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Purpose To access the effect of propofol administration on sleep quality in critically ill patients ventilated on assisted modes. Methods This was a randomized crossover physiological study conducted in an adult ICU at a tertiary hospital. Two nights' polysomnography was performed in mechanically ventilated critically ill patients with and without propofol infusion, while respiratory variables were continuously recorded. Arterial blood gasses were measured in the beginning and at the end of the study. The rate of propofol infusion was adjusted to maintain a sedation level of 3 on the Ramsay scale. Sleep architecture was analyzed manually using predetermined criteria. Patient-ventilator asynchrony was evaluated breath by breath using the flow-time and airway pressure-time waveforms. Results Twelve patients were studied. Respiratory variables, patient-ventilator asynchrony, and arterial blood gasses did not differ between experimental conditions. With or without propofol all patients demonstrated abnormal sleep architecture, expressed by lack of sequential progression through sleep stages and their abnormal distribution. Sleep efficiency, sleep fragmentation, and sleep stage distribution (1, 2, and slow wave) did not differ with or without propofol. Compared to without propofol, both the number of patients exhibiting REM sleep (p = 0.02) and the percentage of REM sleep (p = 0.04) decreased significantly with propofol. Conclusions In critically ill patients ventilated on assisted modes, propofol administration to achieve the recommended level of sedation suppresses the REM sleep stage and further worsens the poor sleep quality of these patients., Author(s): Eumorfia Kondili [sup.1], Christina Alexopoulou [sup.1], Nectaria Xirouchaki [sup.1], Dimitris Georgopoulos [sup.1] Author Affiliations: (1) grid.8127.c, 0000000405763437, Intensive Care Medicine Department, University Hospital of Heraklion, School of Medicine, University [...]

Background Recently, a new technology has been introduced aiming to monitor and improve patient ventilator interaction (PVI monitor). With the PVI monitor, a signal representing an estimation of the patient's total inspiratory muscle pressure (Pmus.sub.PVI) is calculated from the equation of motion, utilizing estimated values of resistance and elastance of the respiratory system. Objective The aim of the study was to prospectively examine the accuracy of Pmus.sub.PVI to quantify inspiratory muscle pressure. Methods and interventions Eleven critically ill patients mechanically ventilated on proportional assist ventilation with load-adjustable gain factors were studied at three levels of assist (30, 50 and 70%). Airway, esophageal, gastric and transdiaphragmatic (Pdi) pressures, volume and flow were measured breath by breath, whereas the total inspiratory muscle pressure (Pmus) was calculated using the Campbell diagram. Results For a given assist, Pmus.sub.PVI throughout inspiration did not differ from the corresponding values calculated using the Pdi and Pmus signals. Inspiratory and expiratory time did not differ among the various methods of calculation. Inspiratory muscle pressure decreased with increasing assist, and the magnitude of this decrease did not differ among the various methods of pressure calculation. Conclusions A signal generated from flow, volume and airway pressure may be used to provide breath-by-breath quantitative information of inspiratory muscle pressure., Author(s): Eumorfia Kondili [sup.1] , Christina Alexopoulou [sup.1] , Nectaria Xirouchaki [sup.1] , Katerina Vaporidi [sup.1] , Dimitris Georgopoulos [sup.1] Author Affiliations: (1) Intensive Care Medicine Department, University Hospital of [...]

Byline: Nectaria Xirouchaki (1), Eumorfia Kondili (1), Maria Klimathianaki (1), Dimitris Georgopoulos (1) Keywords: Ventilator settings; Sedatives; Analgesics; Vasoactive medications; Critically ill Abstract: Objectives The aim of this study was to compare the number of interventions (ventilator settings and sedatives, analgesics and vasoactive medication dose manipulations) between critically ill patients on proportional-assist ventilation with load-adjustable gain factors (PAV+) and those on pressure support (PS). Design Retrospective analysis of data from a previous randomized clinical trial. Methods A total of 208 patients who were mechanically ventilated on controlled modes and met criteria for assisted breathing were randomized to receive either PS (n = 100) or PAV+ (n = 108). Changes in ventilator settings and in the dose of sedatives, analgesics, and vasoactive medications were identified during the period in which the patients were ventilated either with PS (30.4 +- 17.4 h) or PAV+ (30.0 +- 18.1 h) and classified as changes to facilitate weaning (CFW) or changes to respond to deterioration (CD). Results The mean number of changes in ventilator settings was significantly higher with PS than that with PAV+ (10.7 +- 5.7 vs. 8.9 +- 4.6). With PS the proportion of these changes classified as CFW was significantly lower than that with PAV+ (59.8% vs. 69.2%). Dyssynchrony as a cause of CD was more likely to occur with PS than with PAV+ (42 vs. 3%). The mean number of changes in the dose of sedatives, analgesics, and vasoactive medications was higher with PS than with PAV+, the difference being significant only for sedatives (4.06 +- 3.8 vs. 2.82 +- 3.4). Conclusions Compared to PS, PAV+ is associated with fewer intervention in terms of ventilator settings and sedative dose changes. Author Affiliation: (1) Department of Intensive Care Medicine, University Hospital of Heraklion, Medical School, University of Crete, Heraklion, Crete, Greece Article History: Registration Date: 28/05/2009 Received Date: 19/03/2009 Accepted Date: 20/05/2009 Online Date: 16/06/2009 Article note: Electronic supplementary material The online version of this article (doi: 10.1007/s00134-009-1524-2) contains supplementary material, which is available to authorized users.

Byline: Eumorfia Kondili (1), Christina Alexopoulou (1), George Prinianakis (1), Nectaria Xirouchaki (1), Dimitris Georgopoulos (1) Keywords: Resistance; Flow limitation; Compliance; Time constant Abstract: Objectives To study the pattern of lung emptying and expiratory resistance in mechanically ventilated patients with chronic obstructive pulmonary disease (COPD). Design A prospective physiological study. Setting A 12-bed Intensive Care Unit. Patients Ten patients with acute exacerbation of COPD. Interventions At three levels of positive end-expiratory pressure (PEEP, 0, 5 and 10 cm[H.sub.2]O) tracheal (Ptr) and airway pressures, flow (V') and volume (V) were continuously recorded during volume control ventilation and airway occlusions at different time of expiration. Measurements and results V-V' curves during passive expiration were obtained, expired volume was divided into five equal volume slices and the time constant (I) and dynamic deflation compliance (Crs.sub.dyn) of each slice was calculated by regression analysis of V-V' and post-occlusion V-Ptr relationships, respectively. In each volume slice the existence or not of flow limitation was examined by comparing V-V' curves with and without decreasing Ptr. For a given slice total expiratory resistance was calculated as I/Crs.sub.dyn, whereas expiratory resistance (Rrs) and time constant (I.sub.rs) of the respiratory system were subsequently estimated taken into consideration the presence of flow limitation. At zero PEEP, I.sub.rs increased significantly toward the end of expiration due to an increase in Rrs. PEEP significantly decreased Rrs at the end of expiration and resulted in a faster and relatively constant rate of lung emptying. Conclusions Patients with COPD exhibit a decrease in the rate of lung emptying toward the end of expiration due to an increase in Rrs. PEEP decreases Rrs, resulting in a faster and uniform rate of lung emptying. Author Affiliation: (1) Department of Intensive Care Medicine, University Hospital of Heraklion, University of Crete, 711 10, Heraklion, Crete, Greece Article History: Registration Date: 27/02/2004 Received Date: 10/09/2003 Accepted Date: 17/02/2004 Online Date: 31/03/2004 Article note: Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00134-004-2255-z An erratum to this article can be found at http://dx.doi.org/10.1007/s00134-004-2435-x

Author(s): Dimitris Georgopoulos [sup.1], Nectaria Xirouchaki [sup.1], Giovanni Volpicelli [sup.2] Author Affiliations: (1) grid.8127.c, 0000000405763437, Department of Intensive Care Medicine, University Hospital of Heraklion, Medical School, University of Crete, , [...]

Byline: Eumorfia Kondili (1), Christina Alexopoulou (1), George Prinianakis (1), Nectaria Xirouchaki (1), Dimitris Georgopoulos (1) Author Affiliation: (1) Department of Intensive Care Medicine, University Hospital of Heraklion, University of Crete, 711 10, Heraklion, Crete, Greece Article History: Registration Date: 11/08/2004 Online Date: 17/08/2004 Article note: The online version of the original article can be found at http://dx.doi.org/10.1007/s00134-004-2255-z