Applicability of an unsupervised cluster model developed on first wave COVID-19 patients in second/third wave critically ill patients.

OBJECTIVE: To validate the unsupervised cluster model (USCM) developed during the first pandemic wave in a cohort of critically ill patients from the second and third pandemic waves. DESIGN: Observational, retrospective, multicentre study. SETTING: Intensive Care Unit (ICU). PATIENTS: Adult patients admitted with COVID-19 and respiratory failure during the second and third pandemic waves. INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: Collected data included demographic and clinical characteristics, comorbidities, laboratory tests and ICU outcomes. To validate our original USCM, we assigned a phenotype to each patient of the validation cohort. The performance of the classification was determined by Silhouette coefficient (SC) and general linear modelling. In a post-hoc analysis we developed and validated a USCM specific to the validation set. The model's performance was measured using accuracy test and area under curve (AUC) ROC. RESULTS: A total of 2330 patients (mean age 63 [53-82] years, 1643 (70.5%) male, median APACHE II score (12 [9-16]) and SOFA score (4 [3-6]) were included. The ICU mortality was 27.2%. The USCM classified patients into 3 clinical phenotypes: A (n = 1206 patients, 51.8%); B (n = 618 patients, 26.5%), and C (n = 506 patients, 21.7%). The characteristics of patients within each phenotype were significantly different from the original population. The SC was -0.007 and the inclusion of phenotype classification in a regression model did not improve the model performance (0.79 and 0.78 ROC for original and validation model). The post-hoc model performed better than the validation model (SC -0.08). CONCLUSION: Models developed using machine learning techniques during the first pandemic wave cannot be applied with adequate performance to patients admitted in subsequent waves without prior validation.

Clinical and Microbiological Risk Factors for 30-Day Mortality of Bloodstream Infections Caused by OXA-48-Producing Klebsiella pneumoniae.

Bloodstream infections (BSI) caused by carbapenem-resistant Klebsiella pneumoniae are associated with high morbidity and mortality, and the therapy options available for their treatment are frequently scarce. The aim of this study was to analyze risk factors for 30-day mortality in patients with BSI caused by OXA-48-producing K. pneumoniae. The clinical and treatment features of the patients, who attended a single hospital over a five-year period, were retrospectively reviewed. The microbiological features, including the sequence types (ST) and the somatic (O) and capsular (K) antigens, as well as their resistance properties, comprising phenotypes and genetic background, were also considered. To identify the risk factors for 30-day mortality, uni- and multivariate statistical analyses were performed. The univariate analysis revealed statistically significant correlations for age, male gender, lower respiratory system infection, infection by ST147 isolates, and infection by isolates expressing the K64 antigen. The multivariate analysis, applied to variables yielding p-values close to or lower than 0.05 in the univariate analysis, confirmed gender, lower respiratory system infection, and infection with ST147 isolates, but not age or infection with K64 isolates, as risk factors for 30-day mortality. Moreover, the multivariate analysis showed that patients suffering from hematological malignancies or having been treated with inappropriate therapy, both having p-values slightly higher than 0.05 in the univariate analysis, exhibited significantly poorer outcomes in the multivariant analysis. The association of the ST147 clone with an increased risk of mortality is a novel finding that deserves further attention. Studies like the one presented here can certainly benefit the management of patients with nosocomial BSI caused by carbapenemase-producing K. pneumoniae.

Evaluation of a commercial multiplex PCR for diagnosis of central nervous system (CNS) nosocomial infections.

Nosocomial Central Nervous System (CNS) infections are often serious complications of neurosurgical procedures. Their diagnosis is complex and frequently based on microbiological culture. The aim of this work was to evaluate the effectiveness of the FilmArray® Blood Culture Identification (BCID) panel, a multiplex PCR designed to identify the most common etiologic agents of sepsis involved with nosocomial CNS infections. A total of ninety samples were analyzed with the BCID panel. The sensitivity and specificity achieved were 77.4% and 100% respectively, when compared with the reference method (culture). Based on the analysis of the melting curves, another cut-off was established improving sensitivity to 83.9% whilst maintaining 98.3% specificity. The BCID panel seems to be a helpful tool for the prompt diagnosis of CNS nosocomial infections. The cut-off proposed here can increase sensitivity, but further studies are required to confirm its effectiveness and its applicability in clinical microbiology laboratories.

Magnesium poisoning, multi-organ failure and ischemic colitis secondary to chronic ingestion of a parapharmacy product.

The article describes the clinical case of a patient with multi-organ failure and ischemic colitis secondary to magnesium poisoning, due to the chronic intake of a parapharmacy product, used for the treatment of chronic constipation. The clinical case is described and a review of the literature is made.

Age-related injury patterns in Spanish trauma ICU patients. Results from the RETRAUCI.

BACKGROUND: Injury patterns may differ in trauma patients when age is considered. This information is relevant in the management of trauma patients and for planning preventive measures. METHODS: We included in the study all patients admitted for traumatic disease in the participating ICUs from November 23rd, 2012 to July 31st, 2015 with complete records. Data on epidemiology, injury patterns, severity scores, acute management, resources utilisation and outcome were recorded and compared in the following groups of age: ≤55years (young adults), 56-65 years (adults), 66-75 years (elderly), >75years (very elderly). Quantitative data were reported as median (Interquartile Range (IQR) 25-75) and categorical data as number and percentage. Comparison between groups of age with quantitative variables was performed using the analysis of variance (ANOVA) test. Differences between groups with categorical variables were compared using the chi-square test. A value of p<0.05 was considered significant. RESULTS: We included 2700 patients (78.9% male). Median age was 46 (31-62) years. Blunt trauma was present in 93.7% of the patients. Median RTS was 7.55 (5.97-7.84). Median ISS was 20 (13-26). High-energy trauma secondary to motor-vehicle accident with rhabdomyolysis and drugs abuse showed an inverse linear association with ageing, whilst pedestrian falls with isolated brain injury, being run-over and pre-injury antiplatelets or anticoagulant treatment increased with age (in all cases p<0.001). Multiple injuries were more common in young adults (p<0.001). Acute kidney injury prevalence was higher in elderly and very elderly patients (p<0.001). ICU Mortality increased with age in spite of similar severity scores in all groups (p<0.001). The main cause of death in all groups was intracranial hypertension. CONCLUSIONS: Different injury patterns exist in relation with ageing in trauma ICU patients. Adult patients were more likely to present high-energy trauma with significant injuries in different areas whilst elderly patients were prone to low-energy falls, complicated by antiplatelets or anticoagulants use, resulting in severe brain injury and increased mortality.