Comparison of direct and indirect blood pressure measurements in anesthetized dogs.

The precision and accuracy of an indirect oscillometric blood pressure measurement technique (Dinamap 8100) was assessed in 11 anesthetized Beagle dogs weighing 8 to 11.5 kg. Direct blood pressure measurements were made by catheterization of the lingual artery, and simultaneous indirect measurements were determined by placing a cuff over the median artery (midradial area). Blood pressure measurements at 2 different planes of anesthesia (light and deep) were recorded in triplicate. At a light plane of anesthesia, the Dinamap 8100 underestimated diastolic and mean arterial pressure, and at a deep anesthetic plane overestimated systolic pressure. The indirect technique had good repeatability of systolic pressures. Regression analysis for the 2 techniques showed excellent correlation (r = 0.93). The results indicate that the indirect oscillometric blood pressure measurement technique provides a good estimate of systolic, diastolic, and mean arterial pressure in dogs weighing 8-11.5 kg.     

Evaluation of an oscillometric blood pressure monitor for use in anesthetized cats

OBJECTIVE: To determine accuracy of an oscillometric blood pressure monitor used over a wide range of pressures in anesthetized cats. DESIGN: Prospective study. ANIMALS: 6 healthy cats. PROCEDURE: 4 female cats and 2 male cats that weighed 2.7 to 4.5 kg (5.9 to 9.9 lb) and were 2 to 8 years old were anesthetized. Blood pressure was measured directly with an arterial catheter placed in the right femoral artery and indirectly from the left antebrachium by use of an oscillometric monitor. A series of diastolic arterial pressure (DAP), mean arterial pressure (MAP), and systolic arterial pressure (SAP) measurements were obtained during hypotension, normotension, and hypertension. Values obtained indirectly and directly were compared. RESULTS: The oscillometric monitor was accurate for DAP and MAP throughout the entire pressure range and met the standards of the Association for the Advancement of Medical Instrumentation (mean +/- SD difference from values obtained directly, < or = 5 +/- 8 mm Hg). The SAP was increasingly underestimated with increasing overall pressure; mean differences from direct measurements were -5.2, -12.1, and -17.7 mm Hg during hypo-, normo-, and hypertension, respectively. Standard deviations for SAP were all < or = 8 mm Hg. The monitor gave readings during all attempts. The direct blood pressure recording system appeared to perform well with neither under- nor overdamping. CONCLUSIONS AND CLINICAL RELEVANCE: Except for a minor underestimation of SAP during normo- and hypertension, the oscillometric monitor yielded reliable and easily obtainable blood pressure measurements in anesthetized cats.     

Evaluation of an Oscillometric Blood Pressure Monitor on Anesthetized Cats and the Effect of Cuff Placement and Fur on Accuracy

Objectives — (1) To determine the usefulness of one specific oscillometric monitor for making indirect measurements of arterial pressure in cats. (2) To determine the difference between two specific cuff placement sites. (3) To determine if clipping the hair beneath the cuff has an affect on the accuracy of oscillometric blood pressure determination.
Study Design — Prospective study comparing the accuracy of the Datascope Passport (Data-scope Corp, Paramus, NJ) with concurrent invasive measurements.
Animals — Six anesthetized domestic felines weighing 4.5 to 5 kg.
Methods — The direct arterial pressure was measured using a cannula placed in the right common carotid artery. Oscillometric cuffs of appropriate size were placed on both thoracic limbs distal to the elbow and both pelvic limbs distal to the stifle. The hair in the areas of cuff placement on the right limbs was clipped circumferentially. Measurements of systolic, diastolic, and mean arterial pressure (MAP) were taken for each site during normotension, hypotension, and hypertension. Comparisons between indirect and direct measurements were made using a parametric analysis of method comparison.
Results — No significant differences were noted when die clipped limbs were compared with the corresponding limbs which were left undipped ( P >.378) or when the thoracic limb measurements were compared widi those of the pelvic limb ( P >.088). There were significant differences ( P <.002) between the two pressure measurement methods for the systolic, diastolic, and mean arterial pressures over all three pressure ranges.
Conclusions — The Datascope Passport did not accurately estimate the invasively measured arterial pressure.
Clinical Relevance — Use of noninvasive blood pressure monitoring equipment is increasing in use in veterinary medicine, and the accuracy of one specific monitor is reported.     

A Comparison of Indirect Blood Pressure Monitoring Techniques in the Anesthetized Cat

Objective —To determine the accuracy of three indirect blood pressure monitoring techniques (oscillometric technique [OS], Doppler [DOP], and optical plethysmography [OP] [blood pressure determined with a pulse oximeter waveform]) when compared with direct arterial pressure measurement in cats. Study Design —Prospective study. Animal Population —Eight healthy (five female, three male), domestic short-hair cats, weighing 3.5 ± 0.8 kg Methods —Cats were anesthetized with isoflurane. The inspired concentration of isoflurane was adjusted to produce mild hypotension (80 to 100 mm Hg direct systolic), moderate hypotension (60 to 80 mm Hg direct systolic), and severe hypotension (<60 mm Hg direct systolic). Indirect pressure measurements were obtained from the thoracic limb and compared with concurrent direct measurement using regression analysis and a modification of Bland and Altman's technique. Results —All three techniques underestimated systolic pressure. OS produced the best prediction of systolic pressure with a bias ± precision of -15.9 ± 8.1 mm Hg. DOP and OP were relatively inaccurate with a bias ± precision of -25 ± 7.4 mm Hg and -25 ± 7.5 mm Hg. All three techniques correlated well with direct pressure with r values of 0.81, 0.88, and 0.88 for OS, DOP, and OP. DOP and OP provided an accurate prediction of direct mean arterial pressure with a bias ± precision of -0.8 ± 6 mm Hg and 0.6 ± 5.5 mm Hg. Correlation was good between DOP and mean arterial pressure with r = 0.89. Correlation was also good between OP and mean arterial pressure with r = 0.90. Conclusions —OS provided the most accurate prediction of direct systolic pressure. DOP and OP provided a good prediction of mean arterial pressure in the cat. Clinical Relevance —All three of these techniques are useful for detecting trends. Direct monitoring of blood pressure should be considered if accurate blood pressure measurement is required.     

Adaptation of human oscillometric blood pressure monitors for use in dogs

Two digital oscillometric human blood pressure measuring devices were modified and evaluated as blood pressure monitors in 12 healthy anesthetized dogs. Direct arterial pressures were measured via cannulation of the dorsal pedal artery and were correlated with indirect measurements through an inflatable cuff placed over the dorsal pedal artery below the hock joint of the contralateral limb. Direct and indirect measurements were compared for systolic, diastolic, and calculated mean arterial pressures. Blood pressure ranges between 215/145 mm of Hg and 65/30 mm of Hg were obtained, using combinations of halothane, phenylephrine, calcium, and IV administered fluids. Machine A was found to be insufficient for clinical application, on the basis of correlation coefficients between direct and indirect pressures of 0.78, 0.65, and 0.74 for systolic, diastolic, and mean arterial pressures, respectively. Higher correlation coefficients between direct and indirect pressures (0.77, 0.87, and 0.87, respectively) were obtained with machine B. The results of the study reported here suggest machine B may be an effective blood pressure monitoring device in anesthetized dogs.     

Cardiovascular effects of a high dose of romifidine in propofol-anesthetized cats

OBJECTIVE: To determine the hemodynamic effects of IM administration of romifidine hydrochloride in propofol-anesthetized cats. ANIMALS: 15 adult domestic shorthair cats. PROCEDURE: Cats were randomly assigned to receive romifidine (0, 400, or 2,000 microg/kg, IM). Cats were anesthetized with propofol and mechanically ventilated with oxygen. The right jugular vein, left carotid artery, and right femoral artery and vein were surgically isolated and catheterized. Heart rate; duration of the PR, QRS, and QT intervals; mean pulmonary artery pressure; mean right atrial pressure; systolic, diastolic, and mean arterial pressures; left ventricular systolic pressure; left ventricular end-diastolic pressure; and cardiac output were monitored. Systemic vascular resistance, rate of change of left ventricular pressure, and rate pressure product were calculated. Arterial and venous blood samples were collected anaerobically for determination of pH and blood gas tensions (Po2 and Pco2). RESULTS: Administration of romifidine at 400 and 2,000 microg/kg, IM, decreased heart rate, cardiac output, rate of change of left ventricular pressure, rate pressure product, and pH. Arterial and pulmonary artery pressures, left ventricular pressure, left ventricular end-diastolic pressure, and right atrial pressure increased and then gradually returned to baseline values. Arterial blood gas values did not change, whereas venous Pco2 increased and venous Po2 decreased. Significant differences between low and high dosages were rare, suggesting that the dosages investigated produced maximal hemodynamic effects. CONCLUSIONS AND CLINICAL RELEVANCE: Romifidine produces cardiovascular effects that are similar to those of other alpha2-agonists. High dosages of romifidine should be used with caution in cats with cardiovascular compromise.     

Cardiopulmonary evaluation of the use of medetomidine hydrochloride in cats.

OBJECTIVE: To evaluate the cardiovascular effects of the alpha2-adrenergic receptor agonist medetomidine hydrochloride in clinically normal cats. ANIMALS: 7 clinically normal cats. PROCEDURE: Cats were anesthetized with isoflurane, and thermodilution catheters were placed for measurement of central venous, pulmonary, and pulmonary capillary wedge pressures and for determination of cardiac output. The dorsal pedal artery was catheterized for measurement of arterial blood pressures and blood gas tensions. Baseline variables were recorded, and medetomidine (20 microg/kg of body weight, IM) was administered. Hemodynamic measurements were repeated 15 and 30 minutes after medetomidine administration. RESULTS: Heart rate, cardiac index, stroke index, rate-pressure product, and right and left ventricular stroke work index significantly decreased from baseline after medetomidine administration, whereas systemic vascular resistance and central venous pressure increased. However, systolic, mean, and diastolic arterial pressures as well as arterial pH, and oxygen and carbon dioxide tensions were not significantly different from baseline values. CONCLUSIONS AND CLINICAL RELEVANCE: When administered alone to clinically normal cats, medetomidine (20 microg/kg, IM) induced a significant decrease in cardiac output, stroke volume, and heart rate. Arterial blood pressures did not increase, which may reflect a predominant central alpha2-adrenergic effect over peripheral vascular effects.     

Effects of sedation with acepromazine maleate and buprenorphine hydrochloride on femoral artery blood flow in healthy dogs

The purpose of this study was to qualify and quantify the femoral artery blood flow by duplex Doppler ultrasonography (DDU) in healthy dogs, before and after the administration of a combination of acepromazine maleate and buprenorphine hydrochloride (ACP-BPN). Seven healthy adult mongrel dogs and three adult beagles were used. Heart rate, arterial blood pressure and measurement of femoral artery blood flow by DDU were also recorded. The DDU measurements were: femoral artery diameter (FAD), peak systolic velocity (PSV), early retrograde (EDV) and end diastolic velocities (EnDV), mean velocity (BMV), pulsatility index (PI), flow velocity integral (FVI) and femoral blood flow (FBF). After 30 min, combination ACP-BPN was administered intramuscularly, and all the measurements were recorded again. The ACP-BPN protocol induced a significant decrease in systolic, mean, and diastolic arterial blood pressure, and heart rate. A significant increase in peak systolic velocity and integral flow velocity integral of the femoral blood were obtained. The Doppler spectra of the blood flow in the femoral artery revealed a spectral dispersion pattern after ACP-BPN administration in all the dogs. These results demonstrate that despite quantitative and qualitative changes, the overall femoral blood flow (FBF) is not significantly modified.     

Doppler ultrasonography and single-fiber laser Doppler flowmetry for measurement of hind limb blood flow in anesthetized horses

OBJECTIVE: To use Doppler ultrasonography and single-fiber laser Doppler flowmetry (LDF) to evaluate blood flow in the dependent and nondependent hind limbs of anesthetized horses and to evaluate changes in femoral arterial blood flow and microvascular skeletal muscle perfusion in response to administration of phenylephrine hydrochloride or dobutamine hydrochloride. ANIMALS: 6 healthy adult horses. PROCEDURE: Horses were anesthetized and positioned in left lateral recumbency. Doppler ultrasonography was used to measure velocity and volumetric flow in the femoral vessels. Single-fiber LDF was used to measure relative microvascular perfusion at a single site in the semimembranosus muscles. Phenylephrine or dobutamine was then administered to decrease or increase femoral arterial blood flow, and changes in blood flow and microvascular perfusion were recorded. RESULTS: Administration of phenylephrine resulted in significant decreases in femoral arterial and venous blood flows and cardiac output and significant increases in mean aortic blood pressure, systemic vascular resistance, and PCV. Administration of dobutamine resulted in significant increases in femoral arterial blood flow, mean aortic blood pressure, and PCV. Significant changes in microvascular perfusion were not detected. CONCLUSION AND CLINICAL RELEVANCE: Results suggest that Doppler ultrasonography and single-fiber LDF can be used to study blood flows in the hind limbs of anesthetized horses. However, further studies are required to determine why changes in femoral arterial blood flows were not associated with changes in microvascular perfusion.     

Evaluation of transcutaneous Doppler ultrasonography for the measurement of blood flow in the femoral artery of pigs

OBJECTIVE: To compare measurements of blood flow in the common femoral artery obtained by duplex Doppler ultrasonography (DDU) and a reference ultrasonic transit-time flow (TTF) method and to examine the impact of Doppler spectral waveform measurement techniques on volumetric estimates. ANIMALS: 5 healthy female pigs. PROCEDURES: Femoral arterial blood flow was measured simultaneously in anesthetized pigs by use of a TTF probe (left femoral artery) and transcutaneous DDU (right femoral artery). A range of flow states was induced pharmacologically by using xylazine, bradykinin, dobutamine, and isoflurane. Volumetric blood flow was calculated from DDU waveforms, using the product of the flow velocity integral (FVI), the cross-sectional vessel area, and heart rate. Three calculations of FVI were obtained by manually tracing the Doppler spectral envelopes at the outer envelope, the modal, and the inner envelope of the spectral dispersion pattern. Data analysis included calculation of Pearson correlation coefficients and Bland-Altman limits of agreement. RESULTS: Blood flow measured by DDU was more closely correlated with TTF measurements when the modal or inner envelope tracing method was used (r, 0.76 and 0.78; limits of agreement, -100 to 54.2 and -48.5 to 770 mL/min, respectively). Limits of agreement for the outer envelope tracing method were -238.5 to 64 mL/min. CONCLUSIONS AND CLINICAL RELEVANCE: Transcutaneous DDU is a reliable noninvasive technique for measuring blood flow in the femoral artery of pigs over a range of flow states. Tracing the inner envelope of the Doppler spectral dispersion pattern provided the best estimate of blood flow in this study.     

Evaluation of a new oscillometric blood pressure monitor in isoflurane-anesthetized dogs

Objective This study was conducted to evaluate the performance of a new veterinary oscillometric noninvasive blood pressure (NIBP) monitor in anesthetized dogs. Study design Assessment was made to determine how closely indirect measurements were associated with direct measurements, and if there were statistically significant differences between the measurements by site. Animals Six mongrel dogs weighing 27.8 ± 2.9 kg. Methods Dogs were anesthetized with thiopental and maintained with isoflurane, which was delivered with controlled ventilation. Direct pressure measurements were obtained via a percutaneously placed arterial catheter. A range of systolic arterial pressures (SAP) were achieved by changing the isoflurane concentrations. Sites of cuff placement for indirect measurements were identified as metacarpus, metatarsus, and anterior tibial. Results At pressures below 80 mm Hg, indirect systolic measurements averaged 4 ± 3 mm Hg, higher than the direct values. At normal and high levels, indirect systolic measurements underestimated direct values by 18 ± 6 and 23 ± 6 mm Hg, respectively. Diastolic and mean pressure measurements followed the same trend, with indirect values being lower than the direct arterial pressures. Systolic, diastolic and mean arterial pressure measurements differed by cuff‐placement site. Conclusions When analyzed by site and level, indirect systolic and mean arterial blood pressures during hypotension were essentially the same as direct pressures. However, at pressures within the normal or high range, indirect measurements underestimated the direct pressures. Clinical relevance Noninvasive blood pressure measurements with a new oscillometric monitor provided an excellent means of detecting arterial hypotension in anesthetized dogs. The metatarsal site for cuff placement was slightly better than the metacarpal or anterior tibial site, considering that the regression line was closest to complete equality between the indirect and direct measurements for SAP.     

Indirect oscillometric and direct blood pressure measurements in anesthetized and conscious neonatal foals

Objective: To investigate the agreement between indirect oscillometric and direct blood pressure measurement in the equine neonate. Design: Prospective observational study. Setting: University Veterinary Teaching Hospital. Animals: Ten crossbred foals of 30–46 hours of age. Interventions: Six animals (Group 1) were anesthetized. Four animals (Group 2) were restrained on a mat. All animals were instrumented with a catheter in the greater metatarsal artery and an oscillometric blood pressure cuff over the coccygeal artery. Blood pressure was varied with dobutamine, phenylephrine, nitroprusside, and increased depth of anesthesia (Group 1) or dopamine (Group 2). Measurements and main results: Simultaneous direct and indirect blood pressure measurements were obtained from the greater metatarsal artery and the coccygeal artery, respectively. There was good agreement between the 2 methods for mean and diastolic blood pressures in both groups, but not for systolic pressure. The agreement was best in mean blood pressure of anesthetized foals (mean bias –1.07; limits of agreement – 9.39, 7.25 mmHg). Conclusions: Indirect oscillometry appears to be an acceptable method for measuring mean arterial blood pressure in both anesthetized and conscious neonatal foals, and may be a valid method of monitoring critically ill foals.     

Blood pressure assessment in healthy cats and cats with hypertensive retinopathy

OBJECTIVE: To determine whether there was an association between hypertensive retinopathy and high systolic, diastolic, and mean arterial blood pressures in cats. ANIMALS: 181 cats. PROCEDURE: Systolic, diastolic, and mean arterial blood pressures were measured by use of a noninvasive oscillometric technique. The range of blood pressure measurements in healthy cats from various age groups was determined. Associations among systolic, diastolic, and mean arterial blood pressure; hypertensive retinopathy; hyperthyroidism; left ventricular cardiac hypertrophy; chronic renal failure; and serum biochemical abnormalities were determined. RESULTS: All blood pressure measurements increased with age in healthy cats. The frequency of hypertensive retinopathy also increased with age and with blood pressure, and hypertensive retinopathy was particularly found in cats with systolic blood pressures > 168 mm Hg. There was an increased risk for hypertensive retinopathy in cats that were female, > 10 years old, and neutered. The risk of chronic renal failure also increased as blood pressure, particularly systolic blood pressure, increased. CONCLUSIONS AND CLINICAL RELEVANCE: Hypertensive retinopathy was common in cats > or = 10 years of age and was associated with systolic blood pressures > 168 mm Hg when measured by the noninvasive oscillometric technique.     

Accuracy of indirect measurement of blood pressure in neonatal foals

The objectives of this study were to assess, in anesthetized neonatal foals, the accuracy of 2 automated indirect oscillometric monitors for measurement of mean arterial pressure (MAP), to determine the optimal site of cuff placement for MAP monitoring, and to determine the relationship between arterial blood pressure and cardiac output. Ten neonatal foals were anesthetized and instrumented with a catheter in the metatarsal artery for direct MAP monitoring and measurement of cardiac output by lithium dilution. Concurrent MAP measurements were obtained with Cardell and Dinamap oscillometric monitors with cuffs placed at 3 different sites (coccygeal, metatarsal, and median arteries). Blood pressure was manipulated by varying the depth of anesthesia and by administration of dobutamine or phenylephrine. A statistically significant (P = .025) interaction was found between the type of monitor and cuff placement site. With the Cardell monitor, placement of the cuff over the coccygeal artery resulted in a significantly lower bias than placement over the median or dorsal metatarsal artery (P < .0001 and P = .0149, respectively). No significant difference in bias was found with cuff placement site when using the Dinamap monitor. The correlation coefficient (r) between MAP and cardiac output was 0.47. Indirect oscillometry with a cuff placed over the coccygeal artery or dorsal metatarsal artery is an acceptable method for measuring MAP in foals. Blood pressure does not correlate well with cardiac output in anesthetized foals.     

MEASUREMENTS OF HINDLIMB BLOOD FLOW RECORDED USING DOPPLER ULTRASOUND DURING ADMINISTRATION OF VASOACTIVE AGENTS IN HALOTHANE-ANESTHETIZED HORSES

The purpose of the study was to determine the ability of Doppler ultrasound to detect changes in femoral blood flow during pharmacologic manipulation of arterial blood pressure. Doppler ultrasonography was performed in the femoral vessels of six halothane-anesthetized horses before and during administration of phenylephrine HCI and sodium nitroprusside. The time-averaged mean velocity and volumetric flow were calculated. The contour of the velocity waveform was assessed, and the early diastolic deceleration slope (EDDS) and pulsatility index (PI) were calculated. Administration of phenylephrine HCI resulted in increased mean aortic blood pressure (MABP) by 40% (29.3-53.0%). This caused significant decrease in cardiac output (26.8 to 13.5 l/min), femoral arterial velocity (left artery 7.20 to 4.00 cm/s; right artery 5.01 to 3.39 cm/s) and volumetric flow (left artery 556 to 221 ml/min; right artery 397 to 193 ml/min) in the femoral vessels and significant increase in systemic vascular resistance (163 to 433 dyn-s/cm5), EDDS (1a: 285 to 468: ra: 250 to 481) and PI (1a: 9.38 to 20.4; ra 17.1 to 29.1). Administration of sodium nitroprusside resulted in a decreased MABP of 27.2% (22.5-33%). This increased cardiac output (20.8 to 32.4 L/min), however, no significant changes were observed in femoral blood flow. Despite obvious changes in the waveform contour, no significant change occurred in EDDS or PI. These results suggest that Doppler ultrasound may be useful for measuring femoral blood flow in anesthetized horses. However, waveform analysis appears to be limited when multiple changes occur in central and peripheral haemodynamics.     

Doppler blood pressure measurement in pigs during anaesthesia

To determine the accuracy of Doppler blood pressure measurement in anaesthetised pigs eight large white pigs (Sus scrofa) were anaesthetised with zolazepam and tiletamine as Zoletil 100 (4 mg/kg) and xylazine (2 mg/kg) by intramuscular injection followed by isoflurane in 100% oxygen. Blood pressure measurements were recorded using a Doppler probe on the radial artery and a catheter in the femoral artery connected to a transducer. The sample mean of the Doppler measurements were compared with the sample mean of the invasive systolic arterial blood pressure while accounting for the heart rate, end-tidal CO₂ and temperature. The predicted error of the Doppler was greatest when pigs were hypotensive and normothermic: 11 mmHg (CI: 6–15). Doppler measurements should be interpreted with caution in anaesthetised pigs that are hypotensive and normothermic.     

Evaluation of indirect blood pressure monitoring in awake and anesthetized red-tailed hawks (Buteo jamaicensis): effects of cuff size, cuff placement, and monitoring equipment

ObjectiveTo compare Doppler and oscillometric methods of indirect arterial blood pressure (IBP) with direct arterial measurements in anesthetized and awake red-tailed hawks.Study designProspective, randomized, blinded study.AnimalsSix, sex unknown, adult red-tailed hawks.MethodsBirds were anesthetized and IBP measurements were obtained by oscillometry (IBP-O) and Doppler (IBP-D) on the pectoral and pelvic limbs using three cuffs of different width based on limb circumference: cuff 1 (20–30% of circumference), cuff 2 (30–40%), and cuff 3 (40–50%). Direct arterial pressure measurements were obtained from the contralateral superficial ulnar artery. Indirect blood pressure measurements were compared to direct systolic arterial pressure (SAP) and mean arterial pressure (MAP) during normotension and induced states of hypotension and hypertension. Measurements were also obtained in awake, restrained birds. Three-way anova, linear regression and Bland–Altman analyses were used to evaluate the IBP-D data. Results are reported as mean bias (95% confidence intervals).ResultsThe IBP-O monitor reported errors during 54% of the measurements. Indirect blood pressure Doppler measurements were most accurate with cuff 3 and were comparable to MAP with a bias of 2 (?9, 13 mmHg). However, this cuff consistently underestimated SAP with a bias of 33 (19, 48 mmHg). Variability in the readings within and among birds was high. There was no significant difference between sites of cuff placement. Awake birds had SAP, MAP and diastolic arterial pressure that were 56, 43, and 38 mmHg higher than anesthetized birds.Conclusions and clinical relevanceIndirect blood pressure (oscillometric) measurements were unreliable in red-tailed hawks. Indirect blood pressure (Doppler) measurements were closer to MAP measurements than SAP measurements. There was slightly better agreement with the use of cuff 3 on either the pectoral or pelvic limbs. Awake, restrained birds have significantly higher arterial pressures than those under sevoflurane anesthesia.     

Systolic blood pressure in cats with diabetes mellitus

OBJECTIVE: To determine the prevalence of systemic hypertension in cats with diabetes mellitus and establish ranges for echocardiographic variables in diabetic cats. DESIGN: Prospective study. ANIMALS: 14 cats with diabetes mellitus and 19 healthy control cats. PROCEDURE: Systolic blood pressure was measured indirectly with a noninvasive Doppler technique. Ophthalmic and echocardiographic examinations were performed, and urine protein concentration was measured. Cats were considered to have hypertension if they had systolic blood pressure > 180 mm Hg and at least 1 other clinical abnormality typically associated with hypertension (eg, hypertensive retinopathy, left ventricular hypertrophy, or proteinuria). RESULTS: None of the diabetic or control cats had systolic blood pressure > 180 mm Hg. One diabetic cat had left ventricular hypertrophy, but systolic blood pressure was 174 mm Hg. None of the cats had evidence of hypertensive retinopathy or proteinuria. Mean values for echocardiographic variables for the diabetic cats were not significantly different from published values for healthy cats. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that hypertension does not occur or occurs in only a small percentage of cats with diabetes mellitus.     

Duplex Doppler Estimation of Pourcelot Resistive Index in Arcuate Arteries of Sedated Normal Cats

Renal failure is an important cause of morbidity and mortality in feline patients. In human patients, intrarenal blood flow values obtained with duplex Doppler ultrasonography have been used to aid in the diagnosis and prognosis of renal failure. The purpose of this report is to present values for resistance to intrarenal blood flow in normal cats, derived by duplex Doppler ultrasonography. Ten mature clinically healthy conditioned domestic shorthaired cats were screened for normal renal anatomy and function by CBC, serum biochemical profile, urinalysis, urine protein/creatinine ratio, endogenous creatinine clearance, and renal B-mode ultrasonography; and for normal systemic blood pressure with Doppler pressure cuff measurement. Subsequently, the cats were sedated with ketamine hydrochloride, and values for mean intrarenal (arcuate artery) resistance to blood flow were determined by duplex Doppler ultrasonography, and expressed as the Pourcelot resistive index, a ratio of systolic to diastolic flow commonly used in duplex Doppler sonography in human patients. After duplex Doppler sonographic examination, histological normalcy of the kidneys was verified by evaluation of ultrasound-guided percutaneous renal biopsy. Based on the obtained resistive indices, 95% confidence intervals for normal values were calculated as follows: left kidney, 0.52 to 0.60; right kidney, 0.55 to 0.63. No statistically significant difference was noted between the values obtained for the right versus the left kidney. J Vet Intern Med 1996;10:28–33. Copyright © 1996 by the American College of Veterinary Internal Medicine .     

Spectral Doppler ultrasound in the major arteries of normal conscious immature micropigs

Spectral waveform analysis of blood flow velocity in the major arteries of six healthy, conscious immature micropigs was determined using Doppler ultrasonography. Doppler spectral tracings were recorded from the external iliac artery, femoral artery, and renal arcuate artery. Tracings were also taken from three parts of the common carotid artery and two parts of the abdominal aorta. Spectral Doppler parameters included peak systolic velocity, early diastolic velocity, peak systolic velocity-to-end diastolic velocity ratio, resistive index, and pulsatility index. In addition, the diameter of major arteries and indirect blood pressure were measured. These results from spectral Doppler analysis in major arteries may be useful as reference ranges in the future studies of vascular hemodynamics in immature micropigs.