Insulin decreases hepatic acute phase protein levels in severely burned children

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.

Hepatic functional pathophysiology and morphological damage following severe burns: a systematic review and meta-analysis

INTRODUCTION

Severe burns are devastating injuries affecting multiple organ systems. Little is known about the influence on the hepatic system and its physiology. This systematic review aimed to assess the current state of research on morphologic liver damage following severe burns.

METHODS

A search was conducted in Pubmed, Web of Science and Cochrane databases using PRISMA guidelines. Outcomes included serum levels of transaminases, fatty infiltration and necrosis. Weighted individual study estimates were used to calculate pooled transaminase levels and necrosis/fatty infiltration rates using a random-effects approach. Risk ratios (RRs) or Odds ratios (ORs) and 95% confidence intervals (CIs) were used to describe pooled estimates for risk factors.

RESULTS

The literature search retrieved 2548 hits, of which 59 studies were included into qualitative synthesis, and finally ten studies were included into meta-analysis. Studies were divided into those reporting autopsies and those reporting changes of serum transaminase levels. The majority of liver autopsies showed fatty infiltration 82% (95% CI39%-97%) or necrosis of the liver 18% (95% CI13%-24%).

DISCUSSION

Heterogeneity in studies on hepatic functional damage following severe burns was high. Only few were well-designed and published in recent years. Many studies could not be included because of insufficient numerical data. There is a high number of patients deceasing from burns that present with fatty infiltration or necrosis of hepatic tissue. Transaminases were elevated during the first days after burn. Further research on how severe burns affect the hepatic function and outcome, especially long-term, is necessary.

Nutritional management of a kitten with thermal burns and septicaemia

Case summary

A 3-month-old entire female British Shorthair cat presented for further management of thermal burns after falling into a bath of scalding water. On presentation to the primary care clinician the kitten was obtunded, markedly painful and relatively bradycardic, consistent with a state of shock. The haircoat was wet, with erythematous skin and sloughing from the digital pads and anal mucosa. The primary care clinician administered opioid analgesia, sedation, antibiotics and started intravenous (IV) fluid therapy prior to referral. On arrival to the referral hospital the kitten was obtunded with respiratory and cardiovascular stability but was overtly painful and resistant to handling. The kitten required intensive management with IV and regional analgesia, IV broad-spectrum antibiosis, IV fluid therapy, enteral nutrition and wound management, including surgical debridement and topical antibiotic therapy. Septicaemia developed during the hospitalisation. Multidrug-resistant Escherichia coli and Pseudomonas aeruginosa were cultured, and antibiosis was escalated to IV imipenem. Acute respiratory distress syndrome was suspected following the development of dyspnoea. Early enteral nutrition within 24 h of admission was initiated using an oesophageal feeding tube and a veterinary therapeutic liquid diet. Over the ensuing 72 h the kitten started voluntary intake of food alongside oesophageal tube feeds. The kitten experienced continued weight loss despite the provision of nutritional support to meet, and then later exceed, the estimated resting energy requirements. Caloric intake was gradually increased to a total of 438% of the calculated resting energy requirement using the most recent daily body weight, eventually resulting in stabilisation of weight loss and weight gain.

Relevance and novel information

There is limited published information on the nutritional management of veterinary patients with thermal burn injury. Hypermetabolic states related to burn injuries are induced and maintained by complex interactions of catecholamines, stress hormones and inflammatory cytokines on proteolysis, lipolysis and glycogenolysis. Secondary infections are common following burn injury and the subsequent proinflammatory state perpetuates hypermetabolism and catabolism. These states present a challenge in both predicting and providing adequate nutrition, particularly in a paediatric septic patient. This subset of patients should be monitored closely during hospitalisation to ensure body weight and condition are maintained (while taking into consideration hydration status), and caloric intake is adjusted accordingly to meet nutritional support goals. Extensive research exists regarding the nutritional requirements and metabolic derangements of people with thermal burns. However, the importance of maintaining body weight and body condition in veterinary burn patients, and the association between nutritional support and reduced morbidity and mortality, has not been investigated and remains to be elucidated.

Effects of hepato-preferential basal insulin peglispro on nuclear magnetic resonance biomarkers lipoprotein insulin resistance index and GlycA in patients with diabetes

AIM

To characterize the effects of hepato-preferential basal insulin peglispro (BIL) and insulin glargine on insulin resistance (lipoprotein insulin resistance index [LP-IR]) and inflammation (GlycA), and to explore the biological implications.

METHODS

This substudy included 847 patients with Type 1 diabetes (T1D) or Type 2 diabetes (T2D) in four cohorts of the BIL development program. LP-IR and GlycA were measured before and after insulin treatment. Correlations between LP-IR, GlycA, clinical parameters and liver biomarkers were assessed.

RESULTS

LP-IR and GlycA were higher in T2D than T1D. LP-IR increased in patients switched from basal insulins to BIL but not in insulin-naive patients. GlycA decreased in T2D patients treated with BIL and T1D patients treated with glargine.

CONCLUSION

These exploratory analyses help to characterize differences in biological effects between BIL and glargine treatment.

Complement factors C4 and C3 are down regulated in response to short term overfeeding in healthy young men

Insulin resistance is associated with high circulating level of complement factor C3. Animal studies suggest that improper complement activation mediates high-fat-diet-induced insulin resistance. Individuals born with low birth weight (LBW) are at increased risk of developing insulin resistance. We hypothesized that high-fat overfeeding (HFO) increase circulating C3 and induce complement activation in a birth weight differential manner. Twenty LBW and 26 normal birth weight (NBW) young men were studied using a randomised crossover design. Insulin resistance was measured after a control-diet and after 5-days HFO by a hyperinsulinemic-euglycemic-clamp. Circulating C4, C3, ficolins, mannose-binding-lectin, complement activation products C3bc, terminal complement complex (TCC) and complement activation capacity were determined using turbidimetry and ELISA. HFO induced peripheral insulin resistance in LBW individuals only, while both groups had the same degree of hepatic insulin resistance after HFO. Viewing all individuals circulating levels of C4, C3, C3bc, TCC and complement activation capacity decreased paradoxically along the development of insulin resistance after HFO (P = 0.0015, P < 0.0001, P = 0.01, P < 0.0001, P = 0.0002, P < 0.0001, P = 0.0006). Birth weight did not influence these results. This might reflect a hitherto unrecognized down-regulatory mechanism of the complement system. More human studies are needed to understand the underlying physiology and the potential consequences of these findings.

Postburn Hypermetabolism: Past, Present, and Future

Hypermetabolism is the ubiquitous response to a severe burn injury, which was first described in the nineteenth century. Despite identification of important components of this complex response, hypermetabolism is still not well understood in its entirety. This article describes this incredibly fascinating response and the understanding we have gained over the past 100 years. Additionally, this article describes novel insights and delineates treatment options to modulate postburn hypermetabolism with the goal to improve outcomes of burn patients.

Cardiovascular Dysfunction Following Burn Injury: What We Have Learned from Rat and Mouse Models

Severe burn profoundly affects organs both proximal and distal to the actual burn site. Cardiovascular dysfunction is a well-documented phenomenon that increases morbidity and mortality following a massive thermal trauma. Beginning immediately post-burn, during the ebb phase, cardiac function is severely depressed. By 48 h post-injury, cardiac function rebounds and the post-burn myocardium becomes tachycardic and hyperinflammatory. While current clinical trials are investigating a variety of drugs targeted at reducing aspects of the post-burn hypermetabolic response such as heart rate and cardiac work, there is still a paucity of knowledge regarding the underlying mechanisms that induce cardiac dysfunction in the severely burned. There are many animal models of burn injury, from rodents, to sheep or swine, but the majority of burn related cardiovascular investigations have occurred in rat and mouse models. This literature review consolidates the data supporting the prevalent role that β-adrenergic receptors play in mediating post-burn cardiac dysfunction and the idea that pharmacological modulation of this receptor family is a viable therapeutic target for resolving burn-induced cardiac deficits.

Orosomucoid 1 drives opportunistic infections through the polarization of monocytes to the M2b phenotype

Orosomucoid (ORM, composed of two isoforms, ORM1 and ORM2) has been described as an inducer of M2 macrophages, which are cells that decrease host antibacterial innate immunities. However, it is unknown which phenotypes of M2 macrophages are induced by ORM. In this study, healthy donor monocytes stimulated with ORM (ORM-monocytes) were characterized phenotypically and biologically. CCL1 (a biomarker of M2b macrophages) and IL-10 were detected in monocyte cultures supplemented with ORM1; however, CCL17 (a biomarker of M2a macrophages) and CXCL13 (a biomarker of M2c macrophages) were not produced in these cultures. All of these soluble factors were not detected in the culture fluids of monocytes stimulated with ORM2. Monocytes stimulated with ORM1 were characterized as CD64(-)CD209(-)CD163(+)CCL1(+) cells. MRSA and Enterococcus faecalis infections were accelerated in chimeras (NOD/scid IL-2Rγ(null) mice reconstituted with white blood cells) after inoculation with monocytes stimulated with ORM1 or treatment with ORM1; however, the infections were greatly mitigated in both chimeras inoculated with ORM1-stimulated monocytes and treated with ORM1, after an additional treatment with an inhibitor of M2b macrophages (CCL1 antisense ODN). These results indicate that ORM1 stimulates quiescent monocytes to polarize to M2b monocytes. The regulation of M2b macrophages may be beneficial in controlling opportunistic infections in patients with a large amount of plasma ORM1.

Bacterial respiratory tract infections are promoted by systemic hyperglycemia after severe burn injury in pediatric patients

BACKGROUND

Burns are associated with hyperglycemia leading to increased incidence of infections with pneumonia being one of the most prominent and adverse complications. Recently, various studies in critically ill patients indicated that increased pulmonary glucose levels with airway/blood glucose threshold over 150 mg/dl lead to an overwhelming growth of bacteria in the broncho-pulmonary system, subsequently resulting in an increased risk of pulmonary infections. The aim of the present study was to determine whether a similar cutoff value exists for severely burned pediatric patients.

METHODS

One-hundred six severely burned pediatric patients were enrolled in the study. Patients were divided in two groups: high (H) defined as daily average glucose levels >75% of LOS >150 mg/dl), and low (L) with daily average glucose levels >75% of the LOS <150 mg/dl). Incidences of pneumonia, atelectasis, and acute respiratory distress syndrome (ARDS) were assessed. Incidence of infections, sepsis, and respiratory parameters were recorded. Blood was analyzed for glucose and insulin levels. Statistical analysis was performed using Student's t-test and chi-square test. Significance was set at p<0.05.

RESULTS

Patient groups were similar in demographics and injury characteristics. Pneumonia in patients on the mechanical ventilation (L: 21%, H: 32%) and off mechanical ventilation (L: 5%, H: 15%), as well as ARDS were significantly higher in the high group (L: 3%, H: 19%), p<0.05, while atelectasis was not different. Patients in the high group required significantly longer ventilation compared to low patients (p<0.05). Furthermore, incidence of infection and sepsis were significantly higher in the high group, p<0.05.

CONCLUSION

Our results indicate that systemic glucose levels over 150 mg/dl are associated with a higher incidence of pneumonia confirming the previous studies in critically ill patients.

Insulin increases resistance to burn wound infection-associated sepsis

OBJECTIVE

This study was designed to determine the ability of insulin to improve outcome following a Pseudomonas aeruginosa wound infection in a rodent model of severe burn injury.

BACKGROUND

Severe burn injury predisposes patients to burn wound infections that can disseminate, lead to uncontrolled inflammation, and induce septic shock. Whereas insulin administration has been extensively discussed to improve morbidity and mortality in critically ill patients, the ability of insulin to improve outcomes of severely burned patients with infected burn wounds is not known.

DESIGN

Sprague-Dawley rats.

SETTING

University setting.

INTERVENTION

Burn-injured Sprague Dawley rats were randomized into treatment groups that received either saline or insulin. Burn wounds were topically inoculated with a lethal dose of Pseudomonas aeruginosa 6 days after injury.

MEASUREMENTS AND MAIN RESULTS

Survival, systemic dissemination of bacteria, systemic inflammation, and immune activation were examined. Insulin decreased the early inflammatory response to a severe burn injury. Treatment with low doses of insulin following burn injury improved the outcome of rats in response to a lethal burn wound infection. Specifically, survival was improved and systemic dissemination of bacteria from the wound was decreased. Systemic inflammation, indicated by serum interleukin-6 levels, was significantly decreased by insulin treatments after injury. Additionally, insulin treatments were associated with alterations in B and T lymphocyte responses to wound infection.

CONCLUSIONS

Although the mechanisms by which insulin improves outcome following a lethal burn wound infection are not known, the data suggest that immunologic responses to infection may be altered by postburn insulin treatments.

Adiponectin, retinol-binding protein 4, and leptin in protracted critical illness of pulmonary origin

Introduction

Critically ill patients requiring intensive care uniformly develop insulin resistance. This is most pronounced in patients with sepsis. Recently, several hormones secreted by adipose tissue have been identified to be involved in overall insulin sensitivity in metabolic syndrome-related conditions. However, little is known about these adipokines in critical illness.

Methods

We studied circulating levels of the adipokines adiponectin, retinol-binding protein 4 (RBP4), and leptin during critical illness, and the impact of intensive insulin therapy, a therapy shown to affect insulin sensitivity, in serum samples from prolonged critically ill patients with a respiratory critical illness (n = 318). For comparison, we studied healthy subjects (n = 22) and acutely stressed patients (n = 22).

Results

During acute critical illness, circulating levels of adiponectin, RBP4, and leptin were low. Patients with sepsis had lower levels of leptin and RBP4 than did nonseptic patients. When critical illness was sustained, adipokine levels returned to normal reference values. Insulin therapy enhanced adiponectin, blunted the rise of RBP4, and did not alter leptin levels.

Conclusions

Acute critical illness is associated with immediate, but transiently low serum adipokine levels. Adiponectin and RBP4 are associated with altered insulin resistance in critical illness.

Relationship of serum C-reactive protein and blood glucose levels with injury severity and patient morbidity in a pediatric trauma population

PURPOSE

Serum markers of inflammation and of glucose production are known to reflect the immediate metabolic response to injury. We hypothesized that monitoring of the early C-reactive protein (CRP) and blood glucose (BG) concentrations would correlate with clinical morbidity and outcome measures in pediatric trauma patients.

METHODS

A five-year retrospective chart review of pediatric trauma patients admitted to our Level I pediatric trauma center was conducted to establish the relationships between early (first 3 hospital days) serum CRP and BG concentrations, Injury Severity Score (ISS), and hospital length of stay (HLOS). Statistical significance (P < 0.05) was determined using Student's t-test.

RESULTS

Forty-two trauma patients (8.0 +/- 5.2 years) were evaluated. The early inflammatory response (CRP >or= 10 vs <10 mg/dl) was significantly correlated to the glycemic response (BG;121 +/- 24 vs 97.3 +/- 14.2 mg/dl, P < 0.05). Severely injured patients (ISS >or= 25 vs <25) were significantly more hyperglycemic (BG;156 +/- 56.9 vs 125 +/- 31.6 mg/dL, P = 0.003). Both increased inflammatory response (CRP;8.1 +/- 6.4 vs 2.5 +/- 3.5 mg/dL) and increased glycemic response (BG;111 +/- 15.9 vs 97.4 +/- 11.7 mg/dL) were independently and significantly associated with prolonged hospitalization (HLOS > 7 vs <or=7 days, P < 0.05).

CONCLUSION

This study establishes a significant relationship between the early inflammatory and glycemic injury response and the association of that response with pediatric trauma patient morbidity and outcome measures.

Effect of sub-deficient zinc status on insulin sensitivity after burn injury in rats

Although zinc status is an important parameter in insulin sensitivity, data concerning its implication in noxious burn-induced insulin resistance are scarce. The present study was designed to evaluate the impact of zinc status before burn on the recovery of injury with focus on plasma insulin and glucose levels. The experiment was performed in male adult Wistar rats fed from weaning with a zinc normal diet (80 ppm) or a depleted zinc diet (10 ppm) for 8 weeks and burned to third degree on 20% of their total body surface area. Blood and tissue samples were collected 3, 6, and 24 h after injury in order to study biochemical parameters and the glucose/insulin response in relation with the zinc status. After burn, zinc-depleted rats presented an exacerbated decrease in plasma zinc level. In addition, the burn-induced insulin resistance, leading to protein catabolism, was emphasized, with higher plasma insulin, glucose, and leptin levels in zinc-deficient animals versus normal-fed rats. Our experimental results underlined the interest to early control the zinc status in order to limit the deleterious effects of oxidative stress and insulin resistance in burned patients.

Metabolic implications of severe burn injuries and their management: a systematic review of the literature

BACKGROUND

Severe burn patients are some of the most challenging critically ill patients, with an extreme state of physiologic stress and an overwhelming systemic metabolic response. A major component of severe burn injury is a hypermetabolic state associated with protein losses and a significant reduction of lean body mass. The second prominent component is hyperglycemia. Reversal of the hypermetabolic response by manipulating the patient's physiologic and biochemical environment through the administration of specific nutrients, growth factors, or other agents, often in pharmacologic doses, is emerging as an essential component of the state of the art in severe burn management. The present review aims at summarizing the new treatment modalities established to reduce the catabolic burden of severe burn injuries, for which there is some evidence-based support.

METHODS

A systematic review of the literature was conducted. Search tools included Elsevier ScienceDirect, EMBASE.com, Medline (OVID), MedlinePlus, and PubMed. Topics searched were Nutrition and Burns, Metabolic Response and Burns, Hypermetabolism and Burns, Hyperglycemia and Burns, and several more specific topics when indicated. With a focus on the most recently published articles, abstracts were reviewed and, when found relevant, were included as references. Full text articles, whenever available, were retrieved.

RESULTS

Many issues remain unanswered. Unfortunately, the present state of our knowledge does not allow the formulation of clear-cut guidelines. Only general trends can be outlined, and these will certainly have some practical applications but above all will dictate future research in the field.

Nutritional therapy for burns in children and adults

Burns are a serious injury that requires optimal nutritional support. This review discusses the nutritional care for adults and children with major burns. A burned patient's metabolism is greatly accelerated with increased requirements for energy, carbohydrates, proteins, fats, vitamins, minerals, and antioxidants. Early nutrition by parenteral and enteral feedings is vital. Careful assessment of the nutritional state of the burn patient is also important to reduce infection, recovery time, and long-term sequelae.

Intensive insulin therapy is associated with reduced infectious complications in burn patients

BACKGROUND

Intensive insulin therapy to control blood glucose levels has reduced mortality in surgical, but not medical, intensive care unit (ICU) patients. Control of blood glucose levels has also been shown to reduce morbidity in surgical ICU patients. There is very little data for use of intensive insulin therapy in the burn patient population. We sought to evaluate our experience with intensive insulin therapy in burn-injured ICU patients with regard to mortality, morbidity, and use of hospital resources.

STUDY DESIGN

Burn patients admitted to our American College of Surgeons verified burn center ICU from 7/1/2004 to 6/30/2006 were studied. An intensive insulin therapy protocol was initiated for ICU patients admitted starting 7/1/2005 with a blood glucose target of 100-140 mg/dL. The 2 groups of patients studied were control (7/1/2004 to 6/30/2005) and intensive insulin therapy (7/1/2005 to 6/30/2006). All glucose values for the hospitalization were analyzed. Univariate and multivariate analyses were performed.

RESULTS

Overall, 152 ICU patients admitted with burn injury were available for study. No difference in mortality was evident between the control and intensive insulin therapy groups. After adjusting for patient risk, the intensive insulin therapy group was found to have a decreased rate of pneumonia, ventilator-associated pneumonia, and urinary tract infection. In patients with a maximum glucose value of greater than 140 mg/dL, the risk for an infection was significantly increased (OR 11.3, 95% CI 4-32, P-value < .001). The presence of a maximum glucose value greater than 140 mg/dL was associated with a sensitivity of 91% and specificity of 62% for an infectious complication.

CONCLUSION

Intensive insulin therapy for burn-injured patients admitted to the ICU was associated with a reduced incidence of pneumonia, ventilator-associated pneumonia, and urinary tract infection. Intensive insulin therapy did not result in a change in mortality or length of stay when adjusting for confounding variables. Measurement of a blood glucose level greater than 140 mg/dL should heighten the clinical suspicion for the presence of an infection in patients with burn injury.

Postburn trauma insulin resistance and fat metabolism

Hyperglycemia and insulin resistance have long been recognized in severe burn patients. More recently, it has been observed that controlling hyperglycemia, or alleviating insulin resistance, is associated with improved outcomes. This has led to a renewed interest in the etiology of insulin resistance in this population. The postinjury hyperglycemic response appears to be associated with multiple metabolic abnormalities, such as elevated basal energy expenditure, increased protein catabolism, and, notably, significant alterations in fat metabolism. The synergy of all of the responses is not understood, although many studies have been conducted. In this article we will review the present understanding of the relationship between fat metabolism and insulin resistance posttrauma, and discuss some of the recent discoveries and potential therapeutic measures. We propose that the insulin resistance is likely related to the development of "ectopic" fat stores, i.e., triglyceride (TG) storage in sites such as the liver and muscle cells. Deposition of TG in ectopic sites is due to an increase in free fatty acid delivery secondary to catecholamine-induced lipolysis, in conjunction with decreased beta-oxidation within muscle and decreased hepatic secretion of fats. The resultant increases in intracellular TG or related lipid products may in turn contribute to alterations in insulin signaling.

Insulin therapy in the pediatric intensive care unit

BACKGROUND & AIMS

Hyperglycemia is a major risk factor for increased morbidity and mortality in the intensive care unit. Insulin therapy has emerged in adult intensive care units and several pediatric studies are currently being conducted. This review discusses hyperglycemia and the effects of insulin on metabolic and non-metabolic pathways, with a focus on pediatric critical illness.

METHODS

A PubMed search was performed by using the following keywords and limits (("hyperglycemia"[MeSH terms] or ("insulin resistance"[MeSH major topic]) and ("critical care"[MeSH terms] or "critical illness"[MeSH terms])) in different combinations with ("metabolism"[MeSH terms] or "metabolic networks and pathways"[MeSH terms]) and ("outcome"[all fields]) and ("infant"[MeSH terms] or "child"[MeSH terms] or "adolescent"[MeSH terms]). Quality assessment of selected studies included clinical pertinence, publication in peer-reviewed journals, objectivity of measurements and techniques used to minimize bias. Reference lists of such studies were included.

RESULTS

The magnitude and duration of hyperglycemia are associated with increased morbidity and mortality in the pediatric intensive care unit (PICU), but prospective, randomized controlled studies with insulin therapy have not been published yet. Evidence concerning the mechanism and the effect of insulin on glucose and lipid metabolism in pediatric critical illness is scarce. More is known about the positive effect on protein homeostasis, especially in severely burned children. The effect in septic children is less clear and seems age dependent. Some non-metabolic properties of insulin such as the modulation of inflammation, endothelial dysfunction and coagulopathy have not been fully investigated in children.

CONCLUSION

Future studies on the effect of insulin on morbidity and mortality as well as on the mechanisms through which insulin exerts these effects are necessary in critically ill children. We propose these studies to be conducted under standardized conditions including precise definitions of hyperglycemia and rates of glucose intake.

Intensive insulin protocol improves glucose control and is associated with a reduction in intensive care unit mortality

BACKGROUND

Intensive insulin therapy to maintain serum glucose levels between 80 and 110 mg/dL has previously been shown to reduce mortality in the critically ill; recent data, however, have called this benefit into question. In addition, maintaining uniform, tight glucose control is challenging and resource demanding. We hypothesized that, by use of a protocol, tight glucose control could be achieved in the surgical trauma intensive care unit (STICU), and that improved glucose control would be beneficial.

STUDY DESIGN

During the study period, a progressively more rigorous approach to glucose control was used, culminating in an implemented protocol in 2005. We reviewed STICU patients' blood glucose levels, measured by point-of-care testing, from 2003 to 2006. Mortality was tracked over the course of the study, and patient charts were retrospectively reviewed to measure illness and injury severity.

RESULTS

Mean blood glucose levels steadily improved (p < 0.01). In addition to absolute improvements in glucose control, total variability of glucose ranges in the STICU steadily diminished. A reduction in STICU mortality was temporally associated with implementation of the protocol (p < 0.01). There were fewer intraabdominal abscesses and fewer postinjury ventilator days after implementation of the protocol. There was a small increase in the incidence of clinically relevant hypoglycemia.

CONCLUSIONS

Improvements in glucose control in the ICU can be achieved by using a protocol for intensive insulin therapy. In our ICU, this was temporally associated with a significant reduction in mortality.

Insulin attenuates the cytokine response in a burn wound infection model

A massive burn is one of the most serious injuries resulting in major imbalances of the immune system. The aftermath of a burn is frequently complicated by infections and septic events that additionally increase mortality and morbidity. The aim of the present study was to investigate if insulin attenuates the cytokine response of burned mice challenged with Pseudomonas. Male mice (C57/BL/6) received a full thickness burn of 35% of their total body surface area. Mice received 5 IU/kg insulin i.p. or an equal volume of saline for 5 days after burn. Mice were challenged with 5x10 colony forming units Pseudomonas aeruginosa intraperitoneally. Serum was harvested 6 h after the bacterial challenge, and 18 serum cytokines were measured using the Bio-Plex suspension array system (Bio-Rad, Hercules, Calif). All 18 cytokines were elevated after the Pseudomonas challenge. However, mice treated with insulin showed significantly lower proinflammatory cytokine concentrations of interleukin 5, interleukin 6, and keratinocyte-derived chemokine after the Pseudomonas infection when compared with placebo-treated mice (P<0.05). In contrast, serum concentrations of G-CSF were significantly higher in insulin-treated animals when compared with placebo (P<0.05). We conclude, that insulin treatment selectively modulates specific cytokines in a burn wound infection model.

Hyperglycemia Has a Stronger Relation with Outcome in Trauma Patients than in Other Critically Ill Patients

BACKGROUND

Acute hyperglycemia is associated with adverse outcome in critically ill patients. Glucose control with insulin improves outcome in surgical intensive care unit (SICU) patients, but the effect in trauma patients is unknown. We investigated hyperglycemia and outcome in SICU patients with and without trauma.

METHODS

A 12-year retrospective study was performed at a 12-bed SICU. We collected the reason for admission, Injury Severity Scores (ISS), and 30-day mortality rates. Glucose measurements were used to calculate the hyperglycemic index (HGI), a measure indicative of overall hyperglycemia during the entire SICU stay.

RESULTS

In all, 5234 nontrauma and 865 trauma patients were studied. Trauma patients were younger, more frequently male, and had both lower median admission glucose (123 versus 133 mg/dL) and HGI levels (8.9 vs. 18.4 mg/dL) than nontrauma patients (p < 0.001). Mortality was 12% in both groups. Area under the receiver-operator characteristic for HGI and mortality was 0.76 for trauma patients and 0.58 for nontrauma patients (p < 0.001). In multivariate analysis, HGI correlated better with mortality in trauma patients than in nontrauma patients (p < 0.001). Head-injury and nonhead-injury trauma patients showed similar glucose levels and relation between glucose and mortality.

CONCLUSIONS

The relation of hyperglycemia and mortality is more pronounced in trauma patients than in SICU patients admitted for other reasons. The different behavior of hyperglycemia in these patients underscores the need for evaluation of intensive insulin therapy in these patients.

Burn-induced alterations of chromium and the glucose/insulin system in rats

Our objective was to demonstrate a role of chromium (Cr) in response to severe burn. A third-degree burn involving 20% of total body surface was applied under anaesthesia in accord with ethical guidelines. Chromium concentrations in liver decreased progressively and were non-detectable on days 5 and 10 following injury. In quadriceps muscle, Cr concentrations increased 6h after injury and then declined significantly within the first day and remained at these levels the following 9 days. Urinary Cr losses were also increased. Changes in kidney, brain and serum Cr were not significant. Non-fasting glucose rose 6h after injury and then returned to levels measured before the burn. There was a significant rise in corticosterone reaching a maximum the first day after injury that was accompanied by significant increases in circulating insulin and glucagon that were maximal after 2 days. Changes in IGF-1 were not significant. In summary, changes in Cr concentrations were associated with an early hyperglycemia, hyperinsulinemia and increased secretion of stress hormones. These observations strongly suggest a mobilization and utilization of Cr following severe burn. Additional studies are needed to document that improved Cr status might lead to improved recovery following burn.

Efeito do tamoxifeno no perfil das proteínas plasmáticas em condição de diabetes mellitus tipo 1

OBJETIVO: Considerando-se que importantes avanços científicos têm sido obtidos através de estudos com Diabetes mellitus experimental, e que a ação do tamoxifeno em humanos permanece obscura, o presente trabalho objetiva acompanhar as modificações promovidas pelo diabetes e tamoxifeno no perfil eletroforético das proteínas plasmáticas. MÉTODOS: Foram utilizados 27 ratos fêmeas Wistar (180-220g peso corporal), divididos randomicamente em 5 grupos: C1 (n=3, receberam veículo), C2 (n=3, sem tratamento), T (n=5, tratados com tamoxifeno, 0,3mg/kg/dia), D (n=8, diabéticos experimentais por estreptozotocina, 45mg/Kg) e DT (n=8, diabéticos tratados com tamoxifeno). A eletroforese foi realizada em acetato de celulose, pH 8,6-8,8, cuba TECNOW, e as fitas foram coradas em Ponceau S. As proteínas totais foram determinadas pelo método do Biureto (Kit Labtest). Os proteinogramas foram obtidos em densitômetro BioSystems BTS-235. RESULTADOS: Albumina diminuiu progressivamente nos grupos T, D e DT; a fração a1 aumentou nos grupos T e DT; a fração a2 aumentou nos grupos T e D, havendo efeito aditivo no grupo DT; a fração b aumentou nos grupos T e D; a fração g aumentou nos grupos T, D e DT. CONCLUSÃO: Os resultados indicam uma resposta de fase aguda, com efeito aditivo do tamoxifeno e diabetes, sugerindo uma provável lesão hepática.