Stability of refrigerated whole blood samples for osmotic fragility test

ABSTRACT Background: The osmotic fragility test (OFT), conventionally used for assisting the diagnosis of many erythrocyte disorders, is a manual and time-consuming analysis not daily performed in many medical laboratories. This study was aimed at defining the stability of whole blood samples used for assessing erythrocyte osmotic resistance. Methods: Twenty-one consecutive routine whole blood samples collected into 5.4 mg K2EDTA were tested immediately after collection (day 0) and at different time intervals afterward (day 1, 2, 3, 4, 7, 10 and 14) after storage at 4 °C. The OFT was performed with the Osmored Monotest (1.3% glycerol; Eurospital, Trieste, Italy). Results at the different time points were compared with those obtained at day 0 and with the reference change value (i.e., 33%). Results: The median value of both hyperosmolar and hyposmolar resistance increased from baseline, reaching statistical significance at day 7 for hyperosmolar resistance and at day 1 for hyposmolar resistance, respectively. The median relative increase of hemolysis percentage values become greater than the reference change value at day 3 for hyposmolar resistance, while this limit was never overcome for hyperosmolar resistance. A significant inverse association was found between the mean increase in hyperosmolar resistance and the baseline value of hyperosmolar resistance (r = −0.92), mean corpuscular volume (MCV; r = −0.46) or mean corpuscular hemoglobin (MCH; r = −0.44), as well as between the mean increase in hyposmolar resistance and the baseline value of hyposmolar resistance (r = −0.86), or patient age (r = −0.56). Conclusions: The sample stability seems critical for the OFT. Whole blood specimens should not be stored refrigerated at 4 °C for >2 days before testing.

Patient posture for blood collection by venipuncture: recall for standardization after 28 years

ABSTRACT Background: Although data about the effect of posture on routine hematological testing were published 28 years ago, this pre-analytical issue has not been standardized so far. This study was planned to evaluate whether postural changes influence the results of hematology testing. Methods: A complete blood count was performed in 19 healthy volunteers after 25 min in the supine position, 20 min in a sitting position and 20 min stationary standing in an upright position. Results: The change from supine to sitting position caused clinically significant increases in the hemoglobin, hematocrit and red blood cell count. Furthermore, the change from supine to standing caused clinically significant increases in the hemoglobin, hematocrit, red blood cell, leukocyte, neutrophil, lymphocyte, basophil and platelet counts, and mean platelet volume, and that from sitting to standing caused clinically significant increases in hemoglobin, hematocrit, and red blood cell, leukocyte, neutrophil and lymphocyte counts. Conclusion: The results of this investigation provide further support to the notion that effort should be made to achieve widespread standardization in the practice of phlebotomy, including patient posture.

Assessment of blood sample stability for complete blood count using the Sysmex XN-9000 and Mindray BC-6800 analyzers

Background: Different hematological analyzers have different analytical performances that are often reflected in the criteria for sample stability of the complete blood count. This study aimed to assess the stability of several hematological parameters using the XN-9000 Sysmex and BC-6800 Mindray analyzers. Methods: The impact of storage at room temperature and 4 ◦C was evaluated after 2, 4, 6, 8, 24, 36 and 48h using ten normal and 40 abnormal blood samples. The variation from the baseline measurement was evaluated by the Steel­Dwass­Critchlow­Fligner test and by Bland­Altman plots, using quality specifications and critical difference as the total allowable variation. Results: Red blood cells and reticulocyte parameters (i.e. hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration, red blood cell distribution width, immature reticulocyte fractions, low-fluorescence reticulocytes, middle-fluorescence reticulocytes, high fluorescence mononuclear cells) showed less stability compared to leukocyte and platelet parameters (except for monocyte count and mean platelet volume). The bias for hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration and red blood cell distribution width coefficient of variation was higher than the critical difference after 8h using both analyzers. Conclusion: Blood samples measured with both analyzers do not show analytically signifi- cant changes in up to 2h of storage at room temperature and 4 ◦C. However, the maximum time for analysis can be extended for up to 8h when the bias is compared to the critical difference

Serum bilirubin value predicts hospital admission in carbon monoxide-poisoned patients. Active player or simple bystander?

OBJECTIVES:Although carbon monoxide poisoning is a major medical emergency, the armamentarium of recognized prognostic biomarkers displays unsatisfactory diagnostic performance for predicting cumulative endpoints.METHODS:We performed a retrospective and observational study to identify all patients admitted for carbon monoxide poisoning during a 2-year period. Complete demographical and clinical information, along with the laboratory data regarding arterial carboxyhemoglobin, hemoglobin, blood lactate and total serum bilirubin, was retrieved.RESULTS:The study population consisted of 38 poisoned patients (23 females and 15 males; mean age 39±21 years). Compared with discharged subjects, hospitalized patients displayed significantly higher values for blood lactate and total serum bilirubin, whereas arterial carboxyhemoglobin and hemoglobin did not differ. In a univariate analysis, hospitalization was significantly associated with blood lactate and total serum bilirubin, but not with age, sex, hemoglobin or carboxyhemoglobin. The diagnostic performance obtained after combining the blood lactate and total serum bilirubin results (area under the curve, 0.90; 95% CI, 0.81-0.99; p<0.001) was better than that obtained for either parameter alone.CONCLUSION:Although it remains unclear whether total serum bilirubin acts as an active player or a bystander, we conclude that the systematic assessment of bilirubin may, alongside lactate levels, provide useful information for clinical decision making regarding carbon monoxide poisoning.

Serum Potassium Levels Inversely Correlate with D-Dimer In Patients with Acute-Onset Atrial Fibrillation / Concentrações Séricas de Potássio Encontram-se Inversamente Correlacionadas aos Níveis de D-Dímero em Pacientes com Fibrilação Atrial Aguda

Background: D-dimer values are frequently increased in patients with atrial fibrillation (AF) compared to subjects in sinus rhythm. Hypokalemia plays a role in several cardiovascular diseases, but little is known about the association with AF. Objective: D-dimer values are frequently increased in patients with atrial fibrillation (AF) compared with subjects in sinus rhythm. Hypokalemia plays a role in several cardiovascular diseases, but little is known about the association with AF. The aim of this study was to investigate correlations between D-dimer and serum potassium in acute-onset AF (AAF). Methods: To investigate the potential correlation between the values of serum potassium and D-dimer in patients with AAF, we retrospectively reviewed clinical and laboratory data of all emergency department visits for AAF in 2013. Results: Among 271 consecutive AAF patients with D-dimer assessments, those with hypokalemia (n = 98) had significantly higher D-dimer values than normokalemic patients (139 versus 114 ng/mL, p = 0.004). The rate of patients with D-dimer values exceeding the diagnostic cut-off was higher in the group of patients with hypokalemia than in those with normal serum potassium (26.5% versus 16.2%; p = 0.029). An inverse and highly significant correlation was found between serum potassium and D-dimer (r = −0.21; p < 0.001), even after adjustments for age and sex (beta coefficient −94.8; p = 0.001). The relative risk for a positive D-dimer value attributed to hypokalemia was 1.64 (95% CI, 1.02 to 2.63; p = 0.040). The correlation remained statistically significant in patients free from antihypertensive drugs (r = −0.25; p = 0.018), but not in those taking angiotensin-receptor blockers, angiotensin-converting enzyme inhibitors, or diuretics. Conclusions: The inverse correlation between values of potassium and D-dimer in patients with AAF provides important and complementary information about the thromboembolic ...

Fundamento: Valores de D-dímero são frequentemente aumentada em pacientes com fibrilação atrial (FA) em comparação com indivíduos em ritmo sinusal. A hipocalemia desempenha um papel em várias doenças cardiovasculares, mas pouco se sabe sobre a associação com FA. Objetivo: As concentrações de D-dímero encontram-se frequentemente aumentadas em pacientes com FA, quando comparados com indivíduos em ritmo sinusal. A hipopotassemia desempenha um papel importante nas doenças cardiovasculares, porém, pouco é conhecido sobre sua associação com a FA. O objetivo deste estudo foi investigar a correlação entre os níveis séricos de D-dímero e potássio na FA aguda (FAA). Métodos: Para investigar a existência de uma potencial correlação entre os níveis séricos de potássio e D-dímero em pacientes com FAA, realizamos uma revisão retrospectiva de dados clínicos e laboratoriais relacionados a todas as visitas ao departamento de emergência devido à FAA, no ano de 2013. Resultados: Entre os 271 pacientes com FAA, aqueles com hipopotassemia (n = 98) mostraram aumento significativo nos níveis de D-dímero, quando comparados com pacientes com concentrações normais de potássio (139 versus 114 ng/mL, p = 0,004). A taxa de pacientes com níveis de D-dímero excedendo o valor limiar de diagnóstico foi maior no grupo de pacientes com hipopotassemia, quando comparado com o grupo de pacientes com concentrações normais de potássio (26,5% versus 16,2%; p = 0,029). Detectamos uma correlação inversa e altamente significativa entre os níveis séricos de potássio e D-dímero (r = -0,21; p < 0,001), até mesmo após ajuste para idade e sexo (coeficiente beta –94,8; p = 0,001). O risco relativo de um valor positivo de D-dímero estar relacionado à hipopotassemia foi de 1,64 (95% CI, 1,02 to 2,63; p = 0,040). A correlação permaneceu estatisticamente significativa em pacientes livres de medicamentos hipertensivos (r = -0,25; p = 0,018), porém não nos pacientes em tratamento ...

Emergency physician's perception of cultural and linguistic barriers in immigrant care: results of a multiple-choice questionnaire in a large Italian urban emergency department / 世界急诊医学杂志（英文）

@#BACKGROUND: A poor communication with immigrants can lead to inappropriate use of healthcare services, greater risk of misdiagnosis, and lower compliance with treatment. As precise information about communication between emergency physicians (EPs) and immigrants is lacking, we analyzed difficulties in communicating with immigrants in the emergency department (ED) and their possible associations with demographic data, geographical origin and clinical characteristics. METHODS: In an ED with approximately 85000 visits per year, a multiple-choice questionnaire was given to the EPs 4 months after discharge of each immigrant in 2011. RESULTS: Linguistic comprehension was optimal or partial in the majority of patients. Significant barriers were noted in nearly one fourth of patients, for only half of them compatriots who were able to translate. Linguistic barriers were mainly found in older and sicker patients; they were also frequently seen in patients coming from western Africa and southern Europe. Non-linguistic barriers were perceived by EPs in a minority of patients, more frequently in the elderly and frequent attenders. Factors independently associated with a poor final comprehension led to linguistic barriers, non-linguistic obstacles, the absence of intermediaries, and the presence of patient's fear and hostility. The latter probably is a consequence, not the cause, of a poor comprehension. CONCLUSION: Linguistic and non-linguistic barriers, although quite infrequent, are the main factors that compromise communication with immigrants in the ED, with negative effects especially on elderly and more seriously ill patients as well as on physician satisfaction and appropriateness in using services.

B-type Natriuretic Peptide May be Unsuitable for Diagnosing Central.

We describe a case of a 90-year-old male admitted to the emergency department with deep vein thrombosis and central acute pulmonary embolism. Despite a remarkably increased value of D-dimer and a modestly elevated concentration of cardiac troponin I, the value of B-type natriuretic peptide was found to be non-diagnostic. Limited to this single case report, our evidence suggests that the measurement of natriuretic peptides is questionable for diagnosing central acute pulmonary embolism in the emergency department.