[Can mesh nebulizers improve prehospital aerosol therapy? An in vitro study on simulated prehospital emergency patients suffering from respiratory distress]. / Können Mesh-Vernebler die prähospitale Aerosoltherapie verbessern? Eine In-vitro-Studie an simulierten Notfallpatient*innen mit Atemnot.

BACKGROUND: Nebulizers used to treat prehospital emergency patients should provide a high output efficiency to achieve a fast onset of therapeutic drug effects while remaining unaffected by the presence of supplementary oxygen flow or the patient's breathing pattern. On the other hand, nebulizer performance is directly influenced by differences in device design, gas flow and patients' breathing patterns. Several studies from emergency departments were able to demonstrate an improvement in patient outcome when using a mesh nebulizer instead of a jet nebulizer. Data or bench studies regarding prehospital care are non-existent. OBJECTIVE: The aim of the present in vitro study was to evaluate which type of aerosol generator would best address the requirements of a prehospital adult emergency patient suffering from respiratory distress. MATERIAL AND METHODS: We evaluated the performance of a jet nebulizer (Cirrus™ 2, Intersurgical®) and two mesh nebulizers (Aerogen Solo® with USB controller, Aerogen Limited and M­Neb® mobile, NEBU-TEC International med. Produkte Eike Kern GmbH) with the possibility of portable operation in an in vitro model of a spontaneously breathing adult emergency patient. One physiological and three pathological breathing patterns (distressed breathing pattern as well as stable and acute exacerbated chronic obstructive pulmonary disease) were simulated. Nebulizer output and salbutamol lung deposition were measured at different oxygen flow rates using a face mask as the delivery interface. RESULTS: The mesh nebulizers produced a significantly higher aerosol output when compared to the jet nebulizer. The M­Neb® mobile was able to significantly exceed the output of the Aerogen Solo®. Oxygen flow had the largest influence on the output of the jet nebulizer but hardly affected the mesh nebulizers. After a nebulization time of 10 min the M­Neb® mobile also achieved the highest total salbutamol lung deposition (P < 0.001). Aerosol drug deposition was therefore mainly determined by the nebulizer's drug output per unit time. The deposition could not be improved using a spacer but was strongly influenced by the simulated emergency patients' breathing pattern. CONCLUSION: The use of mesh nebulizers might have the potential to improve the aerosol therapy of prehospital emergency patients. In general, mesh nebulizers seem to be superior to jet nebulizers regarding aerosol output per unit time and total lung deposition. The present data suggest that aerosol output and drug deposition to the collection filter in this simulated setting are closely connected and crucial for total salbutamol deposition, as the deposition could not be improved by adding a spacer. Aerosol drug deposition in simulated emergency patients' lungs is therefore mainly determined by the nebulizer's drug output per unit time. The level of oxygen flow used had the largest influence on the output of the jet nebulizer but hardly affected the output of the tested mesh nebulizers. Mesh nebulizers could therefore enable a demand-adapted oxygen therapy due to their consistent performance despite the presence of oxygen flow. A high respiratory rate was associated with a high drug deposition, which is clinically desirable in the treatment of patients in respiratory distress; however, drug underdosing must also be expected in the treatment of bradypneic patients. Further clinical studies must prove whether our findings also apply to the treatment of real prehospital emergency patients.

[Nebulization of emergency medications in the south German rescue service]. / Vernebelung von Notfallmedikamenten im süddeutschen Rettungsdienst.

BACKGROUND: In German emergency rescue services, inhalation treatment is routinely carried out by qualified health personnel. Standard operating procedures (SOP) for nebulization are neither uniform throughout Germany nor available in all federal states. Standardized recommendations with respect to which nebulizer type should be used are missing. The aerosol output as well as the drug deposition rates of jet and mesh nebulizers, however, differ considerably. Mesh devices can achieve a threefold higher lung deposition. Their use in emergency departments has also been shown to be associated with a better patient outcome when compared to jet nebulizers. OBJECTIVE: This survey was designed to evaluate the type of nebulizer used in the south German rescue services. Special attention was paid to the influence of existing SOP on the decision to perform nebulization during emergency treatment. MATERIAL AND METHODS: A total of 4800 emergency paramedics working in Baden-Württemberg, Bavaria and Rhineland-Palatinate received a questionnaire with a total of 17 questions on the implementation of drug nebulization in the daily practice. RESULTS: Despite the existence of more efficient nebulizer types, the jet nebulizer was by far the most frequently used nebulizer in the south German rescue services. The deposition rates of both the jet and mesh nebulizers were considerably overestimated by most respondents; however, 77.5% of all respondents could not give any information about the deposition rates of the mesh nebulizer. Only two thirds of all respondents carried out nebulization treatment on the basis of SOP. The implementation of SOP, however, was pivotal to the application of nebulization during emergencies. If SOP were in place,76.9% of the responders used aerosol treatment compared to 23.1% when there were none. The perceived safety when using nebulization during emergencies was also significantly higher (p = 0.013) when SOP were implemented. CONCLUSION: The exclusive use of mesh nebulizers could standardize the treatment of emergency patients in the south German rescue services. The use of mesh devices might possibly improve patient outcomes, even if clinical studies are still lacking. Nebulizer treatment differs between the federal states. A comprehensive implementation of SOP for nebulization treatment might support this process and could increase the application frequency and the perceived safety of nebulization during emergencies. A better training of paramedic personnel could improve the knowledge of aerosols as a treatment option for emergency patients and help to classify the advantages and disadvantages of the different aerosol generators available.