Hebert R L, Vick M L, King G E, Bent J P
Division of Otolaryngology, Medical College of Georgia, USA.
Otolaryngol Head Neck Surg. 2000 Mar;122(3):330-3. doi: 10.1016/S0194-5998(00)70042-8.
The treatment of patients with tympanostomy tubes (TTs) and otorrhea with medicated otic suspensions is well known, but confirmation of penetration into the middle ear is difficult. To address this question, we created an in vitro model of the human head and ear and then tested it with 5 different types of liquid exposure: tap water, soapy water, polymyxin B sulfate (Cortisporin), tobramycin and dexamethasone (TobraDex), and ciprofloxacin (Cipro) suspensions. A positive test result corresponded to liquids entering the middle ear through the TT. No positive test result was elicited with tap water (0/20), but soapy water did enter the middle ear (10/40) and was statistically significant (P = 0.0112). Without the use of slight tragal pressure, Cortisporin, TobraDex, and Cipro drops did not consistently pass through the TT (0/20, 1/25, 1/25). By placing the drops with the addition of tragal pressure, a statistically significant difference was obtained for each solution (20/20, 20/20, and 20/20, respectively [P < 0.0001]). We conclude that with a clean external auditory canal, patent TT, and no middle ear fluid, medicated otic suspensions enter the middle ear only when combined with slight tragal pressure.
使用含药耳用混悬液治疗鼓膜置管（TT）患者并发耳漏是众所周知的，但证实药物进入中耳却很困难。为解决这个问题，我们创建了一个人体头部和耳朵的体外模型，然后用5种不同类型的液体进行测试：自来水、肥皂水、硫酸多粘菌素B（可的舒）、妥布霉素和地塞米松（托百士）以及环丙沙星（西普乐）混悬液。阳性测试结果表示液体通过鼓膜置管进入中耳。自来水未得出阳性测试结果（0/20），但肥皂水确实进入了中耳（10/40），且具有统计学意义（P = 0.0112）。在不施加轻微耳屏压力的情况下，可的舒、托百士和西普乐滴耳液并不能始终通过鼓膜置管（0/20、1/25、1/25）。通过在施加耳屏压力的情况下滴注，每种溶液都获得了具有统计学意义的差异（分别为20/20、20/20和20/20 [P < 0.0001]）。我们得出结论，在外耳道清洁、鼓膜置管通畅且中耳无积液的情况下，含药耳用混悬液只有在结合轻微耳屏压力时才会进入中耳。
