Comparison of lung tissue concentrations of nebulized ceftazidime in ventilated piglets: ultrasonic versus vibrating plate nebulizers.

OBJECTIVE

To compare the efficiency of an Aeroneb Pro vibrating plate and an Atomisor MegaHertz ultrasonic nebulizer for providing ceftazidime distal lung deposition.

DESIGN

In vitro experiments. One gram of cetazidime was nebulized in respiratory circuits and mass median aerodynamic diameter of particles generated by ultrasonic and vibrating plate nebulizers was compared using a laser velocimeter. In vivo experiments. Lung tissue concentrations and extrapulmonary depositions were measured in ten anesthetized ventilated piglets with healthy lungs that received 1 g of ceftazidime by nebulization with either an ultrasonic (n = 5), or a vibrating plate (n = 5) nebulizer.

SETTING

A two-bed Experimental Intensive Care Unit of a University School of Medicine.

INTERVENTION

Following sacrifice, 5 subpleural specimens were sampled in dependent and nondependent lung regions for measuring ceftazidime lung tissue concentrations by high-performance liquid chromatography.

MEASUREMENTS AND RESULTS

Mass median aerodynamic diameters generated by both nebulizers were similar with more than 95% of the particles between 0.5 and 5 microm. Lung tissue concentrations were 553 +/- 123 [95% confidence interval: 514-638] microg g(-1) using ultrasonic nebulizer, and 452 +/- 172 [95% confidence interval: 376-528] microg g(-1) using vibrating plate nebulizers (NS). Extrapulmonary depositions were, respectively, of 38 +/- 5% (ultrasonic) and 34 +/- 4% (vibrating plate) (NS).

CONCLUSIONS

Vibrating plate nebulizer is comparable to ultrasonic nebulizers for ceftazidime nebulization. It may represent a new attractive technology for inhaled antibiotic therapy.