Abstract The present study aims to verify the effect of ozone gas (OZY® System) and high frequency electric pulse (Endox® System) systems on human root canals previously contaminated with Escherichia colilipopolysaccharide (LPS). Fifty single-rooted teeth had their dental crowns removed and root lengths standardized to 16 mm. The root canals were prepared up to #60 hand K-files and sterilized using gamma radiation with cobalt 60. The specimens were divided into the following five groups (n = 10) based on the disinfection protocol used: OZY® System, one 120-second-pulse (OZY 1p); OZY® System, four 24-second-pulses (OZY 4p); and Endox® System (ENDOX). Contaminated and non-contaminated canals were exposed only to apyrogenic water and used as positive (C+) and negative (C-) controls, respectively. LPS (O55:B55) was administered in all root canals except those belonging to group C-. After performing disinfection, LPS samples were collected from the canals using apyrogenic paper tips. Limulus Amoebocyte Lysate (LAL) was used to quantify the LPS levels, and the data obtained was analyzed using one-way ANOVA. The disinfection protocols used were unable to reduce the LPS levels significantly (p = 0.019). The use of ozone gas and high frequency electric pulses was not effective in eliminating LPS from the root canals.
OBJECTIVES: This study tests the hypothesis that local or remote ischemic preconditioning may protect the intestinal mucosa against ischemia and reperfusion injuries resulting from temporary supraceliac aortic clamping. METHODS: Twenty-eight Wistar rats were divided into four groups: the sham surgery group, the supraceliac aortic occlusion group, the local ischemic preconditioning prior to supraceliac aortic occlusion group, and the remote ischemic preconditioning prior to supraceliac aortic occlusion group. Tissue samples from the small bowel were used for quantitative morphometric analysis of mucosal injury, and blood samples were collected for laboratory analyses. RESULTS: Supraceliac aortic occlusion decreased intestinal mucosal length by reducing villous height and elevated serum lactic dehydrogenase and lactate levels. Both local and remote ischemic preconditioning mitigated these histopathological and laboratory changes. CONCLUSIONS: Both local and remote ischemic preconditioning protect intestinal mucosa against ischemia and reperfusion injury following supraceliac aortic clamping.
OBJECTIVES: The anesthetic gas xenon is reported to preserve hemodynamic stability during general anesthesia. However, the effects of the gas during shock are unclear. The objective of this study was to evaluate the effect of Xe on hemodynamic stability and tissue perfusion in a canine model of hemorrhagic shock. METHOD: Twenty-six dogs, mechanically ventilated with a fraction of inspired oxygen of 21% and anesthetized with etomidate and vecuronium, were randomized into Xenon (Xe; n = 13) or Control (C; n = 13) groups. Following hemodynamic monitoring, a pressure-driven shock was induced to reach an arterial pressure of 40 mmHg. Hemodynamic data and blood samples were collected prior to bleeding, immediately after bleeding and 5, 20 and 40 minutes following shock. The Xe group was treated with 79% Xe diluted in ambient air, inhaled for 20 minutes after shock. RESULT: The mean bleeding volume was 44 mL.kg-1 in the C group and 40 mL.kg-1 in the Xe group. Hemorrhage promoted a decrease in both the cardiac index (p<0.001) and mean arterial pressure (p<0.001). These changes were associated with an increase in lactate levels and worsening of oxygen transport variables in both groups (p<0.05). Inhalation of xenon did not cause further worsening of hemodynamics or tissue perfusion markers. CONCLUSIONS: Xenon did not alter hemodynamic stability or tissue perfusion in an experimentally controlled hemorrhagic shock model. However, further studies are necessary to validate this drug in other contexts.
BACKGROUND: In spite of the fact that the number of surgeries presented by the elective surgery task force did not entirely reflect the reality, it is possible to declare that the financial implementation of the Brazilian Ministry of Health has been significative, as well as the increasing number of varicose vein surgeries, especially after the creation of the Strategic Actions and Compensation Fund (FAEC). OBJECTIVE: To evaluate the application of financial investment in the Ministry of Health campaign for varicose vein surgery. METHODS: A transversal study of retrospective nature has been conducted, using information available at the Data Processing Department of the National Healthcare System database (DATASUS). All the authorization of hospital internment from the inferior member varicose vein surgeries, financed by the Brazilian Ministry of Health from January 1998 to December 2004, have been included in the research. RESULTS: In 1998, before the implementation of the elective surgery task force, 23,531 varicose vein surgeries have been performed, and R$ 5,819,033.27 invested. After the creation of the FAEC, 457,026 inferior member varicose vein surgeries have been performed from 1999 to 2004, and R$ 187,760,196.81 were invested with an average of R$ 31,293,336.13 per year. CONCLUSION: Thus, it is possible to conclude that the bigger investment from the Brazilian Ministry of Health, represented by the implementation of the elective surgery task forces by the FAEC, has been responsible for increasing the number of varicose vein surgeries all around Brazil.
CONTEXTO: Apesar de reconhecer que o número apresentado pelo mutirão de cirurgias eletivas não refletisse inteiramente a realidade, foi significativa a implementação financeira do Ministério da Saúde do Brasil, bem como o aumento de cirurgias de varizes, após criação do Fundo de Ações Estratégias e Compensação (FAEC). OBJETIVO: Avaliar os resultados da aplicação do investimento financeiro do Ministério da Saúde no mutirão de cirurgias de varizes. MÉTODOS:Foi realizado um estudo transversal de natureza retrospectiva, utilizando informações do banco de dados do Departamento de Informática do Sistema Único de Saúde. Foram incluídas na pesquisa todas autorizações de internação hospitalar das cirurgias de varizes de membros inferiores pagas pelo Ministério da Saúde do Brasil, no período de janeiro de 1998 a dezembro de 2004. RESULTADOS: Em 1998, antes da implementação do mutirão de cirurgias eletivas foram realizadas 23.531 cirurgias de varizes e investidos R$ 5.819.033,27. Após a criação do FAEC, foram realizadas 457.026 cirurgias de varizes de membros inferiores, no período de 1999 a 2004, e foram investidos R$ 187.760.196,81 com média de R$ 31.293.336,13 por ano. CONCLUSÃO: O investimento feito pelo Ministério da Saúde durante o programa de mutirões de cirurgias eletivas pelo FAEC, proporcionou aumento significativo do número de cirurgias de varizes em todo Brasil.
BACKGROUND: Trauma and thrombosis that can result in changes in the venous drainage of the upper limb, depending on the vascular territory interrupted, may have as a compensatory mechanism a collateral drainage channel that prevents damage to the venous return of that limb. The common brachial vein is a plausible and little known collateral channel for this purpose. OBJECTIVE: To describe the anatomy of the common brachial vein as a collateral drainage channel of the upper limb. METHODS: We have dissected 30 cadavers of people of different races, whose upper limbs were articulated to the trunk and preserved in a 10% formaldehyde solution. The exclusion criteria were disarticulated limbs or deformities in the topography of the studied structures. RESULTS: The common brachial vein was present in 73% (22/30) of the cadavers dissected. The common brachial vein drained into the axillary vein in 82% (18/22) and into the basilic vein in the proximal segment of the upper limb in 18% of the cadavers (04/22). CONCLUSION: The common brachial vein is frequently present, and, in most cases, it drains into the axillary vein.
CONTEXTO: Traumatismos ou tromboses que possam evoluir com alterações da drenagem venosa do membro superior, dependendo do território interrompido, podem ter como mecanismo compensatório uma via colateral de drenagem sem que haja prejuízo para o retorno venoso desse membro. A veia braquial comum apresenta-se como uma alternativa plausível e pouco conhecida. OBJETIVO: Descrever a anatomia da veia braquial comum como via de drenagem colateral no membro superior. MÉTODOS: Utilizamos 30 cadáveres do sexo masculino, cujos membros superiores estavam articulados ao tronco, não importando a raça, formolizados e mantidos em conservação com solução de formol a 10%. Utilizamos como critérios de exclusão cadáveres com um dos membros desarticulado ou alterações deformantes em topografia das estruturas estudadas. RESULTADOS: A veia braquial comum esteve presente em 73% (22/30) dos cadáveres estudados, sendo que em 18% (04/22) dos casos drenou para a veia basílica no seguimento proximal do braço e em 82% (18/22), para a veia axilar. CONCLUSÃO: A veia braquial comum está frequentemente presente e, na maior parte das vezes, desemboca na veia axilar.
OBJECTIVE: To examine the severity of trauma in entrapped victims and to identify risk factors for mortality and morbidity. INTRODUCTION: Triage and rapid assessment of trauma severity is essential to provide the needed resources during prehospital and hospital phases and for outcome prediction. It is expected that entrapped victims will have greater severity of trauma and mortality than non-entrapped subjects. METHODS: A transverse, case-control, retrospective study of 1203 victims of motor vehicle collisions treated during 1 year by the prehospital service in São Paulo, Brazil was carried out. All patients were drivers, comprising 401 entrapped victims (33.3%) and 802 non-entrapped consecutive controls (66.7%). Sex, age, mortality rates, Glasgow Coma Scale (GCS), Revised Trauma Score (RTS), corporal segments, timing of the prehospital care and resource use were compared between the groups. The results were analysed by χ2, Zres, analysis of variance and Bonferroni tests. RESULTS: Entrapped victims were predominantly men (84.8%), aged 32±13.1 years, with immediate mortality of 10.2% and overall mortality of 11.7%. They had a probability of death at the scene 8.2 times greater than that of non-entrapped victims. The main cause of death was hemorrhage for entrapped victims (45.2%) and trauma for non-entrapped victims. Of the entrapped victims who survived, 18.7% had a severe GCS (OR = 10.62), 12% a severe RTS (OR = 9.78) and 23.7% were in shock (OR = 3.38). Entrapped victims were more commonly transported to advanced life support units and to tertiary hospitals. CONCLUSION: Entrapped victims had greater trauma severity, more blood loss and a greater mortality than respective, non-entrapped controls.
OBJECTIVE: To evaluate the feasibility of using endovascular repair to treat penetrating arterial injuries with covered stents. Feasibility was examined according to the circumferential extent of the injury. INTRODUCTION: Surgical trauma often increases the risk of major morbidity and mortality associated with vascular injury, and endovascular repair has many advantages in such situations. METHODS: Twenty white male domestic pigs weighing 28-38 kg with controlled vascular injuries were divided into four equal groups according to the circumferential extent of their vascular lesion (i.e., no lesion, lesion <50%, lesion >50%, and complete lesion). The left common carotid artery was dissected with proximal and distal control, and this procedure was followed by controlled sectioning of the arterial wall. Local manual compression was applied for 10 min and was followed by endovascular repair with the placement of a 5x50 mm VIABHAN TM covered stent using the femoral approach. We also monitored additional variables, such as the duration of the procedures (the mean was 56.3 ± 19.1 min), ultrasound parameters (e.g., maximum arterial diameter, peak systolic and diastolic velocity, and resistance index), arteriography findings, and fluctuations in vital signs (e.g., cardiac output, arterial pressure, and central venous pressure). RESULTS: The experimental procedure was found to be feasible and reproducible. Repairs were successful in all animals in the control (no lesion) and <50% lesion groups. Success was also achieved in four out of five pigs in the >50% group and in one pig in the complete lesion group. DISCUSSION: The endovascular repair of an arterial injury is possible, but success depends on the circumferential extent of the arterial lesion. The present experimental model, which involved endovascular techniques, highlighted important factors that must be considered in future studies involving similar animals and materials.
This study aimed to present the general principles for experiments performed on laboratory animals as required by international and national ethical committees on animal welfare. Compliance to these principles is a prerequisite for publication in international journals. Details of genetic, sanitary and environmental standards, transportation, acclimation, environmental enrichment, appropriate education and training of all those involved in handling of live animals, information management strategy, biossecurity, diet, anesthesia, analgesia, postoperative care and euthanasia for Mus musculus (mice), Rattus norvegicus (rat), Oryctolagus cuniculus (rabbit) and Sus scropha domesticus (pig) combined with well planned biomedical research are fundamental to increase the accuracy, reproducibility and precision of the experimental results.
Com o objetivo de contribuir à pesquisa em cirurgia experimental, este artigo apresenta uma análise dos principais parâmetros exigidos a serem observados pelos comitês internacionais e nacionais de ética e bem-estar animal, cujo cumprimento é pré-requisito para publicação em periódicos arbitrados de circulação internacional. A padronização da genética, do estado sanitário e do ambiente das espécies de animais Mus musculus (camundongos), Rattus norvegicus (ratos), Oryctolagus cuniculus (coelhos) e Sus scropha domesticus (suínos), a observação de condições adequadas no transporte, aclimatação, enriquecimento do ambiente, treinamento de técnicos em experimentação animal, gestão de informação, biossegurança, dieta, anestesia, cuidados pós-operatórios, analgesia e eutanásia, aliados a projetos de pesquisa bem planejados são apresentados como etapas fundamentais para a obtenção de resultados com alto grau de acuidade, alto nível de reprodutibilidade e precisão.
OBJECTIVE: To test the hypothesis that pulse pressure respiratory variation (PPV) amplification, observed in hypovolemia, can also be observed during sodium nitroprusside (SNP)-induced vasodilation. INTRODUCTION: PPV is largely used for early identification of cardiac responsiveness, especially when hypovolemia is suspected. PPV results from respiratory variation in transpulmonary blood flow and reflects the left ventricular preload variations during respiratory cycles. Any factor that decreases left ventricular preload can be associated with PPV amplification, as seen in hypovolemia. METHODS: Ten anesthetized and mechanically ventilated rabbits underwent progressive hypotension by either controlled hemorrhage (Group 1) or intravenous SNP infusion (Group 2). Animals in Group 1 (n = 5) had graded hemorrhage induced at 10% steps until 50% of the total volume was bled. Mean arterial pressure (MAP) steps were registered and assumed as pressure targets to be reached in Group 2. Group 2 (n = 5) was subjected to a progressive SNP infusion to reach similar pressure targets as those defined in Group 1. Heart rate (HR), systolic pressure variation (SPV) and PPV were measured at each MAP step, and the values were compared between the groups. RESULTS: SPV and PPV were similar between the experimental models in all steps (p > 0.16). SPV increased earlier in Group 2. CONCLUSION: Both pharmacologic vasodilation and graded hemorrhage induced PPV amplification similar to that observed in hypovolemia, reinforcing the idea that amplified arterial pressure variation does not necessarily represent hypovolemic status but rather potential cardiovascular responsiveness to fluid infusion.
PRUPOSE: Bacterial translocation has been shown to occur in critically ill patients after extensive trauma, shock, sepsis, or thermal injury. The present study investigates mesenteric microcirculatory dysfunctions, the bacterial translocation phenomenon, and hemodynamic/metabolic disturbances in a rat model of intestinal obstruction and ischemia. METHODS: Anesthetized (pentobarbital 50 mg/kg, i.p.) male Wistar rats (250-350 g) were submitted to intestinal obstruction or laparotomy without intestinal obstruction (Sham) and were evaluated 24 hours later. Bacterial translocation was assessed by bacterial culture of the mesenteric lymph nodes (MLN), liver, spleen, and blood. Leukocyte-endothelial interactions in the mesenteric microcirculation were assessed by intravital microscopy, and P-selectin and intercellular adhesion molecule (ICAM)-1 expressions were quantified by immunohistochemistry. Hematocrit, blood gases, lactate, glucose, white blood cells, serum urea, creatinine, bilirubin, and hepatic enzymes were measured. RESULTS: About 86% of intestinal obstruction rats presented positive cultures for E. coli in samples of the mesenteric lymph nodes, liver, and spleen, and 57% had positive hemocultures. In comparison to the Sham rats, intestinal obstruction induced neutrophilia and increased the number of rolling (~2-fold), adherent (~5-fold), and migrated leukocytes (~11-fold); this increase was accompanied by an increased expression of P-selectin (~2-fold) and intercellular adhesion molecule-1 (~2-fold) in the mesenteric microcirculation. Intestinal obstruction rats exhibited decreased PaCO2, alkalosis, hyperlactatemia, and hyperglycemia, and increased blood potassium, hepatic enzyme activity, serum urea, creatinine, and bilirubin. A high mortality rate was observed after intestinal obstruction (83% at 72 h vs. 0% in Sham rats). CONCLUSION: Intestinal obstruction and ischemia in rats is a relevant model for the in vivo study of mesenteric microcirculatory dysfunction and the occurrence of bacterial translocation. This model parallels the events implicated in multiple organ dysfunction (MOD) and death.
Sepsis is a syndrome related to severe infections. It is defined as the systemic host response to microorganisms in previously sterile tissues and is characterized by end-organ dysfunction away from the primary site of infection. The normal host response to infection is complex and aims to identify and control pathogen invasion, as well as to start immediate tissue repair. Both the cellular and humoral immune systems are activated, giving rise to both anti-inflammatory and proinflammatory responses. The chain of events that leads to sepsis is derived from the exacerbation of these mechanisms, promoting massive liberation of mediators and the progression of multiple organ dysfunction. Despite increasing knowledge about the pathophysiological pathways and processes involved in sepsis, morbidity and mortality remain unacceptably high. A large number of immunomodulatory agents have been studied in experimental and clinical settings in an attempt to find an efficacious anti-inflammatory drug that reduces mortality. Even though preclinical results had been promising, the vast majority of these trials actually showed little success in reducing the overwhelmingly high mortality rate of septic shock patients as compared with that of other critically ill intensive care unit patients. Clinical management usually begins with prompt recognition, determination of the probable infection site, early administration of antibiotics, and resuscitation protocols based on "early-goal" directed therapy. In this review, we address the research efforts that have been targeting risk factor identification, including genetics, pathophysiological mechanisms and strategies to recognize and treat these patients as early as possible.
BACKGROUND: A great part of venous insufficiencies is due to valve incompetence. Valved venous grafts in the insufficient segment are a surgical alternative. OBJECTIVE: To describe the anatomy of the common brachial vein valves. METHODS: We used 30 male corpses of varied races with their upper limbs articulated to the trunk. They were preserved in formol and fixed in a 10% formol solution. Exclusion criteria were presence of disarticulation in one limb or deforming alterations in the topography of assessed structures. RESULTS: The total number of identified valves was 28 in the right arm and 33 in the left arm, 15 of them in the right proximal segment and 21 in the left proximal segment. More than 91% of the valves were bicuspid and parietal. CONCLUSION: We conclude that the common brachial vein often presents bicuspid and parietal valves.
CONTEXTO: Boa parte das insuficiências venosas é devida à incompetência de suas válvulas. Como uma das alternativas cirúrgicas, temos os enxertos venosos valvulados no segmento insuficiente. OBJETIVO: Descrever a anatomia das válvulas da veia braquial comum. MÉTODOS: Foram selecionados 30 cadáveres do sexo masculino, independentemente de raça, que tinham seus membros superiores articulados ao tronco. Os mesmos estavam formolizados e foram mantidos em conservação com solução de formol a 10%. Utilizamos como critério de exclusão a existência de desarticulação de um dos membros ou de alterações deformantes em topografia das estruturas estudadas. RESULTADOS: O número total de válvulas identificadas foi de 28 em membro superior direito e de 33 em membro superior esquerdo, sendo 15 no segmento proximal direito e 21 no segmento proximal esquerdo. Mais de 91% das válvulas foram do tipo bicúspide e parietal. CONCLUSÃO: Conclui-se que a veia braquial comum apresenta freqüentemente válvulas do tipo bicúspide e parietal.
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% ± 3%, n = 7) or severe hemodilution (severe hemodilution, hematocrit 15% ± 3%, n = 7), through an isovolemic exchange of whole blood and 6% 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%, n=7) ou hemodiluição normovolêmica acentuada (Ht 15±3%, n=7), pela troca isovolêmica entre o sangue total e hidroxietil amido a 6%, 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% induziu acidose moderada de mucosa gástrica, o que pode ser relevante em procedimentos cirúrgicos de grande porte ou no trauma.
PURPOSE: To evaluate the effects of SSH resuscitation on systemic and splanchnic hemodynamic variables in an experimental model of controlled hemorrhagic shock. METHODS: Ten mongrel dogs were bled (20 ml/min) to a target mean arterial pressure (MAP) of 40±5 mmHg. After 30 minutes of shock, animals received SSH infused in 5-minute and they were observed for 60 minutes thereafter. Systemic hemodynamics were evaluated through a Swan-Ganz and arterial catheters while gastrointestinal tract perfusion by a catheter inside the portal vein, an ultrasonic flowprobe around portal vein blood flow (PVBF) and a gastric tonometer. Splanchnic oxygen delivery and consumption, intramucosal pH and veno-arterial, portal-arterial and mucosal-arterial pCO2-gradients (Dap-a pCO2, Dvp-a pCO2 e Dt-a pCO2, respectively) were assessed. RESULTS: Hemorrhage (29.8±2.4ml/Kg) induced significant decreases in MAP (125±6 to 42±1 mmHg), in CO (1.9±0.2 to 0.6±0.1 L/min), and PVBF (504±73 to 126±12 ml/min) while significant increases were detected in Dap-a pCO2 (5.3±0.8 to 19.9±1.6 mmHg) Dvp-a pCO2 (5.4±1.4 to 22.6±2.1 mmHg) and Dt-a pCO2 (6.1±1.1 to 43.8±7.5 mmHg). SSH infusion promoted only partial benefits in systemic and splanchnic blood flows. Reduced pCO2 gradients but fewer effects in Dt-a pCO2 were observed. CONCLUSION: The SSH infusion promoted partial systemic and splanchnic hemodynamic benefits. Those benefits were especially poor at the splanchnic microcirculation, as evaluated by Dt-a pCO2. In addition, systemic and regional oxygen-derived variables do not reflect the regional microcirculation disturbances. Gastrointestinal tonometry clearly represents a useful tool for monitoring splanchnic perfusion in patients in hemodynamic 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.