Tomasz J. Petelenz

Iontophoresis of dexamethasone: laboratory studies

Abstract We have demonstrated that dexamethasone sodium phosphate (DmNaP) is delivered most efficiently from the negative electrode by iontophoresis, but, under certain conditions, the delivery from the positive electrode by electroosmosis can be accomplished. The laboratory data indicate that more dexamethasone is delivered per mAmin by iontophoresis than by electroosmosis, thus the same amount of drug can be administered in a shorter time from the negative electrode. Electrodes containing a hydrogel material, which restricts bulk water transport, delivered DmNaP most efficiently from the electrode of negative polarity. When DmNaP is to be delivered in a mixture with another drug such as lidocaine, selection of the clinical treatment protocol depends on the desired therapeutic effect and on the iontophoretic electrode which is to be used. When minimization of total treatment time is not critical, switching polarity of the electrode during the treatment can be used to administer drugs of opposite polarity from a mixture. Since co-iontophoresis of different compounds is often necessary for fully effective therapy, further research to understand the mechanism of simultaneous transport of various drugs is required.

Longitudinal monitoring of patient limb loading throughout ankle fracture rehabilitation using an insole load monitoring system: a case series

Background: The purpose of this prospective, direct observational study was to evaluate limb loading in lower extremity orthopaedic trauma patients using a novel insole sensor, the Ambulatory Tibial Load Analysis System (ATLAS). Methods: Three patients from a level I trauma center, one with a trimalleolar ankle fracture, one with a distal, spiral fracture of the tibia and fibula at the same level, and one with a bimalleolar ankle fracture were observed using an insole load monitoring system to record their weight bearing during standard of care rehabilitation. No clinical decisions were made based on the limb loading data. The primary study measures were limb-loading data provided by the ATLAS and patient reported physical function as measured by the PROMIS Physical Function Computer Adapted Test. Results: The ATLAS provided 8-12 wk of continuous limb loading data, with raw loading data, duration of insole sensor and CAM walker wear, daily step count, median load per day, and periods of static and dynamic loading for three patients with varying ankle fractures. Conclusions: The findings of this case study support the use of the ATLAS sensor in evaluation of limb loading in patients with lower extremity fracture. The data suggest that the current weight bearing prescription may not be sufficient for all patients and that personalized protocols are warranted.

Development of a novel intra-abdominal pressure transducer for large scale clinical studies

Intra-abdominal pressure may be one of the few modifiable risk factors associated with developing a pelvic floor disorder. With one in eight women having surgery to correct a pelvic floor disorder in their lifetimes, intra-abdominal pressure may be a key to understanding the disease etiology and how to mitigate its occurrence and progression. Many traditional methods of intra-abdominal pressure measurement have limitations in data quality, environment of use, and patient comfort. We have modified a previously reported intravaginal pressure transducer that has been shown to overcome other intra-abdominal pressure measurement technique limitations (Coleman et al. 2012). Our modifications to the intravaginal pressure transducer make it easier to use, less costly, and more reliable than previous designs, while maintaining accuracy, integrity, and quality of data. This device has been used in over 400 participants to date as part of one of the most comprehensive studies examining the relationship between intra-abdominal pressure and pelvic floor disorders.