First Evidence-Based Approach Allows Early

First Evidence-Based Approach Allows Early Diagnosis of Cerebral Edema in DKA
Investigators propose the first evidence-based approach to diagnosing cerebral edema (CE) in children with diabetic ketoacidosis (DKA) early enough to intervene. “Children who develop CE during DKA exhibit definable signs and symptoms of neurological collapse early enough to allow intervention to prevent brain damage,” write Andrew B. Muir, MD, and colleagues from the University of Florida College of Medicine in Gainesville. “In the absence of an understanding of the pathogenesis of CE and its prevention, emphasis must be on early recognition of the disease to permit quick intervention, with the hope of reducing morbidity and mortality.”

The authors reviewed a training sample of 26 occurrences of DKA complicated by severe CE and 69 episodes of uncomplicated DKA, along with head computed tomograms (CTs), and they incorporated signs of neurologic disease into a bedside evaluation protocol. They then applied this protocol to an independent test sample of 17 patients previously reported to have developed symptomatic CE during treatment for DKA.

The protocol was 92% sensitive and 96% specific for diagnosing CE sufficiently early for intervention. Two temporal patterns of diagnostic criteria defined early- and late-onset CE. Initial CTs were often normal, but sometimes showed diffuse CE. Focal brain injury on CT occurred only in patients with early onset of abnormal neurologic signs. Children often had clinically relevant signs of neurologic compromise, such as incontinence, vomiting, headache, or heart rate deceleration), despite minimal or no changes in Glasgow coma scale score.

Study limitations include examination of predominantly litigated case subjects with CE, inability to define the minimum duration that a sign or symptom must be present to make the diagnosis of CE, and lack of a more rigorous method to determine the risk associated with various signs.

Potential difficulties with this approach include the need for frequent and skilled nursing assessments, a tertiary or special care setting to ensure the immediate availability of pediatric specialists, and education of nurses regarding the importance of neurologic monitoring of children with DKA.

Other problems with application of the suggested clinical criteria are inability to rely solely on the Glasgow coma scale, and unnecessary treatment of some children. Based on the protocol’s positive predictive value, five children will be treated for every one who is likely to progress to a poor outcome if left untreated.

“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,” the authors write. “The diagnostic criteria for CE proposed in this study require prospective validation before they can be considered the standard of care. For now, they provide the first practical, evidence-based approach to the bedside diagnosis of CE in children with DKA.”
Diabetes Care. 2004;27:1541-1546