Mark J. Acierno

Effects of ultraviolet radiation on plasma 25-hydroxyvitamin D3 concentrations in corn snakes (Elaphe guttata)

OBJECTIVE To determine whether corn snakes exposed to UVB radiation have increased plasma 25-hydroxyvitamin D3 concentrations, compared with control snakes. ANIMALS 12 corn snakes (Elaphe guttata). PROCEDURES After an acclimation period in individual enclosures, a blood sample was collected from each snake for assessment of plasma 25-hydroxyvitamin D3 concentration. Six snakes were provided with no supplemental lighting, and 6 snakes were exposed to light from 2 full-spectrum coil bulbs. By use of a radiometer-photometer, the UVA and UVB radiation generated by the bulbs were measured in each light-treated enclosure at 3 positions at the basking surface and at 2.54 cm (1 inch) below each bulb surface; the arithmetic mean values for the 3 positions at the basking surface and each individual bulb surface were calculated immediately after the start of the study and at weekly intervals thereafter. At the end of the study (day 28), another blood sample was collected from each snake to determine plasma 25-hydroxyvitamin D3 concentration. RESULTS Mean +/- SD plasma concentration of 25-hydroxyvitamin D3 in snakes that were provided with supplemental lighting (196 +/- 16.73 nmol/L) differed significantly from the value in control snakes (57.17 +/- 15.28 nmol/L). Mean exposure to UVA or UVB did not alter during the 4-week study period, although the amount of UVA recorded near the bulb surfaces did change significantly. CLINICAL RELEVANCE These findings have provided important insight into the appropriate UV radiation requirements for corn snakes. Further investigation will be needed before exact husbandry requirements can be determined.

Agreement between directly measured blood pressure and pressures obtained with three veterinary-specific oscillometric units in cats

OBJECTIVE To determine whether veterinary-specific oscillometric blood pressure units yield measurements that are in good agreement with directly measured blood pressures in cats. DESIGN Evaluation study. ANIMALS 21 cats undergoing routine spaying or neutering. PROCEDURES A 24-gauge catheter was inserted in a dorsal pedal artery, and systolic, diastolic, and mean arterial pressures were directly measured with a validated pressure measurement system. Values were compared with indirect blood pressure measurements obtained with 3 veterinary-specific oscillometric blood pressure units. RESULTS There was poor agreement between indirectly and directly measured blood pressures. For unit 1, bias between indirectly and directly measured values was -14.9 mm Hg (95% limits of agreement [LOA], -52.2 to 22.4 mm Hg), 4.4 mm Hg (95% LOA, -26.0 to 34.8 mm Hg), and -1.3 mm Hg (95% LOA, -26.7 to 24.1 mm Hg) for systolic, diastolic, and mean arterial pressures, respectively. For unit 2, bias was -10.3 mm Hg (95% LOA, -52.9 to 32.2 mm Hg), 13.0 mm Hg (95% LOA, -32.1 to 58.0 mm Hg), and 9.1 mm Hg (95% LOA, -32.9 to 51.2 mm Hg) for systolic, diastolic, and mean arterial pressures, respectively. For unit 3, bias was -13.4 mm Hg (95% LOA, -51.8 to 25.1 mm Hg), 8.0 mm Hg (95% LOA, -25.5 to 41.6 mm Hg), and -3.6 mm Hg (95% LOA, -31.6 to 24.5 mm Hg) for systolic, diastolic, and mean arterial pressures, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that none of the 3 veterinary-specific oscillometric blood pressure units could be recommended for indirect measurement of blood pressure in cats.

Agreement between direct and indirect blood pressure measurements obtained from anesthetized Hispaniolan Amazon parrots

OBJECTIVE To determine the level of agreement between direct and indirect blood pressure measurements obtained from healthy Hispaniolan Amazon parrots (Amazona ventralis) anesthetized with isoflurane. DESIGN Validation study. ANIMALS 16 healthy adult Hispaniolan Amazon parrots. PROCEDURES Parrots were anesthetized, and a 26-gauge, 19-mm catheter was placed percutaneously in the superficial ulnar artery for direct measurement of systolic, mean, and diastolic arterial pressures. Indirect blood pressure measurements were obtained with a Doppler ultrasonic flow detector and an oscillometric unit. The Bland-Altman method was used to compare direct and indirect blood pressure values. RESULTS There was substantial disagreement between direct systolic arterial blood pressure and indirect blood pressure measurements obtained with the Doppler detector from the wing (bias, 24 mm Hg; limits of agreement, -37 to 85 mm Hg) and from the leg (bias, 14 mm Hg; limits of agreement, -14 to 42 mm Hg). Attempts to obtain indirect blood pressure measurements with the oscillometric unit were unsuccessful. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that there was substantial disagreement between indirect blood pressure measurements obtained with a Doppler ultrasonic flow detector in anesthetized Hispaniolan Amazon parrots and directly measured systolic arterial blood pressure.

Measuring statistical agreement between four point of care (POC) lactate meters and a laboratory blood analyzer in cats

The use of blood lactate concentrations as a prognostic indicator and therapeutic gauge in feline medicine has been hindered by the inability to obtain values in a timely manner with minimal quantities of blood. Recently, hand-held point-of-care (POC) lactate meters have become commercially available. The objective of this prospective study was to determine if lactate values produced by three commercially available and one medical grade POC meter were in agreement with a laboratory blood analyzer. Blood samples from 47 cats were collected on presentation to an emergency service and processed on four POC meters and a Stat Profile Critical Care Xpress blood analyzer. The results were analyzed using the Bland–Altman method. The blood lactate values produced by the hospital grade POC meter and one of the commercially POC meters were in good agreement with the Critical Care Xpress blood analyzer. Other commercially available POC meters produced acceptable agreement.

Measuring level of agreement between values obtained by directly measured blood pressure and ultrasonic Doppler flow detector in cats

OBJECTIVE To determine if blood pressure measured with an ultrasonic Doppler flow detector (Doppler) is in good agreement with directly measured blood pressures in anesthetized cats. DESIGN Prospective observational study. SETTING University veterinary teaching hospital. ANIMALS Thirty-nine cats undergoing routine neutering. INTERVENTIONS Cats were divided into 2 groups; 19 cats enrolled in Group A had a 24-Ga catheter inserted into a dorsal pedal artery; 20 cats in Group B had a 20-Ga catheter placed in a femoral artery. In both groups, systolic, diastolic, and mean arterial pressures were directly measured using a validated pressure measurement system. Indirect values were compared against direct blood pressure measurements. RESULTS There was no difference between groups. Overall, there was poor agreement with a significant bias observed between Doppler and directly measured blood pressures. For the systolic arterial pressure the bias was -8.8 with limits of agreements (LOA) of -39.3 and 21.7. For the mean arterial pressure, the bias was 14.0 with LOA of -13.9 and 41.9. For the diastolic arterial pressure, the bias was 27.9 with LOA of -4.4 and 60.2. Methodology, weight, sex, and replicates did not have a significant effect on the difference between indirect and direct measurements in any model. CONCLUSIONS Results suggest poor agreement between Doppler values and directly measured blood pressures in anesthetized cats. Use of Doppler in cats could be misleading and readings should be interpreted with caution in a clinical context.

Continuous Renal Replacement Therapy in Dogs and Cats

Continuous renal replacement therapy (CRRT) is a relatively new extracorporeal blood purification modality that is rapidly gaining acceptance for the treatment of acute kidney injury in cats and dogs. The author has used CRRT for the treatment of leptospirosis, tumor lysis syndrome, heatstroke, pre- and postsurgical support of ureteral obstructions, as well as aminoglycoside and melamine toxicities. As the name implies, CRRT is a slow gradual process, and once treatment begins, patients continue therapy until their renal function returns, they are transitioned to intermittent hemodialysis (IHD), or they are euthanized. Unlike IHD, which is a primarily diffusive therapy, CRRT uses diffusion as well as convection. Because of its efficient use of fluids, CRRT units use prepackaged fluids, eliminating the need for costly water purification systems that are needed for IHD.

Evaluation of the agreement among three handheld blood glucose meters and a laboratory blood analyzer for measurement of blood glucose concentration in Hispaniolan Amazon parrots (Amazona ventralis)

OBJECTIVE To determine the degree of agreement between 3 commercially available point-of-care blood glucose meters and a laboratory analyzer for measurement of blood glucose concentrations in Hispaniolan Amazon parrots (Amazona ventralis). ANIMALS 20 healthy adult Hispaniolan Amazon parrots. PROCEDURES A 26-gauge needle and 3-mL syringe were used to obtain a blood sample (approx 0.5 mL) from a jugular vein of each parrot. Small volumes of blood (0.6 to 1.5 microL) were used to operate each of the blood glucose meters, and the remainder was placed into lithium heparin microtubes and centrifuged. Plasma was harvested and frozen at -30 degrees C. Within 5 days after collection, plasma samples were thawed and plasma glucose concentrations were measured by means of the laboratory analyzer. Agreement between pairs of blood glucose meters and between each blood glucose meter and the laboratory analyzer was evaluated by means of the Bland-Altman method, and limits of agreement (LOA) were calculated. RESULTS None of the results of the 3 blood glucose meters agreed with results of the laboratory analyzer. Each point-of-care blood glucose meter underestimated the blood glucose concentration, and the degree of negative bias was not consistent (meter A bias, -94.9 mg/dL [LOA, -148.0 to -41.7 mg/dL]; meter B bias, -52 mg/dL [LOA, -107.5 to 3.5 mg/dL]; and meter C bias, -78.9 mg/dL [LOA, -137.2 to -20.6 mg/dL]). CONCLUSIONS AND CLINICAL RELEVANCE On the basis of these results, use of handheld blood glucose meters in the diagnosis or treatment of Hispaniolan Amazon parrots and other psittacines cannot be recommended.

Measuring the level of agreement between directly measured blood pressure and pressure readings obtained with a veterinary‐specific oscillometric unit in anesthetized dogs

OBJECTIVE To determine if an oscillometric device optimized for use in dogs produces systolic, diastolic, and mean arterial pressures (MAPs) measurements that are in good agreement with directly obtained pressures DESIGN Prospective study. SETTING University teaching hospital. ANIMALS Twenty-one dogs under general anesthesia for surgical procedures. INTERVENTIONS A 20-Ga catheter was placed into the dorsal pedal artery and systolic, diastolic, and MAPs were directly measured using a validated blood pressure measurement system. Indirect blood pressure measurements were collected using a widely available veterinary oscillometric blood pressure unit. Results obtained by the 2 methods were then compared. MEASUREMENTS AND MAIN RESULTS Agreement between the directly and indirectly measured pressure demonstrated a bias of 9.9 mm Hg and limits of agreement (LOA) 73.7 to -53.9, a bias of -8.9 mm Hg and LOA 23.3 to -41.2, and a bias of -6.3 mm Hg and LOA 28.2 to -40.8 for systolic, diastolic, and MAP, respectively. CONCLUSIONS There was poor agreement between the direct and indirect measured blood pressure measurement systems. Therefore, use of the oscillometric blood pressure unit evaluated in this study for monitoring patients under anesthesia cannot be recommended at this time.

Determinination of plasma osmolality and agreement between measured and calculated values in healthy adult Hispaniolan Amazon parrots (Amazona ventralis).

OBJECTIVE To determine plasma osmolality in healthy adult Hispaniolan Amazon parrots (Amazona ventralis) and validate osmolality equations in these parrots. ANIMALS 20 healthy adult Hispaniolan Amazon parrots. PROCEDURES A blood sample (0.5 mL) was collected from the right jugular vein of each parrot and placed into a lithium heparin microtainer tube. Samples were centrifuged, and plasma was harvested and frozen at -30 degrees C. Samples were thawed, and plasma osmolality was measured in duplicate with a freezing-point depression osmometer. The mean value was calculated for the 2 osmolality measurements. RESULTS Plasma osmolality values were normally distributed, with a mean +/- SD of 326.0 +/- 6.878 mOsm/kg. The equations (2 x [Na(+) + K(+)]) + (glucose/18), which resulted in bias of 2.3333 mOsm/kg and limits of agreement of -7.0940 to 11.7606 mOsm/kg, and (2 x [Na(+) + K(+)]) + (uric acid concentration/16.8) + (glucose concentration/18), which resulted in bias of 5.8117 mOsm/kg and limits of agreement of -14.6640 to 3.0406 mOsm/kg, yielded calculated values that were in good agreement with the measured osmolality. CONCLUSIONS AND CLINICAL RELEVANCE IV administration of large amounts of hypotonic fluids can have catastrophic consequences. Osmolality of the plasma from parrots in this study was significantly higher than that of commercially available prepackaged fluids. Therefore, such fluids should be used with caution in Hispaniolan Amazon parrots as well as other psittacines. Additional studies are needed to determine whether the estimation of osmolality has the same clinical value in psittacines as it does in other animals.

Comparison of directly measured arterial blood pressure at various anatomic locations in anesthetized dogs.

OBJECTIVE To determine whether directly measured arterial blood pressure differs among anatomic locations and whether arterial blood pressure is influenced by body position. ANIMALS 33 client-owned dogs undergoing anesthesia. PROCEDURES Dogs undergoing anesthetic procedures had 20-gauge catheters placed in both the superficial palmar arch and the contralateral dorsal pedal artery (group 1 [n = 20]) or the superficial palmar arch and median sacral artery (group 2 [13]). Dogs were positioned in dorsal recumbency, and mean arterial blood pressure (MAP), systolic arterial blood pressure (SAP), and diastolic arterial blood pressure (DAP) were recorded for both arteries 4 times (2-minute interval between successive measurements). Dogs were positioned in right lateral recumbency, and blood pressure measurements were repeated. RESULTS Differences were detected between pressures measured at the 2 arterial sites in both groups. This was especially true for SAP measurements in group 1, in which hind limb measurements were a mean of 16.12 mm Hg higher than carpus measurements when dogs were in dorsal recumbency and 14.70 mm Hg higher than carpus measurements when dogs were in lateral recumbency. Also, there was significant dispersion about the mean for all SAP, DAP, and MAP measurements. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that arterial blood pressures may be dependent on anatomic location and body position. Because this may affect outcomes of studies conducted to validate indirect blood pressure measurement systems, care must be used when developing future studies or interpreting previous results.