Incidental intracardiac thromboemboli during liver transplantation: incidence, risk factors, and management.

Even though numerous cases of massive thromboemboli have been reported in the literature, intracardiac thromboemboli (ICTs) incidentally found during orthotopic liver transplantation (OLT) have not been examined. In this study, we retrospectively examined the incidence, risk factors, and management of incidental ICTs during OLT. After institutional review board approval, adult patients who underwent OLT between January 2004 and December 2008 at our center were reviewed. ICTs were identified and confirmed by the examination of OLT datasheets, anesthesia records, and recorded transesophageal echocardiography (TEE) clips. The clinical presentation, management, and outcomes of the patients with ICTs were reviewed. Risk factors were analyzed by multivariate logistic regression. During the study period, 426 of the 936 adult OLT patients (45.5%) underwent intraoperative TEE monitoring. Incidental ICTs were identified in 8 of these 426 patients (1.9%). Two ICTs occurred before reperfusion, and 6 ICTs occurred after reperfusion. The treatment was at the discretion of the treating physicians; however, none of the patients received an anticoagulant or thrombolytics. Multivariate analysis identified 2 independent risk factors for intraoperative incidental ICTs: the presence of symptomatic or surgically treated portal hypertension (a history of gastrointestinal bleeding, a transjugular intrahepatic portosystemic shunt procedure, or portocaval shunt surgery) before OLT and intraoperative hemodialysis (odds ratios of 4.05 and 7.29, respectively; P < 0.05 for both). In conclusion, incidental ICTs during OLT occurred at a rate of 1.9% and were associated with several preoperative and intraoperative risk factors. The use of TEE allows early identification, which may be important. Our management for incidental ICTs is described; however, no conclusions can be made about the optimal therapy.

Insulin therapy in divided doses coupled with blood transfusion versus large bolus doses in patients at high risk for hyperkalemia during liver transplantation.

OBJECTIVE: To assess the effectiveness of an insulin regimen in divided doses designed to target risk factors of hyperkalemia in patients undergoing liver transplantation. DESIGN: Retrospective comparison of the divided insulin dose regimen with a conventional large-bolus insulin method during liver transplantation. SETTING: University-based, academic, tertiary center. PARTICIPANTS: Adult patients whose baseline potassium levels were >/=4.0 mmol/L and received insulin therapy during liver transplantation at the authors' medical center between January 2004 and April 2007. INTERVENTIONS: Insulin was administered either in divided doses (1-2 units) for each unit of red blood cells transfused or in a large-bolus in patients at high risk for hyperkalemia during liver transplantation. MEASUREMENTS AND MAIN RESULTS: Among 717 patients who underwent liver transplantation, 50 patients received insulin in divided doses, and 101 patients received a large-bolus of insulin. Perioperative characteristics were comparable except for higher insulin doses in the large-bolus group. The divided insulin regimen was associated with significantly lower mean potassium levels within 2 hours before reperfusion of the graft compared with the conventional group (p < 0.005). The mean glucose levels in the divided group were significantly lower in both the pre- and postreperfusion periods than in the conventional group (p < 0.05 to <0.001). CONCLUSIONS: The divided insulin dose regimen that specifically targets the risk factors for prereperfusion hyperkalemia is associated with significantly lower prereperfusion potassium and pre- and postreperfusion glucose levels and provides a useful alternative to the conventional large-bolus method in management of intraoperative hyperkalemia during liver transplantation.

Severe intraoperative hyperglycemia is independently associated with surgical site infection after liver transplantation.

BACKGROUND: Surgical site infection (SSI) is a common postoperative complication associated with increased morbidity and mortality in patients undergoing liver transplantation (LT). Although intraoperative hyperglycemia has been shown to be associated with adverse postoperative outcomes including overall infection rate in LT patients, a relationship between intraoperative hyperglycemia and SSI in LT has not been established. We sought to determine if intraoperative hyperglycemia was associated with SSI after LT. METHODS: Patients undergoing LT at our medical center between January 2004 and November 2007 were included in the study. Recipient, donor, and intraoperative variables including a variety of glucose indices were retrospectively analyzed. Independent risk factors of SSI were identified using a multivariate logistic regression model. RESULTS: Of 680 patients, 76 (11.2%) experienced postoperative SSIs. Among all intraoperative glucose indices analyzed, severe hyperglycemia (>or= 200 mg/dL) was independently associated with postoperative SSI (odds ratio [OR] 2.25, 95% confidence interval [CI] 1.26-4.03, P=0.006). Other independent risk factors include repeat surgery (OR 6.58, 95% CI 3.41-12.69, P<0.001), intraoperative administration of vasopressor (OR 3.14, 95% CI 1.65-5.95, P<0.001), preoperative mechanical ventilation (OR 3.01, 95% CI 1.70-5.33, P<0.001), and combined liver and kidney transplantation (OR 2.95, 95% CI 3.41-12.69, P<0.001). CONCLUSIONS: Severe, but not mild or moderate, intraoperative hyperglycemia is independently associated with postoperative SSI and should be avoided during LT surgery.

Preoperative characteristics and intraoperative transfusion and vasopressor requirements in patients with low vs. high MELD scores.

Recent changes in organ allocation based on the model for end-stage liver disease (MELD) prioritize the most ill patients on the waiting list for liver transplantation. While patients undergoing liver transplantation in the MELD era are more acutely ill, the impact of the policy changes on perioperative management has not been completely assessed. We retrospectively reviewed the records of 124 primary adult liver transplant patients. Patients were divided into low (< or = 30) and high MELD (>30) score groups. Preoperative characteristics and intraoperative management were compared between the 2 groups. Patients with high MELD scores had lower baseline hematocrit and fibrinogen levels and were more likely to require ventilatory and vasopressor support before transplantation. Intraoperative transfusion requirements and use of vasopressors were also significantly increased in patients with high MELD scores compared to patients with low MELD scores. In conclusion, these data suggest that pretransplant MELD scores provide important information for perioperative management of patients undergoing liver transplantation.

Comparison of RBCs and FFP with whole blood during liver transplant surgery.

BACKGROUND: Component therapy has become the accepted standard of care in transfusion medicine. In instances of large blood loss, the transfusion of whole blood rather than the combination of RBCs and FFP is rational and may be preferred. STUDY DESIGN AND METHODS: In a controlled, prospective, randomized study of 33 patients undergoing orthotopic liver transplantation, the effectiveness of component therapy (RBCs and FFP) was compared with the use of whole blood. Coagulation tests (prothrombin time and activated partial thromboplastin time), clotting factor levels (FV, FVIII, fibrinogen), platelet counts, the number of donor exposures, and the total volume of blood transfused for the whole-blood group and the component-therapy group were compared at designated times before surgery, during surgery, and 24 hours after surgery. RESULTS: There was a significant difference (p=0.015) in the median number of donor exposures for RBCs and FFP, with fewer occurring in the whole-blood group (n=14.5) compared with the component group (n=25). There was no significant difference between groups in coagulation profiles during any of the phases of surgery except for a mild decrease in fibrinogen levels in the whole-blood group at the conclusion of surgery. There were no differences between the groups in the median volume of blood component replacement, the median age of blood components, the patients' Hct or the number of RBC-containing components transfused. CONCLUSION: Whole blood, when compared with component therapy, is associated with fewer donor exposures yet provided equally effective replacement therapy for blood loss in liver transplantation patients.

Retrospective analysis of the results of liver transplantation for adults with severe hepatopulmonary syndrome.

The hepatopulmonary syndrome (HPS), consisting of elevated alveolar-arterial oxygen gradient and intrapulmonary vascular abnormalities in the presence of advanced liver disease, is associated with high mortality. Liver transplantation (LT) has been used for the treatment of HPS; however, the success of LT for the treatment of HPS is not uniformly documented. We reviewed our experience over a 5-year period and identified eight adult patients with incapacitating respiratory symptoms compatible with HPS. Inclusion criteria included hypoxemia, normal lung volumes, reduced oxygen diffusing capacity (D(L)CO), and the presence of intrapulmonary shunting. Underlying liver disease was caused by hepatitis C (2 patients), primary biliary cirrhosis (1 patient), cryptogenic cirrhosis (1 patient), alcohol (2 patients), and hepatitis C with alcohol (2 patients). Six out of eight patients required preoperative oxygen support. Severe hypoxemia was present in seven patients (Pa(O2) 51.5 +/- 8.2 mm Hg). Three patients had complicating pulmonary hypertension. All patients exhibited a severely reduced D(L)CO (44.6 +/- 12.2% of predicted value). Six patients were transplanted, with five requiring oxygen support at the time of discharge. Resolution of oxygen dependency occurred in all patients but was delayed in the two patients exhibiting complicating pulmonary hypertension (288.5 +/- 37.4 v 53.5 +/- 35.7 days). All patients exhibited O2 saturations greater than 98% on room air. Currently, three patients are alive and off oxygen. The current report documents successful resolution of hypoxemia after LT in this pilot cohort. This supports the newly implemented United Network for Organ Sharing (UNOS) criteria, that LT for HPS may be extended to include patients with Pa(O2) < 60 mm Hg.