Showing papers in "Journal of Veterinary Emergency and Critical Care in 2009"

The cell-based model of coagulation.

Abstract: Objective – To review the current model describing coagulation processes, including the critical contributions of cells. Data Sources – Original research articles, scientific reviews, and textbooks. Data Synthesis – Normal hemostasis is vital for prevention of blood loss, but controls are necessary to limit coagulation to the site of injury. The previous cascade model of blood coagulation, although refined and updated over the last few decades, is flawed as a description of how hemostasis occurs in vivo. The recently proposed model incorporates the vital role of cells in coagulation processes, and corrects deficiencies of the older cascade models. Conclusions – The cell-based model of coagulation provides a description of coagulation that more likely reflects hemostatic processes as they occur in vivo.

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

Abstract: 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 Language: en

Use of C-reactive protein to predict outcome in dogs with systemic inflammatory response syndrome or sepsis.

Abstract: Background – There is a high mortality rate in patients with systemic inflammatory response syndrome (SIRS) or sepsis. Therefore, an early diagnosis and prognostic assessment is important for optimal therapeutic intervention. The objective of the study was to evaluate if baseline values and changes in serum C-reactive protein (CRP) might predict survival in dogs with SIRS and sepsis. Design – Prospective study; July 2004 to July 2005. Setting – Small Animal Clinic, Berlin, Clinic of Small Animal Medicine, Munich. Animals – Sixty-one dogs. Measurements and Main Results – For the CRP analysis blood was drawn on day 0, 1, and 2; CRP was measured using a commercial ELISA test kit. Thirteen dogs suffered from nonseptic SIRS and 48 dogs from sepsis. The 14-day survival rate was 61% (69% nonseptic SIRS, 58% sepsis). Serum CRP was higher in sick dogs compared with controls (P<0.001). Over the 3-day period surviving dogs (n=31) displayed a significantly greater decrease in CRP than nonsurvivors (n=10) (P=0.001). No correlation was found between the initial CRP concentrations and the survival rate. The changes in CRP corresponded to the survival rate (P=0.01). Conclusion – There was no significant relationship between the survival rate in dogs with nonseptic SIRS or sepsis and the initial serum CRP concentrations. There was a correlation between decreasing CRP concentrations and recovery from disease. However, the changes in CRP concentrations over a 3-day period correctly predicted survival in 94% of dogs and death in 30% of the dogs (false positive rate 22%).

Use of thromboelastography in dogs with immune-mediated hemolytic anemia: 39 cases (2000–2008)

Abstract: Objective – To analyze thromboelastograms (TEGs) of naturally occurring cases of immune-mediated hemolytic anemia (IMHA) in order to identify whether a hypercoagulable state was present and whether its presence was associated with differences in survival. Design – Retrospective study spanning January 2000 to June 2008. Medical records of dogs were evaluated. Endpoints were considered death or discharge from the hospital. Setting – Academic teaching hospital. Animals – Thirty-nine dogs with a diagnosis of IMHA and at least one TEG performed during hospitalization were included. Interventions – None. Measurements and Main Results – Four values were evaluated from the TEG: the R time (R), K time (K), alpha angle (α), and maximum amplitude. From these values, a coagulation index (CI) was calculated to classify patients as normocoagulable, hypercoagulable, or hypocoagulable. Thirty-three of 39 patients were hypercoagulable based on the CI. The 6 remaining dogs were normocoagulable. The patients with a normocoagulable CI had an increased mortality rate (100%) when compared with the hypercoagulable patients using Fisher's exact test (P=0.02). Additionally, prolongation of partial thromboplastin time did not preclude hypercoagulable TEG values. Conclusions – The majority of dogs with IMHA were hypercoagulable as measured by TEG. A normal CI was associated with a worse outcome in this patient population. TEG may provide additional and complementary information to prothrombin time and partial thromboplastin time relating to coagulation status in dogs with IMHA and may help predict prognosis and potentially guide clinical decisions to utilize anticoagulant drugs.

The ubiquitous role of zinc in health and disease.

Abstract: Objective – To review zinc physiology and pathophysiology and the importance of zinc toxicity and deficiency in veterinary patients. Data Sources – A review of human and veterinary medical literature. Human Data Synthesis – There is a significant amount of original research in humans and animals on the role of zinc in multiple organ systems. There is also significant data available on human patients with zinc abnormalities. Veterinary Data Synthesis – Zinc deficiency has been studied in dogs with genetic disease and dietary deficiency leading to dermatological disease and immune deficiency. Zinc toxicity has been described after ingestion of metallic foreign bodies containing zinc. Conclusions – Historically, the role of zinc in health and disease has been studied through patients with toxicity or severe deficiency with obvious clinical signs. As the ubiquitous contribution of zinc to structure and function in biological systems was discovered, clinically significant but subtle deficiency states have been revealed. In human medicine, mild zinc deficiencies are currently thought to cause chronic metabolic derangement leading to or exacerbating immune deficiency, gastrointestinal problems, endocrine disorders, neurologic dysfunction, cancer, accelerated aging, degenerative disease, and more. Determining the causal relationships between mild zinc deficiency and concurrent disease is complicated by the lack of sensitive or specific tests for zinc deficiency. The prevalence of zinc deficiency and its contribution to disease in veterinary patients is not well known. Continued research is warranted to develop more sensitive and specific tests to assess zinc status, to determine which patients are at risk for deficiency, and to optimize supplementation in health and disease.

Evaluation of an abdominal fluid scoring system determined using abdominal focused assessment with sonography for trauma in 101 dogs with motor vehicle trauma.

Abstract: Objective – Evaluate an abdominal fluid scoring (AFS) system using an abdominal focused assessment with sonography for trauma (AFAST) protocol. Design – Prospective study. Setting – Private veterinary emergency center. Animals – One hundred and one client-owned dogs with motor vehicle trauma. Interventions – AFAST performed on admission and 4 hours post-admission. Measurements and Main Results – An AFS was assigned to each dog based on the number of AFAST fluid-positive quadrants identified using a 4-point scale: AFS 0 (negative for fluid in all quadrants) to AFS 4 (positive for fluid in all quadrants). Free abdominal fluid was identified in 27 of 101 dogs (27%). Dogs with AFS scores of 3 or 4 (14/27 [52%] AFS-positive dogs) experienced more marked decreases in packed cell volume and total plasma protein, increases in alanine aminotransferase, and needed more blood transfusions than dogs with lower AFS scores and AFS-negative dogs. Serial AFAST was performed in 71% of dogs (71/101); 17% (12/71) of these cases changed AFS score, and 75% (9/12) of the changes were higher (worsened) AFS, correlating with increasing amounts of free abdominal fluid. Ninety-eight percent of the study population was a primary presentation. Overall, median time from trauma to initial AFAST was 60 minutes, and median AFAST examination time was 3 minutes. Conclusions – Initial and serial AFAST with applied AFS allowed rapid, semiquantitative measure of free abdominal fluid in traumatized patients, was clinically associated with severity of injury, and reliably guided clinical management. Where possible, AFAST and AFS should be applied to the management of blunt trauma cases.

Thrombin physiology and pathophysiology.

Abstract: Objectives – To review the role of thrombin in physiology and clinical disease and to discuss the pharmacology of antithrombosis. Data Sources – Original research articles, scientific reviews, textbooks. Human Data Synthesis – Thrombin and thrombin receptors are involved in a variety of physiologic and pathologic processes resulting in a great deal of interest in thrombin-related pharmacologic intervention. Veterinary Data Synthesis – Although there is little clinical research data available on thrombin specifically in veterinary patients, some of the original research on protease activated receptors was performed at veterinary institutions and many of the human molecular biology studies have been done on animals including dogs. Conclusion – Thrombin plays a significant role in coagulation, anticoagulation, and fibrinolysis. Antithrombotic treatment is focused on preventing thrombosis while maintaining hemostasis. Pharmaceutical agents are selected for the specific component of the coagulation pathway associated with a specific disease process, for a proven prophylactic benefit with procedures that carry a risk of thromboembolism, for rapidity of onset and ease of reversibility, for limited monitoring requirements, and for oral formulation and bioavailablity. Recent insight into other aspects of thrombin physiology presents an opportunity for pharmacologic intervention in a variety of other processes such as inflammation and sepsis, peripheral blood cell activation and chemotaxis, vascular endothelial and smooth muscle activity, cellular development and tissue repair, mitogenesis, neoplasia, and the function of nervous tissue following injury.

Moxidectin toxicosis in a puppy successfully treated with intravenous lipids

Abstract: Objective – To describe successful treatment of canine moxidectin toxicosis with the novel therapy of IV lipid administration. Case Summary – A 16-week-old female Jack Russell Terrier was presented with acute onset of seizures followed by paralysis and coma shortly following suspected exposure to an equine formulation of moxidectin. Moxidectin toxicity was later confirmed. Initial therapy consisted of diazepam, glycopyrrolate, and IV fluids. Mechanical ventilation and supportive nursing care were provided as needed. An emulsion of 20% soybean oil in water, commonly used as the fat component of parenteral nutrition, was administered intravenously as a bolus of 2 mL/kg followed by 4 mL/kg/h for 4 hours beginning 10 hours after exposure and was administered again at a rate of 0.5 mL/kg/min for 30 minutes beginning 25.5 hours post-exposure. Mild improvement was seen after the first dose, and dramatic improvement was noted within 30 minutes of the second dose. The puppy's neurologic status returned to normal within 6 hours of the second administration, with no relapses. Unique Information Provided – IV lipid therapy is a novel treatment approach for moxidectin toxicity. Its use is supported by recent research and case studies involving IV lipid administration for bupivacaine and other fat-soluble toxins. Lipid administration appeared to reverse the signs of toxicity and may prove to be a highly effective therapy for moxidectin and other fat-soluble toxins.

Increasing patient safety in veterinary transfusion medicine: an overview of pretransfusion testing

Abstract: Objectives – To review the principles and available technology for pretransfusion testing in veterinary medicine and discuss the indications and importance of test performance before RBC transfusion. Data Sources – Current human and veterinary medical literature: original research articles and scientific reviews. Summary – Indications for RBC transfusion in veterinary medicine include severe anemia or tissue hypoxia resulting from blood loss, decreased erythrocyte production, and hemolyzing conditions such as immune-mediated anemia and neonatal isoerythrolysis. Proper blood sample collection, handling, and identification are imperative for high-quality pretransfusion testing. Point-of-care blood typing methods including both typing cards and rapid gel agglutination are readily available for some species. Following blood typing, crossmatching is performed on one or more donor units of appropriate blood type. As an alternative to technically demanding tube crossmatching methods, a point-of-care gel agglutination method has recently become available for use in dogs and cats. Crossmatching reduces the risk of hemolytic transfusion reactions but does not completely eliminate the risk of other types of transfusion reactions in veterinary patients, and for this reason, all transfusion reactions should be appropriately documented and investigated. Conclusion – The administration of blood products is a resource-intensive function of veterinary medicine and optimizing patient safety in transfusion medicine is multifaceted. Adverse reactions can be life threatening. Appropriate donor screening and collection combined with pretransfusion testing decreases the occurrence of incompatible transfusion reactions.

Thrombelastography in 26 healthy horses with and without activation by recombinant human tissue factor.

Abstract: Objectives – To develop a standardized technique for thrombelastography (TEG) analysis in healthy adult horses, with and without the ex vivo addition of tissue factor (TF) as an activator. To determine reference intervals for TEG parameters in the horse, and to determine if traditional coagulation tests correlate with TEG. Design – Prospective, observational. Setting – Veterinary teaching hospital. Animals – Twenty-six healthy adult horses. Interventions – None. Measurements and Main Results – Thrombelastography with (TF-TEG) and without (TEG) the addition of TF performed by 4 operators. Coagulation profiles (prothrombin time, activated partial thromboplastin time, platelet count, fibrinogen, antithrombin, and fibrinogen degradation products) were assessed in a subset of horses. Mean values (SD) for TEG parameters in healthy horses were: reaction time (R)=17.0 minutes (3.0 min), K time (K)=5.8 minutes (2.3 min), clotting rate (Ang)=42° (14°), maximum clot strength (maximum amplitude [MA])=60.3 mm (5.7 mm), CL30=97.0% (2.0%), LY30=0.8% (0.6%), CL60=92% (5.9%), LY60=3.2% (2.5%). Mean values (SD) for TF-TEG parameters were: R-TF=6.6 minutes (1.4 min), K-TF=3.1 minutes (1.0 min), Ang-TF=50.9° (9°), MA-TF=62.3 mm (5.1 mm), CL30-TF=97.8% (1.6%), LY30-TF=0.6% (0.5%), CL60-TF=90.8% (4.2%), and LY60-TF=3.6% (1.9%). The addition of TF decreased R and K and increased Ang. TF-TEG had a narrower SD for R, K, Ang, CL60 and LY60 compared with TEG. Interoperator differences were reduced by the addition of TF. Regression analysis indicated a positive relationship between MA and fibrinogen concentrations (P=0.02) and R-TF time and prothrombin time (P=0.03). Conclusion – TF-TEG using the described protocol may minimize variability in data obtained across institutions or users. However, due to the variability associated with different operators, it is recommended that each laboratory set up individual reference intervals with the personnel who will perform the assay, and that the assay protocols and data obtained are compared on a regular basis.

Elevation of alanine transaminase and gallbladder wall abnormalities as biomarkers of anaphylaxis in canine hypersensitivity patients.

Abstract: Objective – The purpose of the study was to evaluate alanine transaminase (ALT) and gallbladder wall abnormalities as possible biomarkers for anaphylaxis in dogs presented for acute hypersensitivity reactions. Design – Pilot study. Setting – A private practice, small animal, 24-hour emergency and specialty hospital. Animals – Ninety-six dogs presenting 101 times on an emergency basis for hypersensitivity reactions from March 2007 through March 2009. Interventions – Veterinarians acquired a history, physical exam, serum chemistry panel, blood pressure, and ultrasound image of the gallbladder. Measurements and Main Results – Dogs were then divided into 2 groups: dogs fulfilling the definition for anaphylaxis (moderate and severe systemic hypersensitivity) and dogs that did not fulfill the definition and were classified as allergic reactions (local hypersensitivity and mild systemic hypersensitivity). Elevated ALT was significantly associated with anaphylaxis (P<0.001). Increased gallbladder wall thickness and a striated wall pattern were significantly associated with anaphylaxis (P<0.001) and these changes were readily apparent to first-responder veterinarians. Decreased body temperature (P<0.001) and hypothermia (P=0.006) were significantly associated with anaphylaxis. There was no significant difference between groups regarding age, heart rate, or presence of respiratory signs. Lower blood pressure was significantly associated with anaphylaxis (P<0.001) but hypotension was not significantly different (P=0.09) between groups. Cutaneous signs were significantly associated with the allergic reactions group (P<0.001) and, when seen with anaphylaxis, were subtle. Conclusions – This study showed an elevated ALT and an abnormal gallbladder wall to be biomarkers significantly associated with anaphylaxis in dogs with acute hypersensitivity reactions.

Clinical and biochemical abnormalities in endurance horses eliminated from competition for medical complications and requiring emergency medical treatment: 30 cases (2005-2006).

Abstract: Objective – To describe the clinical and clinicopathologic abnormalities in endurance horses eliminated from competition and requiring emergency medical treatment. Design – Retrospective study over a 2-year period (2005–2006). Ten horses that successfully completed the ride in 2006 were included for comparison. Setting – Temporary equine emergency field hospital. Animals – All horses (n=30) that were removed from endurance competition and treated for a metabolic abnormality were studied. Interventions – Horses were treated with IV fluids and analgesics. Monitoring included lab work (PCV, total protein, and electrolytes) and serial physical examinations. Statistical analysis included descriptive statistics and parametric and nonparametric comparisons (ANOVA, Friedman's test, and Kruskal-Wallis) where appropriate. Measurements and Main Results – The clinical diagnoses identified included colic, esophageal obstruction, poor cardiovascular recovery, myopathy, and synchronous diaphragmatic flutter. As a group, these sick horses had lower plasma chloride and potassium and higher total plasma protein concentrations as compared with 10 healthy horses that successfully completed the ride (P<0.05, <0.01, and <0.05 for chloride, potassium, and total protein, respectively). Horses with colic had a lower PCV as compared with horses with poor recovery and those with synchronous diaphragmatic flutter (P<0.05). All horses, including colics, were treated medically and discharged to owners. Conclusions – Based on the results of this study, the prognosis for horses requiring emergency veterinary treatment after being removed from endurance competition (for metabolic reasons) appears to be good if horses are withdrawn from competition under the same criteria outlined in this study. Biochemical abnormalities tend to be mild and do not necessarily aid in delineating sick horses from successfully completing horses. None of the horses with gastrointestinal disease required abdominal surgery.

The effect of Hetastarch (670/0.75) in vivo on platelet closure time in the dog

Abstract: Objective To evaluate the effect of 6% hydroxyethyl starch (HES) solution in vivo, with an average molecular weight of 670 kDa and degree of substitution of 0.75, on canine platelet function. Design Prospective, controlled- experimental study. Setting University of California, Davis, Veterinary Medical Teaching Hospital. Animals Seven healthy employee-owned dogs. Interventions Seven dogs were included in the treatment group. Four of these dogs also served as the control group. Platelet closure time (CT) was measured using a platelet function analyzer and collagen/ADP cartridges. Dogs were given 20 mL/kg of either sodium chloride 0.9% (control group, n=4) or HES (treatment group, n=7) IV over 1 hour. CT was measured before the infusion, and at 1, 3, 5, and 24 hours after the start of the infusion. Measurements and Main Results There was a significant change over time from 0 to 24 hours (P<0.001), a significant difference between groups across time (P<0.001), and a significant group-by-time interaction (P=0.007). At 3 hours, mean CT for the treatment group was 122.3±18.1 seconds, which was significantly different (P<0.001) from the control group (71.0±3.5 s). At 5 hours, mean CT for the treatment group was 142.7±33.9 seconds, which was significantly different (P=0.001) from the control group (75.0±8.6 s). Mean CT at 24 hours was within the reference interval for both the control and treatment group (66.0±2.9 and 81.8±11.9 s, respectively); however, CT in 3 individual dogs in the treatment group at this time point remained prolonged. Conclusions A clinically relevant dose of HES 670/0.75 prolongs CT in dogs for up to 24 hours. This may be due to platelet dysfunction in addition to the effects of hemodilution, and therefore, may increase the risk of bleeding.

Coagulopathy of the critically ill equine patient.

Abstract: Objective – To review the hemostasis literature relevant to development of coagulopathy in the critically ill equine patient. Data Source – Original scientific and review articles. Human Data Synthesis – Inflammation plays a critical role in the activation and amplification of clot formation, as well as the impairment of physiologic anticoagulant mechanisms, and fibrinolysis. Earlier identification of coagulopathy in patients at risk and restoration of physiologic hemostasis may result in better outcome. Development of scoring systems based on information other than coagulation markers alone may better identify patients with subclinical coagulopathy. Veterinary Data Synthesis – Critically ill equine patients commonly at risk for coagulopathy include those with severe gastrointestinal disease, septic foals, and adults subjected to severe systemic inflammatory response syndrome. Publications provide information regarding coagulation markers helpful for identification of hemostatic dysfunction in specific patient populations, as well as information regarding the influence of coagulopathy on outcome. Data regarding clinically relevant information on therapeutic intervention are lacking. Conclusions – The relationship between inflammation and endotoxemia and development of coagulopathy is better understood in both human patients and the critically ill equine patient. Prospective clinical trials evaluating clinically relevant and financially feasible approaches to treatment are still needed.

Evaluation of low-molecular-weight heparin for the prevention of equine laminitis after colic surgery.

Abstract: Objectives – The aim of this study is to describe the prevalence of postoperative laminitis in colic cases and to determine if low-molecular-weight heparin (LMWH) is effective in preventing this complication. Design – Retrospective clinical study. Animals – Client-owned horses. Interventions – SC administration of enoxaparin during the postoperative period. Measurements and Main Results – Medical records of 360 horses undergoing surgery for colic and surviving at least 3 days were evaluated. Fifty-six horses admitted before 1995 did not receive LMWH (control group) and 304 admitted after 1995 received LMWH as a prophylaxis for laminitis (treatment group). Three grades of severity were defined for laminitis. Prevalence and severity of laminitis were compared between the 2 groups. Several parameters recorded on admission (sex, age, breed, site and nature of the disease, heart rate, PCV, gravity score, and shock score) and the administration of LMWH were tested as risk factors in the development of laminitis in a logistic regression procedure. Prevalence and grade of laminitis were significantly lower in the treatment group. Only the absence of LMWH was recognized as a significant risk factor in the logistic regression model. Conclusions – The administration of LMWH appears to be effective in the prophylaxis of laminitis following colic surgery and may be useful in the postoperative management of these horses.

Use of human immunoglobulin in addition to glucocorticoids for the initial treatment of dogs with immune-mediated hemolytic anemia.

Abstract: Objective –To determine the utility of human intravenous immunoglobulin (hIVIG) for the initial treatment of canine immune-mediated hemolytic anemia (IMHA). Design –Blinded, randomized, clinical trial. Setting –Veterinary teaching hospital. Animals –Twenty-eight, client-owned dogs with primary IMHA. Interventions –At enrollment, after diagnosis of IMHA, dogs were randomly assigned to receive either hIVIG or placebo, in a blinded fashion. For the next 14 days, all dogs received glucocorticoids as the sole immunosuppressant agent. All dogs received low-molecular-weight heparin as an anticoagulant. D-dimer concentrations were evaluated at the beginning and end of the study protocol to monitor for thromboembolic complications. Measurements and Main Results –Twenty-five of 28 dogs (89%) were discharged from the hospital. Thirteen of those received hIVIG and 12 received placebo. Twenty-four dogs (86%) were alive 14 days after enrollment, and of these 13 received hIVIG and 11 received placebo. D-dimer concentrations were elevated in 86% of all dogs at the time of diagnosis. Conclusions –For initial treatment of dogs with IMHA, the addition of hIVIG to corticosteroid treatment did not improve initial response, nor did it shorten hospitalization.

Antimicrobial therapy and aerobic bacteriologic culture patterns in canine intensive care unit patients: 74 dogs (January-June 2006).

Abstract: Objective – Describe antimicrobial therapy and aerobic bacteriologic culture patterns in canine intensive care unit (ICU) patients in a university hospital. Design – Retrospective descriptive. Setting – A tertiary university referral hospital. Animals – Seventy-four canine ICU patients. Interventions – From January to June 2006 patient antimicrobial use, minimum inhibitory concentration (MIC) results, and clinical data were recorded. Appropriate antimicrobial use was analyzed relative to the time of culture submission and MIC results. Measurements and Main Results – Mean±SD age was 7.2±4.2 years. Median (range) length of ICU and hospital stays were 3 days (1–25 d) and 4 days (1–27 d), respectively. A total of 106 cultures were submitted; 47 of 106 (44%) cultures were positive for 70 isolates, including Escherichia coli (16/70 [23%]), Staphylococcus intermedius (7/70 [10%]), and Acinetobacter baumannii (5/70 [7%]). A multidrug resistant pattern occurred in 19 of 70 (27%) isolates, and was significantly more likely after 48 hours of hospitalization (P<0.001). Antimicrobials were administered before culture submission in 42 of 74 dogs (57%) and included enrofloxacin (23/42 [55%]), ampicillin (20/42 [48%]), and amoxicillin/clavulanic acid (8/42 [19%]). Antimicrobial choices were appropriate 19% of the time. While pending culture results, antimicrobials were administered to 67 of 72 (94%) dogs remaining alive, and were appropriate 75% of the time. The most common antimicrobials administered while awaiting culture results were ampicillin (52/67 [78%]), enrofloxacin (49/67 [73%]), and amikacin (9/67 [13%]). Post-MIC antimicrobials were appropriate 89% of the time. Of 45 dogs remaining alive, 17 (37%) continued to receive antimicrobials despite negative cultures. Conclusions – Antimicrobial use was extensive in this patient population, but when available, MIC results were used to guide antimicrobial therapy. Many patients with negative cultures continued to receive antimicrobial therapy. Multidrug resistant bacteria were more likely in cultures taken after 48 hours of hospitalization.

Canine platelet transfusions

Abstract: Objective – To review potential platelet storage options, guidelines for administration of platelets, and adverse events associated with platelet transfusions. Data Sources – Data sources included original research publications and scientific reviews. Human Data Synthesis – Transfusion of platelet concentrates (PCs) plays a key role in the management of patients with severe thrombocytopenia. Currently PCs are stored at 22°C under continuous gentle agitation for up to 5 days. Chilling of platelets is associated with rapid clearance of transfused platelets, and galactosylation of platelets has proven unsuccessful in prolonging platelet survival. Although approved by the American Association of Blood Banks, cryopreservation of human platelets in 6% DMSO largely remains a research technique. Pre-storage leukoreduction of PCs has reduced but not eliminated acute inflammatory transfusion reactions, with platelet inflammatory mediators contributing to such reactions. Veterinary Data Synthesis – Canine plateletpheresis allows collection of a concentrate with a high platelet yield, typically 3–4.5 × 1011 versus <1 × 1011 for whole blood-derived platelets, improving the ability to provide sufficient platelets to meet the recipient's transfusion needs. Cryopreservation of canine platelets in 6% DMSO offers immediate availability of platelets, with an acceptable posttransfusion in vivo platelet recovery and half-life of 50% and 2 days, respectively. While data on administration of rehydrated lyophilized platelets in bleeding animal models are encouraging, due to a short lifespan (min) posttransfusion, their use will be limited to control of active bleeding, without a sustained increase in platelet count. Conclusions – Fresh PC remains the product of choice for control of bleeding due to severe thrombocytopenia or thrombopathia. While cryopreservation and lyophilization of canine platelets offer the benefits of immediate availability and long-term storage, the compromise is decreased in vivo recovery and survival of platelets and some degree of impaired function, though such products could still be life saving.

Severe seizures associated with traumatic brain injury managed by controlled hypothermia, pharmacologic coma, and mechanical ventilation in a dog.

Abstract: Objective – To describe the management and outcome of a dog presenting with intractable seizures associated with traumatic brain injury Case Summary – A spayed female Wheaten Terrier was presented to an emergency clinic with neurologic deficits (modified Glasgow coma scale of 10) shortly after a road traffic accident Seizures were uncontrolled despite aggressive pharmacologic intervention Controlled hypothermia to achieve a rectal temperature of 33–35°C (914–95°F) was initiated as a protective measure to reduce intracranial pressure and cerebral metabolic rate, and to assist with seizure control Intubation and mechanical ventilation were required to protect the airway and manage hypercapnia associated with hypoventilation The patient went on to make a full recovery, although behavioral changes were noted by the owners for an 8-week period following injury New or Unique Information Provided – To the author's knowledge, this is the first instance of therapeutic hypothermia reported in the veterinary literature A short review of this treatment modality is provided

Critical illness-related corticosteroid insufficiency in a dog with septic shock.

Abstract: Objective – To describe a case of hydrocortisone-responsive hypotension and critical illness-related corticosteroid insufficiency (CIRCI) in a dog with septic shock. Case Summary – A dog with aspiration pneumonia developed septic shock with pressor-refractory hypotension. A standard ACTH stimulation test was performed that showed a blunted cortisol response consistent with CIRCI. Reversal of shock was achieved within 2 hours of hydrocortisone administration, and complete weaning from pressors was accomplished over the subsequent 8 hours. The patient recovered and was discharged from the hospital. An ACTH stimulation test performed 1 month after hospital discharge showed normal adrenal responsiveness consistent with resolution of CIRCI. New or Unique Information Provided – This case is the first published report of hydrocortisone-responsive hypotension and transient CIRCI associated with naturally occurring septic shock in a dog.

Evaluation of fresh frozen plasma administration in dogs with pancreatitis: 77 cases (1995-2005)

Abstract: Objective – Compare outcome of dogs that did and did not receive fresh frozen plasma (FFP) for treatment of pancreatitis. Design – Retrospective case series between 1995 and 2005. Setting – University referral hospital. Animals – Seventy-four dogs were enrolled with a total of 77 cases as 2 dogs had repeat episodes of pancreatitis. Diagnosis of pancreatitis was based on clinical signs, physical examination, and abdominal ultrasonographic examination. Interventions – The medical database was searched for dogs with a diagnosis of pancreatitis. Information collected included signalment, vital signs, CBC, use of FFP, length of stay, use of antimicrobials and supplemental nutrition, surgical intervention, preexisting illness, evidence of a coagulopathy and outcome. Outcome was compared between those patients that did and did not receive FFP. Measurements and Main Results – Fifty-nine dogs survived to discharge. Two dogs with repeat pancreatitis survived to discharge after each episode. Thirteen dogs died and 2 were euthanized. FFP was administered to 20 dogs. Two dogs that were hospitalized for repeat pancreatitis did not receive FFP. Seven of 20 (35%) cases that received plasma died or were euthanized compared with 6 of 57 (12%) cases that did not receive plasma. Plasma administration was significantly related to outcome (P<0.001). Severity of illness scores were difficult to assign, however, dogs meeting criteria for systemic inflammatory response syndrome were not more likely to receive FFP. Other therapies included supplemental nutrition, antimicrobials, and surgical intervention, which did not affect outcome. Conclusions – Mortality rate for those dogs receiving plasma was higher than those that did not. Severity of illness scores were difficult to assign; however, preexisting illness, evidence of systemic inflammatory response syndrome, and presence of a coagulopathy were not significantly different between the groups that did and did not receive FFP. No benefit for administration of FFP was noted. Additional investigation should be performed to confirm this result.

Comparison of viscoelastic coagulation analysis and standard coagulation profiles in critically ill neonatal foals to outcome

Abstract: Objective – To determine if changes in viscoelastic variables are associated with abnormalities observed in the standard coagulation profile and patient outcome in foals with suspected septicemia. Design – Prospective clinical trial during 2003 and 2004 foal season. Setting – Neonatal intensive care unit at a veterinary teaching hospital. Animals – Thirty critically ill foals o72-hour-old admitted sequentially meeting criteria for systemic inflammatory response associated with infection. Interventions – Hemostatic evaluation, using standard coagulation testing and viscoelastic analysis, was performed at admission, 24 hours following admission, and 48 hours following admission in critically ill foals. Standard coagulation tests included platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen, fibrin(ogen) degradation products, and antithrombin. Data collected from viscoelastic analysis included time to initial clot formation (ACT), clot rate, and platelet function. Signalment, blood culture results, clinicopathologic data, and outcome were collected from medical records. Equality of populations test was used to determine associations between coagulation tests and blood culture status/outcome, as well as between viscoelastic parameters and coagulopathy, blood culture status, and outcome. Logistic regression was used to quantify associations. A significance level of Po0.05 was used. Measurements and Main Results – Foals with decreasing clot rate (CR) over the sample period were more likely to be euthanized or die (P 50.02). Foals with prolonged ACT (P 50.03), and decreased CR at admission (P 50.047), were more commonly coagulopathic. Identification of coagulopathy on admission (P 50.02), or persistence of hemostatic dysfunction 48 hours later (P 50.04), was associated with death. Conclusions – Viscoelastic coagulation evaluation could be used in a neonatal intensive care unit setting to further characterize coagulopathy, and identify foals at higher risk for poor outcome.

The role of tissue factor and tissue factor pathway inhibitor in health and disease states

Abstract: Objective – To review the veterinary and human literature on the role of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in health and disease states. Data Sources – Original research articles and scientific reviews from both human and veterinary literature were searched for relevance to TF and TFPI. Human Data Synthesis – Interest in both TF and TFPI has grown widely over the last several years. The impact TF plays in coagulation, inflammation, angiogenesis, tumor metastasis, and cellular signaling has become apparent. Treatment with TFPI for severe sepsis has been examined and is still currently under investigation. Inhibition of the TF pathway is being studied as an aid in the treatment of neoplasia. The important physiologic and pathophysiologic role these molecules play has only begun to be understood. Veterinary Data Synthesis – There is a paucity of publications that discuss the importance of TF and TFPI in veterinary medicine. An enhanced understanding of the TF pathway in human medicine, in experimental animal models treating sepsis with TFPI, and in animal models demonstrating the proangiogenic properties of TF provides relevance to veterinary medicine. Conclusion – It is apparent that TF and TFPI are important in health and disease. An enhanced understanding of the physiologic and pathophysiologic roles of these factors provides better insight into coagulation, inflammation, angiogenesis, disseminated intravascular coagulation, and tumor metastasis. This greater understanding may provide for the development of therapeutics for sepsis, disseminated intravascular coagulation, and neoplasia.

Histamine: metabolism, physiology, and pathophysiology with applications in veterinary medicine

Abstract: Objective – To review the human and veterinary literature on histamine physiology and pathophysiology and potential applications for clinical use in veterinary critical care. Data Sources – Human and veterinary clinical studies, reviews, texts, and recent research in histamine receptor and antagonist therapy. Human Data Synthesis – Recent progress in molecular biology has led to a more complete understanding of the enzymes involved in histamine metabolism and histamine receptor physiology. The past decade of research has confirmed the role of histamine in the classical functions (contraction of smooth muscle, increase in vascular permeability, and stimulation of gastric acid secretion) and has also elucidated newer ones that are now under investigation. Data on the roles of histamine in angiogenesis, circadian rhythm, bone marrow regeneration, bacterial eradication, and cancer are emerging in the literature. Newer histamine antagonists are currently in drug trials and are expected to advance the clinical field in treatment of allergic, gastrointestinal, and cognitive disorders. Veterinary Data Synthesis – Veterinary histamine research is directed at identifying the effects of certain pharmacological agents on blood histamine concentrations and establishing the relevance in clinical disease states. Research demonstrates important species differences in regards to histamine receptor physiology and tissue response. Studies in the area of trauma, sepsis, anaphylaxis, allergy, and gastrointestinal disorders have direct applications to clinical veterinary medicine. Conclusions – Histamine plays a key role in the morbidity and mortality associated with allergy, asthma, gastric ulcers, anaphylaxis, sepsis, hemorrhagic shock, anesthesia, surgery, cardiovascular disease, cancer, CNS disorders, and immune-mediated disease. Histamine antagonism has been in common use to block its adverse effects. With recent advances in the understanding of histamine receptor physiology, pharmaceutical agents targeting these receptors have increased the therapeutic options.

Use of mycophenolate mofetil as a rescue agent in the treatment of severe generalized myasthenia gravis in three dogs

Abstract: Objective – To describe the use of IV and oral mycophenolate mofetil (MMF) as adjunctive therapy in 3 dogs with severe generalized myasthenia gravis. Case Series Summary – Three dogs suffering from severe generalized myasthenia gravis as confirmed by acetylcholine antibody titers were treated with MMF as part of their treatment regimens. All 3 dogs had radiographic evidence of megaesophagus and suffered from severe regurgitation. Each dog was initially treated with pyridostigmine and supportive agents. When clinical remission was not achieved, IV MMF was administered to all dogs. Signs of clinical remission were apparent within 48 hours and all dogs were later maintained on oral MMF following resolution of regurgitation. New or Unique Information Provided – This is the first report of the use of IV MMF as adjunctive treatment in dogs with severe generalized myasthenia gravis. Outcome was favorable in all 3 dogs and no adverse effects were noted from the MMF.

Diaphragmatic hernia in horses: 44 cases (1986–2006)

Abstract: Objectives – To present a case series of horses diagnosed with diaphragmatic hernia, and to determine the significance of (1) historical information, examination findings, and laboratory data; and (2) exploratory laparotomy or necropsy findings on short- and long-term outcome. Setting – University Referral Hospital. Design – Retrospective study. Animals – Forty-four horses/foals admitted between 1986 and 2006 with a diagnosis of diaphragmatic hernia made either at exploratory laparotomy or necropsy. Interventions – None. Measurements and Main Results – Information from the medical records included history, clinical examination findings at presentation, and findings of exploratory laparotomy or necropsy. Logistic regression or the Fisher exact test was used to determine factors associated with survival. Outcome was defined as survival to discharge (short-term survival), and long-term survival was defined as horses alive at least 1-year post surgery. Of the 44 horses, 18 died or were euthanized before surgery. Twenty-six were taken to surgery, 17 were euthanized. Nine horses recovered from anesthesia, 7 of which survived to hospital discharge. Of these, 5 were alive at long-term follow-up. Survival was significantly associated with the age of the horse (≤2 y old) at presentation, presence of normal peritoneal fluid at presentation, amount of compromised viscera at surgery (<50% small intestine), and the size (<10 cm) and location (ventral) of the diaphragmatic tear. Conclusion – This study confirms that size and location of the lesion do play a significant role in prognosis. And, although the prognosis for horses with diaphragmatic hernia is poor, if horses have operable lesions there is a fair prognosis for long-term survival.

Coagulation effects of low molecular weight heparin compared with heparin in dogs considered to be at risk for clinically significant venous thrombosis.

Abstract: Objective – Compare the effects of 3 anticoagulation protocols on anti-factor Xa activity (AXa). Design – Prospective, randomized, double-blind study. Setting – University veterinary teaching hospital. Animals – Eighteen dogs considered to be at risk for venous thrombosis. Interventions – Each dog was randomly assigned to 1 of the following 3 groups (n=6/group) and was treated for 24 hours: low-dose heparin (LDH), high-dose heparin (HDH), and dalteparin (DP). Dogs in the LDH group received a constant rate infusion (CRI) of unfractionated heparin (UFH) at 300 U/kg/d, the HDH group received a bolus of 100 U/kg of UFH IV, then a CRI of 900 U/kg/day, and the DP group received 100 U/kg DP SC at 0, 12, and 24 hours. Measurements and Main Results – A total of 54 samples for activated partial thromboplastin time (aPTT) and AXa assays were collected at 0, 4, and 28 hours. Six samples had an AXa >0.1 U/mL, 5 of those were from the HDH group at hour 4. Two samples from the HDH group at hour 4 had a prolonged aPTT (93 and 200 seconds) and the highest AXa (0.6 and 1.0 U/mL, respectively). Four additional dogs in the HDH group did not complete the study due to hemorrhage; none of the dogs completing the study showed signs of hemorrhage. Conclusions: Neither DP nor LDH increased AXa to values considered therapeutic in humans (0.5–1 and 0.35–0.75 U/mL, respectively), and both protocols appear to be inadequate to increase AXa in dogs with clinical illness. HDH increased AXa to this range in 2 of 6 dogs, but had unpredictable effects on aPTT and resulted in hemorrhage in some dogs.

Nasogastric tube feeding in cats with suspected acute pancreatitis: 55 cases (2001-2006).

Abstract: Objective – To evaluate the complications and outcome associated with different nasogastric tube (NGT) feeding techniques in cats with suspected acute pancreatitis. Design – Descriptive retrospective case series Setting – Small animal emergency and referral hospital Animals – The patient database (2001-2006) was searched for cats with suspected acute pancreatitis that received NGT liquid enteral feeding within 72 hours of admission and ≥12 hours during hospitalization. Measurements and Main Results – Signalment, history, clinical signs, laboratory data and abdominal ultrasonographic examinations were used for suspected diagnosis. Cats were grouped based upon whether they received bolus feeding or continuous rate infusion (CRI) of a liquid diet via the NGT, and whether or not administration of an intravenous amino acid and carbohydrate solution occurred prior to NGT feeding (AAS and non-AAS group, respectively). Fifty-five cats were included. For all cats, NGT feeding was initiated at a mean of 33.5 ± 15.0 hours and the target caloric intake (1.2 X {(30 X BW [kg]) +70}) was reached at 58.0 ± 28.4 hours from presentation. There was a significantly longer time from admission to the initiation of NGT feeding in the 34/55 cats in the AAS group vs. the 21/55 cats in the non-AAS group (P = 0.009). The 8 bolus-fed cats took longer to reach target caloric intake vs. the 47 CRI-fed cats (P = 0.002). Complications associated with NGT feeding for all cats included: mechanical problems (13%), diarrhea (25%), vomiting following NGT placement (20%) and vomiting following NGT feeding (13%). Mean time to discharge for all cats occurred after 78.6 ± 29.5 hours with an overall weight gain of 0.08 ± 0.52 kg. Fifty cats survived 28 days post-discharge. Conclusions – NGT feeding in this group of cats with suspected acute pancreatitis was well tolerated, and associated with a low incidence of diarrhea, vomiting, and mechanical complications.

Effect of antivenin dose on outcome from crotalid envenomation: 218 dogs (1988-2006).

Abstract: Objective – To determine whether the dose of antivenin administered is associated with a difference in survival of crotalid-envenomated dogs. A secondary objective was to determine whether other covariables affect survival. Design – Retrospective study (1988–2006). Setting – Private referral center and university small animal teaching hospital. Animals – Two hundred and eighteen dogs with evidence of crotalid envenomation and treatment with equine-derived antivenin. Interventions – Administration of antivenin. Measurements and Main Results – Patient signalment, physical and clinicopathologic data at time of presentation, treatments, complications of antivenin therapy, length and cost of hospitalization, and outcome were recorded. Confidence intervals were determined for the difference in median number of vials administered and for median dosage for patients that lived versus died. Penalized logistic regression was performed to evaluate the effect of other covariables on survival. The median age of affected dogs was 3 years (range 6 w–12 y) with a median weight of 25.7 kg (range 1.95–86.4 kg). The median number of antivenin vials administered was 1.0 (range 1.0–10.0). Acute and chronic reactions were reported in 7% (16/218) and 0.9% (2/218) of dogs, respectively. Nine of 218 dogs (4.1%) died. The median number of vials administered to the nonsurvivors and survivors were 2.0 (range 1–5 vials) and 1.0 (range 1–10 vials), respectively. The median number of vials received was significantly different in dogs that died versus those that lived (P<0.05). Increased heart rate (P=0.02) and petechiation (P=0.04) were associated with decreased likelihood of survival, while diphenhydramine (P=0.02) and fluoroquinolone (P=0.046) administration was associated with increased likelihood of survival. The median duration of hospitalization was 1.0 day (range 2 h–22 d). The median cost of hospitalization was US$1592.00 (range US$267.20–US$6738.00). Conclusion – The administration of more vials of antivenin is potentially associated with negative outcome; however, a causal relationship has not been established. Controlled, prospective studies are needed to optimize antivenin administration.

Use of therapeutic plasmapheresis in a case of canine immune-mediated hemolytic anemia.

Abstract: Objective – To investigate the clinical application and potential utility of plasmapheresis in canine immune-mediated hemolytic anemia. Case Summary – A 7-year-old spayed female Maltese diagnosed with immune-mediated hemolytic anemia was initially treated with prednisone, cyclosporine, and received multiple transfusions of packed RBC. Because of the progression of clinical signs despite traditional medical therapy, plasmapheresis was initiated. Plasma immunoglobulin G and immunoglobulin M levels were measured before, during, and after treatment to help determine if there had been a significant decrease in immunoglobulin levels with plasmapheresis. Plasmapheresis was successfully performed over a 2.5-hour period in this dog with minimal complications. Hypocalcemia was identified as a known complication of circuit anticoagulation, and was corrected through calcium supplementation. Post-plasmapheresis there was a decrease in immunoglobulin G and immunoglobulin M levels, and the patient showed clinical improvement. Following discharge the dog had no known complications of therapy, and had complete resolution of the anemia. New or Unique Information Provided – Plasmapheresis was performed successfully with minimal complications. Because transfusion requirements appeared to be reduced, and the procedure was well tolerated, there may be a place for this modality in severe cases to act as a bridge until medical therapy takes full effect. Because of the cost of performing this therapy, and the potential requirement for multiple treatments, it should be reserved for selected patients.