Hyperglycemia is associated with increased morbidity and mortality rates in neonates with necrotizing enterocolitis

The Vagus Nerve Regulates Immunometabolic Homeostasis in the Ovine Fetus near Term: The Impact on Terminal Ileum

BACKGROUND

Glucosensing elements are widely distributed throughout the body and relay information about circulating glucose levels to the brain via the vagus nerve. However, while anatomical wiring has been established, little is known about the physiological role of the vagus nerve in glucosensing. The contribution of the vagus nerve to inflammation in the fetus is poorly understood. Increased glucose levels and inflammation act synergistically when causing organ injury, but their interplay remains incompletely understood. We hypothesized that vagotomy (Vx) will trigger a rise in systemic glucose levels and this will be enhanced during systemic and organ-specific inflammation. Efferent vagus nerve stimulation (VNS) should reverse this phenotype.

METHODS

Near-term fetal sheep (n = 57) were surgically prepared using vascular catheters and ECG electrodes as the control and treatment groups (lipopolysaccharide (LPS), Vx + LPS, Vx + LPS + selective efferent VNS). The experiment was started 72 h postoperatively to allow for post-surgical recovery. Inflammation was induced with LPS bolus intravenously (LPS group, 400 ng/fetus/day for 2 days; n = 23). For the Vx + LPS group (n = 11), a bilateral cervical vagotomy was performed during surgery; of these n = 5 received double the LPS dose, LPS800. The Vx + LPS + efferent VNS group (n = 8) received cervical VNS probes bilaterally distal from Vx in eight animals. Efferent VNS was administered for 20 min on days 1 and 2 +/10 min around the LPS bolus. Fetal arterial blood samples were drawn on each postoperative day of recovery (-72 h, -48 h, and -24 h) as well as at the baseline and seven selected time points (3-54 h) to profile inflammation (ELISA IL-6, pg/mL), insulin (ELISA), blood gas, and metabolism (glucose). At 54 h post-LPS, a necropsy was performed, and the terminal ileum macrophages' CD11c (M1 phenotype) immunofluorescence was quantified to detect inflammation. The results are reported for p < 0.05 and for Spearman R2 > 0.1. The results are presented as the median (IQR).

RESULTS

Across the treatment groups, blood gas and cardiovascular changes indicated mild septicemia. At 3 h in the LPS group, IL-6 peaked. That peak was decreased in the Vx + LPS400 group and doubled in the Vx + LPS800 group. The efferent VNS sped up the reduction in the inflammatory response profile over 54 h. The M1 macrophage activity was increased in the LPS and Vx + LPS800 groups only. The glucose and insulin concentrations in the Vx + LPS group were, respectively, 1.3-fold (throughout the experiment) and 2.3-fold higher vs. control (at 3 h). The efferent VNS normalized the glucose concentrations.

CONCLUSIONS

The complete withdrawal of vagal innervation resulted in a 72-h delayed onset of a sustained increase in glucose for at least 54 h and intermittent hyperinsulinemia. Under the conditions of moderate fetal inflammation, this was related to higher levels of gut inflammation. The efferent VNS reduced the systemic inflammatory response as well as restored both the concentrations of glucose and the degree of terminal ileum inflammation, but not the insulin concentrations. Supporting our hypothesis, these findings revealed a novel regulatory, hormetic, role of the vagus nerve in the immunometabolic response to endotoxin in near-term fetuses.

Hyperglycemia and prematurity: a narrative review

Hyperglycemia is commonly encountered in extremely preterm newborns and physiologically can be attributed to immaturity in several biochemical pathways related to glucose metabolism. Although hyperglycemia is associated with a variety of adverse outcomes frequently described in this population, evidence for causality is lacking. Variations in definitions and treatment approaches have further complicated the understanding and implications of hyperglycemia on the immediate and long-term effects in preterm newborns. In this review, we describe the relationship between hyperglycemia and organ development, outcomes, treatment options, and potential gaps in knowledge that need further research. IMPACT: Hyperglycemia is common and less well described than hypoglycemia in extremely preterm newborns. Hyperglycemia can be attributed to immaturity in several cellular pathways involved in glucose metabolism in this age group. Hyperglycemia has been shown to be associated with a variety of adverse outcomes frequently described in this population; however, evidence for causality is lacking. Variations in definitions and treatment approaches have complicated the understanding and the implications of hyperglycemia on the immediate and long-term effects outcomes. This review describes the relationship between hyperglycemia and organ development, outcomes, treatment options, and potential gaps in knowledge that need further research.

Lack of Association of A1C With Postoperative Complications in Children With Type 1 or Type 2 Diabetes

Not meeting recommended A1C targets may be associated with postoperative complications in adults, but there are no studies reporting on the relationship between preoperative A1C and postoperative complications in children with type 1 or type 2 diabetes. The objective of this study was to determine whether elevated A1C levels were associated with an increased incidence of postoperative complications in children with diabetes presenting for elective noncardiac surgery or diagnostic procedures. It found no such association, suggesting no need to delay elective surgery in children with diabetes until A1C is optimized.

Model-based subcutaneous insulin for glycemic control of pre-term infants in the neonatal intensive care unit

Hyperglycaemia is a common problem in neonatal intensive care units (NICUs). Achieving good control can result in better outcomes for patients. However, good control is difficult, where poor control and resulting hypoglycaemia reduces outcomes and confounds results. Clinically validated models can provide good control, and subcutaneous insulin delivery can provide more options for insulin therapy for clinicians. However, this combination has only been significantly utilised in adult outpatient diabetes, but could hold benefit for treating NICU infants. This research combines a well-validated NICU metabolic model with subcutaneous insulin kinetics models to assess the feasibility of a model-based approach. Clinical data from 12 very/extremely pre-mature infants was collected for an average study duration of 10.1 days. Blood glucose, interstitial and plasma insulin, as well as subcutaneous and local insulin were modelled, and patient-specific insulin sensitivity profiles were identified for each patient. Modelling error was low, where the cohort median [IQR] mean percentage error was 0.8 [0.3 3.4] %. For external validation, insulin sensitivity was compared to previous NICU cohorts using the same metabolic model, where overall levels of insulin sensitivity were similar. Overall, the combined system model accurately captured observed glucose and insulin dynamics, showing the potential for a model-based approach to glycaemic control using subcutaneous insulin in this cohort. The results justify further model validation and clinical trial research to explore a model-based protocol.

Providing the Best Parenteral Nutrition before and after Surgery for NEC: Macro and Micronutrients Intakes

Necrotizing enterocolitis (NEC) is the main gastrointestinal emergency of preterm infants for whom bowel rest and parenteral nutrition (PN) is essential. Despite the improvements in neonatal care, the incidence of NEC remains high (11% in preterm newborns with a birth weight <1500 g) and up to 20−50% of cases still require surgery. In this narrative review, we report how to optimize PN in severe NEC requiring surgery. PN should begin as soon as possible in the acute phase: close fluid monitoring is advocated to maintain volemia, however fluid overload and electrolytes abnormalities should be prevented. Macronutrients intake (protein, glucose, and lipids) should be adequately guaranteed and is essential in each phase of the disease. Composite lipid emulsion should be the first choice to reduce the risk of parenteral nutrition associated liver disease (PNALD). Vitamin and trace elements deficiency or overload are frequent in long-term PN, therefore careful monitoring should be planned starting from the recovery phase to adjust their parenteral intake. Neonatologists must be aware of the role of nutrition especially in patients requiring long-term PN to sustain growth, limiting possible adverse effects and long-term deficiencies.

Endoplasmic reticulum stress in the acute intestinal epithelial injury of necrotizing enterocolitis

Endoplasmic reticulum (ER) is a dynamic organelle that has many functions including protein synthesis, lipid synthesis, and calcium metabolism. Any perturbation in the ER such as accumulation of unfolded or misfolded proteins in the ER lumen causes ER stress. ER stress has been implicated in many intestinal inflammatory diseases. However, the role of ER stress in acute intestinal epithelial injuries such as necrotizing enterocolitis in preterm neonates, remains incompletely understood. In this review, we introduce ER structure, functions and summarize the intracellular signaling pathways involved in unfolded protein response (UPR), a survival mechanism in which cells exert an adaptive function to restore homeostasis in the ER. However, intense and prolonged ER stress induces apoptotic response which results in apoptotic cell death. We also discuss and highlight recent advances that have improved our understanding of the molecular mechanisms that regulate the ER stress in acute intestinal epithelial injuries such as necrotizing enterocolitis (NEC). We focus on the role of ER stress in influencing gut homeostasis in the neonatal period and on the potential therapeutic interventions to alleviate ER stress-induced cell death in NEC.

Plasma Metabolomics to Evaluate Progression of Necrotising Enterocolitis in Preterm Pigs

Necrotising enterocolitis (NEC) is a microbiome-dependent gut disease in preterm infants in early life. Antibiotic treatment is a common intervention for NEC. How NEC lesions, with or without antibiotics, affect plasma metabolome was explored in this study. Formula-fed preterm pigs were used as a model for human NEC and treated with saline, parenteral or oral antibiotics (n = 15-17) for four days after delivery. Gut tissues were collected for evaluation of NEC-like lesions and plasma for metabolomic analysis by proton nuclear magnetic resonance spectroscopy (¹H-NMR). Metabolites were annotated, quantified and subjected to statistical modelling to delineate the effects of NEC and antibiotic treatment. Presence of severe NEC lesions, not antibiotic treatment, was the main drive for plasma metabolite changes. Relative to other pigs, pigs with severe NEC lesions had higher levels of alanine, histidine and myo-inositol, and lower levels of 3-hydroxybutyric acid and isobutyric acid. Across NEC lesion states (healthy, mild, severe), antibiotics directly affected only a few metabolites (tryptophan, 3-phenyllactic acid). Together and independently, NEC and antibiotic treatment affected circulating metabolites in preterm pigs. Amino acids and plasma metabolites, partly related to the gut microbiome, may be helpful to monitor progression of NEC lesions after proper validation.

Intraoperative dextrose rate during exploratory laparotomies in neonates and the incidence of postoperative hyperglycemia: A retrospective observational study

INTRODUCTION

Compared with the older pediatric population, neonates have greater perioperative morbidity and mortality. Difficulty with glucose regulation may be a contributing modifiable risk factor during perioperative anesthetic management. To mitigate the risk of hyperglycemia in neonates, some providers empirically halve the preoperative rate of dextrose-containing infusions during surgery.

AIM

To assess the association between halving the preoperative maintenance dextrose rate and postoperative euglycemia in neonatal intensive care unit patients undergoing exploratory laparotomies.

METHODS

Neonatal intensive care unit patients who underwent exploratory laparotomy under general anesthesia from 1/1/2014 to 11/21/2019 were included in this analysis. Hyperglycemia and hypoglycemia were defined as >150 mg/dL and <46 mg/dL. A calculated dextrose ratio was utilized to categorize patients into full and half intraoperative dextrose rate cohorts. Univariate analyses were performed with Fisher's exact test, the Wilcoxon rank sum test, or Spearman's correlation. Multivariable analyses with regression models were conducted after graphical evaluation of a predetermined set of independent variables.

RESULTS

107 patients were included in the full dextrose rate cohort and 96 patients in the half dextrose rate cohort with postoperative hyperglycemia occurring in 47 and 28 patients, respectively. On univariate analysis, halving the preoperative dextrose rate was associated with decreased postoperative hyperglycemia (odds ratio: 0.53; 95% CI: 0.28-0.98, P = 0.041). This association continued in the regression model (adjusted odds ratio: 0.49; 95% CI: 0.25-0.80, P = 0.008) after controlling for preoperative dextrose rate, preoperative serum glucose, preoperative pH, surgical duration, postmenstrual age at surgery, and the presence of necrotizing enterocolitis. Only one patient was hypoglycemic postoperatively, and they were in the full dextrose cohort.

CONCLUSION

Halving of preoperative dextrose rates intraoperatively during exploratory laparotomy in neonatal intensive care unit patients was associated with a decreased risk of postoperative hyperglycemia without substantially increasing the occurrence of postoperative hypoglycemia. The practice of halving preoperative dextrose rates may be an effective empirical approach for intraoperative glucose management in the high-risk neonatal population when blood glucose monitoring is challenging.

Correlation between Stable Hyperglycemia and Mortality in Children Admitted to the Pediatric Intensive Care Unit of Imam Hossein Hospital

Background:

Stress-induced hyperglycemia is an important issue among pediatrics admitted in the pediatric intensive care unit (PICU). Former studies have declared that hyperglycemia has a high prevalence rate and could increase the risks of mortality among pediatrics. Here, we aimed to investigate the prevalence rate of hyperglycemia and its effects on mortality among pediatrics in the PICU of the hospital.

Materials and Methods:

This cross-sectional study was performed in 2018–2019 on 88 patients admitted in PICU. Data regarding blood sugar (BS) and other clinical and laboratory parameters were collected. Hyperglycemia was accounted for as BS of >126 mg/dl. Hyperglycemia was divided into: mild (126 <BS <150), moderate (150 <BS <200) and severe (BS >200). The pediatric risk of mortality (PRISM) score was also calculated for each patient during the first 24 h.

Results:

Thirty patients (34.1%) had persistent hyperglycemia and 58 patients (65.9%) had normal glycemic indexes. Eleven patients (12.5%) had mild, 9 patients (10.2%) had moderate, and 10 patients (11.4%) had severe hyperglycemia. The prevalence of mortality was 5.7% among hyperglycemic patients and 6.8% among normal glycemic pediatrics. There were no statistically significant differences regarding mortality rate (P = 0.499). The mean PRISM score for normal glycemic patients was 7.03 ± 5.18 and for patients with hyperglycemia was 7.36 ± 6.37.

Conclusion:

Hyperglycemia has no significant effects on mortality and PRISM score of pediatrics in PICU, despite of the previous studies. The frequency of hyperglycemia was also 5.7% among the patients admitted in PICU.

Hyperglycaemia in the Newborn Infant. Physiology Verses Pathology

Hyperglycemia is common in newborns requiring intensive care, particularly in preterm infants, in sepsis and following perinatal hypoxia. The clinical significance, and optimal intervention strategy varies with context, but hyperglycaemia is associated with increased mortality and morbidity. The limited evidence for optimal clinical targets mean controversy remains regarding thresholds for intervention, and management strategies. The first consideration in the management of hyperglycaemia must be to ascertain potentially treatable causes. Calculation of the glucose infusion rate (GIR) to insure this is not excessive, is critical but the use of insulin is often helpful in the extremely preterm infant, but is associated with an increased risk of hypoglycaemia. The use of continuous glucose monitoring (CGM) has recently been demonstrated to be helpful in targeting glucose control, and reducing the risk from hypoglycaemia in the preterm infant. Its use in other at risk infants remains to be explored, and further studies are needed to provide a better understanding of the optimal glucose targets for different clinical conditions. In the future the combination of CGM and advances in computer algorithms, to provide intelligent closed loop systems, could allow a safer and more personalized approached to management.

Relationships between Early Nutrition, Illness, and Later Outcomes among Infants Born Preterm with Hyperglycemia

OBJECTIVE

To evaluate the effects of hyperglycemia on body composition and neurodevelopment, and how early nutrition and illness modify these relationships in infants born preterm.

STUDY DESIGN

Prospective data were collected from infants born <32 weeks of gestational age (N = 97), including inpatient days of hyperglycemia (blood glucose >150 mg/dL) and nutrient intake. Body composition was measured at discharge and 4 months' postmenstrual age (PMA). Bayley Scales of Infant Development III (BSID-III) were administered at 12 months' PMA. Linear regression analysis was performed, adjusting for birth gestational age. Associations between hyperglycemia, body composition, and BSID-III were analyzed in models accounting for first-week nutrition and early illness severity via Score for Neonatal Acute Physiology-II.

RESULTS

Mean birth gestational age was 27.8 (SD 2.4) weeks. Hyperglycemia occurred in 48.5% of infants. Hyperglycemia for ≥5 days was negatively associated with fat mass and fat free mass z scores at discharge, and fat free mass z score at 4 months' PMA (P < .05 all). Hyperglycemia for ≥5 days was negatively associated with cognition, language, and motor scores on the BSDI at 12 months (P ≤ .01 all). Associations with body composition and BSID-III were diminished when models included first week nutrition yet remained unchanged when illness severity was included.

CONCLUSIONS

In infants <32 weeks, ≥5 days of hyperglycemia is associated with decreased lean mass at 4 months' PMA and poorer neurodevelopmental outcome at 12 months' PMA. These associations may be mediated by decreased first week nutrition, potentially related to reduced glucose infusion rate for management of hyperglycemia.

Modelling intestinal glucose absorption in premature infants using continuous glucose monitoring data

BACKGROUND

Model-based glycaemic control protocols have shown promise in neonatal intensive care units (NICUs) for reducing both hyperglycaemia and insulin-therapy driven hypoglycaemia. However, current models for the appearance of glucose from enteral feeding are based on values from adult intensive care cohorts. This study aims to determine enteral glucose appearance model parameters more reflective of premature infant physiology.

METHODS

Peaks in CGM data associated with enteral milk feeds in preterm and term infants are used to fit a two compartment gut model. The first compartment describes glucose in the stomach, and the half life of gastric emptying is estimated as 20 min from literature. The second compartment describes glucose in the small intestine, and absorption of glucose into the blood is fit to CGM data. Two infant cohorts from two NICUs are used, and results are compared to appearances derived from data in highly controlled studies in literature.

RESULTS

The average half life across all infants for glucose absorption from the gut to the blood was 50 min. This result was slightly slower than, but of similar magnitude to, results derived from literature. No trends were found with gestational or postnatal age. Breast milk fed infants were found to have a higher absorption constant than formula fed infants, a result which may reflect known differences in gastric emptying for different feed types.

CONCLUSIONS

This paper presents a methodology for estimation of glucose appearance due to enteral feeding, and model parameters suitable for a NICU model-based glycaemic control context.

Safe and effective glycaemic control in premature infants: observational clinical results from the computerised STAR-GRYPHON protocol

OBJECTIVE

Previous studies examine clinical outcomes of insulin therapy in neonatal intensive care units (NICUs), without first developing safe and effective control protocols. This research quantifies the safety and performance of a computerised model-based control algorithmSTAR-GRYPHON (Stochastic TARgeted Glucose Regulation sYstem to Prevent Hyper- and hypO-glycaemia in Neonates).

DESIGN

Retrospective observational study of glycaemic control in very/extremely low birthweight infants treated with insulin from Christchurch Women's Hospital NICU between January 2013 and June 2017. Blood glucose (BG) outcomes and control performance is compared with retrospective data (n=22) and literature.

INTERVENTIONS

Insulin infusion doses were calculated from 3 to 4 hourly BG measurements using a computerised model-based control algorithm, STAR-GRYPHON.

MAIN OUTCOME MEASURES

Mean BG, time in targeted range and incidence of hypoglycaemia.

RESULTS

STAR-GRYPHON (n=35) had lower mean BG concentration (7.0mmol/L vs 7.9 mmol/L), higher %BG within the 4.0-8.0 mmol/L target range (71.1% vs 50.9%) and lower %BG <4.0 mmol/L (0.6% vs 2.1%). There were only 2 BG <2.6 mmol/L (over n=2, 5.5% of patients, 0.03% of all BG outcomes), one of which may be attributed to clinical error. These results show better control to target and lower incidence of hypoglycaemia than most literature results from intensive insulin therapy protocols or study groups in children and infants.

CONCLUSIONS

Model-based protocols can safely and effectively control BG in very premature infants and should be used in future studies to determine the effect of insulin therapy on clinical outcomes.

Assessment of clinical outcome of children with sepsis outside the intensive care unit

In 2016, in order to identify adult patients with sepsis who are likely to have poor outcomes, the Third International Consensus Definitions Task Force introduced a new bedside index, called the quick Sepsis-related Organ Failure Assessment (qSOFA) score. However, these new criteria have not been validated in the pediatric population. In this study, we sought to assess the qSOFA score for children with sepsis, who are being treated outside the pediatric intensive care units. The qSOFA criteria were revised and applied to a study population of 89 pediatric patients with sepsis, admitted in a pediatric tertiary referral center from 2006 to 2016. The analysis of prognostic performance of qSOFA score for the prediction of severe sepsis showed a sensitivity of 46% (95% CI, 27-67%), a specificity of 74% (95% CI, 62-85%), a positive predictive value of 43% (95% CI, 34-52%), and a negative predictive value of 77% (95% CI, 71-82%). The area under ROC curve for qSOFA score ≥ 2 was 0.602 (95% CI 0.492-0.705).Conclusion: The qSOFA score showed a low accuracy to identify children in the pediatric ward at risk for severe sepsis. Clinical tools are needed to facilitate the diagnosis of impending organ dysfunction in pediatric infection outside of the ICU. What is Known: • One of the major challenges for clinicians is to identify and recognize children with sepsis and impending organ dysfunction, in the emergency and in the pediatric department. • In 2016, members of the Sepsis-3 task force proposed qSOFA, an empirically derived score using simple clinical criteria, to assist clinicians in identifying adult patients with sepsis at risk for poor outcome. What is New: • qSOFA demonstrated insufficient clinical value to be recommended as a screening tool for pediatric sepsis outside ICU. • D-dimer level and blood glucose may be useful biomarkers to identify children at risk for severe sepsis.

Model-based glycaemic control: methodology and initial results from neonatal intensive care

Very/extremely premature infants often experience glycaemic dysregulation, resulting in abnormally elevated (hyperglycaemia) or low (hypoglycaemia) blood glucose (BG) concentrations, due to prematurity, stress, and illness. STAR-GRYPHON is a computerised protocol that utilises a model-based insulin sensitivity parameter to directly tailor therapy for individual patients and their changing conditions, unlike other common insulin protocols in this cohort. From January 2013 to January 2015, 13 patients totalling 16 hyperglycaemic control episodes received insulin under STAR-GRYPHON. A significant improvement in control was achieved in comparison to a retrospective cohort, with a 26% absolute improvement in BG within the targeted range and no hypoglycaemia. This improvement was obtained predominantly due to the reduction of hyperglycaemia (%BG>10.0 mmol/l: 5.6 vs. 17.7%, p<0.001), and lowering of the median per-patient BG [6.9 (6.1-7.9) vs. 7.8 (6.6-9.1) mmol/l, p<0.001, Mann-Witney U test]. While cohort-wide control results show good control overall, there is high intra-patient variability in BG behaviour, resulting in overly conservative treatments for some patients. Patient insulin sensitivity differs between and within patients over time, with some patients having stable insulin sensitivity, while others change rapidly. These results demonstrate the trade-off between safety and performance in a highly variable and fragile cohort.

Early postnatal hyperglycaemia is a risk factor for treatment-demanding retinopathy of prematurity

BACKGROUND

To investigate whether neonatal hyperglycaemia in the first postnatal week is associated with treatment-demanding retinopathy of prematurity (ROP).

METHODS

This is a Danish national, retrospective, case-control study of premature infants (birth period 2003-2006). Three national registers were searched, and data were linked through a unique civil registration number. The study sample consisted of 106 cases each matched with two comparison infants. Matching criteria were gestational age (GA) at birth, ROP not registered and born at the same neonatal intensive care unit. Potential 'new' risk factors were analysed in a multivariate logistic regression model, while adjusted for previously recognised risk factors (ie, GA at birth, small for gestational age, multiple birth and male sex).

RESULTS

Hospital records of 310 preterm infants (106 treated; 204 comparison infants) were available. Nutrition in terms of energy (kcal/kg/week) and protein (g/kg/week) given to the preterm infants during the first postnatal week were statistically insignificant between the study groups (Mann-Whitney U test; p=0.165/p=0.163). Early postnatal weight gain between the two study groups was borderline significant (t-test; p=0.047). Hyperglycaemic events (indexed value) were statistically significantly different between the two study groups (Mann-Whitney U test; p<0.001). Hyperglycaemia was a statistically independent risk factor (OR: 1.022; 95% CI 1.002 to 1.042; p=0.031).

CONCLUSION

An independent association was found between the occurrence of hyperglycaemic events during the first postnatal week and later development of treatment-demanding ROP, when adjusted for known risk factors.

Hyperglycemia in Acutely Ill Non-diabetic Children in the Emergency Rooms of 2 Tertiary Hospitals in Lagos, Nigeria

OBJECTIVES

The study aimed to determine the prevalence of hyperglycemia in sick children admitted into the emergency rooms and to investigate its relationship with adverse outcomes.

METHODS

A prospective study involving 2 tertiary hospitals in Lagos. Study subjects included all children aged beyond 1 month. An Accu-Chek Active glucometer was used for the bedside blood glucose determination. Hyperglycemia was defined as blood glucose greater than 7.8 mmol/L.

RESULTS

A total of 1045 patients were recruited with hyperglycemia being recorded in 135 patients (prevalence rate of 12.9%). Mean age of the hyperglycemic patients was 29.0 ± 31.23 months. Prevalence rates of hyperglycemia among the leading diagnoses were 17.4% in acute respiratory tract infections, 11% in malaria, 15.3% in septicemia, 14.9% in gastroenteritis, and 18.2% in burns. Other conditions include sickle cell anemia, meningitis, and malnutrition. Mortality rate was significantly higher overall in hyperglycemic compared with the normoglycemic patients (15.4% vs 8.0%, P = 0.011). With regard to specific diagnoses, significantly higher mortality rates were recorded in hyperglycemic patients with acute respiratory tract infections (28% vs 8%, P = 0.011) and malaria (21.4% vs 5.0%, P = 0.006) than in their normoglycemic counterparts.

CONCLUSIONS

Hyperglycemia is common in ill children admitted to the emergency rooms and is associated with 2 to 4 times higher mortality in common childhood diseases encountered. Blood glucose determination is important in all acutely ill children at presentation. The practice of empirical administration of intravenous glucose in some resource-constrained facilities where blood glucose testing facilities are not readily available should be discouraged.

Insulin kinetics and the Neonatal Intensive Care Insulin-Nutrition-Glucose (NICING) model

BACKGROUND

Models of human glucose-insulin physiology have been developed for a range of uses, with similarly different levels of complexity and accuracy. STAR (Stochastic Targeted) is a model-based approach to glycaemic control. Elevated blood glucose concentrations (hyperglycaemia) are a common complication of stress and prematurity in very premature infants, and have been associated with worsened outcomes and higher mortality. This research identifies and validates the model parameters for model-based glycaemic control in neonatal intensive care.

METHODS

C-peptide, plasma insulin, and BG from a cohort of 41 extremely pre-term (median age 27.2 [26.2-28.7] weeks) and very low birth weight infants (median birth weight 839 [735-1000] g) are used alongside C-peptide kinetic models to identify model parameters associated with insulin kinetics in the NICING (Neonatal Intensive Care Insulin-Nutrition-Glucose) model. A literature analysis is used to determine models of kidney clearance and body fluid compartment volumes. The full, final NICING model is validated by fitting the model to a cohort of 160 glucose, insulin, and nutrition data records from extremely premature infants from two different NICUs (neonatal intensive care units).

RESULTS

Six model parameters related to insulin kinetics were identified. The resulting NICING model is more physiologically descriptive than prior model iterations, including clearance pathways of insulin via the liver and kidney, rather than a lumped parameter. In addition, insulin diffusion between plasma and interstitial spaces is evaluated, with differences in distribution volume taken into consideration for each of these spaces. The NICING model was shown to fit clinical data well, with a low model fit error similar to that of previous model iterations.

CONCLUSIONS

Insulin kinetic parameters have been identified, and the NICING model is presented for glycaemic control neonatal intensive care. The resulting NICING model is more complex and physiologically relevant, with no loss in bedside-identifiability or ability to capture and predict metabolic dynamics.

Hyperglycemia and its association with clinical outcomes in postsurgical neonates and small infants in the intensive care unit

PURPOSE

The aim of the research was to investigate the association between postsurgical hyperglycemia of neonates and small infants (<6months) during their stays in intensive care unit and clinical outcomes.

METHODS

A retrospective study of 180 patients including neonates and small infants (<6months) admitted to pediatric intensive care unit (PICU) after major abdominal and thoracic surgeries from July 2012 to December 2014 was performed. Clinical data including serum glucose levels, surgical procedures, PICU length of stays, total length of hospital stays, systemic infections and wound infections were recorded and analyzed. Surgical diagnosis and Pediatric Risk of Mortality III (PRISM III) score were analyzed as confounding factors.

RESULTS

Maximum glucose values (Gmax) ranged from 4.8 to 32.9mmol/L (median level: 8.4mmol/L). Hyperglycemia was prevalent among this group of patients. 93.3% of them experienced hyperglycemia (>6.1mmol/L) and 20% had severe hyperglycemia (>11.0mmol/L). Both PICU length of stays and total hospital length of stays increased as Gmax increased (P<0.001). This trend was still statistically significant when either surgical diagnosis or PRISM score had been controlled as confounding factors. Death rates and infectious rates were not significantly different among four groups of patients with different Gmax.

CONCLUSIONS

Hyperglycemia was prevalent in postsurgical neonates and small infants in PICU and was associated with increased PICU and hospital stays.

Postoperative Hyperglycemia and 4-Year Neurodevelopmental Outcome in Children Operated for Congenital Heart Disease

OBJECTIVES

To study the long-term neurodevelopmental effects of hyperglycemia in infant bypass surgery for congenital heart disease (CHD).

STUDY DESIGN

Prospective cohort study on neurodevelopmental outcome after infant cardiac bypass surgery.

EXCLUSION CRITERIA

age older than 1 year at first surgery, genetic comorbidity, and birth weight <2000 g. Of 167 eligible infants, follow-up examination at 4 years was completed in 150 children (90%). Intraoperative and postoperative highest and lowest glucose levels within 24 hours after bypass surgery were prospectively collected. Neurodevelopmental outcome at 4 years of age was assessed using standardized IQ tests and the Movement Assessment Battery for Children-second version for motor outcome assessment.

RESULTS

Mean age at surgery was 2.8 months (0.1-10.7 months), 33% of children had an acyanotic CHD and 67% a cyanotic CHD. Glucose levels were elevated (>8 mmol/L) in 21 (14%) children in the first 24 postoperative hours. Glucose levels normalized in all children within 48 hours, 7 children (4%) received insulin infusions. Mean total IQ was within the normal range, but significantly lower than the normal population (92.5 [SD 15.0], P < .001). Higher postoperative glucose levels were related to better cognitive performance in the univariate analysis (P < .03), but not when other risk factors were taken into account. Independent risk factors for adverse outcome were lower socioeconomic status, higher risk adjustment for congenital heart surgery score, and longer duration of intensive care stay.

CONCLUSION

Hyperglycemia is common in the early postoperative course after infant bypass surgery for CHD and normalizes within 48 hours. Hyperglycemia has no adverse effect on long-term neurodevelopmental outcome.

Recurrent hypoinsulinemic hyperglycemia in neonatal rats increases PARP-1 and NF-κB expression and leads to microglial activation in the cerebral cortex

BACKGROUND

Hyperglycemia is a common metabolic problem in extremely low-birth-weight preterm infants. Neonatal hyperglycemia is associated with increased mortality and brain injury. Glucose-mediated oxidative injury may be responsible. Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme involved in DNA repair and cell survival. However, PARP-1 overactivation leads to cell death. NF-κB is coactivated with PARP-1 and regulates microglial activation. The effects of recurrent hyperglycemia on PARP-1/NF-κB expression and microglial activation are not well understood.

METHODS

Rat pups were subjected to recurrent hypoinsulinemic hyperglycemia of 2 h duration twice daily from postnatal (P) day 3-P12 and killed on P13. mRNA and protein expression of PARP-1/NF-κB and their downstream effectors were determined in the cerebral cortex. Microgliosis was determined using CD11 immunohistochemistry.

RESULTS

Recurrent hyperglycemia increased PARP-1 expression confined to the nucleus and without causing PARP-1 overactivation and cell death. NF-κB mRNA expression was increased, while IκB mRNA expression was decreased. inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and neuronal nitric oxide synthase (nNOS) mRNA expressions were decreased. Hyperglycemia significantly increased the number of microglia.

CONCLUSION

Recurrent hyperglycemia in neonatal rats is associated with upregulation of PARP-1 and NF-κB expression and subsequent microgliosis but not neuronal cell death in the cerebral cortex.

Glucocorticoid-Induced Preterm Birth and Neonatal Hyperglycemia Alter Ovine β-Cell Development

Adults born preterm are at increased risk of impaired glucose tolerance and diabetes. Late gestation fetuses exposed to high blood glucose concentration also are at increased risk of impaired glucose tolerance as adults. Preterm babies commonly become hyperglycemic and are thus exposed to high blood glucose concentration at an equivalent stage of pancreatic maturation. It is not known whether preterm birth itself, or complications of prematurity, such as hyperglycemia, alter later pancreatic function. To distinguish these, we made singleton preterm lambs hyperglycemic (HYPER) for 12 days after birth with a dextrose infusion and compared them with vehicle-treated preterm and term controls and with HYPER lambs made normoglycemic with an insulin infusion. Preterm birth reduced β-cell mass, apparent by 4 weeks after term and persisting to adulthood (12 mo), and was associated with reduced insulin secretion at 4 months (juvenile) and reduced insulin mRNA expression in adulthood. Hyperglycemia in preterm lambs further down-regulated key pancreatic gene expression in adulthood. These findings indicate that reduced β-cell mass after preterm birth may be an important factor in increased risk of diabetes after preterm birth and may be exacerbated by postnatal hyperglycemia.

Low phosphatemia in extremely low birth weight neonates: A risk factor for hyperglycemia?

BACKGROUND & AIMS

Hyperglycemia occurs in more than half of the extremely low birth weight (ELBW) neonates during the first weeks of life, and is correlated with an increased risk of morbi-mortality. Hypophosphatemia is another frequent metabolic disorder in this population. Data from animal, adult studies and clinical observation suggest that hypophosphatemia could induce glucose intolerance. Our aim was to determine whether a low phosphatemia is associated with hyperglycemia in ELBW neonates.

METHODS

This observational study included ELBW infants admitted in a tertiary neonatal care center (2010-2011). According to the center's policy, they received parenteral nutrition from birth and human milk from day 1. Phosphatemia and glycemia were measured routinely during parenteral nutrition. Hyperglycemia was defined by two consecutives values >8.3 mmol/L (150 mg/dL). Statistical analysis used a joint model combining a mixed-effects and a survival submodels to measure the association between phosphate and hyperglycemia.

RESULTS

The study included 148 patients. Mean gestational (Standard Deviation) age was 27.3 (1.6) weeks; mean birth weight was 803 (124) grams; 57% presented hyperglycemia. The multivariate joint model showed that the hazard of hyperglycemia at a given time was multiplied by 3 for each 0.41 mmol/L decrease of phosphate level at this time (p = 0.002) and by 3.85 for the same decreased of phosphate the day before (p = 0.0015).

CONCLUSION

To our knowledge, this is the first study suggesting that low phosphatemia can be associated with hyperglycemia in ELBW neonates. Further studies will have to demonstrate whether better control of phosphatemia could help in preventing hyperglycemia.

A C-Peptide-Based Model of Pancreatic Insulin Secretion in Extremely Preterm Neonates in Intensive Care

BACKGROUND

Model-based glycemic control relies on sufficiency of underlying models to describe underlying patient physiology. In particular, very preterm infant glucose-insulin metabolism can differ significantly from adults, and is relatively unstudied. In this study, C-peptide concentrations are used to develop insulin-secretion models for the purposes of glycemic control in neonatal intensive care.

METHODS

Plasma C-peptide, insulin, and blood glucose concentrations (BGC) were retrospectively analyzed from a cohort of 41 hyperglycemic very preterm (median age 27.2 [26.2-28.7] weeks) and very low birth-weight infants (median birth weight 839 [735-1000] g). A 2-compartment model of C-peptide kinetics was used to estimate insulin secretion. Insulin secretion was examined with respect to nutritional intake, exogenous and plasma insulin concentration, and BGC.

RESULTS

Insulin secretion was found to be highly variable between patients and over time, and could not be modeled with respect to age, weight, or protein or dextrose intake. In 13 of 54 samples exogenous insulin was being administered, and insulin secretion was lower. However, low data numbers make this result inconclusive. Insulin secretion was found to increase with BG, with a stronger association in female infants than males (R(2) = .51 vs R(2) = .13, and R(2) = .26 for the combined cohort).

CONCLUSIONS

A sex-based insulin secretion model was created and incorporated into a model-based glycemic control framework. Nutritional intake did not predict insulin secretion, indicating that insulin secretion is a complex function of a number of metabolic factors.

Peripheral insulin resistance and impaired insulin signaling contribute to abnormal glucose metabolism in preterm baboons

Premature infants develop hyperglycemia shortly after birth, increasing their morbidity and death. Surviving infants have increased incidence of diabetes as young adults. Our understanding of the biological basis for the insulin resistance of prematurity and developmental regulation of glucose production remains fragmentary. The objective of this study was to examine maturational differences in insulin sensitivity and the insulin-signaling pathway in skeletal muscle and adipose tissue of 30 neonatal baboons using the euglycemic hyperinsulinemic clamp. Preterm baboons (67% gestation) had reduced peripheral insulin sensitivity shortly after birth (M value 12.5 ± 1.5 vs 21.8 ± 4.4 mg/kg · min in term baboons) and at 2 weeks of age (M value 12.8 ± 2.6 vs 16.3 ± 4.2, respectively). Insulin increased Akt phosphorylation, but these responses were significantly lower in preterm baboons during the first week of life (3.2-fold vs 9.8-fold). Preterm baboons had lower glucose transporter-1 protein content throughout the first 2 weeks of life (8%-12% of term). In preterm baboons, serum free fatty acids (FFAs) did not decrease in response to insulin, whereas FFAs decreased by greater than 80% in term baboons; the impaired suppression of FFAs in the preterm animals was paired with a decreased glucose transporter-4 protein content in adipose tissue. In conclusion, peripheral insulin resistance and impaired non-insulin-dependent glucose uptake play an important role in hyperglycemia of prematurity. Impaired insulin signaling (reduced Akt) contributes to the defect in insulin-stimulated glucose disposal. Counterregulatory hormones are not major contributors.

Developmental regulation of key gluconeogenic molecules in nonhuman primates

Aberrant glucose regulation is common in preterm and full‐term neonates leading to short and long‐term morbidity/mortality; however, glucose metabolism in this population is understudied. The aim of this study was to investigate developmental differences in hepatic gluconeogenic pathways in fetal/newborn baboons. Fifteen fetal baboons were delivered at 125 day (d) gestational age (GA), 140d GA, and 175d GA (term = 185d GA) via cesarean section and sacrificed at birth. Term and healthy adult baboons were used as controls. Protein content and gene expression of key hepatic gluconeogenic molecules were measured: cytosolic and mitochondrial phosphoenolpyruvate carboxykinase (PEPCK‐C and PEPCK‐M), glucose‐6‐phosphatase‐alpha (G6Pase‐α), G6Pase‐β, fructose‐1,6‐bisphosphatase (FBPase), and forkhead box‐O1 (FOXO1). Protein content of PEPCK‐M increased with advancing gestation in fetal baboons (9.6 fold increase from 125d GA to 175d GA, P < 0.001). PEPCK‐C gene expression was consistent with these developmental differences. Phosphorylation of FOXO1 was significantly lower in preterm fetal baboons compared to adults, and gene expression of FOXO1 was lower in all neonates when compared to adults (10% and 62% of adults respectively, P < 0.05). The FOXO1 target gene G6Pase expression was higher in preterm animals compared to term animals. No significant differences were found in G6Pase‐α, G6Pase‐β, FOXO1, and FBPase during fetal development. In conclusion, significant developmental differences are found in hepatic gluconeogenic molecules in fetal and neonatal baboons, which may impact the responses to insulin during the neonatal period. Further studies under insulin‐stimulated conditions are required to understand the physiologic impact of these maturational differences.

Significant developmental differences were found in several hepatic gluconeogenic molecules. In particular, phosphorylated FOXO1 was significantly reduced in the liver of premature fetal baboons compared to adults and may contribute the increased incidence of hyperglycemia seen in prematurity. In addition, PEPCK increased with advancing gestational age and may play a key role in glucose regulation during the newborn period.

A prospective study on hyperglycemia and retinopathy of prematurity

OBJECTIVE

Retinopathy of prematurity (ROP) constitutes a significant morbidity in premature infants that can lead to blindness. Multiple retrospective studies have identified neonatal hyperglycemia as a risk for developing ROP. However, in the absence of any reported prospective study, it is not clear whether hyperglycemia is associated with ROP independent of the commonly associated comorbidities. The objective of this study was to investigate whether hyperglycemia in premature infants is independently associated with ROP.

STUDY DESIGN

Premature infants (<1500 g or⩽32 weeks gestational age) were enrolled in a prospective longitudinal cohort study. All demographic, clinical and laboratory data were collected. Bedside whole-blood glucose concentration was measured every 8 h daily for 7 days. For any glucose reading<50 or>150 mg dl(-1), serum sample was sent to the laboratory for confirmation. Hyperglycemia was defined as any blood glucose level⩾150 mg dl(-1). ROP patients were compared with non-ROP patients in a bivariate analysis. Variables significantly associated with ROP were studied in a logistic regression model.

RESULT

A total of 65 patients were enrolled with gestational age 31.1±1.2 weeks and birth weight 1385±226 g. Thirty-one patients (48%) were identified with hyperglycemia. On eye examination, 19 cases (29.2%) had ROP (13 with stage 1, 4 with stage 2 and 2 with stage 3). There were more cases of ROP in the hyperglycemia group compared with the euglycemia group (45% vs 15%, P=0.007). Patients who developed ROP had significantly higher maximum and average glucose concentrations when compared with non-ROP patients. Multiple factors have been associated with ROP on bivariate analysis, including gestational age, exposure to oxygen, respiratory support and poor weight gain. However, in a logistic regression model including all significant variables, average blood glucose in the first week of life was the factor independently associated with ROP with an odds ratio of: 1.77 (95% confidence interval: 1.08 to 2.86), P=0.024.

CONCLUSION

In a cohort of premature infants, elevated average blood glucose concentrations in the first week of life is independently associated with the development of ROP.

Hyperglycemia in critically ill children

OBJECTIVES

To determine the incidence and study association of hyperglycemia with outcome of critically ill children.

SETTING AND DESIGN

This was a prospective observational study conducted in eight bedded pediatric intensive care unit (PICU) of a tertiary care hospital.

MATERIALS AND METHODS

One hundred and one critically ill non-diabetic children between ages of 1 month to 16 years were studied from the day of admission till discharge or death. Serial blood sugars were determined first at admission, thereafter every 12 hourly in all children. Blood glucose level above 126 mg/dl (>7 mmol/dl) was considered as hyperglycemia. Children with hyperglycemia were followed 6 hourly till blood glucose fell below 126 mg/dl. Hyper and non-hyperglycemic children were compared with respect to length of stay, mechanical ventilation, use of inotrops and final outcome. Survivors and non-survivors were compared in relation to admission blood glucose, peak blood glucose level and duration of hyperglycemia.

RESULTS

Seventy (69.3%) children had hyperglycemia. Requirement of ventilation [(23) 32.9% vs.(3) 9.7%], requirement of inotropic support [(27) 38.6% vs.(5) 16.1%], Mean length of stay in PICU (7.91 ± 5.01 vs. 5.58 ± 1.95 days) and mortality (28.6% vs. 3.2%) among hyperglycemic children was significantly higher (P < 0.05) than that of non-hyperglycemic. Logistic regression analysis showed Peak blood glucose level and duration of hyperglycemia has independent association with increased risk of death.

CONCLUSION

Incidence of hyperglycemia is high in critically ill children and it is associated with high morbidity and mortality.

Hyperglycemia as a risk factor for the development of retinopathy of prematurity

BACKGROUND

Hyperglycemia has recently been described as a risk factor for the development of retinopathy of prematurity (ROP), a proliferative vascular disease of the retina that primarily affects premature infants. This study was to evaluate the relationship of hyperglycemia and the development of ROP in premature infants less than 32 weeks gestation.

METHODS

This was a retrospective cohort study of all infants less than 32 weeks gestation from 2003-2007 who survived to discharge in our NICU. Demographic data including birthweight, gestational age, Apgar scores, method of delivery, antenatal steroid use, neonatal steroid use, and size for gestational age was collected for each infant. Episodes of sepsis, grade of intraventricular hemorrhage, presence of a patent ductus arteriosus, number of days on the ventilator, and stage of necrotizing enterocolitis were assessed as well as days of hyperglycemia, defined as number of days with whole blood glucose > 150 mg/dl. In addition, the highest stage of ROP was recorded for each infant. A Student's two tailed t-test or Fisher's exact test was performed to identify significant clinical risk factors associated with the development of ROP. From this univariate analysis, a multiple logistic regression was performed to determine the effect of hyperglycemia on the development of ROP, adjusting for significant clinical risk factors. Statistical analysis was performed using SAS v.9.2.

RESULTS

Univariate analysis demonstrated that infants with ROP were of lower birthweight and gestational age, and were affected by a patent ductus arteriosus, neonatal sepsis, intraventricular hemorrhage, have significant lung disease and received postnatal glucocorticoid therapy. Infants with ROP experienced more days with hyperglycemia (7 vs. 2, p = < 0.0001). Using multiple logistic regression analysis to compare no ROP vs. all stages of ROP, gestational age (OR 0.745, 95% CI [0.634, 0.877], p = 0.0004), mean days of hyperglycemia (OR 1.073, 95% CI [1.004, 1.146], p = 0.04), and mean days receiving mechanical ventilation (OR 1.012, 95% CI [1.000, 1.025], p = 0.05) remained significantly associated with ROP after adjusting for other risk factors.

CONCLUSION

Our data suggests that hyperglycemia is associated with the development of ROP in premature infants.

Hyperglycemia and its association with clinical outcomes for patients in the pediatric intensive care unit after abdominal surgery

PURPOSE

We investigated the incidence of hyperglycemia of patients in the pediatric intensive care unit (PICU) after receiving abdominal surgery and its association with clinical outcomes.

METHODS

A retrospective review was performed from November 1, 2010 to November 1, 2011 on all PICU admissions after abdominal surgery. Maximum serum glucose concentrations (Gmax) in PICU, PICU length of stay, total hospital length of stay, deep and systemic infection, wound infection and mortality rates were recorded and analyzed.

RESULTS

A total of 193 children met the inclusion criteria of our research. Maximum glucose levels ranged from 55.7 mg/dL to 415.9 mg/dL (median: 132 mg/dL). Hyperglycemia in PICU was prevalent, with 125 (64.8%) patients having Gmax >110 mg/dL during their PICU stay and 35 (18.8%) having Gmax >200 mg/dL. Average PICU length of stay and total hospital length of stay grew as the maximum glucose levels rose among the four plasma glycemic ranges. The highest serum glucose range patient group also had the highest wound infection rates (14.3% and 11.4%).

CONCLUSIONS

Hyperglycemia was prevalent among patients after major abdominal surgery in PICU and was correlated with increased PICU length of stay, total hospital length of stay. Appropriate glycemic control may improve clinical outcomes for this group of patients.

Hyperglycemia increases the risk of death in extremely preterm baboons

BACKGROUND

Transient neonatal hyperglycemia (HG) has been reported in up to 80% of extremely preterm human infants. We hypothesize that severe HG is associated with increased morbidity and mortality in preterm baboons.

METHODS

Sixty-six baboons born at 67% of gestation were studied. HG was defined as serum glucose level ≥150 mg/dl during the first week of life. Animals were stratified into two groups: severe HG (≥8 events) and nonsevere HG (<8 events).

RESULTS

HG developed in 65 of the 66 (98%) baboons that were included. A total of 3,386 glucose measurements were obtained. The mean serum glucose level was 159 ± 69 mg/dl for the severe HG group and 130 ± 48 mg/dl for the nonsevere HG group during the first week of life. No differences were found in gender, birth weight, sepsis, patent ductus arteriosus, or oxygenation/ventilation indexes between groups. Severe HG was associated with early death even after controlling for sepsis, postnatal steroid exposure, and catecholamine utilization.

CONCLUSION

HG is common in preterm baboons and is not associated with short-term morbidity. Severe HG occurring in the first week of life is associated with early death in preterm baboons.

Common endocrine issues in the pediatric intensive care unit

Thyroid hormone is central to normal development and metabolism. Abnormalities in thyroid function in North America often arise from autoimmune diseases, but they rarely present as critical illness. Severe deficiency or excess of thyroid hormone both represent life-threatening disease, which must be treated expeditiously and thoroughly. Such deficiencies must be considered, because presentation may be nonspecific.

Abnormalities in glucose homeostasis in critically ill children

OBJECTIVES

To study the prevalence of hyperglycemia (blood glucose >126 mg/dL [>7 mmol/L]) in critically ill children older than 1 month in the first week of PICU stay and to determine its effect on mortality, organ dysfunction, and the length of PICU stay. We also determined the prevalence of glucose variability and hypoglycemia and studied their effect on mortality and morbidity.

DESIGN

Prospective, observational cohort study.

SETTING

PICU of a tertiary care hospital.

PATIENTS

Children admitted to the PICU older than 1 month of age (January 2009 to June 2010).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Blood glucose values, clinical and laboratory data to calculate Pediatric Index of Mortality-2 and Pediatric Logistic Organ Dysfunction scores, caloric and carbohydrate intake, vasoactive drugs, and steroid and insulin usage for upto 7 days were recorded. Out of 170 critically ill children admitted to the PICU, hyperglycemia (blood glucose >126 mg/dL [7 mmol/L]) was observed in 78.24% children (95% confidence interval 72-84.4). On adjusted analysis, blood glucose level >180 mg/dL (10 mmol/L) was associated with increased mortality. Blood glucose >126 mg/dL (7 mmol/L) was not associated with mortality or PICU length of stay but was associated with multiple organ dysfunction. Hypoglycemia and glucose variability also occurred frequently in critically ill children; these were associated with occurrence of multiple organ failure.

CONCLUSIONS

Hyperglycemia (blood glucose >126 mg/dL [7 mmol/L]) is common in critically ill children, and values >180 mg/dL (10 mmol/L) are associated with mortality. We also noted that hyperglycemia, hypoglycemia (blood glucose <40 mg/dL [2.2 mmol/L]), and glucose variability were associated with multiple organ dysfunction.

The ontogeny of the endocrine pancreas in the fetal/newborn baboon

Erratic regulation of glucose metabolism including hyperglycemia is a common condition in premature infants and is associated with increased morbidity and mortality. The objective of this study was to examine histological and ultrastructural differences in the endocrine pancreas in fetal (throughout gestation) and neonatal baboons. Twelve fetal baboons were delivered at 125 days (d) gestational age (GA), 140d GA, or 175d GA. Eight animals were delivered at term (185d GA); half were fed for 5 days. Seventy-three nondiabetic adult baboons were used for comparison. Pancreatic tissue was studied using light microscopy, confocal imaging, and electron microscopy. The fetal and neonatal endocrine pancreas islet architecture became more organized as GA advanced. The percent areas of α-β-δ-cell type were similar within each fetal and newborn GA (NS) but were higher than the adults (P<0.05) regardless of GA. The ratio of β cells within the islet (whole and core) increased with gestation (P<0.01). Neonatal baboons, which survived for 5 days (feeding), had a 2.5-fold increase in pancreas weight compared with their counterparts killed at birth (P=0.01). Endocrine cells were also found in exocrine ductal and acinar cells in 125, 140 and 175d GA fetuses. Subpopulation of tissue that coexpressed trypsin and glucagon/insulin shows the presence of cells with mixed endo-exocrine lineage in fetuses. In summary, the fetal endocrine pancreas has no prevalence of a α-β-δ-cell type with larger endocrine cell percent areas than adults. Cells with mixed endocrine/exocrine phenotype occur during fetal development. Developmental differences may play a role in glucose homeostasis during the neonatal period and may have long-term implications.

Reduction in hypoglycemic events in critically ill patients on continuous insulin following implementation of a treatment guideline

BACKGROUND

Hyperglycemia is common in critically ill children and appears to be associated with poor outcomes. However, the incidence of hypoglycemia while attempting glycemic control using an insulin infusion may be as high as 25% and hypoglycemia may be an independent risk factor for mortality in critically ill children.

METHODS

An improvement team developed a guideline for initiation and maintenance of insulin infusions for hyperglycemia in critically ill, nondiabetic patients in the pediatric intensive care unit. The guideline included an insulin infusion algorithm that provided an initiating dose, titration instructions, and discontinuation parameters. Guideline recommendations addressed the frequency of bedside blood glucose monitoring and management of symptomatic hypoglycemia while on insulin infusion. The guideline was implemented in late January 2007 and revised in September 2007.

RESULTS

Hypoglycemic events in at-risk patients decreased significantly following implementation of the guideline, from 36% to 3%, despite an increase in the total number of patient days on insulin infusion. The average days between hypoglycemic events increased from 21 to 186.

CONCLUSIONS

Implementation of a guideline to manage critical illness hyperglycemia in nondiabetic, critically ill pediatric patients resulted in a reduction in hypoglycemic events and a sustained increase in the days between such events.

Efficacy and safety of a tight glucose control protocol in critically ill term neonates

BACKGROUND

A large single-center randomized trial showed that treating hyperglycemia in critically ill children improved outcome, despite an increased incidence of hypoglycemia, especially in infants.

OBJECTIVES

We evaluated the efficacy and incidence of hypoglycemia using a tight glucose protocol in critically ill term neonates.

METHODS

Term hyperglycemic (>8 mmol·l(-1); >144 mg·dl(-1)) neonates treated with a tight glucose protocol during a 3.5-year period in a tertiary pediatric intensive care unit were retrospectively analyzed.

RESULTS

Seventy-three term hyperglycemic neonates [age 0 days (0-6), weight 3.2 ± 0.8 kg, PRISM 16 (11-20)] were included for analysis. Eighteen neonates died (25%). The initial mean (range) glucose level was 11.1 mmol·l(-1) [9.6-15.2; 200 mg·dl(-1) (173-274)], and normoglycemia (<8 mmol·l(-1); <144 mg·dl(-1)) was reached within 5.3 h (1-25) with an overall treatment duration of 27 h (10-57). Seven hypoglycemic incidents (5 times ≤2.2 mmol·l(-1); 40 mg·dl(-1), and 2 times <1.7 mmol·l(-1); 31 mg·dl(-1)) occurred in 5 (6.7%) infants, without severe clinical signs. Three hypoglycemic incidents were directly explained due to a protocol violation. One hypoglycemic incident occurred with the onset of sepsis, while no apparent cause was identified for three hypoglycemic incidents.

CONCLUSIONS

Our glucose protocol was effective, but hypoglycemia occurred more frequently than in older children reported previously. Potential differences in glucose and insulin metabolism in term neonates appear to justify additional safety approaches, while awaiting further studies assessing the benefits of tight glucose protocols in this population. Meanwhile, we have decreased the initial insulin starting doses in our protocol.

Modeling the glucose regulatory system in extreme preterm infants

BACKGROUND

Premature infants represent a significant proportion of the neonatal intensive care population. Blood glucose homeostasis in this group is often disturbed by immaturity of endogenous regulatory systems and the stress of their condition. Hypo- and hyperglycemia are frequently reported in very low birth weight infants, and more mature infants often experience low levels of glycemia. A model capturing the unique fundamental dynamics of the neonatal glucose regulatory system could be used to develop better blood glucose control methods.

METHODS

A metabolic system model is adapted from adult critical care to the unique physiological case of the neonate. Integral-based fitting methods were used to identify time-varying insulin sensitivity and non-insulin mediated glucose uptake profiles. The clinically important predictive ability of the model was assessed by assuming insulin sensitivity was constant over prediction intervals of 1, 2 and 4h forward and comparing model-simulated versus actual clinical glucose values for all recorded interventions. The clinical data included 1091 glucose measurements over 3567 total patient hours, along with all associated insulin and nutritional infusion data, for N=25 total cases. Ethics approval was obtained from the Upper South A Regional Ethics Committee for this study.

RESULTS

The identified model had a median absolute percentage error of 2.4% [IQR: 0.9-4.8%] between model-fitted and clinical glucose values. Median absolute prediction errors at 1-, 2- and 4-h intervals were 5.2% [IQR: 2.5-10.3%], 9.4% [IQR: 4.5-18.4%] and 13.6% [IQR: 6.3-27.6%] respectively.

CONCLUSIONS

The model accurately captures and predicts the fundamental dynamic behaviors of the neonatal metabolism well enough for effective clinical decision support in glycemic control. The adaptation from adult to a neonatal case is based on the data from the literature. Low prediction errors and very low fitting errors indicate that the fundamental dynamics of glucose metabolism in both premature neonates and critical care adults can be described by similar mathematical models.

Development of blood glucose control for extremely premature infants

Extremely premature neonates often experience hyperglycaemia, which has been linked to increased mortality and worsened outcomes. Insulin therapy can assist in controlling blood glucose levels and promoting needed growth. This study presents the development of a model-based stochastic targeted controller designed to adapt insulin infusion rates to match the unique and changing metabolic state and control parameters of the neonate. Long-term usage of targeted BG control requires successfully forecasting variations in neonatal metabolic state, accounting for differences in clinical practices between units, and demonstrating robustness to errors that can occur in everyday clinical usage. Simulation studies were used to evaluate controller ability to target several common BG ranges and evaluate controller sensitivity to missed BG measurements and delays in control interventions on a virtual patient cohort of 25 infants developed from retrospective data. Initial clinical pilot trials indicated model performance matched expected performance from simulations. Stochastic targeted glucose control developed using validated patient-specific virtual trials can yield effective protocols for this cohort. Long-term trials show fundamental success, however clinical interface design appears as a critical factor to ensuring good compliance and thus good control.

Hyperglycaemia in preterm neonates: what to know, what to do

Neonatal hyperglycaemia is a frequent complication in VLBW infants during the first week of life. The more common causes include high glucose intake, stress situations such as sepsis, NEC, and surgical treatments, as well as the administration of vasoactive drugs and methylxanthines. The appropriate definition is unclear. Hyperglycaemia has been associated with increased mortality and major morbidities. There have been insufficient randomized clinical trials to help in clarifying which infants should be treated, and there are insufficient data on the pharmacokinetics of insulin in these vulnerable patients.

Prevalence and determinants of hyperglycemia in very low birth weight infants: cohort analyses of the NIRTURE study

OBJECTIVES

To investigate the prevalence and determinants of hyperglycemia in the preterm population, as part of the Neonatal Insulin Therapy in Europe (NIRTURE) Trial.

STUDY DESIGN

We conducted prospective cohort analyses of continuous glucose monitoring data from control infants participating in an international randomized controlled trial. Data were collected from 188 very low birth weight infants (<1500 g).

RESULTS

In the first week of life, 80% of infants had evidence of glucose levels >8 mmol/L, and 32% had glucose levels >10 mmol/L >10% of the time. Independent risk factors for hyperglycemia included increasing prematurity, small size at birth, use of inotropes, lipid infusions, and sepsis. There was a lack of association between rate of dextrose infused and risk of hyperglycemia.

CONCLUSION

The prevalence of hyperglycemia in the very low birth weight infant is high, with marked variability in prevalence between infants, not simply related to rates of glucose infused, but to other potentially modifiable risk factors.

Glucose variability and survival in critically ill children: allostasis or harm?

OBJECTIVES

To assess whether individual blood glucose variability in critically ill children is associated with increased mortality and to define the temporal patterns of blood glucose variability during critical illness in children.

DESIGN

Retrospective cohort study.

SETTING

A 20-bed pediatric intensive care unit in a children's hospital.

PATIENTS

Patients aged 0-20 yrs and with at least 12 blood glucose measurements taken within the first 72 hrs of pediatric intensive care unit admission.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 101 eligible patients had 3,144 measured blood glucose concentrations with 16% mortality. Nonsurvivors had higher median blood glucose concentrations (129 mg/dL vs. 118 mg/dL, p < .01), more hyperglycemia (blood glucose >200 mg/dL) (88% vs. 59%, p < .05), and more hypoglycemia (blood glucose <60 mg/dL) (56% vs. 15%, p < .01) than survivors. The mean blood glucose range (257 mg/dL vs. 185 mg/dL, p < .01) and the blood glucose variability (63 mg/dL vs. 45 mg/dL, p = .02) were greater in nonsurvivors compared with survivors. Blood glucose variability tertiles were proportionately associated with increasing mortality: 6% vs. 15% vs. 27% (p = .07). Compared with survivors, daily blood glucose variability was significantly higher in nonsurvivors during the first 48 hrs of admission and after 1 wk of admission. After controlling for confounders, individual blood glucose variability was associated with higher pediatric intensive care unit mortality for each mg/dL of blood glucose concentration (adjusted odds ratio, 1.03; 95% confidence interval, 1.01-1.05).

CONCLUSIONS

Glucose variability is common in critically ill children and is associated with increased mortality. Whereas early alterations in blood glucose may represent allostasis, later fluctuations in blood glucose may represent an alteration of autoregulation with resulting higher mortality. Control of variability may need to be incorporated into glycemic control regimens.

Nutritional support of the pediatric trauma patient

Of all the interventions available to aid recovery of the injured child, few have the power of proper nutritional support. Healing after trauma depends not only on restoration of oxygen delivery, but on "substrate delivery," or provision of calories to support metabolic power and specific nutrients to allow rebuilding of injured tissue. Failure to deliver adequate substrate to the cells is revealed as another form of shock. Nutritional interventions after trauma are most effective when informed by the specific ways that children diverge physiologically (metabolic rate, biomechanics, physiological response to trauma) from adults. This review describes these responses and outlines a general strategy for safely delivering energy and specific substrates to protect and heal injured children, regardless of body size and type of injury.

Glucose dysregulation and neurological injury biomarkers in critically ill children

CONTEXT

Targeting normoglycemia with intensive insulin therapy (IIT) improved short-term outcome of pediatric intensive care unit (PICU) patients but increased the incidence of hypoglycemia. Both hyperglycemia and hypoglycemia may adversely affect the developing brain.

OBJECTIVE

We studied the impact of targeting normoglycemia with IIT on brain injury markers.

DESIGN

This is a preplanned analysis of PICU patients included in a randomized controlled study.

SETTING

The study was conducted at a university hospital PICU.

PATIENTS

Seven hundred PICU patients participated.

INTERVENTIONS

Patients were assigned to IIT targeting normal-for-age fasting blood glucose levels or insulin infusion only to prevent excessive hyperglycemia.

MAIN OUTCOME MEASURES

Serum S100B and neuron-specific enolase (NSE), biomarkers of astrocytic and neuronal damage, respectively, were measured on fixed days (n = 700) and in a nested case-control design before and after hypoglycemia (n = 126).

RESULTS

Admission levels of S100B and NSE differed according to diagnosis and illness severity (P < 0.0001). IIT did not affect the time course of these markers. Patients experiencing hypoglycemia in PICU had higher S100B and NSE from admission onward than those without hypoglycemia. In the nested case-control study, both markers decreased after hypoglycemia (P = 0.001 and P = 0.009), unlike in the controls on matched days.

CONCLUSIONS

IIT in PICU did not evoke neurological damage detectable by circulating S100B and NSE, despite increased incidence of hypoglycemia. Elevated markers in patients with hypoglycemia were not caused by hypoglycemia itself but rather reflect an increased incidence of hypoglycemia in the most severely ill. This hypoglycemia risk appears difficult to capture by classical illness severity scores.

'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 ontogeny of insulin signaling in the preterm baboon model

Hyperglycemia, a prevalent condition in premature infants, is thought to be a consequence of incomplete suppression of endogenous glucose production and reduced insulin-stimulated glucose disposal in peripheral tissues. However, the molecular basis for these conditions remains unclear. To test the hypothesis that the insulin transduction pathway is underdeveloped with prematurity, fetal baboons were delivered, anesthetized, and euthanized at 125 d gestational age (GA), 140 d GA, or near term at 175 d GA. Vastus lateralis muscle and liver tissues were obtained, and protein content of insulin signaling molecules [insulin receptor (IR)-beta, IR substate-1, p85 subunit of phosphatidylinositol 3-kinase, Akt, and AS160] and glucose transporters (GLUT)-1 and GLUT4 was measured by Western blotting. Muscle from 125 d GA baboons had markedly reduced GLUT1 protein content (16% of 140 d GA and 9% of 175 d GA fetuses). GLUT4 and AS160 also were severely reduced in 125 d GA fetal muscle (43% of 175 d GA and 35% of 175 d GA, respectively). In contrast, the protein content of IR-beta, IR substate-1, and Akt was elevated by 1.7-, 5.2-, and 1.9-fold, respectively, in muscle from 125 d GA baboons when compared with 175 d GA fetuses. No differences were found in the content of insulin signaling proteins in liver. In conclusion, significant gestational differences exist in the protein content of several insulin signaling proteins in the muscle of fetal baboons. Reduced muscle content of key glucose transport-regulating proteins (GLUT1, GLUT4, AS160) could play a role in the pathogenesis of neonatal hyperglycemia and reduced insulin-stimulated glucose disposal.