Taylor R H, Lerman J, Chambers C, Dolovich M
Department of Anaesthesia, Hospital for Sick Children, University of Toronto, Canada.
Chest. 1993 Mar;103(3):920-4. doi: 10.1378/chest.103.3.920.
An experimental in vitro model was used to determine the effects of intraluminal catheter diameter and length on the delivered dose and particle-size characteristics of salbutamol (albuterol) aerosol delivered by metered dose inhaler (MDI) (Ventolin, 100 micrograms per puff). The dose of aerosolized drug that exited a 16-cm-long tracheal tube with an inner diameter (ID) of 6 mm was compared with that from 4 catheters of differing diameters and lengths that were inserted individually into the tracheal tube. The salbutamol MDI canister was actuated ten times into each delivery system, and the effluent aerosol was trapped onto a filter. The filtrate was dissolved in methanol, and the salbutamol concentration was determined using high-performance liquid chromatography. For the 3 22-cm-long catheters, the delivered dose (mean +/- SD) of salbutamol per actuation for the 22-standard wire gauge (SWG) catheter was 97.5 +/- 3.9 micrograms, which was similar to that for the 19-SWG catheter (102.3 +/- 2.5 micrograms) but was significantly less than that for the 14-SWG catheter (108.2 +/- 4.2 micrograms) (p < 0.05). These delivered doses exceeded those of the 6.0-mm-ID tracheal tube alone (2.33 +/- 0.76 micrograms) and the 13-cm-long 19-SWG catheter (2.17 +/- 0.29 micrograms) (p < 0.001). In a second experiment using a cascade impactor, the distribution of aerosol particle diameters that exited the 6-mm-ID tracheal tube was compared with that exiting a 13-cm-long 19-SWG catheter that extended halfway down the tracheal tube and with that exiting a 22-cm-long 19-SWG catheter inserted into the distal end of the 6-mm-ID tracheal tube. The mass median aerodynamic diameter (mean +/- SD) of the salbutamol aerosols delivered through both the 6.0-mm-ID tracheal tube (1.1 +/- 0.1 microns) and that of the 13-cm-long 19-SWG catheter (1.2 +/- 0.2 microns) were significantly less than that delivered through the 22-cm-long 19-SWG catheter (2.0 +/- 0.1 microns) (p < 0.05). The authors conclude that delivery of respirable aerosol can occur through narrow catheters that function as extended nozzles for MDIs. Optimal dosing will be obtained when the catheter extends the full length of the tracheal tube.
采用体外实验模型，以确定管腔内导管直径和长度对通过定量吸入器（MDI）（万托林，每喷100微克）递送的沙丁胺醇（舒喘灵）气雾剂递送剂量和粒径特征的影响。将内径（ID）为6毫米、长16厘米的气管导管喷出的雾化药物剂量，与分别插入气管导管的4根不同直径和长度的导管喷出的药物剂量进行比较。将沙丁胺醇MDI药罐向每个输送系统启动10次，流出的气雾剂被捕集在滤器上。将滤液溶于甲醇，采用高效液相色谱法测定沙丁胺醇浓度。对于3根22厘米长的导管，22号标准线规（SWG）导管每次启动时沙丁胺醇的递送剂量（平均值±标准差）为97.5±3.9微克，与19号SWG导管（102.3±2.5微克）相似，但显著低于14号SWG导管（108.2±4.2微克）（p<0.05）。这些递送剂量超过了单独使用内径6.0毫米的气管导管（2.33±0.76微克）和13厘米长的19号SWG导管（2.17±0.29微克）的剂量（p<0.001）。在使用级联撞击器的第二项实验中，比较了内径6毫米的气管导管喷出的气溶胶粒径分布，与延伸至气管导管一半长度的13厘米长19号SWG导管喷出的粒径分布，以及插入内径6毫米气管导管远端的22厘米长19号SWG导管喷出的粒径分布。通过内径6.0毫米的气管导管（1.1±0.1微米）和13厘米长的19号SWG导管（1.2±0.2微米）递送的沙丁胺醇气雾剂的质量中值空气动力学直径（平均值±标准差），显著小于通过22厘米长的19号SWG导管（2.0±0.1微米）递送的直径（p<0.05）。作者得出结论，可吸入气雾剂可通过作为MDI延长喷嘴的细导管递送。当导管延伸至气管导管全长时，可获得最佳给药剂量。
