Acid-base status in the avian patient using a portable point-of-care analyzer

Responses of the blood acid-base balance and blood plasma metabolomics of broiler chickens after change to diets with high free amino acid levels

Free amino acids (AA) are needed to fulfill the AA requirements of broiler chickens in diets low in CP. This study investigated whether the acid-base balance and the blood plasma metabolome are affected immediately after a change to diets with high free AA levels. Male broiler chickens received a starter diet with 164 g CP/kg and 80 g soy protein isolate/kg until d 7 post-hatch. From this day on, birds were offered a diet almost identical to the starter diet (0FAA) or 2 diets with 50% (50FAA) or 100% (100FAA) of the digestible AA from soy protein isolate substituted with free AA. Blood was sampled to determine the acid-base status and for untargeted metabolomics analysis on d 0, 1, 2, 4, 7, and 14 and d 1, 7, and 14 after diet change, respectively (n = 14 birds/treatment). Compared to 0FAA, blood pH was decreased on d 4 and 7 for 100FAA and on d 4 for 50FAA (P ≤ 0.019). On d 4, 7, and 14, bicarbonate, base excess, and total carbon dioxide were lower for 100FAA than for 0FAA (P ≤ 0.006). The partial pressure of carbon dioxide was higher for 50FAA than for 0FAA on d 4 (P = 0.047). Compared to 0FAA, chloride was higher for 100FAA on d 1, 2, 4, 7, and 14, and for 50FAA on d 1, 2, and 4 (P ≤ 0.030). In the metabolomics assay, 602, 463, and 302 metabolites were affected by treatment on d 1, 7, and 14, respectively (P < 0.050), but they did not indicate that metabolic pathways were affected. Flavonoids were the most consistently affected category of metabolites. The results indicated a metabolic acidosis for 100FAA from d 4 to 7 and a respiratory acidosis for 50FAA on d 4 after diet change. These types of acidosis were compensated later on in the experiment. The metabolomics analysis did not indicate that high free AA inclusion affected metabolic pathways.

Whole blood gas and biochemical reference intervals for Lohmann Silver layers

The blood gas and biochemical reference range established with i-STAT clinical analyzer in avian has become common, however, the reference value for various laying hen lines is limited. Therefore, blood gas and biochemical reference intervals will be established for Lohmann Silver layers in the pre- and post-laying periods. The blood sample was collected at a 4-wk interval. A total of 230 Lohmann Silver layers including 80 pullets (5–17 wk) and 150 laying hens (21–37 wk) were collected for whole blood measurement with the i-STAT clinical analyzer. The CG8+ cartridge provides values of the following 13 parameters: sodium (Na mmol/L), potassium (K mmol/L), ionized calcium (iCa mmol/L), glucose (Glu mg/dL), hematocrit (Hct% Packed Cell Volume [PCV]), pH, partial pressure carbon dioxide (PCO₂ mm Hg), partial pressure oxygen (PO₂ mm Hg), total concentration carbon dioxide (TCO₂ mmol/L), bicarbonate (HCO₃ mmol/L), base excess (BE mmol/L), oxygen saturation (sO₂%), and hemoglobin (Hb g/dL). The correlation of these parameters and the effect of physiological status were investigated. The reference value interval was established with a reference value advisor for pre-laying and post-laying birds. Correlations were found to be statistically significant, especially between BE and HCO₃ and TCO₂. Besides, values in Na, iCa, K, Hct, Hb, sO₂ differed significantly between the pre- and post-laying periods. Data in this study might serve as important information for facilitating the genetic selection and assessing the health of Lohmann Silver laying hens.

Venous Blood Analytes and Osmolality of Rehabilitated Juvenile Black-bellied Whistling Ducks (Dendrocygna autumnalis)

Venous blood samples were collected from 129 apparently healthy, rehabilitated juvenile black-bellied whistling ducks (Dendrocygna autumnalis) immediately before release from rehabilitation. Blood gas, electrolyte, and select biochemical and hematologic values were analyzed by using a point-of-care analyzer, and complete blood cell counts and osmolality were determined. Most biochemical analyte values were distributed parametrically, while most hematologic values were nonparametrically distributed. Calculated osmolality values were in poor agreement with measured osmolality values, and values of packed cell volume had poor agreement with hematocrit values determined with the i-STAT 1. The physiologic values reported provide vital information to assess individual duck health and guide fluid therapy in captivity and may prove useful to assess free-living population health of this duck species.

Comparison of a Point-of-care Cholesterol Meter With a Reference Laboratory Analyzer in Companion Psittaciformes

Hypercholesterolemia is common in captive Psittaciformes. A point-of-care cholesterol analyzer would be useful to monitor hypercholesterolemia in psittacine birds. We compare a point-of-care cholesterol analyzer (PTS-Diagnostics CardioChek) with a reference laboratory analyzer (Roche Cobas c501) and provide initial assessment of precision and accuracy. A prospective method comparison study was designed to compare the CardioChek and Cobas c501 by assessment of clinical and analytical agreement using Passing-Bablock regression analysis and difference plots. Initial accuracy was assessed by running cholesterol standards, and initial precision was assessed by calculating between-run coefficient of variation on samples from selected birds. A total of 42 psittacine birds were sampled. No significant constant bias was found between the Cobas and CardioChek. However, a significant negative proportional bias was evident, suggesting that the point-of-care analyzer tended to underestimate cholesterol values. Lipemia and hemolysis had strong effects on increasing bias. Hematocrit, glucose level, and genus had no significant impact on bias, controlling for lipemia and hemolysis. Accuracy of the CardioCheck was suboptimal to that of the Cobas, but precision was good. When defining hypercholesterolemia as >8 mmol/L (309 mg/dL), the CardioChek had a sensitivity of 57% and specificity of 96%. There was neither analytical nor clinical agreement between the CardioChek and Cobas c501. Values obtained from the CardioChek cannot be used to determine or monitor hypercholesterolemia in parrots in the absence of analyzer-specific reference intervals.

BLOOD GAS, LACTATE, AND HEMATOLOGY EFFECTS OF VENIPUNCTURE TIMING AND LOCATION AFTER MIST-NET CAPTURE OF MOURNING DOVES (ZENAIDA MACROURA), BOAT-TAILED GRACKLES (QUISCALUS MAJOR), AND HOUSE SPARROWS (PASSER DOMESTICUS)

Venous blood gas partial pressures, pH, bicarbonate and lactate concentrations, packed cell volume, white blood cell differential counts, and heterophil/lymphocyte ratios were measured from Mourning Doves (Zenaida macroura), Boat-tailed Grackles (Quiscalus major), and House Sparrows (Passer domesticus). Birds were bled promptly after mist-net capture and banding or following a targeted delay of 45-60 min, in order to assess the impacts of a brief holding period commonly practiced in large-scale bird banding operations. Additionally, effects of venipuncture location (basilic [=ulnar] vein versus jugular vein) were evaluated in male Boat-tailed Grackles sampled promptly after capture and banding. All comparisons were with unpaired samples; no birds were subjected to more than one venipuncture. All three species exhibited moderate improvements in blood gas and acid-base status after the delay, with reductions in lactate concentrations with or without concurrent increases in pH and bicarbonate. Boat-tailed Grackles exhibited an increased proportion of heterophils in the differential white blood cell count following a delay in sampling, suggestive of a stress leukogram. There were no significant differences between basilic and jugular venipuncture results from male Boat-tailed Grackles. Most metabolic, respiratory, and acid-base alterations were minor, but a small number of birds exhibited values (e.g., temperature-corrected pH <7.3, lactate >10 mmol/L) that could be of concern if combined with other adverse conditions. For such birds, a short delay between capture and processing could benefit their blood gas and acid-base status, although loss of time foraging or feeding young and greater activation of the hypophyseal-pituitary-adrenal axis are additional considerations.

Commercial Hy-Line W-36 pullet and laying hen venous blood gas and chemistry profiles utilizing the portable i-STAT®1 analyzer

Venous blood gas and chemistry reference ranges were determined for commercial Hy-Line W-36 pullets and laying hens utilizing the portable i-STAT®1 analyzer and CG8+ cartridges. A total of 632 samples were analyzed from birds between 4 and 110 wk of age. Reference ranges were established for pullets (4 to 15 wk), first cycle laying hens (20 to 68 wk), and second cycle (post molt) laying hens (70 to 110 wk) for the following traits: sodium (Na mmol/L), potassium (K mmol/L), ionized calcium (iCa mmol/L), glucose (Glu mg/dl), hematocrit (Hct% Packed Cell Volume [PCV]), pH, partial pressure carbon dioxide (PCO₂ mm Hg), partial pressure oxygen (PO₂ mm Hg), total concentration carbon dioxide (TCO₂ mmol/L), bicarbonate (HCO₃ mmol/L), base excess (BE mmol/L), oxygen saturation (sO₂%), and hemoglobin (Hb g/dl). Data were analyzed using ANOVA to investigate the effect of production status as categorized by bird age. Trait relationships were evaluated by linear correlation and their spectral decomposition. All traits differed significantly among pullets and mature laying hens in both first and second lay cycles. Levels for K, iCa, Hct, pH, TCO₂, HCO₃, BE, sO₂, and Hb differed significantly between first cycle and second cycle laying hens. Many venous blood gas and chemistry parameters were significantly correlated. The first 3 eigenvalues explained ∼2/3 of total variation. The first 2 principal components (PC) explained 51% of the total variation and indicated acid-balance and relationship between blood O₂ and CO₂. The third PC explained 16% of variation and seems to be related to blood iCa. Establishing reference ranges for pullet and laying hen blood gas and chemistry with the i-STAT®1 handheld unit provides a mechanism to further investigate pullet and layer physiology, evaluate metabolic disturbances, and may potentially serve as a means to select breeder candidates with optimal blood gas or chemistry levels on-farm.

Impact of Delayed Analysis in Avian Blood Biochemical Values Measured With the Abaxis VetScan VS2

For biochemical analysis with a point-of-care biochemical analyzer, standard procedure is to analyze the sample as rapidly as possible (<1 hour) after venipuncture to minimize any changes in analyte concentrations that might occur over time. However, under some circumstances, such as when collecting blood at remote field sites, a longer delay may be unavoidable. This study evaluates the effect of delayed analysis time under unrefrigerated conditions on avian (psittacine) biochemical analyte concentrations obtained with the VetScan VS2 using Avian/Reptilian Profile Plus rotors. Venipuncture was performed on a group of 36 psittacine birds as part of routine health checks in a research aviary (Texas A&M University, College of Veterinary Medicine, College Station, TX, USA). Whole blood was kept at room temperature and analyzed at 4 time intervals: <1, 3, 6, and 24 hours after venipuncture. At 3 hours or less after collection, most biochemical parameters changed by <2%, with the exception of phosphorus (decrease of about -9%). Major increases by 24 hours after collection were observed in phosphorus (+67%) and potassium (+103%) concentrations, whereas aspartate aminotransferase (AST), uric acid, glucose, and sodium concentrations also showed statistically significant changes. Our results suggest that accurate information from analyses using the VetScan VS2 may be obtained for up to 3 hours after venipuncture without refrigeration, but researchers and clinicians do need to exercise care when interpreting blood chemistry analyte concentrations obtained after multihour delays between venipuncture and sample analysis.

Assessment of the accuracy and precision of the i-Smart 30 VET Electrolyte Analyzer in dogs, cats, cattle and pigs

BACKGROUND

Performance evaluation of point-of-care (POC) electrolyte analyzers is essential for determining their precision and accuracy in clinical practice.

OBJECTIVE

The purpose of this study was to validate the i-Smart 30 VET Electrolyte Analyzer for canine, feline, bovine, and porcine samples in comparison with the ion-selective electrolyte analyzer Roche 9180 electrolyte analyzer.

METHODS

A total of 400 heparinized whole blood samples were collected and analyzed by both instruments for sodium, potassium, and chloride concentrations. Within-run, between-day, and total imprecision were evaluated. Statistical analyses included tests for correlation, regression, bias, and total error.

RESULTS

The coefficients of variation (CV) of both within-run and between-day imprecisions in the i-Smart 30 VET ranged from 0.4-1.6%. In addition, total CV (0.3-1.7%) and total error (0.7-3.7%) of the i-Smart 30 VET were acceptable according to the ASVCP guidelines (< 5%). The correlation between the i-Smart 30 VET and the Roche 9180 was excellent (r > .98). There was no proportional error according to the regression (slope ranges 0.92-1.00, 95% CI includes 1.00), but a constant error was detected for sodium concentration in dogs (interval = 0.5), cattle (interval = 3.0), and pigs (interval = 4.0), and for chloride concentration in cats (interval = 1.0). Most of the bias was within 95% CI, and the total error range (0.8-3.5%) was acceptable according to ASVCP guidelines.

CONCLUSION

The i-Smart 30 VET Electrolyte Analyzer provides precise and accurate measurements of sodium, potassium, and chloride concentrations in whole blood samples from dogs, cats, cattle, and pigs.

Lactated Ringer's solution or 0.9% sodium chloride as fluid therapy in pigeons (Columba livia) submitted to humerus osteosynthesis

The study aimed to compare the effects of intraosseous infusion of lactated Ringer's and 0.9% sodium chloride solutions on the electrolytes and acid-base balance in pigeons submitted to humerus osteosynthesis. Eighteen pigeons were undergoing to isoflurane anesthesia by an avalvular circuit system. They were randomly assigned into two groups (n=9) receiving lactated Ringer's solution (LR) or 0.9% sodium chloride (SC), in a continuous infusion rate of 20mL/kg/h, by using an intraosseous catheter into the tibiotarsus during 60-minute anesthetic procedure. Heart rate (HR), and respiratory rate (RR) were measured every 10 min. Venous blood samples were collected at 0, 30 and 60 minutes to analyze blood pH, PvCO2, HCO3 -, Na+ and K+. Blood gases and electrolytes showed respiratory acidosis in both groups during induction, under physical restraint. This acidosis was evidenced by a decrease of pH since 0 min, associated with a compensatory response, observed by increasing of HCO3 - concentration, at 30 and 60 min. It was not observed any changes on Na+ and K+ serum concentrations. According to the results, there is no reason for choosing one of the two solutions, and it could be concluded that both fluid therapy solutions do not promote any impact on acid-base balance and electrolyte concentrations in pigeons submitted to humerus osteosynthesis.