Sequential plasma lactate concentrations as prognostic indicators in adult equine emergencies

Evaluation of peritoneal l-lactate concentration in horses in the early post-partum period

BACKGROUND

Peritoneal fluid lactate concentration is an important diagnostic tool in horses with abdominal pain. Information on peritoneal lactate concentrations is lacking following parturition in the mare.

OBJECTIVES

To compare blood and peritoneal lactate concentrations in a population of mares within 36 h post-partum, report a normal reference range and identify any impact of retained foetal membranes (RFMs).

METHODS

This is a retrospective study evaluating healthy mares from which blood and peritoneal samples had been obtained within 36 h of parturition. Exclusion criteria included signs of abdominal pain within this period. Data was interrogated for normality using a Shapiro-Wilk test. Wilcoxon signed-rank test and Bland-Altman analysis were used to compare blood and peritoneal lactate concentrations. Linear regression was used to compare age and breed data with peritoneal lactate concentrations. Significance was defined as p < 0.05.

RESULTS

Forty mares met the inclusion criteria. Mean age was 12.6 ± 4.1 years, and most mares were multiparous (65%). Peritoneal lactate ((1.2 (IQR = 0.9-1.6) mmol/L) was increased compared to blood lactate concentration (0.7 (IQR = 0-1.1)mmol/L; p < 0.001). Plasma total protein (TP) concentrations were 68 (IQR = 64-74) g/L and peritoneal protein concentrations 8 (IQR = 4-9.7) g/L. Six mares developed RFM. The median fold-increase in peritoneal lactate concentration compared to blood lactate concentration was 0.9 (IQR: 0.01-1.7; range: 0-2.5). The reference range for peritoneal fluid lactate concentration was 0-2.5 mmol/L.

CONCLUSION

Peritoneal lactate concentrations in healthy post-partum mares remained within the normal reference range and were not influenced by RFM or parturition. Increased peritoneal lactate in this group warrants further investigation.

Comparison of plasma l-lactate between jugular and cephalic veins in healthy and systemically ill horses using a point-of-care device

OBJECTIVE

To compare plasma l-lactate (LAC) values between samples collected from jugular and cephalic venipuncture in healthy horses and systemically ill horses.

DESIGN

Prospective, experimental study.

SETTING

Large animal university teaching hospital.

ANIMALS

Thirty healthy adult university-owned horses and 43 client-owned horses presenting to the large animal hospital for elective surgical procedures or for emergent medical evaluation of systemic illness.

INTERVENTIONS

Blood samples were collected from the jugular vein (JV) and cephalic vein (CV) and placed in EDTA blood tubes prior to any medical therapy. LAC values were obtained with a handheld lactate meter at the time of blood collection.

MEASUREMENTS AND MAIN RESULTS

LAC was higher in CV samples than JV samples in healthy horses (P < 0.001); however, all values were within the normal reference range. Similarly, LAC was higher in CV samples than JV samples in systemically ill horses (P < 0.001), but the median JV value was within normal reference range (1.9 mmol/L [17.1 mg/dL]), while the median CV value was outside the normal reference range (2.9 mmol/L [26.1 mg/dL]).

CONCLUSIONS

The CV is an alternative venipuncture site for assessing plasma LAC if the JV is not accessible or to preserve the JV for subsequent catheterization. However, in ill horses, the CV value may be outside the reference range when the corresponding JV value would have been within the reference range.

Evaluation of Blood Lactate, Heart Rate, Blood Pressure, and Shock Index, and Their Association with Prognosis in Calves

Diseases in young calves received as emergencies are often associated with hypovolemic and/or septic shocks. The objectives of our study were to (1) assess the correlation between clinical hemodynamic parameters and blood L-lactates (LAC), systolic blood pressure (SBP), and the shock index (SI) recorded upon arrival; and (2) to evaluate how these parameters were related to short-term outcomes in calves under 4 months of age presented as emergencies. We conducted a single-observer prospective observational study on calves aged from 1 day to 4 months, presented to the Veterinary Clinic for Ruminants of Liège from December 2020 to May 2022. Forty-five calves were included in the study. The statistical analysis revealed a significant correlation between LAC and heart rate (r = 0.570; p < 0.05) and LAC and SI (r = 0.373; p < 0.05). A high LAC value at admission was significantly associated with a negative outcome (death) (p < 0.05). In calves suffering from obstructive digestive diseases, the SI was related to the outcome and the analysis indicated a cut-off value of 1.13 (Se = 0.77, Spe = 1). In conclusion, in our study, the initial blood L-lactate value was correlated with heart rate, the shock index, and the clinical shock score, and admission hyperlactatemia was associated with a poor prognosis in calves under 4 months of age. In this cohort, the shock index in calves suffering from digestive diseases was linked with mortality.

Retrospective evaluation of factors associated with emergency frequency and survival in equids presenting for emergency care (2019-2020): 3071 cases

OBJECTIVE

To determine factors associated with frequency and outcome of equid emergencies in private practice.

DESIGN

Retrospective study from February 2019 to January 2020.

SETTING

Private practice large animal hospital.

ANIMALS

A total of 3071 equids of various breeds and ages presenting for emergency care.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Variables included for analysis of daily emergency frequency included day of the week, month, and daily climate data. A Poisson regression model found the maximum temperature (P = 0.05), average barometric pressure (P = 0.005), and decreases in barometric pressure (P = 0.05) were associated with an increasing daily number of emergencies. Overall survival for all emergencies was 89% (2748/3071). Variables included for analysis of nonsurvival for emergencies included signalment, body system, clinical examination findings, laboratory data, and experience of the veterinarian. A logistic regression model for primary emergencies (nonreferral) found that increasing age, increasing heart rate, and decreased gastrointestinal sounds were associated with an increase in nonsurvival. Body system and experience of the veterinarian affected nonsurvival. A logistic regression model for all emergencies (primary and referral) found that absent gastrointestinal sounds and an increasing PCV were associated with increased nonsurvival.

CONCLUSIONS

The number of daily emergencies in this practice was affected by the month of the year and day of the week. Additionally, hotter days, increased barometric pressure, or drops in barometric pressure are likely to be associated with a higher emergency caseload. Nonsurvival of primary equid emergencies in private practice increases with age, higher heart rates, and decreased gastrointestinal sounds.

Epidemiology of Colic: Current Knowledge and Future Directions

Epidemiologic studies are essential for the generation of evidence-based, preventive health care strategies. This includes ways to minimize colic risk and assist informed decision making concerning diagnosis, treatment, and likely outcomes. It is important to consider that colic is not a simple "disease" but is a syndrome of abdominal pain that encompasses multiple different disease processes, and which is multifactorial in nature. This review focuses on prevention and diagnosis of colic, including specific forms of colic, communications with owners/carers concerning colic risk and management, and areas of future research.

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.

Serum amyloid A does not predict non-survival in hospitalised adult horses with acute colitis

BACKGROUND

Predicting non-survival in horses with acute colitis improves early decision making. Therefore, this study aimed to determine the prognostic value of serum amyloid A (SAA) and other clinicopathological and clinical variables in adult horses with acute colitis.

METHODS

Clinical variables, SAA and other blood biomarkers, including plasma L-lactate (lactate), were assessed in 176 horses with acute colitis. A multivariate model for the prediction of non-survival was constructed. Icelandic horses were analysed separately.

RESULTS

Admission SAA was similar in survivors (median 548 mg/L; range 0-5453 mg/L) and non-survivors (396 mg/L; 0-5294) (p = 0.43). A model for non-survival included year of admission, lactate, heart rate, age and colic duration of more than 24 hours. Icelandic horses had a relative risk of 2.9 (95% confidence interval = 2.2-3.8) for acute colitis compared to other breeds. Lactate in Icelandic horses was higher than that in other breeds in both survivors (4.0 mmol/L, range 1.0-12.7 vs. 2.0, 0.7-12.5) and non-survivors (10.0, 1.5-26 vs. 5.4, 0.8-22) (p < 0.001).

LIMITATIONS

The prognostic value of repeated measurements of SAA could not be assessed in this study, as 71% of the non-surviving horses died within a day of admission.

CONCLUSION

Admission SAA did not predict non-survival. Breed needs consideration when lactate is evaluated as a predictor for non-survival in horses with colitis.

Evaluation of Eosinopenia as a SIRS Biomarker in Critically Ill Horses

Systemic inflammatory response syndrome (SIRS) is a very common finding in critically ill patients. To accurately identify patients with SIRS and those who need intensive care, several markers have been evaluated, including cortisol, WBC or lactate. It is widely known that a stress leukogram includes eosinopenia as one of its main markers (neutrophilia, eosinopenia, lymphopenia and mild monocytes). It is known that cortisol concentration in plasma is the main stress biomarker and is strongly correlated with the severity of disease in horses. However, it is not possible to measure this parameter routinely in clinical conditions. Hence, in this study it was hypothesized that the eosinophil count could be a reliable parameter to identify critically ill horses. Horses included in this study were divided into three groups: Group A (sick horses received at the Emergency Unit which did not fulfil the criteria for SIRS), Group B (horses that meet two or more criteria for inclusion in the definition of SIRS) and a control group of healthy horses. In this study, horses with SIRS showed lower eosinophil counts than healthy horses. Moreover, non-surviving horses exhibited lower eosinophil counts than survivors. Eosinopenia could be used to identify horses with SIRS and can be useful as a prognostic marker.

Admission lactate concentration has predictive value for death or severe complications within 30 days after admission in cattle with long-bone fractures

OBJECTIVE

To determine the prognostic value of lactate concentration measurements at admission in cattle with long-bone fractures.

ANIMALS

43 cattle with long-bone fractures between July 2016 and Dec 2018.

PROCEDURES

In this prospective cohort study, lactate concentration was measured in systemic venous blood and locally in capillary blood sampled from the fractured and contralateral limbs of cattle and assessed for outcome prediction. The cutoff value was determined by maximizing the Youden index from receiver-operating characteristic curves. Multivariable logistic regression was employed to verify whether higher lactate concentrations compared with the cutoff value were an independent risk factor for poor outcomes at 30 days or 3 years after admission.

RESULTS

Poor outcome was associated with higher capillary lactate concentration in the fractured limb (P < .001) and greater difference with systemic blood (P = .005). A cutoff value of lactate difference ≥ 2.4 mmol/L (sensitivity = 0.80; specificity = 0.965) between capillary lactate in the fractured limb and systemic blood was the best predictor of death ≤ 30 days after admission (P < .001). Multivariable analysis revealed that this cutoff value was an independent risk factor for 30-day and 3-year outcomes (P < .001).

CLINICAL RELEVANCE

Admission blood lactate concentration difference ≥ 2.4 mmol/L between the fractured limb and systemic blood was a robust and independent predictor of outcome for cattle of the present report. Lactate metabolism is locally impaired in fractured limbs of nonsurviving or at higher complication risk cattle, which may help identify patients at high risk for poor outcomes.

Glucose and Lactate Reference Intervals for White Sturgeon and Evaluation of Two Point-of-Care Devices in Sturgeon Infected with Veronaea botryosa

White Sturgeon Acipenser transmontanus are cultured for human consumption as well as for conservation purposes. In this study, two commercially available portable devices for measuring glucose and lactate were compared to a benchtop analyzer and blood reference intervals were generated using heparin plasma collected from 43 healthy White Sturgeon yearlings. The generated normal ranges were used to compare plasma values collected from Veronaea botryosa-infected White Sturgeon at 10, 20, and 30 d postchallenge (dpc). In the 43 healthy yearlings, significantly different glucose and lactate values were obtained when comparing the portable devices to the benchtop analyzer. In the portable devices, blood glucose showed a consistent bias of 12.3 mg/dL and blood lactate showed a proportional bias. The detected blood glucose values in infected sturgeon were significantly different from those in noninfected controls when using the benchtop analyzer at 20 and 30 dpc and when using the portable device at 20 dpc. However, blood glucose in infected individuals and controls was within the reference interval on either device. No significant difference was noted for lactate measurements in infected sturgeon. The results of this study indicate that portable devices for blood glucose and blood lactate evaluation in White Sturgeon may be useful in a setting where relative values are an acceptable approximation of absolute values.

Interpreting abdominal fluid in colic horses: Understanding and applying peritoneal fluid evidence

BACKGROUND

Interpreting changes in peritoneal fluid helps clinicians manage colic and other diseases in horses. During abdominal problems in the horse, abdominal fluid characteristics such as color, turbidity, total nucleated and red blood cell counts, cytology, total protein, and l-lactate change in predictable ways, helping the clinician characterize the disease.

DESCRIPTION

Normal abdominal fluid in horses is odorless, clear to light yellow in color, and transparent. Peritoneal fluid becomes more turbid with increasing levels of protein, number of WBCs or RBCs, or with gross contamination following intestinal rupture. The color of abdominal fluid will also change with the type and quantity of cells or other elements present. The transformation of peritoneal fluid color from golden to orange to red represents increasing levels of RBCs, common with strangulating intestinal lesions. Serosanguinous defines fluid that is both turbid and orange to bloody because of increased total protein, WBCs, and RBCs, and is considered classic for diseases characterized by intestinal ischemia. Peritoneal fluid may also be red or blood-colored because of a hemoperitoneum, or secondary to blood contamination during sample collection. l-Lactate measurement in the abdominal fluid has proven invaluable for the identification of strangulating intestinal injury. Cytology acts as an important supplement to cell counts in peritoneal fluid, and the normal ratio of non-degenerate neutrophils:mononuclear cells of 2:1 changes during various gastrointestinal diseases. Culture of peritoneal fluid samples should be performed when septic peritonitis is suspected.

SUMMARY

Abdominal fluid is a sensitive indicator of intestinal injury and a useful tool to direct treatment. Peritoneal fluid evaluation includes gross visual and olfactory examination, nucleated cell count, total protein, RBC count, lactate levels, cytology, and culture. The changes noted in such variables are related to the type and duration of the abdominal problem.

KEY POINTS

 Abdominal fluid interpretation has become central to the triage and management of challenging equine colic patients.  The transformation of peritoneal fluid color from golden to orange to red represents increasing levels of RBCs, common with strangulating intestinal lesions.  Contamination with RBCs at various concentrations may be secondary to vascular (eg, abdominal wall or mesenteric vessels) or splenic trauma during abdominal fluid collection; however, this must be distinguished from orange to red fluid associated with intestinal strangulating obstruction or hemoabdomen  Peritoneal fluid analysis reveals abdominal pathology by recognizing specific changes that occur with disease processes affecting the tissues and organs within this cavity.  Abdominal fluid examination should be used as a tool to direct treatment rather than the definitive test for diagnosis of the acute abdomen  Septic peritonitis in horses most commonly originates secondary to intestinal compromise or accidents (vascular damage, perforation, or surgical manipulation), leading to bacterial translocation into the abdomen.

Prospective evaluation of plasma lactate parameters for prognosticating dogs with shock

OBJECTIVE

To determine whether admission venous plasma lactate concentration, serially calculated lactate variables, or the Acute Patient Physiologic and Laboratory Evaluation (APPLE_fast ) score could discriminate hospital survivors from non-survivors in dogs presenting to the emergency department with clinical signs of shock.

DESIGN

Prospective case series performed over a 24-month period.

SETTING

Large urban private teaching hospital.

ANIMALS

Seventy-one dogs admitted to the ICU with initial peripheral venous plasma lactate concentration > 2.5 mmol/L and clinical and hemodynamic parameters consistent with shock.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Heart rate, systolic blood pressure, temperature, initial venous plasma lactate, and APPLE_fast score were recorded at admission. Lactate concentrations were serially recorded at predefined time points and used to calculate lactate variables, including lactime (time lactate > 2.5 mmol/L), lactate clearance ([lactate_initial - lactate_delayed ]/ lactate_initial × 100), and LAC_AREA (area under the lactate concentration versus time curve). Primary outcome was survival to discharge. Overall survival rate was 61%. Admission plasma lactate did not differ between groups (P = 0.28). Lactime was shorter in survivors vs non-survivors (P = 0.03). Lactate clearance at hours (h) 1, 4, 10, and 16 was greater in survivors vs non-survivors (P < 0.05). Final plasma lactate clearance differed between groups (P < 0.05). LAC_AREA at time intervals 1 to 4 hours, 4 to 10 hours, 10 to 16 hours, and 16 to 24 hours was larger in non-survivors vs survivors (P < 0.05). Total LAC_AREA did not differ between groups (P = 0.51). Admission APPLE_fast was not different between survivors and non-survivors (P = 0.16).

CONCLUSIONS

While neither single APPLE_fast nor admission plasma lactate concentration could discriminate between hospital survivors and non-survivors, measures of lactate clearance can prognosticate survival in dogs with shock.

Fluid Resuscitation for Refractory Hypotension

Hypotension is a common occurrence, especially in anesthetized patients and in critical patients suffering from hypovolemia due to shock and sepsis. Hypotension can also occur in normovolemic animals, anesthetized or conscious, under conditions of vasodilation or decreased cardiac function. The main consequence of hypotension is decreased organ perfusion and tissue injury/dysfunction. In the human literature there is no consensus on what is the threshold value for hypotension, and ranges from < 80 to < 100 mmHg for systolic blood pressure and from < 50 to < 70 mmHg for mean arterial blood pressure have been referenced for intraoperative hypotension. In veterinary medicine, similar values are referenced, despite marked differences in normal arterial blood pressure between species and with respect to humans. Therapeutic intervention involves fluid therapy to normalize volemia and use of sympathomimetics to enhance cardiac function and regulate peripheral vascular resistance. Despite these therapeutic measures, there is a subset of patients that are seemingly refractory and exhibit persistent hypotension. This review covers the physiological aspects that govern arterial blood pressure control and blood flow to tissues/organs, the pathophysiological mechanisms involved in hypotension and refractory hypotension, and therapeutic considerations and expectations that include proper interpretation of cardiovascular parameters, fluid recommendations and therapy rates, use of sympathomimetics and vasopressors, and newer approaches derived from the human literature.

Variations in haematological and biochemical parameters in healthy ponies

Background

Breed specific reference ranges for selected blood parameters are recommended for proper interpretation of blood tests, but there are only few reports dealing with ponies. The purpose of this study was to investigate if blood parameters differ among ponies’ classes and to check if general normal values for equine species are applicable to ponies.

Results

All, except total protein concentration, biochemical parameter significantly (p < 0.05) differed among ponies’ classes. The most pronounced difference was noted in blood lactate concentrations, higher (p < 0.001) in the smallest ponies (class A). In all groups of ponies muscle enzymes (aspartate aminotransferase and creatine kinase) and urea were high when compared to normal values for equine species, but triglycerides and creatinine were low. Blood lactate concentration was high in comparison with normal values for horses only in class A ponies’.

Conclusions

In healthy ponies, blood lactate concentration significantly differs between height classes. Normal values for equine species should not be directly applied to interpret the lactate, triglycerides, aspartate aminotransferase and creatine kinase values in ponies.

Modeling Challenge Data to Quantify Endogenous Lactate Production

With the intention of isolating the susceptibility of modeling methodology to influence our investigation of the infusion data, we used three kinetic approaches to our models: a simple approach, a unit approach, and a novel approach. The simple approach used exclusively built-in modeling features of the software in terms of units of the infusion dilution (mmol/L), as well as in terms of the precision of switching the infusion on and off. The unit approach used the same switching mechanism as the simple approach, but the units were modeled in those of the infusion (e.g., mmol/kg). Thirdly with the novel approach, we used an automated approach to controlling the infusion, in the sense that as the modeling mechanism sensed the slowdown of the infusion, it was gradually turned off. The units of the analysis for the novel approach were exactly the same as those deployed in the unit approach. Our objective here was to see if common pharmacokinetic parameters were seriously impacted by the particular modeling method.

Prognostic utility of pre- and postoperative plasma l-lactate measurements in hospitalized cows with acute abdominal emergencies

The aim of the present analyses was to compare the prognostic value of pre- and postoperative l-lactate measurements in hospitalized cows requiring surgical intervention for an acute abdominal emergency, such as gastrointestinal ileus or peritonitis. For this purpose, we analyzed data from retro- and prospective case series, consisting of 754 and 98 cows, respectively. Plasma l-lactate concentrations (L-LAC) were determined upon admission to the hospital (both study populations), immediately before initiation of surgical intervention (prospective study population), and 6, 12, 24, 48, and 72 h later (prospective study population). The outcome of cows was evaluated until hospital discharge (both study populations) and 3 mo after discharge by a phone call to the farmer (prospective study population). A negative outcome was defined as death or euthanasia during hospitalization, or if discharged animals had an unsatisfied owner or were culled for medical reasons that were directly related to the initial abdominal emergency. For the retrospective study population, the overall survival rate until hospital discharge was 66%. Cows with a negative outcome (median: 6.81 mmol/L) had significantly higher L-LAC than cows with a positive outcome (3.66 mmol/L) of therapy. At the individual diagnosis level, L-LAC was associated with mortality in cows with a diagnosis of abomasal volvulus, local peritonitis, hemorrhagic bowel syndrome, and jejunal volvulus. Considering the whole study population, the area under the receiver operating characteristic curve was 0.66. For the prospective study population, the proportion of cows with a positive outcome was 65% until hospital discharge and 61% after the 3-mo observation period. At all sampling times, before and during the first 12 h after surgical intervention, cows with a negative outcome had significantly higher L-LAC than cows with a positive outcome. The largest area under the receiver operating characteristic curve for L-LAC was observed at 6 h (0.89). A cut-point of 1.77 mmol/L was identified, which had a sensitivity and specificity for predicting a negative outcome until hospital discharge of 88.9 and 73.4%, respectively. The present analyses confirmed previous findings in calves and show that persistent hyper-l-lactatemia during the early postoperative period is a more reliable indicator for a negative outcome than hyper-l-lactatemia before initiation of surgical intervention.

Blood L-Lactate Concentration as an Indicator of Outcome in Roe Deer (Capreolus capreolus) Admitted to a Wildlife Rescue Center

Simple Summary

Roe deer are among the most frequent wild animals admitted to rescue centers in Italy. Reasons for admission include trauma, predation, starvation, and imprinting, with the final aim of hospitalization being full recovery and release into the wild for all cases. An accurate triage procedure is vital for predicting the outcome, to avoid unnecessary time spent in captivity, and an excessive allocation of time and resources on animals with a minimal chance of recovery. Since lactacidosis is often associated with death in hospitalized animals, and has been associated with poor prognosis in humans and domestic animals, we proposed an evaluation of blood L-lactate using a rapid whole blood test in order to predict the outcome of hospitalized roe deer. A cut-off of 10.2 mmol/L was identified as the best, in order distinguish animals with minimal chance of surviving and release. For these animals, humane euthanasia should be considered as an option.

Abstract

Roe deer (Capreolus capreolus) are among the most frequent patients of rescue centers in Italy. Three outcomes are possible: natural death, euthanasia, or treatment and release. The aim of the present study is to propose blood L-lactate concentration as a possible prognostic biomarker that may assist veterinarians in the decision-making process. Sixty-three roe deer, admitted to one rescue center in the period between July 2018 and July 2019, were sampled and divided into 4 groups according to their outcome: (1) spontaneous death (17 cases), (2) humanely euthanized (13 cases), (3) fully recovered and released (13 cases), and (4) euthanized being unsuitable for release (20 cases). In addition, blood samples from 14 hunted roe deer were analyzed as controls. Whole blood lactate concentrations were measured with a point of care lactate meter. Differences among groups were close to statistical significance (p = 0.51). A cut-off value of 10.2 mmol/L was identified: all the animals with higher values died or were humanely euthanized. The results suggest that roe deer with lactatemia higher than 10.2 mmol/L at admission, have a reduced prognosis for survival during the rehabilitation period, regardless of the reason for hospitalization and the injuries reported. Therefore, humane euthanasia should be considered for these animals.

Usefulness of a Point-of-Care Analyzer to Measure Cardiac Troponin I and D-Dimer Concentrations in Critically Ill Horses With Gastrointestinal Diseases

Point-of-care (POC) systems for the joint measurement of Troponin and D-dimers have not been studied in horses. The aim of this study was to perform the validation of a POC system (AQT90 FLEX) for the measurement of cardiac troponin I (cTnI) and D-dimers in the serum of horses with gastrointestinal diseases. The main objective was to evaluate whether or not this system can distinguish healthy animals from diseased animals. A sample of 33 horses was included in the study: control group (n = 10) and horses with gastrointestinal disorders (n = 21), which were classified according to their outcome in survivors (subgroup A = 9) and nonsurvivors (subgroup B = 12). Considering the diagnosis of the process, ill horses were classified into three groups: inflammatory (I = 7), obstructive (O = 9), and strangulating diseases (S = 5). The clinical usefulness of AQT90 FLEX was validated by the study of linearity, coefficient of variation, and detection limits. Later, concentrations of D-dimers and cTnI were measured. A significant increase in both parameters was detected in ill animals (cTnI: control: 0.014 ± 0.01 μg/mL, survivors: 0.27 ± 0.37 μg/mL, nonsurvivors: 0.60 ± 1.21 μg/mL; D-dimers: control: 104.90 ± 30.82 ng/mL, survivors: 1,217.22 ± 1,213.28 ng/mL, nonsurvivors: 1,613.67 ± 1,426.75 ng/mL), although there were no statistically significant differences in concentrations according to diagnosis and outcome. In conclusion, AQT90 FLEX POC analyzer can be used in horses with gastrointestinal diseases to measure cTnI and D-dimer concentrations. It is a quick, practical, and minimally invasive tool that helps in determining the severity of illness.

Prognostic value of colonic and peripheral venous lactate measurements in horses with large colon volvulus

OBJECTIVE

To determine the prognostic value of (1) colonic venous lactate or peripheral lactate values obtained before and after manual correction of a large colon volvulus and (2) a combination of variables including pelvic flexure biopsy.

STUDY DESIGN

Prospective clinical study.

ANIMALS

Forty adult horses in which large colon volvulus was diagnosed intraoperatively.

METHODS

Colonic venous, peripheral venous, and arterial blood samples were collected to measure lactate values before and after manual correction. Mucosal biopsy samples were obtained in cases that underwent enterotomy or colonic resection and anastomosis. Interstitium to crypt (I:C) ratio and hemorrhage scores were measured. Optimal cutoff values were determined by receiver operator curve analysis, and associations between variables and short-term outcome were determined by univariable regression. Short-term survival was defined as horses being discharged from the hospital. P ≤ .05 was considered significant.

RESULTS

No association was found between colonic venous lactate values before (P = .011) or after (P = .201) manual correction of large colon volvulus and determination of short-term outcome. Peripheral venous lactate at admission ≥3.2 mmol/L and after manual correction ≥5 mmol/L, arterial lactate postmanual correction ≥3.53 mmol/L, and histomorphometric measurements of mucosal hemorrhage ≥3 and I:C ratio > 1 were associated with poor short-term outcome.

CONCLUSION

Peripheral lactate values, histomorphometric measures of I:C ratio, and hemorrhage score provided prognostic information that could help guide recommendations made to owners.

CLINICAL SIGNIFICANCE

Peripheral lactate values after manual correction provide important intraoperative diagnostic information to assist in predicting case outcome in the operative and immediately postoperative period.

Prognostic relevance of pre- and postoperative plasma l-lactate measurements in calves with acute abdominal emergencies

In both human and veterinary medicine, l-lactate is a well-established prognostic biomarker of disease severity and mortality and has also attracted increasing attention in bovine medicine due to the availability and validation of cheap and portable l-lactate analyzers. The aim of the present study was to evaluate the prognostic accuracy of plasma L-lactate measurements in calves with acute abdominal emergencies before and during the initial therapeutic period after surgical intervention. A prospective observational study was carried out involving 83 hospitalized calves up to an age of 7 mo, which required surgical intervention for reasons of an acute abdominal emergency such as gastrointestinal ileus or peritonitis. Plasma l-lactate (L-LAC) concentrations were determined immediately before initiation of surgery and 6, 12, 24, 48, and 72 h later. The outcome of calves was evaluated 3 mo after discharge by a phone call to the farmer, and a positive outcome was defined if the calf was still alive and the owner was satisfied with the animal's postsurgical progress. A total of 29% of calves were discharged from the hospital and the proportion of calves with a positive outcome after the 3-mo period was 24%. At all sampling times during the first 48 h after initiation of surgical intervention, calves with a negative outcome had significantly higher L-LAC than calves with a positive outcome. A binary logistic regression analysis indicated that the odds for a negative outcome during the 3-mo observation period increased by a factor of 1.23 [95% confidence interval (CI): 1.04-1.44] for every mmol/L increase of L-LAC before initiation of surgical intervention, but by a factor of 5.29 (95% CI: 1.69-16.6) and 5.92 (95% CI: 1.29-27.3) at 12 and 24 h, respectively. The largest area under the receiver operating characteristic curve for L-LAC was observed at 12 h (0.91; 95% CI: 0.83-0.99), and a cut-point of 2.75 mmol/L was identified that had a sensitivity and specificity for predicting a negative outcome of 68 and 100%, respectively. In conclusion, persistent hyper-l-lactatemia during the early postoperative period is a more reliable indicator for a negative outcome in calves with acute surgical abdominal emergencies than hyper-l-lactatemia before initiation of surgical intervention. Postoperative measurements of L-LAC are therefore a clinically useful tool to identify patients with an increased risk for a negative outcome at an early stage after surgical intervention was carried out.

Prognostic value of preoperative plasma l-lactate concentrations in calves with acute abdominal emergencies

Acute abdominal emergencies in calves due to abomasal disorders, gastrointestinal ileus, or peritonitis are characterized by a rapid disease progression and usually require immediate surgical intervention. Those conditions are associated with a guarded prognosis, and the aim of the present study was to assess the prognostic relevance of preoperatively measured plasma l-lactate concentrations (l-LAC) in a large study population of calves with a broad spectrum of acute abdominal emergencies. For the purpose of this study, the medical records of 587 calves admitted to a veterinary teaching hospital over a 10-yr period were analyzed retrospectively. Plasma l-LAC was measured as part of a routinely performed biochemistry panel before initiation of surgical intervention. Hyper-l-lactatemia (plasma l-LAC >2.2 mmol/L) was evident in 75% of calves, and the overall survival rate until hospital discharge was 31%. Calves with a negative outcome were younger (median: 3.4 vs. 6 wk) and had higher plasma l-LAC (median: 4.96 vs. 3.09 mmol/L) than calves with a positive outcome. At the individual diagnosis level, l-LAC was associated with mortality in calves with a diagnosis of mesenteric torsion, right-sided dilated abomasum, small intestinal volvulus, or paralytic ileus, but not in calves suffering from peritonitis, malformations, abomasal volvulus, bloat, or small intestinal intussusceptions. Considering the whole study population, the area under the receiver operating characteristic (ROC) curve for plasma l-LAC was 0.66 [95% confidence interval (CI): 0.61-0.70]. A classification tree analysis indicated that l-LAC >8.84 mmol/L and age categories of <3 wk and <1 wk were independent predictors of mortality. The area under the ROC curve of this model was 0.75 (95% CI: 0.71-0.79) and the resulting sensitivity and specificity for the prediction of nonsurvival at the optimal probability cut-point of 0.62 were 67.7 and 76.6%, respectively. In conclusion, hyper-l-lactatemia is common in calves suffering from acute abdominal emergencies. Markedly increased plasma l-LAC is associated with an increased mortality risk, but it is not possible to reliably predict the outcome of affected calves based on a single, preoperative measurement. However, a clinically important finding of this study was that the ability to predict a negative outcome is improved when the age of the calf is considered in addition to plasma l-LAC.

Utility of admission lactate concentration, lactate variables, and shock index in outcome assessment in dogs diagnosed with shock

OBJECTIVE

To determine whether admission venous plasma lactate concentration, calculated lactate variables, or shock index (SI) could discriminate hospital survivors from nonsurvivors in dogs admitted with shock.

DESIGN

Prospective investigation performed over a 19-month period.

SETTING

Large urban private teaching hospital.

ANIMALS

Twenty-three dogs consecutively admitted to the ICU from January 2008 to July 2009 with initial peripheral venous plasma lactate concentration >2 mmol/L (18.0 mg/dL) and clinical and hemodynamic parameters consistent with shock.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Heart rate, systolic blood pressure, and venous plasma lactate concentrations were serially recorded at predefined time points and used to calculate SI (SI = heart rate/systolic blood pressure) and lactate variables, including lactime (time lactate > 2.0 mmol/L), lactate clearance ([lactate_initial - lactate_delayed ]/lactate_initial × 100), and LAC_AREA (area under the lactate concentration versus time curve). Primary outcome was survival to discharge. Overall survival rate was 61%. Admission venous plasma lactate concentration did not differ between groups (P = 0.2). Lactime was shorter in survivors versus nonsurvivors (P = 0.02). Lactate clearance at 1, 10, 16, 24, and 36 hours, and final lactate clearance were greater in survivors versus nonsurvivors (P < 0.05). LAC_AREA at time intervals 0-1, 1-4, 4-10, 10-16, 16-24, 24-30, and 30-36 hours was larger in nonsurvivors versus survivors (P < 0.05). Total LAC_AREA did not differ between groups (P = 0.09). Admission SI and time to normalize SI (SI < 0.9) were not different between survivors and nonsurvivors (P > 0.05).

CONCLUSIONS

While admission venous plasma lactate concentration could not discriminate between hospital survivors and nonsurvivors, lactate variables showed clinical utility to predict outcome in dogs with shock. Further studies are needed to determine SI reference ranges and optimal SI cut-off values to improve its prognostic ability in sick dogs.

Preoperative factors associated with resection and anastomosis in horses presenting with strangulating lesions of the small intestine

OBJECTIVE

To determine if preoperative and intraoperative clinical variables correlate with resection and anastomosis (RA) in horses presenting with strangulating small intestinal (SI) lesions.

STUDY DESIGN

Retrospective case series.

ANIMALS

Horses undergoing exploratory celiotomy for a strangulating SI lesion (n = 243).

METHODS

The records of horses undergoing surgical correction for strangulating SI lesions from January 1, 2000 to December 31, 2017 were reviewed. Horses were categorized as treated with RA or not treated with RA. Obtained information included history, signalment, clinical findings, diagnostic test results, intraoperative findings, and survival to discharge. Univariable and multivariable analyses were used to compare data between horses treated with RA vs those not treated with RA (P = .05).

RESULTS

In total, 172 SI lesions were resected, and 71 were not resected. Horses that had gastric reflux at admission to the hospital (odds ratio [OR] 5.56; 95% CI 1.76, 17.59) and horses with amotile SI according to abdominal ultrasonography (OR 9.69; 95% CI 3.09, 30.37) were more likely to undergo RA. Increased difference between peritoneal fluid and blood lactate was higher in horses that underwent RA (OR 1.55; 95% CI 1.12, 2.13). Survival to hospital discharge was lower in the group of horses that underwent RA compared with horses that did not undergo RA.

CONCLUSION

Resection and anastomosis of strangulating SI lesions was associated with several preoperative variables.

CLINICAL SIGNIFICANCE

This study highlights the value of preoperative diagnostic procedures in aiding intraoperative decision making and prognostication in horses presenting with strangulating SI lesions.

Predictive value of plasma and peritoneal creatine kinase in horses with strangulating intestinal lesions

OBJECTIVE

To determine the ability of plasma and peritoneal creatine kinase (CK) to predict the presence of a strangulating lesion in horses presented for colic.

STUDY DESIGN

Prospective clinical study.

ANIMALS

Ten healthy control horses and 61 clinical colic cases.

METHODS

Creatine kinase activity was measured in peritoneal fluid and plasma of 10 healthy horses and 61 horses presenting for colic (40 horses with nonstrangulating lesions and 21 horses with strangulating lesions). Information on other blood and peritoneal fluid variables, signalment, results from the physical examination, outcome, requirement for surgery, and lesion location and type were retrieved from the medical records of horses presenting for colic.

RESULTS

A peritoneal CK cutoff level of 16 IU/L yielded a sensitivity of 95.2% and a specificity of 84.6% (positive predictive value [PPV] = 76.9% and negative predictive value [NPV] = 97%, respectively) for predicting a strangulating lesion. A peritoneal lactate cutoff level of 3.75 mmol/L yielded a sensitivity of 81% and a specificity of 92% (PPV = 85% and NPV = 90%, respectively) for predicting a strangulating lesion.

CONCLUSION

Peritoneal CK concentration was a sensitive indicator of the presence of a strangulating lesion in horses presenting with colic, whereas peritoneal lactate concentration was a more specific indicator.

CLINICAL SIGNIFICANCE

Measuring CK in peritoneal fluid may be a useful adjunct to clinical case presentation to accelerate the diagnosis and definitive treatment of horses presenting with strangulating intestinal lesions, thereby improving their outcome.

Clinical use of plasma lactate concentration. Part 2: Prognostic and diagnostic utility and the clinical management of hyperlactatemia

OBJECTIVE

To review the current literature pertaining to the use of lactate as a prognostic indicator and therapeutic guide, the utility of measuring lactate concentrations in body fluids other than blood or plasma, and the clinical management of hyperlactatemia in dogs, cats, and horses.

DATA SOURCES

Articles were retrieved without date restrictions primarily via PubMed, Scopus, and CAB Abstracts as well as by manual selection.

HUMAN AND VETERINARY DATA SYNTHESIS

Increased plasma lactate concentrations are associated with increased morbidity and mortality. In populations with high mortality, hyperlactatemia is moderately predictive in identifying nonsurvivors. Importantly, eulactatemia predicts survival better than hyperlactatemia predicts death. Consecutive lactate measurements and calculated relative measures appear to outperform single measurements. The use of lactate as a therapeutic guide has shown promising results in people but is relatively uninvestigated in veterinary species. Increased lactate concentrations in body fluids other than blood should raise the index of suspicion for septic or malignant processes. Management of hyperlactatemia should target the underlying cause.

CONCLUSION

Lactate is a valuable triage and risk stratification tool that can be used to separate patients into higher and lower risk categories. The utility of lactate concentration as a therapeutic target and the measurement of lactate in body fluids shows promise but requires further research.

Impact of bacterial translocation in calves with atresia coli

OBJECTIVE

To identify whether enteric bacteria pass into the mesenteric lymph nodes (MLNs) and peritoneal cavity in calves with atresia coli and to evaluate whether the presence of bacterial translocation (BT) has an impact on the success of surgical treatment.

DESIGN

Prospective clinical study.

ANIMALS

Twenty-six client-owned calves.

INTERVENTIONS

During laparotomy, swab samples were collected from the peritoneal cavity and MLNs using a sterile swab stick and were submitted for microbiological analysis.

MEASUREMENTS AND MAIN RESULTS

Bacterial cultures of swab samples revealed that 65% (n = 17) of the calves experienced BT. Of these, 14 calves experienced BT to the MLNs, 9 to the peritoneal cavity, and 5 to both regions. Of the bacteria isolated from the MLNs, 72% (n = 10) were Escherichia coli. Of the samples isolated from the peritoneal fluid, 33% (n = 3) contained E. coli and 33% (n = 3) contained E. coli + coagulase-negative Staphylococcus (CNS). In calves with BT that were discharged (n = 13) and without BT that were discharged (n = 7), the median survival was 30 days; these data were found to be similar in the 2 groups.

CONCLUSIONS

This study revealed that BT is observed in the majority of atresia coli cases. E. coli is more common in BT, and translocation occurs primarily through the lymphatic route. These results suggest that the presence of BT is closely related to the success of the operation for correction of atresia coli.

Assessment of a portable lactate meter for field use in the white rhinoceros (<i>Ceratotherium simum</i>)

Blood lactate is a predictor of mortality in critically ill humans and animals. Handheld lactate meters have the potential to be used in the field to evaluate the condition of severely injured rhinoceroses but have not been compared with laboratory-based methods. Agreement between a handheld lactate meter and a laboratory method was assessed, as was the stability of rhino blood lactate in the anticoagulant sodium fluoride/potassium oxalate (fluoride/oxalate). Blood samples were obtained from 53 white rhinos that had been immobilised for management reasons. Lactate was measured by means of a handheld meter using whole blood in heparin (WBHEP), whole blood in fluoride/oxalate (WBFO) and fluoride/oxalate plasma (PFO). Results were recorded in both blood (BL) and plasma (PL) modes and compared to an established laboratory method for measuring plasma lactate. To assess the stability of lactate over time, blood lactate in fluoride/oxalate was measured on the handheld meter at intervals for up to 91 h. Agreement was best using WBFO in PL mode, with small bias (−0.16), tight 95% limits of agreement (LOA) (−1.46, 1.14) and a Pc (95% CI) of 0.97 (0.92, 0.99). The agreement was improved for all sample types when using the PL mode compared to the blood lactate (BL) mode. Blood lactate was stable in fluoride/oxalate for 91 h, with a mean change from baseline of 0.15 (−0.178, 0.478) mmol/L (mean, 95% CI). The handheld meter was found to be suitable for field use in white rhinos but provided more reliable results with the device in PL mode. Furthermore, rhino blood lactate was found to be stable in fluoride/oxalate for as long as 3 days.

Survival and Evaluation of Clinical and Laboratory Variables as Prognostic Indicators in Horses Hospitilized with Acute Diarrhea: 342 Cases (1995-2015)

A retrospective study was performed on 342 horses with acute diarrhea (equine colitis). Clinical and laboratory data were obtained upon arrival at the equine hospital. The main focus of this study was to find the difference between the clinical and laboratory variables of surviving and deceased acute colitis horses before the beginning of medical treatment, with the aim to provide a better guideline for determining the prognosis of survival. According to this retrospective study the lethality rate of acute equine colitis was 41.93 %. The time interval from the onset of acute diarrhea to the horse being taken to the clinic was significantly longer in the case of horses which had not survived. The heart rate, hematocrit, blood pH, blood hydrogen carbonate concentration, base excess and HCT/TPP ratio were shown to be significantly related to the survival of horses with colitis. Thus, the hematocrit, appeared to be the most relevant predictor of the outcome of acute equine colitis. Body temperature, respiration rate, total plasma protein and white blood cell count, did not show any prognostic significance.

Survival analysis of hypotensive cats admitted to an intensive care unit with or without hyperlactatemia: 39 cases (2005-2011)

OBJECTIVE To examine the association between blood lactate concentration and survival to hospital discharge in critically ill hypotensive cats. DESIGN Retrospective case series. ANIMALS 39 cats admitted to an intensive care unit of a university veterinary hospital between January 2005 and December 2011 for which blood lactate concentration was recorded ≤ 1 hour before or after a Doppler-derived arterial blood pressure measurement ≤ 90 mm Hg (ie, hypotension) was obtained. PROCEDURES Medical records of each cat were reviewed to assess survival to hospital discharge, illness severity, duration of hospitalization, age, body weight, and PCV. Results were compared between hypotensive cats with and without hyperlactatemia (blood lactate concentration ≥ 2.5 mmol/L). RESULTS 6 of 39 (15%) hypotensive cats survived to hospital discharge. Twelve (31%) cats were normolactatemic (blood lactate concentration < 2.5 mmol/L), and 27 (69%) were hyperlactatemic. Hypotensive cats with normolactatemia had a higher blood pressure and higher survival rate than hypotensive cats with hyperlactatemia. Five-day Kaplan-Meier survival rates were 57% for normolactatemic cats and 17% for hyperlactatemic cats. Age, body weight, duration of hospitalization, PCV, and illness severity did not differ significantly between hypotensive cats with and without hyperlactatemia. CONCLUSIONS AND CLINICAL RELEVANCE Hypotensive, normolactatemic cats in an intensive care unit had a significantly greater chance of survival to hospital discharge than their hyperlactatemic counterparts. Blood lactate concentration may be a useful prognostic indicator for this patient population when used in conjunction with other clinical and laboratory findings.

Clinical signs, profound acidemia, hypoglycemia, and hypernatremia are predictive of mortality in 1,400 critically ill neonatal calves with diarrhea

Profound acidemia impairs cellular and organ function and consequently should be associated with an increased risk of mortality in critically ill humans and animals. Neonatal diarrhea in calves can result in potentially serious metabolic derangements including profound acidemia due to strong ion (metabolic) acidosis, hyper-D-lactatemia, hyper-L-lactatemia, azotemia, hypoglycemia, hyperkalemia and hyponatremia. The aim of this retrospective study was to assess the prognostic relevance of clinical and laboratory findings in 1,400 critically ill neonatal calves with diarrhea admitted to a veterinary teaching hospital. The mortality rate was 22%. Classification tree analysis indicated that mortality was associated with clinical signs of neurologic disease, abdominal emergencies, cachexia, orthopedic problems such as septic arthritis, and profound acidemia (jugular venous blood pH < 6.85). When exclusively considering laboratory parameters, classification tree analysis identified plasma glucose concentrations < 3.2 mmol/L, plasma sodium concentrations ≥ 151 mmol/L, serum GGT activity < 31 U/L and a thrombocyte count < 535 G/L as predictors of mortality. However, multivariable logistic regression models based on these laboratory parameters did not have a sufficiently high enough sensitivity (59%) and specificity (79%) to reliably predict treatment outcome. The sensitivity and specificity of jugular venous blood pH < 6.85 were 11% and 97%, respectively, for predicting non-survival in this study population. We conclude that laboratory values (except jugular venous blood pH < 6.85) are of limited value for predicting outcome in critically ill neonatal calves with diarrhea. In contrast, the presence of specific clinical abnormalities provides valuable prognostic information.

Effect of electrolyte supplementation on electrolyte profile in Marwari horses during 20 km moderate intensity riding exercise

The effect of electrolyte supplementation on plasma electrolyte profile in horses in hot environmental conditions was studied using sweat loss and sweat electrolyte concentration. Eleven adult Marwari mares were selected for the study. To develop an electrolyte supplement, 7 mares were given a preliminary 20 km moderate intensity exercise and the electrolyte supplement was designed on basis of their body weight loss and sweat electrolyte concentration during exercise. In the subsequent trials, 4 mares were kept in an exercise control group that did not receive the supplement (ECG), while 3 mares were kept in the exercise supplementation group (ESG) that received the supplement. Four other mares were used as resting controls (RG). ESG mares were daily fed 50 g electrolyte supplement and 150 g supplement orally 1 h before the 20 km trial. Mares of ESG and ECG groups were conferred 3 km trot + canter riding every day in the morning and a 20 km trot + canter ride on every 10th day of the total trial period of 40 days. Blood analysis revealed a significant (P<0.05) decline in plasma calcium and chloride concentrations immediately after exercise in both groups. There was significant less post-exercise decrease of plasma calcium and chloride concentration in ESG mares. Post-exercise plasma sodium concentration was higher (P<0.05) and plasma potassium concentration was lower only in ESG mares (P<0.05) compared to pre-exercise concentrations. The supplement did not affect the physiological responses (heart rate and rectal temperature). However, the changes in plasma sodium, potassium, calcium and chloride concentration were in favour of better performance in supplemented (ESG) mares and advocate sweat-developed electrolyte supplementation in riding mares.

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.

Prognostic Value and Development of a Scoring System in Horses With Systemic Inflammatory Response Syndrome

Background

Despite its widespread use in equine medicine, the clinical value of the systemic inflammatory response syndrome (SIRS) concept in horses remains unknown.

Objectives

To study the prognostic value of measures of SIRS in horses and identify the best model of severe SIRS to predict outcome.

Animals

A total of 479 consecutive adult horse emergency admissions to a private primary referral practice.

Methods

Prospective observational study. All adult horses admitted for emergency treatment over the study period were included. Multivariate logistic regression and stepwise model selection were used.

Results

Each of the 4 SIRS criteria was associated with outcome in this population. Thirty‐one percent of emergency cases had 2 or more abnormal SIRS criteria on admission and were defined as SIRS cases. SIRS was associated with increased odds of death (odds ratio [OR] = 8.22; 95% CI, 4.61–15.18; P < .001), an effect mainly found for acute gastrointestinal cases. SIRS cases were assigned a SIRS score of 2, 3, or 4, according to the number of abnormal SIRS criteria fulfilled on admission, and SIRS3 and SIRS4 cases had increased odds of death compared to SIRS2 cases (OR = 4.45; 95% CI, 1.78–11.15; P = .002). A model of severe SIRS including the SIRS score, blood lactate concentration, and color of the mucous membranes best predicted outcome in this population of horses.

Conclusions and Clinical Importance

Systemic inflammatory response syndrome is associated with an increased risk of death in adult horses presenting with acute gastrointestinal illnesses. The model of severe SIRS proposed in this study could be used to assess the status and prognosis of adult equine emergency admissions.

Effect of Dexamethasone on Resting Blood Lactate Concentrations in Horses

Background

Blood lactate concentration is a marker of tissue perfusion and helps guide therapeutic interventions in critically ill horses. In both humans and dogs, administration of corticosteroids can increase blood lactate concentration, leading to type B hyperlactatemia. This effect could be a consequence of the impact of corticosteroids on glucose metabolism.

Objectives

To investigate the effects of daily IM dexamethasone administration on blood lactate and glucose concentrations in horses.

Animals

Nine healthy adult horses.

Methods

A randomized, blinded, controlled, cross‐over study design was used. Horses were randomly assigned to 1 of 2 groups, either receiving 0.05 mg/kg of dexamethasone IM or an equivalent volume of saline, daily for 7 days. Blood was collected to determine lactate and glucose concentrations at baseline, 2 hours after the daily injections and 24 hours after the last injection.

Results

Dexamethasone treatment had a statistically significant effect on lactate (P = .006) and glucose (P = .033) concentrations. The least squares mean lactate concentration was 0.93 mmol/L (95% CI: 0.87–0.99) in the dexamethasone group compared to 0.71 mmol/L (95% CI: 0.70–0.73) for the saline group. A positive relationship between blood lactate and glucose concentrations was identified, with a 0.07 mmol/L (95% CI: 0.05–0.09) increase in lactate concentration per unit increase in glucose (P < .0001) concentration.

Conclusions and Clinical Importance

Dexamethasone induces statistically significant increases in blood lactate and glucose concentrations in healthy horses. Awareness of the potential for corticosteroids to induce type B hyperlactatemia might be important in the management of critically ill horses receiving dexamethasone.

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

REASONS FOR PERFORMING STUDY

The transverse facial venous sinus (TFVS) can be used for blood collection in horses, but information on the validity of blood values from this site is limited.

OBJECTIVES

To determine if packed cell volume (PCV), total solids (TS) and blood lactate concentrations in blood drawn simultaneously from a TFVS and jugular vein of critically ill horses are correlated and determine the effect of serial TFVS sampling on the same parameters in healthy horses.

STUDY DESIGN

Prospective observational study.

METHODS

Critically ill horses had simultaneous blood samples drawn from a TFVS and jugular vein. Blood was also drawn from the left TFVS and jugular vein from 6 healthy, adult horses q. 6 h for 24 h, then q. 24 h for 72 h. Blood was drawn from the right TFVS and jugular vein q. 24 h for 96 h. All samples were analysed for PCV, TS and blood lactate concentration. Data were analysed with 2-way repeated measures ANOVA. Significance was set at P≤0.05.

RESULTS

There were no significant differences in PCV, TS or blood lactate concentrations of TFVS samples compared with jugular blood in critically ill horses. Serial TFVS sampling in healthy horses had no significant effect on TS or blood lactate concentrations. Although PCV in the TFVS was significantly lower than in jugular blood on serial sampling, the difference was not considered clinically relevant.

CONCLUSIONS

Packed cell volume, TS and blood lactate concentrations were comparable between the TFVS and jugular vein.

Repeated measurements of blood lactate concentration as a prognostic marker in horses with acute colitis evaluated with classification and regression trees (CART) and random forest analysis

The objective of this study was to investigate the prognostic value of single and repeated measurements of blood l-lactate (Lac) and ionised calcium (iCa) concentrations, packed cell volume (PCV) and plasma total protein (TP) concentration in horses with acute colitis. A total of 66 adult horses admitted with acute colitis (<24 h) to a referral hospital in the 2002-2011 period were included. The prognostic value of Lac, iCa, PCV and TP recorded at admission and 6 h post admission was analysed with univariate analysis, logistic regression, classification and regression trees, as well as random forest analysis. Ponies and Icelandic horses made up 59% of the population, whilst the remaining 41% were horses. Blood lactate concentration at admission was the only individual parameter significantly associated with probability of survival to discharge (P < 0.001). In a training sample, a Lac cut-off value of 7 mmol/L had a sensitivity of 0.66 and a specificity of 0.92 in predicting survival. In independent test data, the sensitivity was 0.69 and the specificity was 0.76. At the observed survival rate (38%), the optimal decision tree identified horses as non-survivors when the Lac at admission was ≥4.3 mmol/L and the Lac 6 h post admission stayed at >2 mmol/L (sensitivity, 0.72; specificity, 0.8). In conclusion, blood lactate concentration measured at admission and repeated 6 h later aided the prognostic evaluation of horses with acute colitis in this population with a very high mortality rate. This should allow clinicians to give a more reliable prognosis for the horse.

The area under the curve of L-lactate in neonatal foals from birth to 14 days of age

BACKGROUND

Prior studies have shown the prognostic utility of measuring L-lactate in critically ill neonatal foals, both as single (at admission) and serial measurements. Greater prognostic sensitivity and specificity may be achieved by use of the area under the L-lactate versus time curve (LACArea ) over the first 24 hours of hospitalization, which captures both severity and duration of hyperlactatemia. Prior to application of this concept in sick equine neonates, a reference interval for LACArea should be determined.

METHODS

The concentration of lactate [LAC] was measured in blood obtained via direct jugular venipuncture from clinically normal foals on Days 1 (birth-24 h of age), 3, 7, and 14 following birth at 6-hour intervals for each 24-hour period. LACArea was calculated using the trapezoidal method. Differences in LACArea by Day were determined by MANOVA with a priori Bonferroni correction, P ≤ 0.05.

RESULTS

LACArea differed by Day (P = 0.001), being largest on Day 1, followed by Day 3. Days 7 and 14 were smallest and not different from each other.

CONCLUSION

LACArea decreases substantially and predictably over the first week of life in normal neonatal foals. Knowing how LACArea normally changes over the first 2 weeks of life will aid in future study of LACArea as it applies to sick neonatal foals, allowing for consideration of maturational changes potentially unrelated to disease.

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.