenteric circulation is peculiar at the neonatal period regarding its baseline status as well as its response from physiological stimulation. Mesenteric irrigation varies according to the proper phase of intestinal vascular development. Mesenteric irrigation can be damaged by perinatal factors, such as placental insufficiency, asphyxia, infection, umbilical catheters, drugs (indomethacin and caffeine), phototherapy, artificial feeding and fast diet progression. Doppler flow velocimetry allows the study of gut irrigations and may quantify blood flow and vascular resistance. The exam can predict risk situations for gastrointestinal illnesses during the neonatal period. CONCLUSIONS: The newborn infant presents peculiarities on gastrointestinal blood circulation. Superior mesenteric artery Doppler ultrasound provides non-invasive measures of the intestinal circulatory conditions.

Effects of different peep levels on mesenteric leukocyte-endothelial interactions in rats during mechanical ventilation

INTRODUCTION: Mechanical ventilation with positive end expiratory pressure (PEEP) improves oxygenation and treats acute pulmonary failure. However, increased intrathoracic pressure may cause regional blood flow alterations that may contribute to mesenteric ischemia and gastrointestinal failure. We investigated the effects of different PEEP levels on mesenteric leukocyte-endothelial interactions. METHODS: Forty-four male Wistar rats were initially anesthetized (Pentobarbital I.P. 50mg/kg) and randomly assigned to one of the following groups: 1) NAIVE (only anesthesia; n=9), 2) PEEP 0 (PEEP of 0 cmH2O, n=13), 3) PEEP 5 (PEEP of 5 cmH2O, n=12), and 4) PEEP 10 (PEEP of 10 cmH2O, n=13). Positive end expiratory pressure groups were tracheostomized and mechanically ventilated with a tidal volume of 10 mL/kg, respiratory rate of 70 rpm, and inspired oxygen fraction of 1. Animals were maintained under isoflurane anesthesia. After two hours, laparotomy was performed, and leukocyte-endothelial interactions were evaluated by intravital microscopy. RESULTS: No significant changes were observed in mean arterial blood pressure among groups during the study. Tracheal peak pressure was smaller in PEEP 5 compared with PEEP 0 and PEEP 10 groups (11, 15, and 16 cmH2O, respectively; p<0.05). After two hours of MV, there were no differences among NAIVE, PEEP 0 and PEEP 5 groups in the number of rollers (118±9,127±14 and 147±26 cells/10minutes, respectively), adherent leukocytes (3±1,3±1 and 4±2 cells/100µm venule length, respectively), and migrated leukocytes (2±1,2±1 and 2±1 cells/5,000µm², respectively) at the mesentery. However, the PEEP 10 group exhibited an increase in the number of rolling, adherent and migrated leukocytes (188±15 cells / 10 min, 8±1 cells / 100 µm and 12±1 cells / 5,000 µm², respectively; p<0.05). CONCLUSIONS: High intrathoracic pressure was harmful to mesenteric microcirculation in the experimental model of rats with normal lungs and ...

Comparison of the effects of lactated Ringer solution with and without hydroxyethyl starch fluid resuscitation on gut edema during severe splanchnic ischemia

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 percent hydroxyethyl starch solution; group II (N = 7) received 36 mL·kg-1·h-1 lactated Ringer solution and 20 mL/kg 0.9 percent saline. A segment from the ileum was isolated to be perfused. A tonometric catheter was placed in a second gut segment. Superior mesenteric artery (Q SMA) 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.

Acid-base disarrangement and gastric intramucosal acidosis predict outcome from major trauma / Desarranjo ácido-base e acidose gástrica intramucosal predizem desfecho de trauma grave

INTRODUCTION: This prospective non-interventional study intended to assess the prognostic value of gastric intramucosal acidosis in patients with severe trauma admitted to a medical/surgical ICU. METHODS: Gastric tonometer catheters were introduced to measure air PCO2 level (Tonocap device) in forty consecutive critically ill trauma patients. Gastric intramucosal pH, air PCO2 gradient, lactate and acid-base parameters were measured at admission and at 6, 12 and 24 h thereafter. RESULTS: The median age, mean APACHE II and SOFA scores were higher in nonsurvivors than in survivors (p<0.05). There were significant differences in the PCO2 gradient between survivors and nonsurvivors at 12 and 24 hours (10±7 vs. 24±19 mmHg, 13±16 vs. 29±25 mmHg; p<0.05). Gastric intramucosal pH values were lower in nonsurvivors than in survivors, on admission and after 12 or 24 hours (p<0.05). Arterial pH and bicarbonate were lower, lactate concentration higher, and base excess more negative in nonsurvivors. Prediction of outcome (mortality and MODS) at 24 hours of ICU assessed by their ROC curves was similar (p=NS). At 24 hours, air PCO2 gradient > 18 mmHg carried a relative risk of 4.6 for death, slightly higher than a HCO3 <20 mEq/L (RR=4.29) or base excess of <-2 mmol/L (RR=3.65). CONCLUSION: Bicarbonate, base deficit, lactate, gastric intramucosal pH and PCO2 gradient discriminate survivors from nonsurvivors of major trauma. A critical air PCO2 gradient carried the greatest relative risk for death at 24 hours of ICU. Inadequate regional blood flow as detected by a critical PCO2 gradient seems to contribute to morbidity and mortality of severe trauma patients.

INTRODUÇÃO: O objetivo deste estudo prospectivo, não-intervencionista, foi avaliar o valor prognóstico da acidose gástrica intramucosal em pacientes com trauma grave admitidos numa UTI. MÉTODOS: Cateteres tonométricos gástricos foram introduzidos para medir o nível de PCO2 aéreo em 40 pacientes traumatizados. O pH gástrico intramucosal, o gradiente de PCO2 aéreo, o lactato e os parâmetros ácido-base foram medidos na admissão e 6, 12 e 24 h após a admissão. RESULTADOS: A idade mediana, o APACHE II e os escores SOFA médios foram maiores nos não-sobreviventes que nos sobreviventes (p<0.05). Não houve diferenças significativas para o gradiente de PCO2 entre sobreviventes e não-sobreviventes após 12 e 24 horas (10±7 vs. 24±19 mmHg, 13±16 vs. 29±25 mmHg; P<0.05). Os valores de pH gástrico intramucosal foram menores nos não-sobreviventes que nos sobreviventes na admissão e após 12 ou 24 horas (P<0.05). O pH arterial e o bicarbonato foram menores, a concentração de lactato maior, o excesso de base mais negativo nos não-sobreviventes. Predição do desfecho (mortalidade e FMOS) nas 24 horas de UTI acessada pelas curvas ROC foi similar (p=NS). Nas 24 horas, um gradiente de PCO2 aéreo >18 mmHg acarretou um risco relativo de 4.6 para óbito, um pouco maior que um HCO3 <20 mEq/L (RR=4.29) ou um excesso de base <-2 mmol/L (RR=3.65). CONCLUSÃO: Bicarbonato, déficit de base, lactato, pH gástrico intramucosal e o gradiente de PCO2 discriminaram os sobreviventes dos não-sobreviventes de trauma. Um gradiente crítico de PCO2 aéreo acarretou o maior risco relativo para óbito após 24 horas de UTI. Fluxo sangüíneo regional inadequado detectado por um gradiente crítico de PCO2 parece contribuir para a morbidade e mortalidade de pacientes traumatizados graves.

Low hematocrit impairs gastric mucosal CO2 removal during experimental severe normovolemic hemodilution

OBJECTIVE: The net effects of acute normovolemic hemodilution with different hemoglobin levels on splanchnic perfusion have not been elucidated. The hypothesis that during moderate and severe normovolemic hemodilution, systemic and splanchnic hemodynamic parameters, oxygen-derived variables, and biochemical markers of anaerobic metabolism do not reflect the adequacy of gastric mucosa, was tested in this study. METHODS: Twenty one anesthetized mongrel dogs (16 ± 1 kg) were randomized to controls (CT, n = 7, no hemodilution), moderate hemodilution (hematocrit 2 5 percent ± 3 percent, n = 7) or severe hemodilution (severe hemodilution, hematocrit 15 percent ± 3 percent, n = 7), through an isovolemic exchange of whole blood and 6 percent hydroxyethyl starch, at a 20 mL/min rate, to the target hematocrit. The animals were followed for 120 min after hemodilution. Cardiac output (CO, L/min), portal vein blood flow (PVF, mL/min), portal vein-arterial and gastric mucosa-arterial CO2 gradients (PV-artCO2 and PCO2 gap, mm Hg, respectively) were measured throughout the experiment. RESULTS: Exchange blood volumes were 33.9 ± 3.3 and 61.5 ± 5.8 mL/kg for moderate hemodilution and severe hemodilution, respectively. Arterial pressure and systemic and regional lactate levels remained stable in all groups. There were initial increases in cardiac output and portal vein blood flow in both moderate hemodilution and severe hemodilution; systemic and regional oxygen consumption remained stable largely due to increases in oxygen extraction rate. There was a significant increase in the PCO2-gap value only in severe hemodilution animals. CONCLUSION: Global and regional hemodynamic stability were maintained after moderate and severe hemodilution. However, a very low hematocrit induced gastric mucosal acidosis, suggesting that gastric mucosal CO2 monitoring may be useful during major surgery or following trauma.

OBJETIVO: Os efeitos da hemodiluição normovolêmica com diferentes níveis de hemoglobina na perfusão esplâncnica são pouco conhecidos. Testamos a hipótese que durante a hemodiluição moderada e acentuada, os parâmetros hemodinâmicos sistêmicos e regionais e as variáveis relacionadas ao metabolismo de oxigênio não refletem a adequação da perfusão da mucosa gástrica. MÉTODOS: Vinte e um cães anestesiados com fentanil e vecurônio (16±1 kg) foram randomizados como controles (CT, n=7, sem hemodiluição normovolêmica), hemodiluição normovolêmica moderada (Ht 25±3 por cento, n=7) ou hemodiluição normovolêmica acentuada (Ht 15±3 por cento, n=7), pela troca isovolêmica entre o sangue total e hidroxietil amido a 6 por cento, 20 mL/min até o hematócrito pré-estabelecido para cada grupo. Os animais foram acompanhados por 120 min após a hemodiluição normovolêmica. Durante todo o experimento foram medidos o débito cardíaco (CO, L/min), o fluxo de veia porta (PVF, mL/min), e os gradientes de CO2 veia porta-arterial e mucosa gástrica-arterial (PV-artCO2 and PCO2-gap, mmHg, respectivamente). RESULTADOS: O volume de sangue trocado foi de 33,9±3,3 mL/kg para hemodiluição normovolêmica moderada e de 61,5±5,8 mL/kg para a hemodiluição normovolêmica acentuada. A pressão arterial e os níveis de lactato sistêmico e regional permaneceram estáveis em todos os grupos. Houve aumentos iniciais de débito cardíaco e de fluxo de veia porta, tanto na hemodiluição normovolêmica moderada quanto na hemodiluição normovolêmica acentuada; o consumo de oxigênio sistêmico e regional permaneceram estáveis, principalmente por conta de aumentos na taxa de extração de oxigênio. O PCO2-gap apresentou aumento significativo apenas nos animais submetidos a hemodiluição normovolêmica acentuada. CONCLUSÃO: Ocorre estabilidade hemodinâmica global e regional tanto na hemodiluição normovolêmica moderada quanto na acentuada. Entretanto, o hematócrito de 15 por cento induziu acidose moderada de mucosa gástrica, o que pode ser relevante em procedimentos cirúrgicos de grande porte ou no trauma.

Efeitos iniciais da reposição volêmica com solução salina hipertônica a 7.5 por cento na perfusão e oxigenação esplâncnica após choque hemorrágico / Early effects of 7.5 percent hypertonic saline solution on splanchnic perfusion after hemorrhagic shock

OBJETIVO: Avaliar os efeitos hemodinâmicos sistêmicos e esplâncnico da expansão volêmica inicial com SSH em modelo de choque hemorrágico controlado. MÉTODOS: Dez cães foram submetidos a sangramento controlado (20 ml/min) até uma pressão arterial média de 40±5 mmHg (PAM). Após 30 minutos de choque, receberam 4 ml/Kg de SSH em 5 minutos e posteriormente observados sem intervenções adicionais durante 60 minutos. As variáveis hemodinâmicas sistêmicas foram obtidas de um cateter arterial e de um cateter de Swan-Ganz, enquanto as regionais através da cateterização da veia porta, fluxômetro ultrassônico na veia porta e um tonômetro na cavidade. A oferta, taxa de extração e consumo esplâncnico de oxigênio, pH intramucoso e os gradientes veno-arterial, porta-arterial e mucosa-arterial da pCO2 (Dap-a pCO2, Dvp-a pCO2 e Dt-a pCO2, respectivamente), foram calculados. RESULTADOS: A hemorragia (29,8±2,4 ml/Kg) reduziu a pressão arterial média (125±6 para 42±1 mmHg), o DC (1,9±0,2 para 0,6±0,1 L/min) e o fluxo porta (504±73 para 126±12 ml/min), enquanto elevou o Dap-a pCO2 (5,3±0,8 para 19,9±1,6 mmHg), Dvp-a pCO2 (5,4±1,4 para 22,6±2,1 mmHg) e o Dt-a pCO2 (6,1±1,1 para 43,8±7,5 mmHg). A infusão de SSH resultou em recuperação parcial dos fluxos sistêmico e porta. Atenuou os gradientes de CO2 com menor impacto sobre o Dt-a pCO2. CONCLUSÃO: A SSH promoveu benefícios parciais na perfusão sistêmica e esplâncnica, os quais foram especialmente limitados na microcirculação regional, como demonstrado pelo Dt-a pCO2. Além disso, as variáveis sistêmicas e regionais dependentes de oxigênio, não refletem a adequação da perfusão da mucosa gástrica, enfatizando a importância da monitorização deste território - pela tonometria - durante os estados de choque.

Avaliação inicial dos gradientes sistêmicos e regionais da pCO2 como marcadores de hipoperfusão mesentérica / Initial evaluation of systemic and regional pCO2 gradients as markers of mesenteric hypoperfusion

RACIONAL: Apesar dos recentes avanços nos métodos de imagem e no cuidado dos doentes críticos, a taxa de mortalidade do abdome agudo vascular nas últimas duas décadas continua praticamente inalterada. OBJETIVOS: Avaliar as alterações imediatas dos gradientes regionais da pCO2 induzidas pela isquemia e reperfusão mesentérica. Determinar se outros marcadores sistêmicos de hipoperfusão esplâncnica são capazes de detectar precocemente as alterações circulatórias ocorridas na mucosa intestinal após oclusão da artéria mesentérica superior. MÉTODOS: Foram utilizados sete cães machos sem raça definida (20,6 ± 1,1 kg), submetidos a oclusão da artéria mesentérica superior por 45 minutos, sendo os animais observados por período adicional de 2 horas após a reperfusão. Variáveis hemodinâmicas sistêmicas foram avaliadas por meio de cateter arterial e Swan-Ganz. A perfusão do sistema digestório foi avaliada pela medida do fluxo sangüíneo da veia mesentérica superior e da serosa jejunal (fluxômetro ultra-sônico). Oferta, taxa de extração e consumo intestinal de oxigênio (DO2intest, TEO2intest e VO2intest, respectivamente), pH intramucoso (tonometria a gás) e os gradientes veia mesentérica-arterial e mucosa-arterial da pCO2 (Dvm-a pCO2 e Dt-a pCO2, respectivamente), foram calculados. RESULTADOS: A oclusão da artéria mesentérica superior não esteve associada a alterações hemodinâmicas sistêmicas, mas pôde-se observar aumento significativo do Dvm-a pCO2 (1,7 ± 0,5 para 5,7 ± 1,8 mm Hg) e do Dt-a pCO2 (8,2 ± 4,8 para 48,7 ± 4,6 mm Hg). Na fase de reperfusão observou-se redução da DO2intest (67,7 ± 9,9 para 38,8 ± 5,3 mL/min) e conseqüente aumento da TEO2intest de 5,0 ± 1,1 por cento para 12,4 ± 2,7 por cento. Não houve correlação entre os gradientes da pCO2 analisados. CONCLUSAO: A tonometria permite detectar de maneira precoce a redução de fluxo intestinal. Além disso, pudemos demonstrar que as variações dos gradientes regionais e/ou sistêmicos da pCO2 não são capazes de avaliar a magnitude da redução de fluxo da mucosa intestinal durante o fenômeno de isquemia e reperfusão mesentérica.

Evaluación de la enfermedad aterosclerótica celíaco-mesentérica en pacientes diabéticos con técnicas de imagen no invasivas / Evaluation of the disease aterosclerótica celíaco-mesentérica in diabetic patients with not invasive technologies(skills) of image

La circulación esplácnica es un lecho vascular con dos principales fuentes de flujo arterial, el Tronco Celíaco y la Arteria Mesentérica Superior. Existen múltiples comunicaciones entre ambas y con la Arteria Mesentérica Inferior. Debido a que existe este rico aporte arterial, la estenosis y aún la oclusión de alguno de estos tres vasos puede ocurrir sin síntomas abdominales isquémicos manifestos. La principal causa de estenosis es de origen arterioesclerótico y ocurre con mayor frecuencia en el origen de estos vasos, siendo responsable de más de 95 por ciento de los casos de isquemia mesentérica. En pacientes con sospecha de enfermedad vascular arteriosclerótica el método de imagen históricamente utilizado fue la arteriografía, que implica exposición a radiaciones ionizante y medios de contraste iodados nefrotóxicos. El objetivo de este trabajo fue demostrar que se pueden utilizar, en un grupo de pacientes vulnerables como los diabéticos, técnicas de imagen no invasivas como el Ultrasonido Doppler y la Angiografía por Resonancia Magnética en la deteccion de estenosis en el Tronco Celíaco y Arteria Mesentérica Superior, y establecer la relacion de sexo, edad, factores de riesgo y enfermedad vascular concomitante con la enfermedad aterosclerótica y de los vaos esplácnicos.

Management of visceral artery aneurysms

Objective: Visceral artery aneurysms, despite being uncommon, are important vascular diseases, since they frequently are life threatening, and often fatal emergencies. The purpose of this study is to review our experience with treatment of visceral artery aneurysms. Method: Between 1988 and June, 2004, 37 visceral artery aneurysms were treated in 35 patients (17 male and 18 female) with average age of 56 mais ou menos 14 years. The most common locations were the splenic artery (18), the hepatic artery (10) and the superior mesenteric artery (four), 22 patients were asymptomatic, 13 patients were symptomatic. Emergency surgery was performed on three patients, elective open surgery on 20 patients, and endovascular treatment onseven patients. Results: Perioperative mortality rate was 3,1 por cento in the surgical group. The perioperative mobidity rate was 5,7 por cento: one case of respiratory distress and one case of bilious fistula were...