Therapy insight: the effect of tight glycemic control in acute illness

Peak insulin drip rate associated with decreased infections post-solid organ transplant

Infection and rejection outcomes were retrospectively analyzed in patients following liver transplant and separately following heart transplant with patients being stratified by their severity of immediate postoperative insulin resistance as measured by the peak insulin drip rate that was required to reduce glucose levels. For each group, these peak insulin drip rates were divided into quartiles (Q). In liver transplant patients (n = 207), those in Q4 (highest infusion rate) had significantly fewer infections up to 6 months post-transplant (42.3% vs. 60.0%, p = .036) and borderline fewer rejection episodes (25.0% vs. 40.0%, p = .066) compared to Q1-Q3 patients. To confirm these unexpected results, a subsequent similar analysis in heart transplant (n = 188) patients again showed that Q4 patients had significantly fewer infections up to 6 months (19.1% vs. 53.9%, p < .0001) compared to Q1-Q3 patients. Logistic regression in a subset of 103 cardiac transplant patients showed that the maximum glucose during surgery, prior MI, and hypertension were associated with severe insulin resistance (SIR) status, while the presence of pre-existing diabetes and BMI were not. We hypothesize that patients are who are able to mount a more robust counter-regulatory response that causes the insulin resistance may be healthier and thus able to mount a better response to infections.

Metabolic and Nutritional Support

Hypermetabolism is a hallmark of larger burn injuries. The hypermetabolic response is characterized by marked and sustained increases in catecholamines, glucocorticoids, and glucagon. There is an increasing body of literature for nutrition and metabolic treatment and supplementation to counter the hypermetabolic and catabolic response secondary to burn injury. Early and adequate nutrition is key in addition to adjunctive therapies, such as oxandrolone, insulin, metformin, and propranolol. The duration of administration of anabolic agents should be at minimum for the duration of hospitalization, and possibly up to 2 to 3 years postburn.

The combination of omega-3 fatty acids with high doses of vitamin D3 elevate A1c levels: A randomized Clinical Trial in people with vitamin D deficiency

PURPOSE

This randomised clinical trial (RCT) was created to assess the influence of 1,25-dihydroxyvitamin D (VD₃ ), omega-3 fatty acids (n-3FA) and their combination (D+) on glycated haemoglobin (A1c) levels in Jordanian peoples with vitamin D deficiency (VDD).

PARTICIPANTS AND METHODS

This RCT was designed to examine the follow-up (2 months) effect of either 50 000 IU VD₃ , 300 mg n-3FA, or the combination of the two supplements on glycated Haemoglobin (A1c) levels in 146 Jordanian women and men with VDD, aged from 25 to 55 years. The eligible participants were randomised into four groups: Control (C); VD₃ supplementation (50 000 IU of VD₃ was taken weekly) (D₃ ); n-3FA supplementation (300 mg of omega-3FA was taken daily) (n-3FA); VD₃ and omega-3 supplementation group (D+) with the same protocol as the previous two groups.

RESULTS

The combination therapy (n-3FA plus VD3) for 8 weeks significantly increased A1c levels (5.79 ± 0.34 vs 5.41 ± 0.33, P < .001). Tukey test for post hoc comparisons of A1c at follow-up showed that the A1c mean levels were remarkably higher in the D+ study group comparing to the control group (5.78 vs 5.38).

CONCLUSION

The intervention of n-3FA alone or in combination with high doses of VD₃ may lead to negative effects on glycaemic control or accelerate the insulin resistance's development in susceptible people for diabetes mellitus (type 2).

Guida pratica alla prevenzione e gestione dell’infezione da COVID-19 nelle persone con diabete

La pandemia di COVID-19 rappresenta un’enorme sfida per il sistema sanitario nazionale. Sulla base dei dati ad oggi disponibili è emerso che le persone con diabete mellito presentano un maggior rischio di complicanze e morte per COVID-19. Pertanto, adottare misure preventive di igiene e di distanziamento sociale è cruciale, a maggior ragione in questa categoria di soggetti. A sostegno dei pazienti con diabete sono state intraprese molteplici iniziative al fine di garantire la continuità assistenziale, tra cui la proroga della validità dei piani terapeutici per i farmaci ipoglicemizzanti, le procedure per il rinnovo della patente di guida e l’attivazione di servizi di telemedicina. In caso di infezione da COVID-19 e sintomi lievi è possibile una gestione domiciliare della persona con diabete, raccomandando un attento monitoraggio glicemico. Il paziente diabetico che necessita di ospedalizzazione richiede una gestione multidisciplinare che includa il diabetologo, con l’obiettivo di mantenere un adeguato controllo glicemico in assenza di ipoglicemie. Le persone con diabete rappresentano un gruppo vulnerabile per il quale devono essere poste in atto strategie specifiche sia in termini di prevenzione che di trattamento.

Towards a fasting-mimicking diet for critically ill patients: the pilot randomized crossover ICU-FM-1 study

BACKGROUND

In two recent randomized controlled trials, withholding parenteral nutrition early in critical illness improved outcome as compared to early up-to-calculated-target nutrition, which may be explained by beneficial effects of fasting. Outside critical care, fasting-mimicking diets were found to maintain fasting-induced benefits while avoiding prolonged starvation. It is unclear whether critically ill patients can develop a fasting response after a short-term nutrient interruption. In this randomized crossover pilot study, we investigated whether 12-h nutrient interruption initiates a metabolic fasting response in prolonged critically ill patients. As a secondary objective, we studied the feasibility of monitoring autophagy in blood samples.

METHODS

In a single-center study in 70 prolonged critically ill patients, 12-h up-to-calculated-target feeding was alternated with 12-h fasting on day 8 ± 1 in ICU, in random order. Blood samples were obtained at the start of the study, at the crossover point, and at the end of the 24-h study period. Primary endpoints were a fasting-induced increase in serum bilirubin and decrease in insulin requirements to maintain normoglycemia. Secondary outcomes included serum insulin-like growth factor I (IGF-I), serum urea, plasma beta-hydroxybutyrate (BOH), and mRNA and protein markers of autophagy in whole blood and isolated white blood cells. To obtain a healthy reference, mRNA and protein markers of autophagy were assessed in whole blood and isolated white blood cells of 23 matched healthy subjects in fed and fasted conditions. Data were analyzed using repeated-measures ANOVA, Fisher's exact test, or Mann-Whitney U test, as appropriate.

RESULTS

A 12-h nutrient interruption significantly increased serum bilirubin and BOH and decreased insulin requirements and serum IGF-I (all p ≤ 0.001). Urea was not affected. BOH was already increased from 4 h fasting onwards. Autophagic markers in blood samples were largely unaffected by fasting in patients and healthy subjects.

CONCLUSIONS

A 12-h nutrient interruption initiated a metabolic fasting response in prolonged critically ill patients, which opens perspectives for the development of a fasting-mimicking diet. Blood samples may not be a good readout of autophagy at the tissue level.

TRIAL REGISTRATION

ISRCTN, ISRCTN98404761. Registered 3 May 2017.

Glycemic control with insulin attenuates sepsis-associated encephalopathy by inhibiting glial activation via the suppression of the nuclear factor kappa B and mitogen-activated protein kinase signaling pathways in septic rats

Sepsis-associated encephalopathy (SAE) is frequently encountered in critically ill patients. Hyperglycemia is a common phenomenon among patients with sepsis, and glycemic control improves patient outcomes. Therefore, here, we aimed to explore whether glycemic control using insulin inhibits the pro-inflammatory cytokine response and glial activation in the cerebrum and is concomitantly associated with the relief of SAE. Using cecal ligation and puncture (CLP), sepsis was induced in male Sprague-Dawley rats. The CLP rats were administered intravenous glucose or subjected to subcutaneous insulin implant within the first hour after CLP. The survival rate, blood glucose (BG) values, and behavioral expression were assessed daily for 5 days after CLP. At day 5 after CLP, electroencephalography (EEG) recordings and blood-brain barrier (BBB) permeability testing were performed. Immunohistochemistry, immunoblotting, and enzyme-linked immunosorbent assays were used to evaluate glial activation and the pro-inflammatory cytokine response qualitatively and quantitatively, respectively. The glucose-treated CLP rats (BG > 390 mg/dL) exhibited a decline in survival rate; insensitivity to mechanical and thermal stimuli; slowed EEG activity; and an increase in BBB permeability, pro-inflammatory cytokine (TNF-α, IL-1β, and IL-6) levels, and glial activation (astrocytes and microglia) in the cerebral tissues compared with CLP rats (BG ~ 270 mg/dL). Double-immunofluorescence showed that activated astrocytes and microglia co-expressed phosphorylated nuclear factor kappa B and mitogen-activated protein kinases, respectively. Furthermore, glycemic control using insulin therapy maintained the BG at 120-160 mg/dL and inhibited the production of pro-inflammatory cytokines and glial activation in the cerebrum of septic rats. In addition, the survival rate, sensory threshold, EEG activity, and BBB permeability recovered to near-normal levels in septic rats after insulin therapy. Taken together, the results of this study elucidated the pathophysiological alterations in brains subjected to sepsis, especially regarding glycemic control. These findings improve our understanding of SAE and support the importance of glycemic control in sepsis.

Activation of AMPK alleviates cardiopulmonary bypass-induced cardiac injury via ameliorating acute cardiac glucose metabolic disorder

Recent years, studies have demonstrated that hyperglycemia is one of the main manifestations after cardiac surgeries, which contributes to myocardial injuries and increases the chance of subsequent complications and mortality in such patients. However, strategies targeting at glucose metabolic disorder after cardiac surgeries to attenuate myocardial injuries are inadequately studied. In this study, a rat model of cardiopulmonary bypass (CPB) was applied to investigate the role of Adenosine 5'-monophosphate-activated protein kinase (AMPK) in modulating myocardial glucose metabolic-induced cardiac injuries after cardiac surgery. The results revealed that CPB elicited significant cardiac dysfunction, and pronouncedly elevated the markers of myocardial injuries including serum creatine kinase MB and cardiac troponin I. Additionally, blunted myocardial glucose uptake after CPB was associated with decreased membrane glucose transporter 4 (GLUT4) content. However, pretreatment of AMPK agonist 5-aminoimidazole-4-carboxamide1-β-D-ribofuranoside (AICAR) at the beginning of CPB activated AMPK, enhanced phosphorylation of Akt substrate 160 (AS160), and increased myocardial membrane content of GLUT4. Meanwhile, improved myocardial glucose uptake and more importantly alleviated cardiac injury were also observed after CPB pretreated with AICAR. Moreover, the application of a mutant form of AS160 (AS160-4P) abolished the beneficial effect of AICAR, as evidenced by impaired cardiac glucose uptake, reduced myocardial membrane GLUT-4 translocation, increased cardiac injury markers, and deterioration of cardiac function after CPB. In conclusion, it was suggested in this study that preactivation of AMPK by AICAR improved myocardial glucose uptake by promoting AS160 dependent myocardial membrane GLUT-4 translocation, which ultimately provided a potent cardioprotective effect.

How do I manage hyperglycemia/post-transplant diabetes mellitus after allogeneic HSCT

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients frequently develop glucose intolerance and post-transplant diabetes mellitus (PTDM). The clinical importance of PTDM and its detrimental impact on HSCT outcomes are under-recognized. After allo-HSCT, various mechanisms can contribute to the development of PTDM. Here we review information about hyperglycemia and PTDM after allo-HSCT as well as PTDM after solid organ transplantation and describe ways to manage hyperglycemia/PTDM after allogeneic HSCT. Taking into consideration a lack of well-established evidence in the field of allo-HSCT, more studies should be conducted in the future, which will require closer multidisciplinary collaboration between hematologists, endocrinologists and nutritionists.

Association of the -1031T>C polymorphism and soluble TNF-α levels with Acute Coronary Syndrome

INTRODUCTION

Inflammation has gained a pivotal role in the pathophysiology of Acute Coronary Syndrome (ACS). TNF-α is a pro-inflammatory cytokine that could be a potential biomarker in ACS due to its multiple functions. The rs1799964 TNFA polymorphism (-1031T>C) has been associated with a decrease in gene transcription and cytokine levels.

OBJECTIVE

To determine the association of rs1799964 TNFA polymorphism and TNF-α soluble levels in ACS.

METHODS

A total of 251 patients diagnosed with ACS and 164 individuals without cardiovascular diseases classified as the reference group (RG), were included. The rs1799964 polymorphism was genotyped by PCR-RFLP. Soluble protein levels were determined by ELISA. Statistical analyses were performed using chi square and U-Mann Whitney tests.

RESULTS

The genotype and allele frequencies were different between ACS and RG (OR=0.317, p=0.01; OR=0.688, p=0.03 respectively). ACS patients had higher soluble TNF-α levels compared with the RG (31.08 vs 23.00pg/mL, p<0.001); according genotype significant differences were observed (T/T: 24.06 vs T/C: 34.95pg/mL, p=0.0001) in patients. In the RG, T/T carriers showed discrete lower levels than C/C genotype (22.14 vs 27.83pg/mL, p=0.04).

CONCLUSIONS

The -1031C allele of the TNFA polymorphism confers protection for the development of ACS. The T/C genotype carriers had higher TNF-α serum levels compared to the T/T genotype in ACS. In addition, the -1031T>C TNFA polymorphism was associated with dyslipidemia in ACS in a Western Mexican population.

Glycemic Variability: How Do We Measure It and Why Is It Important?

Chronic hyperglycemia is the primary risk factor for the development of complications in diabetes mellitus (DM); however, it is believed that frequent or large glucose fluctuations may independently contribute to diabetes-related complications. Postprandial spikes in blood glucose, as well as hypoglycemic events, are blamed for increased cardiovascular events in DM. Glycemic variability (GV) includes both of these events; hence, minimizing GV can prevent future cardiovascular events. Correcting GV emerges as a target to be pursued in clinical practice to safely reduce the mean blood glucose and to determine its direct effects on vascular complications in diabetes. Modern diabetes management modalities, including glucagon-related peptide-1-based therapy, newer insulins, modern insulin pumps and bariatric surgery, significantly reduce GV. However, defining GV remains a challenge primarily due to the difficulty of measuring it and the lack of consensus regarding the optimal approach for its management. The purpose of this manuscript was not only to review the most recent evidence on GV but also to help readers better understand the available measurement options and how the various definitions relate differently to the development of diabetic complications.

Relationship between Nadir Hematocrit during Cardiopulmonary Bypass and Postoperative Hyperglycemia in Nondiabetic Patients

<p><b>Background:</b> Hyperglycemia is common after cardiac surgery in both diabetic and nondiabetic patients and is associated with increased morbidity and mortality. Association between nadir hematocrit levels on cardiopulmonary bypass (CPB) and postoperative hyperglycemia is not clear. This study was carried out to determine the relationship between nadir hematocrit during CPB and postoperative hyperglycemia in nondiabetic patients.</p><p><b>Methods:</b> Records of 200 nondiabetic patients undergoing coronary artery bypass grafting operation were retrospectively reviewed. In the first analysis, patients were divided into two subgroups according to the presence or absence of hyperglycemia. Further analysis was made after dividing the patients into 3 subgroups according to nadir hematocrit levels on CPB (less than 20%; 20% to 25%; greater than or equal to 25%).</p><p><b>Results:</b> Compared to patients without hyperglycemia, patients with postoperative hyperglycemia had significantly lower preoperative hematocrit levels (p = 0.004) and were associated with lower nadir hematocrit levels during CPB (p= 0.002). Peak intensive care unit blood glucose levels and number of blood transfusions were significantly higher in patients with nadir hematocrit levels less than 20. (p<0.001 and p<0.001 respectively). Logistic regression analysis demonstrated that nadir hematocrit levels less than 20% (OR 2.9, p=0.009) and allogenic blood transfusion (OR 1.5, p=0.003) were independently associated with postoperative hyperglycemia.</p><p><b>Conclusions:</b> Nadir hematocrit levels on CPB less than 20% and allogenic blood transfusions were independently associated with postoperative hyperglycemia in nondiabetic patients. Patients with a nadir hematocrit levels less than 20 % during CPB should be closely monitored for hyperglycemia in the perioperative period.</p>

Hypoglycemia is associated with increased postburn morbidity and mortality in pediatric patients

OBJECTIVE

The objective of this study was to determine the prevalence of hypoglycemia after burn injury and whether hypoglycemia is associated with increased postburn morbidity and mortality.

DESIGN

Cohort analysis.

SETTING

Academic pediatric burn hospital.

PATIENTS

This analysis included 760 pediatric burn patients, who were stratified according the number of hypoglycemic episodes (< 60 mg/dL glucose) they experienced while in the ICU. Clinical outcomes and metabolic and inflammatory biomarkers were analyzed during the first 60 days post admission. Patients with one or more hypoglycemic events were matched with patients not experiencing any event using propensity score matching, and outcomes and biomarker expression were compared between groups.

MEASUREMENTS AND MAIN RESULTS

Eighty-four patients had one episode of hypoglycemia, 108 patients had two or more episodes of hypoglycemia, and 568 patients never experienced hypoglycemia. Patients with one or more hypoglycemic episodes had longer hospitalization, as well as more frequent infections, sepsis, multiple organ failure, and death (p < 0.05). The 166 propensity score-matched patients with one or more hypoglycemic events had greater inflammatory and metabolic responses, prevalence of sepsis, multiple organ failure, and mortality than burn patients without hypoglycemic (p < 0.05).

CONCLUSIONS

Hypoglycemic episodes correlate with injury severity and inhalation injury. When adjusted for injury severity, hypoglycemia is associated with significantly higher postburn morbidity and mortality.

Glucose variability: An emerging target for the treatment of diabetes mellitus

Alterations in glucose metabolism in individuals with diabetes have been considered for many years, as they appear at first glance, i.e., simply as hyperglycemia, and its surrogate marker, glycated hemoglobin (HbA1c), used both to estimate the risk of developing diabetic complications and to define the targets and measure the efficacy of diabetes treatments. However, over time diabetes-related glycemic alterations have been considered in more complex terms, by attempting to identify the role of fasting glycemia, postprandial glycemia and hypoglycemia in the overall assessment of the disease. This set of evaluations has led to the concept of glucose variability. Although intuitively easy to understand, it cannot be equally simply translated into terms of definition, measuring, prognostic and therapeutic impact. The literature available on glucose variability is extensive yet confused, with the only common element being the need to find out more on the subject. The purpose of this manuscript is not only to review the most recent evidence on glucose variability, but also to help the reader to better understand the available measurement options, and how the various definitions can differently be related with the development of diabetic complications. Finally, we provide how new and old drugs can impact on glucose variability.

Clinical review: Glucose control in severely burned patients - current best practice

Tight glucose control changed the way many burn centers practice burn ICU care. However, after the initial impressive data, various clinical trials followed that showed mixed results. The objective of the present review is to discuss recent studies in the area of burn and critical care, and to identify the current best practice for current burn care providers. We reviewed relevant publications from PubMed and selected high-impact publications on tight glycemic control in various patient populations with a focus on burn patients. We conclude that in burns there seems to be a signal that insulin administration to a target range of 130 to 150 mg/dl is beneficial in terms of morbidity and mortality without the risk of hypoglycemia.

Implementation of cerebral microdialysis at a community-based hospital: A 5-year retrospective analysis

Background:

Cerebral microdialysis (MD) provides valuable information about brain metabolism under normal and pathologic conditions. The CMA 600 microdialysis analyzer received US Food and Drug Administration (FDA) approval for clinical use in the United States in 2005. Since then, cerebral MD has been increasingly utilized nationally in the multimodal monitoring of traumatic brain injury (TBI), stroke, aneurysmal subarachnoid hemorrhage, and brain tumors. We describe a 5-year, single-institutional experience using cerebral MD at a community-based hospital, Legacy Emanuel Medical Center (LEMC). Implications for the adoption and utility of MD in medical centers with limited resources are discussed.

Methods:

This is a retrospective chart review and data analysis of 174 consecutive patients who had cerebral MD as part of multimodal brain monitoring. All cerebral MD catheters were placed by board-certified, attending neurosurgeons at LEMC. Clinical severity in the TBI patients was reported using initial Glasgow Coma Scale (GCS); radiologic severity was graded with the Marshall CT grading scale. Measures of the risks of MD placement included post-placement hemorrhage, cerebral infection, and dislodgement.

Results:

Between July 2005 and July 2010, 248 cerebral MD catheters were placed in 174 patients undergoing multimodal brain monitoring. One hundred and eighty-five catheters were placed at the time of open craniotomy. None were associated with cranial infection. Patients ranged in age from 5 months to 90 years, with a mean of 49 years. The male to female ratio was 1.4:1. The underlying pathologies were: TBI (126), cerebral vascular accident (24), aneurysmal subarachnoid hemorrhage (17), and tumor (7).

Conclusions:

Cerebral MD was readily implemented in a community-based hospital. No cerebral hemorrhages or infections were attributed to cerebral MD. Examples of how MD may be a useful adjunct in the clinical decision making of patients with brain injuries are presented.

What do we need beyond hemoglobin A1c to get the complete picture of glycemia in people with diabetes?

Hemoglobin A1c (HbA1c) is currently the most commonly used marker for the determination of the glycemic status in people with diabetes and it is frequently used to guide therapy and especially medical treatment of people with diabetes. The measurement of HbA1c has reached a high level of analytical quality and, therefore, this biomarker is currently also suggested to be used for the diagnosis of diabetes. Nevertheless, it is crucial for people with diabetes and their treating physicians to be aware of possible interferences during its measurement as well as physiological or pathological factors that contribute to the HbA1c concentration without being related to glycemia, which are discussed in this review. We performed a comprehensive review of the literature based on PubMed searches on HbA1c in the treatment and diagnosis of diabetes including its most relevant limitations, glycemic variability and self-monitoring of blood glucose (SMBG). Although the high analytical quality of the HbA1c test is widely acknowledged, the clinical relevance of this marker regarding risk reduction of cardiovascular morbidity and mortality is still under debate. In this respect, we argue that glycemic variability as a further risk factor should deserve more attention in the treatment of diabetes.

Hyperglycaemia and apoptosis of microglial cells in human septic shock

Introduction

The effect of hyperglycaemia on the brain cells of septic shock patients is unknown. The objective of this study was to evaluate the relationship between hyperglycaemia and apoptosis in the brains of septic shock patients.

Methods

In a prospective study of 17 patients who died from septic shock, hippocampal tissue was assessed for neuronal ischaemia, neuronal and microglial apoptosis, neuronal Glucose Transporter (GLUT) 4, endothelial inducible Nitric Oxide Synthase (iNOS), microglial GLUT5 expression, microglial and astrocyte activation. Blood glucose (BG) was recorded five times a day from ICU admission to death. Hyperglycaemia was defined as a BG 200 mg/dL g/l and the area under the BG curve (AUBGC) > 2 g/l was assessed.

Results

Median BG over ICU stay was 2.2 g/l. Neuronal apoptosis was correlated with endothelial iNOS expression (rho = 0.68, P = 0.04), while microglial apoptosis was associated with AUBGC > 2 g/l (rho = 0.70; P = 0.002). Neuronal and microglial apoptosis correlated with each other (rho = 0.69, P = 0.006), but neither correlated with the duration of septic shock, nor with GLUT4 and 5 expression. Neuronal apoptosis and ischaemia tended to correlate with duration of hypotension.

Conclusions

In patients with septic shock, neuronal apoptosis is rather associated with iNOS expression and microglial apoptosis with hyperglycaemia, possibly because GLUT5 is not downregulated. These data provide a mechanistic basis for understanding the neuroprotective effects of glycemic control.

Burns: where are we standing with propranolol, oxandrolone, recombinant human growth hormone, and the new incretin analogs?

PURPOSE OF REVIEW

The hypermetabolic response in critically ill patients is characterized by hyperdynamic circulatory, physiologic, catabolic and immune system responses. Failure to satisfy overwhelming energy and protein requirements after, and during critical illness, results in multiorgan dysfunction, increased susceptibility to infection, and death. Attenuation of the hypermetabolic response by various pharmacologic modalities is emerging as an essential component of the management of severe burn patients. This review focuses on the more recent advances in therapeutic strategies to attenuate the hypermetabolic response and its associated insulin resistance postburn.

RECENT FINDINGS

At present, beta-adrenergic blockade with propranolol represents probably the most efficacious anticatabolic therapy in the treatment of burns. Other pharmacological strategies include growth hormone, insulin-like growth factor, oxandrolone and intensive insulin therapy.

SUMMARY

Novel approaches to the management of critical illness by judicious glucose control and the use of pharmacologic modulators to the hypercatabolic response to critical illness have emerged. Investigation of alternative strategies, including the use of metformin, glucagon-like-peptide-1 and the PPAR-γ agonists are under current investigation.

Blood glucose control in the intensive care unit: benefits and risks

Abnormal blood glucose levels are common during critical illness and are associated with outcomes that correspond to a J-shaped curve, the lowest risk associated with normoglycemia. Three proof-of-concept randomized-controlled-trials performed in the surgical, medical, and pediatric intensive care units of the Leuven University Hospital in Belgium demonstrated that maintaining strict age-adjusted normal fasting levels of glycemia (80-110 mg/dl in adults, 70-100 mg/dl in children, 50-80 mg/dl in infants) with intensive insulin therapy reduced morbidity and mortality as compared with tolerating stress hyperglycemia as a potentially beneficial response. Recently, concern has risen about the safety of this intervention, as a multicenter adult study reported an, as yet unexplained, increased mortality with targeting normoglycemia as compared with an intermediate blood glucose level of around 140 mg/dl. This apparent contradiction may be explained by several methodological differences among studies, comprising, among others, different glucose target ranges in the control groups, different feeding policies, and variable accuracy of tools used for glucose measurement and insulin infusion. Hence, efficacy and safety of intensive insulin therapy may be affected by patient-related and ICU setting-related variables. Therefore, no single optimal blood glucose target range for ICU patients can be advocated. It appears safe not to embark on targeting "age-normal" levels in intensive care units (ICUs) that are not equipped to accurately and frequently measure blood glucose, and have not acquired extensive experience with intravenous insulin administration using a customized guideline. A simple fallback position could be to control blood glucose levels as close to normal as possible without evoking unacceptable blood glucose fluctuations, hypoglycemia, and hypokalemia.

'Glycaemic variability': a new therapeutic challenge in diabetes and the critical care setting

Much attention has been paid recently to the possibility that oscillating glucose may superimpose on glycated haemoglobin (HbA(1c)) in determining the risk for diabetes complications. Furthermore, recent evidence suggests that glucose variability, particularly if accompanied by frequent hypoglycaemic episodes, may adversely alter the prognosis of acutely ill patients. In vitro and animal studies confirm that oscillating glucose is more dangerous than stable constant high glucose, particularly in activating the pathways involved in the pathogenesis of diabetes complications. The production of free radicals, accompanied by an insufficient increase in intracellular antioxidant defences, seems to account for this phenomenon. In humans, studies also confirm that fluctuating glucose levels produce an increase in free radicals as well as endothelial dysfunction, and that these changes are greater than those produced by stable high glucose. Avoiding glucose fluctuations in diabetic patients and in critically ill patients seems to be an emerging therapeutic challenge.

The role of hyperglycemia in burned patients: evidence-based studies

Severely burned patients typically experience a systemic response expressed as increased metabolism, inflammation, alteration of cardiac and immune function, and associated hyperglycemia. Hyperglycemia has been associated with an increased risk of morbidity and mortality in critically ill patients. Until recently and for many years, hyperglycemia has been expectantly managed and considered a normal and desired response of an organism to stress. However, findings reported from recent studies now suggest beneficial effects of intensive insulin treatment of critically ill patients. The literature on the management of hyperglycemia in severely burned patients is sparse, with most of the available studies involving only small numbers of burned patients. The purpose of this article is to describe the pathophysiology of hyperglycemia after severe burns and to review the available literature on the outcome of intensive insulin treatment and other anti-hyperglycemic modalities in burned patients in an evidence-based medical approach.

Failure to recover somatotropic axis function is associated with mortality from pediatric sepsis-induced multiple organ dysfunction syndrome

OBJECTIVES

To describe the associations between mediators of the somatotropic axis and mortality from sepsis-induced multiple organ dysfunction syndrome in children; and to examine the relationship between immune function and the somatotropic axis in this setting.

DESIGN

Retrospective study using banked plasma.

SETTING

Single mixed surgical/medical intensive care unit at a quaternary level children's hospital.

PATIENTS

A total of 24 children (n = 17 survivors, 7 nonsurvivors) with severe sepsis or septic shock and dysfunction of >or=2 organ systems.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Plasma samples were available from days 3, 7, and 14 of multiple organ dysfunction syndrome. Insulin-like growth factor 1 and insulin-like growth factor binding protein 3 levels were measured by chemiluminescence. Immune function was quantified using previously determined ex vivo lipopolysaccharide-induced tumor necrosis factor-alpha production levels and absolute lymphocyte counts. Insulin-like growth factor 1 levels were lower in nonsurvivors compared with survivors (p = .004) with the greatest difference seen on day 14 (25 [25-69] ng/mL vs. 314 [123-582] ng/mL; p = .038). insulin-like growth factor binding protein 3 levels were reduced similarly over time (p = .019). A drop in plasma insulin-like growth factor binding protein 3 level at any time after day 3 of illness resulted in a 35-fold increased odds of death (odds ratio, 35 [1.6-750]; p = .004). Both ex vivo tumor necrosis factor-alpha and absolute lymphocyte count were reduced in nonsurvivors compared with survivors, but these differences occurred earlier (days 3 and 7).

CONCLUSIONS

These data suggest that prolonged reduction of somatotropic axis function is associated with mortality from pediatric sepsis-induced multiple organ dysfunction syndrome. Reductions in innate and adaptive immune function are common in this population and are associated with failure of recovery of the somatotropic axis, although the nature of these relationships remains incompletely understood.

Critical evaluation of connectivity-based point of care testing systems of glucose in a hospital environment

BACKGROUND

In recent years a number of point of care testing (POCT) glucometers were introduced on the market. We investigated the analytical variability (lot-to-lot variation, calibration error, inter-instrument and inter-operator variability) of glucose POCT systems in a university hospital environment and compared these results with the analytical needs required for tight glucose monitoring.

METHODS

The reference hexokinase method was compared to different POCT systems based on glucose oxidase (blood gas instruments) or glucose dehydrogenase (handheld glucometers). Based upon daily internal quality control data, total errors were calculated for the various glucose methods and the analytical variability of the glucometers was estimated.

RESULTS

The total error of the glucometers exceeded by far the desirable analytical specifications (based on a biological variability model). Lot-to-lot variation, inter-instrument variation and inter-operator variability contributed approximately equally to total variance. As in a hospital environment, distribution of hematocrit values is broad, converting blood glucose into plasma values using a fixed factor further increases variance. The percentage of outliers exceeded the ISO 15197 criteria in a broad glucose concentration range.

CONCLUSIONS

Total analytical variation of handheld glucometers is larger than expected. Clinicians should be aware that the variability of glucose measurements obtained by blood gas instruments is lower than results obtained with handheld glucometers on capillary blood.

Insulin resistance postburn: underlying mechanisms and current therapeutic strategies

The profound hypermetabolic response to burn injury is associated with insulin resistance and hyperglycemia, significantly contributing to the incidence of morbidity and mortality in this patient population. These responses are present in all trauma, surgical, or critically ill patients, but the severity, length, and magnitude is unique for burn patients. Although advances in therapeutic strategies to attenuate the postburn hypermetabolic response have significantly improved the clinical outcome of these patients during the past years, therapeutic approaches to overcome stress-induced hyperglycemia have remained challenging. Intensive insulin therapy has been shown to significantly reduce morbidity and mortality in critically ill patients. High incidence of hypoglycemic events and difficult blood glucose titrations have led to investigation of alternative strategies, including the use of metformin, a biguanide, or fenofibrate, a peroxisome proliferator-activated receptor (PPAR)-gamma agonist. Nevertheless, weaknesses and potential side affects of these drugs reinforces the need for better understanding of the molecular mechanisms underlying insulin resistance postburn that may lead to novel therapeutic strategies further improving the prognosis of these patients. This review aims to discuss the mechanisms underlying insulin resistance induced hyperglycemia postburn and outlines current therapeutic strategies that are being used to modulate hyperglycemia after thermal trauma.

A patient with type B insulin resistance syndrome, responsive to immune therapy

BACKGROUND

A 55-year-old woman with vitiligo, hypothyroidism, interstitial lung disease and diabetes mellitus developed severe insulin resistance during a hospital admission for respiratory failure. Before hospitalization, her HbA(1c) level was 8.1% on approximately 100 U/day of insulin. Her interstitial lung disease had been treated with glucocorticoids, but after their withdrawal her insulin requirements had increased dramatically. She remained hyperglycemic (blood glucose levels 16.7-27.8 mmol/l), despite intravenous insulin at doses as high as 30,000 U/day.

INVESTIGATIONS

The patient's serum creatinine level was 301 micromol/l and her liver function tests were normal. A mildly elevated white cell count was present. The patient was diagnosed with pneumonia due to Pseudomonas aeruginosa. When the patient's plasma glucose level was 22.5 mmol/l, her plasma C-peptide level was 0.9 nmol/l and her serum insulin level was 294 pmol/l. At that time the patient was on 2,600 U/day of intravenous insulin aspart. Anti-insulin and anti-islet-cell antibodies were not detected, but anti-insulin-receptor antibodies were found.

DIAGNOSIS

Type B insulin resistance syndrome.

MANAGEMENT

The patient's insulin resistance responded to glucocorticoids and plasmapheresis. After the patient was treated with prednisone (60 mg/day), her insulin requirements decreased within 1 week to pre-admission doses. When steroids were subsequently discontinued, glycemic control deteriorated once again. Plasmapheresis was initiated, inducing a striking acute decline in insulin needs. On a maintenance dose of 10 mg prednisone/day, glucose control improved (HbA(1c) 5.8%) with an average of 60 U of isophane insulin twice daily.