Association of hyperlactatemia with age,diagnosis, and survival in equine neonates

Objective – To investigate the association between blood lactate concentration, measured at admission and following 12–36 hours of treatment, and age, diagnosis, and survival in neonatal foals. Design – Retrospective, observational study. Setting – Two equine referral hospitals. Animals – One hundred and twelve foals ≤96 hours of age were included. Interventions – Arterial or venous blood samples were obtained from all foals at admission and surviving foals at 12–36 hours. Measurements – The lactate concentration (LAC) was recorded at 2 time points: admission (LAC‐Admission) and 12–36 hours following treatment (LAC‐24 hours). Main Results – LAC decreased by 0.05 mmol/L for each increased hour of age at presentation. Premature/dysmature foals demonstrated increased odds of nonsurvival of 55% for each 1 mmol/L increase in LAC‐Admission while foals with major diagnoses of neonatal encephalopathy (NE), enteritis and ‘Other’ had increased odds of nonsurvival of 52%, 113%, and 247%, respectively, for each 1.0 mmol/L increase in LAC. Blood‐culture positive foals had significantly lower LAC than blood culture negative foals. LAC‐Admission and LAC‐24 hours were significantly larger in nonsurviving foals. LAC‐Admission of >6.9 mmol/L and LAC‐24 hours >3.2 mmol/L, respectively, correctly classified 85.6% and 94.1% of cases as survivors or nonsurvivors. No differences were found when the 24‐hour change in LAC was investigated in terms of outcome, age at admission, or major diagnosis; however, LAC‐24 hours remained significantly associated with survival. Conclusions – Admission or persistent hyperlactatemia is associated with a nonsurvival. Younger foals, premature/dysmature foals, and foals with neonatal encephalopathy had the largest LAC.     

Blood glucose concentrations in critically ill neonatal foals

Reasons for Performing Study: Critical illness is associated with hyperglycemia in humans, and a greater degree and duration of hyperglycemia is associated with nonsurvival. Hypoglycemia is also seen in critically ill humans, and is associated with nonsurvival. This might also be true in the critically ill foal.
Objectives: To investigate the association of blood glucose concentrations with survival, sepsis, and the systemic inflammatory response syndrome (SIRS).
Methods: Blood glucose concentrations at admission (515 foals) and 24 hours (159 foals), 36 hours (95), 48 hours (82), and 60 hours (45) after admission were analyzed. Logistic regression analyses were performed to investigate the association of glucose concentrations with survival, sepsis, a positive blood culture, or SIRS.
Results: 29.1% of foals had blood glucose concentrations within the reference range (76–131 mg/dL) at admission, 36.5% were hyperglycemic, and 34.4% were hypoglycaemic. Foals that did not survive to hospital discharge had lower mean blood glucose concentrations at admission, as well as higher maximum and lower minimum blood glucose concentrations in the 1st 24 hours of hospitalization, and higher blood glucose at 24 and 36 hours. Foals with blood glucose concentrations <2.8 mmol/L (50 mg/dL) or >10 mmol/L (180 mg/dL) at admission were less likely to survive. Hypoglycemia at admission was associated with sepsis, a positive blood culture, and SIRS.
Conclusions and Potential Relevance: Derangements of blood glucose concentration are common in critically ill foals. Controlling blood glucose concentrations may therefore be beneficial in the critically ill neonatal foal, and this warrants further investigation.     

Association of Blood Lactate Concentration and Outcome in Foals

Background: Lactate concentration in blood or plasma ([LAC]) and change in [LAC] are associated with survival in sick foals. Hypothesis: [LAC] and change in [LAC] over time are associated with survival at 96 hours and discharge in neonatal foals. Furthermore [LAC] and change in [LAC] over time correlate with blood culture results and blood pressure at admission. Animals: Two hundred and twenty‐five foals consecutively admitted to a Neonatal Intensive Care Unit. Methods: Retrospective case review. Foals ≤30 days of age with [LAC] from arterial (190) or umbilical (35) blood gas analysis ([LAC]_BG) at admission, 24, and 48 hours. [LAC]_BG, blood pressure, blood culture status, and outcome (survival versus nonsurvival at 96 hours and discharge) were recorded. Change in [LAC]_BG over time ([LAC]_BGΔT) was calculated. Results: [LAC]_BG was lower in survivors (96 hours and discharge) at all times. [LAC]_BGΔT was larger for survivors (96 hours). Odds of survival (96 hours and discharge) decreased 18, 39, 53 and 22, 38, and 47%, respectively, at each sample time for every 1 mmol/L increment in [LAC]_BG and increased 156% for each 1.0/day increment in [LAC]_BGΔT from admission to 24 hours at 96 hours. Blood pressure and [LAC]_BG were not correlated (P= .196) until removal of selected foals (mean arterial pressure <60 mmHg, admission [LAC]_BG <5.5 mmol/L) (P < .001). Bacteremia was not associated with [LAC]_BG. Proposed admission [LAC]_BG cut‐points for future studies were 6.5 mmol/L (96 hours) and 5.5 mmol/L (discharge). Conclusions and Clinical Importance: Prospective studies evaluating [LAC], [LAC]_BGΔT, and cut‐points in sick foals are warranted.     

Pharmacokinetics of an orally administered methylcellulose formulation of gallium maltolate in neonatal foals

Chaffin, M. K., Fajt, V., Martens, R. J., Arnold, C. E., Cohen, N. D., O’Conor, M., Taylor, R. J., Bernstein, L. R. Pharmacokinetics of an orally administered methylcellulose formulation of gallium maltolate in neonatal foals. J. vet. Pharmacol. Therap. doi: 10.1111/j.1365‐2885.2009.01150.x. Gallium is a trivalent semi‐metal with anti‐microbial effects because of its incorporation into crucial iron‐dependent reproductive enzyme systems. Gallium maltolate (GaM) provides significant gallium bioavailability to people and mice following oral administration and to neonatal foals following intragastric administration. To study the prophylactic and therapeutic effects of GaM against Rhodococcus equi pneumonia in foals, we developed a methylcellulose formulation of GaM (GaM‐MCF) for oral administration to neonatal foals. Normal neonatal foals were studied. Six foals received 20 mg/kg and another six foals received 40 mg/kg of GaM‐MCF orally. Serial serum samples were collected and serum gallium concentrations were determined using inductively coupled plasma mass spectroscopy. Gallium was rapidly absorbed (T_max of 4 h), and a mean C_max of 0.90 or 1.8 μg/mL was achieved in foals receiving 20 or 40 mg/kg respectively. Marked variability existed in C_max among foals: only half of the foals receiving 20 mg/kg attained serum concentrations of >0.7 μg/mL, a level suggested to be therapeutic against R. equi by previous studies. Mean elimination half‐life was 32.8 or 32.4 h for foals receiving 20 or 40 mg/kg respectively. The results of this study suggest that at least 30 mg/kg orally every 24 h should be considered in future pharmacodynamic and efficacy studies.     

Risk factors and prognostic variables for survival of foals with radiographic evidence of pulmonary disease

The medical records of 163 neonatal foals that had thoracic radiographs taken within 48 hours of admission to a referral hospital were reviewed. The objectives of this study were (1) to identify risk factors for the development of thoracic radiographic changes and (2) to identify prognostic indicators for survival in foals with radiographic evidence of pulmonary disease. Failure of transfer of passive immunity (IgG concentration < or = 400 mg/dL) was the only risk factor for radiographic evidence of respiratory disease identified by multivariate analysis. Hypoxemic patients (PaO2 < or = 60 mm Hg) were 4.9 times more likely to reveal radiographic abnormalities in a subset of foals for which arterial blood gas results were available. Foals with a serum creatinine concentration > 1.7 mg/dL upon presentation, dyspnea, and a history of dystocia were significantly more likely to die based on the multivariate statistical outcome analysis. An anion gap > or = 20 mEq/dL was strongly associated with nonsurvival in a subset of foals with arterial blood gas results. These hematologic and biochemical variables can be readily obtained during the initial evaluation of sick foals. The presence of a high anion gap appeared to have the greatest clinical impact and may be a useful prognostic indicator in foals with radiographic evidence of respiratory disease. In contrast, the majority of physical examination variables, including evaluation of tachypnea, abnormal respiratory sounds, fever, weakness, and milk reflux from the nares, which are usually obtained during the general respiratory evaluation of foals, were unrelated to outcome.     

Factors Associated with Survival in Septicemic Foals: 65 Cases (1988–1995)

In order to identify variables obtained at admission that could be used to predict survival in septicemic foals, medical records of 65 foals diagnosed with septicemia were reviewed. Initially, variables were analyzed independently (univariate analysis) for association with survival. Of the physical examination and historical data examined using univariate analysis, the ability to stand at admission, respiratory rate ≥ 60 breaths per minute (bpm), and normal-appearing mucous membranes were significantly associated with survival. Foals with history of induced parturition were significantly less likely to survive. The following hematologic and serum biochemical variables determined at admission were significantly associated with survival: white blood cell count a 6,000 cells/μL, neutrophil count <4,000 cells/μL, serum albumin concentration <2.2 g/dL, serum glucose concentration <120 mg/ dL, blood pH ≥ 7.35, and positive base excess. The administration of plasma at admission was significantly associated with survival. Stepwise multiple logistic regression analysis was performed to evaluate the association between survival and variables identified as significantly associated with survival in bivariate analysis. The final multivariate model selected included the variables standing, duration of clinical signs (24-hour intervals) prior to admission, respiratory rate a 60 bpm, neutropenia (> 4,000 cells/μL), and neonatal age category. The probability of survival was significantly increased for foals that were standing, had a respiratory rate a 60 bpm, and that had a neutrophil count <4,000 cells/μL at admission. Probability of survival was significantly decreased for foals that had a longer duration of clinical signs prior to admission. For each 24 hours of duration, the estimated risk of death was increased by 5.8-fold.     

Measurement of plasma colloid osmotic pressure in neonatal foals under intensive care: comparison of direct and indirect methods and the association of COP with selected clinical and clinicopathologic variables

Objectives: To describe and compare admission colloid osmotic pressure (COP) measurement using both direct and indirect methods in neonatal foals under intensive care, and to evaluate for associations between COP and clinical/clinicopathologic parameters. Design: Prospective study. Setting: Intensive care unit at a veterinary medical teaching hospital. Animals: Twenty‐six critically ill neonatal foals were studied. A control group consisted of 9 clinically healthy neonatal foals. Interventions: Clinicopathologic data were collected at the time of admission. COP was measured directly using a colloid osmometer. Indirect COP was calculated using equations by both Landis–Pappenheimer (L–P) and Thomas and Brown. Measurements and main results: Measured admission COP values were 17.1±4.3 and 17.7±2.4 mmHg in critically ill and control foals, respectively, and these values were not significantly different. Critically ill foals with blood lactate concentrations >3 mmol/L had lower COP values than those with lactate ≤3 mmol/L. There was close agreement between indirect COP values calculated using the L–P equation and direct COP values measured in control foals (mean error=0.0±1.3 mmHg; R²=0.87). However, indirect values were not as predictive of direct COP in critically ill foals (mean error=0.8±3.8 mmHg; R²=0.64). As COP values increased, the indirect method tended to overestimate COP, whereas at lower values it slightly underestimated COP. Conclusion: While the L–P equation was a close approximation of direct COP in healthy foals, direct measurements of oncotic pressure cannot be replaced for monitoring of critically ill foals. Critically ill foals with higher lactate concentrations had lower COP values, suggesting a possible relationship between COP and lactate.     

Sequential Plasma Lactate Concentrations as Prognostic Indicators in Adult Equine Emergencies

Background: Sequential lactate concentration ([LAC]) measurements have prognostic value in that hospitalized humans and neonatal foals that have a delayed return to normolactatemia have greater morbidity and case fatality rate.
Hypothesis: Prognosis for survival is decreased in horses with a delayed return to normal [LAC].
Animals: Two hundred and fifty adult horses presented for emergency evaluation excepting horses evaluated because of only ophthalmologic conditions, superficial wounds, and septic synovitis without systemic involvement.
Methods: Prospective observational study. [LAC] was measured at admission and then at 6, 12, 24, 48, and 72 hours after admission. The change in [LAC] over time ([LAC]Δ T ) was calculated from changes in [LAC] between sampling points.
Results: Median [LAC] was significantly ( P < .001) higher at admission in nonsurvivors (4.10 mmol/L [range, 0.60–18.20 mmol/L]) when compared with survivors (1.30 mmol/L [range, 0.30–13.90 mmol/L]) and this difference remained at all subsequent time points. The odds ratio for nonsurvival increased from 1.29 (95% confidence interval 1.17–1.43) at admission to 49.90 (6.47–384) at 72 hours after admission for every 1 mmol/L increase in [LAC]. [LAC]Δ T was initially positive in all horses but became negative and significantly lower in nonsurvivors for the time periods between 24–72 hours (− 0.47, P = .001) and 48–72 hours (− 0.07, P = .032) when compared with survivors (0.00 at both time periods) consistent with lactate accumulation in nonsurvivors.
Conclusions and Clinical Importance: These results indicate that lactate metabolism is impaired in critically ill horses and [LAC]Δ T can be a useful prognostic indicator in horses.     

Serum free cortisol fraction in healthy and septic neonatal foals

Background: Relative cortisol insufficiency occurs in septic foals and impacts survival. Serum free (biologically available) cortisol concentration might be a better indicator of physiologic cortisol status than serum total cortisol concentration in foals. Hypotheses: In septic foals, (1) low free cortisol concentration correlates with disease severity and survival and (2) predicts disease severity and outcome better than total cortisol concentration. Animals: Fifty‐one septic foals; 11 healthy foals; 6 healthy horses. Methods: In this prospective clinical study, foals meeting criteria for sepsis at admission were enrolled. University‐owned animals served as healthy controls. Basal and cosyntropin‐stimulated total cortisol concentration and percent free cortisol (% free cortisol) were determined by chemiluminescent immunoassay and ultrafiltration/ligand‐binding methods, respectively. Group data were compared by ANOVA, Mann‐Whitney U‐tests, and receiver operator characteristic curves. Significance was set at P < .05. Results: Basal % free cortisol was highest in healthy foals at birth (58±8% mean±SD), and was higher (P≤.004) in healthy foals of all ages (33±6 to 58±8%) than in adult horses (7±3%). Cosyntropin‐stimulated total and free cortisol concentrations were lower (P≤.03) in foals with shock (total = 6.2±8.1 μg/dL; free = 3.5±4.8 μg/dL versus total = 10.8±6.0 μg/dL; free = 6.9±3.3 μg/dL in foals without shock) and in nonsurvivors (total = 3.8±6.9 μg/dL; free = 1.9±3.9 μg/dL versus total = 9.1±7.7 μg/dL; free = 5.5±4.4 μg/dL in survivors). Free cortisol was no better than total cortisol at predicting disease severity or outcome in septic foals. Conclusions and Clinical Importance: Serum free cortisol is impacted by age and illness in the horse. There is no advantage to measuring free over total cortisol in septic foals.     

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

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 <72‐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 P<0.05 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=0.02). Foals with prolonged ACT (P=0.03), and decreased CR at admission (P=0.047), were more commonly coagulopathic. Identification of coagulopathy on admission (P=0.02), or persistence of hemostatic dysfunction 48 hours later (P=0.04), 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.     

Parenteral nutrition in neonatal foals: clinical description, complications and outcome in 53 foals (1995-2005)

This retrospective study describes the use of and complications associated with parenteral nutrition (PN) administration to 53 equine neonates at the University of California Veterinary Medical Teaching Hospital. Medical records were examined and information obtained on signalment, physical examination, clinical diagnosis, outcome, total hospitalization time, insulin administration, microbiology culture results, other complications (i.e. thrombophlebitis) and necropsy findings. Complete blood count and serum biochemistry analytes, venous blood gas, serum electrolyte and glucose concentrations, and blood lactate concentration results were compared before and during PN administration in all foals. Seventeen foals (32%) developed hypertriglyceridemia (>200mg/dL). Triglyceride concentrations >200mg/dL were significantly (P=0.049) associated with non-survival. Forty-seven foals (89%) developed hyperglycemia (blood glucose >120mg/dL) and eight (15%) developed catheter-related complications (thrombosis or local sepsis). Packed cell volume, total protein, creatinine, blood urea nitrogen, and sorbitol dehydrogenase concentrations decreased while foals were on PN, while serum chloride concentration increased. This study highlighted that hypertriglyceridemia during the acute phase of neonatal illness may be detrimental to outcome, and that the safety of lipid-containing solutions in foals warrants further study.     

Refractometric total plasma protein measurement as a cage‐side indicator of hypoalbuminemia and hypoproteinemia in hospitalized dogs

Objective – To assess the relationship between total plasma protein (TPP) as measured by refractometry and serum hypoalbuminemia and hypoproteinemia in hospitalized dogs. Design – Retrospective, observational study conducted over 6‐month period between March and August 2008. Setting – University teaching hospital. Animals – Four hundred and three hospitalized dogs in an ICU. Interventions – None. Measurements and Main Results – TPP, serum albumin, total protein, glucose, urea, cholesterol was measured from dogs enrolled in study. TPP was evaluated as a predictor for hypoalbuminemia defined both as albumin <25 g/L (<2.5 g/dL) and albumin <20 g/L (<2.0 g/dL), and serum hypoproteinemia, defined as serum total protein <40 g/L (<4.0 g/dL), using logistic regression. Impact of glucose, urea, cholesterol, and total bilirubin on refractometric readings were also assessed. TPP predicted hypoalbuminemia at albumin concentrations of <25 g/L (<2.5 g/dL) and <20 g/L (<2.0 g/dL) (P<0.001). A TPP<60 g/L (<6.0 g/dL) predicted albumin <25 g/L (<2.5 g/dL) with 73% sensitivity and 86% specificity. A TPP<58 g/L (<5.8 g/dL) predicted a serum albumin <20 g/L (<2.0 g/dL) with 70% sensitivity and 80% specificity. For dogs with known risk factors where specificity optimization may be appropriate, refractometer TPP<50 g/L (<5.0 g/dL) and <48 g/L (<4.8 g/dL) predicted hypoalbuminemia at each level with >95% specificity, although sensitivity was poor. Refractometer TPP<58 g/L (<5.8 g/dL) predicted serum total protein of <40 g/L (<40 g/dL) with sensitivity of 82% and specificity of 84%. Hypercholesterolemia and hyperglycemia significantly affected TPP readings; an increase in serum glucose by 10 mmol/L (180 mg/dL) was associated with an average independent increase in refractometer TPP of 2.27 g/L (0.23 g/dL) (P<0.001, 95% confidence interval=1.08–3.47) and an increase in serum cholesterol of 1 mmol/L (38.6 mg/dL) was associated with an average independent increase in refractometer TPP of 1.36 g/L (0.14 g/dL) (P<0.001, 95% confidence interval=1.12–1.59). Conclusion – Suboptimal sensitivity limits the use of refractometric TPP for prediction of hypoalbuminemia in the context of patient screening; a high proportion of false negatives may result. However, identification of a refractometric TPP<58 g/L is strongly indicative of both serum hypoalbuminemia and hypoproteinemia, with high specificity, and warrants further investigation. Refractometric readings may be falsely increased in patients with hyperglycemia or hypercholesterolemia.     

Administration of RRR‐α‐tocopherol to pregnant mares stimulates maternal IgG and IgM production in colostrum and enhances vitamin E and IgM status in foals

This study assessed the effect of a vitamin E supplement given to pregnant mares on immunoglobulins (Ig) levels in foals. In addition, the fatty acid (FA) content and composition of the mares’ milk was assessed. Milk α‐tocopherol concentrations were compared between pregnant Danish Warmblood mares (n = 17) given a daily oral supplement of 2500 international units (IU) RRR‐α‐tocopherol in the last 4 weeks of pregnancy and a group of unsupplemented mares (n = 17) receiving 170–320 IU vitamin E daily originating from the feed. Milk α‐tocopherol was higher in supplemented mares (36.7, 12.4 and 9.8 μmol/l respectively) in relation to control mares (13.1, 6.4 and 5.8 μmol/l on days 1, 2 and 3 respectively; p < 0.001). Milk IgG was higher on days 2 and 3 post‐partum (PP) in supplemented mares (1.03 and 0.73 mg/ml respectively) in relation to control mares (0.79 and 0.56 mg/ml respectively; p < 0.05). Milk IgM was higher on days 2 and 3 post‐partum (PP) in supplemented mares (0.19 and 0.17 mg/ml) in relation to control mares (0.13 and 0.11 mg/ml respectively; p < 0.05). Plasma α‐tocopherol in foals was higher from supplemented mares on days 1, 2 and 3 (5.7, 14.8 and 19.2 μmol/l respectively) in relation to foals from control mares (3.6, 6.1 and 7.6 respectively; p < 0.001). Foal plasma IgM was higher from supplemented mares on day 3 (0.50 mg/ml) in relation to foals from control mares (0.32 mg/ml; p < 0.001). The total FA content in milk was highest on day 1 (21.6 g FA/kg milk) in relation to days 2 and 3 (13.6 and 13.5 g FA/kg milk respectively; p < 0.001). In conclusion, a daily oral supplement of 2500 IU RRR‐α‐tocopherol increased α‐tocopherol content in mare milk and foal plasma, IgG and IgM in mare milk and IgM in foal plasma.     

Antithrombin: Could It be a Diagnostic and Prognostic Marker in Septic Neonatal Foals?

Antithrombin (AT) levels are lower in human neonates affected by sepsis and in nonsurvivors compared with survivors. The aims of this study were to evaluate AT profile in healthy newborn foals and its diagnostic and prognostic role in septic foals during the first week of life. Fifteen healthy foals and 35 septic foals were enrolled. Blood samples were collected from each healthy foal at 30 minutes, 3 and 12 hours from birth, daily from days 1–7, and at days 10 and 14. Blood was collected from each septic foal twice a day from admission to discharge or death. The AT analysis was performed by chromogenic method. Healthy foals showed decreasing levels of AT between 3 hours and 2 days, followed by an increasing trend. Septic foals did not show any difference during the period of observation, and no differences were found between healthy and septic age-matched foals. The analysis of AT activity on the day of admission in septic foals showed higher levels compared with healthy foals, in animals hospitalized at 12 and 24 hours of age (P < .01). No differences were found at admission between foals affected by sepsis and that with septic shock. Nonsurviving foals showed significantly lower levels at 3 and 4 days of age compared with surviving foals; when surviving and nonsurviving foals were compared independently by the age, nonsurviving foals showed significant (P < .05) lower levels 12 hours after admission. In conclusion, AT seems to show neither a diagnostic nor a prognostic role in septic neonatal foals.     

Comparison of continuous infusion with intermittent bolus administration of cefotaxime on blood and cavity fluid drug concentrations in neonatal foals

Hewson, J., Johnson, R., Arroyo, L. G., Diaz‐Mendez, A., Ruiz‐López, J. A., Gu, Y., del Castillo, J. R. E. Comparison of continuous infusion with intermittent bolus administration of cefotaxime on blood and cavity fluid drug concentrations in neonatal foals. J. vet. Pharmacol. Therap.  36 , 68–77. Healthy neonatal foals were treated with cefotaxime by bolus (40 mg/kg IV q6h for 12 doses; n = 10) or by infusion (loading dose of 40 mg/kg IV followed by continuous infusion of a total daily dose of 160 mg/kg per 24 h for 3 days; n = 5). Population pharmacokinetics was determined, and concentrations in cavity fluids were measured at steady state (72 h). Highest measured serum drug concentration in the bolus group was 88.09 μg/mL and minimum drug concentration (C_min) was 0.78 μg/mL at 6‐h postadministration (immediately before each next dose), whereas infusion resulted in a steady‐state concentration of 16.10 μg/mL in the infusion group. Mean cefotaxime concentration in joint fluid at 72 h was higher (P = 0.051) in the infusion group (5.02 μg/mL) compared to the bolus group (0.78 μg/mL). Drug concentration in CSF at 72 h was not different between groups (P = 0.243) and was substantially lower than serum concentrations in either group. Insufficient data on pulmonary epithelial lining fluid were available to compare the methods of administration for cefotaxime in this cavity fluid. Results support continuous drug infusion over bolus dosing in the treatment for neonatal foal septicemia to optimize time that cefotaxime concentration exceeds the minimum inhibitory concentration of common equine pathogens.     

Use of continuous renal replacement therapy for treatment of dogs and cats with acute or acute-on-chronic renal failure: 33 cases (2002–2006)

Objective: To describe the indications, clinical features, outcomes and complications associated with use of continuous renal replacement therapy (CRRT) in 17 client-owned dogs and 16 client-owned cats with acute or acute-on-chronic renal failure refractory to aggressive medical management.
Series summary: Twenty-nine percent of dogs and 44% of cats had evidence of pre-existing chronic kidney disease (CKD). Median duration of CRRT was 16.3 hours (range 0.3–83.0 hours) in dogs and 11.5 hours (range 1.0–35.5 hours) in cats. Median canine blood urea nitrogen (BUN) improved from 41.0 mmol/L (115.0 mg/dL) to 11.8 mmol/L (33.0 mg/dL) and creatinine from 636.5 mmol/L (7.2 mg/dL) to 274 mmol/L (3.1 mg/dL). Median feline BUN improved from 46.4 mmol/L (130 mg/dL) to 13.9 mmol/L (39.0 mg/dL) and creatinine from 1069.6 mmol/L (12.1 mg/dL) to 291.7 mmol/L (3.3 mg/dL). Metabolic acidosis resolved in 80% of affected dogs and 71% of affected cats. Hyperkalemia resolved in 100% of affected dogs and 88% of affected cats. Complications noted with CRRT included iatrogenic hypokalemia, iatrogenic metabolic alkalosis, clinical hypocalcemia, total hypercalcemia, filter clotting, anemia, hypothermia, and neurologic complications. Forty-one percent of dogs and 44% of cats survived to discharge. No dogs and only 1 cat developed newly diagnosed CKD.
New or unique information provided: CRRT can be a viable option for the management of acute or acute-on-chronic renal failure in dogs and cats that are refractory to aggressive medical management. The frequency of complications associated with CRRT in this study warrants further experience with this modality before its widespread use can be recommended.     

Retrospective Study: Incidence of transfusion reactions to commercial equine plasma

Objective – To report on the incidence of transfusion reactions to commercial equine plasma in a hospital‐based population of horses, to characterize these reactions and report on outcome. Design – Retrospective study. Setting – University teaching hospital. Animals – Client‐owned horses referred to the University of Wisconsin. Interventions – Intravenous administration of 2 commercial equine plasma products when clinically indicated. Measurements and Main Results – Medical records of 107 horses that received plasma transfusions between 2003 and 2008 were evaluated. Transfusion reactions were recorded in 6 of 107 transfusions. All individuals were administered plasma from 1 commercial source. Foals <30 days of age received a hypergammaglobulinemic product and all adults received a lower IgG concentration product. No reactions were recorded in adults. In foals (<30 d) reactions were recorded in 6 of 69 cases (8.7%), all of which occurred in neonates <7 days of age (6/62; [9.7%]). The most frequent reactions were fever (4/6), tachycardia (2/6), tachypnea (2/6), and colic (2/6). All affected foals survived the reaction. There were no statistically significant differences (P<0.05) in any of the variables examined between those foals that did and those that did not experience transfusion reactions. Conclusion – The incidence of transfusion reactions was 8.7% in foals and 0% in adult horses in our referral population. Five of 6 foals responded to medical therapy and eventually received the clinically indicated transfusion. No transfusion related mortality occurred.     

Pelvic fracture triggering symptoms of an underlying primary hypoparathyroidism in an adult spayed bitch: A case report

A 7-year-old mixed breed spayed bitch (body weight: 10.6 kg) was presented with a history of intermittent episodes of seizures and untreated limb fracture. Appetite loss, nervousness, lateral recumbency, fasciculations, ataxia and poor nutritional condition were found. Venous blood gas analysis highlighted normal acid-base balance and severe low ionized calcium (0.58 mEq/L [range 1.13–1.32 mEq/L]). Marked total hypocalcaemia (6.4 mg/dL [range 8–10] or 1.6 mM [range: 2–2.5]) associated with hyperphosphoraemia (9.3 mg/dl [range 3.5–6.5 mg/dl]) displayed inverted ratio between minerals. ECG showed sinus arrhythmias. Circulating levels of Mg and Cu were within physiological range (1.97 mg/dl and 128 μg/dl respectively) and effects from interactions were excluded. Oral administration of calcitriol at 40 ng/kg/day led to clinical improvement within 48 hours, but circulating iCa levels were still below the lower limit of the reference range. Baseline levels of circulating parathormone (PTH) were 3 pg/ml, along with normal values of circulating vitamin D. Primary hypoparathyroidism was diagnosed as a chronic underlying condition triggered by pelvic fracture.     

Retrospective Study: The association of blood lactate concentration with outcome in dogs with idiopathic immune‐mediated hemolytic anemia: 173 cases (2003–2006)

Objective – To determine the association of blood lactate with outcome and response to transfusion therapy in dogs with idiopathic immune‐mediated hemolytic anemia (IMHA). Design – Retrospective study. Setting – Urban veterinary small animal emergency hospital. Animals – One hundred and seventy‐three client‐owned dogs with IMHA. Interventions – None. Measurements and Main Results – Serial blood lactate concentration, therapeutic interventions, and outcome were recorded. Nonsurvivors were defined as those that died or were euthanized. One hundred and thirty‐three dogs (77%) survived, 35 (20%) were euthanized, and 5 (3%) died. One hundred forty‐five dogs (84%; 145/173) had a lactate concentration above the laboratory reference interval [0.46–2.31 mmol/L] on presentation. Blood lactate at presentation was higher in the nonsurvivors (median 4.8 mmol/L; 0.5–13.6) compared with survivors (median 2.9 mmol/L; 0.3–13.2) (P<0.01). All dogs presenting with hyperlactatemia that normalized (<2.0 mmol/L) within 6 hours of admission survived, whereas, 71% of dogs that had a persistent hyperlactatemia at 6 hours survived (P=0.034). Lactate was positively correlated with age, BUN, and alkaline phosphatase, and inversely correlated with PCV. Receiver operating curve analysis for lactate concentration at admission as a test for outcome had an area under the curve of 0.69 with an optimal lactate cutoff concentration of 4.4 mmol/L correctly predicting outcome 73% of the time (sensitivity 60%, specificity 77%). Conclusions – Lactate concentration at presentation was significantly higher in nonsurvivors than survivors. Lactate was significantly correlated with previously reported outcome variables but lactate concentration at admission, as a predictor for outcome was less than optimal. However, serial lactate concentration measurements may be more predictive as patients with persistent hyperlactatemia 6 hours after admission were less likely to survive. Prospective studies evaluating serial lactate concentration while controlling for other variables may provide further insight into lactate measurement as a prognostic indicator in animals with IMHA.