Cerebral hyperemia measured with near infrared spectroscopy during treatment of diabetic ketoacidosis in children

Cerebral edema associated with diabetic ketoacidosis: Two case reports

Background

Diabetic ketoacidosis (DKA) is associated with a high mortality rate, especially if cerebral edema develops during the disease course. It is rarer and more severe in adults than in children. We present cases of two patients with cerebral edema-related DKA.

Case presentation

The first patient was a 38-year-old man with diabetes mellitus who presented with DKA-related disturbed consciousness. Although glycemic correction was performed slowly, he showed pupil dilation 11 h later. He underwent emergency ventricular drainage, but died of cerebral herniation. The second patient was a 25-year-old woman who presented with impaired consciousness secondary to DKA. Head computed tomography showed subarachnoid hemorrhage and cerebral edema. No related intraoperative findings were observed; it was concluded that the first computed tomography scan revealed pseudo-subarachnoid hemorrhage.

Conclusion

Diabetic ketoacidosis-related cerebral edema develops despite treatment according to guidelines and is difficult to predict. Therefore, adult patients should be treated cautiously during DKA management.

Multimodal Neurologic Monitoring in Children With Acute Brain Injury

Children with acute neurologic illness are at high risk of mortality and long-term neurologic disability. Severe traumatic brain injury, cardiac arrest, stroke, and central nervous system infection are often complicated by cerebral hypoxia, hypoperfusion, and edema, leading to secondary neurologic injury and worse outcome. Owing to the paucity of targeted neuroprotective therapies for these conditions, management emphasizes close physiologic monitoring and supportive care. In this review, we will discuss advanced neurologic monitoring strategies in pediatric acute neurologic illness, emphasizing the physiologic concepts underlying each tool. We will also highlight recent innovations including novel monitoring modalities, and the application of neurologic monitoring in critically ill patients at risk of developing neurologic sequelae.

Bihemispheric Cerebral Oximetry Monitoring's Functionality in Suspected Cerebral Edema Diabetic Ketoacidosis With Therapeutic 3% Hyperosmolar Therapy in a Pediatric Emergency Department

BACKGROUND

Suspected cerebral edema diabetic ketoacidosis (SCEDKA) is more common than perceived with symptoms including altered mentation, headache with vomiting, depressed Glasgow coma scale (GCS), abnormal motor or verbal responses, combativeness, and neurological depression. Suspected cerebral edema diabetic ketoacidosis has been associated with initial diabetic ketoacidosis (DKA) presentation and at start of DKA therapy.Cerebral oximetry (bihemispheric regional cerebral oxygen saturation [rcSO2] and cerebral blood volume index [CBVI]) can detect increased intracranial pressure (ICP)-induced altered bihemispheric cerebral physiology (rcSO2) (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700). In pediatrics, rcSO2 of less than 60% or rcSO2 of greater than 85% reflects increased ICP and cerebral edema (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700). Cerebral oximetry can detect increased ICP-induced altered bihemispheric cerebral physiology (rcSO2, CBVI) and cerebral physiological changes (rcSO2, CBVI changes) during therapeutic mechanical cerebral spinal fluid removal to decrease increased ICP (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700).In the pediatric intensive care units, SCEDKA patients with nonbihemispheric cerebral oximetry showed an initial rcSO2 of greater than 90%. Bihemispheric rcSO2 with CBVI in SCEDKA patients has the potential to detect the abnormal cerebral physiology and disruptive autoregulation while detecting 3% hypertonic saline solution (HTS) effects on the SCEDKA altered cerebral physiology (rcSO2).

PURPOSE

The purposes of this study were to analyze and compare 3% HTS effect on bihemispheric rcSO2 readings, neurological and biochemical parameters in SCEDKA with 3% HTS infusion to non-SCEDKA patients in pediatric emergency department (PED).

METHODS

An observational retrospective comparative analysis study of bihemispheric rcSO2 readings, neurological and biochemical parameters in 2 groups of PED DKA patients were performed: PED DKA patients with SCEDKA +3% HTS infusions versus non-SCEDKA without 3% HTS infusions.

RESULTS

From 2008 to 2013, of the 1899 PED DKA patients, 60 SCEDKA patients received 3% HTS (5 mL/kg via peripheral intravenous) infusion (median age of 5 years [range, 3.7-7 years]), with 42 new DKA insulin dependent diabetes mellitus onset. Suspected cerebral edema diabetic ketoacidosis patients had GCS of 11 (range, 11-12), with consistent SCEDKA signs and symptoms (severe headaches with vomiting, confusion, blurred vision, altered speech, lethargy, and combativeness). Suspected cerebral edema diabetic ketoacidosis patients' initial (0-5 minutes) left rcSO2 readings were 91.4% (range, 88.4%-94.1%) and right was 90.3% (range, 88.6%-94.1%) compared with non-SCEDKA patients' left rcSO2 readings of 73.2% (range, 69.7%-77.8%) and right of 73.2% (range, 67.6%-77%) (P < 0.0001). The rcSO2 monitoring time before 3% HTS infusion was 54.9 minutes (range, 48.3-66.8 minutes) with 3% HTS time effect change: pre-3% HTS (54.9 minutes [range, 48.3-66.8 minutes]). Before 3% HTS infusion, the left rcSO2 readings were 90.0% (range, 89%-95%) and right was 91% (range, 86%-95%). The 30 to 45 minutes post-3% HTS showed that left was 64% (range, 62%-69%) and right was 65.4% (range, 63%-70%) (P < 0.0001). rcSO2 Δ change for post-3% HTS (0-20 minutes) to pre-3% HTS was as follows: left, -26.58 (-29.5 to -23.7) (P < 0.0001); right, -25.2 (-27.7 to -22.6) (P < 0.0001). Post-3% HTS GCS (14,15) and biochemistry compared with pre-3% HTS infusions all improved (P < 0.001).

CONCLUSIONS

In PED SCEDKA patients, the pre-3% HTS bihemispheric rcSO2 readings were greater than 90% and had lower GCS than non-SCEDKA patients. The post-3% HTS infusion rcSO2 readings showed within minutes a substantial reduction compared with non-SCEDKA patients, with no complications. Changes in rcSO2 readings after 3% HTS correlated with improved SCEDKA indicators (improved mental status, headache, and GCS) without any complications. We showed that cerebral oximetry in PED SCEDKA patients has shown an initial bihemispheric of greater than 90% readings signifying abnormal bihemispheric cerebral physiology. We also showed the cerebral oximetry's functionality in detecting 3% HTS therapeutic effects on SCEDKA's abnormal cerebral physiology and the beneficial therapeutic effects of 3% HTS infusion in SCEDKA patients. Using cerebral oximetry in pediatric DKA patients' initial cerebral assessment could have a significant impact in detecting SCEDKA patients. Further SCEDKA research using cerebral oximetry should be considered.

Brain injury in children with diabetic ketoacidosis: Review of the literature and a proposed pathophysiologic pathway for the development of cerebral edema

Cerebral edema (CE) is a potentially devastating complication of diabetic ketoacidosis (DKA) that almost exclusively occurs in children. Since its first description in 1936, numerous risk factors have been identified; however, there continues to be uncertainty concerning the mechanisms that lead to its development. Currently, the most widely accepted hypothesis posits that CE occurs as a result of ischemia-reperfusion injury, with inflammation and impaired cerebrovascular autoregulation contributing to its pathogenesis. The role of specific aspects of DKA treatment in the development of CE continues to be controversial. This review critically examines the literature on the pathophysiology of CE and attempts to categorize the findings by types of brain injury that contribute to its development: cytotoxic, vasogenic, and osmotic. Utilizing this scheme, we propose a multifactorial pathway for the development of CE in patients with DKA.

Management of Diabetic Ketoacidosis in Children and Adolescents with Type 1 Diabetes Mellitus

Diabetic ketoacidosis (DKA) is the end result of insulin deficiency in type 1 diabetes mellitus (T1D). Loss of insulin production leads to profound catabolism with increased gluconeogenesis, glycogenolysis, lipolysis, and muscle proteolysis causing hyperglycemia and osmotic diuresis. High levels of counter-regulatory hormones lead to enhanced ketogenesis and the release of 'ketone bodies' into the circulation, which dissociate to release hydrogen ions and cause an overwhelming acidosis. Dehydration, hyperglycemia, and ketoacidosis are the hallmarks of this condition. Treatment is effective repletion of insulin, fluids and electrolytes. Newer approaches to early diagnosis, treatment, and prevention may diminish the risk of DKA and its childhood complications including cerebral edema. However, the potential for some technical and pharmacologic advances in the management of T1D to increase DKA events must be recognized.

Hypertension during Diabetic Ketoacidosis in Children

OBJECTIVES

To characterize hemodynamic alterations occurring during diabetic ketoacidosis (DKA) in a large cohort of children and to identify clinical and biochemical factors associated with hypertension.

STUDY DESIGN

This was a planned secondary analysis of data from the Pediatric Emergency Care Applied Research Network Fluid Therapies Under Investigation in DKA Study, a randomized clinical trial of fluid resuscitation protocols for children in DKA. Hemodynamic data (heart rate, blood pressure) from children with DKA were assessed in comparison with normal values for age and sex. Multivariable statistical modeling was used to explore clinical and laboratory predictors of hypertension.

RESULTS

Among 1258 DKA episodes, hypertension was documented at presentation in 154 (12.2%) and developed during DKA treatment in an additional 196 (15.6%), resulting in a total of 350 DKA episodes (27.8%) in which hypertension occurred at some time. Factors associated with hypertension at presentation included more severe acidosis, (lower pH and lower pCO₂), and stage 2 or 3 acute kidney injury. More severe acidosis and lower Glasgow Coma Scale scores were associated with hypertension occurring at any time during DKA treatment.

CONCLUSIONS

Despite dehydration, hypertension occurs in a substantial number of children with DKA. Factors associated with hypertension include greater severity of acidosis, lower pCO_2, and lower Glasgow Coma Scale scores during DKA treatment, suggesting that hypertension might be centrally mediated.

Fluid treatment for children with diabetic ketoacidosis: How do the results of the pediatric emergency care applied research network Fluid Therapies Under Investigation in Diabetic Ketoacidosis (FLUID) Trial change our perspective?

The optimal fluid treatment protocol for children with diabetic ketoacidosis (DKA) has long been a subject of controversy. Until recently, there was no high-quality evidence from randomized clinical trials to support an optimal guideline, and recommendations were mainly based on theoretical considerations. As a consequence, fluid treatment protocols for children with DKA vary between institutions (and countries). In June 2018, the results from the Fluid Therapies Under Investigation in DKA Trial conducted in the Pediatric Emergency Care Applied Research Network were published. This large, factorial-designed randomized controlled trial assessed neurological outcomes of 1387 children with DKA who were treated with one of four fluid protocols that varied in infusion rate and sodium content. In this commentary, we review and discuss the results of this new study and the implications for clinical care of DKA in children.

Clinical Trial of Fluid Infusion Rates for Pediatric Diabetic Ketoacidosis

BACKGROUND

Diabetic ketoacidosis in children may cause brain injuries ranging from mild to severe. Whether intravenous fluids contribute to these injuries has been debated for decades.

METHODS

We conducted a 13-center, randomized, controlled trial that examined the effects of the rate of administration and the sodium chloride content of intravenous fluids on neurologic outcomes in children with diabetic ketoacidosis. Children were randomly assigned to one of four treatment groups in a 2-by-2 factorial design (0.9% or 0.45% sodium chloride content and rapid or slow rate of administration). The primary outcome was a decline in mental status (two consecutive Glasgow Coma Scale scores of <14, on a scale ranging from 3 to 15, with lower scores indicating worse mental status) during treatment for diabetic ketoacidosis. Secondary outcomes included clinically apparent brain injury during treatment for diabetic ketoacidosis, short-term memory during treatment for diabetic ketoacidosis, and memory and IQ 2 to 6 months after recovery from diabetic ketoacidosis.

RESULTS

A total of 1389 episodes of diabetic ketoacidosis were reported in 1255 children. The Glasgow Coma Scale score declined to less than 14 in 48 episodes (3.5%), and clinically apparent brain injury occurred in 12 episodes (0.9%). No significant differences among the treatment groups were observed with respect to the percentage of episodes in which the Glasgow Coma Scale score declined to below 14, the magnitude of decline in the Glasgow Coma Scale score, or the duration of time in which the Glasgow Coma Scale score was less than 14; with respect to the results of the tests of short-term memory; or with respect to the incidence of clinically apparent brain injury during treatment for diabetic ketoacidosis. Memory and IQ scores obtained after the children's recovery from diabetic ketoacidosis also did not differ significantly among the groups. Serious adverse events other than altered mental status were rare and occurred with similar frequency in all treatment groups.

CONCLUSIONS

Neither the rate of administration nor the sodium chloride content of intravenous fluids significantly influenced neurologic outcomes in children with diabetic ketoacidosis. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the Health Resources and Services Administration; PECARN DKA FLUID ClinicalTrials.gov number, NCT00629707 .).

Treatment with the KCa3.1 inhibitor TRAM-34 during diabetic ketoacidosis reduces inflammatory changes in the brain

BACKGROUND

Diabetic ketoacidosis (DKA) causes brain injuries in children ranging from subtle to life-threatening. Previous studies suggest that DKA-related brain injury may involve both stimulation of Na-K-Cl cotransport and microglial activation. Other studies implicate the Na-K-Cl cotransporter and the Ca-activated K channel KCa3.1 in activation of microglia and ischemia-induced brain edema. In this study, we determined whether inhibiting cerebral Na-K-Cl cotransport or KCa3.1 could reduce microglial activation and decrease DKA-related inflammatory changes in the brain.

METHODS

Using immunohistochemistry, we investigated cellular alterations in brain specimens from juvenile rats with DKA before, during and after insulin and saline treatment. We compared findings in rats treated with and without bumetanide (an inhibitor of Na-K-Cl cotransport) or the KCa3.1 inhibitor TRAM-34.

RESULTS

Glial fibrillary acidic protein (GFAP) staining intensity was increased in the hippocampus during DKA, suggesting reactive astrogliosis. OX42 staining intensity was increased during DKA in the hippocampus, cortex and striatum, indicating microglial activation. Treatment with TRAM-34 decreased both OX42 and GFAP intensity suggesting a decreased inflammatory response to DKA. Treatment with bumetanide did not significantly alter OX42 or GFAP intensity.

CONCLUSIONS

Inhibiting KCa3.1 activity with TRAM-34 during DKA treatment decreases microglial activation and reduces reactive astrogliosis, suggesting a decreased inflammatory response.

MEK/ERK- and calcineurin/NFAT-mediated mechanism of cerebral hyperemia and brain injury following NMDA receptor activation

N-methyl-d-aspartate (NMDA) receptor activation increases regional cerebral blood flow (rCBF) and induces neuronal injury, but similarities between these processes are poorly understood. In this study, by measuring rCBF in vivo, we identified a clear correlation between cerebral hyperemia and brain injury. NMDA receptor activation induced brain injury as a result of rCBF increase, which was attenuated by an inhibitor of mitogen-activated protein kinase or calcineurin. Moreover, NMDA induced phosphorylation of extracellular signal-regulated kinase (ERK) and nuclear translocation of nuclear factor of activated T-cell (NFAT) in neurons. Therefore, a MEK/ERK- and calcineurin/NFAT-mediated mechanism of neurovascular coupling underlies the pathophysiology of neurovascular disorders.

Regional Brain Water Content and Distribution During Diabetic Ketoacidosis

OBJECTIVE

To characterize regional differences in brain water distribution and content during diabetic ketoacidosis (DKA) in children and determine whether these differences correlate with regional vascular supply.

STUDY DESIGN

We compared changes in brain water distribution and water content in different brain regions during DKA by analyzing magnetic resonance diffusion weighted imaging data collected during DKA and after recovery in 45 children (<18 years of age). We measured the apparent diffusion coefficient (ADC) of water in the frontal and occipital cortex, basal ganglia, thalamus, hippocampus, and medulla. Brain water content was also measured in a subset of patients.

RESULTS

ADC values were elevated (suggesting vasogenic cerebral edema) in the frontal cortex, basal ganglia, thalamus, and hippocampus during DKA. In contrast, ADC values in the medulla and the occipital cortex were not increased during DKA, and ADC changes in the medulla tended to be negatively correlated with other regions. Regions supplied by the anterior/middle cerebral artery circulation had greater elevations in both ADC and brain water content during DKA compared with regions supplied by the posterior cerebral artery circulation.

CONCLUSIONS

ADC changes during DKA in the brainstem contrast with those of other brain regions, and changes in both ADC and brain water content during DKA vary according to regional vascular supply. These data suggest that brainstem blood flow might possibly be reduced during DKA concurrent with hyperemia in other brain regions.

Serial optic nerve sheath diameter ultrasonography during pediatric diabetic ketoacidosis management: A pilot study

OBJECTIVE

Intracranial hypertension is an infrequent but serious acute complication of pediatric diabetic ketoacidosis (DKA). Subclinical elevations of intracranial pressures however, may be more common, and can be indirectly evaluated with ultrasonography of the optic nerve sheath diameter (ONSD). In this pilot study, we report serial data on ONSD trajectories from five pediatric patients with DKA to generate hypotheses for future studies.

METHODS

Five pediatric patients with type 1 diabetes presented to our emergency department with DKA and enrolled in our study <3h after initiation of treatment. Ultrasonographic evaluation of the ONSD was conducted at presentation, every three hours until resolution of acidosis, and finally 24h post presentation. Following each interval evaluation, a clinical bedside neurologic tool developed for detecting cerebral edema in DKA was utilized.

RESULTS

Four of the five patients exhibited a similar "bell" shaped trajectory - an increase of ONSD after initiation of treatment followed by a return to admission baseline. Patients demonstrated peak ONSDs nine and twelve hours after DKA therapy was initiated, at resolution of acidosis, and at admission. No children exhibited clinical signs suggestive of cerebral edema.

CONCLUSIONS

Peak ONSDs cannot be reliability determined in children with DKA unless serial investigations are conducted. Practices to mitigate risks for intracranial hypertension may require constant surveillance during DKA management.

Brain cell swelling during hypocapnia increases with hyperglycemia or ketosis

BACKGROUND

Severe hypocapnia reduces cerebral blood flow (CBF) and is known to be a risk factor for diabetic ketoacidosis (DKA)-related cerebral edema and cerebral injury in children. Reductions in CBF resulting from hypocapnia alone, however, would not be expected to cause substantial cerebral injury. We hypothesized that either hyperglycemia or ketosis might alter the effects of hypocapnia on CBF and/or cerebral edema associated with CBF reduction.

METHODS

We induced hypocapnia (pCO₂ 20 ± 3 mmHg) via mechanical ventilation in three groups of juvenile rats: 25 controls, 22 hyperglycemic rats (serum glucose 451 ± 78 mg/dL), and 15 ketotic rats (β-hydroxy butyrate 3.0 ± 1.0 mmol/L). We used magnetic resonance imaging to measure CBF and apparent diffusion coefficient (ADC) values in these groups and in 17 ventilated rats with normal pCO₂ (40 ± 3 mmHg). In a subset (n = 35), after 2 h of hypocapnia, pCO₂ levels were normalized (40 ± 3 mmHg) and ADC and CBF measurements were repeated.

RESULTS

Declines in CBF with hypocapnia occurred in all groups. Normalization of pCO₂ after hypocapnia resulted in hyperemia in the striatum. These effects were not substantially altered by hyperglycemia or ketosis. Declines in ADC (suggesting brain cell swelling) during hypocapnia, however, were greater during both hyperglycemia and ketosis.

CONCLUSIONS

We conclude that brain cell swelling associated with hypocapnia is increased by both hyperglycemia and ketosis, suggesting that these metabolic conditions may make the brain more vulnerable to injury during hypocapnia.

Transcranial Doppler-based assessment of cerebral autoregulation in critically ill children during diabetic ketoacidosis treatment

OBJECTIVES

Impaired cerebral autoregulation may be associated with poor outcome in diabetic ketoacidosis. We examined change in cerebral autoregulation during diabetic ketoacidosis treatment.

DESIGN

Prospective observational cohort study.

SETTING

Tertiary care children's hospital.

PATIENTS/SUBJECTS

Children admitted to the ICU with diabetic ketoacidosis (venous pH < 7.3, glucose > 300 mg/dL, HCO3 < 15 mEq/L, and ketonuria) constituted cases, and children with type I diabetes without diabetic ketoacidosis constituted controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Between 2005 and 2009, 32 cases and 50 controls were enrolled. Transcranial Doppler ultrasonography was used to measure middle cerebral artery flow velocities, and cerebral autoregulation testing was achieved via tilt-table testing. Cases underwent two and controls underwent one cerebral autoregulation test. Cerebral autoregulation was quantified by the autoregulatory index (autoregulatory index < 0.4 = impaired and autoregulatory index 0.4-1.0 = intact autoregulation). The first autoregulation test was obtained early (time 1, 12-24 hr; median [interquartile range], 8 hr [5-18 hr]) during diabetic ketoacidosis treatment, and a second autoregulation test was obtained during recovery (time 2, 36-72 hr; median [ interquartile range], 46 hr [40-59 hr]) from time 0 (defined as time of insulin start). Cases had lower autoregulatory index at time 1 than time 2 (p < 0.001) as well lower autoregulatory index than control subjects (p < 0.001). Cerebral autoregulation was impaired in 40% (n = 13) of cases at time 1 and in 6% (n = 2) of cases at time 2. Five cases (17%) showed persistent impairment of cerebral autoregulation between times 1 and 2 of treatment. All control subjects had intact cerebral autoregulation.

CONCLUSIONS

Impaired cerebral autoregulation was common early during diabetic ketoacidosis treatment. Although the majority improved during diabetic ketoacidosis treatment, 17% of subjects had impairment between 36 and 72 hours after start of insulin therapy. The observed impaired cerebral autoregulation appears specific to the diabetic ketoacidosis process in patients with type I diabetes.