The impact of between analytical platform variability on the classification of pleural effusions into exudate or transudate using Light's criteria.

BACKGROUND: Light's criteria are ratios of pleural fluid to serum total protein (TP), pleural fluid to serum lactate dehydrogenase (LDH) and pleural fluid LDH to the upper reference limit for serum LDH. They are used to classify pleural effusions into an exudate or transudate when pleural fluid protein is 25-35 g/L. We evaluated the impact of between analytical platforms on the classification of pleural effusions using Light's criteria. METHODS: Light's criteria were used to classify pleural effusions with fluid TP between 25 and 35 g/L into exudate and transudate. LDH and TP were analysed using an Abbott ARCHITECT c16000 analyser using a lactate to pyruvate method for LDH and two Roche Cobas 800 c702 analysers, one using a lactate to pyruvate method (laboratory B) and one a lactate to pyruvate method (laboratory C). RESULTS: Eighty-three paired serum and pleural fluid samples were analysed. Of these, 44 samples had a pleural fluid TP between 25 and 35 g/L and were classified according to Light's criteria. Classification of pleural fluid into transudate or exudate using different analytical platforms was 82% concordant. The LDH ratio and TP ratio were similar in laboratory B and laboratory C, but these were respectively lower (p<0.001) and higher (p<0.001) than those at laboratory A. CONCLUSIONS: Although Light's criteria are ratios, which should minimise interassay variability, we report 18% discordance between different analytical platforms. The discordance was largely due to the performance of LDH and to a lesser extent protein assays in pleural fluid. Laboratories should be aware that assays may perform differently in serum and pleural fluid.

Screening for malnutrition in patients with gastro-entero-pancreatic neuroendocrine tumours: a cross-sectional study.

OBJECTIVES: To investigate whether screening for malnutrition using the validated malnutrition universal screening tool (MUST) identifies specific characteristics of patients at risk, in patients with gastro-entero-pancreatic neuroendocrine tumours (GEP-NET). DESIGN: Cross-sectional study. SETTING: University Hospitals Coventry & Warwickshire NHS Trust; European Neuroendocrine Tumour Society Centre of Excellence. PARTICIPANTS: Patients with confirmed GEP-NET (n=161) of varying primary tumour sites, functioning status, grading, staging and treatment modalities. MAIN OUTCOME MEASURE: To identify disease and treatment-related characteristics of patients with GEP-NET who score using MUST, and should be directed to detailed nutritional assessment. RESULTS: MUST score was positive (≥1) in 14% of outpatients with GEP-NET. MUST-positive patients had lower faecal elastase concentrations compared to MUST-negative patients (244±37 vs 383±20 µg/g stool; p=0.018), and were more likely to be on treatment with long-acting somatostatin analogues (65 vs 38%, p=0.021). MUST-positive patients were also more likely to have rectal or unknown primary NET, whereas, frequencies of other GEP-NET including pancreatic NET were comparable between MUST-positive and MUST-negative patients. CONCLUSIONS: Given the frequency of patients identified at malnutrition risk using MUST in our relatively large and diverse GEP-NET cohort and the clinical implications of detecting malnutrition early, we recommend routine use of malnutrition screening in all patients with GEP-NET, and particularly in patients who are treated with long-acting somatostatin analogues.

Garment fit and protection from sustained +Gz acceleration with 'full-coverage' anti-G trousers.

INTRODUCTION: Garment fit may influence the effectiveness with which Full-Coverage Anti-G Trousers (FCAGT) transmit pressure to the skin surface, and hence provide protection from sustained +Gz acceleration. A search of the available literature, however, did not reveal any prior work quantifying this effect. METHODS: Three related studies were performed. In Study I, using a mannequin, garment-to-surface pressure transmission ratios were measured at various locations under normally fitted (NF) and loosely fitted (LF) FCAGT. In Study II, garment pressure-volume ratios and lung volumes were measured at +1 Gz in six men wearing FCAGT in three conditions: NF, LF, or NF with inflatable socks at 13 kPa differential pressure (NF+SOCKS). In Study III, relaxed +Gz tolerance (RGT) and ratings of perceived exertion (RPE) at +7, +8, and +9 Gz were measured in eight men wearing FCAGT in four experimental conditions: NF; LF; abdomen LF, legs NF; or abdomen NF, legs LF. RESULTS: LF did not affect pressure transmission over the lower limbs or lower abdomen, but transmission over the upper abdomen was significantly compromised. Lung volumes were reduced with FCAGT inflation, but LF was associated with greater expiratory reserve volumes and increased FCAGT volume. Under +Gz acceleration, LF over the abdomen (with or without lower limb LF) decreased RGT and increased RPE, but not with lower limb LF when abdominal fit was normal. DISCUSSION: Care should be taken to achieve and maintain a snug FCAGT fit, especially of the abdominal portion of the FCAGT, to ensure optimal anti-G protection during sustained acceleration.