Metabolic issues in liver transplantation

Elevated effluent potassium concentrations predict the development of postreperfusion hyperkalemia in deceased liver transplantation: a retrospective cohort study

BACKGROUND

Postreperfusion hyperkalemia (PRHK) has garnered increasing attention in regard to deceased liver transplantation (LT), especially for LT using the expanded criteria donor grafts. However, the impact of the effluent potassium (eK⁺) concentration on PRHK has been largely overlooked. We evaluated whether elevated eK⁺ concentrations are associated with PRHK in deceased LT.

METHODS

In this single-institution, retrospective cohort study, we included all adults who underwent deceased LT with intraoperative eK⁺ concentration monitoring between November 2016 and December 2018. The eK⁺ concentrations were obtained from the effluent samples collected following a standard portal vein flush. PRHK was defined as any serum potassium (sK⁺) level of > 5.5 mmol/L following reperfusion. Logistic regression was performed to identify predictors for PRHK, and linear regression was used to examine predictors of the maximum percentage increase in the sK⁺ level following reperfusion.

RESULTS

Of the 86 patients who met the inclusion criteria, 54 (62.8%) developed PRHK. Independent predictors for PRHK included greater graft weight (OR 1.283 [95% CI 1.029-1.599] per 100 g, P = 0.027), an elevated eK⁺ concentration (OR 1.291 [95% CI 1.068-1.561] per mol/L, P = 0.008), and a higher sK⁺ level before reperfusion (OR 4.459 [95% CI 1.543-12.884] per mol/L, P = 0.006). An eK⁺ concentration of more than 6.9 mmol/L had a sensitivity of 59.26% and a specificity of 78.12% for predicting PRHK (area under the receiver operating characteristic curve, 0.694). Multiple linear regression analyses indicated that the eK⁺ and sK⁺ levels before reperfusion were significant predictors of the maximum percentage increase in the sK⁺ level following reperfusion. In addition, PRHK was associated with an increased risk of postreperfusion significant arrhythmias, severe postreperfusion syndrome, and postoperative early allograft dysfunction.

CONCLUSIONS

This study shows that the eK⁺ concentration could predict the risk of PRHK in deceased LT. Further prospective studies are warranted to clarify these associations.

Changes in Blood Potassium after Reperfusion during Living-Donor Liver Transplantation: An Exploratory Study

The incidence of hyperkalemia (>5.5 mEq/L) or high blood potassium (5–5.5 mEq/L) during living-donor liver transplantation (LDLT) is reported to be more than 10%. It occurs more frequently in the early post-reperfusion period and is a major cause of post-reperfusion arrhythmia and cardiac arrest. Unlike deceased-donor liver transplantation, the pattern of blood potassium changes immediately after reperfusion has not been described in LDLT. From January 2021 to March 2021, fifteen consecutive patients were enrolled. Baseline blood potassium was measured from blood samples obtained 10-min (T_-10) and immediately before (T₀) reperfusion. During the first 5 min after reperfusion, blood potassium measurements were conducted every one minute (T₁–T₅). The blood potassium levels at T_-10 and T₀ were 3.8 ± 0.4 and 3.9 ± 0.4 mEq/L, respectively. After reperfusion, mean increases (95% CI) in blood potassium from T_-10 and T₀ were 0.5 (0.4–0.6) and 0.4 (0.3–0.5) mEq/L, respectively. Blood potassium peaked at T₁, returned to baseline at T₃, and fell below the baseline at T₅. Peak blood potassium after reperfusion showed strong correlations with blood potassium measured at T_-10 (p < 0.001) and T₀ (p < 0.0001). These findings can support the establishment of future research plans and perioperative management of blood potassium in LDLT.

Long-term impact of dialysis-requiring AKI during the perioperative period of liver transplantation on postdischarge outcomes

BACKGROUND

Patients undergoing liver transplantation (LT) are prone to dialysis-requiring acute kidney injury (AKI-D). However, long-term prognoses among them need further investigation, as overall survival after LT is improving.

METHODS

A nationwide, population-based cohort study was conducted using the data of Korean National Health Insurance System between 2006 and 2015. The patients who received dialysis during the perioperative period of LT were in the AKI-D group, and the control group included those who did not undergo dialysis.

RESULTS

Among the 6879 patients who underwent LT, 968 were in the AKI-D group. All-cause mortality [adjusted hazard ratio (HR): 1.52 (1.26-1.83), P < 0.001], end-stage renal disease (ESRD) progression [adjusted HR: 2.93 (2.34-3.66), P < 0.001], and ICU readmission [adjusted HR: 1.70 (1.44-2.01), P < 0.001] within and after 90 days from discharge were increased in the AKI-D group. When analyzed among those who recovered from dialysis at discharge, overall outcomes were similar to those of the AKI-D group, except the long-term mortality.

CONCLUSIONS

AKI-D during the perioperative period of LT was associated with worse mortality, ESRD progression, and ICU readmission risk. The results of renal-recovered patients could indicate clinicians that achievement of dialysis independence is important to gain favorable long-term postdischarge survival.

Opposite acute potassium and sodium shifts during transplantation of hypothermic machine perfused donor livers

Liver transplantation is frequently associated with hyperkalemia, especially after graft reperfusion. Dual hypothermic oxygenated machine perfusion (DHOPE) reduces ischemia/reperfusion injury and improves graft function, compared to conventional static cold storage (SCS). We examined the effect of DHOPE on ex situ and in vivo shifts of potassium and sodium. Potassium and sodium shifts were derived from balance measurements in a preclinical study of livers that underwent DHOPE (n = 6) or SCS alone (n = 9), followed by ex situ normothermic reperfusion. Similar measurements were performed in a clinical study of DHOPE-preserved livers (n = 10) and control livers that were transplanted after SCS only (n = 9). During DHOPE, preclinical and clinical livers released a mean of 17 ± 2 and 34 ± 6 mmol potassium and took up 25 ± 9 and 24 ± 14 mmol sodium, respectively. After subsequent normothermic reperfusion, DHOPE-preserved livers took up a mean of 19 ± 3 mmol potassium, while controls released 8 ± 5 mmol potassium. During liver transplantation, blood potassium levels decreased upon reperfusion of DHOPE-preserved livers while levels increased after reperfusion of SCS-preserved liver, delta potassium levels were -0.77 ± 0.20 vs. +0.64 ± 0.37 mmol/L, respectively (P = .002). While hyperkalemia is generally anticipated during transplantation of SCS-preserved livers, reperfusion of hypothermic machine perfused livers can lead to decreased blood potassium or even hypokalemia in the recipient.

Portland Intensive Insulin Therapy During Living Donor Liver Transplantation: Association with Postreperfusion Hyperglycemia and Clinical Outcomes

Many liver transplant recipients experience intraoperative hyperglycemia after graft reperfusion. Accordingly, we introduced the Portland intensive insulin therapy (PoIIT) in our practice to better control blood glucose concentration (BGC). We evaluated the effects of PoIIT by comparing with our conventional insulin therapy (CoIT). Of 128 patients who underwent living donor liver transplantation (LDLT) during the phaseout period of CoIT, 89 were treated with the PoIIT and 39 were treated with CoIT. The primary outcome was hyperglycemia (BGC > 180 mg/dL) during the intraoperative postreperfusion phase. The secondary outcomes were postoperative complications such as infection. The incidence of hyperglycemia (22.5% vs. 53.8%, p = 0.001) and prolonged hyperglycemia for >2 hours (7.9% vs. 30.8%, p = 0.002) was significantly lower in PoIIT group than in CoIT group. A mixed linear model further demonstrated that repeatedly measured BGCs were lower in PoIIT group (p < 0.001). The use of PoIIT was significantly associated with decreases in major infections (OR = 0.23 [0.06-0.85], p = 0.028), prolonged mechanical ventilation (OR = 0.29 [0.09-0.89], p = 0.031), and biliary stricture (OR = 0.23 [0.07-0.78], p = 0.018) after adjustments for age, sex, and diabetes mellitus. In conclusion, the PoIIT is effective for maintaining BGC and preventing hyperglycemia during the intraoperative postreperfusion phase of living donor liver transplantation with potential clinical benefits.

Intraoperative management of liver transplant recipients having severe renal dysfunction: results of 42 cases

Purpose

Whereas continuous renal replacement therapy (CRRT) has been utilized during liver transplantation (LT), there was a lack of evidence to support this practice. We investigated the adverse events at the perioperative periods in recipients of LT who received preoperative CRRT without intraoperative CRRT.

Methods

We retrospectively reviewed medical records of adult patients (age ≥ 18 years) who received LT between December 2009 and May 2015. Perioperative data were collected from the recipients, who received preoperative CRRT until immediately before LT, because of refractory renal dysfunction.

Results

Of 706 recipients, 42 recipients received preoperative CRRT. The mean (standard deviation) Model for end-stage liver disease score were 49.6 (13.4). Twenty-six point two percent (26.2%) of recipients experienced the serum potassium > 4.5 mEq/L before reperfusion and treated with regular insulin. Thirty-eight point one percent (38.1%) of recipients were managed with sodium bicarbonate because of acidosis (base excess < −10 mEq/L throughout LT). All patients finished their operations without medically uncontrolled complications such as severe hyperkalemia (serum potassium > 5.5 mEq/L), refractory acidosis, or critical arrhythmias. Mortality was 19% at 30 day and 33.3% at 1 year.

Conclusion

Although intraoperative CRRT was not used in recipients with severe preoperative renal dysfunction, LT was safely performed. Our experience raises a question about the need for intraoperative CRRT.

PREVALENCE AND RISK FACTORS OF HYPERKALEMIA AFTER LIVER TRANSPLANTATION

BACKGROUND

There is a lack of data regarding hyperkalemia after liver transplantation.

AIM

To evaluate the prevalence of hyperkalemia after liver transplantation and its associated factors.

METHODS

This retrospective cohort study evaluated 147 consecutive post-transplant patients who had at least one year of outpatient medical follow up. The data collection included gender, age, potassium values, urea, creatinine, sodium and medication use at 1, 6 and 12 months after. Hyperkalemia was defined as serum potassium concentrations higher than 5.5 mEq/l.

RESULTS

Hiperkalemia was observed in 18.4%, 17.0% and 6.1% of patients 1, 6 and 12 months after tranplantation, respectively. Older age (p=0.021), low creatinine clearance (p=0.007), increased urea (p=0.010) and hypernatremia (p=0.014) were factors associated with hyperkalemia, as well as the dose of prednisone at six months (p=0.014).

CONCLUSION

Hyperkalemia was prevalent in less than 20% of patients in the 1st month after liver transplantation and decreased over time. Considering that hyperkalemia does not affect all patients, attention should be paid to the routine potassium intake recommendations, and treatment should be individualized.

Electrolyte and Acid-Base Disturbances in End-Stage Liver Disease: A Physiopathological Approach

Electrolyte and acid-base disturbances are frequent in patients with end-stage liver disease; the underlying physiopathological mechanisms are often complex and represent a diagnostic and therapeutic challenge to the physician. Usually, these disorders do not develop in compensated cirrhotic patients, but with the onset of the classic complications of cirrhosis such as ascites, renal failure, spontaneous bacterial peritonitis and variceal bleeding, multiple electrolyte, and acid-base disturbances emerge. Hyponatremia parallels ascites formation and is a well-known trigger of hepatic encephalopathy; its management in this particular population poses a risky challenge due to the high susceptibility of cirrhotic patients to osmotic demyelination. Hypokalemia is common in the setting of cirrhosis: multiple potassium wasting mechanisms both inherent to the disease and resulting from its management make these patients particularly susceptible to potassium depletion even in the setting of normokalemia. Acid-base disturbances range from classical respiratory alkalosis to high anion gap metabolic acidosis, almost comprising the full acid-base spectrum. Because most electrolyte and acid-base disturbances are managed in terms of their underlying trigger factors, a systematic physiopathological approach to their diagnosis and treatment is required.

Association Between Perioperative Hyperglycemia or Glucose Variability and Postoperative Acute Kidney Injury After Liver Transplantation: A Retrospective Observational Study

BACKGROUND

Glucose control can be difficult in the intraoperative and immediate postoperative period of liver transplantation. Hyperglycemia and glucose variability have been associated with acute kidney injury (AKI) in critically ill patients. We performed a retrospective study to test the hypothesis that perioperative glucose levels represented by time-weighted average glucose levels and glucose variability are independently associated with the incidence of postoperative AKI in patients undergoing liver transplantation.

METHODS

On the basis of blood glucose levels during liver transplantation and the initial 48 hours postoperatively, adult liver transplant recipients were classified into 4 groups according to their time-weighted average glucose: normoglycemia (80-200 mg/dL), mild hyperglycemia (200-250 mg/dL), moderate hyperglycemia (250-300 mg/dL), and severe hyperglycemia (>300 mg/dL) group. Patients were also classified into quartiles depending on their glucose variability, defined as the standard deviation of glucose measurements. The primary outcome was postoperative AKI.

RESULTS

AKI after liver transplantation was more common in the patients with greater perioperative glucose variability (first versus third quartile; OR, 2.47 [95%CI, 1.22-5.00], P = .012; first versus fourth quartile; OR, 2.16 [95% CI, 1.05-4.42], P = .035).

CONCLUSIONS

Our study suggests that increased perioperative glucose variability, but not hyperglycemia, is independently associated with increased risk of postoperative AKI in liver transplantation recipients.

Emergent laparotomy and temporary abdominal closure for the cirrhotic patient

BACKGROUND

Temporary abdominal closure (TAC) may be performed for cirrhotic patients undergoing emergent laparotomy. The effects of cirrhosis on physiologic parameters, resuscitation requirements, and outcomes following TAC are unknown. We hypothesized that cirrhotic TAC patients would have different resuscitation requirements and worse outcomes than noncirrhotic patients.

METHODS

We performed a 3-year retrospective cohort analysis of 231 patients managed with TAC following emergent laparotomy for sepsis, trauma, or abdominal compartment syndrome. All patients were initially managed with negative pressure wound therapy (NPWT) TAC with intention for planned relaparotomy and sequential abdominal closure attempts at 24- to 48-h intervals.

RESULTS

At presentation, cirrhotic patients had higher incidence of acidosis (33% versus 17%) and coagulopathy (87% versus 54%) than noncirrhotic patients. Forty-eight hours after presentation, cirrhotic patients had a persistently higher incidence of coagulopathy (77% versus 44%) despite receiving more fresh frozen plasma (10.8 units versus 4.4 units). Cirrhotic patients had higher NPWT output (4427 mL versus 2375 mL) and developed higher vasopressor infusion rates (57% versus 29%). Cirrhotic patients had fewer intensive care unit-free days (2.3 versus 7.6 days) and higher rates of multiple organ failure (64% versus 34%), in-hospital mortality (67% versus 21%), and long-term mortality (80% versus 34%) than noncirrhotic patients.

CONCLUSIONS

Cirrhotic patients managed with TAC are susceptible to early acidosis, persistent coagulopathy, large NPWT fluid losses, prolonged vasopressor requirements, multiple organ failure, and early mortality. Future research should seek to determine whether TAC provides an advantage over primary fascial closure for cirrhotic patients undergoing emergency laparotomy.

Postreperfusion hyperkalemia in liver transplantation using donation after cardiac death grafts with pathological changes

BACKGROUND

With the increasing use of donation after cardiac death (DCD), especially of the graft liver with steatosis or other pathological changes, the frequency of postreperfusion hyperkalemia in liver transplantation has increased significantly. The present study aimed to determine the factors associated with developing postreperfusion hyperkalemia in liver transplantation from DCD.

METHODS

One hundred thirty-one consecutive adult patients who underwent orthotopic liver transplantation from DCD were retrospectively studied. Based on serum potassium within 5 minutes after reperfusion, recipients were divided into two groups: hyperkalemia and normokalemia. According to preoperative biopsy results, the DCD graft livers were classified into five categories. Univariate analysis was performed using Chi-square test to identify variables that were significantly different between two groups. Multivariate logistic regression was used to confirm the risk factors of developing hyperkalemia and postreperfusion syndrome. Correlation analysis was used to identify the relationship between the serum concentration of potassium within 5 minutes after reperfusion and the difference in mean arterial pressure values before and within 5 minutes after reperfusion.

RESULTS

Twenty-two of 131 liver recipients had hyperkalemia episodes within 5 minutes after reperfusion. The rate of hyperkalemia was significantly higher in recipients of macrosteatotic DCD graft liver (78.6%, P<0.001) than that in recipients of non-macrosteatotic DCD graft liver. The odds ratio of developing postreperfusion hyperkalemia in recipients of macrosteatotic DCD graft liver was 51.3 (P<0.001). Macrosteatosis in the DCD graft liver was an independent risk factor of developing hyperkalemia within 5 minutes after reperfusion. The highest rate of postreperfusion syndrome also occurred in the recipients with macrosteatotic DCD graft liver (71.4%, P<0.001). A strong relationship existed between the serum potassium within 5 minutes after reperfusion and the difference in mean arterial pressure values before and within 5 minutes after reperfusion in macrosteatotic DCD graft liver recipients.

CONCLUSION

Macrosteatosis in the DCD graft liver was an independent risk factor of developing hyperkalemia and postreperfusion syndrome in the recipients.

Predictive roles of intraoperative blood glucose for post-transplant outcomes in liver transplantation

Diabetogenic traits in patients undergoing liver transplantation (LT) are exacerbated intraoperatively by exogenous causes, such as surgical stress, steroids, blood transfusions, and catecholamines, which lead to intraoperative hyperglycemia. In contrast to the strict glucose control performed in the intensive care unit, no systematic protocol has been developed for glucose management during LT. Intraoperative blood glucose concentrations typically exceed 200 mg/dL in LT, and extreme hyperglycemia (> 300 mg/dL) is common during the neohepatic phase. Only a few retrospective studies have examined the relationship between intraoperative hyperglycemia and post-transplant complications, with reports of infectious complications or mortality. However, no prospective studies have been conducted regarding the influence of intraoperative hyperglycemia in LT on post-transplant outcome. In addition to absolute blood glucose values, the temporal patterns in blood glucose levels during LT may serve as prognostic features. Persistent neohepatic hyperglycemia (without a decline) throughout LT is a useful indicator of early graft dysfunction. Moreover, intraoperative variability in glucose levels may predict the need for reoperation for hemorrhage after LT. Thus, there is an urgent need for guidelines for glucose control in these patients, as well as prospective studies on the impact of glucose control on various post-transplant complications. This report highlights some of the recent studies related to perioperative blood glucose management focused on LT and liver disease.

Blood glucose regulation during living-donor liver transplant surgery

OBJECTIVES

The goal of this study was to compare the effects of 2 different regimens on blood glucose levels of living-donor liver transplant.

MATERIALS AND METHODS

The study participants were randomly allocated to the dextrose in water plus insulin infusion group (group 1, n = 60) or the dextrose in water infusion group (group 2, n = 60) using a sealed envelope technique. Blood glucose levels were measured 3 times during each phase. When the blood glucose level of a patient exceeded the target level, extra insulin was administered via a different intravenous route. The following patient and procedural characteristics were recorded: age, sex, height, weight, body mass index, end-stage liver disease, Model for End-Stage Liver Disease score, total anesthesia time, total surgical time, and number of patients who received an extra bolus of insulin. The following laboratory data were measured pre- and postoperatively: hemoglobin, hematocrit, platelet count, prothrombin time, international normalized ratio, potassium, creatinine, total bilirubin, and albumin.

RESULTS

No hypoglycemia was noted. The recipients exhibited statistically significant differences in blood glucose levels during the dissection and neohepatic phases. Blood glucose levels at every time point were significantly different compared with the first dissection time point in group 1. Excluding the first and second anhepatic time points, blood glucose levels were significantly different as compared with the first dissection time point in group 2 (P < .05).

CONCLUSIONS

We concluded that dextrose with water infusion alone may be more effective and result in safer blood glucose levels as compared with dextrose with water plus insulin infusion for living-donor liver transplant recipients. Exogenous continuous insulin administration may induce hyperglycemic attacks, especially during the neohepatic phase of living-donor liver transplant surgery. Further prospective studies that include homogeneous patient subgroups and diabetic recipients are needed to support the use of dextrose plus water infusion without insulin.

Analysis of predictors for lactate elimination after reperfusion in recipients of living-donor liver transplantation

BACKGROUND

Graft-recipient weight ratio (GRWR) is the only documented predictor that influences the lactate elimination after reperfusion in living-donor liver transplantation (LDLT). This study was performed to investigate the predictors of lactate elimination after reperfusion in recipients of adult LDLT.

METHODS

The medical records of 159 patients who underwent LDLT were analyzed. Lactate level (mmol/L) was measured from just before the initiation of surgery (P0) and 5, 60, and 120 minutes after reperfusion of graft (R0, R1, and R2, respectively). The change of lactate level after reperfusion was defined as difference between lactate level measured at R0 and R2. Patients were divided into accumulation and elimination groups. Donor and recipient factors were compared between the 2 groups.

RESULTS

Lactate accumulation occurred in 80 of 159 recipients (50.3%), and elimination occurred in 79 (49.7%). GRWR and Model for End-Stage Liver Disease (MELD) score were higher in the elimination group. Lactate at R0 was lower in the elimination group.

CONCLUSIONS

Higher GRWR and MELD score and lower lactate level immediate after reperfusion of graft were predictors of lactate elimination after reperfusion during adult LDLT.

Implications of Hyponatremia in Liver Transplantation

Although there are a limited number of quality studies, appropriate peri-operative management of serum electrolytes seems to reduce adverse outcomes in liver transplantation. Hyponatremia is defined as the presence of serum concentration of sodium equal ≤130 mmol/L and it is detected in approximately 20% of patients with end stage liver disease waiting for a liver transplant (LT). This paper will focus on the pathogenesis of dilutional hyponatremia and its significance in terms of both candidacy for LT and post-operative outcomes.

Intraoperative hemodialysis during liver transplantation: a decade of experience

Liver transplantation (LT) for patients with renal dysfunction is frequently complicated by major fluid shifts, acidosis, and electrolyte and coagulation abnormalities. Continuous renal replacement therapy (CRRT) has been previously shown to ameliorate these problems. We describe the safety and clinical outcomes of intraoperative hemodialysis (IOHD) during LT for a group of patients with high Model for End-Stage Liver Disease (MELD) scores. We performed a retrospective study at our institution of patients who underwent IOHD from 2002 to 2012. Seven hundred thirty-seven patients underwent transplantation, and 32% received IOHD. The mean calculated MELD score was 37, with 38% having a MELD score ≥ 40. Preoperatively, 61% were in the intensive care unit, 19% were mechanically ventilated, 43% required vasopressor support, and 80% were on some form of renal replacement therapy at the time of transplantation, the majority being on CRRT. Patients on average received 35 U of blood products and 4.8 L of crystalloids without significant changes in hemodynamics or electrolytes. The average urine output was 450 ml, and the average amount of fluid removal with dialysis was 1.8 L. The 90-day patient and dialysis-free survival rates were 90% and 99%, respectively. One-year patient survival rates based on the pretransplant renal replacement status and the MELD status were not statistically different. This is the first large study to demonstrate the safety and feasibility of IOHD in a cohort of critically ill patients with high MELD scores undergoing LT with good patient and renal outcomes.

Intraoperative calcium-related risk factors for biochemical acute pancreatitis after living-donor liver transplantation

Laboratory-based biochemical acute pancreatitis (BAP) is considered to be a benign but common complication after liver transplantation (LT), which to compensate for transfusion-related hypocalcemia, usually demands a large quantity of exogenous calcium which may be associated with pancreatic injury. We sought to investigate the relationship between intraoperative calcium-related factors and BAP occurrence after living-donor LT. Perioperative data, including intraoperative calcium chloride administration and serum calcium levels, were reviewed from 217 patients who underwent living-donor LT. Hyperamylasemia (≥ 458 U/L) was used to define posttransplantation BAP according to previous reports. Posttransplantation BAP was identified among 37 patients (17.3%), who showed a greater death rate than those in the non-BAP group (21.6% vs 8.6%; P = .013). Compared to with calcium-related parameters, the 2 groups showed differences in the amount of calcium chloride administered during the preanhepatic phase, the serum calcium surge during the initial 2 h after the liver graft reperfusion, the last serum calcium level, and the amount of transfused pack red blood cells (P < .05). However, after multivariate adjustment, only the amount of administered calcium chloride during the preanhepatic phase (odds ratios, 2.11-5.87, depending an amount) and the serum calcium surge during the initial 2 hours after liver graft reperfusion (odds ratio, 2.34) were selected as risk factors for posttransplantation BAP. The risk ratio of posttransplantation BAP increased in proportion to the administered amount of calcium chloride. In conclusion, limiting excessive calcium administration during the preanhepatic phase and close monitoring of the serum calcium surge after reperfusion may be required to prevent posttransplantation BAP in living-donor LT.

Extended criteria donor and severe intraoperative glucose variability: association with reoperation for hemorrhage in liver transplantation

Reoperations for hemorrhage following liver transplantation (OLT) are commonly associated with increased morbidity and mortality. We sought to determine the incidence and risk factors for reoperation for hemorrhage among adult liver transplantations. We retrospectively analyzed 668 patients transplanted between January 2004 and November 2007. Within 30 days following transplantation one hundred eleven patients (16.6%) underwent 156 reoperations for hemorrhage, averaging 1.4 reoperations per patient. More than half of the reoperations occurred during the first 2 postoperative days. One-third of patients required 2 or more reoperations. Multivariate logistic regression analysis showed 4 independent risk factors: grafts from donors with multiple extended criteria, severe intraoperative glucose variability, intraoperative use of vasopressors, and red blood cell transfusion requirement. In conclusion, we identified several independent risk factors for reoperation due to hemorrhage following OLT. Avoidance of severe intraoperative glucose variability and careful evaluation of the benefits and risks of utilizing extended criteria donors must be considered before transplantation.

Sodium, potassium and glucose management in organ transplantation

PURPOSE OF REVIEW

To present current knowledge about the metabolic management of patients undergoing solid organ transplantation, and potential organ donors.

RECENT FINDINGS

Appropriate management of electrolytes and glucose improves outcome after transplantation, although conflicting evidence exists. Patients with cirrhosis-induced hyponatremia can be successfully transplanted but are at increased risk of postoperative complications. A new class of drugs, the vaptans, that antagonizes arginine vasopressin may be an effective treatment for hyponatremia in transplant candidates. Recent literature has documented the implications, predictors and potential therapies for perioperative hyperkalemia in the transplant population. The debate over appropriate targets for serum glucose in perioperative and critically ill patients has been lively. The documented risk of hypoglycemia associated with 'intensive insulin therapy' has led to the adoption of more conservative glycemic targets. Studies of glycemic control in transplant recipients are limited.

SUMMARY

In patients undergoing solid organ transplants, sodium management should aim to minimize an acute change in sodium concentration. Vaptans may be of future use in optimizing patients with cirrhosis prior to transplantation. Pending further studies, a perioperative 'middle ground' target glucose of between 140 and 180 mg/dl seems reasonable at this time.

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.

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.