Amelioration of hemodynamics and oxygen metabolism by continuous venovenous hemofiltration in experimental porcine pancreatitis

AIM: To investigate the potential role of continuous venovenous hemofiltration (CVVH) in hemodynamics and oxygen metabolism in pigs with severe acute pancreatitis (SAP). METHODS: SAP model was produced by intraductal injection of sodium taurocholate [4%, 1 mL/kg body weight (BW)] and trypsin (2 U/kg BW). Animals were allocated either to untreated controls as group 1 or to one of two treatment groups as group 2 receiving a low-volume CVVH [20 mL/(kg·h)], and group 3 receiving a high-volume CVVH [100 (mL/kg·h)]. Swan-Ganz catheter was inserted during the operation. Heart rate, arterial blood pressure, cardiac output, mean pulmonary arterial pressure, pulmonary arterial wedge pressure, central venous pressure, systemic vascular resistance, oxygen delivery, oxygen consumption, oxygen extraction ratio, as well as survival of pigs were evaluated in the study. RESULTS: Survival time was significantly prolonged by low-volume and high-volume CVVHs, which was more pronounced in the latter. High-volume CVVH was significantly superior compared with less intensive treatment modalities (low-volume CVVH) in systemic inflammatory reaction protection. The major hemodynamic finding was that pancreatitis-induced hypotension was significantly attenuated by intensive CVVH (87.4±12.5 kPa vs116.3±7.8 kPa,P＜0.01). The development of hyperdynamic circulatory failure was simultaneously attenuated, as reflected by a limited increase in cardiac output, an attenuated decrease in systemic vascular resistance and an elevation in oxygen extraction ratio. CONCLUSION: CVVH blunts the pancreatitis-induced cardiovascular response and increases tissue oxygen extraction. The high-volume CVVH is distinctly superior in preventing sepsis-related hemodynamic impairment.

Venovenous bypass ahead of mobilization of the liver in orthotopic liver transplantation

BACKGROUND: To evaluate feasibility and safety of venovenous bypass prior to mobilization of the liver during orthotopic liver transplantation (OLT). METHODS: Fifty-four patients were classified into two groups. Group A consisted of 23 patients receiving OLT with classical venovenous bypass. Group B consisted of 31 patients who received a modified-procedure: venovenous bypass ahead of the mobilization of the liver during ULT. The blood loss, duration of venovenous bypass, cold ischemia time, anhepatic phase, and transfusion during operation in the two groups were compared. Complications after the operation were also compared between the two groups. RESULTS: The duration of venovenous bypass and cold ischemia time in group A were longer than those in group B [(99.78±21.36 min) vs (96.32±22.25 min) and (484.78±134.01 min) vs (443.15± 85.27 min)]. The anhepatic phase lasted for about 100 min averagely in the two groups. The volumes of blood loss and transfusion during the operation were larger in group A than in group B [(5096±4243 ml) vs (1726±1125 ml) and (3676±2938.74 ml) vs (1217.69±829.72 ml)]. Postoperative complications occurred in 26 patients of group A and in 19 patients of group B. CONCLUSION: This modified-procedure or venovenous bypass ahead of mobilization of the liver in OLT can reduce the blood loss during OLT and the incidence of postoperative complications without prolongation of the anhepatic phase and duration of venovenous bypass.

Preoperative detection of intrahepatic venovenous shunt treated by microwave precoagulation during right hepatectomy

A 53-year-old woman underwent a 2-stage right hepatectomy for bilobar metastasis of an ileal neuroendocrine carcinoma. Preoperative three-dimensional computed tomography reconstruction helped to diagnose an intrahepatic venovenous shunts from the right and middle hepatic veins to the left hepatic vein, which could cause a intraoperative bleeding. Hemostasis was performed by means of precoagulation with microwaveassisted coagulation.

Right Radical Nephrectomy with Type-IV IVC Tumor Thrombectomy Using Venovenous Bypass Instead of Cardiopulmonary Bypass—A Case Report

A renal mass with level Level IV IVC thrombus is usually managed with radical nephrectomy and IVC thrombectomy. This procedure requires the assistance of a cardiac surgeon and is usually done under complete cardiopulmonary bypass. However, the use of cardiopulmonary bypass is associated with reduced cardiac venous return and can consequently decrease cardiac output, adversely affecting haemo-dynamic stability and systemic arterial perfusion. This can lead to relative ischemia of the abdominal viscera, lower limbs and kidneys. We report a case where radical nephrectomy with IVC thrombectomy was done under venovenous bypass, thus avoiding the complications associated with the cardiopulmonary bypass.

Influence of continuous veno-venous hemofiltration on the course of acute pancreatitis

AIM： To investigate whether continuous veno-venous hemofiltration （CVVH） in different filtration rate to eliminate cytokines would result in different efficiency in acute pancreatitis, whether the saturation time of filter membrane was related to different filtration rate, and whether the onset time of CWH could influence the survival of acute pancreatitis. METHODS： Thirty-seven patients were classified into four groups randomly. Group 1 underwent low-volume CVVH within 48 h of the onset of abdominal pain （early CVVH, n = 9）. Group 2 received low-volume CVVH after 96 h of the onset of abdominal pain （late CVVH, n= 10）. Group 3 underwent high-volume CVVH within 48 h of the onset of abdominal pain （early CVVH, n = 9）. Group 4 received high-volume CVVH after 96 h of theonset of abdominal pain （late CVVH, n = 9）. CVVH was sustained for at least 72 h. Blood was taken before hemofiltration, and ultrafiltrate was collected at the start of CVVH and every 12 h during CVVH period for the purpose of measuring the concentrations of TNF-α, IL-1β and IL-6. The concentrations of TNF-α, IL-1β and IL-6 were measured by swine-specific ELISA. The Solartron 1 255 B frequency response analyzer （British） was used to observe the resistance of filter membrane. RESULTS： The survival rate had a significant difference （94.44% vs68.42%, P〈0.01） high-volume and low-volume CVVH patients. The survival rate had also a significant difference （88.89% vs 73.68%, P〈0.05） between early and late CVVH patients. The hemodynamic deterioration （MAP, HR, CVP） was less severe in groups 4 and 1 bhan that in group 2, and in group 3 than in group 4. The adsorptive saturation time of filters membranes was 120-180 min if the filtration rate was 1 000-4 000 mL/h. After the first, second and third new hemofilters were changed, serum TNF-α concentrations had a negative correlationwith resistance （r： -0.91, -0.89, and -0.86, respectively in group 1; -0.89, -0.85, and -0.76, respectively in group 2; -0.88, -0.92, and -0.82, respectively in group 3; -0.84, -0.87, and -0.79, respectively in group 4）. The decreasing extent of TNF-α, IL-1β and IL-6 was significantly different between group 3 and group I （TNF-α P〈0.05, IL-1β P〈0.05, IL-6 P〈0.01）, between group 4 and group 2 （TNF-α P〈0.05, IL-1β P〈0.05, IL-6 P〈0.01）, between group 1 and group 2 （TNF-α P〈0.05, IL-1β P〈0.05, IL-6 P〈0.05）, and between group 3 and group 4 （TNF-α P〈0.01, IL-1β P〈0.01, IL-6 P〈0.05）, respectively during CVVH period. The decreasing extent of TNF-α and IL-1β was also significantly different between survival patients and dead patients （TNF-α P〈0.05, IL-1β P〈0.05）. In survival patients, serum concentration of TNF-α and IL-1β decreased more significantly than that in dead patients. CONCLUSION： High-volume and early CWH improve hemodynamic deterioration and survival in acute pancreatitis patients. High-volume CVVH can eliminate cytokines more effidently than low-volume CVVH. The survival rate is related to the decrease extent of TNF-α and IL-1β. The adsorptive saturation time of filter membranes are different under different filtration rate condition. The filter should be changed timely once filter membrane adsorption is saturated.

Application of extracorporeal membrane oxygenation in the endoscopic treatment of severe benign airway stenosis:A case report and literature review

Ventilation strategies in patients with severe tracheal stenosis should be tailored to the patient according to the underlying cause and narrowing location.This report is on a case of a 68-year-old male patient,who was admitted for radiotherapy because of esophageal cancer and then developed severe stenosis at the cervical trachea.We used venovenous extracorporeal membrane oxygenation to secure the airway and ensure adequate oxygenation.Then urgent endoscopic balloon dilation of airway stenosis was successfully performed under general anesthesia.This case shows that venovenous extracorporeal membrane oxygenation can be used in endoscopic tracheal procedures for patients with severe benign stenosis in the upper-trachea who are unable to tolerate conventional ventilation.

Veno-Venous Extracorporeal Membrane Oxygenation: Anesthetic Management for Massive Intracranial Hemorrhage in H1N1 Infection

Background: Extracorporeal membrane oxygenator (ECMO) use is dramatically increasing in recent years. This case report describes a patient on veno-venous (VV) ECMO for H1N1 who underwent emergent craniotomy twice for intracranial hemorrhage. Case presentation: A 38-year-old male presented to a community hospital for worsening shortness of breath. He had experienced cough, malaise and fatigue for two weeks prior to presentation. On arrival, his arterial oxygen saturation was 64%. He was placed on oxygen via non-rebreather mask and started on Tamiflu plus antibiotics. He was intubated for worsening respiratory failure. Despite maximal ventilator settings, the arterial oxygen saturation was approximately 90%. He was placed in the prone position and nitric oxide was initiated. Severe acute respiratory distress syndrome (ARDS) secondary to influenza was diagnosed by viral PCR, clinical presentation, and diagnostic imaging. Within 24 hours of his intubation, a decision was made to initiate veno-venous (V-V) ECMO for respiratory support. Five days following the initiation of ECMO, asymmetric pupils and a nonreactive right pupil were noted. A massive right frontal intraparenchymal hemorrhage with midline shift and downward uncal herniation was found on computed tomography (CT). A decision was made to surgically intervene. He was taken to the operating room for immediate right frontal craniotomy and clot evacuation under general anesthesia. Conclusion: With the dramatic increase in ECMO use, anesthesiologists are encountering patients on ECMO in the operating room with more frequency. When the situation does arise, it is imperative that the anesthesiologist is knowledgeable about ECMO and how to appropriately administer anesthesia for these critically ill patients. Challenges confronting the anesthesiologist with ECMO patients include managing bleeding or coagulopathy, ventilation and oxygenation, volume status, transporting and positioning these patients, and altered pharmacokinetics of anesthetic drugs.

Caval reconstruction techniques in orthotopic liver transplantation

There are several caval reconstruction techniques currently in use for orthotopic liver transplantation. These include caval replacement or the conventional technique, performed with or without venovenous bypass, piggyback technique with anastomosis with two or three hepatic veins with or without cavotomy and modifications of the piggyback technique including end-to-side and side-to-side cavocaval anastomosis. There are few randomized controlled trials comparing the use of these techniques and our knowledge of their comparability is based on a few multi- and many single-center retrospective and prospective reviews. Although there are advantages and disadvantages for each technique, it is advisable that the surgeon perform the technique with which they have the most the experience and at which they are the most skilled as excellent outcomes can be obtained with any of the caval reconstruction options discussed.

CRRT in Treatment of Severe Renal Failure

Objective:CRRT in treatment of severe renal failure. Methods:A high flux dialyzer with a single pump was used to make an 100～200 ml/min flux and 10～20 ml/min ultrafiltration.The average treatment period was 8.4 hours, while the longest treatment lasted 72 hours with 12～16 L/d of replacement-solution and 0.2～4.3 L/d of net ultrafiltration. CVVHD was applied to some patients with high level of toxin, with blood flow at 50~100 ml/min and ultrafiltration rate at 8～12 ml/min and hemodialysis flux at 10～20 ml/min; 1.5% glucose dialysis solution was used as the replacement-solution and the delivering rate was controlled at 20～30 ml/min. Most treatments continued for 9 hours. Results: 5 patients with severe hypotension cant tolerate the treatment, 13 traumas complicated with renal failure died, 4 septic shock patients with MODS died,16 patients recovered or shifted to regular dialysis. Conclusions: CRRT can pull the water from intracellular into the blood continuously, So it can reduce the interference on the stability of cardiovascular system. and it works effectively on correcting the pathogenic distribution of body fluid quickly and ameliorating tissue edema of lung and brain.

Transdiaphragnatic exposure for direct atrioatrial anastomosis in liver transplantation

Background Liver transplantation in Budd-Chiari syndrome remains controversial; however, some improved techniques lead to better results. We report medium-term follow-up results of liver transplantation with atrioatrial anastomosis for Budd-Chiari syndrome and explore the indications of liver transplantation with atrioatrial anastomosis for patients with end stage liver disease.Methods Nine patients （six Budd-Chiari syndromes, one end stage hepatolithiasis, one hepatocellular carcinoma and one incurable alveolar echinococcosis） underwent liver transplantation with atrioatrial anastomosis in West China Hospital of Sichuan University from 1999 to 2006. Eight liver transplants used cadaveric orthotopic livers and one a living donor liver. The operative technique was transdiaphragmatic exposure for direct atrioatrial anastomosis and replacement of inferior vena cava by cryopreserved vena cava graft with the help of venovenous bypass.Results All liver transplantations were successful. Two patients contracted pulmonary infection and acute rejection took place in another case. With proper treatment, all patients recovered well and had good quality of life. To date, they have been followed up for more than 24 months. The only death followed recurrence of hepatic carcinoma three years after liver transplantation.Conclusions Transdiaphragmatic exposure for direct atrioatrial anastomosis and the cryopreserved vena cava graftreplacement of inferior vena cava are possible for patients with end stage liver disease thus extending the indications of liver transplantation.