Purpose: To determine the value of alveolar dead space as a predictor of weaning failure in mechanically ventilated COPD patients admitted to the intensive care units. Design: A prospective, observational cohort study conducted from 1 March 2014 to 31 August 2014. Setting: general Intensive care unit of Alexandria main University Hospitals. Patients: Eighty COPD patients requiring mechanical ve...

BACKGROUND Increased dead-space fraction is common in patients with persistent acute respiratory distress syndrome (ARDS). We evaluated the changes in the oxygenation and dead-space fraction in patients with persistent ARDS after corticosteroid therapy. METHODS This was a non-randomized non-placebo, controlled observational study including 19 patients with persistent ARDS treated with cortic...

The lungs normally are ventilated with enough air to dilute the carbon dioxide produced by metabolism, so that the partial pressure of carbon dioxide (Pco,) in the alveoli is kept remarkably close to 40 mm. Hg. It is the alveolar ventilation and not the total amount of air going in or out of the mouth (or 'minute-volume') that determines the Pco2 because a varying proportion of the total ventil...

BACKGROUND Homogeneous ventilation is important for prevention of ventilator-induced lung injury. Electrical impedance tomography (EIT) has been used to identify optimal PEEP by detection of homogenous ventilation in non-dependent and dependent lung regions. We aimed to compare the ability of volumetric capnography and EIT in detecting homogenous ventilation between these lung regions. METHOD...

During expiration, the carbon dioxide (CO2) levels inside the dead space of a filtering facepiece respirator (FFR) increase significantly above the ambient concentration. To reduce the CO2 concentration inside the dead space, we attach an active lightweight venting system (AVS) comprising a one-way valve, a blower and a battery in a housing to a FFR. The achieved reduction is quantified with a ...

BACKGROUND Chronic inflammation is a characteristic feature of diabetic cutaneous wounds. We sought to delineate novel mechanisms involved in the impairment of resolution of inflammation in diabetic cutaneous wounds. At the wound-site, efficient dead cell clearance (efferocytosis) is a pre-requisite for the timely resolution of inflammation and successful healing. METHODOLOGY/PRINCIPAL FINDIN...

BACKGROUND Electronic noses are composites of nanosensor arrays. Numerous studies showed their potential to detect lung cancer from breath samples by analysing exhaled volatile compound pattern ("breathprint"). Expiratory flow rate, breath hold and inclusion of anatomic dead space may influence the exhaled levels of some volatile compounds; however it has not been fully addressed how these fact...

The conventional McIntyre carrier multiplication theory for avalanche photodiodes (APD’s) does not adequately describe the experimental results obtained from APD’s with thin multiplication-regions. Using published data for thin GaAs and Al0 2Ga0 8As APD’s, collected from multiplication-regions of different widths, we show that incorporating dead-space in the model resolves the discrepancy. The ...