Metabolic response to injury and role of anabolic hormones

Prognostic Value of Serum Glucose Level in Critically Ill Septic Patients on Admission to Pediatric Intensive Care Unit

Background

Sepsis is one of the major causes of admission to the pediatric intensive care unit (PICU), as well as a primary cause of poor outcomes. Glycemic variation may occur because of sepsis resulting in either hypoglycemia or hyperglycemia. Measuring the random blood glucose (RBG) level of patients presenting with sepsis in PICU is an easy way to assess their prognosis.

Objectives

A prospective study was done from February 2023 to June 2023 to evaluate the relation between the outcome of pediatric septic patients and blood glucose level upon PICU admission.

Patients and methods

One hundred three children diagnosed with sepsis underwent clinical assessment upon admission to the PICU and initial labs including blood glucose levels were done. Pediatric Sequential Organ Failure Assessment (pSOFA) was calculated for every patient. The outcome of sepsis including length of stay, review of body systems, and mortality was documented.

Results

Hypoglycemic patients had the highest percentage of non-survivors (20.4%). They had a higher pSOFA score with a median of 11 (interquartile range-IQR 7-15), shorter PICU stay with a median of 2 (IQR 1-6) days, lower RBG with a median of 95 (45-120), a higher percentage of ventilation (55.1%), and a higher percentage of inotropic support (87.8%) with statistical significance with p-value (< 0.001, < 0.001, 0.001, < 0.001, 0.002), respectively.

Conclusion

Critically ill patients with abnormal random blood sugar (RBS) had a higher possibility of non-survival particularly those with hypoglycemia. Accordingly, RBS measurement is a rapid and cheap method that could be used in any emergency and as an early indicator to detect outcome.

How to cite this article

Mohamed AO, Abd El-Megied MA, Hosni YA. Prognostic Value of Serum Glucose Level in Critically Ill Septic Patients on Admission to Pediatric Intensive Care Unit. Indian J Crit Care Med 2023;27(10):754-758.

Weight changes and patterns of weight measurements in hospitalized burn patients: a contemporary analysis

Background

Severe burn is associated with significant changes in body weight due to resuscitation volumes, fluid shifts, a hypermetabolic state, prolonged bed rest, and caloric intake. Our goal was to quantify and describe trends in weight change in patients with burns of all severities under modern treatment conditions and to identify the time points at which these changes occur.

Methods

An institutional review board-approved chart review was conducted of acute burn patients treated at an American Burn Association-verified regional burn center from February 2016 to November 2016. Patients were then divided into three groups based on percent of total burn surface area (%TBSA) burn: 1–19%, 20–39%, and ≥ 40%. Weight was expressed as percent change of weight from baseline. Regression analysis was conducted on percent weight changes for each TBSA group.

Results

We identified 197 burn patients with a length of stay (LOS) of ≥ 7 days. Of the study cohort, 149 had TBSA burn of 1–19%, 27 had TBSA burn of 20–39%, and 21 had TBSA burn of ≥ 40%. All groups had a majority of White male, non-Hispanic patients with mean ages between 40 and 42 years. Burn patients with > 20% TBSA burn had a median increase in weight above baseline of approximately 5 to 8% likely due to resuscitation fluids within the first week of hospitalization. Weight loss below baseline often did not exceed 10% and was more pronounced as LOS increased, mostly in patients with > 20% TBSA burn. Whereas patients with 1–19% TBSA burn on average returned to baseline weight at last measurement, patients with 20–39% TBSA and ≥ 40% TBSA burn continued a decline in weight at 4 weeks (r² = 0.57 and 0.55, respectively) on the same trajectory.

Conclusions

Burn patients with > 20% TBSA burn had an increase in weight above baseline of up to 8%, likely due to resuscitation fluids within the first week of hospitalization. Weight loss below baseline often did not exceed 10% and was more pronounced as LOS increased, mostly in patients with > 20% TBSA burn. Therefore, our patients on average, lost body weight to a lesser extent than the maximum mean loss of 22% of pre-burn weight reported prior to modern treatment conditions.

Rising mortality in patients with combined burn and trauma

Combined trauma in the burn patient has been previously shown to have higher mortality. With improved critical care and multidisciplinary approach, we hypothesized the risk of mortality in combined burn and trauma has decreased. A retrospective analysis of trauma, burn and combined burn-trauma patients in the National Trauma Data Bank was performed comparing years 2007-2015 to years 1994-2002. The impact of burn injuries on mortality in patients with minor trauma has decreased (OR 2.45, CI 2.26-2.66, p<0.001 compared to OR 4.04, CI 4.51-4.66, p<0.001) in years 2007-2015 while the impact of burn injuries on mortality in patients with severe trauma has increased (OR 1.37, CI 1.29-1.47, p<0.001 compared to OR 1.26, CI 1.05-1.51, p<0.001). When controlling for known risk factors of mortality in burn and trauma, the contribution of the severity of trauma on mortality in combined burn-trauma patients with total body surface area ≥20% is negligible. In contrast, an increase in percentage of total body surface area burned is associated with a step-wise increase in mortality for all combined burn-trauma patients. However, the largest impact is seen in patients with minor trauma. This population represents a unique overlap of patients where future collaborative research can help identify best practices and improve outcomes.

Moderate glucose supply reduces hemolysis during systemic inflammation

Background

Systemic inflammation alters energy metabolism. A sufficient glucose level, however, is most important for erythrocytes, since erythrocytes rely on glucose as sole source of energy. Damage to erythrocytes leads to hemolysis. Both disorders of glucose metabolism and hemolysis are associated with an increased risk of death. The objective of the study was to investigate the impact of intravenous glucose on hemolysis during systemic inflammation.

Materials and methods

Systemic inflammation was accomplished in male Wistar rats by continuous lipopolysaccharide (LPS) infusion (1 mg LPS/kg and h, 300 min). Sham control group rats received Ringer’s solution. Glucose was supplied moderately (70 mg glucose/kg and h) or excessively (210 mg glucose/kg and h) during systemic inflammation. Vital parameters (eg, systemic blood pressure) as well as blood and plasma parameters (eg, concentrations of glucose, lactate and cell-free hemoglobin, and activity of lactate dehydrogenase) were measured hourly. Clot formation was analyzed by thromboelastometry.

Results

Continuous infusion of LPS led to a so-called post-aggression syndrome with disturbed electrolyte homeostasis (hypocalcemia, hyperkalemia, and hypernatremia), changes in hemodynamics (tachycardia and hypertension), and a catabolic metabolism (early hyperglycemia, late hypoglycemia, and lactate formation). It induced severe tissue injury (significant increases in plasma concentrations of transaminases and lactate dehydrogenase), alterations in blood coagulation (disturbed clot formation), and massive hemolysis. Both moderate and excessive glucose supply reduced LPS-induced increase in systemic blood pressure. Excessive but not moderate glucose supply increased blood glucose level and enhanced tissue injury. Glucose supply did not reduce LPS-induced alterations in coagulation, but significantly reduced hemolysis induced by LPS.

Conclusion

Intravenous glucose infusion can diminish LPS-related changes in hemodynamics, glucose metabolism, and, more interestingly, LPS-induced hemolysis. Since cell-free hemoglobin is known to be a predictor for patient’s survival, a reduction of hemolysis by 35% only by the addition of a small amount of glucose is another step to minimize mortality during systemic inflammation.

Regulatory effect and mechanisms of carbon monoxide-releasing molecule II on hepatic energy metabolism in septic mice

AIM: To investigate the possible mechanisms of exogenous carbon monoxide-releasing molecule II (CORM-2) intervention on hepatic energy metabolism in experimental sepsis.

METHODS: Forty-eight C57BL/6 mice were randomly divided into four groups (n = 12): sham group; cecal ligation and puncture (CLP) group; CLP + CORM-2 group and CLP + iCORM-2 (inactive CORM-2) group. Survival rates were determined after 72 h. Twenty-four similarly treated mice (n = 6 in each group) were assayed for post-operative continuous blood glucose in the first 36 h. Thirty-six similarly treated mice (n = 9 in each group) underwent micro-positron emission tomography (PET) scanning after tail vein injection of ¹⁸F-fluorodeoxyglucose (FDG) 24 h after operation. Plasma and liver specimens were collected for assay of liver pathology, alanine transaminase (ALT) and aspartate transaminase (AST) activities. Hepatic glucokinase activity, lactic acid levels and mitochondrial swelling were also determined.

RESULTS: Improved survival was observed in CORM-2 treated mice. Both the CLP and CLP + CORM-2 groups had sustained low blood glucose levels within the first post-operative 36 h. ¹⁸F-FDG micro-PET images showed abnormally high levels of hepatic glucose metabolism (standardized uptake value) in the CLP group (2.76 ± 0.39 vs 0.84 ± 0.14, P < 0.01), which declined to normal levels after CORM-2 intervention (1.29 ± 0.32 vs 2.76 ± 0.39, P < 0.05). glucokinase activity was markedly increased in the CLP group (6.38 ± 0.56 U/g vs 4.60 ± 0.21 U/g, P < 0.01), but was normal after CORM-2 intervention (4.74 ± 0.14 U/g vs 6.38 ± 0.56 U/g, P < 0.05). CORM-2 suppressed plasma lactic acid levels (4.02 ± 0.02 mmol/L vs 7.72 ± 2.37 mmol/L, P < 0.05) and protected hepatic mitochondria in CLP mice. CORM-2 intervention also reduced elevated plasma AST (199.67 ± 11.08 U/L vs 379.67 ± 16.34 U/L, P < 0.05) and ALT (63.67 ± 12.23 U/L vs 112.67 ± 9.74 U/L, P < 0.05) activities in CLP mice.

CONCLUSION: The release of CO molecules by CORM-2 protects mitochondria and maintains a stable level of hepatic glucose metabolism. Thus, CORM-2 improves liver function and survival in septic mice.

Development of Metabolic Indicators of Burn Injury: Very Low Density Lipoprotein (VLDL) and Acetoacetate Are Highly Correlated to Severity of Burn Injury in Rats

Hypermetabolism is a significant sequela to severe trauma such as burns, as well as critical illnesses such as cancer. It persists in parallel to, or beyond, the original pathology for many months as an often-fatal comorbidity. Currently, diagnosis is based solely on clinical observations of increased energy expenditure, severe muscle wasting and progressive organ dysfunction. In order to identify the minimum number of necessary variables, and to develop a rat model of burn injury-induced hypermetabolism, we utilized data mining approaches to identify the metabolic variables that strongly correlate to the severity of injury. A clustering-based algorithm was introduced into a regression model of the extent of burn injury. As a result, a neural network model which employs VLDL and acetoacetate levels was demonstrated to predict the extent of burn injury with 88% accuracy in the rat model. The physiological importance of the identified variables in the context of hypermetabolism, and necessary steps in extension of this preliminary model to a clinically utilizable index of severity of burn injury are outlined.

[Burn: An inflammatory process]

Thermal injury induce a two-phase inflammatory response: first, a pro-inflammatory status, resulting in a systemic inflammatory response syndrome, then an anti-inflammatory phase characterized by a profound defect in cellular-mediated immunity. This inflammatory reaction proceeds from complex phenomenons in whom many cellular elements are involved (macrophage is the central one) and very complex molecular products interact (especially cytokines). These phenomenons promote significant physiopathologic consequences, especially on cardiovascular homeostasis and endothelial permeability, that lower the prognosis. The inflammatory reaction can be modified, enhanced or maintained by adverse events (i.e. infection) resulting in degradation of clinical situation. Despite a better comprehension of the phenomenons underlying this inflammatory process, diagnosis or therapeutic applications are at that time disappointing.

Glycemic control in the burn intensive care unit: focus on the role of anemia in glucose measurement

Glycemic control with intensive insulin therapy (IIT) has received widespread adoption secondary to findings of improved clinical outcomes and survival in the burn population. Severe burn as a model for trauma is characterized by a hypermetabolic state, hyperglycemia, and insulin resistance. In this article, we review the findings of a burn center research facility in terms of understanding glucose management. The conferred benefits from IIT, our findings of poor outcomes associated with glycemic variability, advantages from preserved diurnal variation of glucose and insulin, and impacts of glucometer error and hematocrit correction factor are discussed. We conclude with direction for further study and the need for a reliable continuous glucose monitoring system. Such efforts will further the endeavor for achieving adequate glycemic control in order to assess the efficacy of target ranges and use of IIT.

Whole-body CO2 production as an index of the metabolic response to sepsis

Whole-body carbon dioxide (CO2) production (RaCO2) is an index of substrate oxidation and energy expenditure; therefore, it may provide information about the metabolic response to sepsis. Using stable isotope techniques, we determined RaCO2 and its relationship to protein and glucose metabolism in medical patients with sepsis and septic shock. Whole-body CO2 production, an index of basal metabolic rate, was measured in 13 patients with sepsis or septic shock and 7 healthy controls using an i.v. infusion of 13C-sodium bicarbonate. Endogenous leucine flux, leucine oxidation, and nonoxidative disposal, indices of whole-body protein breakdown, catabolism, and synthesis, were measured with an infusion of 1-13C-leucine, and glucose production and clearance were measured with an infusion of 2H2-glucose. There was no difference in mean RaCO2 between the patients and controls, but the patients had a wider range of values. The four patients with the lowest RaCO2 died. Protein breakdown and synthesis and glucose production were significantly faster in patients than in controls (P < 0.05). Whole-body CO2 production was positively correlated with protein breakdown (P = 0.001), protein synthesis (P < 0.01), and glucose clearance (P = 0.01). Patients with low metabolic rates (mean-2 SDs of controls) had slower protein breakdown and decreased glucose clearance compared with patients with high metabolic rates (mean + 2 SDs of controls). Septic patients were both hypometabolic and hypermetabolic. The correlation between RaCO2 and protein breakdown and synthesis as well as glucose clearance suggests that RaCO2 can provide information about substrate metabolism in septic patients. Because hypometabolism was associated with mortality and changes in protein and glucose metabolism in septic patients, it may be a useful clinical indicator of an inadequate metabolic response.

Continuous venovenous hemofiltration in severely burned patients with acute kidney injury: a cohort study

Introduction

Acute kidney injury (AKI) is a common and devastating complication in critically ill burn patients with mortality reported to be between 80 and 100%. We aimed to determine the effect on mortality of early application of continuous venovenous hemofiltration (CVVH) in severely burned patients with AKI admitted to our burn intensive care unit (BICU).

Methods

We performed a retrospective cohort study comparing a population of patients managed with early and aggressive CVVH compared with historical controls managed conservatively before the availability of CVVH. Patients with total body surface area (TBSA) burns of more than 40% and AKI were treated with early CVVH and their outcomes compared with a group of historical controls.

Results

Overall, the 28-day mortality was significantly lower in the CVVH arm (n = 29) compared with controls (n = 28) (38% vs. 71%, P = 0.011) as was the in-hospital mortality (62% vs. 86%, P = 0.04). In a subgroup of patients in shock, a dramatic reduction in the pressor requirement was seen after 24 and 48 hours of treatment. Compared with controls (n = 19), significantly fewer patients in the CVVH group (n = 21) required vasopressors at 24 hours (100% vs 43%, P < 0.0001) and at 48 hours (94% vs 24%, P < 0.0001). In those with acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), there was a significant increase from baseline in the partial pressure of arterial oxygen (PaO₂) to fraction of inspired oxygen (FiO₂) ratio at 24 hours in the CVVH group (n = 16, 174 ± 78 to 327 ± 122, P = 0.003) but not the control group (n = 20, 186 ± 64 to 207 ± 131, P = 0.98).

Conclusions

The application of CVVH in adult patients with severe burns and AKI was associated with a decrease in 28-day and hospital mortality when compared with a historical control group, which largely did not receive any form of renal replacement. Clinical improvements were realized in the subgroups of patients with shock and ALI/ARDS. A randomized controlled trial comparing early CVVH to standard care in this high-risk population is planned.

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.

[Hyperglycemia in the critically ill: meaning and treatment]

Hyperglycemia is commun in critically ill patients without previously known diabetes. Hyperglycemia occurring in these patients is mainly a consequence of stress associated to complex glucose metabolism abnormalities which have deleterious effects on tissues and vascular function. Several epidemiologic and intervention studies had established that hyperglycemia is related to morbidity and mortality. Maintenance of normoglycemia with intensive insulin therapy seems to decrease morbidity and mortalities in severe acute illnesses. However the benefit of most of these intervention trials remain controversial mainly in stroke, myocardial infarction and severe sepsis. Moreover strict normoglycemia required to obtain an optimal benefit increases the risk of hypoglycaemia which may be particularly harmful in patients in critical state.