Theodoros Kyprianou

Circulating endothelial and progenitor cells: Evidence from acute and long-term exercise effects

Circulating bone-marrow-derived cells, named endothelial progenitor cells (EPCs), are capable of maintaining, generating, and replacing terminally differentiated cells within their own specific tissue as a consequence of physiological cell turnover or tissue damage due to injury. Endothelium maintenance and restoration of normal endothelial cell function is guaranteed by a complex physiological procedure in which EPCs play a significant role. Decreased number of peripheral blood EPCs has been associated with endothelial dysfunction and high cardiovascular risk. In this review, we initially report current knowledge with regard to the role of EPCs in healthy subjects and the clinical value of EPCs in different disease populations such as arterial hypertension, obstructive sleep-apnea syndrome, obesity, diabetes mellitus, peripheral arterial disease, coronary artery disease, pulmonary hypertension, and heart failure. Recent studies have introduced the novel concept that physical activity, either performed as a single exercise session or performed as part of an exercise training program, results in a significant increase of circulating EPCs. In the second part of this review we provide preliminary evidence from recent studies investigating the effects of acute and long-term exercise in healthy subjects and athletes as well as in disease populations.

The Diagnostic Value of Gram Stain of Bronchoalveolar Lavage Samples in Patients with Suspected Ventilator-associated Pneumonia

Ventilator-associated pneumonia (VAP) is one of the most common causes of morbidity and mortality in intensive care unit patients. However, the diagnosis is quite difficult. Gram stain (GS) of bronchoalveolar lavage (BAL) sample is a time-saving diagnostic method for VAP. However, its clinical significance has not been adequately investigated. The aim of this study was to determine its sensitivity and specificity for VAP diagnosis. We prospectively performed GS and quantitative bacterial cultures (QBC) of BAL samples, obtained through fiberoptic bronchoscope, in 75 consecutive postoperative and/or multiple trauma patients with suspected VAP. We considered BAL-GS as positive for VAP diagnosis when (i) polymorphonuclear neutrophils were > 25 per optic field at a magnification x 100 (p.o.f x 100); (ii) squamous epithelial cells were < 1% p.o.f x 100; and (iii) one or more microorganisms were seen p.o.f. at a magnification x 1,000 (p.o.f. x 1,000). VAP was diagnosed with criteria similar to those used in previous studies. Pneumonia was the final diagnosis in 22/75 (29%) patients. The BAL-GS was positive in 17/22 patients with VAP and in 7/53 patients without VAP. Accordingly, the sensitivity of BAL-GS for VAP diagnosis was 77%, the specificity 87%, the positive predictive value 71% and the negative predictive value 90%. Our data suggest that BAL-GS has good sensitivity and high specificity for VAP diagnosis. It could therefore constitute a useful complementary tool in the task of early diagnosis and treatment of VAP.

Effects of interval exercise training on respiratory drive in patients with chronic heart failure

BACKGROUND Patients with chronic heart failure (CHF) suffer from ventilatory abnormalities. This study examined the effects of interval exercise training on the respiratory drive in CHF patients. METHODS Forty-six clinically stable CHF patients (38 males/8 women, mean age = 53 +/- 11 years) participated in an exercise rehabilitation program (ERP) 3 times/week, for 12 weeks by interval training modality with or without the addition of resistance training. All patients underwent symptom-limited cardiopulmonary exercise testing (CPET), and measurements of mouth occlusion pressure at 100 ms (P(0.1)) and maximum inspiratory muscle strength (P(Imax)) before and after ERP. Respiratory drive was estimated by mouth occlusion pressure P(0.1) and P(0.1)/P(Imax) ratio at rest, and the ventilatory pattern by resting mean inspiratory flow (V(T)/T(I)) and by V(T)/T(I) at identical CPET workloads, before and after ERP. We also studied a control non exercising group of 11 patients (8 men and 3 women). RESULTS P(0.1) at rest decreased from 3.04 +/- 1.52 to 2.62 +/- 0.9 cmH(2)O (p = 0.015), P(0.1)/P(Imax) % at rest from 4.56 +/- 3.73 to 3.69 +/- 2.03 (p = 0.006), resting V(T)/T(I) from 0.44 +/- 0.10 to 0.41 +/- 0.10 l/s (p = 0.014), and V(T)/T(I) at identical work rate from 2.13 +/- 0.59 to 1.93 +/- 0.58 l/s (p = 0.001) after ERP. VO(2) at peak exercise increased from 16.3 +/- 4.8 to 18.5 +/- 5.3 ml/kg/min (p < 0.001) in the exercise group. No improvement was noted in the control group. CONCLUSIONS ERP by interval training improves the respiratory drive and ventilatory pattern at rest and during exercise in CHF patients.

Intensive Care Window: Real-Time Monitoring and Analysis in the Intensive Care Environment

This paper introduces a novel, open-source middleware framework for communication with medical devices and an application using the middleware named intensive care window (ICW). The middleware enables communication with intensive care unit bedside-installed medical devices over standard and proprietary communication protocol stacks. The ICW application facilitates the acquisition of vital signs and physiological parameters exported from patient-attached medical devices and sensors. Moreover, ICW provides runtime and post-analysis procedures for data annotation, data visualization, data query, and analysis. The ICW application can be deployed as a stand-alone solution or in conjunction with existing clinical information systems providing a holistic solution to inpatient medical condition monitoring, early diagnosis, and prognosis.

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.

Novel Biomarkers of Acute Kidney Injury in the General Adult ICU: A Review

Acute kidney injury is one of the most frequent problems occurring in the critically ill patients of the intensive care units and it is well established that it increases both morbidity and mortality in these patients. Moreover, despite technological and pharmaceutical advances during the last decades, the incidence as well as the mortality associated with acute kidney injury in these patients remains unchanged. Creatinine, the most common renal dysfunction biomarker in use, has many disadvantages, such as time delay in its increase and the influence by other factors on its serum concentration, such as age, gender, muscle mass, etc. Hence, the need for better renal biomarkers in order to timely intervene for acute kidney injury prevention is imperative. The lack of an early biomarker is an obstacle for the development of new acute kidney injury prevention strategies. With the incidence of acute kidney injury reaching epidemic dimensions, the need for novel markers is urgent. During the last years, the research for finding such biomarkers has been intense. The purpose of the present article is to review the studies which have tested the predictive ability of those markers (in urine and/or plasma) for early detection of acute kidney injury in the mixed adult intensive care unit population and underline the potential limitations encountered in the various studies.

Attitudes towards euthanasia among Greek intensive care unit physicians and nurses

OBJECTIVES To investigate the attitudes of Greek intensive care unit (ICU) medical and nursing staff towards euthanasia. BACKGROUND ICU physicians and nurses deal with end-of-life dilemmas on a daily basis. Therefore, the exploration of their stances on euthanasia is worthwhile. METHODS This was a descriptive quantitative study conducted in three ICUs in Athens. The convenience sample included 39 physicians and 107 nurses. RESULTS Of respondents, 52% defined euthanasia inaccurately, as withholding or withdrawal of treatment, while 15% ranked limitation of life-support among the several forms of euthanasia, together with active shortening of the dying process and physician - assisted suicide. Only one third of participants defined euthanasia correctly. While 59% of doctors and 64% of nurses support the legalization of active euthanasia, just 28% and 26% of them, respectively, agree with it ethically. CONCLUSIONS Confusion prevails among Greek ICU physicians and nurses regarding the definition of euthanasia. The majority of staff disagrees with active euthanasia, but upholds its legalization.

Data-centric privacy protocol for intensive care grids

Modern e-Health systems require advanced computing and storage capabilities, leading to the adoption of technologies like the grid and giving birth to novel health grid systems. In particular, intensive care medicine uses this paradigm when facing a high flow of data coming from intensive care units (ICU) inpatients just like demonstrated by the ICGrid system prototyped by the University of Cyprus. Unfortunately, moving an ICU patients data from the traditionally isolated hospitals computing facilities to data grids via public networks (i.e., the Internet) makes it imperative to establish an integral and standardized security solution to avoid common attacks on the data and metadata being managed. Particular emphasis must be put on the patients personal data, the protection of which is required by legislations in many countries of the European Union and the world in general. In this paper, we extend our previous research with the following contributions: 1) a mandatory access control model to protect patients metadata; 2) a major security revision to our previously proposed privacy protocol by contributing with a “quality of security” quantitative metric to improve fragmented datas assurance; and finally, 3) a set of early results to demonstrate that our protocol not only improves a patient personal datas security and privacy but also achieves a performance comparable with existing approaches.

Development of a new bed system with improved decubitus prophylaxis for bed-ridden patients

An adaptable bedding surface for the prophylaxis and treatment of decubitus ulcers was developed and evaluated in a number of preclinical studies. The new bed reduced the average contact pressure peaks in prolonged supine bed rest while significantly decelerating the onset and progression of pressure sores. A special advantage of the surface is its discrete, independently-mobile pin elements that allow localized implementation of sensors and diagnostic tools in the bed structure. The bed is currently being evaluated in clinical trials with at series of different patient populations with different pressure ulcer pathologies. The systems overall ability to prevent the conditions that contribute to the onset of ulcers as indicated by improvements on the ulcer incidence rate is presented here.

Intensive Care Window: A Multi-Modal Monitoring Tool for Intensive Care Research and Practice

Intensive Care Units are widely considered as the most technologically advanced environments within a hospital. In such environments, physicians are confronted with multiple medical devices that monitor the inpatients. The capability to collect, store, process, and share inpatient monitoring data along with the remarks of the treating physicians can bring tremendous benefits to all aspects of Intensive Care Medicine (practice, research, education). The IC-Window makes it feasible for physicians to extract, view, store, and replay Clinically Interesting Episodes through simple, intuitive user interfaces.