RESUMO
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.
Assuntos
Edema Encefálico/etiologia , Edema Encefálico/fisiopatologia , Cetoacidose Diabética/complicações , Imageamento por Ressonância Magnética/métodos , Edema Encefálico/metabolismo , Criança , Desidratação , Humanos , Concentração de Íons de Hidrogênio , Hiperventilação , Análise Multivariada , Concentração Osmolar , RespiraçãoRESUMO
OBJECTIVES: Cerebral edema during diabetic ketoacidosis (DKA) has been attributed to osmotic cellular swelling during treatment. We evaluated cerebral water distribution and cerebral perfusion during DKA treatment in children. STUDY DESIGN: We imaged 14 children during DKA treatment and after recovery, using both diffusion and perfusion weighted magnetic resonance imaging (MRI). We assessed the apparent diffusion coefficients (ADCs) and measures reflecting cerebral perfusion. RESULTS: The ADC was significantly elevated during DKA treatment (indicating increased water diffusion) in all regions except the occipital gray matter. Mean reductions in the ADC from initial to postrecovery MRI were: basal ganglia 4.7 +/- 2.5 x 10(-5) mm(2)/s (P=.002), thalamus 3.7 +/- 2.8 x 10(-5) mm(2)/s, (P=.002), periaqueductal gray matter 4.3 +/- 5.1 x 10(-5) mm(2)/s (P=.03), and frontal white matter 2.0 +/- 3.1 x 10(-5) mm(2)/s (P=.03). In contrast, the ADC in the occipital gray matter increased significantly from the initial to postrecovery MRI (mean increase 3.9 +/- 3.9 x 10(-5) mm(2)/s, P=.004). Perfusion MRI during DKA treatment revealed significantly shorter mean transit times (MTTs) and higher peak tracer concentrations, possibly indicating increased cerebral blood flow (CBF). CONCLUSIONS: Elevated ADC values during DKA treatment suggests a vasogenic process as the predominant mechanism of edema formation rather than osmotic cellular swelling.