Hyperdynamic circulation in cirrhosis: predictive factors and outcome following liver transplantation.

BACKGROUND: Liver cirrhosis is associated with a hyperdynamic circulation (HC). In this observational study, we aimed to investigate the predictive factors of HC, its impact on intraoperative hemodynamic and postoperative outcome, early ICU and in-hospital mortality, in cirrhotic patients undergoing orthotopic liver transplantation (OLT). METHODS: Two hundred and forty-two patients with cirrhosis undergoing cadaveric OLT were included. Before starting the transplant procedure and under general anesthesia, a pulmonary artery catheter was introduced to assess hemodynamic parameters. The baseline assessment was carried out approximately 30 minutes after the catheter placement and repeated during the anhepatic phase, 10 minutes after the reperfusion and at the end of surgery. The patients were divided into two groups: in group 1 the patients had SVR>900dynes s-1 m-2 cm-5, in group 2 SVR ≤900 dynes s-1 m-2 cm-5. RESULTS: Eighty-two patients (33%) presented severe HC. In multivariate analysis 2 factors were associated with the occurrence of HC: beta-blockers use (Exp [B]=4.42 (95% CI 1.18-17); P=0.001, [34% and 12% in groups 1 and 2, P<0.001, respectively]) and model for end-stage liver disease (MELD) score (Exp [B]=1.066; 95% CI=1.025-1.109; P=0.001). CONCLUSION: MELD score was an independent predictor of HC, and beta-blockers resulted associated with lower incidence of HC in cirrhotic patients undergoing cadaveric OLT. Intraoperative HC correlates with hemodynamic alterations, requiring more blood products and vasopressor use, this may increase the risk of renal failure, early ICU death and in-hospital mortality.

Anesthesia for liver transplantation: the experience of the University of Bologna in the MELD era.

AIM: The hepatic cirrhosis is associated with an important cardiovascular alterations. In this report, we review our transplant center experience with liver transplantation in the Model for End-Stage Liver Disease (MELD) era, in particular this study investigate the relationship between severity of liver disease assessed by MELD score and postoperative events. METHODS: Our retrospective review was performed on 242 cirrhotic patients underwent liver transplanation at the Department of Surgery and Transplantation of the University of Bologna. Biochemical and hemodynamic variables were evaluated by Swan-Ganz catherization. Dindo's classification of postoperative complications was used for the evaluation of postoperative course. RESULTS: Morbidity occurred in 158 patients (65.2%) and 13 patients died during the hospital stay. Considering the highest grade of complication occurred, non life-threatening complications occurred in the 47.9% of cases (116 patients) and life-threatening complications, excluding patient death, in 17.3% (42 patients). Patients with MELD >30 showed a longer ICU stay, tracheal intubation and in-hospital stay. CONCLUSION: In conclusion MELD score is tightly related to postoperative complications.

Hyperdynamic circulation in acute liver failure: reperfusion syndrome and outcome following liver transplantation.

BACKGROUND/AIMS: Liver transplantation (OLT) is a valid therapeutic option for patients with fulminant hepatic failure (FHF). The most critical phase during OLT is considered to be graft reperfusion, where in large changes in patient homeostasis occur. The aims of the present study were to evaluate the hemodynamic and cardiac changes among a large series of patients with FHF, to determine independent clinical predictors of the occurrence of postreperfusion syndrome (PSR) and its relationship to clinical and hemodynamic parameters and transplant outcomes. METHODS: Systemic hemodynamic and cardiac functions were evaluated by Swan-Ganz catheterization in 58 patients before OLT. The patients were divided into two subgroups on the basis of PSR, which was defined as a mean arterial blood pressure 30% lower than the immediate previous value lasting for at least 1 minute within 5 minutes after unclamping. RESULTS: PSR occurred in 24 patients (41%). Significant differences upon bivariate analysis was observed for the Model for End-stage Liver Disease score, which was significantly higher among patients with PSR, namely 32 (range = 18-43) versus 23 (range = 12-32) (P = .001). Higher serum creatinine values were significantly different among patients with PSR: 1.4 (range = 1.2-2.2) versus 2.1 (range = 2.5-3.2) mg/dL (P < .01). CONCLUSION: Systemic hemodynamic alterations of FHF progressively worsen with increasing severity of liver disease. PSR developed in approximately 40% of patients; its prevalence was significantly related to the severity of the disease. Finally, patients with renal failure showed greater risk to develop an PSR during OLT.

Pretransplant model for end-stage liver disease score as a predictor of postoperative complications after liver transplantation.

The model for end-stage liver disease (MELD) is used to determine organ allocation priorities for orthotopic liver transplantation (OLT), although its value to predict posttransplantation mortality and morbility is controversial. The aim of this study was to analyze postoperative courses and (to evaluate the relationships between MELD score and postoperative) complications. We retrospectively examined the courses of 242 patients including 186 males and 56 females of overall mean age of 53 +/- 10 years who underwent primary liver transplantation. The classification of Dindo-characterized 5 grades of severity to evaluate postoperative events. The data showed that 171 patients (70.7%) experienced complications, while 71 (29.3%) had none. We observed that MELD score and complications were related (P < .05). Patients with complicated courses post-OLT displayed a 22.80 mean value of the MELD score, while those without complications showed a 17.64 mean value. The MELD score was also significantly associated with the time of intensive care unit stay and in hospital. Finally, we noted that MELD score and mortality were significantly correlated (P < .05). In conclusion, MELD score can be considered to be an objective system to predict the prevalence and severity of postoperative complications after liver transplantation.

Fluid management of patients undergoing intestinal and multivisceral transplantation.

Small bowel transplantation can be associated with large fluid shifts due to massive blood loss, dehydration, vascular clamping, long ischemia times, intraoperative visceral exposure, intestinal denervation, ischemic damage, and lymphatic interruption. Fluid management is the major intra- and postoperative problem after small bowel and multiple organ transplantation, because of the highly variable fluid and electrolyte needs of the transplant recipient. Third-space fluid requirements can be massive; inadequate replacement leads to end-organ dysfunction, particularly renal failure. Several liters of fluid may be required in the initial 24 to 48 hours postoperatively to simply maintain an adequate central pressure to provide a satisfactory urine output. During this time patients may develop extensive peripheral edema, which dissipates over the next few days as the fluids are mobilized and requirements stabilize. Based on our experience in 29 cases of intestinal transplantation and 4 cases of multivisceral transplantation, we have herein described the intraoperative fluid management and hemodynamic changes. Our study confirmed a large quantity of fluid administration during and after small bowel transplantation that required adequate volume monitoring.

Acute renal failure after liver transplantation in MELD era.

Model for End-Stage Liver Disease (MELD) score was used in our center from 2003 to assess the position of orthotopic liver transplantation (OLT) candidates on a waiting list. A key component of MELD score in the assessment of the degree of the illness is renal function. In this study, we measured the effects of this new scoring system on renal function and therapeutic strategies. We evaluated the incidence of acute renal function (ARF) after OLT requiring renal replacement therapy (hemofiltration or hemodialysis) in two patient groups: 240 transplanted before MELD era and 224 after the introduction of this parameter to select candidates. ARF occurred in 8.3% of patients in the pre-MELD group versus 13% in the MELD group, while the mortality rates were 40% and 27%, respectively. The creatinine level before OLT seemed to be a good predictor of ARF (P < .001), and blood transfusion rates (P < .05) as well as intraoperative diuresis (P < .05). In our analysis we did not observe a correlation between MELD score and postoperative ARF.

Analysis of the causal factors of prolonged mechanical ventilation after orthotopic liver transplant.

BACKGROUND: Prolonged mechanical ventilation and the consequently long stay in the intensive care unit (ICU) appear to be important infection risk factors in patients undergoing liver transplant. METHODS: We analyzed the data relating to 70 liver transplants performed on 67 patients during the past year's activities. For each patient we have considered the presence of preoperative pulmonary alterations, the first radiological result of the postoperative thorax, the PaO(2)/FiO(2) ratio recorded in the peroperative phase immediately after induction of general anesthesia (T0), and arrival at the ICU at the end of the operation (T1). We also considered the enzyme trend (glutamate-oxalacetic transaminase [GOT] and glutamate-pyruvate transaminase [GPT]) recorded every 6 hours for the first 42 hours of the postoperative period (times T1 to T7). RESULTS: There was an evident correspondence between the values of PaO(2)/FiO(2) < or = 300 ratio at time T1 and the subsequent duration of mechanical ventilation (P = .001). There was also a correlation between the PaO(2)/FiO(2) < or = 300 ratio at time T1 and the trend of the GPT in the first 24 hours postsurgery (P = .021; P = .026; P = .018; P = .048) or GOT trend over the same span of time (P = .027; P = .035; P = .048). CONCLUSIONS: Graft malfunction as expressed by the enzyme trend affects both the duration of mechanical ventilation and the postoperative PaO(2)/FiO(2) ratios. This metric may be useful to reinforce infection surveillance and to perform an early percutaneous tracheostomy in these patients.

Intraoperative coagulation evaluation of ischemia-reperfusion injury in small bowel transplantation: a way to explore.

BACKGROUND AND AIM OF STUDY: The success of intestinal transplantation is affected by the extreme susceptibility of the small bowel to ischemia-reperfusion (I/R) injury. Platelet aggregation decreases after reperfusion in small intestinal ischemia and liver transplantation. Thromboelastography (TEG) is a coagulation test performed whole on blood. The aims of this study were to assess coagulation derangements during bowel transplantation to define appropriate modalities of intraoperative coagulation monitoring. A secondary endpoint was to determine whether measurements of coagulation derangements were useful to estimate small intestinal I/R injury. MATERIALS AND METHODS: We recruited 19 patients who had undergone elective small bowel transplantation for primary short-gut syndrome. We divided our patients into two groups depending on their reperfusion injury as evaluated with a biopsy after reperfusion: group A composed of eight patients who had a reperfusion injury: group B composed of 11 patients who did not experience this problem. We measured five thromboelastogram indicators (r, k, angle, MA, CL30) at defined intervals: dissection phase (T1), vascular anastomoses phase (T2) as well as 30 minutes (T3) and 120 minutes (T4) after reperfusion during the intestinal reconstruction phase. RESULTS: We did not observe any significant difference between intraoperative blood loss, core temperature, or volume of fluid fresh frozen plasma, or platelet administration. Angle and MA were decreased significantly among patients with reperfusion injury. DISCUSSION: Patients showed a hypocoagulation pattern during all the manipulations. This derangement did not depend on the ischemia time. In patients with I/R injury the angle and MA did not change during ischemia, but did change significantly upon reperfusion. Several mechanisms may cause coagulation derangements. During the ischemic period, there may be damage to the vascular bed of the ischemic organ. When arterial blood passes through the damaged vascular bed after reperfusion, platelet activation occurs to varying degrees, resulting in reduced platelet function. CONCLUSION: Further studies are needed to confirm this preliminary work, which was limited by the low number of patients, in order to elucidate relevant mechanisms and develop predictive algorithms.

Right ventricular end-diastolic volume index as a predictor of preload status in patients with low right ventricular ejection fraction during orthotopic liver transplantation.

OBJECTIVE: The objective of this study was to compare the accuracy of 2 variables: pulmonary artery occlusion pressure (PAOP) and right ventricular end diastolic volume index (RVEDVI) as predictors of the hemodynamic response to fluid challenge as well as definition of the overall correlation between RVEDVI and change in PAOP, right ventricular ejection fraction (RVEF), central venous pressure (CVP), and determination of the right ventricular function during orthotopic liver transplantation. MATERIALS AND METHODS: A modified pulmonary artery catheter equipped with a fast response thermistor was used to determine RVEF, allowing calculation of RVEF end-diastolic volume index (EDVI, as the ratio of stroke index [SI] to EF). The above-mentioned hemodynamic measures were taken in 4 phases: T0, after induction of anesthesia; T1, during anhepatic phase; T2, 30' after graft reperfusion; and T3, at the end of surgery. RESULTS: The variation of the REF value was 36 +/- 4% and 39 +/- 6%. Linear regression analysis showed a significant correlation between RVEDVI (range, 133 +/- 33-145 +/- 40 mL/m(2)) and stroke volume index (SVI) in each phase (r(2) = 0.49, P < .01; r(2) = 0.57, P < .01) at T0 and T1, respectively, and at T2 and T3 (r(2) = 0.51, P < .01; r(2) = 0.44, P < .01), respectively. No significant variations in the linear regression analysis between RVEDVI, PAOP, CVP, and RVEF were observed. No relationship was found between PAOP (range, 10 +/- 2-6 +/- 2 mm Hg) and SVI. CONCLUSION: RVEDVI may be the best clinical estimate of right ventricular preload. In fact, minor changes of RVEF have been recorded, confirming that RV function was not altered during uncomplicated orthotopic liver transplantation.