The Evolution of Spacers and Valved Holding Chambers

Abstract

Spacers and valved holding chambers (VHCs) are pressurized metered dose inhaler (pMDI) accessory devices, designed to overcome problems that patients commonly experience when administering aerosol via a pMDI. Spacers were developed in direct response to patient-related issues with pMDI technique, particularly, poor coordination between actuation and inhalation, and local side-effects arising from oropharyngeal deposition. Current clinical guidelines indicate the need for widespread prescription and use of spacers, but, despite their apparent ubiquity, the devices themselves are, unfortunately, all too commonly "disused" by patients. An understanding of the background from which spacers developed, and the key factors influencing the optimization of the spacer and the later VHC, is crucial to developing an appreciation of the potential of these devices, both contemporary and future, for improving the delivery of pressurized aerosols to patients. This review, informed by a full patent search and an extensive scientific literature review, takes into account the clinical and laboratory evidence, commercial developments, and the sometimes serendipitous details of scientific anecdotes to form a comprehensive perspective on the evolution of spacers, from their origins, in the early days of the pMDI, up to the present day.

In Vitro Characterization of the OptiChamber Diamond Valved Holding Chamber

“…(1) In vitro work suggests that use of a VHC may reduce the impact of poor actuationinhalation coordination, even if the actuation-inhalation is completely mistimed. (2) Clinical studies have shown that use of a contemporary hydrofluoroalkane (HFA) pMDI with a VHC can increase lung deposition and attenuate oropharyngeal and gastrointestinal deposition, compared with delivery of the same formulation via a dry powder inhaler, (3,4) whereas in vitro work indicates that use of a pMDI with VHC can reduce oropharyngeal deposition relative to the pMDI alone.…”

Comparative Evaluation of Efficacy of Metered Dose Inhalers (Fluticasone and Salmeterol ) With Spacer and Without Spacer in Childhood Bronchial Asthma

“…6 In vivo studies demonstrated that reduced deposition of chemical in oropharynx and stomach and increased whole lung deposition of chemical by application of spacer. 3 …”

“…2 However, MDIs are not without their own issues which include patients' difficulties with their correct, coordinated use; many patients including the very young, confused, intellectually impaired, or those experiencing acute severe breathlessness will be unable to inhale in anything other than tidal breaths. 3 It is some of these issues that spacers are designed to overcome. Is MDI efficacy with spacer is equivalent to MDI without spacer when used for delivery of combination drugs (Fluticasone and salmeterol)?…”

Evaluación del conocimiento de la técnica de aerosolterapia con aerocámara por el equipo de salud pediátrico

“…La herramienta más utilizada para la Algunos autores mencionan la importancia de una correcta coaptación de la máscara, paso que la mayoría de los profesionales de salud incluidos en nuestro estudio menciona al realizar la encuesta (14)(15)(16).…”

“…RESULTADOS: Se incluyeron 71 profesionales. La técnica de aerosolterapia con aerocámara fue MUY BUENA en 15,49% (IC95% 8,(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)65), BUENA en 70,42% (IC95% 58,98-79,77) y REGULAR en 14,08% (IC95% 7,83-24,02) profesionales. La mediana de pasos realizados correctamente fue de 5 de 7 pasos.…”