Glycemic control and organ transplantation

Optimization of physiology in organ donors in the intensive care unit - what you need to know

ABSTRACT

Optimizing the physiology of organ donors is a critical component of preserving the option for organ donation and addressing the shortage of organs available for transplantation. In this article, we review common physiologic alterations seen in organ donors with a focus on brain-dead organ donors. These physiologic alterations and recommended interventions to optimize the physiology of the brain-dead organ donor are discussed by organ system, providing a framework for trauma surgeons and intensivists involved in the care of organ donors.

High-resolution magic angle spinning nuclear magnetic resonance of donor pancreatic tissue may predict islet viability prior to isolation

For patients with type 1 diabetes mellitus complicated by severe hypoglycemia, clinical islet transplantation is an efficacious alternative to whole pancreas transplantation. While islet transplantation has improved over the last few years, there remain questions regarding its cost-effectiveness and donor allosensitization, which is exacerbated when islets from more than one donor are required. Understanding the features of a pancreas that would provide viable islets prior to isolation may lead to development of an accurate assay that could identify suitable pancreases and provide significant cost savings to a clinical islet transplantation program. In this pilot study, solid-state high-resolution magic angle spinning (HRMAS) nuclear magnetic resonance (NMR) spectroscopy was used to assess samples of convenience of human pancreatic tissue taken prior to islet isolation both before and after incubation using the two-layer perfluorocarbon (PFC)/University of Wisconsin (UW) solution cold-storage method. We observed that, prior to incubation, human pancreatic tissue exhibited evidence of hypoxia with decreased peak integrals associated with glucose and increased peak integrals corresponding to lactate and free fatty acids. After incubation, we observed a reversal of the hypoxia-induced damage, as integrals corresponding to glucose increased, and those corresponding to lactate and free fatty acid resonances decreased. Interestingly, a significant correlation between the ratio of the glucose integral (at 3.0-4.5 ppm) to the sum of the fatty acid (at 0.9 ppm) and lactate + fatty acid (at 1.3 ppm) integrals and glucose responsiveness, a measure of islet viability, of the isolated islets, was observed after incubation in PFC/UW solution for pancreases that responded to PFC/UW solution incubation (p = 0.02). Notably, pancreases with little or no change in the integral ratio after PFC/UW solution incubation had poor recovery. These results suggest that tissue recovery is a key feature for determining islet cell viability, and further that HRMAS NMR may be a practical method to quickly assess human donor pancreatic tissue prior to islet isolation for clinical transplantation.

Better liver transplant outcomes by donor interventions?

PURPOSE OF REVIEW

Donor risk factors and events surrounding donation impact the quantity and quality of grafts generated to meet liver transplant waitlist demands. Donor interventions represent an opportunity to mitigate injury and risk factors within donors themselves. The purpose of this review is to describe issues to address among donation after brain death, donation after circulatory determination of death, and living donors directly, for the sake of optimizing relevant outcomes among donors and recipients.

RECENT FINDINGS

Studies on donor management practices and high-level evidence supporting specific interventions are scarce. Nonetheless, for donation after brain death (DBD), critical care principles are employed to correct cardiocirculatory compromise, impaired tissue oxygenation and perfusion, and neurohormonal deficits. As well, certain treatments as well as marginally prolonging duration of brain death among otherwise stable donors may help improve posttransplant outcomes. In donation after circulatory determination of death (DCD), interventions are performed to limit warm ischemia and reverse its adverse effects. Finally, dietary and exercise programs have improved donation outcomes for both standard as well as overweight living donor (LD) candidates, while minimally invasive surgical techniques may offer improved outcomes among LD themselves.

SUMMARY

Donor interventions represent means to improve liver transplant yield and outcomes of liver donors and grafts.

Bolus versus continuous insulin infusion in immediate postoperative blood glucose control in liver transplantation: pragmatic clinical trial

Objective:

To analyze the effectiveness and safety of two insulin therapy techniques (continuous and intermittent infusion) in the blood glucose control of people who have undergone liver transplantation, in the immediate postoperative period.

Methods:

The study was a prospective, open, pragmatic clinical trial with 42 participants, divided into two groups of 21 patients each, in the immediate postoperative period following liver transplantation. Participants in the Experimental Group and Control Group received continuous infusion and bolus insulin, respectively, starting at capillary blood glucose ≥150mg/dL.

Results:

There were no statistically significant differences in the blood glucose reduction time to reach the target range between the Experimental Group and Control Group in the transplanted patients (p=0.919). No statistically significant differences regarding the presence of low blood glucose (p=0.500) and in the initial blood glucose value (p=0.345) were found. The study identified the final blood glucose value in postoperative intensive care unit lower and statistically significant in the continuous infusion pump group in relation to the Bolus Group (p<0.001). Additionally, the variation of blood glucose reduction was higher and statistically significant in the continuous method group (p<0.05).

Conclusion:

The continuous infusion method was more effective in the blood glucose control of patients in the postoperative period following liver transplantation.

Brazilian Registry of Clinical Trials:

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Femoral Neck Fracture in a Hemodialysis Patient after Liver Transplantation: A Case Report

Background

Surgical treatment of femoral neck fractures is usually performed as an urgent procedure so that restoration of the ability to stand and walk can be achieved as quickly as possible. However, orthopedic surgeons need to be aware of undertreated or untreated diseases in their patients. Organ transplant recipients require immunosuppressive agents and steroids postoperatively. Hemodialysis patients also exhibit immunological deterioration and are included among immunocompromised patients. We report a case in which conservative treatment was chosen for a hepatic transplant recipient on hemodialysis who suffered a femoral neck fracture because signs of inflammation of unknown etiology were intermittently seen.

Case

The patient was a 70-year-old man who had undergone liver transplantation from a living donor as treatment for hepatocellular cancer and hepatic failure with cirrhosis. Dialysis for end-stage renal failure was initiated at approximately 1 year postoperatively. Cyclosporine was administered as an immunosuppressive agent. The patient subsequently fell off a bicycle and was unable to walk because of right hip pain. He was brought to our hospital by ambulance, and a right hip radiograph revealed a femoral neck fracture. His white blood cell count and C-reactive protein levels were intermittently elevated with unknown etiology. Conservative treatment was finally adopted, although a bipolar hip arthroplasty was planned. At 5 months after the injury, the patient was able to walk alone in a stable manner using a pair of crutches and was discharged.

Discussion

Conservative treatment for a femoral neck fracture, which generally requires surgery, may be acceptable in organ transplant recipients on hemodialysis.

Optimisation of the organ donor and effects on transplanted organs: a narrative review on current practice and future directions

Mortality remains high for patients on the waiting list for organ transplantation. A marked imbalance between the number of available organs and recipients that need to be transplanted persists. Organs from deceased donors are often declined due to perceived and actual suboptimal quality. Adequate donor management offers an opportunity to reduce organ injury and maximise the number of organs than can be offered in order to respect the donor's altruistic gift. The cornerstones of management include: correction of hypovolaemia; maintenance of organ perfusion; prompt treatment of diabetes insipidus; corticosteroid therapy; and lung protective ventilation. The interventions used to deliver these goals are largely based on pathophysiological rationale or extrapolations from general critical care patients. There is currently insufficient high-quality evidence that has assessed whether any interventions in the donor after brain death may actually improve immediate post-transplant function and long-term graft survival or recipient survival after transplantation. Improvements in our understanding of the underlying mechanisms following brain death, in particular the role of immunological and metabolic changes in donors, offer promising future therapeutic opportunities to increase organ utilisation. Establishing a UK donor management research programme involves consideration of ethical, logistical and legal issues that will benefit transplanted patients while respecting the wishes of donors and their families.

Influence of Type 2 Diabetes Mellitus and Preoperative Hemoglobin A1c Levels on Outcomes of Liver Transplantation

Liver transplant centers often establish hemoglobin A1c (HbA1C) criteria for candidates with type 2 diabetes mellitus (T2DM) based on data from other surgical specialties showing worse outcomes in patients with poor glycemic control. However, because of the reduced reliability of HbA1C in cirrhosis, it is unclear whether pretransplant HbA1C values are predictive of postoperative complications in liver recipients. We retrospectively examined the association between preoperative HbA1C and postoperative outcomes in 173 consecutive patients who underwent liver transplantation at the University of Cincinnati Medical Center between August 2012 and March 2015. Demographic correlates of pretransplant HbA1C included age, T2DM, native Model for End‐Stage Liver Disease, hemoglobin, serum albumin, and nonalcoholic steatohepatitis as the indication for transplantation. No association was identified between pretransplant HbA1C and most outcome measures, including survival, length of stay, reoperation or readmission rates, rejection, bacteremia, and viremia. Significant correlates of HbA1C in liver recipients with diabetes were posttransplant insulin requirement and anastomotic biliary stricture formation. On multivariate analysis, HbA1C was the sole determinant of biliary strictures, with patients in the highest quartile (HbA1C >7.3%) exhibiting a 4‐fold increased risk. Correlation of HbA1C with morning blood glucose levels was much tighter after versus before transplantation. Conclusion: Preoperative HbA1C is predictive of anastomotic biliary stricture formation and the need for insulin following liver transplantation.

Management of the brain-dead donor in the ICU: general and specific therapy to improve transplantable organ quality

PURPOSE

To provide a practical overview of the management of the potential organ donor in the intensive care unit.

METHODS

Seven areas of donor management were considered for this review: hemodynamic management; fluids and electrolytes; respiratory management; endocrine management; temperature management; anaemia and coagulation; infection management. For each subchapter, a narrative review was conducted.

RESULTS AND CONCLUSIONS

Most elements in the current recommendations and guidelines are based on pathophysiological reasoning, epidemiological observations, or extrapolations from general ICU management strategies, and not on evidence from randomized controlled trials. The cardiorespiratory management of brain-dead donors is very similar to the management of critically ill patients, and the same applies to the management of anaemia and coagulation. Central diabetes insipidus is of particular concern, and should be diagnosed based on clinical criteria. Depending on the degree of vasopressor dependency, it can be treated with intermittent desmopressin or continuous vasopressin, intravenously. Temperature management of the donor is an area of uncertainty, but it appears reasonable to strive for a core temperature of > 35 °C. The indications and controversies regarding endocrine therapies, in particular thyroid hormone replacement therapy, and corticosteroid therapy, are discussed. The potential donor should be assessed clinically for infections, and screening tests for specific infections are an essential part of donor management. Although the rate of infection transmission from donor to receptor is low, certain infections are still a formal contraindication to organ donation. However, new antiviral drugs and strategies now allow organ donation from certain infected donors to be done safely.

Perioperative glucose management and outcomes in liver transplant recipients: A qualitative systematic review

AIM

To investigate the relationship between post-liver transplantation (LT) glycemic control and LT outcomes.

METHODS

A qualitative systematic review on relevant prospective interventions designed to control glucose levels including insulin protocols. Studies investigating an association between glycemic control and post-LT outcomes such as mortality, graft rejection, and infection rate were reviewed. PubMed, EMBASE, and other databases were searched through October 2016.

RESULTS

Three thousands, six hundreds and ninety-two patients from 14 studies were included. Higher mortality rate was seen when blood glucose (BG) ≥ 150 mg/dL (P = 0.05). BG ≥ 150 mg/dL also led to higher rates of infection. Higher rates of graft rejection were seen at BG > 200 mg/dL (P < 0.001). Mean BG ≥ 200 mg/dL was associated with more infections (P = 0.002). Nurse-initiated protocols and early screening strategies have shown a reduction in negative post-LT outcomes.

CONCLUSION

Hyperglycemia in the perioperative period is associated with poor post-LT outcomes. Only a few prospective studies have designed interventions aimed at managing post-LT hyperglycemia, post-transplant diabetes mellitus (PTDM) and their impact on post-LT outcomes.

Perioperative Care of the Liver Transplant Patient

With the evolution of surgical and anesthetic techniques, liver transplantation has become "routine," allowing for modifications of practice to decrease perioperative complications and costs. There is debate over the necessity for intensive care unit admission for patients with satisfactory preoperative status and a smooth intraoperative course. Postoperative care is made easier when the liver graft performs optimally. Assessment of graft function, vigilance for complications after the major surgical insult, and optimization of multiple systems affected by liver disease are essential aspects of postoperative care. The intensivist plays a vital role in an integrated multidisciplinary transplant team.

Glucose Metabolism and Associated Outcome After Pediatric Liver Transplantation

BACKGROUND

Despite hypoglycemia and hyperglycemia being frequently observed in the early postoperative phase, information on glucose metabolism after pediatric liver transplantation (pLT) is scarce.

METHODS

The goal of this retrospective single-center study, which included 46 patients who consecutively underwent 55 liver transplantations, was to gather data on glucose uptake, the prognostic relevance of hyperglycemia, and the safety of insulin administration in patients after pLT.

RESULTS

In this study population, glucose intake to keep blood sugar levels (BSLs) within the targeted range of 120 to 200 mg/dL (6.7-11.1 mmol/L) increased rapidly over the first few postoperative days and was significantly correlated with graft function. There was no association between a postoperative daily mean BSL >200 mg/dL and specific posttransplant complications (acute rejection, infection, need for retransplantation, and/or death). High postoperative mean 7-day BSLs were associated with poor glucose metabolism and an increase in morbidity and 6-month posttransplant mortality. Hypoglycemia was not observed under insulin administration.

CONCLUSIONS

With high BSLs being associated with poor glucose metabolism, it is likely that the critical illness itself, in addition to poor graft function, causes the increase in morbidity and mortality, with hyperglycemia serving as a marker.

Relationship Between Hyperglycemia and Heart Transplant Rejection

PURPOSE

Hyperglycemia increases risks of kidney and liver transplant rejection. To determine whether perioperative and subsequent glycemic control was associated with increased risk of heart transplant rejection over the year after transplantation, we performed a retrospective analysis of glycemic control and rejection rates in heart transplantation patients.

METHODS

Perioperative glucose levels were analyzed in 157 patients undergoing transplantation at Northwestern Memorial Hospital from June 2005 to December 2012 and compared in patients with and without rejection found on routine follow-up biopsy specimens.

RESULTS

Grade ≤1R rejection on biopsy was observed in 116 patients and grade ≥2R rejection (grade requiring increased anti-rejection treatment) in 41 patients. Although no significant differences in the preoperative fasting or inpatient mean glucose levels were found, the mean glucose levels from discharge to 1 year trended higher in those with grade ≥2R compared to grade ≤1R (128.8 ± 40.9 versus 142.2 ± 46.6 mg/dL, P = .084). In a multivariable logistic regression model, neither the lowest nor highest quartile of glucose levels had significantly different odds ratios (ORs) for the development of ≥2R compared to the middle 50% glucose levels. Older age (OR 0.96, P = .020) and higher body mass index levels (OR 0.86, P = .004) were significantly associated with lower odds of developing grade ≥2R.

CONCLUSIONS

Although the glucose trend regarding rejection was not statistically significant, we cannot exclude the possibility that much higher glucose levels would influence rejection rates.

Inhibition of Toll-like receptor 4 signaling ameliorates lung ischemia-reperfusion injury in acute hyperglycemic conditions

BACKGROUND

Recent lung transplantation studies have shown that peri-operative hyperglycemia is an important factor affecting recipient survival; however, its underlying mechanisms are not well understood. We hypothesized that acute hyperglycemia exacerbates lung ischemia-reperfusion injury (IRI) through up-regulation of Toll-like receptor 4 (TLR4) signaling pathways.

METHODS

C57BL/6Ncr mice were divided into 3 treatment groups: sham; IRI; and IRI under acute hyperglycemic conditions (IRI+HG). Mice in the IRI and IRI+HG groups were exposed to IRI via clamping the left hilum for 1 hour, followed by reperfusion for 2 hours. Acute hyperglycemia was established by glucose injection. The severity of lung injury and TLR4 signaling pathway activity were assessed. Further, we performed a pharmacologic blockade of TLR4 signaling to determine the effect of TLR4 signaling inhibition on lung injury.

RESULTS

Compared with normoglycemic mice, hyperglycemic mice had 2-fold higher blood glucose levels (p < 0.001). Pulmonary compliance was significantly lower, and airway resistance was significantly higher, in the IRI+HG group than in the IRI group (p < 0.05). Levels of inflammatory cytokines in bronchoalveolar lavage fluid were significantly higher in the IRI+HG group than in the IRI group. Correspondingly, TLR4 signaling pathways were up-regulated in the IRI+HG group. Moreover, pharmacologic inhibition of TLR4 signaling significantly decreased lung injury markers under hyperglycemic conditions.

CONCLUSIONS

Acute hyperglycemia exacerbated lung IRI and was associated with up-regulation of TLR4 signaling pathways. Pharmacologic inhibition of TLR4 signaling ameliorated lung IRI with acute hyperglycemia. Targeting TLR4 appears to be a promising approach to managing coexisting pathologies in lung transplant recipients.

Clinical Risk Scoring Models for Prediction of Acute Kidney Injury after Living Donor Liver Transplantation: A Retrospective Observational Study

Acute kidney injury (AKI) is a frequent complication of liver transplantation and is associated with increased mortality. We identified the incidence and modifiable risk factors for AKI after living-donor liver transplantation (LDLT) and constructed risk scoring models for AKI prediction. We retrospectively reviewed 538 cases of LDLT. Multivariate logistic regression analysis was used to evaluate risk factors for the prediction of AKI as defined by the RIFLE criteria (RIFLE = risk, injury, failure, loss, end stage). Three risk scoring models were developed in the retrospective cohort by including all variables that were significant in univariate analysis, or variables that were significant in multivariate analysis by backward or forward stepwise variable selection. The risk models were validated by way of cross-validation. The incidence of AKI was 27.3% (147/538) and 6.3% (34/538) required postoperative renal replacement therapy. Independent risk factors for AKI by multivariate analysis of forward stepwise variable selection included: body-mass index >27.5 kg/m2 [odds ratio (OR) 2.46, 95% confidence interval (CI) 1.32-4.55], serum albumin <3.5 mg/dl (OR 1.76, 95%CI 1.05-2.94), MELD (model for end-stage liver disease) score >20 (OR 2.01, 95%CI 1.17-3.44), operation time >600 min (OR 1.81, 95%CI 1.07-3.06), warm ischemic time >40 min (OR 2.61, 95%CI 1.55-4.38), postreperfusion syndrome (OR 2.96, 95%CI 1.55-4.38), mean blood glucose during the day of surgery >150 mg/dl (OR 1.66, 95%CI 1.01-2.70), cryoprecipitate > 6 units (OR 4.96, 95%CI 2.84-8.64), blood loss/body weight >60 ml/kg (OR 4.05, 95%CI 2.28-7.21), and calcineurin inhibitor use without combined mycophenolate mofetil (OR 1.87, 95%CI 1.14-3.06). Our risk models performed better than did a previously reported score by Utsumi et al. in our study cohort. Doses of calcineurin inhibitor should be reduced by combined use of mycophenolate mofetil to decrease postoperative AKI. Prospective randomized trials are required to address whether artificial modification of hypoalbuminemia, hyperglycemia and postreperfusion syndrome would decrease postoperative AKI in LDLT.

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.

Impact of preexisting diabetes mellitus on transplantation outcomes in hematopoietic stem cell transplantation

New onset diabetes mellitus is frequently observed following hematopoietic stem cell transplantation (HSCT) and is associated with adverse transplantation outcomes. However, the outcomes of patients with preexisting diabetes mellitus undergoing HSCT are largely unknown. We aimed to explore the impact of preexisting diabetes on transplantation outcomes in HSCT. In a retrospective study, medical charts of 34 HSCT recipients with diabetes mellitus undergoing allogeneic or autologous transplantation were reviewed and compared with 71 HSCT recipients without diabetes. Primary outcome was overall survival. Secondary outcomes included hematopoietic recovery, length of hospital stay, febrile neutropenia, acute and chronic graft-versus-host disease (GVHD), primary disease recurrence, and non-relapse mortality (NRM). On univariate analysis, there was no difference in transplantation outcomes in recipients with diabetes compared with recipients without diabetes. However, after adjusting for potential covariates, multivariate analysis demonstrated that having diabetes before HSCT significantly predicted outcome and decreased overall survival (hazard ratio 0.51, 95% confidence interval: 0.27-0.97, p value: 0.04). This study suggests that patients with diabetes mellitus undergoing allogeneic or autologous HSCT may have inferior survival rates and warrant further attention.

Application of a glycaemic control optimization programme in patients with stress hyperglycaemia

BACKGROUND

Stress-induced hyperglycaemia (SHG) can be observed in as high as 75% of critically ill patients, which can induce severe complications or adverse events. However, conventional intensive insulin therapy (CIIT) tends to induce hypoglycaemia and glucose variability.

AIMS

This study investigated the clinical effects of a blood glycaemic control optimization programme (BGCOP) in patients with stress hyperglycaemia post hepatobiliary or pancreatic surgery.

DESIGN

This study is a randomized, controlled, prospective clinical observation.

METHODS

Eighty-six patients with postoperative SHG were randomly divided into a control and experimental groups. Participants in the control group underwent CIIT, while participants in the experimental group underwent blood glycaemic control optimization programme (BGCOP). A range of 7·8-10·0 mmol/L was designated as the target range for effective control of blood sugar. The validity index, adverse events and complications were compared between two groups.

RESULTS

Compared to participants treated with CIIT, participants treated with BGCOP reached the target range of blood sugar levels more quickly (p = 0·000). The high glycaemic index (p = 0·000), incidence of hypoglycaemia (p = 0·011), and other adverse events as well as the incidence of abdominal infection (p = 0·026), incision infection (p = 0·044), and lung infection (p = 0·047) were significantly lower in participants who underwent the BGCOP than in patients treated with CIIT.

CONCLUSION

BGCOP can more effectively control blood sugar levels compared with CIIT in patients with SHG after hepatobiliary or pancreatic surgery.

RELEVANCE TO CLINICAL PRACTICE

This study provides a direction for blood glycaemic control in patients with stress hyperglycaemia post hepatobiliary or pancreatic surgery.

Erythropoietin protects myocardium against ischemia-reperfusion injury under moderate hyperglycemia

Erythropoietin (EPO), an essential hormone for erythropoiesis, provides protection against myocardial ischemia/reperfusion (I/R) injury. Hyperglycemia during acute myocardial infarction aggravates organ damage and attenuates the efficacies of various protective measures. This study aimed to investigate the protective role of EPO against myocardial I/R injury under a clinically relevant moderate hyperglycemic condition and its associated mechanisms. Eighty-two Sprague-Dawley rats were randomly assigned to six groups: normoglycemia-Sham, normoglycemia-I/R-control-saline (IRC), normoglycemia-I/R-EPO (IRE), hyperglycemia-Sham, hyperglycemia-IRC, and hyperglycemia-IRE. The rats received 1.2 g/kg dextrose or same volume of normal saline depending on the group. I/R was induced by a 30 min period of ischemia followed by reperfusion for 4 h. For 1 h before I/R injury, intravenous 4000 IU/kg of EPO was administered. EPO pretreatment significantly reduced the number of apoptotic cells and the infarct size compared with those of the control groups. EPO increased GATA-4 phosphorylation and acetylation against I/R in hyperglycemic myocardium. It also enhanced ERK induced GATA-4 post-translational modifications such as increased GATA-4 phosphorylation and acetylation, and decreased GATA-4 ubiquitination following hypoxia-reoxygenation in H9c2 cells in hyperglycemic medium. Increased GATA-4 stability by EPO diminished I/R-related down-regulation of Bcl-2 and reduction of caspase-3 activities in hyperglycemic myocardium. In conclusion, EPO pretreatment before I/R injury conveyed significant myocardial protection under moderate hyperglycemic condition through mechanisms involved in reduction of caspase-3 activity and up-regulation of Bcl-2 in association with enhanced ERK-induced GATA-4 stability.

Glucocorticoid-induced hyperglycemia

Corticosteroid-induced hyperglycemia is a common medical problem that can lead to frequent emergency room visits, hospital admissions and prolonged hospital stay, in addition to the well known morbidity associated with hyperglycemia. However, the diagnosis and treatment of corticosteroid-induced hyperglycemia is surprisingly undervalued by most professionals, probably because of the lack of quality studies to determine specific strategies of action. In the present review, we discuss the pathophysiology of corticosteroid-induced hyperglycemia, focusing on diverse patterns of hyperglycemia induced by the different formulations, and provide clues for diagnosis based on the duration of treatment and the administration schedule of corticosteroids. We propose a treatment strategy based on both the pathophysiology of the process and the mechanism of action of different corticosteroids, and take into account dosing and administration timing to predict the duration of therapy. Finally, we propose treatment goals that differ slightly between the transient and continuous use of corticosteroids based on evidence from clinical practice guidelines of diabetes care both in ambulatory and hospital settings.

Comparison of high- and low-dose corticosteroid regimens for organ donor management

PURPOSE

Corticosteroids are used to promote hemodynamic stability and reduce inflammatory organ injury after brain death. High-dose (HD) methylprednisolone has become the standard regimen based on comparisons to untreated/historical controls. However, this protocol may exacerbate hyperglycemia. Our objective was to compare a lower-dose (LD) steroid protocol (adequate for hemodynamic stabilization in adrenal insufficiency and sepsis) to the traditional HD regimen in the management of brain-dead organ donors.

METHODS

We evaluated 132 consecutive brain-dead donors managed before and after changing the steroid protocol from 15 mg/kg methylprednisolone (HD) to 300 mg hydrocortisone (LD). Primary outcome measures were glycemic control, oxygenation, hemodynamic stability, and organs transplanted.

RESULTS

Groups were balanced except for nonsignificantly higher baseline Pao(2) in the LD cohort. Final Pao(2) remained higher (394 mm Hg LD vs 333 mm Hg HD, P=.03); but improvement in oxygenation was comparable (+37 mm Hg LD vs +28 mm Hg HD, P=.43), as was the proportion able to come off vasopressor support (39% LD vs 47% HD, P=.38). Similar proportions of lungs (44% vs 33%) and hearts (31% vs 27%) were transplanted in both groups. After excluding diabetics, median glucose values at 4 hours (170 mmol/L vs 188 mmol/L, P=.06) and final insulin requirements (2.9 U/h vs 8.4 U/h, P=.01) were lower with LD steroids; and more patients were off insulin infusions (74% LD vs 53% HD, P=.02).

CONCLUSIONS

A lower-dose corticosteroid protocol did not result in worsened donor pulmonary or cardiac function, with comparable organs transplanted compared with the traditional HD regimen. Insulin requirements and glycemic control were improved. High-dose methylprednisolone may not be required to support brain-dead donors.

Safety and effectiveness of intensive insulin protocol use in post-operative liver transplant recipients

There is a paucity of data regarding the safety and utility of strict glycemic control in patients undergoing orthotopic liver transplantation (OLT). Although control of hyperglycemia may theoretically be beneficial, concerns exist regarding the effect of iatrogenic hypoglycemia on graft function. We performed a retrospective observational study evaluating the impact of the introduction of a nurse-initiated glycemic control protocol on OLT recipients cared for in a single intensive care unit (ICU). The medical records of 84 OLT recipients in 2003 (Preprotocol group) and 77 recipients in 2007 (Protocol group) were reviewed. Data regarding demographics, medical history, physiology, perioperative anesthesia and surgical events, ICU stay, graft function, and mortality were abstracted. Glucose values on admission to ICU, at 2, 6, 12, 18, and 24 hours after surgery, and at 4 am on the morning after OLT were recorded. Patients in the Protocol group achieved better and faster glycemic control. The odds ratio for severe hyperglycemia (glucose >250 mg/dL) in the Protocol group was 0.16 (95% confidence interval, 0.09-0.28). Hypoglycemia was not observed. The 1-year mortality was 5.3% in the Preprotocol and 6.0% in the Protocol group (P = .86). The rate of graft loss was low, and there was no difference in the incidence of graft failure between the Preprotocol and Protocol groups. We conclude that nurse-initiated and -directed glycemic control protocols can be safely and effectively used in the early period after OLT, though we did not identify a beneficial effect on graft function.

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.