Efeitos hemodinâmicos e metabólicos iniciais da evisceração abdominal total para transplante multivisceral experimental

PURPOSE: Multivisceral transplantation (MVTx) has been accepted as standard therapeutic modality for patients with short-bowel syndrome associated with irreversible liver failure. Even nowadays, experimental models of MVTx grounds high incidence of intraoperative or early recipient mortality. Despite the known deleterious effects of hepatosplanchnic exenteration the impact of this procedure on systemic hemodynamics and metabolism remains to be determined. METHODS: Nine dogs (20.1±0.5 kg) were subjected to an en bloc resection of all abdominal organs including, stomach, duodenum, pancreas, liver, spleen, small bowel, and colon. A woven double velour vascular graft was interposed between the suprahepatic and infrahepatic vena cava. Systemic hemodynamic were evaluated through a Swan-Ganz catheter, ultrasonic flowprobes, and arterial lines. Systemic O2-derived variables, glucose, and lactate metabolism were analyzed throughout the experiment. RESULTS: Complete abdominal exenteration was associated with significant reduction in cardiac output, and mean arterial pressure (57% and 14%, respectively). Two hours after reperfusion a significant reduction in arterial pH and glucose were also observed. Oxygen consumption remained unaltered during the first two hours of the experiment, with a significant increase of lactate levels (1.4±0.3 vs. 7.6±0.4, p<0.05). Three animals died before the 3 hours of reperfusion were completed. Total abdominal exenteration for MVTx in dogs is associated with early major hemodynamics, and metabolic changes. CONCLUSION: The deleterious hemodynamic alterations observed are probably related with the association of severe acidosis, hyperlactemia, hypoglycemia, and reduction of total circulating blood volume. Close hemodynamic and metabolic monitoring should be provided during experimental MVTx in order to promote an increase in successful rates of this complex and challenging procedure.OBJETIVO: O transplante multivisceral (MVTx) é preconizado como tratamento de escolha em pacientes com síndrome do intestine curto associado com falência hepática irreverssível. Modelos experimentais de MVTx apresentam altas taxas de mortalidade intra-operatória e nas primeiras horas apos a reperfusão. Apesar dos deletérios efeitos hemodinâmicos da exenteração abdominal, o impacto deste procedimento na perfusão e no metabolismo sistêmico ainda esta por ser determinado. MÉTODOS: Nove cães (20.1±0.5 kg) foram submetidos a ressecção em bloco de todos os orgãos abdominais incluindo, estômago, duodeno, pancreas, fígado, baço, intestino delgado, e colon. Uma prótese vascular foi interposta entre a veia cava infra e supra-hepática. Efeitos hemodinâmicos foram avaliados por meio de um cateter de Swan-Ganz catheter e Doppler ultrassônico. As variáveis dependentes de oxigênio, e o metabolismo da glicose e lactato foram avaliados durante todo o experimento. RESULTADOS: A evisceração abdominal esteve associada a uma redução significativa do débito cardiaco e da pressão arterial média (57% and 14%, respectivamente). Duas horas após a reconstrução vascular da veia cava inferior observou-se uma redução significativa do pH e da glicose arterial. O consumo de oxigênio se manteve inalterado nas primeiras duas horas do experimento, com um significativo aumento dos níveis séricos de lactato (1.4±0.3 vs. 7.6±0.4, p<0.05). Três animais morreram antes de 180 minutos após a reperfusão. CONCLUSÃO: A evisceração abdominal total esteve associada com graves repercussões hemodinâmicas e metabólicas sistêmicas. Estas graves alterações hemodinâmicas estam associadas, provavelmente, a combinação de vários fatores incluindo: acidose metabólica, hiperlactemia, hipoglicemia e redução do volume de sangue circulante. A cuidadosa monitorização hemodinâmica e metabólica deve ser realizada durante o MVTx experimental com a finalidade de promover um aumento das taxas de sobrevida deste complexo procedimento

Because scientists are unable to explain the unexplained, screening for cardiovascular abnormalities is a good method to protect against sudden unexpected death in patients with epilepsy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade Federal de São Paulo (UNIFESP) Departamento de FisiologiaUniversidade de São Paulo Faculdade de Medicina Hospital das ClínicasUNIFESP, EPMUNIFESP, Depto. de FisiologiaSciEL

Effects of volume resuscitation on splanchnic perfusion in canine model of severe sepsis induced by live Escherichia coli infusion

INTRODUCTION: We conducted the present study to investigate whether early large-volume crystalloid infusion can restore gut mucosal blood flow and mesenteric oxygen metabolism in severe sepsis. METHODS: Anesthetized and mechanically ventilated male mongrel dogs were challenged with intravenous injection of live Escherichia coli (6 × 10(9 )colony-forming units/ml per kg over 15 min). After 90 min they were randomly assigned to one of two groups – control (no fluids; n = 13) or lactated Ringer's solution (32 ml/kg per hour; n = 14) – and followed for 60 min. Cardiac index, mesenteric blood flow, mean arterial pressure, systemic and mesenteric oxygen-derived variables, blood lactate and gastric carbon dioxide tension (PCO(2); by gas tonometry) were assessed throughout the study. RESULTS: E. coli infusion significantly decreased arterial pressure, cardiac index, mesenteric blood flow, and systemic and mesenteric oxygen delivery, and increased arterial and portal lactate, intramucosal PCO(2), PCO(2 )gap (the difference between gastric mucosal and arterial PCO(2)), and systemic and mesenteric oxygen extraction ratio in both groups. The Ringer's solution group had significantly higher cardiac index and systemic oxygen delivery, and lower oxygen extraction ratio and PCO(2 )gap at 165 min as compared with control animals. However, infusion of lactated Ringer's solution was unable to restore the PCO(2 )gap. There were no significant differences between groups in mesenteric oxygen delivery, oxygen extraction ratio, or portal lactate at the end of study. CONCLUSION: Significant disturbances occur in the systemic and mesenteric beds during bacteremic severe sepsis. Although large-volume infusion of lactated Ringer's solution restored systemic hemodynamic parameters, it was unable to correct gut mucosal PCO(2 )gap

Promessa do ômega-3 contra a morte súbita em epilepsia: até segunda ordem, continua inocente, até que se prove o contrário

The present paper highlighted the importance of the recommended levels of fish consumption or omega-3 supplementation in order to minimize the frequency of seizures in people with uncontrolled epilepsy and, especially, to reduce the occurrence of sudden unexpected death in epilepsy (SUDEP).O presente trabalho destacou a importância dos níveis recomendados de consumo de peixe ou suplementação de ômega-3 com o intuito de minimizar a frequência de crises epilépticas em pessoas com epilepsia refratária e, especialmente, de reduzir a ocorrência de morte súbita inesperada em epilepsia (SUDEP).Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Departamento de MedicinaUniversidade Presbiteriana Mackenzie Programa de Pós-graduação em Distúrbios do DesenvolvimentoUniversidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Departamento de FisiologiaUniversidade de São Paulo Faculdade de Medicina Hospital das ClínicasUNIFESP, EPM, Depto. de MedicinaUNIFESP, EPM, Depto. de FisiologiaSciEL

Small volume of hypertonic saline as the initial fluid replacement in experimental hypodynamic sepsis

INTRODUCTION: We conducted the present study to examine the effects of hypertonic saline solution (7.5%) on cardiovascular function and splanchnic perfusion in experimental sepsis. METHODS: Anesthetized and mechanically ventilated mongrel dogs received an intravenous infusion of live Escherichia coli over 30 minutes. After 30 minutes, they were randomized to receive lactated Ringer's solution 32 ml/kg (LR; n = 7) over 30 minutes or 7.5% hypertonic saline solution 4 ml/kg (HS; n = 8) over 5 minutes. They were observed without additional interventions for 120 minutes. Cardiac output (CO), mean arterial pressure (MAP), portal and renal blood flow (PBF and RBF, respectively), gastric partial pressure of CO(2 )(pCO(2); gas tonometry), blood gases and lactate levels were assessed. RESULTS: E. coli infusion promoted significant reductions in CO, MAP, PBF and RBF (approximately 45%, 12%, 45% and 25%, respectively) accompanied by an increase in lactate levels and systemic and mesenteric oxygen extraction (sO(2)ER and mO(2)ER). Widening of venous-arterial (approximately 15 mmHg), portal-arterial (approximately 18 mmHg) and gastric mucosal-arterial (approximately 55 mmHg) pCO(2 )gradients were also observed. LR and HS infusion transiently improved systemic and regional blood flow. However, HS infusion was associated with a significant and sustained reduction of systemic (18 ± 2.6 versus 38 ± 5.9%) and mesenteric oxygen extraction (18.5 ± 1.9 versus 36.5 ± 5.4%), without worsening other perfusional markers. CONCLUSION: A large volume of LR or a small volume of HS promoted similar transient hemodynamic benefits in this sepsis model. However, a single bolus of HS did promote sustained reduction of systemic and mesenteric oxygen extraction, suggesting that hypertonic saline solution could be used as a salutary intervention during fluid resuscitation in septic patients

Blood Loss and Transcapillary Refill in Uncontrolled Treated Hemorrhage in Dogs

OBJETIVE: This study evaluated retroperitoneal hematomas produced by bilateral injury of iliac arteries (uncontrolled hemorrhage), blood volume loss, transcapillary refill, the effects of volume replacement on retroperitoneal bleeding and the hemodynamic changes with and without treatment. METHODS: Initial blood volume was determined with Tc99m-labelled red cells, and bleeding was evaluated by means of a portable scintillation camera positioned over the abdomen. Previously splenectomized mongrel dogs (16.8 ± 2.2 kg) were submitted to hemorrhage for 30 minutes and randomized into three groups: I - no treatment (n=7); II - treatment with 32 mL/kg of Lactated Ringer's for three to five minutes (n=7); and III - treatment with 4 mL/kg of 7.5% NaCl plus 6.0% dextran 70 for three to five minutes (n=7). They were studied for an additional 45 minutes. RESULTS: Volume replacement produced transitory recovery in hemodynamic variables, including mean pulmonary artery pressure, pulmonary capillary wedge pressure and cardiac index, with significant increase in dogs treated with 32 mL/kg of Lactated Ringer's and 7.5% NaCl plus 6.0% dextran 70 (p<0.001, against no treatment), along with a decrease (p<0.001) in the systemic vascular resistance index. Groups II and III had significant initial decreases in hematocrit and hemoglobin. The treated dogs (groups II and III) presented rebleeding, which was greater during treatment with 32 mL/kg of Lactated Ringer's (group II). CONCLUSIONS: Despite the rebleeding observed in treated groups, the utilization of hypertonic saline solution with dextran proved to be effective in the initial reanimation, producing evident transcapillary refill, while the Lactated Ringer's solution produced capillary extravasation and was ineffective in the initial volume replacement in this model of uncontrolled hemorrhage

Solução salina hipertônica aumenta a pressão de perfusão cerebral no transplante do fígado para hepatite fulminante: resultados preliminares

During orthotopic liver transplantation for fulminant hepatic failure, some patients may develop sudden deterioration of cerebral perfusion and oxygenation, mainly due to increased intracranial pressure and hypotension, which are likely responsible for postoperative neurological morbidity and mortality. In the present study, we hypothesized that the favorable effects of hypertonic saline solution (NaCl 7.5%, 4 mL/kg) infusion on both systemic and cerebral hemodynamics, demonstrated in laboratory and clinical settings of intracranial hypertension and hemorrhagic shock resuscitation, may attenuate the decrease in cerebral perfusion pressure that often occurs during orthotopic liver transplantation for fulminant hepatic failure. METHODS: 10 patients with fulminant hepatic failure in grade IV encephalopathy undergoing orthotopic liver transplantation with intracranial pressure monitoring were included in this study. The effect on cerebral and systemic hemodynamics in 3 patients who received hypertonic saline solution during anhepatic phase (HSS group) was examined, comparing their data with historical controls obtained from surgical procedure recordings in 7 patients (Control group). The maximal intracranial pressure and the corresponding mean arterial pressure values were collected in 4 time periods: (T1) the last 10 min of the dissection phase, (T2) the first 10 minutes at the beginning of anhepatic phase, (T3) at the end of the anhepatic phase, and (T4) the first 5 minutes after graft reperfusion. RESULTS: Immediately after hypertonic saline solution infusion, intracranial pressure decreased 50.4%. During the first 5 min of reperfusion, the intracranial pressure remained stable in the HSS group, and all these patients presented an intracranial pressure lower than 20 mm Hg, while in the Control group, the intracranial pressure increased 46.5% (P < 0.001). The HSS group was the most hemodynamically stable; the mean arterial pressure during the first 5 min of reperfusion increased 21.1% in the HSS group and decreased 11.1% in the Control group (P < 0.001). During the first 5 min of reperfusion, cerebral perfusion pressure increased 28.3% in the HSS group while in the Control group the cerebral perfusion pressure decreased 28.5% (P < 0.001). Serum sodium at the end of the anhepatic phase and 3 hours after reperfusion was significantly higher in the HSS group (153.00 &plusmn; 2.66 and 149.00 &plusmn; 1.73 mEq/L) than in the Control group (143.71 &plusmn; 3.30 and 142.43 &plusmn; 1.72 mEq/L), P = 0.003 and P < 0.001 respectively. CONCLUSION: Hypertonic saline solution can be successfully used as an adjunct in the neuroprotective strategy during orthotopic liver transplantation for fulminant hepatic failure, reducing intracranial pressure while restoring arterial blood pressure, promoting sustained increase in the cerebral perfusion pressure.Neste estudo testamos a hipótese de que os efeitos benéficos decorrentes da administração da solução salina hipertônica (NaCl 7,5%, 4 mL/kg) sobre a hemodinâmica sistêmica e cerebral na hipertensão intracraniana e no choque hemorrágico, possam atenuar a diminuição da pressão de perfusão cerebral que freqüentemente acompanha o transplante do fígado para hepatite fulminante. MÉTODO: Foram estudados 10 pacientes com hepatite fulminante em encefalopatia grau IV e monitorização de pressão intracraniana submetidos ao transplante do fígado. A hemodinâmica sistêmica e cerebral de 3 pacientes que receberam solução salina hipertônica durante a fase anepática (Grupo SSH) foi analisada comparando com os dados obtidos de 7 pacientes transplantados anteriormente nas mesmas condições (Grupo Controle). Os valores de pressão intracraniana máxima e a correspondente pressão arterial média foram coletados em quatro tempos: (T1) nos últimos 10 min da fase de disseccão, (T2) nos primeiros 10 minutos da fase anepática, (T3) no final da fase anepática e (T4) nos primeiros 5 min da reperfusão RESULTADO: Imediatamente após a infusão da solução salina hipertônica a pressão intracraniana diminuiu 50,4%. Nos primeiros 5 min da reperfusão a pressão intracraniana no Grupo SSH se manteve estável e todos os pacientes apresentavam pressão intracraniana menor que 20 mmHg enquanto no Grupo Controle a pressão intracraniana aumentou 46,5% (

Arterial supply of the cervical thymus lobes in swine fetuses (Sus scrofa domesticus) of the Camborough 25 lineage

O objetivo do presente estudo foi conhecer o suprimento arterial dos lobos cervicais do timo, relativamente às suas origens, distribuições e ordenações, em suínos (Sus scrofa domesticus) da linhagem Camborough 25. Foram estudados 29 suínos da linhagem Camborough 25, sendo 17 machos e 12 fêmeas. Os exemplares tiveram o sistema arterial preenchido com solução aquosa corada a 50% de Neoprene Látex, e, em seguida foram submetidos à fixação em solução aquosa a 10% de formaldeído. Observou-se uma grande variação individual na disposição, comprimento e calibre dos vasos supridores do timo, assim como uma grande variação individual na disposição, tamanho e espessura dos lobos cervicais do timo. As artérias cervical superficial (96,55%), carótida comum (54,54%) e occipital (55,17%) contribuíram com o suprimento vascular sanguíneo dos lobos cervicais do timo nos dois antímeros. Ainda foram vistos ramos das artérias lingual (3,45%) e carótida interna (3,45%) nos dois antímeros e da artéria subclávia (6,90%) no antímero esquerdo. Não foram evidenciadas diferenças significativas da vascularização dos lobos em relação aos antímeros e os sexos. Diante dos achados foi possível concluir que cada um dos animais apresentaram características próprias e peculiares, possibilitando assim o estabelecimento de um arranjo particular aos suínos desta linhagem. _________________________________________________________________________________ ABSTRACTThis study aims to discover more about the arterial supply of cervical lobes of the thymus, in relation to its origins, distribution and ordination in swine (Sus scrofa domesticus) of Camborough 25 lineage. Thus, 29 swine (17 males and 12 females) were studied. The arterial system of the models was colored with aqueous solution of Neoprene Latex “450” (50%) and after the models were fixed in 10% formaldehyde aqueous solution. Great individual variations in the length and size of the thymus vessel supply, and also in the layout, size and thickness of the cervical lobes of the thymus, were observed. The superficial cervical artery (96.55%), common carotid artery (54.54%) and occipital artery (55.17%) contribute to the blood supply of the cervical lobes on both sides. In addition, branches from the lingual artery (3.45%) and internal carotid artery (3.45%) on both sides, as well as the subclavian artery (6.90%) on the left side, were observed. No significant differences in vascularization of lobes in relation to antimerals or sexes were evidenced. Considering the findings, it was conclued that each animal had its own characteristics and peculiarities, thus enabling the establishment of a particular arrangement of the swine strain