O volume de fluxo e a velocidade de pico sistólico ao ultrassom vascular com Doppler intraoperatório como preditores de perviedade precoce na fístula arteriovenosa autógena para hemodiálise / Intraoperative vascular Doppler ultrasound blood flow and peak systolic velocity predict early patency in hemodialysis arteriovenous fistula

Resumo Contexto A insuficiência renal crônica é um problema de saúde pública mundial. A hemodiálise é a principal terapia renal substitutiva. As fístulas arteriovenosas (FAV) são uma possível escolha, mas apresentam altas taxas de falência. Objetivos Este estudo tem como objetivo avaliar a relação entre as variáveis hemodinâmicas ao ultrassom vascular com Doppler no intraoperatório e a perviedade precoce da FAV para hemodiálise. Métodos Tratou-se de um estudo prospectivo observacional. Os pacientes consecutivos foram submetidos a FAV com ultrassonografia vascular com Doppler em intraoperatório nos dias 1, 7, 30 e 60. Eles foram divididos em grupos quanto à presença ou não de perviedade primária e secundária, e o volume de fluxo (VF) e a velocidade de pico sistólico (VPS) foram comparados. Foram realizadas curvas receiver operating characteristic (ROC), com definição de valores de VPS e VF com sensibilidade (S) e especificidade (E). Resultados Foram analisados 47 pacientes, os quais preencheram os critérios de inclusão. Os valores de VPS e VF intraoperatório foram maiores nos pacientes com perviedade primária e secundária comparados àqueles com falência. Os seguintes valores apresentaram maiores sensibilidade e especificidade para predizer perviedade primária aos 30 dias: 106 cm/s para VPS venoso, S: 75%, E: 71,4%; e 290,5 mL/min para VF arterial, S: 80,6%, E: 85,7%. Para perviedade secundária aos 30 dias, foram observados: 106 cm/s para VPS arterial, S: 72,7%, E: 100%; e 230 mL/min para VF venoso, com S: 86,4%, E: 100%. Para a perviedade primária no 60º dia, foram observados: 106 cm/s para VPS venoso, S: 74,4%, E: 62,5%; e 290,5 mL/min para VF arterial, S: 80%, E: 75%. Conclusões A velocidade de pico sistólico e o VF ao ultrassom vascular com Doppler intraoperatório são preditores de perviedade precoce na FAV para hemodiálise.

Abstract Background Chronic kidney disease is a major public health problem. Hemodialysis is the most common renal replacement therapy. Arteriovenous fistulas (AVF) are a possible access option, but early failure rates remain high. Objectives to investigate the value of intraoperative vascular Doppler ultrasound for predicting early AVF patency. Methods Prospective observational study. Consecutive patients undergoing AVF were assessed with vascular Doppler ultrasonography intraoperatively and on days 1, 7, 30, and 60. Patients were divided into groups according to presence or absence of primary and secondary patency. Blood flow (BF) and peak systolic velocity (PSV) were compared. ROC curves were plotted and used to define the PSV and BF values that yielded greatest sensitivity (Sens) and specificity (Spec). Results 47 patients met the inclusion criteria and were analyzed. Higher intraoperative PSV and BF values were observed in patients who had primary and secondary patency than in patients with access failure. The values with greatest sensitivity and specificity for predicting 30-day primary patency were 106 cm/s for venous PSV (Sens: 75% and Spec: 71.4%) and 290.5 ml/min for arterial blood flow (Sens: 80.6% and Spec 85.7%). Values for 30-day secondary patency were 106 cm/s for arterial PSV (Sens: 72.7%, Spec: 100%) and 230 ml/min for venous blood flow (Sens: 86.4%, Spec100%). Values for 60-day primary patency were 106 cm/s for venous PSV (Sens: 74.4%, Spec: 62.5%) and 290.5 ml/min for arterial blood flow (Sens: 80%, Spec: 75%). Conclusions Peak systolic velocity and blood flow measured using intraoperative vascular Doppler ultrasound can predict early patency of hemodialysis arteriovenous fistulas.

Pulse pressure variation guided fluid therapy during kidney transplantation: a randomized controlled trial / Reposição de volume orientada pela variação da pressão de pulso durante transplante renal: estudo randomizado controlado

Abstract Purpose: Kidney transplantation is the gold-standard treatment for end stage renal disease. Although different hemodynamic variables, like central venous pressure and mean arterial pressure, have been used to guide volume replacement during surgery, the best strategy still ought to be determined. Respiratory arterial Pulse Pressure Variation (PPV) is recognized to be a good predictor of fluid responsiveness for perioperative hemodynamic optimization in operating room settings. The aim of this study was to investigate whether a PPV guided fluid management strategy is better than a liberal fluid strategy during kidney transplantation surgeries. Identification of differences in urine output in the first postoperative hour was the main objective of this study. Methods: We conducted a prospective, single blind, randomized controlled trial. We enrolled 40 patients who underwent kidney transplantation from deceased donors. Patients randomized in the "PPV" group received fluids whenever PPV was higher than 12%, patients in the "free fluid" group received fluids following our institutional standard care protocol for kidney transplantations (10 mL.kg-1. h-1). Results: Urinary output was similar at every time-point between the two groups, urea was statistically different from the third postoperative day with a peak at the fourth postoperative day and creatinine showed a similar trend, being statistically different from the second postoperative day. Urea, creatinine and urine output were not different at the hospital discharge. Conclusion: PPV guided fluid therapy during kidney transplantation significantly improves urea and creatinine levels in the first week after kidney transplantation surgery.

Resumo Objetivo: Transplante renal é o tratamento padrão-ouro na doença renal em estágio terminal. Embora diferentes variáveis hemodinâmicas, tais como pressão venosa central e pressão arterial média, têm sido usadas para orientar a estratégia de reposição volêmica durante a cirurgia, a melhor estratégia ainda não foi determinada. A Variação da Pressão de Pulso (VPP) durante o ciclo respiratório é reconhecida como um bom preditor da resposta à infusão de volume para otimização hemodinâmica perioperatória no centro cirúrgico. O objetivo do estudo foi estudar se a estratégia de reposição de volume orientada por VPP é melhor do que a estratégia liberal de reposição de volume durante cirurgia de transplante renal. O principal objetivo do estudo foi identificar diferença no débito urinário na primeira hora do pós-operatório. Método: Realizamos estudo prospectivo, unicego, randomizado, controlado. Incluímos 40 pacientes submetidos a transplante renal de doador cadáver. Pacientes randomizados para o Grupo VPP receberam volume quando a VPP estava acima de 12%, e os pacientes no Grupo Reposição Liberal receberam volume de acordo com o nosso protocolo institucional padrão de assistência para transplante renal (10 mL.kg-1.h-1). Resultados: O débito urinário foi semelhante em todos os tempos nos dois grupos, a ureia foi estatisticamente diferente a partir do terceiro dia do pós-operatório com pico no quarto dia do pós-operatório e a creatinina apresentou tendência semelhante, tornando-se estatisticamente diferente a partir do segundo dia do pós-operatório. Ureia, creatinina e débito urinário não estavam diferentes na alta hospitalar. Conclusões: A terapia orientada por VPP durante transplante renal melhorou de forma significativa os níveis de ureia e creatinina na primeira semana pós-transplante renal.

Effects of intraoperative diltiazem infusion on flow changes in arterial and venous grafts in coronary artery bypass graft surgery / Efeitos da infusão intraoperatória de diltiazem sobre as mudanças do fluxo em enxertos arteriais e venosos em cirurgia de revascularização do miocárdio

AbstractObjective:This study aimed to show the effects of intra-operative diltiazem infusion on flow in arterial and venous grafts in coronary artery bypass graft surgery.Methods:Hundred fourty patients with a total of 361 grafts [205 (57%) arterial and 156 (43%) venous] underwent isolated coronary surgery. All the grafts were measured by intraoperative transit time flow meter intra-operatively. Group A (n=70) consisted of patients who received diltiazem infusion (dose of 2.5 microgram/kg/min), and Group B (n=70) didn't receive diltiazem infusion.Results:Mean graft flow values of left internal mammary artery were 53 ml/min in Group A and 40 ml/min in Group B (P<0.001). Pulsatility index (PI) values of left internal mammary artery for Group A and Group B were 2.6 and 3.0 respectively (P<0.001). No statistically significant difference was found between venous graft parameters.Conclusion:We recommend an effect of diltiazem infusion in increasing graft flows in coronary artery bypass graft operations.

ResumoObjetivo:Este estudo teve como objetivo mostrar os efeitos da infusão de diltiazem intraoperatória no fluxo arterial e enxertos venosos em cirurgia de revascularização do miocárdio.Métodos:Cento e quarenta pacientes com um total de 361 enxertos [205 (57%) arteriais e 156 (43%) venosos] passaram por uma cirurgia coronária isolada. Todos os enxertos foram medidos pelo medidor de fluxo de tempo de trânsito intraoperatório. Grupo A (n=70), formado por pacientes que receberam infusão de diltiazem (dose de 2,5 micrograma/kg/min), e Grupo B (n=70), por aqueles que não receberam infusão de diltiazem.Resultados:Os valores médios de fluxo de enxerto de artéria mamária interna esquerda foram 53 ml/min no grupo A e 40 ml/min no Grupo B (P<0,001). Valores do índice de pulsatilidade da artéria mamária interna esquerda para o Grupo A e do Grupo B foram de 2,6 e 3,0, respectivamente (P<0,001). Não houve diferença estatisticamente significativa entre os parâmetros do enxerto venoso.Conclusão:Sugerimos um efeito da infusão de diltiazem em aumentar os fluxos de enxerto em operações de bypass de artéria coronária.

Laparoscopic radical prostatectomy: omitting a pelvic drain

PURPOSE: Our goal was to assess outcomes of a selective drain placement strategy during laparoscopic radical prostatectomy (LRP) with a running urethrovesical anastomosis (RUVA) using cystographic imaging in all patients. Materials and Methods: A retrospective chart review was performed for all patients undergoing LRP between January 2003 and December 2004. The anastomosis was performed using a modified van Velthoven technique. A drain was placed at the discretion of the senior surgeon when a urinary leak was demonstrated with bladder irrigation, clinical suspicion for a urinary leak was high, or a complex bladder neck reconstruction was performed. Routine postoperative cystograms were obtained. RESULTS: 208 patients underwent LRP with a RUVA. Data including cystogram was available for 206 patients. The overall rate of cystographic urine leak was 5.8 percent. A drain was placed in 51 patients. Of these, 8 (15.6 percent) had a postoperative leak on cystogram. Of the 157 undrained patients, urine leak was radiographically visible in 4 (2.5 percent). The higher leak rate in the drained vs. undrained cohort was statistically significant (p = 0.002). Twenty-four patients underwent pelvic lymph node dissection (8 drained, 16 undrained). Three undrained patients developed lymphoceles, which presented clinically on average 3 weeks postoperatively. There were no urinomas or hematomas in either group. CONCLUSIONS: Routine placement of a pelvic drain after LRP with a RUVA is not necessary, unless the anastomotic integrity is suboptimal intraoperatively. Experienced clinical judgment is essential and accurate in identifying patients at risk for postoperative leakage. When suspicion is low, omitting a drain does not increase morbidity.

Evaluación de función diastólica intraoperatoria con ecocardiografía transesofágica: ¿es útil? / Intraoperative diastolic dysfunction as a risk factor for hemodynamic instability

Background: Diastolic function can be evaluated intraoperatively using transesoptiageal echocardiography. Aim: To study if intraoperative diastolic dysfunction is associated to a greater number of hemodynamic events during surgery and during the postoperative period. Material and methods: Patients with indication of intraoperative transesophageal echocardiography due to cardiovascular diseases were included in the study. Diastolic function was assessed measuring transmitral intraventricular filling delay and pulmonary vein now. Patients were divided, according to diastolic dysfunction, in those with derangements in relaxation, pseudonormalization and restrictive patterns. Hypertension, hypotension, ST segment depression, alterations in myocardial contractility, pulmonary congestion and postoperative oliguria were recorded. Results: Fifty eight patients aged 68± 12 years (39 males), were studied. Forty four had diastolic dysfunction. Intraoperative hypotension occurred in 82 percent of patients with diastolic dysfunction and 16 percent of patients without it. Likewise, hypotension and oliguria during the postoperative period were more common in patients with diastolic dysfunction. Conclusions: In this group of patients with cardiovascular disease, intraoperative diastolic dysfunction is a risk factor for hemodynamic instability.