Risk factors for developing brain herniation during diabetic ketoacidosis

Sodium concentration in rehydration fluids for children with ketoacidotic diabetes: effect on serum sodium concentration

OBJECTIVES

To analyze in a retrospective cohort if sodium concentration in the rehydration fluids influence natremia in children with diabetic ketoacidosis (DKA).

STUDY DESIGN

Consecutive episodes of diabetic ketoacidosis admitted in a tertiary care referral center from 2000 to 2005. Rehydration was programmed for 48 hours with a 2-bag system. Initial rehydration was performed with isotonic fluids and thereafter with variable tonicity. Analysis of the influence of the different factors on natremia was performed with a multivariate linear regression analysis.

RESULTS

Forty-two episodes of DKA were reviewed. Increased sodium content in rehydration fluids behaved as an independent variable, causing a positive tendency of natremia (P < .008).

CONCLUSIONS

Sodium concentration in the rehydration fluids behaves as an independent factor that influences positively the trend of the serum concentration of sodium during DKA rehydration. We propose the use of isotonic solutions for rehydration in diabetic ketoacidosis.

Evaluation of the two-bag system for fluid management in pediatric patients with diabetic ketoacidosis

OBJECTIVES

A one-bag and a two-bag system have both been used to manage intravenous fluid administration in pediatric patients with diabetic ketoacidosis (DKA). The one-bag system, however, has been noted to have limitations, such as slow response time. This study evaluates whether the two-bag system provides any clinical benefit in pediatric DKA patients as compared to the one-bag system.

METHODS

This was a retrospective, non-blinded chart review. Inclusion criteria were patients ≤ 18 years old and whose admission had the code of DKA as the diagnosis. Baseline clinical and demographic data were collected. Descriptive statistics were used in the data analysis.

RESULTS

A total of 31 patients were included, 9 (29%) in the one-bag group and 22 (71%) in the two-bag group. Baseline characteristics were similar between the two groups. Mean (SD) rate of complete blood glucose (CBG) correction was 31.04 mg/dL/hr (20.61) in the two-bag group and 21.04 mg/dL/hr (16.26) in the one-bag group (p = 0.297). The rate of bicarbonate correction, however, was faster with the two-bag system than the one-bag system (0.949 ± 0.553 mEq/L/hr and 0.606 ± 0.297 mEq/L/hr, respectively) (p = 0.047). The two-bag system also had a faster time to ketone (p = 0.04), but not pH (p = 0.172), correction.

CONCLUSIONS

The two-bag system provided a faster rate of bicarbonate and ketone correction compared to the one-bag system. The two-bag system also provided a trend towards a faster rate of blood glucose and pH correction.

Correlation of clinical and biochemical findings with diabetic ketoacidosis-related cerebral edema in children using magnetic resonance diffusion-weighted imaging

OBJECTIVE

To determine clinical and biochemical factors influencing cerebral edema formation during diabetic ketoacidosis (DKA) in children.

STUDY DESIGN

We used magnetic resonance diffusion-weighted imaging to quantify edema formation. We measured the apparent diffusion coefficient (ADC) of brain water during and after DKA treatment in 26 children and correlated ADC changes with clinical and biochemical variables.

RESULTS

Mean ADC values were elevated during DKA treatment compared with baseline (8.13 +/- 0.47 vs 7.74 +/- 0.49 x 10(-4) mm(2)/sec, difference in means 0.40, 95% CI: 0.25 to 0.55, P < .001). Children with altered mental status during DKA had greater elevation in ADC. ADC elevation during DKA was positively correlated with initial serum urea nitrogen concentration (correlation coefficient 0.41, P = .03) and initial respiratory rate (correlation coefficient 0.61, P < .001). ADC elevation was not significantly correlated with initial serum glucose, sodium or effective osmolality, nor with changes in glucose, sodium or osmolality during treatment. Multivariable analyses identified the initial urea nitrogen concentration and respiratory rate as independently associated with ADC elevation.

CONCLUSIONS

The degree of edema formation during DKA in children is correlated with the degree of dehydration and hyperventilation at presentation, but not with factors related to initial osmolality or osmotic changes during treatment. These data support the hypothesis that CE is related to cerebral hypoperfusion during DKA, and that osmotic fluctuations during DKA treatment do not play a primary causal role.

Cerebral blood flow and cerebral edema in rats with diabetic ketoacidosis

OBJECTIVE

Cerebral edema (CE) is a potentially life-threatening complication of diabetic ketoacidosis (DKA) in children. Osmotic fluctuations during DKA treatment have been considered responsible, but recent data instead suggest that cerebral hypoperfusion may be involved and that activation of cerebral ion transporters may occur. Diminished cerebral blood flow (CBF) during DKA, however, has not been previously demonstrated. We investigated CBF and edema formation in a rat model of DKA and determined the effects of bumetanide, an inhibitor of Na-K-Cl cotransport.

RESEARCH DESIGN AND METHODS

Juvenile rats with streptozotocin-induced DKA were treated with intravenous saline and insulin, similar to human treatment protocols. CBF was determined by magnetic resonance (MR) perfusion-weighted imaging before and during treatment, and CE was assessed by determining apparent diffusion coefficients (ADCs) using MR diffusion-weighted imaging.

RESULTS

CBF was significantly reduced in DKA and was responsive to alterations in pCO(2). ADC values were reduced, consistent with cell swelling. The reduction in ADCs correlated with dehydration, as reflected in blood urea nitrogen concentrations. Bumetanide caused a rapid rise in ADCs of DKA rats without significantly changing CBF, while saline/insulin caused a rapid rise in CBF and a gradual rise in ADCs. DKA rats treated with bumetanide plus saline/insulin showed a trend toward more rapid rise in cortical ADCs and a larger rise in striatal CBF than those observed with saline/insulin alone.

CONCLUSIONS

These data demonstrate that CE in DKA is accompanied by cerebral hypoperfusion before treatment and suggest that blocking Na-K-Cl cotransport may reduce cerebral cell swelling.

Cerebral edema in diabetic ketoacidosis

OBJECTIVE

To review the causes of cerebral edema in diabetic ketoacidosis (CEDKA), including pathophysiology, risk factors, and proposed mechanisms, to review the diagnosis, treatment, and prognosis of CEDKA and the treatment of diabetic ketoacidosis as it pertains to prevention of cerebral edema.

DATA SOURCE

A MEDLINE search using OVID was done through 2006 using the search terms cerebral edema and diabetic ketoacidosis. RESULTS OF SEARCH: There were 191 citations identified, of which 150 were used. An additional 42 references listed in publications thus identified were also reviewed, and two book chapters were used.

STUDY SELECTION

The citations were reviewed by the author. All citations identified were used except 25 in foreign languages and 16 that were duplicates or had inappropriate titles and/or subject matter. Of the 194 references, there were 21 preclinical and 40 clinical studies, 35 reviews, 15 editorials, 43 case reports, 29 letters, three abstracts, six commentaries, and two book chapters.

DATA SYNTHESIS

The data are summarized in discussion.

CONCLUSIONS

The causes and mechanisms of CEDKA are unknown. CEDKA may be due as much to individual biological variance as to severity of underlying metabolic derangement of the child's state and/or treatment risk factors. Treatment recommendations for CEDKA and diabetic ketoacidosis are made taking into consideration possible mechanisms and risk factors but are intended as general guidelines only in view of the absence of conclusive evidence.

Diabetic ketoacidosis and cerebral oedema in Sweden--a 2-year paediatric population study

AIM

The aim of this study was to investigate diabetic ketoacidosis (DKA) and cerebral oedema in the Swedish paediatric diabetes population, and to measure laboratory parameters during treatment.

METHODS

The Swedish National Paediatric Diabetes Registry (SWEDIABKIDS) indicates that 16% of patients < 18 years during 2000 to 2004 had DKA at onset of diabetes. Data from 1999 and 2000 was collected retrospectively from all of Sweden by questionnaire.

RESULTS

We identified 292 cases of DKA (pH < 7.30) in 265 children (149 at diabetes onset), aged 0.8-19.9 years. The incidence of DKA in patients with previously diagnosed diabetes was 1.4/100 patient years in 1999 and 1.7/100 in 2000. Two patients, both 11 years old with newly diagnosed diabetes, had overt symptoms of cerebral oedema and one developed neurological sequelae. This corresponds to an incidence of 0.68% (2/292) with no mortality. Symptoms of subclinical cerebral oedema after admission (headache, vomiting, lethargy) were recorded in a further 16 cases. In two of these mannitol was given, and both recovered within 1-2 h. Laboratory data was available from 253/292 episodes. During treatment for DKA, hypokalaemia (< 3.5 mmol/l) was significantly more common at onset of diabetes than in patients with established diabetes (65 vs. 28%, P < 0.001; initial prescription of potassium was 20 mmol/l).

CONCLUSIONS

We conclude that 16% of children with new-onset diabetes presented with DKA at diagnosis and that the incidence of DKA in children with established diabetes was 1.6/100 patient years. Cerebral oedema occurred in 0.68% of the DKA episodes.

An 18-yr prospective study of pediatric diabetic ketoacidosis: an approach to minimizing the risk of brain herniation during treatment

BACKGROUND

During the late 1900s, raised intracranial pressure (ICP) during treatment of pediatric diabetic ketoacidosis (DKA) surfaced as the most important cause of morbidity and mortality in pediatric DKA. The contribution of fluid and electrolyte therapy to neurologic deterioration during treatment remains controversial.

METHODS

We proposed a physiologic approach to treatment of DKA, incorporating the principles of rehydration of hypertonic states. Consecutive episodes of pediatric DKA were managed using continuous intravenous insulin, an individualized assessment of the degree of dehydration, and rehydration solutions of tonicity approximating that of the patient. Gradual replacement of the volume of deficit after correction of shock, if present, was planned over 48 h with special attention to changes in effective osmolality along with intensive cardiorespiratory, neurologic, and biochemical monitoring. Mannitol was given for signs or symptoms of raised ICP.

RESULTS

Six hundred and thirty-five consecutive episodes of pediatric DKA were treated from January 1988 to September 2005. Means +/- standard deviation (SD) for initial measured concentrations of total carbon dioxide, glucose, and urea nitrogen were 7.8 +/- 3.3 mmol/L, 602 +/- 271 mg/dL (33.4 +/- 15 mmol/L), and 21 +/- 1 mg/dL (7.4 +/- 3.6 mmol/L), respectively. Pretreatment blood gases were available for 477 episodes. The mean initial partial pressures of arterial and venous carbon dioxide +/- SD were 16.8 +/- 7 mmHg (kP(a)CO(2)= 2.24 +/- 0.93) for n = 308 and 26.6 +/- 7 mmHg (kP(v)CO(2)= 3.54 +/- 0.93) for n = 169, respectively. Although repair was planned to occur over 48 h, the mean time to achieve clinical rehydration and correction of DKA was 11.6 +/- 6.2 h. Mannitol was given in 35 (5.5%) episodes. There was no neurologic morbidity or mortality.

CONCLUSION

Management of pediatric DKA using this multifaceted physiologic approach and the principles of rehydration described is safe and appears to minimize the risk of brain herniation during treatment.

Preventing a drop in effective plasma osmolality to minimize the likelihood of cerebral edema during treatment of children with diabetic ketoacidosis

OBJECTIVES

To test whether a drop in effective plasma osmolality (P(Eff osm); 2 x plasma sodium [P(Na)] + plasma glucose concentrations) during therapy for diabetic ketoacidosis (DKA) is associated with an increased risk of cerebral edema (CE), and whether the development of hypernatremia to prevent a drop in the P(Eff osm) is dangerous.

STUDY DESIGN

This study is a retrospective comparison of a CE group (n = 12) and non-CE groups with hypernatremia (n = 44) and without hypernatremia (n = 13).

RESULTS

The development of CE (at 6.8 +/- 1.5 hours) was associated with a drop in P(Eff osm) from 304 +/- 5 to 290 +/- 5 mOsm/kg (P < .001). Control patients did not show this drop in P(Eff osm) at 4 hours (1 +/- 2 and 2 +/- 2 vs -9 +/- 2 mOsm/kg; P < .01), because of a larger rise in P(Na) and/or a smaller drop in plasma glucose. During this period, the CE group received more near-isotonic fluids (69 +/- 9 vs 35 +/- 2 and 27 +/- 3 mL/kg; P < .001). The CE group had a higher mortality (3/12 vs 0/57; P = .003), and more neurologic sequelae (5/12 vs 1/57; P < .001).

CONCLUSIONS

CE during therapy for DKA was associated with a drop in P(Eff osm). An adequate rise in P(Na) may be needed to prevent this drop in P(Eff osm).

The UK case-control study of cerebral oedema complicating diabetic ketoacidosis in children

AIMS/HYPOTHESIS

Cerebral oedema complicating diabetic ketoacidosis (DKA) remains the major cause of morbidity and mortality in children with type 1 diabetes, but its aetiology remains unknown. Our objective was to determine the impact of baseline biochemical factors and of treatment-related variables on risk of the development of cerebral oedema in children with DKA.

MATERIALS AND METHODS

This was a national UK case-control study. Through the British Paediatric Surveillance Unit we identified 43 cases of cerebral oedema. Through a parallel reporting system, we also identified 2,940 episodes of DKA and selected 169 control subjects on the basis of comparable age, sex, numbers of new or known cases of diabetes and date of admission. Baseline biochemical data and treatment-related variables were extracted from the clinical notes of cases and control subjects.

RESULTS

Allowing for differences in age, sex and new or known diabetes, cases were more acidotic at diagnosis of DKA (odds ratio [OR] for events in the least acidotic compared with the most acidotic tertile=0.02 [95% CI: 0.002-0.15], p<0.001). In addition, cases had higher potassium and urea levels at baseline. Calculated osmolality and baseline glucose were not significantly different. After allowing for severity of acidosis, insulin administration in the first hour (OR 12.7 [1.41-114.5], p=0.02) and volume of fluid administered over the first 4 h (OR 6.55 [1.38-30.97], p=0.01) were associated with risk. Low baseline plasma sodium and an elevated p(a)CO(2) also contributed to risk in the final regression model. Bicarbonate administration was not associated with increased risk of an event when corrected for acidosis.

CONCLUSIONS/INTERPRETATION

In this case-control study of DKA, baseline acidosis and abnormalities of sodium, potassium and urea concentrations were important predictors of risk of cerebral oedema. Additional risk factors identified were early administration of insulin and high volumes of fluid. These observations should be taken into account when designing treatment protocols.

Frequency of sub-clinical cerebral edema in children with diabetic ketoacidosis

Symptomatic cerebral edema occurs in approximately 1% of children with diabetic ketoacidosis (DKA). However, asymptomatic or subclinical cerebral edema is thought to occur more frequently. Some small studies have found narrowing of the cerebral ventricles indicating cerebral edema in most or all children with DKA, but other studies have not detected narrowing in ventricle size. In this study, we measured the intercaudate width of the frontal horns of the lateral ventricles using magnetic resonance imaging (MRI) in children with DKA during treatment and after recovery from the DKA episode. We determined the frequency of ventricular narrowing and compared clinical and biochemical data for children with and without ventricular narrowing. Forty-one children completed the study protocol. The lateral ventricles were significantly smaller during DKA treatment (mean width, 9.3 +/- 0.3 vs. 10.2 +/- 0.3 mm after recovery from DKA, p < 0.001). Children with ventricular narrowing during DKA treatment (22 children, 54%) were more likely to have mental status abnormalities than those without narrowing [12/22 vs. 4/19 with Glasgow Coma Scale (GCS) scores below 15 during therapy, p = 0.03]. Multiple logistic regression analysis revealed that a lower initial PCO2 level was significantly associated with ventricular narrowing [odds ratio (OR) = 0.88, 95% confidence interval (95% CI) = 0.78-0.99, p = 0.047). No other variables analyzed were associated with ventricular narrowing in the multivariate analysis. We conclude that narrowing of the lateral ventricles is evident in just over half of children being treated for DKA. Although children with ventricular narrowing did not exhibit neurological abnormalities sufficient for a diagnosis of 'symptomatic cerebral edema', mild mental status abnormalities occurred frequently, suggesting that clinical evidence of cerebral edema in children with DKA may be more common than previously reported.

The influence of hyperchloraemia on acid base interpretation in diabetic ketoacidosis

OBJECTIVES

During the acute treatment of diabetic ketoacidosis we (a) determined the temporal incidence of hyperchloraemia, and (b) quantified the influence of hyperchloraemia on interpretation of common blood gas derived acid base parameters, namely base deficit and bicarbonate.

DESIGN AND SETTING

Retrospective chart review in two regional paediatric intensive care units.

MEASUREMENTS AND RESULTS

Stewart's physicochemical theory was used to develop regression equations quantifying the acidifying effect of hyperchloraemia on both base deficit and bicarbonate. These were then applied retrospectively to blood chemistry results from 18 children (median age 12.7 years, weight 43 kg) with diabetic ketoacidosis. Plasma ketonaemia was estimated using the albumin-corrected anion gap. The incidence of hyperchloraemia, as documented by a ratio of plasma chloride to sodium of greater than 0.79, increased from 6% at admission to 94% after 20 h of treatment. Correction for chloride produced a dramatic improvement in the relationship between changes in the anion gap vs. both base deficit (from R(2)=0.55 to R(2)=0.95) and bicarbonate (from R(2)=0.51 to R(2)=0.96) during treatment. After 20 h of treatment the mean base deficit had decreased from 24.7 mmol/l to 10.0 mmol/l however, the proportion that was due to hyperchloraemia increased from 2% to 98%.

CONCLUSIONS

It is now possible using a simple correction factor to quantify the confounding effect of hyperchloraemia on both base deficit and bicarbonate in diabetic ketoacidosis. This bedside tool may be a useful adjunct to guide therapeutic interventions.

Diabetic ketoacidosis in the pediatric ICU

Diabetic ketoacidosis (DKA), a pathophysiologic, life-threatening process that results from uncontrolled diabetes mellitus-induced hyperglycemia, is seen frequently in the pediatric ICU. This article reviews the pathophysiology, management, goals of treatment, and nursing implications of the child who is diagnosed with DKA. Facets particular to the pediatric population are reviewed.

Pediatric diabetic ketoacidosis and hyperglycemic hyperosmolar state

Diabetic ketoacidosis is an important complication of diabetes in children and is the most frequent diabetes-related cause of death in childhood. The pathophysiology of this condition can be viewed as an exaggeration of the normal physiologic mechanisms responsible for maintaining an adequate fuel supply to the brain and other tissues during periods of fasting and physiologic stress. The optimal therapy has been a subject of controversy, particularly because the most frequent serious complication of diabetic ketoacidosis-cerebral edema-and the relationship of this complication to treatment are incompletely understood. In this article, the author reviews the pathophysiology of diabetic ketoacidosis and its complications and presents an evidence-based approach to the management of this condition.

Hyperventilation in severe diabetic ketoacidosis

OBJECTIVE

To explore whether the carbon dioxide-bicarbonate (P(CO(2))-HCO(3)) buffering system in blood and cerebrospinal fluid (CSF) in diabetic ketoacidosis should influence the approach to ventilation in patients at risk of cerebral edema.

DATA SOURCE

Medline search, manual search of references in articles found in Medline search, and use of historical literature from 1933 to 1967.

DESIGN

A clinical vignette is used--a child with severe diabetic ketoacidosis who presented with profound hypocapnia and then deteriorated--as a basis for discussion of integrative metabolic and vascular physiology.

STUDY SELECTION

Studies included reports in diabetic ketoacidosis where arterial and CSF acid-base data have been presented. Studies where simultaneous acid-base, ventilation, respiratory quotient, and cerebral blood flow data are available.

DATA EXTRACTION AND SYNTHESIS

We revisit a hypothesis and, by reassessing data, put forward an argument based on the significance of low [HCO(3)](CSF) and rising Pa(CO(2))- hyperventilation in diabetic ketoacidosis and the limit in biology of survival; repair of severe diabetic ketoacidosis and Pa(CO(2))-and mechanical ventilation.

CONCLUSION

The review highlights a potential problem with mechanical ventilation in severe diabetic ketoacidosis and suggests that the P(CO(2))--HCO(3) hypothesis is consistent with data on cerebral edema in diabetic ketoacidosis. It also indicates that the recommendation to avoid induced hyperventilation early in the course of intensive care may be counter to the logic of adaptive physiology.

Insights into the acute cerebral metabolic changes associated with childhood diabetes

AIMS

Type 1 diabetes is a prevalent chronic disease in childhood with the commonest single cause of death being cerebral oedema in the context of diabetic ketoacidosis (DKA). The nature of the alterations in cerebral metabolism that may result in vulnerability to neuronal injury remains unknown. The aim of this study was to analyse the magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) brain data from eight children with diabetes following acute presentation with hyperglycaemia with or without ketoacidosis, to determine the nature and timing of any alterations in cerebral structure and metabolism.

METHODS

This study used MRI and MRS to investigate regional cerebral abnormalities in a small series of diabetic patients with and without DKA. Changes were compared with the clinical and biochemical features of the patients studied.

RESULTS

Our small series of patients all demonstrated abnormal signal changes in the frontal region on fluid attenuated inversion recovery (FLAIR) MR imaging, suggestive of oedema, and spectroscopic abnormalities of increased taurine, myoinositol and glucose levels. The MR abnormalities varied in severity but did not correlate with any clinical or biochemical parameters.

CONCLUSIONS

These changes indicate that many diabetic children, particularly at presentation, may have alterations in cerebral metabolism with implications for the pathogenesis and treatment of the cerebral complications of DKA. In addition, our findings suggest that increased taurine may be one of the important differentiating factors in the response of the brain of diabetic children to DKA that may reflect an increase in their vulnerability to cerebral oedema compared with diabetic adults.

Population-based study of incidence and risk factors for cerebral edema in pediatric diabetic ketoacidosis

OBJECTIVES

To determine incidence, outcomes, and risk factors for pediatric cerebral edema with diabetic ketoacidosis (CEDKA) in Canada.

STUDY DESIGN

This was a case-control study nested within a population-based active surveillance study of CEDKA in Canada from July 1999 to June 2001. Cases are patients with DKA <16 years of age with cerebral edema. Two unmatched control subjects per case are patients with DKA without cerebral edema.

RESULTS

Thirteen cases of CEDKA were identified over the surveillance period for an incidence rate of 0.51%; 23% died and 15% survived with neurologic sequelae. CEDKA was present at initial presentation of DKA in 19% of cases. CEDKA was associated with lower initial bicarbonate ( P = .001), higher initial urea ( P = .001), and higher glucose at presentation ( P = .014). Although there was a trend to association with higher fluid rates and treatment with bicarbonate, these were not independent predictors.

CONCLUSIONS

CEDKA remains a significant problem with a high mortality rate. No association was found between the occurrence of CEDKA and treatment factors. The presence of cerebral edema before treatment of DKA and the association with severity of illness suggest that prevention of DKA is the key to avoiding this devastating complication.

Hyperemia and impaired cerebral autoregulation in a surgical patient with diabetic ketoacidosis

PURPOSE

We describe cerebral hyperemia and impaired cerebral autoregulation documented with transcranial Doppler (TCD) ultrasonography in an adult patient with diabetic ketoacidosis (DKA) and sepsis presenting for surgery.

CLINICAL FEATURES

Middle cerebral artery flow velocity was increased relative to PaCO(2) (Vmca 52 cm.sec(-1); PaCO(2) 22 mmHg) and the autoregulatory index (ARI) was 0 prior to surgery. Twenty hours after admission and treatment, cerebral hyperemia resolved (Vmca 52 cm.sec(-1) ; PaCO(2) 35 mmHg) and cerebral autoregulation returned to normal (ARI 0.91).

CONCLUSION

To our knowledge, this is the first description of impaired cerebral autoregulation in adult DKA. Our observations suggest a relationship between cerebral hyperemia and impaired cerebral autoregulation in DKA.

Cerebral oedema in childhood diabetic ketoacidosis: is treatment a factor?

Cerebral oedema (CO) is the most dreaded complication of diabetic ketoacidosis (DKA) in children. Despite advances in many areas of the management of DKA, the mortality from CO has remained constant for decades. This rare disorder, complicating about 1% of cases of DKA in children, is lethal in 20% to 50% of victims. Since it was first described in 1936, much effort has gone into the search for a cause for this condition, but CO in childhood DKA remains a mysterious illness. Researchers have suggested that the treatment for DKA may be causally related to the development of CO. Others have disputed this claim, and both camps cite evidence to support their point of view. This article reviews the literature pertinent to the question: Is the treatment of DKA in children responsible for the development of CO?

Bumetanide reduces cerebral edema formation in rats with diabetic ketoacidosis

The mechanisms responsible for cerebral edema formation in diabetic ketoacidosis (DKA) are not well understood, although evidence suggests ischemia as a contributing factor. Previous studies have shown that the Na-K-Cl cotransporter of cerebral microvascular endothelial cells and astrocytes is a major participant in ischemia-induced cerebral edema in stroke. The present study was conducted to test the hypothesis that the Na-K-Cl cotransporter also contributes to cerebral edema in DKA. Sprague-Dawley rats were administered streptozotocin to induce DKA, and then cerebral edema was assessed by determination of apparent diffusion coefficients (ADC) with magnetic resonance diffusion-weighted imaging. Cerebral ADC values in DKA rats were significantly reduced in both cortex and striatum compared with non-DKA control rats, indicating the presence of cerebral edema. Intravenous administration of bumetanide to DKA rats abolished the drop in cortical ADC values, while having no significant effect in the striatum. Insulin and saline treatment had no effect when given after bumetanide but increased both cortical and striatal ADC values when given before bumetanide. Evidence is also presented here that acetoacetate and beta-hydroxybutyrate stimulate brain microvascular Na-K-Cl cotransporter activity. These findings suggest that the Na-K-Cl cotransporter contributes to brain edema in DKA.

Cerebral edema in childhood diabetic ketoacidosis: natural history, radiographic findings, and early identification

OBJECTIVE

Children who develop cerebral edema (CE) during diabetic ketoacidosis (DKA) exhibit definable signs and symptoms of neurological collapse early enough to allow intervention to prevent brain damage. Our objective was to develop a model for early detection of CE in children with DKA.

RESEARCH DESIGN AND METHODS

A training sample of 26 occurrences of DKA complicated by severe CE and 69 episodes of uncomplicated DKA was reviewed. Signs of neurological disease were incorporated into a bedside evaluation protocol that was applied to an independent test sample of 17 patients previously reported to have developed symptomatic CE during treatment for DKA. Head computed tomograms and their reports were reviewed.

RESULTS

The protocol allowed 92% sensitivity and 96% specificity for the recognition of CE sufficiently early for intervention. The diagnostic criteria were fulfilled in two temporal patterns, defining early- and late-onset CE. Although initial computed tomograms were often normal, the findings also included diffuse CE and focal brain injury, the latter only in patients with an early onset of abnormal neurological signs.

CONCLUSIONS

CE may occur in the absence of acute changes on head computed tomograms. Early detection of CE at the bedside using an evidence-based protocol permits intervention in time to prevent permanent brain damage.

ESPE/LWPES consensus statement on diabetic ketoacidosis in children and adolescents

Diabetic ketoacidosis (DKA) is the leading cause of morbidity and mortality in children with type 1 diabetes mellitus (TIDM). Mortality is predominantly related to the occurrence of cerebral oedema; only a minority of deaths in DKA are attributed to other causes. Cerebral oedema occurs in about 0.3-1% of all episodes of DKA, and its aetiology, pathophysiology, and ideal method of treatment are poorly understood. There is debate as to whether physicians treating DKA can prevent or predict the occurrence of cerebral oedema, and the appropriate site(s) for children with DKA to be managed. There is agreement that prevention of DKA and reduction of its incidence should be a goal in managing children with diabetes.

Treatment of extreme hyperglycemia monitored with intracerebral microdialysis

OBJECTIVE

Description of a pediatric patient with hyperosmolar hyperglycemic nonketotic syndrome where the treatment was monitored with intracerebral microdialysis.

DESIGN

Case report.

SETTING

Intensive care unit at a university hospital.

PATIENT

An 11-yr-old boy with new-onset diabetes who presented with a blood glucose concentration of 100 mmol/L (1800 mg/dL) and a serum osmolality of 448 mOsm/kg.

INTERVENTIONS

Interventions included intracerebral and subcutaneous microdialysis as well as intracranial pressure monitoring during correction of the hyperosmolar condition. The strategy was to decrease osmolality by 1 mOsm.kg(-1).hr(-1) and blood glucose by 1.5 mmol.L(-1).hr(-1) (27 mg/dL).

MEASUREMENTS AND MAIN RESULTS

The concentrations of glucose in the subcutaneous dialysates corresponded to the blood glucose concentrations. The brain/subcutaneous glucose ratio varied between 0.20 and 1.28 (mean, 0.43; median, 0.4). When the blood glucose decreased quickly after steady state, the brain/subcutaneous ratio increased sharply, demonstrating that the normalization of glucose in the brain was slower than that in blood.

CONCLUSIONS

Microdialysis can be used to monitor the brain/subcutaneous glucose ratio in patients with extreme hyperglycemia. A rapid decrease in blood glucose increases the brain/subcutaneous glucose ratio, which may be a potential risk factor for osmotic brain edema. Microdialysis may prove to be a valuable tool in treatment management. The child made a full recovery.

Critical issues in endocrinology

Endocrine emergencies are commonly encountered in the ICU. This article focuses on several important endocrine emergencies, including diabetic hyperglycemic states, adrenal insufficiency, myxedema coma, thyroid storm, and pituitary apoplexy. Other endocrine issues that are related to intensive care, such as intensive insulin therapy, relative adrenal insufficiency, and thyroid function test abnormalities are also covered in detail.

Factors associated with adverse outcomes in children with diabetic ketoacidosis-related cerebral edema

OBJECTIVE

To investigate the relation between outcomes of children with diabetic ketoacidosis (DKA)-related cerebral edema and baseline clinical features and therapeutic interventions for treatment of cerebral edema.

STUDY DESIGN

All children </=18 years old with DKA and cerebral edema (n = 61) were retrospectively identified from 10 pediatric centers between 1982 and 1997. Demographic, biochemical, and therapeutic data were collected. Ordinal logistic regression analysis was used to identify factors associated with the clinical outcome (death or persistent vegetative state; mild to moderate neurological disability; or normal) after adjusting for known risk factors for the development of cerebral edema as well as the degree of neurologic depression at the time of diagnosis of cerebral edema.

RESULTS

Seventeen (28%) children died or survived in a vegetative state; 8 (13%) survived with mild to moderate neurologic disabilities; and 36 (59%) survived without sequelae. Factors associated with poor outcomes included greater neurologic depression at the time of diagnosis of cerebral edema, a high initial serum urea nitrogen concentration, and intubation with hyperventilation to a PCO (2) <22 mm Hg.

CONCLUSIONS

After adjusting for potential confounding variables and the degree of neurologic compromise at the initiation of therapy, intubation with hyperventilation is associated with adverse outcomes of DKA-related cerebral edema. Greater neurologic depression at the time of diagnosis of cerebral edema and a higher initial serum urea nitrogen concentration are also associated with poor outcome.

Diabetic ketoacidosis and cerebral edema

Cerebral edema is the leading cause of death in children presenting in diabetic ketoacidosis and occurs in 0.2 to 1% of cases. The osmolar gradient caused by the high blood glucose results in water shift from the intracelluar fluid (ICF) to the extracellular fluid (ECF) space and contraction of cell volume. Correction with insulin and intravenous fluids can result in a rapid reduction in effective osmolarity, reversal of the fluid shift and the development of cerebral edema. The goals for treatment should be a combination of intravenous fluid and insulin that results in a gradual reduction of the effective osmolarity over a 36- to 48-hour period, thereby avoiding rapid expansion of the ICF compartment and brain swelling.

Trends in diabetic ketoacidosis in childhood and adolescence: a 15-yr experience

The number of episodes of diabetic ketoacidosis (DKA) is a significant outcome measure for diabetes care. We ascertained patterns of admission due to DKA over 15 yr to determine whether this indicator of diabetes care had improved in parallel with clinical practices. Between 1 January 1985 and 31 December 1999, 630 admissions were reviewed. We subanalyzed these admissions according to whether the patient was newly diagnosed, had infrequent episodes of DKA (non-relapsers) or had frequent (> or = 2/yr) episodes of DKA (relapsers). Overall there was a slight downward trend in the incidence of DKA admissions over the study period. There was a proportionate increase in the incidence of DKA amongst newly diagnosed patients, with a proportionate decrease in the incidence of DKA seen in relapsers. DKA occurring in non-relapsers remained relatively stable. Adverse clinical events during the admission were relatively uncommon and occurred in all three subgroups. There was no significant difference in HbA1C prior to admission between the relapser and non-relapser groups and there was similarity in the degree of acidosis between all three subgroups. The frequency of significant complications associated with DKA remained unchanged over the study period. Slower rehydration policies were not associated with decreases in either cerebral edema or death rates. DKA remains a significant complication of type 1 diabetes associated with a variety of significant adverse events. Our experience indicates that further efforts to reduce the occurrence of DKA must be focused upon earlier diagnosis and intervention in newly diagnosed patients.

Prehospital cardiac arrest in diabetic ketoacidemia: why brain swelling may lead to death before treatment

An adolescent is reported with type 1 diabetes mellitus and diabetic ketoacidemia (DKA) who died from brain herniation prior to treatment with intravenous fluids and intravenous insulin. The pathophysiology of raised intracranial pressure (ICP) and water intoxication is discussed. As DKA evolves, water and electrolyte losses are replaced by very hypotonic fluids taken orally, leading to a physiologic excess of free water that would cause brain swelling prior to treatment. Central nervous system acidosis may interfere with normal compensatory mechanisms that help prevent small increases in ICP. The pathophysiology of pre-treatment brain swelling has important implications for rehydration with intravenous fluids and treatment with insulin. Prevention of DKA is paramount as well as complete postmortem evaluation of patients who die from this disease.

Diabetic ketoacidosis in the pediatric patient

Diabetic ketoacidosis is the major source of morbidity and mortality in patients with Type I diabetes mellitus. One population-based study noted that approximately 25% of newly diagnosed patients present with diabetic ketoacidosis. Most of those hospitalized with diabetes ketoacidosis, however, are those with poor control of their pre-existing diabetes. Cerebral edema has been found to be present in only 1% of children with diabetic ketoacidosis, but accounts for 20% of all diabetes-related deaths. Although the mortality rate has fallen dramatically over the course of the last century, the underlying mechanisms involved with the development of cerebral edema are still not clear. Several studies have shown specific risk factors to be associated with cerebral edema, but as of yet no reduction in the recent incidence of cerebral edema has been demonstrated. A discussion of these risk factors and a suggested protocol for treating diabetic ketoacidosis are included in this review.

Improving management of diabetic ketoacidosis in children

OBJECTIVE

The optimal fluid management for diabetic ketoacidosis (DKA) is uncertain. In an effort to simplify DKA therapy, we revised the treatment protocol in our institution to use a simpler method of calculating fluid needs, use fluids with higher sodium concentration, and allow glucose concentration to be adjusted easily. We performed a retrospective study to determine the effects of these revisions.

DESIGN

We compared patients treated with traditional and revised protocols (~220 and ~300 patients, respectively, over consecutive 2.75-year intervals). Sixty patient records were randomly selected from the first group (30 treated with each of 2 protocol versions) and 30 from the second group. Biochemical and clinical parameters were analyzed.

RESULTS

Patients selected for detailed analysis were similar in demographics and initial laboratory measurements. Patients treated under the revised fluid protocol received less total fluid, needed fewer intravenous fluid changes, were treated at less cost, and resolved acidosis more rapidly than patients treated under the original protocols. The rate of cerebral edema (0.3%-0.5%) was unchanged.

CONCLUSION

A DKA protocol that necessitates less fluid delivery and fewer calculations simplifies therapy and is associated with more rapid correction of acidosis.

Diabetic ketoacidosis with intracerebral complications

PURPOSE

To describe 11 instances of severe diabetic ketoacidosis (DKA) with secondary intracerebral complications (ICCs), nine of whom were treated early and showed complete recovery.

METHODS

Three hundred and eighty-one episodes of DKA were treated at Denver Children's Hospital (DCH) from January 1989 to December 1999. Nine instances of DKA with ICC were prospectively identified during this time period. Two additional occurrences were identified via a medical records search (total incidence, 2.9%). The signs, symptoms and laboratory values which led to their diagnosis and treatment are identified.

RESULTS

All nine children who received early treatment with i.v. mannitol showed complete recovery. An additional patient had central nervous system involvement upon arrival at our hospital and showed almost complete recovery. Another patient suffered a cardiorespiratory arrest before transfer to our hospital and died without being treated for cerebral edema.

CONCLUSION

Prevention of ICCs by the earlier diagnosis of diabetes and by being aware of possible risk factors for cerebral edema is the eventual goal. Based on our experience, mannitol should be given promptly for the treatment of ICCs indicated by the clinical course even if cerebral edema is not documented by a computed tomography (CT) scan.

Cerebral edema in children with diabetic ketoacidosis

Cerebral edema is the most frequent serious complication of diabetic ketoacidosis (DKA) in children, occurring in 1% to 5% of DKA episodes. The rates of mortality and permanent neurologic morbidity from this complication are high. The pathophysiologic mechanisms underlying DKA-related cerebral edema are unclear. A number of past and more recent studies have investigated biochemical and therapeutic risk factors for the development of cerebral edema. Recent studies have shown that a higher initial serum urea nitrogen concentration and lower initial partial pressure of carbon dioxide are associated with the development of cerebral edema. This and other information suggests that the pathophysiology of DKA-related cerebral edema may involve cerebral ischemia.

Risk factors for cerebral edema in children with diabetic ketoacidosis. The Pediatric Emergency Medicine Collaborative Research Committee of the American Academy of Pediatrics

BACKGROUND

Cerebral edema is an uncommon but devastating complication of diabetic ketoacidosis in children. Risk factors for this complication have not been clearly defined.

METHODS

In this multicenter study, we identified 61 children who had been hospitalized for diabetic ketoacidosis within a 15-year period and in whom cerebral edema had developed. Two additional groups of children with diabetic ketoacidosis but without cerebral edema were also identified: 181 randomly selected children and 174 children matched to those in the cerebral-edema group with respect to age at presentation, onset of diabetes (established vs. newly diagnosed disease), initial serum glucose concentration, and initial venous pH. Using logistic regression we compared the three groups with respect to demographic characteristics and biochemical variables at presentation and compared the matched groups with respect to therapeutic interventions and changes in biochemical values during treatment.

RESULTS

A comparison of the children in the cerebral-edema group with those in the random control group showed that cerebral edema was significantly associated with lower initial partial pressures of arterial carbon dioxide (relative risk of cerebral edema for each decrease of 7.8 mm Hg [representing 1 SD], 3.4; 95 percent confidence interval, 1.9 to 6.3; P<0.001) and higher initial serum urea nitrogen concentrations (relative risk of cerebral edema for each increase of 9 mg per deciliter [3.2 mmol per liter] [representing 1 SD], 1.7; 95 percent confidence interval, 1.2 to 2.5; P=0.003). A comparison of the children with cerebral edema with those in the matched control group also showed that cerebral edema was associated with lower partial pressures of arterial carbon dioxide and higher serum urea nitrogen concentrations. Of the therapeutic variables, only treatment with bicarbonate was associated with cerebral edema, after adjustment for other covariates (relative risk, 4.2; 95 percent confidence interval, 1.5 to 12.1; P=0.008).

CONCLUSIONS

Children with diabetic ketoacidosis who have low partial pressures of arterial carbon dioxide and high serum urea nitrogen concentrations at presentation and who are treated with bicarbonate are at increased risk for cerebral edema.

Problems associated with intravenous fluid administration in children: do we have the right solutions?

Edema, both in its cellular and tissue form, is a frequent complication in critically ill patients. In health, a balance is struck between intracellular and extracellular osmotic forces and interstitial and intravascular oncotic forces, which in turn governs fluid distribution between the intracellular, extracellular and interstitial fluid compartments. The use of hypo- and hypernotic electrolyte solutions has major effects on brain cells, which can be detrimental or beneficial. The controversy over the use of colloids versus crystalloid solutions in critically ill patients remains unresolved.