Use of an intraoperative veno-venous bypass during liver transplantation: an observational, single center, cohort study.

BACKGROUND: As previous studies demonstrated conflicting results, we investigated the hemodynamic and renal outcomes of the intra-operative use of a veno-venous bypass during liver transplantation. METHODS: The intraoperative levels of mean artery pressure, cardiac index, inferior vena cava and renal perfusion pressures were compared in liver transplant patients receiving or not the bypass. RESULTS: We enrolled 38 patients: 20 with the bypass and 18 without. No differences characterized the two groups regarding gender (P=0.95), age (P=0.32), BMI (P=0.09), liver disease indicating LT and preoperative serum creatinine levels. Patients with the bypass received more intraoperative fluids (crystalloids and colloids) but with no difference in terms of intraoperative blood products and vasopressors requirements (P=0.33). After clamping of the inferior vena cava, patients with the bypass showed higher mean artery pressure. Simultaneously, pressure in the inferior vena cava below the clamp level sharply increased vs. baseline (P<0.0001) independently of the use of the bypass and remained high until clamp release. Consequently, renal perfusion pressure dropped abruptly (P<0.0001) after vena cava clamping and returned to baseline only upon clamp removal. Overall, 18 subjects developed postoperative acute kidney injury which was equally distributed between patients with (n=9) or without (N.=8) the bypass. CONCLUSIONS: Our data suggest that the use of a veno-venous bypass fails to release the increased renal venous backflow from inferior vena cava clamping resulting in renal congestion with reduced renal perfusion pressure.

Intravenous fenoldopam for early acute kidney injury after liver transplantation.

PURPOSE: Acute kidney injury remains a serious complication after orthotopic liver transplantation. To date, several 'renal-protective' agents have been explored in this setting but with conflicting and disappointing results. Therefore, our aim is to evaluate the effects of fenoldopam in liver transplant patients with an established renal injury. METHODS: In this prospective study, intravenous fenoldopam 0.1 µg/kg/min was administered to consecutive liver transplant patients with postoperative (within 7 days from surgery) stage 2 acute kidney injury (AKI) according to the Acute Kidney Injury Network classification. Actual glomerular filtration rate (GFR; calculated by the iohexol plasma clearance), serum creatinine (SCr) and cystatin C (SCyC) were used to assess the effect of the medication on the patients. RESULTS: During the study, 295 patients underwent liver transplant. Fifty-one patients (17.6%) met the inclusion criteria and the data from 48 patients were analysed. SCr and SCyC levels decreased (p < 0.001 after 48 h; p < 0.0001 after 72 h) and GFR increased (p < 0.001 after 24 h; p < 0.0001 after 72 h). When compared to a cohort of comparable patients with AKI from our historical series, the patients in the present study showed better SCr and SCyC levels. It was not necessary to discontinue the infusion of fenoldopam in any patient because of the occurrence of adverse events potentially attributable to it. CONCLUSION: We showed that fenoldopam was capable of improving some renal function parameters in postoperative liver transplantation patients with on-going AKI. This preliminary study now sets the stage for a multicenter, randomized, placebo-controlled trial in order to provide definite evidence.

Stress-inducing factors in ICUs: what liver transplant recipients experience and what caregivers perceive.

The aim of this study was to compare a number of potentially stress-generating factors related to an intensive care unit (ICU) stay from the points of view of patients undergoing liver transplantation or elective major abdominal surgery and their caregivers in order to identify differences and similarities that may help to optimize patient care. The ICU Environmental Stressor Scale questionnaire was administered to 104 liver transplant recipients, 103 major abdominal surgery patients, 35 nurses and 21 physicians. The ICU staff were asked to complete the questionnaire on the basis of their perception of patient stressors. Both patient groups identified Being unable to sleep, Being in pain, Having tubes in nose/mouth, Missing husband/wife, and Seeing family and friends only a few minutes a day as the major stressors; the healthcare providers correctly identified the most stressing factors for the patients, but gave them higher scores. The mean scores were 71.9 +/- 18.7 for the transplant recipients, 66.3 +/- 20.9 for the patients undergoing elective major abdominal surgery, 99.7 +/- 19.2 for the nurses, and 92.7 +/- 16.1 for the physicians (P < 0.001). The qualitative evaluations of potentially stress-inducing ICU situations were substantially the same in the 2 patient groups, but the transplant recipients seemed to feel them more acutely. Although the caregivers identified the most discomforting situations, they overestimated the degree of stress they cause. The staff of each ICU should therefore seek to understand and reduce (even by means of simple interventions) the particular causes of psychophysical stress felt by their patients.

Postoperative intra-abdominal pressure and renal function after liver transplantation.

HYPOTHESIS: Intra-abdominal hypertension frequently threatens renal function early after orthotopic liver transplantation (OLT). DESIGN: A prospective study of consecutive patients who underwent OLT. SETTING: The intensive care unit of a National Health Service teaching hospital. PATIENTS AND MAIN OUTCOME MEASURES: The intra-abdominal pressure (IAP) of 108 consecutive patients who underwent OLT was postoperatively measured 3 times a day for 72 hours using the urinary bladder technique. Intra-abdominal hypertension was defined as an IAP of 25 mm Hg or higher. RESULTS: Thirty-four patients (31%) had a high IAP. Acute renal failure developed in 17 recipients (16%), 11 (65%) of whom had intra-abdominal hypertension (P<.01), with a mean +/- SD IAP of 27.9 +/- 9.9 mm Hg vs 18.6 +/- 5.2 mm Hg in those without acute renal failure (P<.001). The subjects with a high IAP were more frequently administered loop diuretics to maintain adequate diuresis (P<.001) and had a low mean arterial pressure on the day of surgery (P<.01), despite the fact that they were given more intravenous fluids (P<.01) and did not differ in the need for inotropic drugs. Logistic regression analysis showed that intraoperative transfusions of more than 15 U, respiratory failure, and intra-abdominal hypertension (P<.01) were independent risk factors for renal failure. The length of intensive care unit stay was similar in the patients with a normal and a high IAP, but mortality was higher among the latter (P =.02). CONCLUSIONS: Intra-abdominal hypertension is common after OLT and is significantly associated with renal failure, reduced urinary output, and intensive care unit mortality. It is, therefore, worth monitoring IAP in those undergoing OLT.

Intra-abdominal pressure monitoring in liver transplant recipients: a prospective study.

OBJECTIVE: No data are available on the incidence and clinical relevance of increased intra-abdominal pressure after orthotopic liver transplantation. This study assessed abdominal hypertension in a population of transplanted patients as this may be an important cofactor in early postoperative complications. DESIGN AND SETTING: Prospective clinical study in an intensive care unit of a national health system teaching hospital PATIENTS AND MEASUREMENTS: Abdominal pressure was measured every 6 h using the urinary bladder method and was considered elevated when it was 25 mmHg or higher. Hemodynamic status was evaluated at the same times. Renal function was assessed on the basis of hourly urinary output by calculating serum creatinine on postoperative days 2 and 4 and the filtration gradient; patient outcomes were also considered. RESULTS: Intra-abdominal hypertension was observed in 32% of cases; the subjects with high abdominal pressure had significantly lower mean artery pressure values but did not differ in terms of central venous pressure or cardiac output. High intra-abdominal pressure was more frequently associated with renal failure, a lower filtration gradient, delayed postsurgical weaning from ventilation, and a worse outcome. CONCLUSIONS: Abdominal hypertension is frequent after liver transplantation and may be associated with a complicated post-operative course.

Antifungal prophylaxis in liver transplant recipients: a randomized placebo-controlled study.

The aim of this study was to evaluate the efficacy of two antifungal prophylaxis regimens in liver transplant recipients. One hundred and twenty-nine consecutive recipients were randomized to receive sequential treatment with intravenous liposomal amphotericin B + oral itraconazole, intravenous fluconazole + oral itraconazole, or intravenous and oral placebo. Frequency and incidence of mycotic colonization, local and systemic infection of mycotic origin, causes of death, and possible risk factors for mycotic infection were evaluated. The incidence of mycotic colonization was higher in the placebo group ( P<0.01), but there was no significant difference in the incidence of infection between the three groups. Pre-transplant colonization, severity of liver disease, and graft rejection were all risk factors for the development of fungal infection. The routine use of antifungal prophylaxis for all liver transplant recipients does not seem to be justified.