sorry here you go, it's from the Journal Cystic Fibrosis
Does repeated disinfection of the e-Flow rapid® nebulizer affect in vitro performance?
Lasha Bakuridzea, Véronique Andrieua, Christian Dupontb and Jean-Christophe Dubusc, ,
aLaboratoire de Pharmacie Galénique, Faculté de Pharmacie, Marseille, France
bCentre de Ressources et Compétences de la Mucoviscidose, Hôpital Cochin, Paris, France
cUnité de Médecine Infantile, EA3287-IFR125, and Centre de Ressources et Compétences de la Mucoviscidose, CHU Timone-Enfants, Marseille, France
Received 4 October 2006; revised 14 December 2006; accepted 22 December 2006. Available online 2 February 2007.
Abstract
Repeated disinfection of a nebulizer may modify its performance. During 60 cycles of disinfection with the Nuk® steam sterilizer (120 nebulizations), the median volume diameter of tobramycin or colistin, nebulization time and various parameters correlated with the membrane weight of the e-Flow rapid® are not modified. Results are similar when tap or purified water is used for washing and disinfection.
Keywords: Inhaled antibiotics; Cystic fibrosis; Nebulizer; Disinfection
Article Outline
1. Introduction
2. Materials and methods
3. Results
4. Discussion
Acknowledgements
References
1. Introduction
Repeated washing and disinfection of a nebulizer to guard against possible microbiological contamination with cystic fibrosis patients [1] and [2] may modify its performance [3]. With the new mesh nebulizer e-Flow rapid® (Pari GmbH, München, Germany), risk of obstruction of the multiple holes of the membrane by repeated use of drugs and/or disinfecting agents is usually evaluated by checking nebulization time once per month. This in vitro study examines possible modifications of the e-Flow rapid® performance when it is used with antibiotics (tobramycin or colistin) and disinfected with the recommended Nuk® steam sterilizer (Mapa GmbH, Zeven, Germany). As numerous patients, in practice, use purified water in the Nuk® to avoid potential sediments on the membrane due to hard water, we also compare how tap or purified water used during washing and disinfection may affect the membrane.
2. Materials and methods
The e-Flow rapid® was used as follows: (1) one nebulization with tobramycin (Tobi®, 300 mg/5 ml, Chiron Laboratories) or colistin (Colimycine®, prepared 5 min before use, 2,000,000 IU/6 ml, Aventis Laboratories); (2) nebulizer washed with liquid soap water for dishes (20% ionic and 5% non ionic surfactant), rinsed with clear water, and dried in ambient air; (3) a second nebulization with the same drug; (4) nebulizer washed and disinfected using the Nuk® for 15 min; (5) repetition of these four steps up to a total of 120 nebulizations. Three different groups were studied: one with tobramycin and another with colistin, both using tap water for all steps of washing, rinsing and disinfection; a third group, with tobramycin, used only purified water throughout the procedure.
For each group, we carried out 2 successive nebulizations measuring at baseline, after 30, 45 and 60 disinfection procedures: (1) median volume diameter (MVD, in ?m) with a Malvern laser diffraction; (2) nebulization time (in min) with a chronometer, stopped when a beep indicated the end of the nebulization; (3) several parameters linked to the weight of the membrane by gravimetric method with an electronic weighing machine (Sartorius, France) accurate to 10 ?g: weight before use (in g), difference in weight before and after each nebulization (in mg), increase in weight after 30, 45 and 60 cycles from baseline (in mg). Using 2 different brand-new e-Flow rapid® per group, a total of 4 measurements per parameter per group was obtained for each period of treatment. All the nebulizations were performed with active drugs under an extractor hood.
Results were expressed as mean and standard deviation. We did not perform statistical tests because only 2 devices were tested, with an impossibility to describe the inter-device variability.
3. Results
The principal results are shown in Table 1.
Table 1.
Values (mean ± standard deviation) of parameters obtained when nebulizing tobramycin and colistin with an e-Flow rapid®, disinfected with a Nuk® steam sterilizer, at baseline and after 30, 45, and 60 cycles of disinfection (n = 4 measurements per value)
--------------------------------------------------------------------------------
Tobramycin
--------------------------------------------------------------------------------
Colistin
--------------------------------------------------------------------------------
Tap water
--------------------------------------------------------------------------------
Purified water
--------------------------------------------------------------------------------
Tap water
--------------------------------------------------------------------------------
Median volume diameter (?m)
- at baseline 5.25 ± 0.24 5.29 ± 0.18 5.09 ± 0.2
- after 30 cycles 5.00 ± 0.30 5.23 ± 0.24 5.00 ± 0.14
- after 45 cycles 5.14 ± 0.16 5.17 ± 0.24 5.09 ± 0.24
- after 60 cycles 5.27 ± 0.13 5.27 ± 0.26 5.09 ± 0.18
Nebulization time (min)
- at baseline 6.02 ± 0.81 6.25 ± 0.45 4.04 ± 0.22
- after 30 cycles 5.52 ± 0.57 5.57 ± 0.57 4.48 ± 0.57
- after 45 cycles 5.75 ± 0.53 6.02 ± 0.61 4.10 ± 0.81
- after 60 cycles 6.25 ± 0.49 6.72 ± 0.58 4.51 ± 0.58
Membrane weight before use (g)
- at baseline 7.1469 ± 0.026 7.1475 ± 0.012 7.1692 ± 0.006
- after 30 cycles 7.1569 ± 0.027 7.1697 ± 0.006 7.1780 ± 0.005
- after 45 cycles 7.1562 ± 0.025 7.1657 ± 0.011 7.1827 ± 0.005
- after 60 cycles 7.1602 ± 0.027 7.1644 ± 0.011 7.1831 ± 0.005
When tap water was used for washing and disinfection, the median volume diameter and the nebulization time did not at any time during the experiment differ for tobramycin nebulization. The use of purified water did not alter the performance of the nebulizer used with tobramycin. Whatever the type of water used, the membrane weight difference before and after each nebulization was very low, ranging from ? 2.17 ± 1.41 mg to 0.47 ± 2.58 mg. The increase in weight from baseline with tobramycin was maximum 17 mg (i.e. less than 0.02% weight increase).
With colistin, there was a shorter nebulization time and a higher membrane weight than with tobramycin. MVD and nebulization time did not differ during the study period. The various parameters linked to the membrane weight were similar up to 60 cycles (difference in weight before and after use ranging from ? 0.05 ± 0.44 mg to 0.40 ± 0.94 mg; increase in weight from baseline of about 12 mg, despite eye-visible sediments seen on the membrane).
4. Discussion
Because of the wide range of nebulizers available and the diversity of cleaning methods used in home practice [4], more in vitro studies need to be conducted by independent laboratories before nebulizer cleaning methods can properly be assessed, both in terms of microbiological efficacy and of effects on the aerosol. Ideally, such studies should be based on a similar standardized methodology (type and quantity of microorganisms to be eradicated, nebulizer parameters to be measured, drug to be used, number of experiments to be repeated and nebulizers to be tested).
Although our study only focuses on the in vitro membrane performance of the e-Flow rapid®, our results address a major question concerning its use with different antibiotics and its washing and disinfection with Nuk® using tap or purified water. No alteration of the membrane is observed with the steam sterilization procedure up to 60 cycles (= 2 months of treatment), whatever the antibiotic or the type of water used. Of course, our study was limited to only 120 nebulizations, and drug output from the nebulizer was not directly evaluated. However, the various parameters linked to the weight of the membrane indirectly reflect the output rate. Despite the absence of microscopic evaluation to differentiate a problem of surface deposition or hole obstruction, they seem to indicate that the inhaled antibiotics used during the study period do not modify the membrane function.
Based on our results, we have no objective argument for recommending a more expensive procedure than tap water use with Nuk® to wash and disinfect the e-Flow rapid®.
Thanks
Thanks to the "Aerosol Group" of the French Cystic Fibrosis Society for stimulating discussions on this subject.
References
[1] L. Saiman and J. Siegel, Infection control recommendations for patients with cystic fibrosis: microbiology, important pathogens, and infection control practices to prevent patient-to-patient transmission, Infect Control Hosp Epidemiol 4 (2003), pp. S6 - S52. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (39)
[2] G. Reychler, K. Aarab, C. Van Ossel, J. Gigi, A. Simon and T. Leal et al., In vitro evaluation of efficacy of 5 methods of disinfection on mouthpieces and facemasks contaminated by strains of cystic fibrosis patients, J Cyst Fibros 4 (2005), pp. 183 - 187. SummaryPlus | Full Text + Links | PDF (98 K) | View Record in Scopus | Cited By in Scopus (5)
[3] T.A. Standaert, G.L. Morlin, J. Williams-Warren, J.P. Joy, M.S. Pepe and A. Weber et al., Effect of repetitive use and cleaning techniques of disposable jet nebulizers on aerosol generation, Chest 114 (1998), pp. 577 - 586. View Record in Scopus | Cited By in Scopus (19)
[4] M.K. Lester, P.A. Flume, S.L. Gray, D. Anderson and C.M. Bowman, Nebulizer use and maintenance by cystic fibrosis patients: a survey study, Respir Care 49 (2004), pp. 1504 - 1508. View Record in Scopus | Cited By in Scopus (5)
Does repeated disinfection of the e-Flow rapid® nebulizer affect in vitro performance?
Lasha Bakuridzea, Véronique Andrieua, Christian Dupontb and Jean-Christophe Dubusc, ,
aLaboratoire de Pharmacie Galénique, Faculté de Pharmacie, Marseille, France
bCentre de Ressources et Compétences de la Mucoviscidose, Hôpital Cochin, Paris, France
cUnité de Médecine Infantile, EA3287-IFR125, and Centre de Ressources et Compétences de la Mucoviscidose, CHU Timone-Enfants, Marseille, France
Received 4 October 2006; revised 14 December 2006; accepted 22 December 2006. Available online 2 February 2007.
Abstract
Repeated disinfection of a nebulizer may modify its performance. During 60 cycles of disinfection with the Nuk® steam sterilizer (120 nebulizations), the median volume diameter of tobramycin or colistin, nebulization time and various parameters correlated with the membrane weight of the e-Flow rapid® are not modified. Results are similar when tap or purified water is used for washing and disinfection.
Keywords: Inhaled antibiotics; Cystic fibrosis; Nebulizer; Disinfection
Article Outline
1. Introduction
2. Materials and methods
3. Results
4. Discussion
Acknowledgements
References
1. Introduction
Repeated washing and disinfection of a nebulizer to guard against possible microbiological contamination with cystic fibrosis patients [1] and [2] may modify its performance [3]. With the new mesh nebulizer e-Flow rapid® (Pari GmbH, München, Germany), risk of obstruction of the multiple holes of the membrane by repeated use of drugs and/or disinfecting agents is usually evaluated by checking nebulization time once per month. This in vitro study examines possible modifications of the e-Flow rapid® performance when it is used with antibiotics (tobramycin or colistin) and disinfected with the recommended Nuk® steam sterilizer (Mapa GmbH, Zeven, Germany). As numerous patients, in practice, use purified water in the Nuk® to avoid potential sediments on the membrane due to hard water, we also compare how tap or purified water used during washing and disinfection may affect the membrane.
2. Materials and methods
The e-Flow rapid® was used as follows: (1) one nebulization with tobramycin (Tobi®, 300 mg/5 ml, Chiron Laboratories) or colistin (Colimycine®, prepared 5 min before use, 2,000,000 IU/6 ml, Aventis Laboratories); (2) nebulizer washed with liquid soap water for dishes (20% ionic and 5% non ionic surfactant), rinsed with clear water, and dried in ambient air; (3) a second nebulization with the same drug; (4) nebulizer washed and disinfected using the Nuk® for 15 min; (5) repetition of these four steps up to a total of 120 nebulizations. Three different groups were studied: one with tobramycin and another with colistin, both using tap water for all steps of washing, rinsing and disinfection; a third group, with tobramycin, used only purified water throughout the procedure.
For each group, we carried out 2 successive nebulizations measuring at baseline, after 30, 45 and 60 disinfection procedures: (1) median volume diameter (MVD, in ?m) with a Malvern laser diffraction; (2) nebulization time (in min) with a chronometer, stopped when a beep indicated the end of the nebulization; (3) several parameters linked to the weight of the membrane by gravimetric method with an electronic weighing machine (Sartorius, France) accurate to 10 ?g: weight before use (in g), difference in weight before and after each nebulization (in mg), increase in weight after 30, 45 and 60 cycles from baseline (in mg). Using 2 different brand-new e-Flow rapid® per group, a total of 4 measurements per parameter per group was obtained for each period of treatment. All the nebulizations were performed with active drugs under an extractor hood.
Results were expressed as mean and standard deviation. We did not perform statistical tests because only 2 devices were tested, with an impossibility to describe the inter-device variability.
3. Results
The principal results are shown in Table 1.
Table 1.
Values (mean ± standard deviation) of parameters obtained when nebulizing tobramycin and colistin with an e-Flow rapid®, disinfected with a Nuk® steam sterilizer, at baseline and after 30, 45, and 60 cycles of disinfection (n = 4 measurements per value)
--------------------------------------------------------------------------------
Tobramycin
--------------------------------------------------------------------------------
Colistin
--------------------------------------------------------------------------------
Tap water
--------------------------------------------------------------------------------
Purified water
--------------------------------------------------------------------------------
Tap water
--------------------------------------------------------------------------------
Median volume diameter (?m)
- at baseline 5.25 ± 0.24 5.29 ± 0.18 5.09 ± 0.2
- after 30 cycles 5.00 ± 0.30 5.23 ± 0.24 5.00 ± 0.14
- after 45 cycles 5.14 ± 0.16 5.17 ± 0.24 5.09 ± 0.24
- after 60 cycles 5.27 ± 0.13 5.27 ± 0.26 5.09 ± 0.18
Nebulization time (min)
- at baseline 6.02 ± 0.81 6.25 ± 0.45 4.04 ± 0.22
- after 30 cycles 5.52 ± 0.57 5.57 ± 0.57 4.48 ± 0.57
- after 45 cycles 5.75 ± 0.53 6.02 ± 0.61 4.10 ± 0.81
- after 60 cycles 6.25 ± 0.49 6.72 ± 0.58 4.51 ± 0.58
Membrane weight before use (g)
- at baseline 7.1469 ± 0.026 7.1475 ± 0.012 7.1692 ± 0.006
- after 30 cycles 7.1569 ± 0.027 7.1697 ± 0.006 7.1780 ± 0.005
- after 45 cycles 7.1562 ± 0.025 7.1657 ± 0.011 7.1827 ± 0.005
- after 60 cycles 7.1602 ± 0.027 7.1644 ± 0.011 7.1831 ± 0.005
When tap water was used for washing and disinfection, the median volume diameter and the nebulization time did not at any time during the experiment differ for tobramycin nebulization. The use of purified water did not alter the performance of the nebulizer used with tobramycin. Whatever the type of water used, the membrane weight difference before and after each nebulization was very low, ranging from ? 2.17 ± 1.41 mg to 0.47 ± 2.58 mg. The increase in weight from baseline with tobramycin was maximum 17 mg (i.e. less than 0.02% weight increase).
With colistin, there was a shorter nebulization time and a higher membrane weight than with tobramycin. MVD and nebulization time did not differ during the study period. The various parameters linked to the membrane weight were similar up to 60 cycles (difference in weight before and after use ranging from ? 0.05 ± 0.44 mg to 0.40 ± 0.94 mg; increase in weight from baseline of about 12 mg, despite eye-visible sediments seen on the membrane).
4. Discussion
Because of the wide range of nebulizers available and the diversity of cleaning methods used in home practice [4], more in vitro studies need to be conducted by independent laboratories before nebulizer cleaning methods can properly be assessed, both in terms of microbiological efficacy and of effects on the aerosol. Ideally, such studies should be based on a similar standardized methodology (type and quantity of microorganisms to be eradicated, nebulizer parameters to be measured, drug to be used, number of experiments to be repeated and nebulizers to be tested).
Although our study only focuses on the in vitro membrane performance of the e-Flow rapid®, our results address a major question concerning its use with different antibiotics and its washing and disinfection with Nuk® using tap or purified water. No alteration of the membrane is observed with the steam sterilization procedure up to 60 cycles (= 2 months of treatment), whatever the antibiotic or the type of water used. Of course, our study was limited to only 120 nebulizations, and drug output from the nebulizer was not directly evaluated. However, the various parameters linked to the weight of the membrane indirectly reflect the output rate. Despite the absence of microscopic evaluation to differentiate a problem of surface deposition or hole obstruction, they seem to indicate that the inhaled antibiotics used during the study period do not modify the membrane function.
Based on our results, we have no objective argument for recommending a more expensive procedure than tap water use with Nuk® to wash and disinfect the e-Flow rapid®.
Thanks
Thanks to the "Aerosol Group" of the French Cystic Fibrosis Society for stimulating discussions on this subject.
References
[1] L. Saiman and J. Siegel, Infection control recommendations for patients with cystic fibrosis: microbiology, important pathogens, and infection control practices to prevent patient-to-patient transmission, Infect Control Hosp Epidemiol 4 (2003), pp. S6 - S52. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (39)
[2] G. Reychler, K. Aarab, C. Van Ossel, J. Gigi, A. Simon and T. Leal et al., In vitro evaluation of efficacy of 5 methods of disinfection on mouthpieces and facemasks contaminated by strains of cystic fibrosis patients, J Cyst Fibros 4 (2005), pp. 183 - 187. SummaryPlus | Full Text + Links | PDF (98 K) | View Record in Scopus | Cited By in Scopus (5)
[3] T.A. Standaert, G.L. Morlin, J. Williams-Warren, J.P. Joy, M.S. Pepe and A. Weber et al., Effect of repetitive use and cleaning techniques of disposable jet nebulizers on aerosol generation, Chest 114 (1998), pp. 577 - 586. View Record in Scopus | Cited By in Scopus (19)
[4] M.K. Lester, P.A. Flume, S.L. Gray, D. Anderson and C.M. Bowman, Nebulizer use and maintenance by cystic fibrosis patients: a survey study, Respir Care 49 (2004), pp. 1504 - 1508. View Record in Scopus | Cited By in Scopus (5)