Intraoperative transfusion management, antifibrinolytic therapy, coagulation monitoring and the impact on short-term outcomes after liver transplantation-A systematic review of the literature and expert panel recommendations.

BACKGROUND: Liver transplantation (LT) is frequently complicated by coagulopathy associated with end-stage liver disease (ESLD), that is, often multifactorial. OBJECTIVES: The objective of this systematic review was to identify evidence based intraoperative transfusion and coagulation management strategies that improve immediate and short-term outcomes after LT. METHODS: PRISMA-guidelines and GRADE-approach were followed. Three subquestions were formulated. (Q); Q1: transfusion management; Q2: antifibrinolytic therapy; and Q3: coagulation monitoring. RESULTS: Sixteen studies were included for Q1, six for Q2, and 10 for Q3. Q1: PRBC and platelet transfusions were associated with higher mortality. The use of prothrombin complex concentrate (PCC) and fibrinogen concentrate (FC) were not associated with reductions in intraoperative transfusion or increased thrombotic events. The use of cell salvage was not associated with hepatocellular carcinoma (HCC) recurrence or mortality. Cell salvage and transfusion education significantly decreased blood product transfusions. Q2: Epsilon-aminocaproic acid (EACA) and tranexamic acid (TXA) were not associated with decreased blood product transfusion, improvements in patient or graft survival, or increases in thrombotic events. Q3: Viscoelastic testing (VET) was associated with decreased allogeneic blood product transfusion compared to conventional coagulation tests (CCT) and is likely to be cost-effective. Coagulation management guided by VET may be associated with increases in FC and PCC use. CONCLUSION: Q1: A specific blood product transfusion practice is not recommended (QOE; low | Recommendation; weak). Cell salvage and educational interventions are recommended (QOE: low | Grade of Recommendation: moderate). Q2: The routine use of antifibrinolytics is not recommended (QOE; low | Recommendation; weak). Q3: The use of VET is recommended (QOE; low-moderate | Recommendation; strong).

Exchange Autotransfusion for Rapid Correction of Hyperkalemia During Liver Transplantation: A Case Report.

A 46-year-old woman with alcoholic cirrhosis and hepatorenal syndrome requiring hemodialysis presented with hyperkalemia (5.5 mEq/L) immediately before liver transplantation. For correction of hyperkalemia, an exchange transfusion began by removing her blood into an autotransfusion system to wash out noncellular components while maintaining normovolemia. Additionally, she received washed homologous red blood cells, insulin, and glucose to minimize or reduce the degree of hyperkalemia. Serum potassium level decreased to 4.0 mEq/L within 3 hours and was 5.0 mEq/L 30 seconds after reperfusion of the grafted liver. Postreperfusion syndrome was not observed. In summary, exchange transfusion was used successfully for rapid correction of hyperkalemia, showing the value of its application in liver transplantation.

Noninvasive monitoring of cerebral perfusion pressure in patients with acute liver failure using transcranial doppler ultrasonography.

Elevated intracranial pressure (ICP) leads to loss of cerebral perfusion, cerebral herniation, and irreversible brain damage in patients with acute liver failure (ALF). Conventional techniques for monitoring ICP can be complicated by hemorrhage and infection. Transcranial doppler ultrasonography (TCD) is a noninvasive device which can continuously measure cerebral blood flow velocity, producing a velocity-time waveform that indirectly monitors changes in cerebral hemodynamics, including ICP. The primary goal of this study was to determine whether TCD waveform features could be used to differentiate ALF patients with respect to ICP or, equally important, cerebral perfusion pressure (CPP) levels. A retrospective study of 16 ALF subjects with simultaneous TCD, ICP, and CPP measurements yielded a total of 209 coupled ICP-CPP-TCD observations. The TCD waveforms were digitally scanned and seven points corresponding to a simplified linear waveform were identified. TCD waveform features including velocity, pulsatility index, resistive index, fraction of the cycle in systole, slopes, and angles associated with changes in the slope in each region, were calculated from the simplified waveform data. Paired ICP-TCD observations were divided into three groups (ICP < 20 mmHg, n = 102; 20 < or = ICP < 30 mmHg, n = 74; and ICP > or = 30 mmHg, n = 33). Paired CPP-TCD observations were also divided into three groups (CPP > or = 80 mmHg, n = 42; 80 > CPP > or = 60 mmHg, n = 111; and CPP < 60 mmHg, n = 56). Stepwise linear discriminant analysis was used to identify TCD waveform features that discriminate between ICP groups and CPP groups. Four primary features were found to discriminate between ICP groups: the blood velocity at the start of the Windkessel effect, the slope of the Windkessel upstroke, the angle between the end systolic downstroke and start diastolic upstroke, and the fraction of time spent in systole. Likewise, 4 features were found to discriminate between the CPP groups: the slope of the Windkessel upstroke, the slope of the Windkessel downstroke, the slope of the diastolic downstroke, and the angle between the end systolic downstroke and start diastolic upstroke. The TCD waveform captures the cerebral hemodynamic state and can be used to predict dynamic changes in ICP or CPP in patients with ALF. The mean TCD waveforms for corresponding, correctly classified ICP and CPP groups are remarkably similar. However, this approach to predicting intracranial hypertension and CPP needs to be further refined and developed before clinical application is feasible.

Acute hypotensive transfusion reaction during liver transplantation in a patient on angiotensin converting enzyme inhibitors from low aminopeptidase P activity.

Acute hypotensive transfusion reactions are newly characterized transfusion reactions in which hypotension is the prominent feature. The pathophysiology of acute hypotensive transfusion reactions is related to the bradykinin function and its metabolism. A liver transplant recipient on treatment with an angiotensin converting enzyme inhibitor developed sudden hypotension, that is, systolic pressure of 60 mm Hg, after receiving 200 mL of a blood product mixture without significant surgical blood loss. He responded to the resuscitation measure, although hypotension developed again after a challenge transfusion of 200 mL of the blood mixture. A severe hypotensive reaction to the blood transfusion and diffuse bleeding from the dissection surfaces forced the transplantation to be aborted after the common bile duct had been divided. We hypothesized that the patient had an acute hypotensive transfusion reaction due to disordered bradykinin metabolism. Analysis of his blood showed low levels of both angiotensin converting enzyme and aminopeptidase P enzyme activity, confirming that the patient experienced an acute hypotensive transfusion reaction that was due to the use of the angiotensin converting enzyme inhibitor and was precipitated by an abnormality in the metabolic enzyme pathway. It is recommended to discontinue angiotensin converting enzyme inhibitors and switch to a different class of antihypertensive medications for patients with a high Model for End-Stage Liver Disease score on the waiting list for liver transplantation.

Anti-IL2 induction in liver transplantation with 93% rejection-free patient and graft survival at 18 months.

BACKGROUND: Induction with the use of monoclonal antibodies targeting the alpha-chain (CD25) of the high-affinity IL2 receptor may avoid many of the adverse events associated with polyclonal antibodies and significantly impact on rejection-free long-term survival in orthotopic liver transplantation (OLT). METHODS: Forty-two consecutive deceased donor primary OLT were retrospectively analyzed. All patients received two 20-mg doses of basiliximab (days 0 and 4 after OLT) followed by tacrolimus (0.15 mg/kg/day; 10-15 ng/mL target trough levels), and steroids (methylprednisolone 1 g intraoperatively followed by tapering doses). Mycophenolate mofetil (MMF) 1 g every 12 h was added to the drug combination as needed. The mean follow-up period was 19.3 months (range: 4.8-35.9 months). RESULTS: The average Model for End-Stage Liver Disease score was 26 (range: 15-40). A total of 39 patients (93%) remained rejection-free during follow-up with an actuarial rejection-free probability of 95% within 3 months. The actuarial patient and graft survival rate (Kaplan-Meier estimated) at 2 years was 93%. Twenty-five patients (60%) were completely off steroids within 3 months post-OLT (mean: 51.1 days, range: 10-90 days). By the 10th month post-OLT, 30/39 (77%) of the patients were completely off steroids. At last follow-up, 30/39 (77%) are on tacrolimus monotherapy with an average dose of 4 mg per day. Six patients (15%) are on double therapy, receiving a combination of tacrolimus and prednisone (two patients) or tacrolimus and MMF (two patients) or tacrolimus and mycophenolic acid (two patients). Only three patients (8%) are receiving triple therapy at last follow-up. Nine patients (21%) experienced at least one episode of infection. Only six (26%) of a total of 23 hepatitis C virus (HCV) recipients developed histology-proven HCV recurrence, with a mean onset of recurrence post-OLT of 3.2 months (range: 1.3-6.3 months). Of these six patients, two are presently undergoing treatment with interferon and ribavirin, one was treated and became HCV RNA negative, one was not treated, one declined treatment, and two died of HCV recurrence. None of the 42 study patients developed cytomegalovirus infection or posttransplant lymphoproliferative disease. CONCLUSIONS: These preliminary data suggest that basiliximab, given in combination with a tacrolimus-based immunosuppressive regimen, is safe and associated with a low incidence of acute rejection and excellent short-term rejection-free graft and patient survival rate after OLT.

Cerebral hemodynamic and metabolic profiles in fulminant hepatic failure: relationship to outcome.

The purpose of this retrospective study was to examine the potential role of cerebral hemodynamic and metabolic factors in the outcome of patients with fulminant hepatic failure (FHF). Based on the literature, a hypothetical model was proposed in which physiologic changes progress sequentially in five phases, as defined by intracranial pressure (ICP) and cerebral blood flow (CBF) measurements. Seventy-six cerebral physiologic profiles were obtained in 26 patients (2 to 5 studies each) within 6 days of FHF diagnosis. ICP was continuously measured by an extradural fiber optic monitor. Global CBF estimates were obtained by xenon clearance techniques. Jugular venous and peripheral artery catheters permitted calculation of cerebral arteriovenous oxygen differences (AVDO2), from which cerebral metabolic rate for oxygen (CMRO2) was derived. A depressed CMRO2 was found in all patients. There was no evidence of cerebral ischemia as indicated by elevated AVDO2s. Instead, over 65% of the patients revealed cerebral hyperemia. Eight of the 26 patients underwent orthotopic liver transplantation-all recovered neurologically, including 6 with elevated ICPs. Of the 18 patients receiving medical treatment only, all 7 with increased ICP died in contrast to 9 survivors whose ICP remained normal (P < 0.004). Hyperemia, per se, was not related to outcome, although it occurred more frequently at the time of ICP elevations. Six patients were studied during brain death. All 6 revealed malignant intracranial hypertension, preceded by hyperemia. In conclusion, the above findings are consistent with the hypothetical model proposed. Prospective longitudinal studies are recommended to determine the precise evolution of the pathophysiologic changes.

Evidence for hyperacute rejection of human liver grafts: The case of the canary kidneys.

Sequential liver and kidney transplantation from the same donor was performed in 2 patients. The kidney in Patient 1, which was transplanted after the liver, was hyperacutely rejected and removed 6 hours later. The first liver as well as another liver transplanted 3 days later developed widespread hemorrhagic necrosis. Although the cytotoxic crossmatch of preoperative recipient serum with both donors was negative, patchy widespread IgM and C(1q) deposits were found in all 3 organs. In Patient 2, who had a strongly positive cytotoxic crossmatch with his donor, the liver suffered a massive but reversible injury, while the kidney never functioned. Both patients developed a coagulopathy a few minutes after liver revascularization. The kidneys in these cases had served like the canaries which miners once used to detect a hostile environment and their presence made more understandable how an indolent version of hyperacute rejection of the liver can take place.