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Objective: To compare in vivo central venous hemoglobin saturation measurement (ScvO2) using a fiber optic catheter with saturation calculated from blood gas analysis in critically ill dogs. Design: Prospective observational study. Setting: University veterinary teaching hospital intensive care unit. Animals: A convenience sample of 20 dogs with severe illness. Interventions: Dogs were instrumented with either a central venous catheter with an integrated fiber optic cable or a conventional catheter with a fiber optic probe inserted through its distal port. Baseline saturation was measured with the fiber optic system (FSO2), then monitored continuously. Central venous blood was collected for analysis and FSO2 was recorded by the principal investigator (PI) or nursing staff participating in data collection (staff) at baseline and at 1, 2, 3, and 6 hours. Hemoglobin oxygen saturation (SO2) values calculated using human Bohr coefficients were taken directly from the analyzer (GPSO2), and were also calculated using temperature‐correction and canine Bohr coefficients (RSO2). Measurements and Main Results: Ninety‐seven paired measurements from 20 dogs were analyzed. FSO2 obtained by the PI (n = 41) had better agreement with both GPSO2 (concordance correlation coefficient ρc = 0.926 vs 0.5562) and RSO2 (ρc = 0.75 for PI vs 0.54) than did staff (n = 56). RSO2 values were always smaller than GPSO2. FSO2 ‐ GPSO2 differences were smaller when measurements were collected by the PI versus Staff (mean difference 0.21 vs −6.6, respectively, P < 0.02). Thirty‐six of 41 FSO2 values obtained by PI were within 5% of GPSO2. Conclusions: Concordance between FSO2 and either calculation method was low, but was better when performed by PI. The larger difference between methods when using RSO2 suggests a positive bias by FSO2. Difficulty obtaining stable measurements may have contributed to the poor concordance between methods within Staff. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To review clinically relevant features of systemic oxygen delivery and consumption and the technique and use of venous oxygenation monitoring in human and veterinary medicine. Data sources: Veterinary and human peer‐reviewed medical literature including scientific reviews, clinical and laboratory research articles, and authors’ clinical research experience. Summary: Measurement of venous hemoglobin oxygen saturation (venous oxygenation) provides insight into the balance between oxygen supply and tissue demand. In people, measurement of venous oxygen saturation can reveal decompensation that is missed by physical examination and other routinely monitored parameters. Therefore, measurement of mixed or central venous oxygenation measurement may help guide therapy and predict outcome of critically ill patients. In dogs, low central venous oxygen saturation has been associated with impaired cardiopulmonary function and poor outcome in several small studies of experimental shock or severe clinical illness, suggesting that monitoring this variable may assist the treatment of severe illness in this species as well. Conclusion: Venous oxygenation reflects systemic oxygenation status and can be used to guide treatment and estimate prognosis in critically ill patients. Measurement of venous oxygenation in veterinary patients is feasible and is a potentially valuable tool in the management of patients with severe disease. This review is intended to increase the understanding and awareness of the potential role of venous oxygen measurement in veterinary patients. [ABSTRACT FROM AUTHOR]

Objective To summarize current understanding of the mechanisms responsible for changes occurring during red blood cell (RBC) storage, collectively known as the storage lesion, and to review the biological and clinical consequences of increasing storage time of RBCs. Data Sources Human and veterinary clinical studies, experimental animal model studies, and reviews of the RBC storage lesion with no date restrictions. Human Data Synthesis Experimental studies have characterized the evolution of human RBC and supernatant changes that occur during storage and form the basis for concern about the potential for harm from long-term storage of RBCs. Although 4 randomized controlled trials of varying sizes failed to find an association between RBC storage time and negative clinical outcomes, a recent meta-analysis and numerous observational clinical studies have demonstrated that transfusion of old versus fresh stored RBCs is associated with an increased risk of morbidity and mortality, particularly among trauma victims and cardiac surgery patients. Potential clinical consequences of RBC transfusion following development of the storage lesion include risk of organ dysfunction, organ failure, infections, and death. Veterinary Data Synthesis Experimental animal models have contributed to the evidence supporting adverse consequences of the RBC storage lesion. Studies on relevant RBC storage issues such as the effect of different preservative solutions and leukoreduction have been completed. Transfusion with RBCs stored for 42 days increases mortality in dogs with experimental sepsis. Conclusion Storage of RBCs induces progressive biochemical, biomechanical, and immunologic changes that affect red cell viability, deformability, oxygen carrying capacity, microcirculatory flow, and recipient response. Most reports in the human and veterinary literature support the concept that there are deleterious effects of the RBC storage lesion, but additional studies with improved experimental design are needed to identify compelling reasons to modify current blood banking and transfusion practices. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective– To characterize the signalment, clinical findings, and prognosis of dogs with supraventricular tachycardia (SVT). Design– Retrospective study. Setting– North Carolina State University Veterinary Teaching Hospital. Animals, Intervention, and Measurements– Case selection included all patients at the veterinary teaching hospital with SVT during years 1990–2007. Medical records from dogs with at least 1 recorded episode of SVT were extracted. The signalment, history, electrocardiographic, radiographic, and echocardiographic findings, therapy, and response to therapy were reviewed and summarized. Follow-up was conducted to determine the date and cause of death. Kaplan-Meier survival curves were constructed and analyzed. The relationships between patient characteristics and responses to therapy and prognosis were evaluated. Main Results– Sixty-five records documented a diagnosis of SVT. Sixty-two percent were males. Labrador Retrievers and Boxers were overrepresented compared with the general hospital population. Median age at presentation was 9 years (range 0.5–15.5 y). The median heart rate during SVT was 270/minute (range 187–375/min). The most common presenting complaint was syncope (30%), 23% were asymptomatic at the time of diagnosis. Most dogs had structural heart disease (65%). Median survival was 472 days (<1–2007 d). Identification of sustained SVT (>30 s) did not affect survival ( P=0.50), nor did the presence of congestive heart failure ( P=0.70). Conclusions– The majority of dogs with SVT had structural heart disease or a severe concurrent illness at the time of SVT diagnosis. SVT, though often a persistent and occasionally sustained arrhythmia, does not appear to be a primary factor in mortality. [ABSTRACT FROM AUTHOR]

Objective: To characterize the relationship between clinical estimates of hydration in dogs and cats admitted to an intensive care unit (ICU) and changes in their body weight following 24-48 hours of fluid therapy. Design: Outcome study. Setting: ICU at a veterinary teaching hospital (VTH). Animals: A total of 151 dogs and 42 cats with various medical disorders that had not had surgery within 48 hours of admission into the ICU were consecutively admitted into the study. Animals with any condition predisposing to excess fluid loss or retention were excluded: heart disease, sepsis, trauma, pancreatitis, pleural or pericardial effusion, ascites, and pathologic oliguria. Animals that acquired any of the following during the observation period were excluded: gastrointestinal fluid loss, edema or diseases predisposing to edema, oliguria, diuretic therapy, and body fluid drainage or hemorrhage. Fluid therapy was ordered based on estimate of hydration at admission. Other treatments were not modified or withheld. Interventions: Physiologic data were collected at the time of admission and 24-48 hours later. Measurements and main results: Hydration was estimated on admission to the ICU using clinical judgement with no supporting laboratory data. Each admitting clinician used this estimate to plan fluid therapy. Fluid therapy was defined as the administration of any enteral or parenteral fluids as well as any decision to withhold fluids. Paired measurements taken on admission and at 24-48 hours included packed cell volume (PCV), total plasma solids (TS), and body weight. Amount and type of fluids or blood products administered were noted. Neither clinician estimates of dehydration nor baseline PCV or TS predicted clinically significant changes in body weight following fluid therapy, and there was no relationship between weight change and changes in PCV or TS. Conclusions: A clinical diagnosis of dehydration in our ICU does not predict weight gain following fluid therapy. Neither baseline PCV/TS nor changes in these measurements following 24-48 hours of fluid therapy predicted changes in body weight. [ABSTRACT FROM AUTHOR]

Objective: To characterize the indications and techniques for catheterization of the epidural space to treat pain in dogs and cats in a veterinary teaching hospital intensive care unit, and describe the analgesic regimens used in those patients. To provide a detailed description of the technique of epidural catheterization in companion animals. Design: Retrospective case series and clinical practice review. Setting: The Veterinary Teaching Hospital at the North Carolina State University College of Veterinary Medicine. Animals: Records from 160 dogs and 22 cats that had epidural catheters placed were identified. Interventions: Epidural catheterization for the purpose of providing analgesia for a variety of surgical and medical disorders was performed on both awake and anesthetized patients. Measurements and main results: The most frequently used analgesic agents were preservative-free morphine and bupivacaine. 2The range of duration of catheter dwell time was 1.3-332 hours, with a mean duration of 50 hours and a median of 39 hours. Suspicion of catheter malpositioning prompted radiographic imaging of the catheter in 44 patients, and malpositioning was confirmed in 6 of those. Catheter tip positioning was recorded in 46 patients. The tip was located at L3-L6 in 16, and T5-L3 in 30. Twenty-seven of those 30 patients were catheterized to treat pain associated with thoracotomy, forelimb amputation, pancreatitis, or peritonitis. Fifty-one (28%) patients received no analgesics beyond those provided by the epidural catheter. Conclusions: Epidural administration of analgesia appeared to provide significant pain relief and was adequate as a sole analgesic treatment in some patients. Serious complications in these critically ill animals appeared to be uncommon. ( J Vet Emerg Crit Care 2001; 11(2): 95-103) [ABSTRACT FROM AUTHOR]

The article presents several developments related to American College of Veterinary Emergency and Critical Care (ACVECC). ACVECC Research Grant Call For Pre-proposals is due on January 1, 2004. The date set for notification of invitation for submission of complete Proposal is February 15, 2004. Notification of funding will be presented in July 2004. The ACVECC congratulates the doctors, who passed the certifying exam to become ACVECC diplomats they include Soren Boysen of Quebec, Canada, Vicki Campbell of Fort Collins, Colorado, Steven Cole of Philadelphia, Pennsylvania Barbara Dallap of Landen berg, Pennsylvania and Elizabeth Dunphy of Mesa, Arizona.