Titolo del documento

Metered dose inhaler add-on devices: is the inhaled mass of drug depenedent on the size of the infant ?

Autori e Nazionalità

Tupeinen M, Nikander K, Malmberb LP, Pelkonen A. Finlandia

Fonte bibliografica

J Aerosol Med 1999;12:171-176. 

Lingua

Inglese

Abstract

Limited cooperation and low tidal volumes in infants make aerosol therapy difficult. We measured the amount of drug delivered from two baby spacer devices especially developed for use in infants. Designed as a randomized crossover study, aerolized budesonide from a pressurized metered dose inhaler (pMDI) was collected in the inspiratory filter interposed between the face mask and the spacer in 13 infants aged from 2 to 19 months old. The study was performed in connection with pulmonary function testing with a plethysmograph, and the children were sedated with cloral hydrate. Two small-volume baby spacer devices were used: a Babyhaler spacer (GlaxoWellcome, Hertfordshire, UK) made of polycarbonate with a volume of 350 mL and a built-in dead space of 40 mL and a NebuChamber spacer (AstraZeneca, Lund, Sweden) made of stainless steel with a volume of 250 mL and no dead space. Budesonide delivery from the NebuChamber was significantly higher than from the Babyhaler: 38.2% (range, 28.3%-47.5%) of the nominal dose versus 12% (range, 3.3%-21.25%) of the nominal dose of 400 micrograms of budesonide (P = 0.002). The inhaled mass of budesonide from the Babyhaler correlated significantly with skin surface area (r = 0.68, P = 0.018), weight (r = 0.66, P = 0.019), height (r = 0.69; P = 0.017), tidal volume (r = 0.82; P = 0.004), and minute volume (r = 0.67; P = 0.019). No correlations were found between these variables and the inhaled mass of budesonide from the NebuChamber. The results indicate that the design of the NebuChamber spacer affords stable drug delivery in infants and that a large variability in the inhaled mass of drug may be found when infants are inhaling from different baby spacers.

PMID

10623333 [PubMed - indexed for MEDLINE]

Tipo di studio

Osservazionale

Livello di evidenza

2+ 

Commento

Il disegno è il materiale della Nebuchamber di metallo consente di ottenere una minor variabilità nella dose di farmaco inalata rispetto al Babyhaler, che  possiede anche un notevole spazio morto fra le valvole di 40 ml.

Titolo del documento

Force-dependent static dead space of face masks used with holding chambers.

Autori e Nazionalità

Shaha SA, Berlinski AB, Rubin BK. Usa

Fonte bibliografica

Respir Care 2006;51:140-144.

Lingua

Inglese

Abstract

BACKGROUND: Pressurized metered-dose inhalers with valved holding chambers and masks are commonly used for aerosol delivery in children. Drug delivery can decrease when the dead-space volume (DSV) of the valved holding chamber is increased, but there are no published data evaluating force-dependent DSV among different masks. METHODS: Seven masks were studied. Masks were sealed at the valved holding chamber end and filled with water to measure mask volume. To measure mask DSV we used a mannequin of 2-year-old-size face and we applied the mask with forces of 1.5, 3.5, and 7 pounds. Mask seal was determined by direct observation. Intra-brand analysis was done via analysis of variance. RESULTS: At 3.5 pounds of force, the DSV ranged from 29 mL to 100 mL, with 3 masks having DSV of < 50 mL. The remaining masks all had DSV > 60 mL. At 3.5 pounds of force, DSV percent of mask volume ranged from 33.7% (Aerochamber, p < 0.01 compared with other masks) to 100% (Pocket Chamber). DSV decreased with increasing force with most of the masks, and the slope of this line was inversely proportional to mask flexibility. Mask fit was 100% at 1.5 pounds of force only with the Aerochamber and Optichamber. Mask fit was poorest with the Vortex, Pocket Chamber, and BreatheRite masks. CONCLUSION: Rigid masks with large DSV might not be not suitable for use in children, especially if discomfort from the stiff mask makes its use less acceptable to the child.

PMID

16441958 [PubMed - indexed for MEDLINE]

Tipo di studio

Osservazionale

Livello di evidenza

2+

Commento

Lo spazio morto diminuisce con l'aumentare della forza con cui la maschera viene applicata al viso. Modelli rigidi come quelli usati sul Vortex sono pertanto poco adatti e spesso mal tollerati dal paziente

Titolo del documento

Infant aerosol holding chambers facemasks: not alla are born equally ! Respir Care 2006;51:123-125.

Autori e Nazionalità

Amirav I. Israele 

Fonte bibliografica

Respir Care 2006;51:123-125

Lingua

Inglese

Abstract

testo

PMID

16441955 [PubMed - indexed for MEDLINE]

Tipo di studio

Editoriale ad un articolo inserito nella stessa rivista 

Livello di evidenza

4

Commento

Non tutte le maschere sono uguali: è importante saperlo, perchè quelle rigide devono essere applicate in modo molto aderente al viso e ciò comporta sconforto per il paziente: questo perchè con le maschere rigide lo spazio morto si riduce meno che con quelle morbide, man mano che si aumenta la loro pressione sul viso del paziente

Titolo del documento

Aerosol delivery to young children by pMMDI-spacer: is facemask design important ?  

Autori e Nazionalità

Esposito-Festen J, Ates B, van Vliet F, Hop W, Tiddens H. Olanda 

Fonte bibliografica

Pediatr Allergy Immunol 2005;16:348-353

Lingua

Inglese

Abstract

This study aimed at identifying in a daily-life setting the influence of facemask design on drug delivery via a spacer to young children. In a 4-week randomized crossover study, 24 children (7-23-months old) with recurrent wheeze tested the AstraZeneca, Galemed, and Hans Rudolph facemask combined with the NebuChamber at home. Each mask was tested twice daily for seven consecutive days. Filters positioned between the NebuChamber and facemask trapped the budesonide aerosol (200 microg, Pulmicort). Parents were asked to score the child's degree of cooperation during administration on diary cards. The administration procedure was evaluated through video recordings. Mean filter dose (standard deviation (s.d.)), expressed as % of nominal dose, was 39% (14), 47% (12), and 42% (11) for the AstraZeneca, the Galemed and the Hans Rudolph mask, respectively. Irrespective of the degree of cooperation, the Galemed mask gave significantly higher mean filter doses than the other masks (level of significance) (p < 0.045). Median (range) within-subject dose variability, expressed, as coefficient of variation (CV), was 37% (19-255), 32% (9-114), and 30% (9-115) for the AstraZeneca mask, the Galemed mask and the Hans Rudolph mask, respectively, not significant. Dose variability increased with decreasing cooperation for all three masks (p = 0.007). Drug delivery to young children with recurrent wheeze by means of the NebuChamber can be enhanced using the Galemed facemask. Dose variability seems to be independent of facemask design but mainly depends on cooperation

PMID

15943599 [PubMed - indexed for MEDLINE]

Tipo di studio

Osservazionale

Livello di evidenza

3

Commento

Per gli autori di questo studio svolge un ruolo più importante nell'influenzare la quota di farmaco inalata, la collaborazione del bambino rispetto al disegno della maschera

Titolo del documento

Redesigned face mask improves "real life" aerosol delivery for Nebuchamber. 

Autori e Nazionalità

Amirav I, Mansour Y, Mandelberg A, Bar-Ilan I, Newhouse MT.Israele

Fonte bibliografica

Pediatr Pulmonol 2004;37:172-177. 

Lingua

Inglese

Abstract

The currently available facemask interface for the Nebuchamber (N) valved-holding chamber (VHC) provides a very poor seal to the face, which, on average, decreases the aerosol dose and was previously shown to increase the variability of aerosol delivery. The efficiency of a redesigned mask (RD) for the Nebuchamber with a potentially better seal was compared to the standard mask (SM) supplied with the N in a randomized real-life crossover clinical trial. Twenty children (mean age, 26 +/- 10 months) were randomized to use the Nebuchamber for 1 week with the old mask and then for another week with the newer mask, and vice versa. Filters, changed daily, inserted between the mask and the VHC, trapped the delivered drug (budesonide). The dose of budesonide was quantified by high-performance liquid chromatography (HPLC). Use of the redesigned mask improved aerosol delivery to the filter by 30%, compared to the SM (mean 28.1 +/- 7.7% of nominal dose with RD vs. 21.6 +/- 9.6% with SM, P = 0.017). The relatively high within-subject variability in aerosol delivery (36-38%) did not change, however. Facemasks are arguably the most important determinants of aerosol delivery. The newly developed RD for the Nebuchamber proved to be considerably more efficient than the SM for aerosol delivery to young children. Patient-related factors may be more important with respect to the variability observed

PMID

14730663 [PubMed - indexed for MEDLINE]

Tipo di studio

Osservazionale

Livello di evidenza

2+

Commento

La maschera della Nebuchamber di metallo permette una scarsa adesione al volto del paziente con una grande variabilità della dose inalata. Dovrebbe pertanto essere ridisegnata

Titolo del documento

Aerosol therapy with valved holding chambers in young childre: importance of the facemask seal 

Autori e Nazionalità

Amirav I, Newhouse MT. Israele 

Fonte bibliografica

Pediatrics 2001;108:389-394 

Lingua

Abstract

OBJECTIVE: Masks are an essential interface between valved holding chambers (VHCs), or spacers, and a small child's face for providing aerosol therapy. Clinical experience suggests that many young children do not cooperate with the VHC treatment or tolerate a mask of any kind. This might impair the mask-face seal and reduce the dose delivered to the child. The objective of this study was to evaluate the ability of parents to provide a good mask-face seal in infants and toddlers using 3 masks provided with commonly used pediatric VHCs and compare this with the seal obtained with the Hans Rudolph pediatric anesthesia mask. METHODS: A preliminary in vitro filter study was conducted to validate the assumption that reduced ventilation as a result of increased facemask leak reduces the drug aerosol dose delivered to the mouth. Facemask leak then was studied in vivo for NebuChamber, AeroChamber, BabyHaler, and Hans Rudolph masks by measuring ventilation with an in-line pneumotachograph while the facemask was held in place by experienced parents who were asked to demonstrate how they deliver medication to their children without any additional instruction. Thirty children (mean age: 3.2 +/- 1.4 years) performed 4 repeat studies with each mask. The first 10 patients performed the tests once again within 1 month. On the second occasion, the parents were coached continuously and encouraged to hold the mask tightly against the child's face. RESULTS: The AeroChamber and Hans Rudolph masks provided the best seal as reflected in the magnitude of the ventilation measured through them. The NebuChamber provided the poorest seal, with 45% less ventilation than the AeroChamber and Hans Rudolph masks. There was considerable intraindividual variability for all masks (24% to 48%); however, the variability with the NebuChamber mask was 2-fold greater than the other masks. All ventilatory volumes during the coached session were significantly greater than during the uncoached session. Variability during the coached session was significantly less (except for the BabyHaler, which remained unchanged). CONCLUSIONS: VHCs with masks designed for use with small children may provide a poor seal with the face, leading to reduced or more variable dose delivery. The facemask seal is critical for efficient aerosol delivery to infants and young children, and this should be stressed to parents.

PMID

11483804 [PubMed - indexed for MEDLINE

Tipo di studio

Osservazionale,  eseguito in laboratorio

Livello di evidenza

3

Commento

il grado di adesione della maschera facciale al viso è critico ai fini della quantità della dose inalata e della sua variabilità

Titolo del documento

Spacers and holding chambers: not the last word, we hope.

Autori e Nazionalità

Mitchell JP. Canada

Fonte bibliografica

Arch Dis Child 2001;84:89

Lingua

Inglese

Abstract

L'autore di questa lettera è direttore scientifico di un laboratorio di ricerca per aerosol: risponde a Zar che in un precedente articolo aveva dimostrato che un distanziatore di plastica fatto in casa derivato da una bottiglia delle bibite e senza valvole poteva essere utilizzato con la stessa efficacia di uno spacer commerciale dotato di valvole per somministrare i broncodilatatori nell'attacco acuto d'asma: Mitchell sostiene l'utilità delle valvole: perchè si evita la ri-immissione di aria nel distanziatore e perchè vengono trattenute le particelle più grossolane del farmaco, responsabili dell'impatto nelle alte vie respiratorie e nel cavo orale 

PMID

Tipo di studio

Opinione di esperto

Livello di evidenza

4  

Commento

Titolo del documento

Aerosol delivery to non-ventilated infants by metered dose inhaler: should a valved spacer be used ?

Autori e Nazionalità

Fok TF, Lam K, Chan CK, NG PC, Zhuang H, Wong W, Cheung Kl.Cina

Fonte bibliografica

Pediatr Pulmonol 1997;24:204-12

Lingua

Inglese

Abstract

In a randomized double-blind cross-over study on 20 spontaneously breathing, oxygen-dependent preterm infants who had received positive pressure ventilation for respiratory distress syndrome, we tested the hypothesis that the one-way non-rebreathing valves of aerosol spacer devices might impair rather than enhance the delivery of aerosols to small infants by metered dose inhalers (MDI). Ten infants were given 2 doses (200 micrograms/dose) of MDI albuterol through a neonatal Aerochamber 4 h apart. At random sequence, one dose was delivered with the non-rebreathing valve of the Aerochamber in place; for the other dose, the valve had been removed. The experiment was repeated on another ten infants using a different spacer device (Babyhaler) with or without its one-way inspiratory valve removed. During the first hour following aerosol administration, use of the non-valved spacers was associated with a significantly greater degree of tachycardia in both groups, and also lower transcutaneous carbon dioxide tension in the Aerochamber group. All infants showed a reduction in respiratory system resistance and an improvement in functional residual capacity following albuterol treatment. In both groups, maximum reduction in respiratory system resistance, recorded 30 min after aerosol delivery, was significantly greater following the use of the non-valved spacers (Aerochamber: 51.2 +/- 3.1% vs. 35.0 +/- 2.8%, P < 0.0001; Babyhaler: 38.8 +/- 2.3% vs. 19.2 +/- 1.4%, P < 0.0001) than following the use of the spacers with a valve. The findings provide indirect evidence supporting our hypothesis and suggest that when the MDI is used to deliver therapeutic aerosols to non-ventilated newborns or small infants, a spacer device without a non-rebreathing valve should be used

PMID

9330417 [PubMed - indexed for MEDLINE]

Tipo di studio

Osservazionale

Livello di evidenza

3

Commento

L'uso di una valvola sia nell'Aerochamber che nel Babyhaler determina una maggior riduzione delle resistenze respiratorie rispetto all'uso degli stessi apparecchi senza valvole quando si somministra  salbutamolo

Titolo del documento

Pressure flow characteristics of the valve in spacer devices.

Autori e Nazionalità

Sennhauser FH, Sly PD. Australia 

Fonte bibliografica

Arch Dis Child 1989;64:1305-7

Lingua

Inglese

Abstract

The valve system in the mouth piece of two spacer devices was analysed. Pressures required to open and close the non-rebreathing valve were very low (less than 0.1 kPa). Inspiratory flow requirements were within physiological limits for infants' normal tidal breathing. Expiratory flow requirements varied significantly, and the flow required to prevent rebreathing from the chamber may exceed the physiological flow limits for normal tidal breathing.

PMID

2817951 [PubMed - indexed for MEDLINE]

Tipo di studio

Osservazionale

Livello di evidenza

3

Commento