Maria Parisi

Combination of Renal Biomarkers Predicts Acute Kidney Injury in Critically Ill Adults

Objective: Most studies so far have focused on the performance of individual biomarkers to detect early acute kidney injury (AKI) in the adult intensive care unit (ICU) patients; however, they have not determined the predictive ability of their combinations. The aim of this study was to compare the predictive abilities of plasma neutrophil gelatinase-associated lipocalin (pNGAL), urine neutrophil gelatinase-associated lipocalin (uNGAL), plasma cystatin C (pCysC), serum creatinine (sCr), and their combinations in detecting AKI in an adult general ICU population. Methods: A total of 100 consecutive ICU patients were included in the analysis. AKI was defined according to RIFLE criteria. Biomarker predictive abilities were evaluated by area under the curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Results: AKI occurred in 36% of patients 7 days post-admission. All three novel biomarkers as well as sCr had moderate predictive abilities for AKI occurrence. The most efficient combinations (pNGAL + sCr and pNGAL + uNGAL + sCr) were selected to participate in the subsequent analyses. Both combinations, when added to a reference clinical model, increased its AUC significantly (0.858, p = 0.04). Their NRI (0.78, p = 0.0002) was equal to that of pNGAL, but higher than that of the other three biomarkers, whereas their IDI was higher than that of any individual biomarker (0.23, p = 0.0001). Both combinations had better specificities, positive likelihood ratios, and positive predictive values than those of any individual biomarker. Conclusion: The biomarker combinations had better predictive characteristics compared with those of each biomarker alone.

Prediction of the renal replacement therapy requirement in mechanically ventilated critically ill patients by combining biomarkers for glomerular filtration and tubular damage

PURPOSE Mechanically ventilated critically ill patients with high severity score indices need a very cautious therapeutic approach. Considering that inappropriate decisions on renal replacement therapy (RRT) initiation may promote unwanted adverse effects, we evaluated whether a panel of novel and traditional renal markers is superior to conventional renal marker in predicting RRT requirements in this group of patients. METHODS This was a prospective observational study, performed at the two distinct multidisciplinary intensive care units (ICUs) of a 1000-bed tertiary hospital. Of 310 consecutive patients, 106 patients fulfilled the inclusion criteria of the study. Urinary neutrophil gelatinase-associated lipocalin (uNGAL), serum creatinine (sCr) and serum cystatin C (sCysC) were determined on ICU admission. The predictive performance of all markers for first RRT was tested and compared based on the area under the receiver operating characteristic (ROC) curves. Time-dependent ROC curves were used to assess the earlier time point where the markers presented their maximum area under the curve (AUC). RESULTS All studied biomarkers and acute physiology and chronic health evaluation (APACHE) II score, were significant independent predictors of RRT (uNGAL-AUC=0.73, sCysC-AUC=0.76, sCr-AUC=0.78, APACHE-AUC=0.73, P<0.0001). sCysC and sCr showed early maximum predictive ability within 10 days of ICU admission, while uNGAL and APACHE II score within 11 days of ICU admission. sCr combined with normalized (n)NGAL and sCysC combined with either nNGAL or uNGAL established best predictors for the RRT initiation (AUC-ROC=0.8). Distinguishing patients without acute kidney injury (AKI) on ICU entry, the combination of sCysC and APACHE II score proved best (AUC-ROC=0.78). CONCLUSIONS Specific markers of kidney dysfunction and of kidney damage can be successfully combined to increase the prognostic capability for RRT initiation. The presence of AKI affects diagnostic performance. Without an established AKI on ICU admission, future RRT requirement was better predicted by the combination of illness severity with a marker of glomerular filtration rate. With AKI on ICU admission a combination of the marker of glomerular filtration rate with one of tubular injury proved best.

Risk factors for tracheobronchial acquisition of resistant Gram-negative bacterial pathogens in mechanically ventilated ICU patients.

Abstract The aim of this study was to identify risk factors for tracheobronchial acquisition with the most common resistant Gram-negative bacteria in the intensive care unit (ICU) during the first week after intubation and mechanical ventilation. Tracheobronchial and oropharyngeal cultures were obtained at admission, after 48 hours, and after 7 days of mechanical ventilation. Patient characteristics, interventions, and antibiotic usage were recorded. Among 71 eligible patients with two negative bronchial cultures for resistant Gram-negative bacteria (at admission and within 48 hours), 41 (58%) acquired bronchial resistant Gram-negative bacteria by day 7. Acquisition strongly correlated with presence of the same pathogens in the oropharynx: Acinetobacter baumannii [odds ratio (OR) = 20·2, 95% confidence interval (CI): 5·5–73·6], Klebsiella pneumoniae (OR = 8·0, 95% CI: 1·9–33·6), and Pseudomonas aeruginosa (OR = 27, 95%: CI 2·7–273). Bronchial acquisition with resistant K. pneumoniae also was associated with chronic liver disease (OR = 3·9, 95% CI: 1·0–15·3), treatment with aminoglycosides (OR = 4·9, 95% CI: 1·4–18·2), tigecycline (OR = 4·9, 95% CI: 1·4–18·2), and linezolid (OR = 3·9, 95% CI: 1·1–15·0). In multivariate analysis, treatment with tigecycline and chronic liver disease were independently associated with bronchial resistant K. pneumoniae acquisition. Our results show a high incidence of tracheobronchial acquisition with resistant Gram-negative microorganisms in the bronchial tree of newly intubated patients. Oropharynx colonization with the same pathogens and specific antibiotics use were independent risk factors.

Changes in skeletal muscle microcirculation after a hemodialysis session correlates with adequacy of dialysis.

Background Monitoring of the microcirculation may add additional information in terms of improving the adequacy of hemodialysis (HD) for patients. Withdrawal of liquid and complement activation during a HD session reduces the external pressure on the microcirculation and leads to an increased dilatation of the peripheral capillaries. The purposes of this study were to assess the effect of a single HD or hemodiafiltration session on the thenar microcirculation in patients with end-stage renal disease (ESRD) with or without diabetes, investigate the possible relationship between changes in the microcirculation and adequacy of dialysis (including Kt/V and parameters indicating secondary hyperparathyroidism), and compare microcirculation measurements obtained from patients with ESRD and those from healthy controls. Methods This pilot prospective observational study including eleven patients with ESRD on maintenance HD (nine men of mean age 73±10.5 years, ten [91%] with hypertension), nine patients with ESRD on maintenance hemodiafiltration (six men of mean age 65.5±13.2 years, five [55.5%] with diabetes and four [44.5%] with hypertension), and eight healthy volunteers. Two paired microcirculation assessments were recorded for each HD patient before and after a dialysis session. Near infrared spectroscopy and the vascular occlusion test were used to assess the microcirculation, and blood work samples were collected before and after dialysis when the pump slowed down. Results Patients with ESRD showed an increase in thenar cell metabolism at rest after a 4-hour HD session, and changes in cell metabolism correlated with the Kt/V of the session. Pre-dialysis tissue oxygen saturation over the 4-hour HD session correlated with pre-dialysis serum calcium and parathyroid hormones. Vascular reactivity was lower in ESRD patients receiving HD or hemodiafiltration than in healthy controls. Conclusion Improvement in skeletal muscle microcirculation noted after a HD session was related to adequacy of dialysis. Evaluation of the microcirculation may provide additional information for management of patients on HD and identify novel targets for treatment. These preliminary findings need to be tested using a larger data set.

LB026-MON: Type of Feeding and Risk of Bloodstream Infections in Critically Ill Patients

LB025-MON GLUTAMINE MAY ALTER THE WEAK LPS BUT NOT THE STRONG HEAT SHOCK INTRACELLULAR HSP72 INDUCTION IN CRITICALLY ILL PATIENTS E. Briassouli1, M. Tzanoudaki2, G. Daikos1, K. Vardas3, M. Kanariou2, C. Routsi3, S. Nanas3, G. Briassoulis4. 11st Department of Propaedeutic Internal Medicine, University of Athens, 2Department of Immunology Histocompatibility, Specialized Center & Referral Center for Primary Immunodeficiencies Paediatric Immunology, “Aghia Sophia” Children’s Hospital, 3First Critical Care Department, University of Athens, Athens, 4PICU, University of Crete/University Hospital, Heraklion, Crete, Greece