Salbutamol Transport and Deposition in the Upper and Lower Airway with Different Devices in Cats: A Computational Fluid Dynamics Approach

Abstract

Pressurized metered-dose inhalers (pMDI) with or without spacers are commonly used for the treatment of feline inflammatory airway disease. During traditional airways treatments, a substantial amount of drugs are wasted upstream of their target. To study the efficiency of commonly used devices in the transport of inhaled salbutamol, different computational models based on two healthy adult client-owned cats were developed. Computed tomographic images from one cat were used to generate a three-dimensional geometry, and two masks (spherical and conical shapes) and two spacers (10 and 20 cm) completed the models. A second cat was used to generate a second model having an endotracheal tube (ETT) with and without the same spacers. Airflow, droplet spray transport, and deposition were simulated and studied using computational fluid dynamics techniques. Four regions were evaluated: device, upper airways, primary bronchi, and downstream lower airways/parenchyma (“lung”). Regardless of the model, most salbutamol is deposited in devices and/or upper airways. In the first model, particles reaching the lung varied between 5.8 and 25.8%. Compared with the first model, pMDI application through the ETT with or without a spacer had significantly higher percentages of particles reaching the lung (p = 0.006).

Breathe easy: inhalational therapy for feline inflammatory airway disease

“…The influence of spherical vs conical masks over the muzzle, shorter vs longer spacer devices and actuation through an endotracheal tube was specifically investigated. 44…”

“…Computational fluid dynamics represents a means of non-invasively modeling conditions to study aerosol transport and deposition, and has been applied to cats. 44 Nine different combinations of devices were modeled using CT images of client-owned cats, allowing for assessment of pMDI delivery of albuterol (salbutamol). The influence of spherical vs conical masks over the muzzle, shorter vs longer spacer devices and actuation through an endotracheal tube was specifically investigated.…”

Inhalative Therapie chronischer Erkrankungen der unteren Atemwege bei Hund und Katze – eine Literaturübersicht

“…Terbutalin ist als Injektionslösung verfügbar, wodurch es bei Katzen im Status asthmaticus zur Notfalltherapie geeignet ist 15 , 19 , 52 , 71 . SAL ist ein inhalativer, schnell- und kurzwirksamer ß2-AA.…”

“…SAL ist ein inhalativer, schnell- und kurzwirksamer ß2-AA. Bei Tieren, welche bereits an eine IK gewöhnt sind, kann inhalatives SAL bei Bronchospasmus auch als Notfallmedikament eingesetzt werden 15 , 33 , 71 .…”

Effect of MDI Actuation Timing on Inhalation Dosimetry in a Human Respiratory Tract Model

“…Moreover, clinical trials of OIDPs with either lab animals or human subjects can take years to complete [7][8][9]. Surrogate computational fluid dynamics (CFD) simulations have become increasingly important in providing comparable results and deposition details [10,11]. However, an accurate CFD predicted dosimetry requires a precise representation of the drug properties, respiratory geometry, and breathing condition.…”