An in vitro evaluation of storage media for the preservation of canine packed red blood cells

The effect of four different red blood cell storage media on in vitro parameters of stored canine red blood cells was studied. The storage media included citrate-phosphate-dextrose-adenine (CPDA-1), two additive solutions, and an additive solution modified by the addition of plasma. Biochemical and hematologic parameters, including red cell adenosine triphosphate (ATP); 2,3-diphosphoglycerate (2,3-DPG); pH; percent hemolysis; and supernatant sodium, potassium, and glucose were assessed immediately following preparation of the red cell concentrate and after 35 and 42 days of storage at 4 degrees C. All parameters changed significantly (p < 0.05) during storage. Significant differences due to effect of the storage media were also seen at each time period. After 35 days and 42 days of storage, CPDA-1 maintained the highest pH, potassium, and sodium values, and had the lowest 2,3-DPG, ATP (p=0.052), and glucose values. No differences were seen in hemolysis after 35 days of storage. No additional benefit was noted from the addition of plasma to the additive solution. The additive solutions compared favorably with CPDA-1.     

Pseudomonas fluorescens contamination of a feline packed red blood cell unit and studies of canine units

Background: While screening programs have reduced the risk of infectious disease transmission by donors in human and veterinary blood banking, bacterial contamination of blood products has emerged as a major complication in human medicine. Objectives: To describe a Pseudomonas fluorescens (Pf)‐contaminated feline packed RBC (pRBC) unit and experimentally investigate Pf‐contaminated canine pRBCs. Methods: Canine pRBCs were inoculated with Pf‐rich pRBCs from the sentinel feline unit and stored at 4°C or 20°C for 72 hours. Aliquots from the pRBCs were serially evaluated by microscopy, culture, and a eubacterial 16S rRNA real‐time PCR assay. Results: One Pf‐contaminated feline unit turned black after 22 days of storage and was removed from the blood bank; a source was not found, and no other contaminated units were identified. Canine pRBCs spiked with 5 or 25 μL of the sentinel unit became culture‐ and/or 16S PCR‐positive at ≥8 hours at 20°C and 48 hours at 4°C and developed a color change at ≥24 hours. Sensitivity studies indicated that without incubation, inoculation of ≥100 μL Pf‐rich pRBCs was necessary for a positive 16S PCR test result. Conclusions: P. fluorescens grows in stored pRBCs slowly at 4°C and rapidly at 20°C. Screening of blood products for color change, estimating bacterial concentration with microscopy, and 16S PCR testing are simple and fast ways to detect bacteria in stored blood. Aseptic collection, temperature‐controlled storage, and regular visual monitoring of stored units is recommended. Discolored units should not be transfused, but examined for bacterial contamination or other blood product quality problems.     

Prognostic value of blood lactate, blood glucose, and hematocrit in canine babesiosis

Canine babesiosis typically causes hemolytic anemia but also can result in multiple organ dysfunction. Human patients with severe disease often have persistent hyperlactatemia, and blood lactate concentration is correlated with survival rate. In dogs, blood lactate concentration has been shown to be of prognostic value in patients with gastric dilatation-volvulus and in dogs admitted to intensive care units. Serial blood lactate and glucose concentrations and hematocrit on admission were determined in 90 dogs with naturally occurring, severe or complicated canine babesiosis. Forty-five dogs (50%) had hyperlactatemia (blood lactate concentration >22.5 mg/dL) and 20 (22.2%) had hypoglycemia (blood glucose concentration <59.4 mg/dL) at presentation. Measurements significantly associated with mortality were hypoglycemia on admission, blood lactate concentration >45 mg/dL on admission, blood lactate concentration >22.5 mg/dL at 8, 16, and 24 hours after admission, and increase or <50% decrease in blood lactate concentration within 8 and 16 hours after admission. Blood lactate concentration persistently >40 mg/dL indicated a very poor prognosis. We conclude that serial blood lactate measurements are useful in predicting survival in dogs with severe and complicated canine babesiosis.     

In vitro lysis and acute transfusion reactions with hemolysis caused by inappropriate storage of canine red blood cell products

Background: Transfusion of red blood cell (RBC) products carries considerable risk for adverse reactions, including life‐threatening hemolytic reactions. Objective: To report the occurrence and investigation of life‐threatening acute transfusion reactions with hemolysis in dogs likely related to inappropriate blood product storage. Animals: Four dogs with acute transfusion reactions and other recipients of blood products. Methods: Medical records were reviewed from 4 dogs with suspected acute hemolytic transfusion reactions after receiving RBC products at a veterinary clinic over a 1‐month period. Medical records of other animals receiving blood products in the same time period also were reviewed. Blood compatibility and product quality were assessed, subsequent transfusions were closely monitored, and products were diligently audited. Results: During or immediately after RBC product transfusion, 4 dogs developed hemolysis, hemoglobinuria, or both. Two dogs died and 1 was euthanized because of progressive clinical signs compatible with an acute hemolytic transfusion reaction. Blood type and blood compatibility were confirmed. RBC units from 2 blood banks were found to be hemolyzed after storage in the clinic's refrigerator; no bacterial contamination was identified. After obtaining a new refrigerator dedicated to blood product storage, the problem of hemolyzed units and acute transfusion reactions with hemolysis completely resolved. Conclusions: Acute life‐threatening transfusion reactions can be caused by inappropriate storage of RBC products. In addition to infectious disease screening and ensuring blood‐type compatibility, quality assessment of blood products, appropriate collection, processing, and storage techniques as well as recipient monitoring are critical to provide safe, effective transfusions.     

A clinical comparison between a non‐invasive blood pressure monitor using high definition oscillometry (Memodiagnostic MD 15/90 Pro) and invasive arterial blood pressure measurement in anaesthetized dogs

ObjectiveTo compare high definition oscillometry (HDO) to invasive blood pressure measurement in anaesthetized dogs.Study designProspective, clinical trial.AnimalsFifty dogs weighing 1.95–79 kg (mean 23.5 kg).Materials and methodsAnaesthetic and peri–anaesthetic management was chosen according to each dog's physical status and anaesthetist's preference. Direct arterial blood pressure measurements were performed using a catheter placed in the dorsal pedal artery and an electronic pressure transducer connected to a multiparameter monitor. Non–invasive blood pressure measurements were performed using an appropriately sized cuff placed around the tail base. Comparisons between the two methods were made using Bland and Altman plots. The data are reported as mean bias (lower, upper limits of agreement). Further analysis was performed after separating the data into the following categories based on invasive mean arterial blood pressure (MAP): high (MAP > 100 mmHg), medium (70 mmHg < MAP < 100 mmHg) and low (MAP < 70 mmHg) blood pressure (BP). The two methods were compared as used clinically.ResultsEight hundred measurement pairs for invasive and HDO BP readings were compared. Overall, the HDO measured lower values for SAP and DAP but higher for MAP than the invasive method. The lowest bias (upper, lower limits of agreement) were obtained for MAP, ?1 (?22, 19) mmHg. The biggest discrepancy between the methods was reflected by a large bias (limits of agreement) 5 (?34, 45) mmHg, was for SAP. The results for DAP were between those for SAP and MAP with a bias (limits of agreement) of 3 (?20, 27) mmHg. When the values were separated into the pressure range categories the HDO measured higher in the high, medium and low BP groups, with the exception of SAP in the low BP group.ConclusionsWhen considering the mean bias, the accuracy of HDO compared well with direct arterial blood pressure, but the precision was poor, as determined by wide limits of agreement.Clinical relevanceUsing trends and serial measurements rather than a single measurement for clinical decision making is recommended with both methods, when used as reported here.     

Accuracy of a portable blood gas analyzer incorporating optodes for canine blood

The accuracy of a portable blood gas analyzer (OPTI 1) was evaluated using canine blood and aqueous control solutions. Sixty-four arterial blood samples were collected from 11 anesthetized dogs and were analyzed for pH, partial pressure of carbon dioxide (PCO2) partial pressure of oxygen (PO2), and bicarbonate concentration ([HCO3-]) values by the OPTI 1 and a conventional blood gas analyzer (GASTAT 3). The conventional analyzer was considered as a standard against which the OPTI 1 was evaluated. Comparison of OPTI 1 results with those of GASTAT 3 by linear regression analysis revealed a high degree of correlation with the GASTAT 3 (r = .90-.91). The mean +/- SD of the differences between OPTI 1 and GASTAT 3 values was -0.008 +/- 0.017 for pH, -0.88 +/- 3.33 mm Hg for PCO2, 3.71 +/- 6.98 mm Hg for PO2, and -0.34 +/- 1.45 mEq/L for [HCO3-]. No statistically significant difference was found between the OPTI 1 and the GASTAT 3. Agreement between these 2 methods is within clinically acceptable ranges for pH, PCO2, PO2, and [HCO3-]. The coefficients of variation for measured pH, PCO2, and PO2 values of 3 aqueous control solutions (acidic, normal, and alkalotic) analyzed by the OPTI 1 ranged from 0.047 to 0.072% for pH, 0.78 to 1.81% for PCO2, and 0.73 to 2.77% for PO2. The OPTI 1 is concluded to provide canine blood gas analysis with an accuracy that is comparable with that of conventional benchtop blood gas analyzers.     

Agreement between noninvasive oscillometric and invasive blood pressure measurements in isoflurane-anesthetized guinea pigs (Cavia porcellus)

ObjectiveTo assess the agreement between an oscillometric device and invasive blood pressure (IBP) measurements in anesthetized healthy adult guinea pigs.Study designProspective experimental study.AnimalsA total of eight adult Hartley guinea pigs.MethodsAll animals were anesthetized; a carotid artery was surgically exposed and catheterized for IBP measurements. A size 1 cuff placed on the right thoracic limb was connected to an oscillometric device for noninvasive blood pressure (NIBP) assessment. Concurrent pairs of systolic (SAP), diastolic (DAP) and mean (MAP) arterial pressures were recorded simultaneously with both methods every 3 minutes for 30 minutes. Agreement between IBP and NIBP measurements was determined using the Bland–Altman method, considering the recommended standards for the validation of NIBP measurement devices proposed by the American College of Veterinary Internal Medicine (ACVIM).ResultsThe bias and the 95% limits of agreement were: –14 (–31 to 3) mmHg, –2 (–14 to 10) mmHg and –1 (–13 to 11) mmHg for SAP, DAP and MAP, respectively.Conclusions and clinical relevanceThe oscillometric device used in this study to measure NIBP did not meet ACVIM criteria for validation. It showed good agreement for DAP and MAP but not for SAP measurements. Considering the small size of these animals and the resulting difficulty in performing percutaneous arterial catheterization, this device might be a useful tool to assess MAP and DAP during anesthetic procedures in adult guinea pigs.     

Evaluation of the agreement of two oscillometric blood pressure devices with invasive blood pressure in anaesthetized chimpanzees (Pan troglodytes)

ObjectiveTo evaluate the agreement of two noninvasive blood pressure devices: a human device with the cuff placed on the wrist (Omron R1) and a veterinary device with the cuff placed on the upper brachium (Surgivet Advisor Vital Signs Monitor) with invasive blood pressure (IBP) measurement in anaesthetized chimpanzees.Study designProspective clinical study.AnimalsA convenience sample of 11 adult chimpanzees undergoing anaesthesia for translocation and routine health checks.MethodsSystolic (SAP) and diastolic arterial pressures (DAP) were continuously recorded via a transducer connected to a femoral artery cannula, and at 5 minute intervals from the two oscillometric devices. Agreement was explored using Bland-Altman analysis and bias defined as the mean difference between the two measurement methods. Spearman correlation coefficients were calculated. Significance was set at p < 0.05.ResultsBias and standard deviation for the Surgivet compared with IBP were 8.6 ± 18 for SAP and 8.4 ± 9.9 for DAP, showing a significant underestimation of both variables. Limits of agreement (LOA) were from –27 to 44 for SAP and from –11 to 28 for DAP. Correlation coefficients between the Surgivet and IBP values were 0.86 for SAP and 0.85 for DAP (p < 0.0001). Bias and standard deviation for the Omron compared with the IBP were –21 ± 25 for SAP and –18 ± 15 for DAP, showing a significant overestimation of both variables. LOA were from –70 to –28 for SAP and from –47 to 11 for DAP. Spearman correlation coefficients between the Omron and IBP values were 0.64 for SAP and 0.72 for DAP (p < 0.0001).Conclusions and clinical relevanceAlthough neither device met all the criteria for device validation, the Surgivet presented better agreement with IBP values than the Omron in adult anaesthetized chimpanzees.     

Evaluation of the utility and accuracy of body fluids containing red blood cells to determine canine and feline blood types

Objective

To examine the accuracy of using body fluids macroscopically suspected to contain erythrocytes to determine the blood type in dogs and cats by use of an immunochromatographic cartridge (ICC), compared to systemic blood as the reference standard.

Design

Prospective study.

Setting

University teaching hospital.

Animals

Thirty client-owned dogs and 8 cats.

Interventions

Dogs and cats with a sanguineous or serosanguineous body fluid (SBF) that also required a blood sample were eligible for inclusion. PCV and blood type were determined in all blood and fluid samples. For body fluids with a low PCV and discordant blood type results compared to systemic blood, sample concentration and repeat blood typing from the fluid was performed when enough sample was available.

Measurement and Main Results

Body fluid samples consisted of 16 pleural (11 dogs; 5 cats), 12 peritoneal (10 dogs; 2 cats), and 4 canine pericardial effusions, 3 urine samples, and 1 each of feces and epistaxis from dogs and a seroma sample from a cat. Median (range) manual PCV of blood and fluid samples was 34% (14%–66%) and 6% (0.5%–70%) for dogs and 28% (14%–48%) and 14% (0.5%–19%) for cats, respectively. Dogs were correctly classified as being DEA 1 negative, DEA 1 positive, and DEA 1 weak positive when using body fluid for blood typing 13 of 14, 4 of 9, and 5 of 7, respectively. All reference blood type to fluid blood type (FBT) discordant results had a body fluid PCV equal to or below 2%. Subsequently concentrated body fluid samples had a PCV above 8% and repeat FBT matched reference blood type (RBT). All cats were classified as type A by all RBTs and FBTs.

Conclusions

Body fluids containing erythrocytes may be utilized to blood type dogs if sufficiently concentrated and type A cats.