Søren R. Boysen

Association between outcome and organ system dysfunction in dogs with sepsis: 114 cases (2003-2007)

OBJECTIVEnTo determine whether multiple organ dysfunction syndrome (MODS) could be identified in dogs with sepsis secondary to gastrointestinal tract leakage, and whether the number of affected organ systems was significantly associated with mortality rate.nnnDESIGNnMulticenter retrospective case series.nnnANIMALSn114 dogs.nnnPROCEDURESnMedical records for dogs treated surgically because of sepsis secondary to gastrointestinal tract leakage between 2003 and 2007 were reviewed. Sepsis was diagnosed on the basis of results of bacterial culture of peritoneal fluid, gross evidence of gastrointestinal tract leakage at surgery, or both. Renal dysfunction was defined as a > or = 0.5 mg/dL increase in serum creatinine concentration after surgery. Cardiovascular dysfunction was defined as hypotension requiring vasopressor treatment. Respiratory dysfunction was defined as a need for supplemental oxygen administration or mechanical ventilation. Hepatic dysfunction was defined as a serum bilirubin concentration > 0.5 mg/dL. Dysfunction of coagulation was defined as prolonged prothrombin time, prolonged partial thromboplastin time, or platelet count < or = 100,000/microL.nnnRESULTSn89 (78%) dogs had dysfunction of 1 or more organ systems, and 57 (50%) dogs had MODS. Mortality rate increased as the number of dysfunctional organ systems increased. Mortality rate was 70% (40/57) for dogs with MODS and 25% (14/57) for dogs without.nnnCONCLUSIONS AND CLINICAL RELEVANCEnResults indicated that MODS, defined as dysfunction of at least 2 organ systems, can be identified in dogs with sepsis and that organ system dysfunction increased the odds of death.

Thrombelastography in dogs admitted to an intensive care unit

BACKGROUNDnUnderlying conditions in dogs admitted to an intensive care unit (ICU) can cause hemostatic dysfunction. Thrombelastography (TEG) may be useful in detecting hemostatic alterations as compared with standard coagulation tests.nnnOBJECTIVESnThe purpose of this study was to compare TEG results and those of standard coagulation tests in identifying hemostatic dysfunction in dogs admitted to an ICU and to investigate associations among the variables measured.nnnMETHODSnTissue factor-activated TEG analysis, d-dimer and fibrinogen concentrations, antithrombin (AT) activity, prothrombin time (PT), activated partial thromboplastin time (aPTT), and platelet count were measured using standard techniques on 27 dogs admitted to ICU with a disease known to be associated with hemostatic dysfunction and in 31 clinically healthy control dogs. Results were compared between groups using nonparametric tests and kappa analysis; principal component analysis (PCA) and Spearman rank correlation were used to measure associations among variables.nnnRESULTSnFourteen of 27 ICU dogs had abnormal TEG tracings, which were used to classify the dogs as hypercoagulable (n=11), hypocoagulable (n=3), or normocoagulable (n=13). Hypercoagulable dogs had significantly increased d-dimer (P=.03) and fibrinogen (P=.01) concentrations compared with normocoagulable dogs. In ICU dogs, positive associations were identified between maximum amplitude (MA), alpha-angle, fibrinogen concentration, and platelet count, and between PT, aPTT, and reaction time (R). Significant correlations were found between MA and fibrinogen (r(s)=.76, P<.001) and between reaction time (R) and PT (r(s)=.51, P=.003).nnnCONCLUSIONSnTEG was useful in detecting hemostatic dysfunction in dogs in an ICU. Positive associations among variables may provide insight as to how overall coagulation status reflects alterations in clot strength and coagulation time. Dogs with TEG tracings indicative of hypercoagulability are likely in procoagulant states. Future studies of the incidence of thrombotic complications in dogs with hypercoagulable TEG tracings are warranted.

Management of acute renal failure in cats using peritoneal dialysis: a retrospective study of six cases (2003–2007)

Information regarding the use and success of peritoneal dialysis (PD) in the management of acute renal failure (ARF) in cats is lacking. The purpose of this retrospective study is to describe the indications, efficacy, complications and outcome of cats undergoing PD for ARF. Six cats that underwent PD for treatment of ARF of various etiologies were included. PD effectively replaced renal function in all cats and allowed renal recovery in 5/6 cats. Five cats were discharged and one cat died. Complications were reported in all cats and included subcutaneous edema (n=5), hyperglycemia (n=4), dialysate retention (n=3), and hypoalbuminemia (n=3). A novel technique consisting of a Blake surgical drain and an intermittent closed suction system was used, which appears to be a viable option for PD in cats. Although complications are common, PD is an effective renal replacement therapy for ARF in cats and carries a reasonable prognosis in selected cases.

Fluid and Electrolyte Therapy in Endocrine Disorders: Diabetes Mellitus and Hypoadrenocorticism

Diabetic ketoacidosis, hyperglycemic hyperosmolar syndrome, and acute adrenal crisis are life-threatening endocrine emergencies that have marked effects on fluid, electrolyte, and acid-base homeostasis. Rapid identification of these disorders and aggressive therapy to correct fluid, electrolyte, and acid-base imbalances are crucial to a successful outcome for the patient. An understanding of the pathophysiology behind the development of these endocrine disorders helps to guide therapy and improves the clinical outcome.

Respiratory Disease in Neonatal Cloned Calves

BACKGROUNDnNumerous clinical abnormalities occur in cloned calves during the neonatal period.nnnOBJECTIVESnDescribe respiratory diseases affecting cloned calves.nnnANIMALSnTwenty-five cloned Holstein calves.nnnMETHODSnRetrospective clinical study of the cloned calves born at the Veterinary Teaching Hospital, Saint-Hyacinthe, QC.nnnRESULTSnRecords of 31 cloned calves were reviewed. Twenty-five records were included. Four stillborn calves and 2 calves euthanized at birth were excluded. Twenty-two calves suffered from respiratory diseases. Nineteen calves received intranasal oxygen treatment (INO). They were tachypneic (78 breaths per minute) and 5 of them were hypoxemic (PaO₂ < 55 mmHg). Two of 19 calves remained hypoxemic despite INO. Thirteen calves were weaned from INO after a median of 70 hours and were discharged at a median of 5 days of age. Nine calves required ventilatory support: 3 from birth and 6 after INO. Five were successfully weaned from the ventilator after a median of 32 hours and were discharged at a median of 8 days of age. Three calves died and 1 was euthanized because of respiratory disease. Necropsy revealed atelectasis, pulmonary congestion, and alveolar damages.nnnCONCLUSION AND CLINICAL IMPORTANCEnRespiratory disease occurs frequently in cloned calves. The most frequent abnormality is hypoxemia because of V/Q mismatch. It is possible to successfully support these calves by INO and mechanical ventilation.

Evaluation of freshwater submersion in small animals: 28 cases (1996–2006)

OBJECTIVEnTo determine clinical characteristics, treatments, and outcome in dogs and cats evaluated after submersion in freshwater.nnnDESIGNnRetrospective case series.nnnANIMALSn25 dogs and 3 cats.nnnPROCEDURESnMedical records were reviewed for signalment; causes, location, and month of submersion; physical examination findings at admission; results of blood gas analysis; treatments administered; duration of hospitalization; and outcome, including evidence of organ failure or compromise.nnnRESULTSnAll submersions involved bodies of freshwater. Fourteen animals were submerged in man-made water sources, 13 were submerged in natural water sources, and the body of water was not recorded in 1 case. Twenty (71%) submersions occurred from May through September. Cause was identified in 16 animals and included extraordinary circumstances (n = 6), falling into water (5), breaking through ice (3), and intentional submersion (2). Twelve animals were found submerged in water with unclear surrounding circumstances. Treatment included administration of supplemental oxygen, antimicrobials, furosemide, corticosteroids, and aminophylline and assisted ventilation. Respiratory dysfunction was detected in 21 animals. Neurologic dysfunction was detected in 12 animals, hepatocellular compromise was detected in 6 animals, and cardiovascular dysfunction was detected in 4 animals. Three dogs had hematologic dysfunction, and 2 dogs had acute renal dysfunction. Eighteen (64%) animals survived to hospital discharge, but all of the cats died. In 9 of 10 nonsurvivors, respiratory tract failure was the cause of death or reason for euthanasia.nnnCONCLUSIONS AND CLINICAL RELEVANCEnResults suggest that submersion is an uncommon reason for veterinary evaluation but is associated with a good prognosis in dogs in the absence of respiratory tract failure.

Comparison of arterial and venous whole blood clot initiation, formation, and strength by thromboelastography in anesthetized swine

Thromboelastography (TEG) analysis was used to determine if differences exist between venous and arterial samples in anesthetized swine, using identical sampling techniques for each of the samples. We hypothesized that TEG parameters would not differ between native whole blood venous and arterial samples. Thirty male Landrace swines were included in the study. Both the femoral artery and vein were catheterized using standard cut-down techniques and with identically sized catheters to rule out any catheter size effects on the results. Standard TEG parameters for native whole venous and arterial blood samples (r, K, &agr;, MA, G, and coagulation index) were measured or calculated, and t-test or Mann–Whitney rank-sum test used for comparison when appropriate. Significant differences were detected for r (venous < arterial), K (venous < arterial), &agr; (venous > arterial), and coagulation index (venous > arterial) TEG parameters. No significant differences were measured for MA or G. These differences are important, especially when temporal changes in TEG are utilized to monitor patient stability and fluid therapy protocols using trends in coagulation properties. Taken together, these results suggest that clots are more likely to form at a faster rate in venous samples compared to arterial samples, but the overall clot strength does not differ. Therefore, if TEG analysis is being used to monitor coagulation profiles in a patient, care should be taken to use the same site and technique if results are to be used for comparative purposes.

COMPARISON OF THE EFFICACY AND SAFETY OF MEDETOMIDINE-KETAMINE VERSUS MEDETOMIDINE-AZAPERONE-ALFAXALONE COMBINATION IN FREE-RANGING ROCKY MOUNTAIN BIGHORN SHEEP (OVIS CANADENSIS)

Abstract Chemical immobilization is a key aspect of wildlife management. To minimize dose-dependent adverse effects, immobilization protocols often include two or more synergistic agents, which allows for reductions in individual drug dosages. Free-ranging bighorn sheep (Ovis canadensis) in Canada (n = 74) were remotely injected with a combination of medetomidine (0.16 ± 0.04 mg/kg) and ketamine (4.0 ± 1.4 mg/kg) (MK), or combination of medetomidine (0.14 ± 0.06 mg/kg), azaperone (0.21 ± 0.11 mg/kg), and alfaxalone (0.45 ± 0.21 mg/kg) (MAA). Once recumbency was achieved, arterial blood samples were collected and immediately analyzed for blood gas and acid-base status. Rectal temperature, heart rate, and respiratory rate were recorded upon recumbency and throughout anesthesia at 5–15 min intervals. At conclusion of the procedures, medetomidine was reversed by intramuscular atipamezole at five times the medetomidine dose. Induction times (mean ± standard deviation) of animals that became immobilized with one dart (8.7 ± 3.2 min, 7.3 ± 3.9 min) and recovery times of all animals (3.4 ± 1.5 min, 3.9 ± 1.6 min) were not significantly different between MK and MAA groups, respectively. Both MK and MAA groups experienced severe hypoxemia (PaO2 42 ± 9 mmHg, 40 ± 10 mmHg, respectively). PaCO2 was significantly higher (P = 0.0248) in the MK group (median 54 mmHg) than the MAA group (median 48 mmHg) with a trend towards lower pH (7.40 vs 7.42, respectively, P = 0.07). Initially, MK animals had higher heart rates than MAA animals (median 49 vs 40 beats/min), which decreased over time. In bighorn sheep, both MK and MAA produced reliable, reversible immobilization with smooth inductions and recoveries. However, less respiratory depression was seen with MAA than MK.