Blood Glucose in Horses with Acute Abdominal Disease

Use of multiple admission variables better predicts intestinal strangulation in horses with colic than peritoneal or the ratio of peritoneal:blood l-lactate concentration

BACKGROUND

Early identification of strangulating obstruction (SO) in horses with colic improves outcomes, yet early diagnosis of horses requiring surgery for SO often remains challenging.

OBJECTIVES

To compare blood and peritoneal fluid l-lactate concentrations, peritoneal:blood l-lactate ratio, peritoneal minus blood (peritoneal-blood) l-lactate concentration and other clinical variables for predicting SO and SO in horses with small intestinal lesions (SO-SI) and then to develop a multivariable model to predict SO and SO-SI.

STUDY DESIGN

Retrospective cohort.

METHODS

A total of 197 equids admitted to a referral institution for colic between 2016 and 2019 that had peritoneal fluid analysis performed at admission were included. Twenty-three admission variables were evaluated individually for the prediction of a SO or SO-SI and then using multivariable logistic regression. Odds ratios (ORs) with 95% confidence intervals (CI) and area under the curve of the receiver operator characteristic (AUC ROC) were calculated.

RESULTS

All variables performed better in the model than individually. The final multivariable model for predicting SO included marked abdominal pain (OR 5.31, CI 1.40-20.18), rectal temperature (OR 0.30, CI 0.14-0.64), serosanguineous peritoneal fluid (OR 35.34, CI 10.10-122.94), peritoneal-blood l-lactate (OR 1.77, CI 1.25-2.51), and peritoneal:blood l-lactate ratio (OR 0.36, CI 0.18-0.72). The AUC ROC was 0.91. The final multivariable model for predicting SO-SI included reflux volume (OR 0.69, CI 0.56-0.86), blood l-lactate concentration (OR 0.43, CI 0.22-0.87), serosanguineous peritoneal fluid (OR 4.99, CI 1.26-19.74), and peritoneal l-lactate concentration (OR 3.77, CI 1.82-7.81).

MAIN LIMITATIONS

Retrospective, single-hospital study design.

CONCLUSIONS

Blood and peritoneal fluid l-lactate concentrations should be interpreted in conjunction with other clinical variables. The relationship between peritoneal and blood l-lactate concentration for predicting SO or SO-SI was complex when included in a multivariable model. Models to predict SO probably vary based on lesion location.

Radiological and laboratory prognostic parameters for gastric dilation in rabbits (Oryctolagus cuniculus)

BACKGROUND

The aim of this study was to evaluate the radiographical and laboratory findings in pet rabbits with gastric dilation (GD) and identify prognostic parameters.

METHODS

One hundred and fifty-five rabbits with GD were included for the radiographical analyses and 75 for the laboratory analyses. A vertebral stomach score (VSS) was established to determine the extension of the stomach on lateral radiographs. In addition, the caudal limit of gastric distention and the extension and position of gas accumulation in the stomach were recorded.

RESULTS

The VSS was significantly higher in rabbits with GD than in healthy rabbits (p = 0.001). Extensive amounts of gas accumulation in the stomach (p = 0.001) and a ventral or central location of gas accumulation (p = 0.023) were associated with significantly increased mortality. Azotemia (51%), hyperglycaemia (44%) and hyponatraemia (37%) were the most frequent biochemical alterations in rabbits with GD.

LIMITATIONS

Due to the retrospective nature of the data, the cause of GD could not be determined in all animals.

CONCLUSION

Rabbits with GD and severe alterations in glucose, creatinine and sodium concentrations, ventral or central gas accumulations and a large amount of gas in the stomach had a poor prognosis.

Basic Postoperative Care of the Equine Colic Patient

The 3 time periods around colic surgery (preoperative, operative, and postoperative) are all critical to successful outcomes. Although much focus is often paid to the first 2 time periods, the importance of sound clinical judgment and rational decision-making in the postoperative period cannot be overstated. This article will outline the basic principles of monitoring, fluid therapy, antimicrobial therapy, analgesia, nutrition, and other therapeutics routinely used in patients following colic surgery. Discussions of the economics of colic surgery and expectations for normal return to function will also be included.

Early Identification of Intestinal Strangulation: Why It Is Important and How to Make an Early Diagnosis

Horses with colic caused by intestinal strangulation can have an excellent outcome with early surgical correction of the obstruction. The expense associated with surgery is typically less with early lesion correction. The challenge is making an early diagnosis of intestinal strangulation. Although for some horses with a strangulating obstruction, the need for surgery is made based on severe colic signs or lack of response to analgesia, in other horses, it is less obvious. Signalment, history, and meticulous physical examination, combined with some targeted diagnostic procedures can help with early diagnosis of intestinal strangulation. Improving the outcome of these horses requires diligence and a team-based approach from the owner or caregiver, primary care veterinarian, and specialists.

Metabolomic Profiles in Starved Light Breed Horses during the Refeeding Process

The large population of emaciated horses continues to be an issue troubling the equine industry. However, little is known regarding the collection of equine metabolites (metabolome) during a malnourished state and the changes that occur throughout nutritional rehabilitation. In this study, ten emaciated horses underwent a refeeding process, during which blood samples were collected for a blood chemistry panel and metabolomics analysis via ultrahigh performance liquid chromatography–high resolution mass spectrometry (UHPLC-HRMS). Significant differences among blood chemistry analytes and metabolite abundance during the critical care period (CCP; Days 1–10 of rehabilitation) and the recovery period (RP; the remainder of the rehabilitation process) were observed. Potentially toxic compounds, analytes related to liver, kidney, and muscle function, as well as energy-related metabolites were altered during the refeeding process. The combination of blood chemistry and metabolomics analyses on starved equine during rehabilitation provide vital biological insight and evidence that the refeeding process has a significant impact on the equine metabolome.

Performance of predictive models of survival in horses undergoing emergency exploratory laparotomy for colic

Objective

To evaluate previously published predictive survival models in a population of horses undergoing colic surgery in the midwestern United States.

Study design

Retrospective cohort study; single referral hospital.

Animals

A total of 260 horses met the inclusion criteria.

Methods

Medical records of horses undergoing surgical treatment for colic were reviewed. Previously published models were applied to cohort data to predict outcome. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for prediction of short‐term survival were calculated.

Results

Single‐variable and multivariable models performed similarly for prediction of survival, with a mean 79% sensitivity (range: 44%–94%), 48% specificity (range: 22%–83%), 63% PPV (range: 56%–72%), 73% NPV (range: 60%–83%), and 64% accuracy (range: 59%–72%). Blood lactate ≤6 mmol/l and the colic severity score (CSS) were highly sensitive for prediction of survival; however, both had poor specificity.

Conclusion

Single‐variable and multivariable predictive models did not perform as well for prediction of survival in the study cohort compared to original reports, suggesting that population‐specific factors contribute to patient survival.

Clinical significance

Predictive models of survival developed in one population may be less reliable when used to predict outcome in horses undergoing colic surgery from an independent population. Additional model testing and refinement using data from multiple surgical centers could be considered to improve prediction of outcome for horses undergoing laparotomy for treatment of colic.

Blood glucose and subcutaneous continuous glucose monitoring in critically ill horses: A pilot study

This pilot prospective study reports the feasibility, management and cost of the use of a continuous glucose monitoring (CGM) system in critically ill adult horses and foals. We compared the glucose measurements obtained by the CGM device with blood glucose (BG) concentrations. Neonatal foals (0–2 weeks of age) and adult horses (> 1 year old) admitted in the period of March-May 2016 with clinical and laboratory parameters compatible with systemic inflammatory response syndrome (SIRS) were included. Glucose concentration was monitored every 4 hours on blood samples with a point-of-care (POC) glucometer and with a blood gas analyzer. A CGM system was also placed on six adults and four foals but recordings were successfully obtained only in four adults and one foal. Glucose concentrations corresponded fairly well between BG and CGM, however, there appeared to be a lag time for interstitial glucose levels. Fluctuations of glucose in the interstitial fluid did not always follow the same trend as BG. CGM identified peaks and drops that would have been missed with conventional glucose monitoring. The use of CGM system is feasible in ill horses and may provide clinically relevant information on glucose levels, but there are several challenges that need to be resolved for the system to gain more widespread usability.

Evaluation of Blood Glucose and Lactate Concentrations in Mule and Equine Foals

Information about mule physiology is scarce. Glucose and lactate serve as prognostic tools in neonates; thus, real-time evaluations would be beneficial. Our main objective was to measure glucose and lactate concentrations from healthy mule and equine foals from birth to 720 hours. Glucose and lactate concentrations were evaluated with a benchtop Randox Daytona analyzer (LAB) using plasma and with an Accutrend Plus system (ACP) using whole blood. Data were analyzed using PROC MIXED (P < .05), intraclass coefficient correlation and Bland-Altman analysis. Glucose and lactate concentrations from mule and equine foals were different when evaluated with LAB, but there was no difference when evaluated with ACP. Glucose pattern of variation, evaluated with both analyzers for mule and equine foals, had an increase, with subsequent decrease, whereas lactate pattern of variation had initial higher values with subsequent decrease. Intraclass coefficient correlation for glucose was low and moderate for lactate. Results of glucose and lactate with ACP from our experimental neonates were not highly correlated with LAB. However, the ACP had the same pattern of variation for glucose and lactate, thus can still be used clinically for immediate evaluations if the technique is standardized with the specific samples that will be used.

Evaluation of podocin in urine in horses using qualitative and quantitative methods

No sensitive method for diagnosing early kidney dysfunction in horses has been identified so far. Many studies carried out in humans and small animals show that podocin can be useful to diagnose various kidney diseases, mainly affecting the glomeruli. The aim of this study was to perform a qualitative and quantitative analysis of podocin in urine samples obtained from healthy horses, horses with clinical kidney dysfunction and horses at risk of acute kidney injury. The study objectives aimed to assess: (1) whether the selected podocin tryptic peptide for LC-MS-MRM allows for podocin detection in horse; and (2) whether the species-specific ELISA test makes this detection possible as well;, (3) whether the chosen methods are sensitive enough to detect kidney dysfunction and glomerular injury, (4) whether the results of the tests applying both methods correspond with one another, (5) whether the results correlate with the hematological and biochemical data. The signals that may indicate the presence of trypsin fragments of podocin were found in three healthy horses, all the horses diagnosed with kidney dysfunction and half of the animals at risk for acute kidney injury. The concentration of podocin, diagnosed with the ELISA test was as follows: from 0.19 to 1.2 ng/ml in healthy animals, from 0.19 to 20.0 ng/ml in AKI horses, from 0.29 to 5.71 ng/ml in horses at risk for acute kidney injury. The results of both methods corresponded significantly. Podocin may be a potential biomarker of clinical kidney disease in horses and may be used in the detection of glomerular injury. However, its use is limited by the possibility of physiological podocyturia. LC-MS-MRM seems to be a more sensitive method to evaluate the presence of podocin than the ELISA test, whilst selected tryptic peptides of podocin appear to apply to horses. The ELISA test showed greater effectiveness in excluding the disease than in confirming it.

A high glucose concentration during early stages of in vitro equine embryo development alters expression of genes involved in glucose metabolism

BACKGROUND

Equine embryos exhibit an unusual pattern of glucose tolerance in vitro and are currently cultured in hyperglycaemic conditions.

OBJECTIVE

Our main objective was to analyse the effect of different glucose concentrations on in vitro-produced equine embryo development and quality.

STUDY DESIGN

Experiments comparing in vitro and in vivo produced embryos.

METHODS

Oocytes (n = 641) were collected from post-mortem ovaries, matured in vitro and fertilised by intracytoplasmic sperm injection (ICSI). Embryo culture was divided from Day 0 to Day 4 and from Day 4 to Day 9 in three groups: 5-10 (5 and 10 mmol/L glucose respectively; n = 87); 5-17 (5 and 17.5 mmol/L; n = 66); and 10-17 (10 and 17.5 mmol/L; n = 117). A control group of 20 in vivo produced blastocysts was included. Cleavage and blastocyst rates were evaluated and embryos were snap-frozen for analysis of the relative mRNA expression of genes related to mitochondrial function, DNA methylation, apoptosis, glucose transport and metabolism.

RESULTS

No differences were observed in the cleavage or blastocyst rates among in vitro groups. Under high glucose conditions in vitro (10-17 group), BAX/BCL2 was higher, and PFKP, LDHA and COX2 were overexpressed compared to all other groups. The two groups with 5 mmol/L glucose concentration during the first culture stage (5-10 and 5-17) displayed similar patterns which differed to the 10-17 group.

MAIN LIMITATIONS

Conclusions related to embryo quality are based on gene expression patterns. Transfer of in vitro-produced embryos would reveal whether the observed differences improve embryo developmental competence.

CONCLUSIONS

Five mM glucose during the first days of culture seems to be preferable to avoid over-activation of embryonic glycolytic pathways. Further studies are necessary to determine whether this improves embryo developmental competence.

Accuracy of differences in blood and peritoneal glucose to differentiate between septic and non-septic peritonitis in horses

Difference in blood and peritoneal glucose (DBPG) is used in clinical practice to support a diagnosis of septic peritonitis in horses. It is inexpensive, easy and rapid to perform. The aim of this study was to evaluate the accuracy of the DBPG to differentiate between septic and non-septic peritonitis in horses. Blood and peritoneal fluids were harvested from suspected animals. Plasma and peritoneal glucose levels, total nucleated cell count, direct microscopic and microbiological examinations of the peritoneal fluid were evaluated. Using DBPG levels, the animals were classified into two groups: difference ≥ 50 mg/dL (positive test) and difference < 50 mg/dL (negative test). Positive microbiological examination and/or presence of bacteria in direct microscopic examination was used as a gold standard to detect septic peritonitis. The accuracy parameters analysed were: sensitivity, specificity, and positive/negative predictive values, for which the results were respectively: 0.23, 0.91, 0.60 and 0.67. Due to poor accuracy, other cut-off margins and peritoneal glucose concentrations were evaluated. The test was considered most accurate when the DBPG was zero with sensitivity, specificity, and positive/negative predictive values of 0.85, 0.82, 0.73, 0.90 respectively. Peritoneal glucose concentrations alone were not a reliable feature to detect peritonitis. DBPG ≥50 mg/dL, widely used for the diagnosis of septic peritonitis, does not have a good accuracy and the DBPG = 0 has a better accuracy for detecting the disease.

Determination of haematological and biochemical parameters of Calf Saiga antelope (Saiga tatarica) living in the Gansu Endangered Animals Research Center

BACKGROUND

The Saiga antelope (Saiga tatarica) is native to Eurasia and is a member of the family Bovidae. Prior to 1920, the antelope had been extensively hunted for its horns, which were used in traditional Chinese medicine. Since 1920, the Saiga antelope has been protected because of this extensive hunting, which nearly led to its extinction.

OBJECTIVE

The study evaluated haematological and biochemical parameters to provide references for the Calf Saiga antelope (S. tatarica). The study also sought to explore the mechanisms affecting these parameters in both genders of the Calf Saiga antelope.

METHODS

Haematological and biochemical parameters were collected from the Calf Saiga antelope. Haematological and biochemical parameters were analysed by the Coulter counter and Automatic analyser, respectively.

RESULTS

The average concentrations of female triglyceride levels showed significantly higher values than the significant concentrations of male. Female red blood cells and platelets concentrations were statistically significant than the significant concentrations of males. Magnesium female concentrations were also significantly higher than male values. Other parameters showed differences between males and females.

CONCLUSION

The reported results show that haematological and biochemical characteristics varied among Calf Saiga antelope and other animals. The study results suggest that regardless of the factors, breed, the breeding environment, and climatic variables, haematological and biochemical variations can be triggered that can result in a reduction in the heat production needed for maintenance of homeothermy.

Precision and accuracy of a point-of-care glucometer in horses and the effects of sample type

Point-of-care glucometry is used commonly in clinical and research settings; however, accuracy and precision of this method are concerns. The objectives of this study were to determine the accuracy of glucometry in adult horses and the precision of duplicate measurements. Blood samples were collected from 62 horses into one plain syringe, one EDTA tube and three fluoride oxalate (FO) tubes. Immediately after collection, glucose concentrations in whole blood were determined, in duplicate, by glucometry from the syringe (plain whole blood [WB] group), EDTA tube (EDTA group) and one FO tube (FO group). One FO sample was used to measure plasma glucose concentration by a laboratory chemistry analyser (LAB group) ≤1 h after collection. The third FO tube was used to measure plasma glucose concentration by glucometry after 3 h storage (FO3hr group). Adequate precision was present for all groups (coefficient of variation: 0.7-3.5%) except WB (5.5-9.4%). Between groups, correlations were significant (P < 0.05; except for WB-EDTA), varied with group comparison, and tended to be lowest for comparisons involving WB. Mean bias was lowest for WB-LAB and greatest for FO-LAB and FO3hr-LAB; however, the limits of agreement were ≥4.65 mmol/L for WB-LAB and ≤2.75 mmol/L for most other comparisons. For the glucometer used, performance was influenced by sample type: WB was unsuitable, while FO or EDTA samples resulted in adequate precision and accuracy, provided under-estimation of glucose concentrations is accounted for by using method-specific reference ranges. Glucometer performance and optimal sample type(s) should be determined prior to use in horses.

Effect of standard clinical procedures on blood glucose concentration in clinically healthy horses

BACKGROUND

Blood glucose concentrations fluctuate with stress, but little is known on how it is influenced by clinical procedures. The objective was to investigate the effect of clinical procedures on blood glucose concentration in healthy horses.

MATERIALS AND METHODS

Prospective, experimental study. Seven hospital-owned research horses were included in the study. A total of 4 horses were sampled either during a control sedation trial or during 3 different student workshops (prepurchase, oral, and rectal examination-the latter 2 with sedation). Blood samples were taken every 15 minutes and glucose concentration in whole blood was measured immediately with a previously validated handheld glucometer until normalization after the end of the workshops. No food was provided during sampling periods.

KEY FINDINGS

All measured blood glucose concentrations remained within reference interval. A significant increase in blood glucose concentration between baseline and peak was found during sedation (P = 0.005) and the oral workshop (P = 0.031). A decrease was found during prepurchase examination (P = 0.006; before exercising). Peak glucose concentration values between the sedation trial and both the oral (P = 0.065) and rectal workshop (P = 0.709) were not statistically different. Glucose measurements returned to baseline 1 hour after completion of the workshops.

SIGNIFICANCE

No impact of different clinical procedures on the blood glucose concentration over the effects of sedation was found. It is advisable to wait 1 hour after a procedure to measure blood for glucose concentration in horses.

Clinical findings associated with development of postoperative reflux and short-term survival after small intestinal surgery in geriatric and mature nongeriatric horses

OBJECTIVE

To determine risk factors, especially age, associated with postoperative reflux (POR; >2 L of reflux present upon intubation), high-volume POR (≥20 L in 24 hours), and short-term outcome after small intestinal (SI) surgery.

STUDY DESIGN

Retrospective case-control study.

SAMPLE POPULATION

Horses aged ≥16 years (geriatric; range, 16-30; n = 44) and <16 years (mature; range, 2-15; n = 39) with an SI surgical lesion that survived general anesthesia and did not have a second exploratory celiotomy during the same visit.

METHODS

Medical records (2009-2015) were reviewed; perioperative variables were evaluated for associations with outcomes by using multivariable logistic regression.

RESULTS

Postoperative reflux was associated with an increasing packed cell volume at admission (odds ratio [OR], 1.08; 95% CI, 1.00-1.16; P = .042) and presence of nasogastric reflux at admission (OR, 4.61; 95% CI, 1.3-15.69; P = .014). High-volume POR was associated with an increasing glycemia at admission (OR, 1.19; 95% CI, 1.01-1.40; P = .041), presence of nasogastric reflux at admission (OR, 10.05; 95% CI, 2.21-45.74; P = .003), and SI resection (OR, 10.52; 95% CI, 1.81-61.25; P = .009). Increasing surgical time (OR, 2.50; 95% CI, 1.16-5.29; P = .019) and high-volume POR (OR, 6.37; 95% CI, 2.12-19.12; P = .001) were associated with nonsurvival.

CONCLUSION

Age, considered as both a continuous variable and a categorical variable, was not associated with the development of POR, high-volume POR, or nonsurvival.

CLINICAL SIGNIFICANCE

Age does not influence the occurrence of POR and should not negatively impact an owner's decision to pursue surgery in aged horses.

In Vitro Culture of Embryos from Horses

Establishment of optimal methods for equine embryo culture has been slow when compared to some domestic species. In part, this delay was caused by the failure of standard in vitro fertilization techniques in horses. However, the development of intracytoplasmic sperm injection (ICSI) for the assisted fertilization of equine oocytes has resulted in a renewed interest in establishing optimal methods for embryo culture. Currently, ICSI-produced equine embryos are cultured using media designed for other species or other cell cultures and, typically, with the addition of serum. Although systems specifically for horse embryo culture still have not been established, ICSI-produced embryos are developmentally competent and capable of producing live offspring.

Presumed Neuroglycopenia Caused by Severe Hypoglycemia in Horses

BACKGROUND

Neuroglycopenia refers to a shortage of glucose in the brain resulting in neuronal dysfunction and death if left untreated. Presumed neuroglycopenia has not been described in horses.

OBJECTIVE

To report neurological signs in horses with presumed neuroglycopenia as the result of severe hypoglycemia.

ANIMALS

Ninety horses (hours to 28 years of age) diagnosed with hypoglycemia (blood glucose concentration < 75 mg/dL [< 4.2 mmol/L]).

METHODS

Retrospective study. Electronic medical records were searched. Signalment, history, complaint, clinical signs, laboratory findings including CSF analysis, electroencephalogram, clinical or definitive diagnosis, and outcome were recorded. Kruskal-Wallis analysis of variance and logistic regression were used to investigate association between blood glucose concentration and data extracted. Statistical significance was set at P < 0.05.

RESULTS

Thirty-eight and 52 horses had mild (50-74 mg/dL [2.8-4.1 mmol/L]), and severe hypoglycemia (< 50 mg/dL [< 2.8 mmol/L]), respectively. Most common causes of hypoglycemia included liver and gastrointestinal (40%) disease, sepsis (33%), neoplasia (7%), and insulin-induced (4%). Most common neurologic deficits included obtundation (100%), seizures (42%), and disorientation (22%). CSF-glucose was severely low (mean 2.5 mg/dL [0.1 mmol/L], median 0 mg/dL). Paroxysmal discharges in support of seizures were identified in the occipital (visual) and parietal (closest to temporal-auditory) cortical regions upon EEG examination (8/8 horses).

CONCLUSIONS AND CLINICAL IMPORTANCE

Neuroglycopenia is presumed to occur in horses as the result of severe hypoglycemia. Subclinical seizures, and intermittent blindness and deafness of cortical origin can occur. Severe altered state of consciousness and seizures can be observed at a blood glucose cut-off value of < 42 mg/dL (< 2.3 mmol/L).

Insulin dysregulation in horses with systemic inflammatory response syndrome

BACKGROUND

Systemic inflammation is a cause of insulin dysregulation in many species, but the insulin and glucose dynamics in adult horses diagnosed with systemic inflammatory response syndrome (SIRS) are poorly documented.

HYPOTHESIS/OBJECTIVES

In SIRS in horses, insulin and glucose dynamics will be altered and associated with survival.

ANIMALS

Adult horses diagnosed with SIRS admitted to a referral hospital.

METHODS

Prospective study enrolling horses diagnosed with SIRS in which serum insulin and glucose concentrations were measured. Horses were grouped by outcome (survival, hyperinsulinemia, and hyperglycemia) and compared with P < .05 considered significant.

RESULTS

Fifty-eight horses were included in the study and 36 (62%) survived. At admission, 21 horses (36%) were hyperinsulinemic and 44 horses (88%) were hyperglycemic, with survivors having significantly higher serum insulin and a significantly lower serum glucose concentration. Horses diagnosed with hyperinsulinemia at any time during hospitalization were 4 times more likely to survive whereas horses that were hyperglycemic at any time during hospitalization were 5 times less likely to survive. Serum glucose concentration and presence of hyperglycemia both were associated with severity of disease. Insulin/glucose ratio, reflecting insulin secretion, was significantly higher in survivors whereas glucose/insulin ratio, reflecting peripheral tissue insulin resistance, was significantly lower in nonsurvivors. Only in survivors was there a significant correlation between serum insulin and glucose concentrations.

CONCLUSIONS AND CLINICAL IMPORTANCE

Hyperinsulinemia and hyperglycemia are common features of SIRS in horses, but those presenting with relative hypoinsulinemia and corresponding hyperglycemia suggestive of endocrine pancreatic dysfunction have a worse prognosis.

Blood glucose is unlikely to be a prognostic biomarker in acute colitis with systemic inflammatory response syndrome in Thoroughbred racehorses

Although hyperglycemia at admission with colic has been reported to have a poor prognosis, there is no report specifically about acute colitis with systemic inflammatory response syndrome (SIRS) in horses. In this study, we measured blood glucose (Glu), insulin (Ins), and cortisol (Cor) levels in 17 Thoroughbred racehorses diagnosed as having acute colitis with SIRS, and examined the relationship between time-dependent changes in Glu, Ins, and Cor and prognosis. Glu levels were high in 3 horses at admission, but thereafter no horses had persistently high Glu levels. There was no significant difference in Glu, Ins, and Cor levels within 72 hr between surviving and non-surviving horses. In conclusion, the Glu level is unlikely to be a useful prognostic biomarker in acute colitis with SIRS.

Comparison of jugular and transverse facial venous sinus blood analytes in healthy and critically ill adult horses

OBJECTIVE

To compare blood gas, electrolyte, and metabolic analysis results between blood obtained by jugular and transverse facial venous sinus (TFVS) venipuncture in healthy adult horses and sick adult horses presented for emergency evaluation.

DESIGN

Prospective, experimental study, from June 2012 to October 2013.

SETTING

Large animal university teaching hospital.

ANIMALS

Ten healthy adult University-owned horses and 48 client-owned adult horses (≥2 years old) presenting to the large animal hospital emergency service for medical or surgical evaluation of systemic illness.

INTERVENTIONS

Venipunctures (jugular vein [JV] and TFVS) were performed using preheparinized syringes and obtained prior to institution of medical therapy. Samples were analyzed in random order within a 10-minute interval using a point-of-care blood gas analyzer (NOVA Critical Care Xpress) that also reports electrolyte and metabolite results. Comparisons between venipuncture sites were analyzed using the Student's paired t-test for normally distributed data and the Wilcoxon paired test for nonnormally distributed data. Bland-Altman analysis was used to assess agreement between venipuncture sites.

MEASUREMENTS AND MAIN RESULTS

There were no statistically significant differences found between variables for JV and TFVS in healthy horses. In sick horses, JV measurements were greater than TFVS for ionized calcium (P = 0.002) and glucose (P = 0.001), and less than TFVS for hematocrit (P = 0.015). Bland-Altman plots demonstrated small biases but overall agreement between sites.

CONCLUSIONS

The TFVS can be used interchangeably with JV for venous blood gas analysis in healthy horses. In sick horses, identified differences were small and likely not clinically important. The reliability of this point-of-care blood gas analyzer for measurement of hematocrit remains to be determined.

The clinical value of whole blood point-of-care biomarkers in large animal emergency and critical care medicine

OBJECTIVE

To summarize the current medical literature and provide a clinical perspective of whole blood point-of-care (POC) biomarkers in large animal emergency and critical care practice.

DATA SOURCES

Original studies, reviews, and textbook chapters in the human and veterinary medical fields.

SUMMARY

POC biomarkers are tests used to monitor normal or disease processes at or near the patient. In both human and veterinary medicine these tools are playing an increasingly important role in the management of critical diseases. The most important whole blood POC biomarkers available for veterinary practitioners include l-lactate, cardiac troponin I, serum amyloid A, triglyceride, creatinine, and glucose, although many other tests are available or on the horizon.

CONCLUSION

Whole blood POC biomarkers enable clinicians to provide improved management of critical diseases in large animals. These tools are especially useful for establishing a diagnosis, guiding therapy, and estimating disease risk and prognosis.

Cardiac arrhythmias and electrolyte disturbances in colic horses

BACKGROUND

Despite increased focus on cardiac arrhythmias in horses, the nature and prevalence is still poorly described. Case reports suggest that arrhythmias occurring secondary to systemic disease are seen more commonly in the clinic than arrhythmias caused by cardiac disease. The aim of this study was to investigate the prevalence of arrhythmias in colic horses referred for hospital treatment. Associations between electrolyte disturbances and arrhythmias were also investigated.

RESULTS

Heart rate was 37.4 ± 3.7 bpm in the control group, and 51.6 ± 11.8 bpm, in the colic group, which was significantly different (P < 0.0001). AV blocks and SVPCs were found in both groups, however only colic horses showed VPCs. No significant difference between the two groups was found for AV blocks, SVPCs, and VPCs (P = 0.08 - 0.76). The mean levels of potassium, sodium, ionized calcium, and chloride were significantly lower in the colic group compared to the control group at admission. Mean levels of glucose and L-lactate were significantly elevated in the colic group (P < 0.05).

CONCLUSIONS

This study describes prevalence of cardiac arrhythmias and electrolytes concentrations in colic horses compared to healthy controls. Although we only observed VPCs in the colic horses, no significant differences between colic horses and controls were found. Despite the colic horses having electrolyte changes at admission no correlation was found between the electrolyte disturbances and cardiac arrhythmias. Although no clear conclusions can be drawn from the present study, the results indicate that relatively mild colic per se is not pro-arrhythmogenic, whereas severe colic probably are more likely to result in ventricular arrhythmia.

Evaluation of the colic in horses: decision for referral

This article presents an overview of key factors that should alert the practitioner toward referral of a colic patient to a facility capable of surgical exploration or intensive medical management. Discussion includes a review of important aspects of colic history, signalment, physical examination findings, and diagnostic test results that indicate that a more serious medical or surgical condition exists, and advanced therapy is necessary.

Evaluation of a continuous glucose monitoring system compared with an in-house standard laboratory assay and a handheld point-of-care glucometer in critically ill neonatal foals

OBJECTIVE

To evaluate the applicability and accuracy of a continuous glucose monitoring system (CGMS) in critically ill foals by comparing the performance of the CGMS, a point-of-care (POC) glucometer, and an in-house standard laboratory assay (SLA).

DESIGN

Prospective study.

SETTING

University teaching hospital.

ANIMALS

Seven critically ill neonatal foals requiring intensive care.

INTERVENTIONS

Foals were instrumented with a CGMS that measured interstitial glucose concentration every 5 minutes for the duration of 15-79 hours. Capillary and venous blood samples were taken every 4-6 hours for POC and SLA measurements, respectively.

MEASUREMENTS AND MAIN RESULTS

Bland-Altman analysis showed a mean bias (95% limits of agreement) of -0.1 (-3.9 to 3.5) mmol/L for comparison of CGMS versus SLA, 0.06 (-3.9 to 4.0) mmol/L for comparison of CGMS versus POC glucometer, and -0.16 (-1.8 to 1.5) mmol/L for comparison of POC glucometer versus SLA. Percent agreement and weighted kappa for classification in hypoglycemia, normoglycemia, and hyperglycemia were 68.4% and 0.296 for CGMS versus SLA, 72.4% and 0.442 for CGMS versus POC glucometer, and 80.7% and 0.568 for POC glucometer versus SLA.

CONCLUSIONS

The CGMS may be helpful for monitoring a trend in interstitial glucose concentration in critically ill neonatal foals. However, considering the wide limits of agreement between methods, the CGMS should only be used as an adjunctive device to other, more accurate and readily available methods that are able to detect acute changes in glucose concentration. Its use is further limited by the relatively high costs of the sensors, the mandatory 2-hour initialization period, and the difficulties of keeping the transducer in place in an active foal. The POC glucometer used in this study is easy to use and proved to be sufficiently accurate for repeated, stall-sided glucose monitoring in neonatal foals.

Anesthesia for the horse with colic

This article discusses anesthesia for horses with colic from acute gastrointestinal disease. Emphasis is placed on new developments in pre-, intra-, and immediate postoperative management over the last decade, including early goal-directed therapy (EGDT) in the resuscitation of septic patients, the controversy over the optimal fluid type to administer, and the management of complications, such as cardiovascular depression, hypoventilation and hypoxemia, and decreased colloid oncotic pressure (COP). An update on analgesia is also provided; older drugs such as ketamine and lidocaine are increasingly being recognized both for their analgesic properties and other potentially beneficial effects in endotoxemic horses.

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]deltaT) 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]deltaT 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]deltaT can be a useful prognostic indicator in horses.

Evaluation of a veterinary glucometer for use in horses

BACKGROUND

Glucose assessment and regulation are important factors in the treatment of hospitalized horses and foals.

HYPOTHESIS/OBJECTIVES

The purpose of this study was to compare glucose measurement by a veterinary glucometer, adjusted by code for use in horses and foals, to a reference chemistry analyzer. It was hypothesized that the veterinary glucometer and reference analyzer would yield similar results and that interpretation of glucose values obtained from a veterinary glucometer would result in clinically appropriate decisions.

ANIMALS

Fifty blood samples from adult horses and 50 blood samples from neonatal foals admitted to the Colorado State University Veterinary Hospital or Equine Reproduction Laboratory for evaluation.

METHODS

Glucose concentrations from fresh whole blood samples were evaluated in duplicate with a veterinary glucometer and these values were compared with those obtained with a reference plasma chemistry analyzer. The accuracy of glucometer measurement was evaluated with a Clarke error grid.

RESULTS

The veterinary glucometer accurately measured whole blood glucose concentrations in both horses and foals when compared with a reference plasma chemistry analyzer. Nearly 97% of the glucometer values obtained in this study would have resulted in appropriate clinical decisions based on the Clarke error grid analysis.

CONCLUSIONS AND CLINICAL IMPORTANCE

The veterinary glucometer evaluated has potential utility for point-of-care whole blood glucose evaluation in both horses and foals.

Prognosticating equine colic

Prognosticating survival in horses with colic is challenging because of the number of diseases and pathophysiologic processes that can cause the behavior. Although the treatment of horses with colic has improved dramatically over the years, case fatality can still be high because of the delay in recognizing the problem, the time delay inherent in receiving veterinary care, and the lack of effective treatment for the more severe diseases. Intensive case management and surgery for these horses may be expensive and emotionally draining for owners; therefore, providing an accurate prognosis is key to decisions needed for case management. This article is dedicated to recent advances in applying a prognosis for survival in horses at higher risk for a fatal outcome.

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.

Comparison of the Accu-Chek Aviva point-of-care glucometer with blood gas and laboratory methods of analysis of glucose measurement in equine emergency patients

BACKGROUND

More information is needed regarding accuracy of commonly used methods of glucose measurement in the critically ill horse.

HYPOTHESIS

Glucometry will have good agreement with a laboratory standard. Glucometry with plasma will have better agreement than when performed with whole blood.

ANIMALS

Fifty sequentially admitted equine emergency patients, aged >1year.

METHODS

Venous blood was collected at admission and immediately analyzed by point-of-care glucometry on both whole blood (POC/WB) and plasma (POC/PL), a multielectrode blood gas analyzer with whole blood (BLG), and a standard laboratory method with plasma (CHEM). Paired data were compared using Lin's concordance correlation, Pearson's correlation, and robust regression. Bias and limits of agreement were tested by the Bland-Altman technique. Bivariate regression analysis was used to explore confounding factors.

RESULTS

Concordance was significant for all comparisons, and was strongest for CHEM-POC/PL (0.977) and weakest for POC/WB-POC/PL (0.668). Pearson's correlation was excellent for all comparisons except those with POC/WB. All comparisons had excellent robust regression coefficients except those with POC/WB.

CONCLUSIONS AND CLINICAL IMPORTANCE

POC glucometry with plasma had excellent agreement with a laboratory standard, as did blood gas analysis. POC glucometry with whole blood correlated poorly with a laboratory standard. These differences may be clinically important, and could affect decisions based on glucose concentrations.