Elli-Sophia Tripodaki

Lung sonography and recruitment in patients with early acute respiratory distress syndrome: a pilot study.

IntroductionBedside lung sonography is a useful imaging tool to assess lung aeration in critically ill patients. The purpose of this study was to evaluate the role of lung sonography in estimating the nonaerated area changes in the dependent lung regions during a positive end-expiratory pressure (PEEP) trial of patients with early acute respiratory distress syndrome (ARDS).MethodsTen patients (mean ± standard deviation (SD): age 64 ± 7 years, Acute Physiology and Chronic Health Evaluation II (APACHE II) score 21 ± 4) with early ARDS on mechanical ventilation were included in the study. Transthoracic sonography was performed in all patients to depict the nonaerated area in the dependent lung regions at different PEEP settings of 5, 10 and 15 cm H2O. Lung sonographic assessment of the nonaerated lung area and arterial blood gas analysis were performed simultaneously at the end of each period. A control group of five early ARDS patients matched for APACHE II score was also included in the study.ResultsThe nonaerated areas in the dependent lung regions were significantly reduced during PEEP increases from 5 to 10 to 15 cm H2O (27 ± 31 cm2 to 20 ± 24 cm2 to 11 ± 12 cm2, respectively; P < 0.01). These changes were associated with a significant increase in arterial oxygen partial pressure (74 ± 15 mmHg to 90 ± 19 mmHg to 102 ± 26 mmHg; P < 0.001, respectively). No significant changes were observed in the nonaerated areas in the dependent lung regions in the control group.ConclusionsIn this study, we show that transthoracic lung sonography can detect the nonaerated lung area changes during a PEEP trial of patients with early ARDS. Thus, transthoracic lung sonography might be considered as a useful clinical tool in the management of ARDS patients.

The effort-reward imbalance questionnaire in Greek: translation, validation and psychometric properties in health professionals.

The Effort‐reward Imbalance Questionnaire in Greek: Translation, Validation and Psychometric Properties in Health Professionals: Pavlos MSAOUEL, et al. Greek Junior Doctors and Health Scientists Society, Greece—

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.

Assessment of cognitive biases and biostatistics knowledge of medical residents: a multicenter, cross-sectional questionnaire study

Purpose The aim of this study is to determine the perceived familiarity of medical residents with statistical concepts, assess their ability to integrate these concepts in clinical scenarios, and investigate their susceptibility to the gamblers fallacy and the conjunction fallacy. Methods A multi-institutional, cross-sectional survey of Greek medical residents was performed. Participants were asked to indicate their familiarity with basic statistical concepts and answer clinically oriented questions designed to assess their biostatistics knowledge and cognitive biases. Univariate, bivariate, and multivariate statistical models were used for the evaluation of data. Results Out of 153 respondents (76.5% response rate), only two participants (1.3%) were able to answer all seven biostatistics knowledge questions correctly while 29 residents (19%) gave incorrect answers to all questions. The proportion of correct answers to each biostatistics knowledge question ranged from 15 to 51.6%. Residents with greater self-reported familiarity were more likely to perform better on the respective knowledge question (all p<0.01). Multivariate analysis of the effect of individual resident characteristics on questionnaire performance showed that previous education outside Greece, primarily during medical school, was associated with lower biostatistics knowledge scores (p<0.001). A little more than half of the respondents (54.2%) answered the gamblers fallacy quiz correctly. Residents with higher performance on the biostatistics knowledge questions were less prone to the gamblers fallacy (odds ratio 1.38, 95% confidence intervals 1.12–1.70, p=0.003). Only 48 residents (31.4%) did not violate the conjunction rule. Conclusions A large number of medical residents are unable to correctly interpret crucial statistical concepts that are commonly found in the medical literature. They are also especially prone to the gamblers fallacy bias, which may undermine clinical judgment and medical decision making. Formalized systematic teaching of biostatistics during residency will be required to de-bias residents and ensure that they are proficient in understanding and communicating statistical information.Purpose The aim of this study is to determine the perceived familiarity of medical residents with statistical concepts, assess their ability to integrate these concepts in clinical scenarios, and investigate their susceptibility to the gamblers fallacy and the conjunction fallacy. Methods A multi-institutional, cross-sectional survey of Greek medical residents was performed. Participants were asked to indicate their familiarity with basic statistical concepts and answer clinically oriented questions designed to assess their biostatistics knowledge and cognitive biases. Univariate, bivariate, and multivariate statistical models were used for the evaluation of data. Results Out of 153 respondents (76.5% response rate), only two participants (1.3%) were able to answer all seven biostatistics knowledge questions correctly while 29 residents (19%) gave incorrect answers to all questions. The proportion of correct answers to each biostatistics knowledge question ranged from 15 to 51.6%. Residents with greater self-reported familiarity were more likely to perform better on the respective knowledge question (all p<0.01). Multivariate analysis of the effect of individual resident characteristics on questionnaire performance showed that previous education outside Greece, primarily during medical school, was associated with lower biostatistics knowledge scores (p<0.001). A little more than half of the respondents (54.2%) answered the gamblers fallacy quiz correctly. Residents with higher performance on the biostatistics knowledge questions were less prone to the gamblers fallacy (odds ratio 1.38, 95% confidence intervals 1.12-1.70, p=0.003). Only 48 residents (31.4%) did not violate the conjunction rule. Conclusions A large number of medical residents are unable to correctly interpret crucial statistical concepts that are commonly found in the medical literature. They are also especially prone to the gamblers fallacy bias, which may undermine clinical judgment and medical decision making. Formalized systematic teaching of biostatistics during residency will be required to de-bias residents and ensure that they are proficient in understanding and communicating statistical information.

Microcirculatory alterations after cardiopulmonary bypass as assessed with near infrared spectroscopy: a pilot study

To the Editor, Cardiac surgery under cardiopulmonary bypass (CPB) may induce changes in microvascular perfusion and compromise peripheral tissue oxygenation. Near infrared spectroscopy (NIRS) is an easily applicable noninvasive technique that has been used in combination with the vascular occlusion technique (VOT) for the evaluation of the microcirculation. We hypothesized that NIRS and VOT are able to detect the microcirculatory alterations of cardiac surgical patients. After obtaining institutional ethics approval and written informed consent, we conducted a pilot study in nine cardiac surgery patients (three males/ six females). Characteristics of the patients were: age 67 (13), EuroSCORE 6.4 (3.8), left ventricular ejection fraction 58 (9) %, CPB duration 129 (47) min, aortic cross-clamp time 66 (20) min. All patients were anesthetized and their lungs ventilated in a similar manner throughout the monitoring period. The doses of vasopressors/inotropes and propofol did not change during the monitoring period. Near infrared spectroscopy measurements were performed (InSpectra; Hutchinson Technology, Hutchinson, MN, USA) on the day prior to surgery, postoperatively on admission to the intensive care unit, and every two hours for six hours. Tissue oxygen saturation (StO2%) of the thenar eminence was monitored and a brachial VOT was utilized to better assess the microcirculation with the calculation of the oxygen consumption rate and the reperfusion rate. The results of this pilot study are shown in the accompanying Table. Immediately after CPB there were abnormalities in skeletal muscle tissue oxygenation and utilization which normalized at six hours (Table A). Conversely, the global hemodynamic variables did not change significantly in this six-hour monitoring period (Table B). This pilot study indicates that NIRS can detect microvascular derangements whereas routine global measurements seem to be insensitive. Cardiac surgery with CPB induces physiological alterations: the blood is exposed to artificial surfaces, nonpulsatile flow is the norm, the myocardium is arrested with cold cardioplegic protection, and body temperature is lowered by several degrees. These features, in combination with the surgical trauma, contribute to an intense inflammatory reaction resulting in the activation of endothelial cells, leukocytes, platelets, the complement system, and the coagulation cascade. Endothelial dysfunction and the loss of endothelium-dependent vasodilation can lead to the ‘‘noreflow’’ phenomenon and amplify tissue injury. This report shows that NIRS-derived variables depict this local derangement. The improvement of microcirculatory indices during the ensuing hours can be attributed to the restoration of the microcirculation as the hours after surgery progress. Importantly, this report also shows that routine monitors do not reflect these microvasculature abnormalities. Future studies are needed to investigate the possibility of reversing these NIRS-derived microcirculation variables and whether these are important clinical end points. E.-S. Tripodaki, MD A. Tasoulis, MD I. Vasileiadis, MD S. Nanas, MD (&) Evangelismos Hospital, National and Kapodistrian University of Athens, Athens, Greece e-mail: a-icu@med.uoa.gr

Microcirculatory alterations during continuous renal replacement therapy in ICU: A novel view on the 'dialysis trauma' concept.

OBJECTIVE The purpose of this study was to evaluate microcirculation over 24 h renal replacement therapy (CRRT) in critically ill patients. METHODS We conducted a single-center, prospective, observational study, measuring microcirculation parameters, monitored by near infrared spectroscopy (NIRS) before hemodiafiltration onset (H0), and at six (H6) and 24 h (H24) during CRRT in critically ill patients. Serum Cystatin C (sCysC) and soluble (s)E-selectin levels were measured at the same time points. Twenty-eight patients [19 men (68%)] were included in the study. RESULTS Tissue oxygen saturation (StO2, %) [76.5 ± 12.5 (H0) vs 75 ± 11 (H6) vs 70 ± 16 (H24), p = 0.04], reperfusion rate, indicating endothelial function (EF, %/sec) [2.25 ± 1.44 (H0) vs 2.1 ± 1.8 (H6) vs 1.6 ± 1.4 (H24), p = 0.02] and sCysC (mg/L) [2.7 ± 0.8 (H0) vs 2.2 ± 0.6 (H6) vs 1.8 ± 0.8 (H24), p < 0.0001] significantly decreased within the 24 h CRRT. Change of EF positively correlated with changes of sCysC within 24 h CRRT (r = 0.464, p = 0.013) while in patients with diabetes the change of StO2 correlated with dose (r = − 0.8, p = 0.01). No correlation existed between hemoglobin and temperature changes with the deteriorated microcirculation indices. sE-Selectin levels in serum were elevated; no difference was established over the 24 h CRRT period. A strong correlation existed between the sE-Selectin concentration change at H6 and H24 and the mean arterial pressure change in the same period (r = 0.77, p < 0.001). CONCLUSIONS During the first 24 h of CRRT implementation in critically ill patients, deterioration of microcirculation parameters was noted. Microcirculatory alterations correlated with sCysC changes and with dose in patients with diabetes.

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.

Variation of endothelium-related hemostatic factors during sepsis

The thrombomodulin/protein C and VWF/ADAMTS‐13 pathways are disturbed in sepsis and have been implicated in the coagulation disorders that characterize the septic syndrome. We aimed to assess the variation of these endothelial parameters during sepsis and their putative association with outcome, in critically ill, septic patients.

Comparison of Resident Performance in Interpreting Mammography Results Using a Probabilistic or a Natural Frequency Presentation: A Multi‑institutional Randomized Experimental Study

Background: Residents are being increasingly challenged on how best to integrate diagnostic information in making decisions about patient care. The aim of this study is to assess the ability of residents to accurately integrate statistical data from a screening mammography test in order to estimate breast cancer probability and to investigate whether a simple alteration of the representation mode of probabilities into natural frequencies facilitates these computations. Methods: A multi-institutional randomized controlled study of residents was performed in eight major hospitals in the city of Athens. Residents were asked to estimate the positive predictive value of the screening mammography test given its sensitivity and 1-specificity as well as the prevalence of breast cancer in the relevant population. One version of the scenario was presented in the single-event probability format that is commonly used in the medical literature, while the other used the natural frequency representation. The two questionnaire versions were randomly assigned to the participants. Results: Out of 200 residents, 153 completed and returned the questionnaire (response rate 76.5%). Although more than one-third of the residents reported excellent or close to excellent familiarity with sensitivity and positive predictive value, the majority of responses (79.1%) were incorrect. However, a significantly higher proportion of residents in the natural frequency group (n = 88) selected the correct response compared with residents (n = 65) in the single-event probability group (28.4% vs 10.8%; 95% confidence intervals of the difference between the two proportions = 5.6-29.7%; P < 0.01). Discussion: Residents more often correctly understand test performance accuracy when test characteristics are presented to them as natural frequency representations than the more common approach of presenting single event probabilities. Educators and journal editors should be aware of this facilitative effect.