Amira S.A. Said

In vitro/in vivo correlation and modeling of emitted dose and lung deposition of inhaled salbutamol from metered dose inhalers with different types of spacers in noninvasively ventilated patients

Abstract Substituting spacer by another in noninvasive ventilation (NIV) involves many variables, e.g. total emitted dose (TED), mass median aerodynamic diameter (MMAD), type of spacer, total lung deposition and total systemic absorption, which must be adjusted to ensure patient optimum therapy. Data mining based on artificial neural networks and genetic algorithms were used to model in vitro inhalation process, predict and optimize bioavailability from inhaled doses delivered by metered dose inhaler (MDI) using different spacers in NIV. Modeling of data indicated that in vitro performance of MDI-spacer systems was dependent mainly on fine particle dose (FPD), fine particle fraction (FPF), MMAD and to lesser extent on spacer type. Ex vivo model indicated that amount of salbutamol collected on facemask filter was directly affected by FPF. In vivo model (24hQ) depended directly on spacer type, FPF and TED. Female patients showed higher 0.5hQ and 24hQ values than males. AeroChamber VC spacer demonstrated higher TED and 24hQ in vivo values. Results indicated suitability of MDI-spacer systems in achieving appropriate in vitro inhalation performance. The possibility of modeling and predicting both ex vivo and in vivo capabilities of MDI-spacer systems from knowledge of in vitro attributes enabled detailed focus on important variables required to deliver safe and accurate doses of salbutamol to ventilated patients.

Modelling of in-vitro and in-vivo performance of aerosol emitted from different vibrating mesh nebulisers in non-invasive ventilation circuit

&NA; Substituting nebulisers by another in non‐invasive ventilation circuit (NIV) involves many process variables which must be adjusted to ensure patient optimum therapy. However, there is a doubt when nebulisers use the same technology. Data mining technology based on artificial neural networks and genetic algorithms were used here to model in‐vitro inhalation process and predict bioavailability from inhaled doses delivered by three different vibrating mesh nebulisers (VMNs) in NIV. Modelling of data indicated that in‐vitro performance of VMNs was dependent mainly on fine particle fraction, mass median aerodynamic diameter (MMAD), total emitted dose (TED) and to lesser extent on nebuliser type. Ex‐vivo model indicated that amount of salbutamol collected on facemask filter was directly affected by TED. In‐vivo model showed that amount of salbutamol deposited into the lung (0.5 hQ) and amount absorbed systemically (24 hQ) were dependent directly on MMAD and TED. Female patients showed higher 24 hQ values than males. Nebuliser type affected TED, 0.5 hQ but not 24 hQ values. Results indicate suitability of VMNs in achieving appropriate in‐vitro inhalation performance model. The results also, indicate that the three VMNs are comparable and can be interchanged with no fear of any additional toxicity. Graphical abstract Figure. No caption available.

In vitro aerodynamic characteristics of aerosol delivered from different inhalation methods in mechanical ventilation

Abstract Aerodynamic characteristics of aerosol delivery during invasive mechanical ventilation (IMV) are mostly determined by inserting cascade impactor in the circuit. Impactor might have some effect on airflow within IMV. Hence, the aim of the present study was to develop and evaluate new in vitro aerodynamic characterization methodology without affecting airflow in IMV. Breathing simulator was set in standard adult IMV circuit with inspiratory and expiratory pressures of 20 and 5 cm H2O, 1:3 inspiratory–expiratory ratio, 15 breaths min−1, and tidal volume of 500 ml. Two ml of salbutamol solution containing 10,000 μg was nebulized using three different vibrating mesh nebulizers (VMNs) and Sidestream jet nebulizer (JET). Sixteen-metered doses, containing 100 μg salbutamol each, were delivered using three different spacers. Each device was placed in inspiration limb of Y-piece of ventilator tubing. Aerodynamic characteristics of aerosol delivered were measured using cooled Andersen cascade impactor, with mixing inlet connected to it. VMNs used had significantly more total mass in the impactor (p < .001) and fine particle dose (p < .001) compared to JET. Spacers used had higher total mass in the impactor percent (p < .001) and fine particle fraction compared to nebulizers. The in vitro IMV methodology setting suggested here showed encouraging results in comparison of different aerosol delivery systems in intubated patient.

Efficacy and safety of combined vs. single renin-angiotensin-aldosterone system blockade in chronic kidney disease -

Hypertension and proteinuria are well-known predictors of chronic kidney disease (CKD) progression. Therapeutic interventions have different magnitude of albuminuria and hypertension. This study was designed to evaluate the efficacy and safety of combined vs. single renin-angiotensin-aldosterone system (RAAS) blockade in chronic kidney disease. Forty (28 female) patients with chronic kidney diseases were collected from nephrology outpatient clinic, internal medicine department, Beni Suef University hospital. They were divided randomly into 2 groups. Group A was 24 (20 females) patients treated with Enalapril, as angiotensin converting enzyme inhibitor (ACE-I) alone. Group B was 16 (8 females) patients treated with combination of Enalapril and Irbesartan, as angiotensin receptor blocker (ARB). All patients were subjected to full history taking; thorough clinical examination; certain laboratory tests and renal function tests at the start of the study, 1.5 and 3 months later. Proteinuria, urinary albumin/creatinine ratio (UACR), systolic blood pressure (SBP) and glomerular filtration rate (GFR) were significantly (p