Potential for Use of Portable Ultrasound Devices in Rural and Remote Settings in Australia and Other Developed Countries: A Systematic Review.

Introduction: Point of care ultrasound (POCUS) has become more common for rapid evaluation. Applications are limited by lack of training of users, difficulty maintaining ultrasound competencies, access to equipment for optimal imaging, and limitations in quality control. Such barriers exist in low-resource, underserved health care settings.

An experimental study of inner ear pathology due to NaCl on the round window.

An animal experiment was performed to evaluate structural and ultrastructural changes to the inner ear as a result of placing 3-4 crystals of reagent grade sodium chloride (NaCl) on the round window membrane. Chinchillas were sacrificed at 8 and 24 hours after treatment and the cochlear and vestibular tissues were examined by light microscopy and scanning electron microscopy. Inner ear pathology consisted of destruction of both sensory and supporting cells in the basal turn of the organ of Corti, atrophy of the stria vascularis and alterations to the otoconia and the maculae and ampullae of the vestibular system.

A morphometric study of microvascular pathology following experimental rupture of Reissner's membrane.

In a previous paper (this volume) we described a method for evaluating the cochlear microvasculature. This method was applied to the analysis of lateral wall tissue from chinchillas sacrificed 1 h, 24 h, 1 week and 3 weeks after surgical rupture of Reissner's membrane. The degree, direction, and time course of pathological changes seen in the microvessels were different for the system of stria vascularis vessels, the system of spiral ligament vessels, and the system of spiral prominence vessels.

A morphometric technique for analysis of cochlear vessels.

A computer based system was developed for morphometric analysis of the cochlear lateral wall vasculature. Variables measured were vascular density, RBC density, vessel width, aggregation density, lumen compression count, WBC count and pigment density. Vessels were divided into three systems based on the lateral wall structures that they supplied.

Effect of high intensity impulse noise on the vascular system of the chinchilla cochlea.

Changes in the vasculature of the chinchilla cochlea were quantitatively assessed 45 days after impulse noise exposure of either 155- or 160-dB peak sound pressure level. The condition of the vessels in the lateral wall and spiral lamina of each cochlea was evaluated in terms of 20 morphological parameters. Multivariate statistical analysis identified the parameters that were significantly affected by the noise exposure.

Cochlear vascular and sensory cell changes induced by elevated temperature and noise.

The vascular anatomy of the chinchilla cochlea was quantitatively analyzed and compared in animals exposed to 155- or 160-dB impulse noise at normal (37 degrees C) and elevated (40 degrees C) body temperatures. Vascular changes persisted 45 days after noise exposure in all experimental animals. Six variables were most susceptible to change in one or more of the vessels studied: 1) irregularities in the vessel lumen, 2) plasma spaces between red blood cells (RBCs) and the vessel wall, 3) columns of RBCs, 4) variability in density of RBCs, 5) pigment clumps in the stria vascularis, and 6) perivascular cells compressing the vessel lumen.

Tympanostomy tubes and otic drops.

Otic drops have been proposed as a form of prophylaxis against the otitis media which follows middle ear contamination by water in patients with tympanostomy tubes. The potential adverse effects of this form of therapy were studied in chinchillas with tympanostomy tubes; 31 chinchillas underwent bilateral tympanostomy tube insertion. Seven animals had a mixture of green dye and Cortisporin otic suspension placed in both external auditory canals 24 hours following the placement of tympanostomy tubes and were sacrificed 30 minutes later for gross examination; 3 of these animals had previous eustachian tube obstruction with Silastic sponge.