Diagnostic testing for evaluation of brief resolved unexplained events.

BACKGROUND: Since the publication of the American Academy of Pediatrics (AAP) clinical practice guideline for brief resolved unexplained events (BRUEs), a few small, single-center studies have suggested low yield of diagnostic testing in infants presenting with such an event. We conducted this large retrospective multicenter study to determine the role of diagnostic testing in leading to a confirmatory diagnosis in BRUE patients. METHODS: Secondary analysis from a large multicenter cohort derived from 15 hospitals participating in the BRUE Quality Improvement and Research Collaborative. The study subjects were infants < 1 year of age presenting with a BRUE to the emergency departments (EDs) of these hospitals between October 1, 2015, and September 30, 2018. Potential BRUE cases were identified using a validated algorithm that relies on administrative data. Chart review was conducted to confirm study inclusion/exclusion, AAP risk criteria, final diagnosis, and contribution of test results. Findings were stratified by ED or hospital discharge and AAP risk criteria. For each patient, we identified whether any diagnostic test contributed to the final diagnosis. We distinguished true (contributory) results from false-positive results. RESULTS: Of 2036 patients meeting study criteria, 63.2% were hospitalized, 87.1% qualified as AAP higher risk, and 45.3% received an explanatory diagnosis. Overall, a laboratory test, imaging, or an ancillary test supported the final diagnosis in 3.2% (65/2036, 95% confidence interval [CI] 2.7%-4.4%) of patients. Out of 5163 diagnostic tests overall, 1.1% (33/2897, 95% CI 0.8%-1.5%) laboratory tests and 1.5% (33/2266, 95% CI 1.0%-1.9%) of imaging and ancillary studies contributed to a diagnosis. Although 861 electrocardiograms were performed, no new cardiac diagnoses were identified during the index visit. CONCLUSIONS: Diagnostic testing to explain BRUE including for those with AAP higher risk criteria is low yield and rarely contributes to an explanation. Future research is needed to evaluate the role of testing in more specific, at-risk populations.

Predictors of Primary Intracranial Hypertension in Children Using a Newly Suggested Opening Pressure Cutoff of 280 mm H2O.

OBJECTIVES: We assessed the clinical characteristics of primary intracranial hypertension (PIH) in children using a newly recommended threshold for cerebrospinal fluid opening pressure (280 mm H2O). METHOD: Cross-sectional study of patients age ≤21 years who had a lumbar puncture done for evaluation of PIH. Patients were excluded if lumbar puncture was done for a suspected infection, seizure, mental status changes, multiple sclerosis, or Guillain-Barre syndrome. Cases were identified using a text-search module followed by manual review. We performed χ2 analysis for categorical data and Mann-Whitney U test for continuous data, followed by a binary logistic regression. RESULTS: We identified 374 patients of whom 67% were female, median age was 13 years interquartile range (11 to 16 years), and admission rate was 24%. Using an opening pressure cutoff of 250 mm H2O, 127 patients (34%) were identified as having PIH, whereas using the new cutoff 105 patients (28%) met PIH criteria. Predictors for PIH included optic disc edema or sixth nerve palsy using both old, odds ratio (OR) 7.6 (4.3, 13.5), and new cutoffs, OR 9.7 (95% confidence interval 5.1, 18.5). Headache duration ≤61 days is predictive of PIH using the new cutoff OR 4.1 (95% confidence interval 1.3, 12.8). A model is presented which stratifies patients into groups with low (7%), medium (18%), and high (greater than 42%) risk of PIH. CONCLUSIONS: A higher cerebrospinal fluid opening pressure threshold in the criteria of PIH is associated with PIH patients with a different symptom profile. Children with optic disc edema, bulging fontanel or sixth nerve palsy, are at increased risk for PIH.

How Much Cerebrospinal Fluid Should We Remove Prior to Measuring a Closing Pressure?

OBJECTIVE: The objective of this study was to identify a relationship between cerebrospinal fluid (CSF) volume removal and change in CSF pressure in children with suspected idiopathic intracranial hypertension (IIH). METHODS: We performed a cross-sectional study of children 22 years and younger who underwent a lumbar puncture (LP) and had a documented opening pressure, closing pressure, and volume removed. Relationship between volume removal and pressure change was determined using a fractional polynomial regression procedure. RESULTS: In the 297 patients who met the inclusion criteria, CSF pressure decreased by 1 cm H2O for every 0.91 mL of CSF removed if the maximum change in pressure was less than 15 cm H2O ( R2 = 0.38). CONCLUSION: A linear relationship exists between the volume of CSF removed and the amount of pressure relieved when the desired pressure change is less than 15 cm H2O.