Papers by Raffaele Dellacà
Clinical & Experimental Allergy, Mar 18, 2019
Background. An increased day-by-day variability of airway obstruction is a characteristic feature... more Background. An increased day-by-day variability of airway obstruction is a characteristic feature of Asthma. It is currently assessed by PEF over 2 weeks, but its value as a diagnostic tool remains questionable. Aim. To evaluate whether the variability of inspiratory resistance (Rinsp) measured by the Forced Oscillation Technique (FOT) and expressed as its standard deviation (SDRinsp) could reliably identify patients with Asthma. Methods. 40 mild Asthmatics (PD20 Results. The AUC of SDRinsp grew with the number of FOT tests, reaching a plateau (95% CI) at 0.97 (0.95 – 0.99) when calculated on periods of 14 days. Further addition of data points did not increase it significantly (p>0.23). Results were confirmed when using the FOT data of the other 60 participants (p>0.05) while PEF variability provided an AUC=0.63 (0.47 – 0.79) lower than FOT (p Conclusions. Increased SDRinsp is specific for Asthma and persists with time. Compared with PEF, it improved sensitivity and specificity, providing an objective and accurate test for the diagnosis of Asthma.
<b>Copyright information:</b>Taken from "Chest wall mechanics during pressure su... more <b>Copyright information:</b>Taken from "Chest wall mechanics during pressure support ventilation"Critical Care 2006;10(2):R54-R54.Published online 31 Mar 2006PMCID:PMC1550890. Mean ± standard error of the mean (SEM) values of transdiaphragmatic pressure (Pdi; closed symbols) and rib cage muscle pressure (Prcm; open symbols) at different levels of pressure support. **&lt; 0.01,***&lt; 0.001, versus pressure support at 5 cmHO. °&lt; 0.01, versus pressure support at 10 cmHO. &lt; 0.05, versus Prcm. Mean ± SEM values of percentage contribution to tidal volume of abdomen (Vab; closed symbols) and rib cage (Vrc; open symbols) at different levels of pressure support. *&lt; 0.05, versus Pressure support at 5 cmHO. Mean ± SEM values of absolute values of phase shift between rib cage (RC) and abdomen (AB) at different levels of pressure support. **&lt; 0.01, versus pressure support at 25 cmHO. °°&lt; 0.01 versus pressure support at 15 cmHO.
This is an open access article distributed under the terms of the Creative Commons Attribution Li... more This is an open access article distributed under the terms of the Creative Commons Attribution License
Respiratory Research, 2021
Delivery of medications to preterm neonates receiving non-invasive ventilation (NIV) represents o... more Delivery of medications to preterm neonates receiving non-invasive ventilation (NIV) represents one of the most challenging scenarios for aerosol medicine. This challenge is highlighted by the undersized anatomy and the complex (patho)physiological characteristics of the lungs in such infants. Key physiological restraints include low lung volumes, low compliance, and irregular respiratory rates, which significantly reduce lung deposition. Such factors are inherent to premature birth and thus can be regarded to as the intrinsic factors that affect lung deposition. However, there are a number of extrinsic factors that also impact lung deposition: such factors include the choice of aerosol generator and its configuration within the ventilation circuit, the drug formulation, the aerosol particle size distribution, the choice of NIV type, and the patient interface between the delivery system and the patient. Together, these extrinsic factors provide an opportunity to optimize the lung de...
European Respiratory Journal, Sep 1, 2013
B65. SLEEP-DISORDERED BREATHING: MANAGEMENT AND OUTCOMES, 2009
2009 International Conference on eHealth, Telemedicine, and Social Medicine, 2009
The dissemination of the available telemedicine systems for the optimization of home mechanical v... more The dissemination of the available telemedicine systems for the optimization of home mechanical ventilation (HMV) is prevented by the need of complex infrastructures. We developed a device which, once connected to Internet through the mobile phone network, allows an authorized physician connected to Internet to monitor the ventilator signals and modify the settings in real-time without the need of external data servers. The system was evaluated during experiments performed by tele-controlling a mechanical ventilator in Barcelona from Milano. A bench study verified the reliability and robustness of the system while an in-vivo test showed that it was possible to monitor and tele-control the ventilator to maintain the oxygen saturation of a rat ventilated in Barcelona subjected to interventions. Given that the system avoids the need for any complex telemedicine architecture and allows an individual and independent ventilator tele-control, it can be a new helpful tool to optimize HMV. Home mechanical ventilation, non-invasive mechanical ventilation, telemedicine.
B42. INVASIVE MECHANICAL VENTILATION: SOUP TO NUTS, 2010
2009 9th International Conference on Information Technology and Applications in Biomedicine, 2009
... CHRONIOUS: A Wearable System for the Management of Chronic Disease Patients Athanasios Papado... more ... CHRONIOUS: A Wearable System for the Management of Chronic Disease Patients Athanasios Papadopoulos, Dimitrios I. Fotiadis Senior Member, IEEE, Michael Lawo, Fabio Ciancitto, Christian Podolak, Raffaele L. Dellaca, Giulia Munaro, Roberto Rosso ...
Respiratory Physiology & Neurobiology, 2009
Breath-by-breath (BbB) oxygen uptake rate (V(O)(2)) was measured at the mouth (MO) and at the alv... more Breath-by-breath (BbB) oxygen uptake rate (V(O)(2)) was measured at the mouth (MO) and at the alveolar level, at the onset of square wave cycling exercise of moderate intensity in six healthy male subjects. Alveolar BbB V(O)(2) values were calculated correcting MO V(O)(2) values by (i) estimating (GR); and (ii) measuring (opto-electronic plethysmography, OEP) BbB lung O(2) store changes.V(O)(2) kinetics was then described by a bi-exponential model. GR yielded larger values of the time constants (tau2) of the primary phase of V(O)(2) kinetics. The mean response times (MRTs) calculated by analysing GR BbB V(O)(2) values were larger than (i) those obtained by using MO and OEP at 90W; and (ii) that by using MO at 120W. OEP corrected V(O)(2) yielded the highest normalised amplitude of the cardiodynamic phase of the V(O)(2) on-response. Correction of BbB V(O)(2) for actual BbB changes of lung O(2) stores by OEP thus seems more appropriate for the study of the early cardiodynamic phase of V(O)(2) kinetics than GR.
Journal of Applied Physiology, 2004
We simultaneously evaluated the mechanical response of the total respiratory system, lung, and ch... more We simultaneously evaluated the mechanical response of the total respiratory system, lung, and chest wall to changes in posture and to bronchoconstriction. We synthesized the optimal ventilation waveform (OVW) approach, which simultaneously provides ventilation and multifrequency forcing, with optoelectronic plethysmography (OEP) to measure chest wall flow globally and locally. We applied an OVW containing six frequencies from 0.156 to 4.6 Hz to the mouth of six healthy men in the seated and supine positions, before and after methacholine challenge. We measured mouth, esophageal, and transpulmonary pressures, airway flow by pneumotachometry, and total chest wall, pulmonary rib cage, and abdominal volumes by OEP. We computed total respiratory, lung, and chest wall input impedances and the total and regional transfer impedances (Ztr). These data were appropriately sensitive to changes in posture, showing added resistance in supine vs. seated position. The Ztr were also highly sensitiv...
Intensive Care Medicine, 2013
IEEE Transactions on Biomedical Engineering, 2005
Scanhead tracking by opto-electronic (OE) systems allows high accuracy in three-dimensional (3-D)... more Scanhead tracking by opto-electronic (OE) systems allows high accuracy in three-dimensional (3-D) freehand ultrasound imaging. In this paper, a new set of methods is proposed and compared with the standard approach [Gram-Schmidt method (GS)]. Three redundancy-based algorithms are introduced to compensate for possible loss of markers during data acquisition: regression plane (RP), multiple Gram-Schmidt (MGS), and center of mass least square (CMLS). When combined with the ultrasound instrument, the root-mean-squared (RMS) uncertainty in locating target points, over a working volume of 420 mm 490 mm 100 mm, improved by 7% and 24% using MGS and CMLS method respectively, compared to GS. A lower improvement was obtained with RP methods (5%), using the best marker configuration. In conclusion, CMLS method provides a robust and accurate procedure for 3-D freehand ultrasound scanhead tracking, able to manage possible loss of markers, with interesting perspectives for image fusion and body referenced 3-D ultrasound.
European Respiratory Journal, 2004
Expiratory flow limitation (EFL) during tidal breathing is a major determinant of dynamic hyperin... more Expiratory flow limitation (EFL) during tidal breathing is a major determinant of dynamic hyperinflation and exercise limitation in chronic obstructive pulmonary disease (COPD). Current methods of detecting this are either invasive or unsuited to following changes breath-by-breath. It was hypothesised that tidal flow limitation would substantially reduce the total respiratory system reactance (Xrs) during expiration, and that this reduction could be used to reliably detect if EFL was present. To test this, 5-Hz forced oscillations were applied at the mouth in seven healthy subjects and 15 COPD patients (mean¡SD forced expiratory volume in one second was 36.8¡11.5 % predicted) during quiet breathing. COPD breaths were analysed (n=206) and classified as flow-limited if flow decreased as alveolar pressure increased, indeterminate if flow decreased at constant alveolar pressure, or nonflow-limited. Of these, 85 breaths were flow-limited, 80 were not and 41 were indeterminate. Among other indices, mean inspiratory minus mean expiratory Xrs (DXrs) and minimum expiratory Xrs (Xexp,min) identified flow-limited breaths with 100% specificity and sensitivity using a threshold between 2.53-3.12 cmH 2 O?s?L-1 (DXrs) and-7.38-6.76 cmH 2 O?s?L-1 (Xexp,min) representing 6.0% and 3.9% of the total range of values respectively. No flow-limited breaths were seen in the normal subjects by either method. Within-breath respiratory system reactance provides an accurate, reliable and noninvasive technique to detect expiratory flow limitation in patients with chronic obstructive pulmonary disease.
Critical Care Medicine, 2001
Anesthesiology, 2001
Background A number of groups have recommended setting positive end-expiratory pressure during co... more Background A number of groups have recommended setting positive end-expiratory pressure during conventional mechanical ventilation in adults at 2 cm H2O above the lower corner pressure (P(CL)) of the inspiratory pressure-volume (P-V) curve of the respiratory system. No equivalent recommendations for the setting of the mean airway pressure (Paw) during high-frequency oscillation (HFO) exist. The authors questioned if the Paw resulting in the best oxygenation without hemodynamic compromise during HFO is related to the static P-V curve in a large animal model of acute respiratory distress syndrome. Methods Saline lung lavage was performed in seven sheep (28+/-5 kg, mean +/- SD) until the arterial oxygen partial pressure/fraction of inspired oxygen ratio decreased to 85+/-27 mmHg at a positive end-expiratory pressure of 5 cm H2O (initial injury). The PCL (20+/-1 cm H2O) on the inflation limb and the point of maximum curvature change (PMC; 26+/-1 cm H2O) on the deflation limb of the stat...
Neonatology and paediatric intensive care, 2021
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Papers by Raffaele Dellacà