COMPARISON BETWEEN THE SCINTIGRAPHIC UPTAKE AND PLASMA CLEARANCE OF 99mTc-DIETHYLENETRIAMINEPENTACETIC ACID (DTPA) FOR THE EVALUATION OF THE GLOMERULAR FILTRATION RATE IN DOGS

The scintigraphically measured percentage dose uptake of ^99mTc-DTPA by the kidneys and the plasma clearance of ^99mTc-DTPA have been reported to correlate well with inulin clearance. These two parameters were evaluated in seven dogs with known or suspected naturally occurring renal disease and compared to simultaneously measured renal inulin clearance. Correlation between inulin clearance and the ^99mTc-DTPA plasma clearance was better ( p =.0016) than the correlation between the percentage DTPA uptake by the kidney. It was concluded that measurement of ^99mTc-DTPA plasma clearance is a more accurate method to estimate global glomerular filtration rate (GFR) than the percentage kidney uptake.     

Performance Evaluation of the ADS 1000 Ventilator Using a Lung Model

A laboratory evaluation was performed to evaluate the performance characteristics of a new veterinary ventilator. The ventilator studied was configured according to manufacturer's directions and attached to a test lung via a pneumotachograph and differential pressure transducer interfaced to a pulmonary mechanics analyzer system. Constant resistance (R=10 cm H₂O/L/sec) and compliance (C=3 ml/cm H₂O) factors were maintained for all trials. The ventilator operated at the manufacturer's preprogrammed parameters. In the first trial, body weight was the only variable. In the second trial, an endotracheal tube was placed in series between the ventilator's breathing circuit and the pneumotachograph. Body weights from 1–20 kgs were evaluated. Mean values for respiratory rate (RR), minute ventilation (VE), inspiratory time (Ti), peak inspiratory pressure (PIP), and peak inspiratory flow (Fpki) displayed on the ventilator control panel; tidal volume (VT), calculated from the displayed minute volume, and identical parameters measured by the pulmonary mechanics system at each body weight, were compared using a two factor analysis of variance. Significant differences (P< 0.05) were found between mean displayed and measured values for RR, PIP, and Fpki.     

Exercise-induced pulmonary hemorrhage in the racing appaloosa horse

A retrospective survey was carried out at a Florida racetrack in 1984, to determine the prevalence of exercise-induced pulmonary hemorrhage (EIPH) in Appaloosa horses. Of 94 horses examined endoscopically between 30 and 90 minutes after racing, forty-nine (52%) were found to exhibit some degree of EIPH. There was a significantly increased prevalence of EIPH with increasing age in this population. An increased prevalence of EIPH was noted with mares and geldings as compared with stallions, but this was not statistically significant. More horses bled from the right lung than from the left, but the difference was statistically insignificant. An increased prevalence of EIPH with distance run was evident, but this was not significant when animals of the same age were examined.     

Accuracy of the thermodilution method in estimating high flow - an in vitro study

The accuracy of thermodilution for measuring flow rates of 10–40 L/min was evaluated using a commercially available thermodilution cardiac output computer in an in vitro model. Water (36.5–37.5°C) was directed through a mixing chamber via a constant flow pump. Thermodilution estimates of flow using four different volumes (10, 20, 30, 40 ml) of iced water injectate were compared to simultaneous measurements of timed samples of effluent from the mixing chamber. Injectate volume had a significant impact on the accuracy of thermodilution estimation (p < 0.05). Thermodilution overestimated measured flow when 10 and 20 ml of injectate were used to determine flow rates < 20 L/min but underestimated flow when injectate volumes of 30 and 40 ml were used, or when measured flow was > 25 L/min. The discrepancy between thermodilution flow and measured flow increased as rate of fluid flow increased.     

COMPUTED TOMOGRAPHY-GUIDED PERCUTANEOUS BIOPSY: CRITERIA FOR ACCURATE NEEDLE TIP IDENTIFICATION

Precise localization of the needle tip during CT-guided percutaneous biopsy is considered to be a key element of a successful procedure. To ensure accuracy, the true needle tip must be differentiated from a false or simulated tip which appears when the CT slice encompasses only the shaft of an angled needle. By obtaining images of an aspiration biopsy needle inserted vertically into a phantom and then incrementally tilting the gantry, the authors were able to compare the characteristic features of the true tip to the simulated tip. The true tip was abrupt and distinct and had an adjacent flame-like low density artifact. The simulated tip was indistinct and tapered, yet still produced the adjacent artifact. We concluded that the shape and distinctness of the end portion of the needle itself, rather than the attendant artifact, were the most reliable criteria for accurate needle tip identification.