Ultrasound characterization of middle ear effusion.

PURPOSE: To further enhance and assess the ability to characterize middle ear effusion (MEE) using non-invasive ultrasound technology. MATERIALS AND METHODS: This is a prospective unblinded comparison study. Fifty-six children between the ages of 6 months and 17 years scheduled to undergo bilateral myringotomy with pressure equalization tube placement were enrolled. With the child anesthetized, the probe was placed into the external ear canal after sterile water was inserted. Ultrasound recordings of middle ear contents were analyzed by computer algorithm. Middle ear fluid was collected during myringotomy and analyzed for bacterial culture and viscosity. RESULTS: Ultrasound waveforms yielded a computer algorithm interpretation of middle ear contents in 66% of ears tested. When a result was obtained, the sensitivity and specificity for successfully characterizing middle ear fluid content as either void of fluid, thick fluid (mucoid), or thin fluid (serous or purulent) were at least 94%. Mucoid effusions had higher measured viscosity values (P=.002). Viscosity measures were compared to culture result, and those with low viscosity (thin consistency) had a higher likelihood of having a positive culture (P=.048). CONCLUSION: The device sensitivity and specificity for fluid detection were 94% or greater among interpretable waveforms (66% of those tested). Although this technology provides important information of the middle ear effusion presence and characteristic, further technological improvements are needed.

In vivo evaluation of a new surfactant polymer coating mimicking the glycocalyx of endothelial cells.

The purpose of this study was to demonstrate that a proprietary surfactant polymer (SP) coating does not adversely affect the hemodynamic performance of cardiopulmonary bypass (CPB) or gas exchange in oxygenators. The new coating was applied to a CPB circuit including cannulae, reservoir, oxygenator, and blood pump implanted into 12 pigs, divided into groups with either coated or noncoated pumps. CPB flow was maintained at a fixed level of approximately 2.4 L/min for 6 hours with full heparinization. Hemodynamic data and pump performance were recorded every hour, and blood samples were taken every 2 hours. After sacrifice, the CPB circuit and major organs were macroscopically examined. There was no significant difference in the oxygen transfer rate between the two groups. The coating did not adversely affect oxygenator inlet or outlet pressures. There was no significant difference between the two groups in microthrombi seen in the oxygenators. No thromboemboli were noted in the major organs on gross or histologic examination. In conclusion, this new SP coating did not decrease gas exchange performance, and its biocompatibility evaluations revealed no differences between coated and noncoated groups under aggressive heparin use.