Intubation Decision Based on Illness Severity and Mortality in COVID-19: An International Study.

OBJECTIVES: To evaluate the impact of intubation timing, guided by severity criteria, on mortality in critically ill COVID-19 patients, amidst existing uncertainties regarding optimal intubation practices. DESIGN: Prospective, multicenter, observational study conducted from February 1, 2020, to November 1, 2022. SETTING: Ten academic institutions in the United States and Europe. PATIENTS: Adults (≥ 18 yr old) confirmed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and hospitalized specifically for COVID-19, requiring intubation postadmission. Exclusion criteria included patients hospitalized for non-COVID-19 reasons despite a positive SARS-CoV-2 test. INTERVENTIONS: Early invasive mechanical ventilation (EIMV) was defined as intubation in patients with less severe organ dysfunction (Sequential Organ Failure Assessment [SOFA] < 7 or Pa o2 /F io2 ratio > 250), whereas late invasive mechanical ventilation (LIMV) was defined as intubation in patients with SOFA greater than or equal to 7 and Pa o2 /F io2 ratio less than or equal to 250. MEASUREMENTS AND MAIN RESULTS: The primary outcome was mortality within 30 days of hospital admission. Among 4464 patients, 854 (19.1%) required mechanical ventilation (mean age 60 yr, 61.7% male, 19.3% Black). Of those, 621 (72.7%) were categorized in the EIMV group and 233 (27.3%) in the LIMV group. Death within 30 days after admission occurred in 278 patients (42.2%) in the EIMV and 88 patients (46.6%) in the LIMV group ( p = 0.28). An inverse probability-of-treatment weighting analysis revealed a statistically significant association with mortality, with patients in the EIMV group being 32% less likely to die either within 30 days of admission (adjusted hazard ratio [HR] 0.68; 95% CI, 0.52-0.90; p = 0.008) or within 30 days after intubation irrespective of its timing from admission (adjusted HR 0.70; 95% CI, 0.51-0.90; p = 0.006). CONCLUSIONS: In severe COVID-19 cases, an early intubation strategy, guided by specific severity criteria, is associated with a reduced risk of death. These findings underscore the importance of timely intervention based on objective severity assessments.

EFLM Task Force Preparation of Labs for Emergencies (TF-PLE) recommendations for reinforcing cyber-security and managing cyber-attacks in medical laboratories.

The healthcare systems are a prime target for cyber-attacks due to the sensitive nature of the information combined with the essential need for continuity of care. Medical laboratories are particularly vulnerable to cyber-attacks for a number of reasons, including the high level of information technology (IT), computerization and digitization. Based on reliable and widespread evidence that medical laboratories may be inadequately prepared for cyber-terrorism, a panel of experts of the Task Force Preparation of Labs for Emergencies (TF-PLE) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has recognized the need to provide some general guidance that could help medical laboratories to be less vulnerable and better prepared for the dramatic circumstance of a disruptive cyber-attack, issuing a number of consensus recommendations, which are summarized and described in this opinion paper.

Reliability of a point of care testing blood gas analyzer for measurement of lactate levels in cerebrospinal fluid.

Analysis of cerebrospinal fluid (CSF), including lactate, is key for diagnosis of acute meningitis. Since blood gas analyzers (BGA) enable rapid and safe blood-lactate measurements, we evaluated the reliability of RAPIDPoint 500 BGA to provide a fast and accurate measure of CSF lactate. In this study, CSF lactate levels were measured by a reference assay and on RAPIDPoint 500 BGA. Comparability was evaluated through difference analysis, using Bland Altman test, and linear regression analysis, using the Passing Bablok test. Agreement rate according to CSF lactate (≥3.5 and <3.5 mmol/L) was calculated using kappa (κ) statistic. Population study included 98 CSF samples. Concerning difference analysis, according to Bland-Altman test, bias was 0.13 mmol/L (CI 95%: -0.26 to 0.52 mmol/L. In regression analysis, according to Passing-Bablok equation a systematic difference between both assays was found. In concordance analysis, the interrate realibility was very high (κ: 0.964). According to our resuls, although a systematic difference was detected when lactate levels were measured on RAPIDPoint 500 BGA, the results from Bland-Altman test and the high agreement rate support that this POCT analyzer could be useful for a early and safe detection of patients with high probability of increased CSF lactate level.

Discriminative performance of pancreatic stone protein in predicting ICU mortality and infection severity in adult patients with infection: a systematic review and individual patient level meta-analysis.

BACKGROUND: Several studies suggested pancreatic stone protein (PSP) as a promising biomarker to predict mortality among patients with severe infection. The objective of the study was to evaluate the performance of PSP in predicting intensive care unit (ICU) mortality and infection severity among critically ill adults admitted to the hospital for infection. METHODS: A systematic search across Cochrane Central Register of Controlled Trials and MEDLINE databases (1966 to February 2022) for studies on PSP published in English using 'pancreatic stone protein', 'PSP', 'regenerative protein', 'lithostatin' combined with 'infection' and 'sepsis' found 46 records. The search was restricted to the five trials that measured PSP using the enzyme-linked immunosorbent assay technique (ELISA). We used Bayesian hierarchical regression models for pooled estimates and to predict mortality or disease severity using PSP, C-Reactive Protein (CRP) and procalcitonin (PCT) as main predictor. We used statistical discriminative measures, such as the area under the receiver operating characteristic curve (AUC) and classification plots. RESULTS: Among the 678 patients included, the pooled ICU mortality was 17.8% (95% prediction interval 4.1% to 54.6%) with a between-study heterogeneity (I-squared 87%). PSP was strongly associated with ICU mortality (OR = 2.7, 95% credible interval (CrI) [1.3-6.0] per one standard deviation increase; age, gender and sepsis severity adjusted OR = 1.5, 95% CrI [0.98-2.8]). The AUC was 0.69 for PSP 95% confidence interval (CI) [0.64-0.74], 0.61 [0.56-0.66] for PCT and 0.52 [0.47-0.57] for CRP. The sensitivity was 0.96, 0.52, 0.30 for risk thresholds 0.1, 0.2 and 0.3; respective false positive rate values were 0.84, 0.25, 0.10. CONCLUSIONS: We found that PSP showed a very good discriminative ability for both investigated study endpoints ICU mortality and infection severity; better in comparison to CRP, similar to PCT. Combinations of biomarkers did not improve their predictive ability.

Effects of Etomidate on Postintubation Hypotension, Inflammatory Markers, and Mortality in Critically Ill Patients with COVID-19: An International, Multicenter, Retrospective Study.

OBJECTIVE: To evaluate the association of etomidate with postintubation hypotension, inflammation, and mortality in critically ill patients with COVID-19. DESIGN: International, multicenter, retrospective study. PARTICIPANTS: Critically ill patients hospitalized specifically for COVID-19 from three major academic institutions in the US and Europe. MAIN OUTCOME AND MEASURES: Patients were allocated into the etomidate (ET) group or another induction agent (OA) group. The primary outcome was postintubation hypotension. Secondary outcomes included postintubation inflammatory status, in-hospital mortality, and mortality at 30 days. RESULTS: 171 patients with a median age of 68 (IQR 58-73) years were included (ET, n = 98; OA, n = 73). Etomidate was associated with lower postintubation mean arterial pressure [74.33 (64-85) mm Hg versus 81.84 (69.75-94.25) mm Hg, p = 0.005] compared to other agents. No statistically significant differences were generally observed in inflammatory markers between the two groups at 7- and 14-days after admission to the intensive care unit. In-hospital mortality [77 (79%) versus 41 (56%), p = 0.003] and mortality at 30-days [78 (80%) versus 43 (59%), p = 0.006] were higher in the ET group. In multivariate logistic regression analysis, only etomidate (p = 0.009) and postintubation mean arterial pressure (p < 0.001) had a statistically significant effect on mortality, in contrast to stress-dose steroids (p = 0.301), after adjusting for creatinine (p = 0.695), blood urea nitrogen (p = 0.153), age (p = 0.055), oxygen saturation of hemoglobin (SpO2) (p = 0.941), and fraction of inspired oxygen (FiO2) (p = 0.712). CONCLUSIONS: Administration of a single-bolus dose of etomidate in critically ill patients with COVID-19 is associated with lower postintubation mean arterial pressure and higher in-hospital and 30-day mortality compared to other induction agents.

Circulating suPAR associates with severity and in-hospital progression of COVID-19.

BACKGROUND: COVID-19 disease progression is characterized by hyperinflammation and risk stratification may aid in early aggressive treatment and advanced planning. The aim of this study was to assess whether suPAR and other markers measured at hospital admission can predict the severity of COVID-19. METHODS: The primary outcome measure in this international, multi-centre, prospective, observational study with adult patients hospitalized primarily for COVID-19 was the association of WHO Clinical Progression Scale (WHO-CPS) with suPAR, ferritin, CRP, albumin, LDH, eGFR, age, procalcitonin, and interleukin-6. Admission plasma suPAR levels were determined using the suPARnostic® ELISA and suPARnostic® Turbilatex assays. RESULTS: Seven hundred and sixty-seven patients, 440 (57.4%) males and 327 (42.6%) females, were included with a median age of 64 years. Log-suPAR levels significantly correlated with WHO-CPS score, with each doubling of suPAR increasing the score by one point (p < .001). All the other markers were also correlated with WHO-CPS score. Admission suPAR levels were significantly lower in survivors (7.10 vs. 9.63, 95% CI 1.47-3.59, p < .001). A linear model (SALGA) including suPAR, serum albumin, serum lactate dehydrogenase, eGFR, and age can best estimate the WHO-CPS score and survival. Combining all five parameters in the SALGA model can improve the accuracy of discrimination with an AUC of 0.80 (95% CI: 0.759-0.836). CONCLUSIONS: suPAR levels significantly correlated with WHO-CPS score, with each doubling of suPAR increasing the score by one point. The SALGA model may serve as a quick tool for predicting disease severity and survival at admission.

Identification of COVID-19 patients at risk of hospital admission and mortality: a European multicentre retrospective analysis of mid-regional pro-adrenomedullin.

BACKGROUND: Mid-Regional pro-Adrenomedullin (MR-proADM) is an inflammatory biomarker that improves the prognostic assessment of patients with sepsis, septic shock and organ failure. Previous studies of MR-proADM have primarily focussed on bacterial infections. A limited number of small and monocentric studies have examined MR-proADM as a prognostic factor in patients infected with SARS-CoV-2, however there is need for multicenter validation. An evaluation of its utility in predicting need for hospitalisation in viral infections was also performed. METHODS: An observational retrospective analysis of 1861 patients, with SARS-CoV-2 confirmed by RT-qPCR, from 10 hospitals across Europe was performed. Biomarkers, taken upon presentation to Emergency Departments (ED), clinical scores, patient demographics and outcomes were collected. Multiclass random forest classifier models were generated as well as calculation of area under the curve analysis. The primary endpoint was hospital admission with and without death. RESULTS: Patients suitable for safe discharge from Emergency Departments could be identified through an MR-proADM value of ≤ 1.02 nmol/L in combination with a CRP (C-Reactive Protein) of ≤ 20.2 mg/L and age ≤ 64, or in combination with a SOFA (Sequential Organ Failure Assessment) score < 2 if MR-proADM was ≤ 0.83 nmol/L regardless of age. Those at an increased risk of mortality could be identified upon presentation to secondary care with an MR-proADM value of > 0.85 nmol/L, in combination with a SOFA score ≥ 2 and LDH > 720 U/L, or in combination with a CRP > 29.26 mg/L and age ≤ 64, when MR-proADM was > 1.02 nmol/L. CONCLUSIONS: This international study suggests that for patients presenting to the ED with confirmed SARS-CoV-2 infection, MR-proADM in combination with age and CRP or with the patient's SOFA score could identify patients at low risk where outpatient treatment may be safe.

Circulating levels of calprotectin, a signature of neutrophil activation in prediction of severe respiratory failure in COVID-19 patients: a multicenter, prospective study (CalCov study).

OBJECTIVE: Severe COVID-19 is characterized by a dysregulated immune response in which neutrophils play a critical role. Calprotectin reflects neutrophil activation and is involved in the self-amplifying thrombo-inflammatory storm in severe COVID-19. We aimed to evaluate the role of calprotectin in early prediction of severity in COVID-19 patients. METHODS: This was a multicenter prospective observational study enrolling consecutive adult COVID-19 patients. On arrival to emergency department, blood samples were collected for laboratory tests, including serum calprotectin. The primary outcome was severe respiratory failure requiring invasive mechanical ventilation and the secondary outcome was need for Intensive Care Unit (ICU) admission. RESULTS: Study population included 395 patients, 57 (14.4%) required invasive mechanical ventilation and 100 (25.3%) were admitted to ICU. Median serum calprotectin levels were significantly higher in intubated (3.73 mg/L vs. 2.63 mg/L; p < 0.001) and ICU patients (3.48 mg/L vs. 2.60 mg/L; p = 0.001). Calprotectin showed a significant accuracy to predict the need for invasive mechanical ventilation (ROC AUC 0.723) and ICU admission (ROC AUC 0.650). In multivariate analysis, serum calprotectin was an independent predictor of invasive mechanical ventilation (OR 1.161) and ICU admission (OR 1.068). CONCLUSION: Serum calprotectin can be used as an early predictor of severity in COVID-19 patients.

Role of Pancreatic Stone Protein as an Early Biomarker for Risk Stratification of Acute Pancreatitis.

BACKGROUND: Early risk stratification of acute pancreatitis is crucial to improve clinical outcomes. The objective of this study was to evaluate the ability of pancreatic stone protein (PSP) to predict acute pancreatitis severity and to compare it with the biomarkers and severity scores currently used for that purpose. PATIENTS AND METHODS: Prospective single-center observational study enrolling 268 adult patients with acute pancreatitis. Biomarkers including PSP were measured upon admission to the Emergency Department and severity scores as SOFA, PANC-3, and BISAP were computed. Patients were classified into mild-moderate (non-severe) and severe acute pancreatitis according to the Determinant-Based Classification Criteria. Area under the curve (AUC) and regression analysis were used to analyze the discrimination abilities and the association of biomarkers and scores with severity. RESULTS: Two hundred and thirty-five patients (87.7%) were classified as non-severe and 33 (12.3%) as severe acute pancreatitis. Median [IQR] PSP was increased in patients with severe acute pancreatitis (890 µg/L [559-1142] vs. 279 µg/L [141-496]; p < 0.001) and it was the best predictor (ROC AUC: 0.827). In multivariate analysis, PSP and urea were the only independent predictors for severe acute pancreatitis and a model combining them both ("biomarker model") showed an AUC of 0.841 for prediction of severe acute pancreatitis, higher than the other severity scores. CONCLUSIONS: PSP is a promising biomarker for predicting the severity of acute pancreatitis upon admission. A model combining PSP and urea might further constitute a potential tool for early risk stratification of this disease.

Harmonized D-dimer levels upon admission for prognosis of COVID-19 severity: Results from a Spanish multicenter registry (BIOCOVID-Spain study).

Coagulopathy is a key feature of COVID-19 and D-dimer has been reported as a predictor of severity. However, because D-dimer test results vary considerably among assays, resolving harmonization issues is fundamental to translate findings into clinical practice. In this retrospective multicenter study (BIOCOVID study), we aimed to analyze the value of harmonized D-dimer levels upon admission for the prediction of in-hospital mortality in COVID-19 patients. All-cause in-hospital mortality was defined as endpoint. For harmonization of D-dimer levels, we designed a model based on the transformation of method-specific regression lines to a reference regression line. The ability of D-dimer for prediction of death was explored by receiver operating characteristic curves analysis and the association with the endpoint by Cox regression analysis. Study population included 2663 patients. In-hospital mortality rate was 14.3%. Harmonized D-dimer upon admission yielded an area under the curve of 0.66, with an optimal cut-off value of 0.945 mg/L FEU. Patients with harmonized D-dimer ≥ 0.945 mg/L FEU had a higher mortality rate (22.4% vs. 9.2%; p < 0.001). D-dimer was an independent predictor of in-hospital mortality, with an adjusted hazard ratio of 1.709. This is the first study in which a harmonization approach was performed to assure comparability of D-dimer levels measured by different assays. Elevated D-dimer levels upon admission were associated with a greater risk of in-hospital mortality among COVID-19 patients, but had limited performance as prognostic test.

MR-proADM as marker of endotheliitis predicts COVID-19 severity.

BACKGROUND: Early identification of patients at high risk of progression to severe COVID-19 constituted an unsolved challenge. Although growing evidence demonstrates a direct association between endotheliitis and severe COVID-19, the role of endothelial damage biomarkers has been scarcely studied. We investigated the relationship between circulating mid-regional proadrenomedullin (MR-proADM) levels, a biomarker of endothelial dysfunction, and prognosis of SARS-CoV-2-infected patients. METHODS: Prospective observational study enrolling adult patients with confirmed COVID-19. On admission to emergency department, a blood sample was drawn for laboratory test analysis. Primary and secondary endpoints were 28-day all-cause mortality and severe COVID-19 progression. Area under the curve (AUC) and multivariate regression analysis were employed to assess the association of the biomarker with the established endpoints. RESULTS: A total of 99 patients were enrolled. During hospitalization, 25 (25.3%) cases progressed to severe disease and the 28-day mortality rate was of 14.1%. MR-proADM showed the highest AUC to predict 28-day mortality (0.905; [CI] 95%: 0.829-0.955; P < .001) and progression to severe disease (0.829; [CI] 95%: 0.740-0.897; P < .001), respectively. MR-proADM plasma levels above optimal cut-off (1.01 nmol/L) showed the strongest independent association with 28-day mortality risk (hazard ratio [HR]: 10.470, 95% CI: 2.066-53.049; P < .005) and with progression to severe disease (HR: 6.803, 95% CI: 1.458-31.750; P = .015). CONCLUSION: Mid-regional proadrenomedullin was the biomarker with highest performance for prognosis of death and progression to severe disease in COVID-19 patients and represents a promising predictor for both outcomes, which might constitute a potential tool in the assessment of prognosis in early stages of this disease.

Cardiac troponin and COVID-19 severity: Results from BIOCOVID study.

BACKGROUND: Myocardial injury is a common finding in COVID-19 strongly associated with severity. We analysed the prevalence and prognostic utility of myocardial injury, characterized by elevated cardiac troponin, in a large population of COVID-19 patients, and further evaluated separately the role of troponin T and I. METHODS: This is a multicentre, retrospective observational study enrolling patients with laboratory-confirmed COVID-19 who were hospitalized in 32 Spanish hospitals. Elevated troponin levels were defined as values above the sex-specific 99th percentile upper reference limit, as recommended by international guidelines. Thirty-day mortality was defined as endpoint. RESULTS: A total of 1280 COVID-19 patients were included in this study, of whom 187 (14.6%) died during the hospitalization. Using a nonspecific sex cut-off, elevated troponin levels were found in 344 patients (26.9%), increasing to 384 (30.0%) when a sex-specific cut-off was used. This prevalence was significantly higher (42.9% vs 21.9%; P < .001) in patients in whom troponin T was measured in comparison with troponin I. Sex-specific elevated troponin levels were significantly associated with 30-day mortality, with adjusted odds ratios (ORs) of 3.00 for total population, 3.20 for cardiac troponin T and 3.69 for cardiac troponin I. CONCLUSION: In this multicentre study, myocardial injury was a common finding in COVID-19 patients. Its prevalence increased when a sex-specific cut-off and cardiac troponin T were used. Elevated troponin was an independent predictor of 30-day mortality, irrespective of cardiac troponin assay and cut-offs to detect myocardial injury. Hence, the early measurement of cardiac troponin may be useful for risk stratification in COVID-19.

Accuracy of pancreatic stone protein for the diagnosis of infection in hospitalized adults: a systematic review and individual patient level meta-analysis.

BACKGROUND: Accurate biomarkers to diagnose infection are lacking. Studies reported good performance of pancreatic stone protein (PSP) to detect infection. The objective of the study was to determine the performance of PSP in diagnosing infection across hospitalized patients and calculate a threshold value for that purpose. METHODS: A systematic search across Cochrane Central Register of Controlled Trials and MEDLINE databases (1966-March 2019) for studies on PSP published in English using 'pancreatic stone protein', 'PSP', 'regenerative protein', 'lithostatin' combined with 'infection' and 'sepsis' found 44 records. The search was restricted to the five trials that evaluated PSP for the initial detection of infection in hospitalized adults. Individual patient data were obtained from the investigators of all eligible trials. Data quality and validity was assessed according to PRISMA guidelines. We choose a fixed-effect model to calculate the PSP cut-off value that best discriminates infected from non-infected patients. RESULTS: Infection was confirmed in 371 of 631 patients. The median (IQR) PSP value of infected versus uninfected patients was 81.5 (30.0-237.5) versus 19.2 (12.6-33.57) ng/ml, compared to 150 (82.70-229.55) versus 58.25 (15.85-120) mg/l for C-reactive protein (CRP) and 0.9 (0.29-4.4) versus 0.15 (0.08-0.5) ng/ml for procalcitonin (PCT). Using a PSP cut-off of 44.18 ng/ml, the ROC AUC to detect infection was 0.81 (0.78-0.85) with a sensitivity of 0.66 (0.61-0.71), specificity of 0.83 (0.78-0.88), PPV of 0.85 (0.81-0.89) and NPV of 0.63 (0.58-0.68). When a model combining PSP and CRP was used, the ROC AUC improved to 0.90 (0.87-0.92) with higher sensitivity 0.81 (0.77-0.85) and specificity 0.84 (0.79-0.90) for discriminating infection from non-infection. Adding PCT did not improve the performance further. CONCLUSIONS: PSP is a promising biomarker to diagnose infections in hospitalized patients. Using a cut-off value of 44.18 ng/ml, PSP performs better than CRP or PCT across the considered studies. The combination of PSP with CRP further enhances its accuracy.

Characteristics and laboratory findings on admission to the emergency department among 2873 hospitalized patients with COVID-19: the impact of adjusted laboratory tests in multicenter studies. A multicenter study in Spain (BIOCOVID-Spain study).

Identification of predictors for severe disease progression is key for risk stratification in COVID-19 patients. We aimed to describe the main characteristics and identify the early predictors for severe outcomes among hospitalized patients with COVID-19 in Spain. This was an observational, retrospective cohort study (BIOCOVID-Spain study) including COVID-19 patients admitted to 32 Spanish hospitals. Demographics, comorbidities and laboratory tests were collected. Outcome was in-hospital mortality. For analysis, laboratory tests values were previously adjusted to assure the comparability of results among participants. Cox regression was performed to identify predictors. Study population included 2873 hospitalized COVID-19 patients. Nine variables were independent predictors for in-hospital mortality, including creatinine (Hazard ratio [HR]:1.327; 95% Confidence Interval [CI]: 1.040-1.695, p = .023), troponin (HR: 2.150; 95% CI: 1.155-4.001; p = .016), platelet count (HR: 0.994; 95% CI: 0.989-0.998; p = .004) and C-reactive protein (HR: 1.037; 95% CI: 1.006-1.068; p = .019). This is the first multicenter study in which an effort was carried out to adjust the results of laboratory tests measured with different methodologies to guarantee their comparability. We reported a comprehensive information about characteristics in a large cohort of hospitalized COVID-19 patients, focusing on the analytical features. Our findings may help to identify patients early at a higher risk for an adverse outcome.

Analyzing the capability of PSP, PCT and sCD25 to support the diagnosis of infection in cancer patients with febrile neutropenia.

Background Early diagnosis of infection is essential for the initial management of cancer patients with chemotherapy-associated febrile neutropenia (FN). In this study, we have evaluated two emerging infection biomarkers, pancreatic stone protein (PSP) and soluble receptor of interleukin 2, known as soluble cluster of differentiation 25 (sCD25), for the detection of an infectious cause in FN, in comparison with other commonly used infection biomarkers, such as procalcitonin (PCT). Methods A total of 105 cancer patients presenting to the emergency department were prospectively enrolled. We observed 114 episodes of chemotherapy-associated FN. At presentation, a blood sample was collected for the measurement of PCT, PSP and sCD25. In order to evaluate the discriminatory ability of these markers for the diagnosis of infection, the area under the curve (AUC) of the receiver operating characteristic curves was calculated. Results Infection was documented in 59 FN episodes. PCT, PSP and sCD25 levels were significantly higher in infected patients. PCT was the biomarker with the highest diagnostic accuracy for infection (AUC: 0.901), whereas PSP and sCD25 showed a similar performance, with AUCs of 0.751 and 0.730, respectively. In a multivariable analysis, PCT and sCD25 were shown to be independently associated with infection. Conclusions Two novel biomarkers, PSP and sCD25, correlated with infection in cancer patients with chemotherapy-associated FN, but neither PSP nor sCD25 improved the performance of PCT. Based on the results obtained, the introduction of these novel biomarkers as a tool for the diagnosis of infection in this patient group is not recommended.

In vitro stability of B-type natriuretic peptide (BNP) in plasma stored under different conditions when measured with the Lumipulse® assay.

Natriuretic peptides are a laboratory tool with significant implications for the diagnosis and prognosis of heart failure (HF). The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommended that assays must be examined for sample stability because there appears to be assay dependent. We aimed to evaluate the in vitro stability of B-type natriuretic peptide (BNP) under different handling conditions and using a BNP assay from Fujirebio Diagnostics (Tokyo, Japan). BNP concentrations were measured in plasma EDTA samples from 11 subjects to evaluate the in vitro stability at room temperature and at 4 °C and in 10 subjects to check the in vitro stability of samples stored at -20 °C during 1 and 3 months. Stability limit was defined according to Spanish Society of Laboratory Medicine (SEQC-ML) recommendations. At room temperature and 4 °C, BNP concentrations decreased progressively in samples collected in both groups, remaining stable within four hours from collection. BNP concentrations also were stable within four hours from collection in whole blood at room temperature. Finally, at -20 °C, BNP concentrations remained stable in both groups at 1 and 3 months, respectively. According to our results, BNP, stored at room temperature or at 4 °C, should be assayed in the first four hours after collection. Besides, BNP was shown to be stable in whole blood for at least four hours at room temperature. If the testing cannot be performed within the first four hours, the plasma should be frozen and kept at -20 °C for up to 3 months.

D-dimer during pregnancy: establishing trimester-specific reference intervals.

Pregnancy is associated with an increased risk of venous thromboembolism (VTE). D-dimer is a biomarker used as an exclusion criterion of VTE disease, but its usefulness during pregnancy shows limitations because D-dimer levels physiologically increase through pregnancy. The aim of our study was to follow the changes of D-dimer levels and to establish trimester-specific reference intervals during normal pregnancy. This is a longitudinal prospective study in which the reference population finally included 102 healthy pregnant women. Plasma D-dimer levels were measured during the three trimesters of pregnancy, using a latex-based immunoturbidimetric assay. Reference intervals were calculated according to the Clinical and Laboratory Standards Institute recommendations. D-dimer levels increased progressively and significantly through pregnancy and peaked in the third trimester, in which D-dimer levels were above the conventional cut-off point (500 µg/L) in 99% of pregnant women. The following reference intervals were defined: first trimester: 169-1202 µg/L, second trimester: 393-3258 µg/L and third trimester: 551-3333 µg/L. The study provides reference intervals of D-dimer during the pregnancy using latex-based immunoturbidimetry on the ACL 300 TOP automated coagulation analyser. Further prospective studies of pregnant women with clinical suspicion of VTE are needed to validate these results.

Pancreatic stone protein and soluble CD25 for infection and sepsis in an emergency department.

BACKGROUND: Infection is a common problem in emergency departments (EDs) and is associated with high mortality, morbidity and costs. Identifying infection in ED patients can be challenging. Biomarkers can facilitate its diagnosis, enabling an early management and improving outcomes. In the critical care setting, two emerging biomarkers, pancreatic stone protein (PSP) and soluble CD25 (sCD25), have demonstrated to be useful for diagnosis of sepsis. We aimed to assess the diagnostic value of these biomarkers, in comparison with procalcitonin (PCT), for infection and sepsis in an ED population with suspected infection. MATERIALS AND METHODS: Through a prospective, observational study, we investigated the utility of serum PCT, PSP and sCD25 levels, measured on admission, for diagnosis of infection and sepsis, defined according to the recently updated for sepsis (Sepsis-3), in patients presenting to the ED for suspected infection. Diagnostic accuracy was evaluated by using receiver operating characteristic curves (ROC) analysis. RESULTS: Of the 152 patients enrolled in this study, 129 had a final diagnosis of infection, including 82 with noncomplicated infection and 47 with sepsis. Median PCT, PSP and sCD25 levels were significantly higher in patients with infection and sepsis. The ROC curve analysis revealed a similar diagnostic accuracy for infection (ROC area under the curve (AUC) PCT: 0·904; sCD25: 0·869 and PSP: 0·839) and for sepsis (ROC AUC: PCT: 0·820; sCD25: 0·835 and PSP: 0·872). CONCLUSIONS: Pancreatic stone protein and sCD25 perform well as infection and sepsis biomarkers, with a similar performance than PCT, in ED patients with suspected infection. Further larger studies investigating use of PSP and sCD25 are needed.