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Objective? To? analyze? the? ineffective? triggering? caused? by? nebulization? in? the? way? of?respiratory?mechanics.? Methods? A?test-lung?and?an?oxygen-driven?jet?nebulizer?were?connected?to?the?circuit?in?a?PB840?ventilator.?The?test-lung?was?pulled?outwards?in?manual?way?till?an?inspiration?was?effectively?triggered?separately?in?different?flow-trigger?modes?[flow-trigger?sensitivity?(VTrig)?3?L/min?and?5?L/min]?and?pressure-trigger?modes?[pressure-trigger?sensitivity?(PTrig)?2?cmH2O?and?4?cmH2O,?1?cmH2O?=?0.098?kPa]?with?the?nebulizer?being?closed?and?opened?in?turn.?The?corresponding?relationship?and?characteristics?between?the?flow?and?pressure?in?the?circuit?under?different?triggering?conditions?were?observed?by?adjusting?the?curve?amplitude?in?the?screen.?The?minimum?alveolar?pressure?(Pa)?which?could?cause?an?effective?triggering?and?the?variation?span?of?Pa?during?the?triggering?period?were?analyzed?in?respiratory?mechanics.? Results? ①?In?flow-trigger?mode:?Pa?was?pulled?down? from? positive? end-expiratory? pressure? (PEEP)? or? intrinsic? positive? end-expiratory? pressure? (PEEPi)? to?"PEEP－VTrigR"?(R?meant?airway?resistance)?without?nebulization,?and?the?span?of?Pa?was?"VTrigR"?or?"PEEPi－PEEP+VTrigR".?Pa?was?pulled?down?from?PEEP?or?PEEPi?to?"PEEP－(VTrig+N)?R"?(N?meant?nebulization?airflow)?with?nebulization,?and?the?span?of?Pa?was?"(VTrig+N)?R"?or?"PEEPi－PEEP+(VTrig+N)?R".?②?In?pressure-trigger?mode:?Pa?was?pulled?down?from?PEEP?or?PEEPi?to?"PEEP－PTrig－1R"?without?nebulization,?and?the?span?of?Pa?was?"PTrig+1R"?or?"PEEPi－PEEP+PTrig+1R".?Pa?was?pulled?down?from?PEEP?or?PEEPi?to?"PEEP－PTrig－(N+1)?R"?with?nebulization,?and?the?span?of?Pa?was?"PTrig+(N+1)?R"?or?"PEEPi－PEEP+PTrig+(N+1)?R".? ?Conclusions? Nebulization?airflow?increases?the?difficulty?of?inspiratory?triggering?in?mechanical?ventilation.?PEEPi?makes?it?more?difficult.
RESUMEN
Objective To analyze and compare in vitro deposition results of budesonide inhalation suspension made by 3 jet nebulizers. Methods Self-made budesonide inhalation suspension was selected as a model drug, and the in vitro deposition properties was determined by breathing simulator and the next generation pharmaceutical impactor (NGI) with Pari Turob BOY N?BOY SX and Omron NE-C28 nebulizers. Results The mass median aerodynamic diameter (MMAD) of aerosol measured with the three kinds of nebulizers ranged between 4.95 and 6.54 µm, geometric standard deviation(GSD)ranged between 1.66 and 2.10,fine particle dose (FPD) ranged between 87.64 and 101.47 µg and fine particle fraction (FPF) ranged between 37.75% and 53.88%. Delivery rates of Pari Turob BOY N and BOY SX were similar, while the delivery rate of Omron NE-C28 was low. The total delivery of each nebulizer was about 0.11 µg. Statistical analysis showed that different nebulizer had no significant difference on delivered dose, but had significant difference on delivered rate(P<0.01)and aerodynamic measurement results(P<0.05). Conclusion Different jet nebulizers for budesonide inhalation suspension have certain influence on its in vitro deposition. The suitability of the Omron NE-C28 is the best among the three kinds of nebulizers.
RESUMEN
Objective To analyze and compare in vitro deposition results of budesonide inhalation suspension made by 3 jet nebulizers. Methods Self-made budesonide inhalation suspension was selected as a model drug,and the in vitro deposition proper?ties was determined by breathing simulator and the next generation pharmaceutical impactor(NGI)with Pari Turob BOY N、BOY SX and Omron NE-C28 nebulizers. Results The mass median aerodynamic diameter(MMAD)of aerosol measured with the three kinds of nebulizers ranged between 4.95 and 6.54μm,geometric standard deviation(GSD)ranged between 1.66 and 2.10,fine particle dose (FPD)ranged between 87.64 and 101.47μg and fine particle fraction(FPF)ranged between 37.75%and 53.88%. Delivery rates of Pari Turob BOY N and BOY SX were similar,while the delivery rate of Omron NE-C28 was low. The total delivery of each nebulizer was about 0.11μg. Statistical analysis showed that different nebulizer had no significant difference on delivered dose ,but had signifi?cant difference on delivered rate(P<0.01)and aerodynamic measurement results(P<0.05). Conclusion Different jet nebulizers for budesonide inhalation suspension have certain influence on its in vitro deposition. The suitability of the Omron NE-C28 is the best among the three kinds of nebulizers.