Rebecca S. Syring

Severe blunt trauma in dogs: 235 cases (1997–2003)

Objective – To evaluate population characteristics, injuries, emergency diagnostic testing, and outcome of dogs with blunt trauma requiring intensive care in an urban hospital. Design – Retrospective study 1997–2003. Setting – All data obtained from the University of Pennsylvania – Matthew J. Ryan Veterinary Hospital. Animals – Dogs admitted to the intensive care unit for treatment following blunt trauma. Interventions – None. Measurements and Main results – Of the 235 dogs that met inclusion criteria, 206 (88%) survived and 29 (12%) did not survive. Blunt vehicular trauma accounted for 91.1% of cases. Mild hyperglycemia and hyperlactatemia was common in both survivors and nonsurvivors. The chest was the most common region traumatized and the prevalence of polytrauma was 72.3%. Initial weight, vital signs, PCV, total plasma protein, BUN, glucose, lactate, acid-base status, and electrolytes did not differ between survivors and nonsurvivors. Nonsurvivors were significantly more likely to have had head trauma (P=0.008), cranium fractures (P<0.001), recumbency at admission (P<0.001), development of hematochezia (P<0.001), clinical suspicion of acute respiratory distress syndrome (P<0.001), disseminated intravascular coagulation (P<0.001), multiorgan dysfunction syndrome (P<0.001), development of pneumonia (P<0.001), positive-pressure ventilation (P<0.001), vasopressor use (P<0.001), and cardiopulmonary arrest (P<0.001). Conclusions – Outcome of severe blunt trauma in dogs treated with intensive care is very good. Despite the high survival rate, several features associated with poor outcome were identified. Neither admission lactate nor glucose was able to predict outcome.OBJECTIVE To evaluate population characteristics, injuries, emergency diagnostic testing, and outcome of dogs with blunt trauma requiring intensive care in an urban hospital. DESIGN Retrospective study 1997-2003. SETTING All data obtained from the University of Pennsylvania - Matthew J. Ryan Veterinary Hospital. ANIMALS Dogs admitted to the intensive care unit for treatment following blunt trauma. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Of the 235 dogs that met inclusion criteria, 206 (88%) survived and 29 (12%) did not survive. Blunt vehicular trauma accounted for 91.1% of cases. Mild hyperglycemia and hyperlactatemia was common in both survivors and nonsurvivors. The chest was the most common region traumatized and the prevalence of polytrauma was 72.3%. Initial weight, vital signs, PCV, total plasma protein, BUN, glucose, lactate, acid-base status, and electrolytes did not differ between survivors and nonsurvivors. Nonsurvivors were significantly more likely to have had head trauma (P=0.008), cranium fractures (P<0.001), recumbency at admission (P<0.001), development of hematochezia (P<0.001), clinical suspicion of acute respiratory distress syndrome (P<0.001), disseminated intravascular coagulation (P<0.001), multiorgan dysfunction syndrome (P<0.001), development of pneumonia (P<0.001), positive-pressure ventilation (P<0.001), vasopressor use (P<0.001), and cardiopulmonary arrest (P<0.001). CONCLUSIONS Outcome of severe blunt trauma in dogs treated with intensive care is very good. Despite the high survival rate, several features associated with poor outcome were identified. Neither admission lactate nor glucose was able to predict outcome.

Spatial and temporal heterogeneity of ventilator-associated lung injury after surfactant depletion

Volutrauma and atelectrauma have been proposed as mechanisms of ventilator-associated lung injury, but few studies have compared their relative importance in mediating lung injury. The objective of our study was to compare the injury produced by stretch (volutrauma) vs. cyclical recruitment (atelectrauma) after surfactant depletion. In saline-lavaged rabbits, we used high tidal volume, low respiratory rate, and low positive end-expiratory pressure to produce stretch injury in nondependent lung regions and cyclical recruitment in dependent lung regions. Tidal changes in shunt fraction were assessed by measuring arterial Po(2) oscillations. After ventilating for times ranging from 0 to 6 h, lungs were excised, sectioned gravitationally, and assessed for regional injury by evaluation of edema formation, chemokine expression, upregulation of inflammatory enzyme activity, and alveolar neutrophil accumulation. Edema formation, lung tissue interleukin-8 expression, and alveolar neutrophil accumulation progressed more rapidly in dependent lung regions, whereas macrophage chemotactic protein-1 expression progressed more rapidly in nondependent lung regions. Temporal and regional heterogeneity of lung injury were substantial. In this surfactant depletion model of acute lung injury, cyclical recruitment produced more injury than stretch.

Evaluation of plasma lactate concentration and base excess at the time of hospital admission as predictors of gastric necrosis and outcome and correlation between those variables in dogs with gastric dilatation-volvulus: 78 cases (2004-2009)

OBJECTIVE To determine the correlation between plasma lactate concentration and base excess at the time of hospital admission and evaluate each variable as a predictor of gastric necrosis or outcome in dogs with gastric dilatation-volvulus (GDV). DESIGN Retrospective case series. ANIMALS 78 dogs. PROCEDURES For each dog, various data, including plasma lactate concentration and base excess at the time of hospital admission, surgical or necropsy findings, and outcome, were collected from medical records. RESULTS Gastric necrosis was identified in 12 dogs at the time of surgery and in 4 dogs at necropsy. Sixty-five (83%) dogs survived to hospital discharge, whereas 13 (17%) dogs died or were euthanized. Of the 65 survivors and 8 nonsurvivors that underwent surgery, gastric necrosis was detected in 8 and 4 dogs, respectively. Via receiver operating characteristic curve analysis, an initial plasma lactate concentration cutoff of 7.4 mmol/L was 82% accurate for predicting gastric necrosis (sensitivity, 50%; specificity, 88%) and 88% accurate for predicting outcome (sensitivity, 75%; specificity, 89%). Among all dogs, the correlation between initial plasma lactate concentration and base excess was significant, although base excess was a poor discriminator for predicting gastric necrosis or outcome (area under the receiver operating characteristic curve, 0.571 and 0.565, respectively). CONCLUSIONS AND CLINICAL RELEVANCE In dogs with GDV, plasma lactate concentration at the time of hospital admission was a good predictor of gastric necrosis and outcome. However, despite the correlation between initial base excess and plasma lactate concentration, base excess should not be used for prediction of gastric necrosis or outcome in those patients.

The Implications of Arterial Po2 Oscillations for Conventional Arterial Blood Gas Analysis

In a surfactant-depletion model of lung injury, tidal recruitment of atelectasis and changes in shunt fraction lead to large Pao2 oscillations. We investigated the effect of these oscillations on conventional arterial blood gas (ABG) results using different sampling techniques in ventilated rabbits. In each rabbit, 5 different ventilator settings were studied, 2 before saline lavage injury and 3 after lavage injury. Ventilator settings were altered according to 5 different goals for the amplitude and mean value of brachiocephalic Pao2 oscillations, as guided by a fast responding intraarterial probe. ABG collection was timed to obtain the sample at the peak or trough of the Pao2 oscillations, or over several respiratory cycles. Before lung injury, oscillations were small and sample timing did not influence Pao2. After saline lavage, when Po2 fluctuations measured by the indwelling arterial Po2 probe confirmed tidal recruitment, Pao2 by ABG was significantly higher at peak (295 ± 130 mm Hg) compared with trough (74 ± 15 mm Hg) or mean (125 ± 75 mm Hg). In early, mild lung injury after saline lavage, Pao2 can vary markedly during the respiratory cycle. When atelectasis is recruited with each breath, interpretation of changes in shunt fraction, based on conventional ABG analysis, should account for potentially large respiratory variations in arterial Po2.

Pneumomediastinum in cats: 45 cases (2000-2010).

Objective To characterize the incidence, etiology, presenting complaint, clinical course, and outcome of cats with pneumomediastinum. Design Retrospective study from the period of January 1st, 2000 to December 31st, 2010. Setting University teaching hospital. Animals Forty-five cats with a radiographic diagnosis of pneumomediastinum. Interventions None. Measurements and Main Results Medical and radiographic records were reviewed to identify cats with a radiographic diagnosis of pneumomediastinum. Clinical data were retrieved, including signalment, history, presenting clinical signs, diagnostic test results, treatment, complications, and survival to discharge. In 31 of 45 (69%) cats the pneumomediastinum was secondary to an obvious inciting cause. General anesthesia with endotracheal intubation and positive pressure ventilation was the most common cause in 17 of 45 (38%) cases. This was followed by trauma in 12 of 45 (27%) cats, and tracheal foreign bodies in 2 of 45 (4%) cats. Spontaneous pneumomediastinum (unknown underlying cause) was diagnosed in 14 of 45 (31%) of cases. Onset of clinical signs and diagnosis of spontaneous pneumomediastinum was preceded by emesis in 6 of 14 cats. Common presenting signs were tachypnea seen in 27 of 45 (60%) cats, increased respiratory effort in 26 of 45 (58%) cats, and subcutaneous emphysema in 30 of 45 (66%) cats. Concurrent pneumothorax was identified in 21 of 45 (47%) cats, pleural effusion in 10 of 45 (22%), and pneumoretroperitoneum in 21 of 45 (47%). The mainstay of treatment was supportive care and treatment of the underlying disease process. The prognosis for recovery was good, with 87% survival until hospital discharge. Conclusions Pneumomediastinum in cats is an infrequently diagnosed condition. It is often secondary to an event such as general anesthesia with endotracheal intubation and positive pressure ventilation but less frequently may occur spontaneously. The prognosis is good with appropriate supportive care.OBJECTIVE To characterize the incidence, etiology, presenting complaint, clinical course, and outcome of cats with pneumomediastinum. DESIGN Retrospective study from the period of January 1st, 2000 to December 31st, 2010. SETTING University teaching hospital. ANIMALS Forty-five cats with a radiographic diagnosis of pneumomediastinum. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Medical and radiographic records were reviewed to identify cats with a radiographic diagnosis of pneumomediastinum. Clinical data were retrieved, including signalment, history, presenting clinical signs, diagnostic test results, treatment, complications, and survival to discharge. In 31 of 45 (69%) cats the pneumomediastinum was secondary to an obvious inciting cause. General anesthesia with endotracheal intubation and positive pressure ventilation was the most common cause in 17 of 45 (38%) cases. This was followed by trauma in 12 of 45 (27%) cats, and tracheal foreign bodies in 2 of 45 (4%) cats. Spontaneous pneumomediastinum (unknown underlying cause) was diagnosed in 14 of 45 (31%) of cases. Onset of clinical signs and diagnosis of spontaneous pneumomediastinum was preceded by emesis in 6 of 14 cats. Common presenting signs were tachypnea seen in 27 of 45 (60%) cats, increased respiratory effort in 26 of 45 (58%) cats, and subcutaneous emphysema in 30 of 45 (66%) cats. Concurrent pneumothorax was identified in 21 of 45 (47%) cats, pleural effusion in 10 of 45 (22%), and pneumoretroperitoneum in 21 of 45 (47%). The mainstay of treatment was supportive care and treatment of the underlying disease process. The prognosis for recovery was good, with 87% survival until hospital discharge. CONCLUSIONS Pneumomediastinum in cats is an infrequently diagnosed condition. It is often secondary to an event such as general anesthesia with endotracheal intubation and positive pressure ventilation but less frequently may occur spontaneously. The prognosis is good with appropriate supportive care.

Association of holidays, full moon, Friday the 13th, day of week, time of day, day of week, and time of year on case distribution in an urban referral small animal emergency clinic

OBJECTIVE To interrogate the association of variables: day of week, time of day, day of the year (major holidays, Friday the 13th, and the full moon), and month of year with the caseload of an urban academic emergency service. DESIGN Retrospective study. SETTING Urban small animal teaching hospital emergency clinic. ANIMALS Cats and dogs that were presented to the emergency clinic. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS The hospital computer database was searched for all visits to the Emergency Service of the Mathew J. Ryan Veterinary Hospital of the University of Pennsylvania from January 1, 1987 through December 31, 2002. Variables included in the electronic data were date of admission, time of day of admission, species (dog or cat), hospital service the case was transferred to for ongoing care and whether the case was discharged directly from the emergency service. The association of caseload with day of week, time of day, day of the year (major holidays, Friday the 13th, and the full moon), and month of year was described and statistically evaluated. Saturdays and Sundays were the busiest days of the week and significantly increased caseload was noted for the majority of holidays (except Easter Day and Thanksgiving Day) with Memorial Day being the busiest. Midweek evenings as well as Saturday and Sunday afternoons were the busiest periods of the day. There was no association with caseload and Halloween, the full moon, or Friday the 13th. CONCLUSIONS The busiest times were midweek evenings, Saturday and Sunday afternoons, and most major holidays.

Linear versus non-linear gastrointestinal foreign bodies in 499 dogs: clinical presentation, management and short-term outcome.

OBJECTIVES To compare clinical signs, clinicopathological abnormalities, imaging findings and outcome of dogs with linear and non-linear foreign bodies in the gastrointestinal tract. METHODS Retrospective review of case records of dogs with a confirmed diagnosis of gastrointestinal foreign body. Signalment, history, clinical signs, clinicopathological data, diagnostic imaging studies, surgical and endoscopic procedures, hospital stay, costs and outcome were compared between groups. RESULTS A total of 176 dogs had linear and 323 had non-linear foreign bodies. Dogs with a linear foreign body were more likely to have a history of vomiting, anorexia, lethargy and pain on abdominal palpation. They were also more likely to have the foreign body anchored in the stomach and continuing into the small intestine, experience intestinal necrosis, perforation and peritonitis, and require intestinal resection and anastamosis. The duration of hospitalisation was longer for dogs with linear foreign body (3 versus 2 days), and the cost of treatment was 10% higher. However, in both groups, 96% of dogs survived to hospital discharge. CLINICAL SIGNIFICANCE Dogs with a linear foreign body had more severe clinical signs and gastrointestinal pathology, and an increased duration of hospitalisation and cost of care. However, overall survival rates were not different in dogs with linear and non-linear foreign bodies.

Manual of Trauma Management in the Dog and Cat: Drobatz/Manual of Trauma Management in the Dog and Cat

PREFACE. ACKNOWLEDGMENTS. CONTRIBUTOR LIST. 1. GLOBAL APPROACH TO THE TRAUMA PATIENT (Kenneth J. Drobatz). 2. TRIAGE AND PRIMARY SURVEY (Matthew W. Beal). 3. SHOCK IN THE TRAUMA PATIENT (Rebecca S. Syring). 4. MONITORING OF THE TRAUMA PATIENT (Dana L. Clarke and Andrew J. Brown). 5. ANESTHESIA AND ANALGESIA FOR THE TRAUMA PATIENT (Benjamin M. Brainard and Lindsey Culp-Snyder). 6. TRAUMA ASSOCIATED THORACIC INJURY (Matthew W. Beal). 7. TRAUMATIC BRAIN INJURY (Rebecca Syring). 8. TRAUMA ASSOCIATED PERIPHERAL NERVE INJURY (Jessica Snyder). 9. TRAUMATIC SPINAL INJURY (Daniel Fletcher). 10. URINARY TRACT TRAUMA (Merilee F. Costello). 11. TRAUMA ASSOCIATED ABDOMINAL PARENCHYMAL ORGAN INJURY (Andrew J. Brown, Charles S. McBrien, and Stephen J. Mehler). 12. TRAUMA ASSOCIATED BILIARY TRACT INJURY (Phillip Mayhew). 13. TRAUMA ASSOCIATED BODY WALL AND TORSO INJURY (Phillip Mayhew and William Culp). 14. TRAUMA ASSOCIATED GASTROINTESTINAL INJURY (Phillip Mayhew and William Culp). 15. TRAUMA ASSOCIATED OCULAR INJURY (Deborah C. Mandell). 16. TRAUMA-ASSOCIATED MUSCULOSKELETAL INJURY TO THE HEAD (Alexander M. Reiter and John R. Lewis). 17. TRAUMA-ASSOCIATED SOFT TISSUE INJURY TO THE HEAD AND NECK (John R. Lewis and Alexander M. Reiter). 18. TRAUMA ASSOCIATED MUSCULOSKELETAL INJURY TO THE APPENDICULAR SKELETON (Stephen J. Mehler). 19. TRAUMA ASSOCIATED MUSCULOSKELETAL INJURY TO THE PELVIS, SACRUM AND TAIL (Lauren May and Stephen J. Mehler). 20. BITE WOUND TRAUMA (David Holt). 21. TRAUMA ASSOCIATED AURAL INJURY (William Culp and Phillip Mayhew). INDEX.

The effect of prazosin on outcome in feline urethral obstruction

OBJECTIVE To determine whether prazosin administration following urethral obstruction (UO) reduces the risk for recurrent urethral obstruction (rUO) or lower urinary tract signs, and to document adverse effects associated with prazosin use in cats. DESIGN Double-blinded, prospective, interventional study. SETTING University teaching hospital. ANIMALS A population of 47 consecutive male cats with UO not associated with urinary tract calculi >2 mm in diameter. INTERVENTIONS Cats were randomized to receive either prazosin (0.25 mg/cat PO q 12 h, n = 27) or placebo (n = 20) for 1 month following UO. MEASUREMENTS AND MAIN RESULTS Cats were monitored for rUO, severity of lower urinary tract signs, and medication adverse effects during hospitalization and through weekly conversations with the owner during the 1- month study period and once more at 6 months following discharge. There was no difference in the rUO rate among cats that received prazosin or placebo prior to hospital discharge (2/26 (7%) versus 1/19 (5%), P = 1.00), during the 1- month medication period (4/26 (15%) versus 3/18 (17%), P = 0.776), or at 6 months following treatment for UO (7/19 (37%) versus 4/13 (31%), P = 0.811). There was no difference in the severity of lower urinary tract signs reported by the owners at the 1-, 2-, 3-, or 4-week follow-up periods among the cats in either group (P = 0.62, 0.68, 0.33, 1.00, respectively). Reported adverse effects from prazosin administration included lethargy, ptyalism, diarrhea, anorexia, and malodorous stool. CONCLUSIONS Although our study results failed to find a difference in the incidence of rUO and severity of lower urinary tract signs among cats receiving prazosin and those receiving placebo, these study results should be interpreted cautiously as our study was underpowered to identify such differences. Larger placebo-controlled, prospective studies are needed to determine the clinical utility of prazosin in prevention of rUO.Objective To determine whether prazosin administration following urethral obstruction (UO) reduces the risk for recurrent urethral obstruction (rUO) or lower urinary tract signs, and to document adverse effects associated with prazosin use in cats. Design Double-blinded, prospective, interventional study. Setting University teaching hospital. Animals A population of 47 consecutive male cats with UO not associated with urinary tract calculi >2 mm in diameter. Interventions Cats were randomized to receive either prazosin (0.25 mg/cat PO q 12 h, n = 27) or placebo (n = 20) for 1 month following UO. Measurements and Main Results Cats were monitored for rUO, severity of lower urinary tract signs, and medication adverse effects during hospitalization and through weekly conversations with the owner during the 1- month study period and once more at 6 months following discharge. There was no difference in the rUO rate among cats that received prazosin or placebo prior to hospital discharge (2/26 (7%) versus 1/19 (5%), P = 1.00), during the 1- month medication period (4/26 (15%) versus 3/18 (17%), P = 0.776), or at 6 months following treatment for UO (7/19 (37%) versus 4/13 (31%), P = 0.811). There was no difference in the severity of lower urinary tract signs reported by the owners at the 1-, 2-, 3-, or 4-week follow-up periods among the cats in either group (P = 0.62, 0.68, 0.33, 1.00, respectively). Reported adverse effects from prazosin administration included lethargy, ptyalism, diarrhea, anorexia, and malodorous stool. Conclusions Although our study results failed to find a difference in the incidence of rUO and severity of lower urinary tract signs among cats receiving prazosin and those receiving placebo, these study results should be interpreted cautiously as our study was underpowered to identify such differences. Larger placebo-controlled, prospective studies are needed to determine the clinical utility of prazosin in prevention of rUO.