Hyperglycemia and pediatric neurosurgery Filho EM et al. Table 1 - Glucose levels according to surgical diagnosis. Diagnosis Ventriculoperitoneal shunting Craniostenosis Supratentorial brain tumors Infratentorial brain tumor Craniotomy for craniofacial dysostosis Spinal arthrodesis Epilepsy surgery Brain revascularization for arteriopathy Spinal cord tumors 135.4¡66.5 159.2¡69.9 160.5¡83.3 131.2¡30.8 161.8¡39.2 149.8¡61.8 154.3¡41.1 148¡28.3 128.3¡30.1 *Mean ¡ Standard Deviation (mg/dL). N/E – Blood glucose measurement not evaluated due to the small number of samples. CLINICS 2011;66(9):1637-1640 133.6¡38.5 150.4¡64.2 163.3¡47.9 151¡44.7 152.7¡14.2 238¡172.5 138¡9.9 N/E N/E 117.9¡23.6 118¡39.9 131¡31.9 126.1¡36.9 155.1¡42.3 112.2¡13.1 110.9¡11.9 N/E N/E Glucose level at admission * Highest glucose level in 24 hours * Mean glucose level * DISCUSSION To the best of our knowledge, the present study is the first to analyze the effects and the incidence of hyperglycemia in a pediatric neurosurgery environment. The highest glucose levels were found in patients that underwent surgery for craniosynostosis, supratentorial tumor resection, and cra- niotomies; these procedures are more likely to involve longer surgical times and higher incidence of complications, such as bleeding and infection. These higher incidences of complications increase the risk of hyperglycemia. Univariate analysis indicated an association between hyperglycemia and prolonged duration of stay in the PICU. However, no association was found between hyper- glycemia and the total duration of hospital stay or the length of mechanical ventilation time required. Multivariate analysis indicated no statistically relevant associations between hyperglycemia and any of the outcomes. The occurrence of severe hyperglycemia (above 300 mg/dL) was rare. Hyperglycemia is common in critical illness as a consequence of organic stress and counter-regulatory hormones and is typically interpreted as a secondary event in critical care. Several studies have tried to identify an association between hyperglycemia and a worse prognosis in children, but their findings should be interpreted as markers of severe illness. As the patient’s condition improves, it is likely that their glucose levels will revert to the normal range. As a secondary event, patients with other complications that may affect glucose levels, either directly or indirectly, such as fever, infection or bleeding, are more likely to develop hyperglycemia and, consequently, worse outcomes such as a prolonged ICU stay. Such factors may explain why hyperglycemia was found to be associated with a prolonged stay in the PICU in the univariate but not in the multivariate analysis. Up to 50% of pediatric patients who undergo neuro- surgeries may develop several postoperative complica- tions,8 and hyperglycemia is an important event that may impact on their clinical course. Stress hyperglycemia is associated with insulin resistance and frequently affects adults and children. Some of the factors that may contribute to stress hyperglycemia are high glucose infusion rates, the increase in the production of endogen- ous glucose due to action of the counter-regulatory hormones (cortisol, glucagon, and catecholamine), and changes in glucose transport.9 Changes in insulin counter-regulatory hormones due to surgical stress have not been clearly defined; therefore, the 1638 highest glucose level within the first 24 hours following surgery was analyzed separately from the glucose level at admission. There was a progressive reduction in glucose levels in all surgical groups during the course of hospita- lization. Mild hyperglycemia was identified and its rapid progression to normal levels may be explained by the low preoperative morbidity of the population studied, as most procedures were elective and performed in patients with a low anesthetic risk. According to this hypothesis, the patients were more likely not to present the main consequences of severe hyperglycemia, such as osmotic diuresis, dehydration, and metabolic disorders. When considering the results of the entire study population, hyperglycemia was not severe enough in this scenario to cause adverse effects and outcomes related to this metabolic disorder. It was not possible to evaluate the correlation between hyperglycemia and mortality because only two deaths occurred during the study. Nearly 59% of the patients received one or more doses of systemic corticosteroids during surgery or their ICU stay, while 93% of the patients who underwent brain tumor surgeries received them. There are no current recommendations regarding the routine postoperative use of corticosteroids, which are administered with the aim of reducing the brain edema associated with resection. Nevertheless, corticosteroids are well known to increase glucose levels, which may have contributed to our findings. We did not identify a significant association between hyperglycemia and the three outcomes examined, which may be explained by the small sample size and the relatively few glucose measurements taken in the study population. As hyperglycemia was common in this group, special attention should be paid to it to prevent adverse events, especially because other studies with larger series of patients found a significant association between hypergly- cemia and worse outcomes in surgical patients. There were a few limitations associated with this study, particularly due to the retrospective analytical design and consequent lack of a previous protocol of glucose measure- ment. Moreover, some of the surgery subgroups contained few patients, which made it difficult to establish an association between glucose levels and outcomes. The treatment of hyperglycemia in pediatric intensive care must be further analyzed, as there is no consensus on the benefits of several procedures, such as insulin therapy and strict glycemic control in these situations. In children, organic components such as beta cells, liver, kidneys, and muscles have not been exposed to oxidative, lipotoxic or