Blood gas testing and related measurements: National recommendations on behalf of the Croatian Society of Medical Biochemistry and Laboratory Medicine.

Blood gas analysis (BGA) is exposed to risks of errors caused by improper sampling, transport and storage conditions. The Clinical and Laboratory Standards Institute (CLSI) generated documents with recommendations for avoidance of potential errors caused by sample mishandling. Two main documents related to BGA issued by the CLSI are GP43-A4 (former H11-A4) Procedures for the collection of arterial blood specimens; approved standard - fourth edition, and C46-A2 Blood gas and pH analysis and related measurements; approved guideline - second edition. Practices related to processing of blood gas samples are not standardized in the Republic of Croatia. Each institution has its own protocol for ordering, collection and analysis of blood gases. Although many laboratories use state of the art analyzers, still many preanalytical procedures remain unchanged. The objective of the Croatian Society of Medical Biochemistry and Laboratory Medicine (CSMBLM) is to standardize the procedures for BGA based on CLSI recommendations. The Working Group for Blood Gas Testing as part of the Committee for the Scientific Professional Development of the CSMBLM prepared a set of recommended protocols for sampling, transport, storage and processing of blood gas samples based on relevant CLSI documents, relevant literature search and on the results of Croatian survey study on practices and policies in acid-base testing. Recommendations are intended for laboratory professionals and all healthcare workers involved in blood gas processing.

Signal hyperintensities on brain magnetic resonance imaging in patients with primary Sjögren syndrome and frequent episodic tension-type headache: relation to platelet serotonin level and disease activity.

OBJECTIVE: To examine differences in number and size of signal hyperintensities (SH) on magnetic resonance imaging (MRI) between patients with primary Sjögren syndrome (pSS) and controls who all had frequent episodic tension-type headache (FETH), and to investigate their relation to platelet serotonin level (PSL), patient age, disease duration, and activity. METHODS: SH in 22 pSS patients with FETH were compared to 20 aged-matched controls with FETH, using the modified semiquantitative rating scale. Spectrofluorimetry was used for determination of PSL, and the European League Against Rheumatism SS Disease Activity Index (ESSDAI) for disease activity assessment. RESULTS: Statistically significant differences in the total number of SH were noted infratentorially (p = 0.025) and in the basal ganglia for lesions of diameter > 5 mm (p = 0.048). Significant correlations were found between disease duration and number of overall lesions > 5 mm (p = 0.04) and subcortical lesions of diameter 2-5 mm (p = 0.035). Number of periventricular SH inversely correlated to PSL (p = 0.019) and to patient age (p = 0.004), without association with markers of immunoinflammation and ESSDAI. CONCLUSION: Our study showed that SH on brain MRI are more common in specific regions of the brain in pSS patients with FETH than in controls with FETH, signifying a more widespread cerebral vasculopathy in SS patients with FETH. Periventricular SH seem to be associated to increased platelet serotonin release in pSS patients with FETH and correlated with disease duration, without correlation to the actual ESSDAI and markers of immunoinflammation, and might be linked with chronic immunoinflammation of low-grade intensity and vasculitis in pSS.