Sleep in Mechanically Ventilated Patients in the Intensive Care Unit

Objective Sleep abnormalities are common in critically ill patients. Polysomnography (PSG) is the gold standard in assessing sleep quality. The aim of this prospective study was to monitor the sleep pattern in mechanically ventilated patients with PSG who were admitted to our medical intensive care unit. Materials and Methods This study was conducted in the Medical Intensive Care Unit of an University Hospital. Patients with endotracheal intubation and mechanical ventilation for at least 24 hours were included in the study. They were monitored for 18 hours per day by continuous PSG. Sleep parameters were recorded; [total sleep time (TST), sleep efficiency (SE) and sleep stages]. Results Records of 12 patients were evaluated. There were nine males and three females. Median age of patients were 72.5 years (min-max=31-92). Median APACHE II was 19 (min-max=10-27). Median sleep time was 489.5 minutes (180-1105), median SE was 77.1% (24.9-96.5) and median arousal number was 147.5/TST (14-450). While REM sleep and non REM stage 3 sleep time and proportion were found to be decreased, non REM stage 2 sleep time and proportion were increased. Conclusion We have shown that mechanically ventilated patients have changes in sleep architecture and that they have severe sleep fragmentation. Future research should address the cause of these problems by using methodology for comprehensive assessment of sleep-disrupting factors and by examining the dynamic effects of changes in illness severity on sleep quality

Drawing: Towards an Intelligence of Seeing

Changes in the microcirculatory parameters in the survivor and non-survivor groups at the following time points: initiation of the VA-ECMO insertion (T1); 48–72 h after VA-ECMO initiation (T2); and 5–6 days after (T3). (DOCX 15 kb

Monitoring microcirculation in critical illness

Purpose of reviewCritical illness includes a wide range of conditions from sepsis to high-risk surgery. All these diseases are characterized by reduced tissue oxygenation. Macrohemodynamic parameters may be corrected by fluids and/or vasoactive compounds; however, the microcirculation and its tissues may be damaged and remain hypoperfused. An evaluation of microcirculation may enable more physiologically based approaches for understanding the pathogenesis, diagnosis, and treatment of critically ill patients.Recent findingsMicrocirculation plays a pivotal role in delivering oxygen to the cells and maintains tissue perfusion. Negative results of several studies, based on conventional hemodynamic resuscitation procedures to achieve organ perfusion and decrease morbidity and mortality following conditions of septic shock and other cardiovascular compromise, have highlighted the need to monitor microcirculation. The loss of hemodynamic coherence between the macrocirculation and microcirculation, wherein improvement of hemodynamic variables of the systemic circulation does not cause a parallel improvement of microcirculatory perfusion and oxygenation of the essential organ systems, may explain why these studies have failed.SummaryCritical illness is usually accompanied by abnormalities in microcirculation and tissue hypoxia. Direct monitoring of sublingual microcirculation using hand-held microscopy may provide a more physiological approach. Evaluating the coherence between macrocirculation and microcirculation in response to therapy seems to be essential in evaluating the efficacy of therapeutic intervention

The response of the microcirculation to cardiac surgery

Purpose of reviewCardiac surgery is associated with a wide range of microvascular derangements and with reduced tissue oxygenation. Although the macrohemodynamical targets during surgery may be achieved, the microcirculation may be damaged and remain dysfunctional. Direct observations of the microcirculation may enable more physiologically based approaches for diagnosis and treatment during cardiac surgery.Recent findingsMicrocirculation is the final destination of blood flow to the tissues for oxygen transport. Direct visualization of the microcirculation using hand-held microscopy can be considered the gold standard for tissue perfusion since the movement of single red blood cells can be observed and quantified. A new generation microcirculation-monitoring device is called CytoCam-Incident -Dark-Field imaging. This device has a high-resolution imaging sensor and shows approximately 30% more capillaries than the devices of the previous generations. On-pump and off-pump cardiac surgeries have induced different mechanism whose impact can be differentiated by observation of the sublingual microcirculation. Colloids may provide a better volume expansion and microcirculatory improvement than crystalloids although crytaloids may be more affective for hydration, and blood transfusions improves microcirculatory oxygenation by filling previously empty capillaries and reducing diffusion distances between oxygen carrying red blood cell and the parenchymal cells.SummaryDirect visualization of the microcirculation using hand-held microscopy may provide the clinician the physiological feedback that is required for the early diagnosis and treatment of microcirculatory alterations during cardiac surgery. The coherence between the hemodynamic response of the macrocirculation and microcirculation during surgery seems to be essentia

Monitoring microcirculation

The clinical relevance of microcirculation and its bedside observation started gaining importance in the 1990s since the introduction of hand-held video microscopes. From then, this technology has been continuously developed, and its clinical relevance has been established in more than 400 studies. In this paper, we review the different types of video microscopes, their application techniques, the microcirculation of different organ systems, the analysis methods, and the software and scoring systems. The main focus of this review will be on the state-of-art technique, CytoCam-incident dark-field imaging, and the most recent technological and technical updates concerning microcirculation monitoring. (C) 2016 Elsevier Ltd. All rights reserve

The response of the microcirculation to mechanical support of the heart in critical illness

Critical illness associated with cardiac pump failure results in reduced tissue perfusion in all organs and occurs in various conditions such as sepsis, cardiogenic shock, and heart failure. Mechanical circulatory support (MCS) devices can be used to maintain organ perfusion in patients with cardiogenic shock and decompensated chronic heart failure. However, correction of global hemodynamic parameters by MCS does not always cause a parallel improvement in microcirculatory perfusion and oxygenation of the organ systems, a condition referred to as a loss of hemodynamic coherence between macro-and microcirculation (MC). In this paper, we review the literature describing hemodynamic coherence or loss occurring during MCS of the heart. By using Embase, Medline Cochrane, Web of Science, and Google Scholar, we analyzed the literature on the response of MC and macrocirculation to MCS of the heart in critical illness. The characteristics of patients, MCS devices, and micro-and macrocirculatory parameters were very heterogenic. Short-term MCS studies (78%) described the effects of intra-aortic balloon pumps (IABPs) on the MC and macrocirculation. Improvement in MC, observed by handheld microscopy (orthogonal polarization spectral (OPS), sidestream dark-field (SDF), and Cytocam IDF imaging) in line with restored macrocirculation was found in 44% and 40% of the studies of short-and long-term MCS, respectively. In only 6 of 14 studies, hemodynamic coherence was described. It is concluded that more studies using direct visualization of the MC in short-and long-term MCS by handheld microscopy are needed, preferably randomized controlled studies, to identify the presence and clinical significance of hemodynamic coherence. It is anticipated that these further studies can enable to better identify patients who will benefit from treatment by mechanical heart support to ensure adequate organ perfusion. (C) 2016 Elsevier Ltd. All rights reserve

Raman and AFM studies on nominally undoped, p- and n-type GaAsBi alloys

We study structural properties and surface formation of undoped, n- and p-type doped GaAsBi alloys with various bismuth compositions using Micro-Raman, Fourier Transform (FT) Raman, Photoluminescence (PL) and Atomic Force Microscopy (AFM) techniques. PL is used to determine the suitable excitation source for Raman measurements and evaluate the Raman spectroscopy results. Room temperature PL results reveal that the bandgap energy of GaAsBi decreases with increasing bismuth composition at a rate of 82meV/%Bi. In micro-Raman spectra recorded using 532 nm laser line, a peak at around 185 cm(-1) and a broad peak located between 210 and 250 cm(-1) are observed. The absence of these peaks in the Raman spectrum of low temperature (LT) growth GaAs indicates that those peaks are bismuth-induced vibrations. Besides, the forbidden transverse optical (TO) mode (269 cm(-1)) becomes more pronounced for the samples as bismuth composition increases. FT-Raman spectra taken by 1064 nm laser line of the n- and p-type samples exhibit different characteristics; while TO and longitudinal optical (LO) peaks (291 cm(-1)) are present in n-type sample as sharp vibrational peaks, a broad peak located at slightly lower wavenumber than TO mode appears and LO peak is suppressed. The ionised acceptor and free hole system respond incident electromagnetic field as plasma oscillations. Moreover, the amplitude of the plasma oscillations enhances with higher doping density. Therefore, the appearance of the broad peak in FT-Raman spectrum of p-type GaAsBi is explained with an LO-plasmon coupling (LOPC). As for n-type samples, free electrons are compensated by free holes in GaAsBi that originate from Bi-induced acceptor-like defects. Therefore, we do not observe the effects of plasma oscillations in FT-Raman spectrum. AFM results reveal that all samples have surface droplets, and the size of the droplets is not affected from doping density or doping type, but bismuth composition. The surface droplets are removed by a chemical process to investigate the effect of the droplets on Raman spectrum. Our results reveal that removing surface droplets does not change the characteristic of Raman spectrum, but enhances the Raman intensity due to the reflected light by droplets decreases, leading to more photons penetrate and scattered from inside the sample. (C) 2017 Elsevier B.V. All rights reserved

Acute Tuberculosis In The Intensive Care Unit

Background/aim: The aim of this study was to determine mortality rates and to evaluate clinical features of patients with active tuberculosis (TB) requiring intensive care unit (ICU) admission. Materials and methods: The medical records of active TB patients requiring ICU admission were retrospectively reviewed over a 5-year period. Results: Sixteen patients with active TB admitted to the ICU were included in the study. Seven (43.8%) patients died in the ICU. The cause of mortality was septic shock in 5 patients and respiratory failure in 2 patients. The Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores were higher in patients who died (P - 0.012 and 0.048, respectively). Six of the 8 immunosuppressed patients and 1 of the 8 nonimmunosuppressed patients died (P = 0.041). The median mechanical ventilation (MV) duration was longer in patients who died (11 (5-45) days) than in patients who survived (4.5 (3-7) days) (P = 0.036). Seven of the 8 patients with nosocomial infection and/or coinfection died, while all of the patients without additional infection survived (P = 0.01). Conclusion: Active TB patients admitted to the ICU had higher mortality rates, especially patients with immunosuppression, nosocomial infection, high APACHE II and SOFA scores, and patients receiving MV.WoSScopu