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Biomedical subjects

J R Pascoe

Publications and source records attributed to J R Pascoe.

At least 91 records · Page 5Linked to original sources

Efficacy of furosemide in the treatment of exercise-induced pulmonary hemorrhage in Thoroughbred racehorses.

The repeatability of endoscopic observations of exercise-induced pulmonary hemorrhage (EIPH) and the efficacy of furosemide as a prophylactic treatment of horses with EIPH were studied in Thoroughbred race horses after consecutive breezes (at or near maximum speed, approx 16 m/s). Of 56 horses examined greater than or equal to 2 times, 21 (38%) had identical EIPH scores, whereas 26 (46%) and 9 (16%) had scores that differed by greater than or equal to 1 grade. In 56 nontreated horses, there was good agreement between 2 consecutive observations (K = 0.59, Z = 4.54, P less than 0.001). Similar comparisons after placebo (saline solution) treatment of 21 horses yielded fair to good agreement, whereas poorer agreement was seen after furosemide treatment of 23 horses. Comparison of average and maximum EIPH scores of 44 horses with a minimum of 4 observations (2 nontreated, 1 saline-treated, and 1 furosemide-treated) indicated that although furosemide did not stop EIPH, it did reduce the EIPH score in 28 (64%) horses.

Animals↗

Topographic distribution of pulmonary ventilation and perfusion in the horse.

The regional distribution of ventilation to perfusion ratios (VA/Q) in the lungs of 8 healthy standing Thoroughbred geldings (4.4 +/- 1.5 years, 465.7 +/- 46.6 kg) was studied, using steady-state inhalation and IV infusion of the radioactive gas krypton-81m. The VA/Q was uniformly distributed within a vertical lung strip centered over the 9th rib on the right side. Ventilation per unit of alveolar volume (V/VA) assessed from the clearance of inhaled radioactive gas in 5 horses increased from 0.49 +/- 0.13 (arbitrary units) in nondependent lung zones to 1.45 +/- 0.16 in dependent lung zones. Seemingly, a vertical gradient of pulmonary ventilation exists in the horse that is matched by a similar gradient of perfusion.

Animals↗

Surgical management of uterine torsion in the mare: a review of 26 cases.

Uterine torsion was diagnosed in 26 mares of various breeds. The mean duration of gestation was 9.6 months. The most common clinical history was intermittent unresponsive colic of varying duration. Diagnosis of uterine torsion was confirmed by rectal palpation, and surgical correction was achieved in most cases by standing flank laparotomy and manual repositioning of the gravid uterus. Recumbent laparotomy was used only if the mare was intractable, the uterus was ruptured, or hysterotomy was indicated. Of 20 foals determined to be alive during surgery, 14 (70%) were subsequently born alive.

Animals↗

Torsion of the spermatic cord in a horse.

A 360-degree torsion of the left spermatic cord was diagnosed in a 2 1/2-year-old Quarter Horse colt. Clinical signs included abdominal discomfort, with slight elevations in heart and respiratory rates. The scrotum on the left side was moist and edematous. The left testicle was enlarged, firm, and retracted slightly toward the abdominal cavity. The colt resented palpation of the testicle. On rectal palpation, the left vaginal ring and the structures passing through the ring were edematous and painful to pressure. Surgical correction was achieved by emasculation. The tail of the epididymis and an elongated portion of the body of the epididymis were attached to the left testicle by an unduly long mesorchium. The caudal ligament of the epididymis and the proper ligament of the testis were elongated. These anatomic variations may have predisposed to torsion of the spermatic cord.

Animals↗

Exercise-induced pulmonary hemorrhage in racing thoroughbreds: a preliminary study.

Of 235 Thoroughbred racehorses examined with a flexible fiberoptic endoscope within 2 hours of racing to determine the frequency of exercise-induced pulmonary hemorrhage (EIPH), 103 (43.8%) had various degrees of hemorrhage in the tracheal lumen. Two of these horses (0.8%) subsequently had blood flow from the nostrils. Blood seemed to originate from the lung. Statistical analysis of frequency data for 191 horses which finished in 1st, 2nd, and 3rd places did not show any relationship between EIPH and horse's age, sex, or finishing position. However, a trend toward an increased frequency of EIPH with age was shown, by a greater proportion of horses 5 years and older having EIPH. This trend is thought to reflect the chronicity of the pulmonary lesions and an inability of the lung to repair damaged regions while training and racing continued. The efficacy of furosemide for the treatment of EIPH was questioned, since 30 of 56 furosemide-treated horses which were examined had evidence of pulmonary hemorrhage. Nineteen (8%) horses had visible functional abnormalities of the upper respiratory tract.

Age Factors↗

A technique for management of traumatic rupture of the equine suspensory apparatus.

Problems involving the management of acute traumatic rupture of the equine suspensory apparatus include loss of blood flow to the foot, proper immobilization, and pressure sores from casts. A technique utilizing a board splinting device attached to the affected limb at the toe and subsequent corrective shoe support provides immobilization, prevents dropping of the fetlock, can be applied to the standing animal, and allows frequent changing of the bandages, if necessary.

Animals↗

The effect of doxapram-induced hyperventilation on respiratory mechanics in horses.

To investigate the influence of increased respiratory frequency on respiratory mechanics in the horse, measurements were made in two groups of seven tracheostomized horses before and after the administration of doxapram. The horses in group I had normal base line values for respiratory mechanics, whereas the horses in group II had significantly lower values of dynamic compliance (Cdyn), higher respiratory resistance (R), and a higher total change in pleural pressure (delta P). The administration of 0.3 mg kg-1 doxapram intravenously resulted in a significant increase in respiratory frequency (fR), R, delta P, tidal volume (VT), and peak to peak respiratory flow (V), and a decrease in Cdyn in both groups of horses. The group II horses had significantly greater increases in R and delta P than the horses in group I.

Animals↗

Use of pelvic flexure biopsies to predict survival after large colon torsion in horses.

OBJECTIVE: To determine if morphologic evaluation of intraoperative biopsies of the large colon could be used to accurately predict outcome in horses with large colon torsion. STUDY DESIGN: Clinical study. ANIMALS: Fifty-four horses with large colon torsion. METHODS: A full-thickness biopsy was collected from the pelvic flexure of the ascending colon after correction of naturally occurring colonic torsion. Morphologic changes were evaluated and graded for interstitial tissue to crypt ratio (I:C ratio), percentage loss of superficial and glandular epithelium, and the degree of hemorrhage and edema. These variables were then used to predict survival. RESULTS: Morphologic variables could be used to correctly predict survival or death in 51 horses (P < .0001). This corresponded to a sensitivity of 95.1% (82.2%-99.2%; 95% CI) and a specificity of 92.3% (62.0%-99.6%; 95% CI). Of 6 horses that had colonic resection, 5 survived; an accurate prediction of outcome based on morphologic criteria was made for each horse. CONCLUSIONS: Interpretation of changes in colonic morphology can be used to accurately predict postoperative survival in horses with large colon torsion. CLINICAL RELEVANCE: Use of frozen colonic tissue sections is a rapid, reliable, and relatively inexpensive method for assessing morphologic damage associated with large colon torsion during surgery. Intraoperative evaluation of pelvic flexure biopsies can aid in the prediction of survival and guide surgical judgment as to the need for colonic resection.

Animals↗

A potential technique error in stapled side-to-side anastomosis of the small intestine of the horse.

Anastomotic leakage was noted to occur at the junction of the staple lines used to create the stoma during small intestine side-to-side anastomosis. The anastomosis was performed in a clinical equine patient by joining the lateral surfaces of the intestinal segments using a gastrointestinal anastomosis stapling instrument (GIA). The cause of this problem was investigated by performing six anastomoses in the jejunum of a single anesthetized adult horse using the GIA; three anastomoses were created by joining the antimesenteric edges of the bowel segments and three anastomoses were created by joining the lateral surfaces of the bowel segments. Bowel segments were then dissected to examine the stoma and the integrity of the staple lines. No defects were detected in anastomoses performed by joining the antimesenteric edges. Anastomoses performed by joining the lateral surfaces all had a defect at the junction of the double rows of staples used to create the stoma. Such defects would have allowed leakage of fluid and/or ingesta at the anastomotic site.

Anastomosis, Surgical↗

Antimicrobial susceptibility of microorganisms isolated from equine orthopedic patients.

Positive cultures were obtained from 60 equine orthopedic cases during a 12 year period (1974-1985). These cases consisted of 34 long or cuboidal bone fractures, 13 arthrotomy/arthroscopy procedures for removal or internal fixation of a fracture, 7 proximal splint bone fractures, and 6 facial or mandibular fractures. Excluding the 13 arthrotomies, only 10 (21%) of the 47 were open fractures. Multiple organisms were isolated from 36 cases (20 long or cuboidal bone fractures, 7 splint bone fractures, 5 mandibular fractures, and 4 intra-articular fractures). Of the 142 isolates, 35 (24%) were members of the family Enterobacteriaceae, 33 (23%) Streptococcus spp., and 25 (18%) Staphylococcus spp. with the majority being coagulase positive (65%). Other organisms isolated were Pseudomonas spp. (16, 11%), obligate anaerobes (11, 7%), and Actinobacillus spp. (7, 5%). the remaining 10% consisted of Pasteurella spp., Bacillus spp., Corynebacterium spp., Micrococcus spp., and Actinomyces spp. When comparing results between two time periods (1974-1979 and 1980-1985) there was an increase in the percentage of coagulase positive staphylococci isolates resistant to all antimicrobics tested except oxacillin and amikacin, and Escherichia coli isolates were resistant to all but amikacin. For Pseudomonas spp., resistance to gentamicin increased in the second time period (1980-1986). During the initial time period (1974-1979) culture tests for obligate anerobes were not conducted until 1975. No anerobes were cultured during those initial 5 years; however, one third of those isolated after 1980 were resistant to penicillin and ampicillin.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Surgical management of proximal splint bone fractures in the horse.

Fractures of Metacarpal and Metatarsal II and IV (the splint bones) were treated in 283 horses over an 11 year period. In 21 cases the proximal portion of the fractured bone was stabilized with metallic implants. One or more cortical bone screws were used in 11 horses, and bone plates were applied in 11 horses. One horse received both treatments. Complications of screw fixation included bone failure, implant failure, radiographic lucency around the screws, and proliferative new bone at the ostectomy site. Only two of the horses treated with screw fixation returned to their intended use. Complications of plate fixation included partial fixation failure (backing out of screws), wound drainage, and proliferative bony response around the plate. Six of the 11 horses treated by plate fixation returned to their intended use. The authors recommend consideration of plate fixation techniques for repair of fractures in the proximal third of the splint bone.

Animals↗

Survival after small intestine resection and anastomosis in horses.

The authors examined factors influencing survival in 140 horses that recovered from anesthesia after small intestinal resection between 1968 and 1986, using Kaplan-Meier estimated survival curves and the Cox proportional hazards regression model. Seventy-two horses (51%) died during the initial postoperative period, 19 horses (14%) died after discharge from the hospital, 33 horses (24%) were alive, and 16 horses (11%) were classified as censored. Mean age at surgery was 8 years. Horses 15 years of age or older, Arabians and Stallions, were overrepresented in the hospital population. The most common reason for resection was strangulation of bowel through a mesenteric rent. The mean and 50% median survival times were 1540 and 27 days, respectively. Horses admitted after January 1, 1980, had a significantly longer survival than those admitted before that time. Survival was longer after anastomosis of two small intestinal segments than after anastomosis of a small intestinal segment to the cecum; however, the length of bowel resected and the method of anastomosis had no demonstrable influence on survival. Of the variables studied, the heart rates at presentation and 24 hours after surgery were the most accurate predictors of survival.

Age Factors↗

Femoral capital physeal fractures in 25 foals.

The medical records of 25 horses 1 year of age or younger affected with femoral head and neck fractures during an 18 year period were reviewed. Each fracture involved the capital physis. The foals were 11 days to 12 months of age (mean, 5 months). No femoral capital physeal fractures occurred in horses older than 1 year of age during the same period. The history in each case included acute onset of severe unilateral hindlimb lameness, 3 hours to 2 months (mean, 12 days) before presentation. Injuries observed were violent falls, struggles, and kicks. Crepitation, swelling, pain with manipulation or palpation or both, and apparent fracture fragment displacement were inconsistently noted. Tentative clinical diagnoses were confirmed by radiography in 24 foals and by necropsy alone in one foal. Twenty-one foals were euthanatized due to poor prognosis. One foal sent home for stall rest was lost to follow-up. Surgical repair was attempted in three foals. Two fractures were repaired with multiple intramedullary pins and the foals were euthanatized within 2 weeks due to surgical failure and, in one case, contralateral limb breakdown. The third fracture was repaired with a compressing screw and plate device; the animal was pasture sound at month 20.

Animals↗

Evaluation of an interfragmentary compression system for the repair of equine femoral capital physeal fractures.

Femoral neck and proximal epiphyseal lengths were measured in 37 femurs from 19 cadaver foals that were 1 day to 12 months old to determine the applicability of a human interfragmentary compression system to equine femoral capital physeal fractures. Because components of the implant system are available only in fixed sizes, its use was possible in foals older than 5 weeks of age, but not in younger foals. The 135 degree angle plate conformed best to the equine femur. Femoral capital physeal fractures were created surgically and repaired with the implant system in three foals. Fracture stability was evident clinically and radiographically in all three foals until euthanasia at month 3. At necropsy, the treated femurs were 4, 8, and 27 mm shorter than their mates. Epiphyseal viability was verified in all three foals by tetracycline deposition and new appositional bone growth comparable with that in the contralateral control epiphyses. The treated capital physis was open but reduced in thickness in one foal, disorganized in one foal, and closed in one foal. Fixation by compression with the implant system resulted in stability sufficient for fracture healing and maintenance of epiphyseal viability, although it was associated with reduced longitudinal femoral growth.

Animals↗

Effects of left recurrent laryngeal neurectomy, prosthetic laryngoplasty, and subtotal arytenoidectomy on upper airway pressure during maximal exertion.

Upper airway pressure was measured with a nasotracheal catheter system and a portable pressure transducer in 10 normal horses during maximal exercise before and after left recurrent laryngeal neurectomy. Measurements were repeated 16 weeks after prosthetic laryngoplasty (5 horses) or subtotal arytenoidectomy (5 horses). During maximal exertion, prosthetic laryngoplasty was more effective than subtotal arytenoidectomy in reversing the increases in upper airway pressure that followed left recurrent laryngeal neurectomy.

Animals↗