Data on the clinical, analytical, and laboratory factors associated with negative anion gaps at an academic medical center.

The anion gap is a calculated parameter derived from the difference between the major plasma cations and anions in serum/plasma or whole blood, with a widely used simple equation utilizing concentrations of sodium, chloride, and bicarbonate. While there is extensive literature on the clinical significance and causes of elevated anion gaps, there is comparatively less data on low anion gaps. Occasionally, anion gap calculations result in a negative number (-1 or less). From the published literature, causes of these 'negative anion gaps' include laboratory error, specimen contamination or interference, hypoalbuminemia, extreme hyperkalemia, bromism, and paraproteins from multiple myeloma or similar pathologic processes. The data in this article present results from retrospective review of clinical chemistry and blood gas analysis testing at an academic medical center. The data include electrolyte concentrations and anion gap values derived from a total of 2,948,574 specimens (2,841,863 serum/plasma specimens analyzed on Roche Diagnostics clinical chemistry analyzers, 93,987 whole blood specimens analyzed on Radiometer blood gas analyzers, and 12,724 whole blood specimens on point-of-care chemistry devices) from 371,925 unique patients, clinical area where testing was ordered (for serum/plasma samples), sex, and age. For serum/plasma specimens with a negative anion gap, the data additionally include information from detailed chart review of possible factors and disease conditions contributing to the negative anion gap, pattern of electrolyte abnormalities, presence or absence of hypoalbuminemia, and corrected anion gap (if hypoalbuminemia is present).

The Neuropathology of 1p36 Deletion Syndrome: An Autopsy Case Series.

1p36 deletion syndrome is the most common terminal deletion syndrome, manifesting clinically as abnormal facies and developmental delay with frequent cardiac, skeletal, urogenital, and renal abnormalities. Limited autopsy case reports describe the neuropathology of 1p36 deletion syndrome. The most extensive single case report described a spectrum of abnormalities, mostly related to abnormal neuronal migration. We report the largest published series of 1p36 autopsy cases, with an emphasis on neuropathologic findings. Our series consists of 3 patients: 2 infants (5-hours old and 23-days old) and 1 older child (11 years). Our patients showed abnormal cortical gyration together with a spectrum of neuronal migration abnormalities, including heterotopias and hippocampal abnormalities, as well as cerebellar hypoplasia. Our findings thus support the role of neuronal migration defects in the pathogenesis of cognitive defects in 1p36 deletion syndrome and broaden the reported neuropathologic spectrum of this common syndrome.

Frozen Section Quality Assurance.

OBJECTIVES: Composite frozen section turnaround time has limited value, precluding assessment of certain processes: slide preparation (technical) and diagnosis (interpretation). We examined whether measuring these elements could identify delays, hypothesizing that longer times were related to (1) inefficient technical processes and (2) case-specific diagnostic challenges. METHODS: Technical and interpretive times were determined for 1,992 specimens submitted for frozen section in 2017; the data were sorted by surgical specialty. Mean and quartile times were determined for each category with all specimens assessed equally, including those with multiple frozen section blocks. RESULTS: Technical times were significantly longer than interpretive times. Specialty grouping facilitated trend identification and enabled assessment of technical and interpretation challenges. We identified technical issues with certain gross specimens involving overdissection and interpretation delays for specific neoplasms and margins. CONCLUSIONS: Measuring technical and interpretative times and subcategorizing by specialty has aided the assessment of frozen section processing in our laboratory, enabling case isolation for process improvement.