Comparison of Doppler ultrasonic sphygmomanometry, oscillometry and high-definition oscillometry for non-invasive blood pressure measurement in conscious cats.

OBJECTIVES: Systemic arterial hypertension is a common occurrence and can have serious adverse consequences in cats. Therefore, measuring blood pressure is very important. There are many indirect blood pressure measurement devices available. This study compared Doppler, oscillometric (petMAP Graphic II, SunTech Vet20, the Cardell Insight-X0000) and high-definition oscillometry devices for the non-invasive measurement of blood pressure in conscious cats. METHODS: In this prospective study, blood pressure was measured in 32 cats using the different devices according to the recommendations of the American College of Veterinary Internal Medicine Consensus Statement. Blood pressures (systolic blood pressure [SBP], diastolic blood pressure [DBP], mean arterial pressure [MAP]), time to complete measurements, number of attempts needed, coefficient of variation (CV) between the blood pressure measurements of the different devices, ease of completing measurements and apparent stress level of the cat were assessed. RESULTS: There was a significant difference between devices in the time taken to obtain blood pressure readings and the number of attempts necessary to obtain six reliable measurements. The CV of the Doppler device was significantly smaller than that of the rest of the devices, but there were no other differences between the devices. The mean SBP, DBP and MAP measured by the petMAP device were significantly higher than the measurements from the other devices. The perceived ease of measurement was not significantly different between the various machines. The perceived level of stress of measurement with the Doppler device was significantly higher compared with the other devices but did not lead to an increased SBP. CONCLUSIONS AND RELEVANCE: Using a Doppler device to measure blood pressure in conscious cats is fast, relatively easy and gives reliable results. A disadvantage is that the Doppler device can only measure SBP, while oscillometric devices also provide DBP and MAP. However, in veterinary medicine, systolic hypertension is considered the most relevant.

Systolic blood pressure measurements with Doppler ultrasonic flow detector and high-definition oscillometry are comparable on population level but show large intra-individual differences in apparently healthy elderly dogs.

OBJECTIVE: Agreement of systolic blood pressure measurements (SBP) between noninvasive blood pressure devices in conscious dogs is poorly studied. Situational hypertension is expected in clinics, but studies are lacking. This study aimed to compare SBP measurements obtained with Doppler ultrasonic flow detector (Doppler) versus high-definition oscillometry (HDO) in clinics and at home and to estimate the prevalence of situational hypertension in conscious, apparently healthy elderly dogs. ANIMALS: 122 apparently healthy elderly or geriatric dogs were prospectively recruited. PROCEDURES: Systolic blood pressure was obtained consecutively with Doppler and HDO techniques in a randomized order per dog, following a standardized protocol. An at-home measurement was advised for in-clinic hypertensive dogs (SBP ≥ 160 mmHg), also using both devices. RESULTS: Dual measurements were available in 102 dogs. Median SBP was 147.3 mmHg (range, 105 to 239 mmHg) for Doppler and 152.3 mmHg (range, 113 to 221 mmHg) for HDO. Forty-six percent (56/122) were hypertensive, of which 9% (11/122) were hypertensive with both methods. No significant difference was found between the 2 devices in the global study population or within the group of hypertensive dogs. Repeated at-home measurements were performed in 20/56 (35.7%) hypertensive dogs, resulting in a 10 and 26 mmHg lower median SBP value for Doppler and HDO, respectively (P > .05). In-clinic situational hypertension was presumed in 8/20 (40%) dogs. CLINICAL RELEVANCE: The choice of the noninvasive blood pressure device did not significantly impact SBP results, but large interindividual differences in SBP between techniques occurred. Situational hypertension was frequently observed in clinic.

EVALUATION OF AGREEMENT BETWEEN OSCILLOMETRIC AND DIRECT BLOOD PRESSURE MEASUREMENTS IN ANESTHETIZED TIGERS (PANTHERA TIGRIS).

Noninvasive blood pressure measurement is commonly performed with oscillometry; however, this technique provides clinically helpful information only if it is representative of the gold standard. Agreement between direct and oscillometric blood pressure measurements were performed in 14 anesthetized, captive tigers (Panthera tigris). A cuff, placed around the tail base and connected to a multiparameter monitor, was used to measure arterial blood pressure oscillometrically and provided systolic, mean, and diastolic pressures. At the same time, direct blood pressures were obtained from a dorsal pedal arterial catheter, and the oscillometric and direct readings were considered paired data points. Agreement between the two methods was evaluated by Bland-Altman plots. All animals completed the study and provided 196 paired data points. The bias (mm Hg) for systolic, mean, and diastolic arterial pressures was -3.7, -0.8, and -1.6, respectively. Limits of agreement (mm Hg) for systolic, mean, and diastolic arterial pressures were -31 to 24, -29 to 27, and -29 to 26, respectively. Oscillometry provided an acceptable amount of readings within 10 and 20 mm Hg of the gold standard. The oscillometric technique provided reasonable agreement with direct measurements. Therefore, in the conditions used in this study, oscillometric blood pressure measured via the ventral coccygeal artery provided reasonable estimates of invasive blood pressure in anesthetized tigers.

Agreement of high-definition oscillometry at two cuff locations with invasively measured arterial blood pressures in anaesthetised cheetahs.

OBJECTIVES: To evaluate the agreement between high-definition oscillometry (HDO) used on the metatarsus or tail base with invasive arterial blood pressures measured in the dorsal pedal artery in anaesthetised cheetahs. STUDY DESIGN: Prospective clinical study. ANIMALS: A group of 13 captive adult cheetahs. METHODS: Cheetahs were immobilised with medetomidine (32-45 µg kg-1) and tiletamine/zolazepam (0.93-1.39 mg kg-1) administered intramuscularly, and anaesthesia was maintained with either isoflurane in oxygen or continuous propofol infusion. Invasive blood pressure was measured via a 20 gauge intra-arterial catheter in the dorsal pedal artery in the metatarsus and used as a reference method for pressures simultaneously estimated using HDO on the contralateral metatarsus and tail base. Bland-Altman plots (for repeated measurements) and criteria defined by the American College of Veterinary Internal Medicine (ACVIM) were used to compare agreement according to the anatomical location of the cuff, the anaesthetic maintenance agent and magnitude of the blood pressure. RESULTS: A total of 147 paired measurements were obtained with HDO on the metatarsus and 135 on the tail. Agreement with invasive pressures was better when HDO was used on the tail (rather than on the metatarsus) with all ACVIM criteria being met. Mean bias (a positive bias meaning that HDO overestimated the invasively measured pressures) ± standard deviation of differences for systolic, diastolic and mean arterial pressures were -7.0 ± 13.9, 4.2 ±12.1 and 4.6 ±11.2 mmHg, respectively, for HDO on the tail, and -11.9 ±15.1, 2.8 ±16.5 and 2.1 ±13.2 mmHg, respectively, for HDO on the metatarsus. Agreement was better during isoflurane anaesthesia than propofol, and at lower blood pressures than at higher. CONCLUSIONS AND CLINICAL RELEVANCE: When used on the tail base of anaesthetised cheetahs, HDO met the ACVIM validation criteria for a noninvasive device, as compared to invasively measured pressures in the dorsal pedal artery.

Comparison between the Parks Medical Doppler and the Mano Médical Vet BP Doppler for recording indirect systemic blood pressure in conscious dogs.

Background: The acquisition of systemic blood pressure (SBP) provides valuable information regarding cardiovascular function and tissue perfusion in human and veterinary species. Aim: To evaluate the agreement between Parks Medical Doppler (PMD) and Mano Médical Vet BP (MMVBP) Doppler for assessing SBP in conscious dogs. Methods: 40 client-owned dogs were prospectively enrolled; SBP measurements were acquired by a single operator using the PMD and then the MMVBP. The mean of five consecutive measurements for each device was classified according to target organ damage (TOD) risk scores (1: <140 mmHg; 2: 140-160 mmHg; 3: 160-180 mmHg; 4: ≥ 180 mmHg). Results: Total mean SBP for the devices was not statistically different (p = 0.77). However, the Bland-Altman analysis revealed wide limits of agreement (LoA), with MMVBP slightly underestimating SBP compared to PMD (bias = -0.6 mmHg, 95% LoA: -26.3 to 25.09). Both devices correlated well ( r = 0.8269; p < 0.0001) and had identically acceptable intra-observer repeatability (coefficients of variation = 4.09% for MMVBP and 3.86% for PMD). Four dogs (10%) had a TOD score of 3 by one device but scored <3 with the other. Conclusion: A good agreement and correlation was observed between the PMD and the MMVBP, suggesting that both devices can be used interchangeably for assessment of SBP in conscious dogs. The wide LoA observed between both devices was most likely associated with intraindividual variability in SBP over time.

Use of a human wrist blood pressure monitor for arterial blood pressure measurements in normotensive conscious dogs in comparison to veterinary high-definition oscillometry.

BACKGROUND: The gold standard in canine blood pressure (BP) measurement is the invasive method; however, non-invasive blood pressure measurement techniques (NIBP) are more commonly used. The lack of small, lightweight, cheap, fast and portable NIBP still remains a point to improve in the emergency setting. KEY FINDINGS: A human wrist blood pressure (WBP) device was evaluated in comparison with the veterinary high-definition oscillometry (HDO) in conscious normotensive dogs. Systolic and diastolic BPs were evaluated in two groups of dogs. The bias, the limits of agreement and correlation between variables were calculated. Twenty-five and 36 dogs were, respectively, included in Study No. 1 (dogs weighting ≥10 kg) and 2 (dogs weighting ≥20 kg). In both studies, correlation between the two devices was moderate. A better agreement was displayed for diastolic pressure and poor precision for both systolic and diastolic pressures measurements (as determined by wide limits of agreement). The WBP method underestimated both the systolic and diastolic BP with respect to the HDO method. The inclusion of bigger dogs (Study No. 2) with limb circumference more like to human limb dimension did not improve the agreement between considered methods. SIGNIFICANCE: The human WBP monitor considered is not suitable to replace the commonly used veterinary HDO for in-clinic BP monitoring in normotensive conscious dogs.

Agreement of caudal aortic arterial blood pressure with oscillometry using two cuff widths placed on the thoracic or pelvic limbs of sevoflurane-anesthetized rabbits.

OBJECTIVE: To evaluate agreement with central systemic arterial pressure of an oscillometer and two cuff widths placed on the thoracic or pelvic limbs. STUDY DESIGN: Prospective experimental study. ANIMALS: A group of nine New Zealand White rabbits weighing 3.5 ± 0.3 kg. METHODS: Rabbits were sedated with dexmedetomidine and midazolam, then anesthetized with ketamine and sevoflurane. The femoral artery was surgically exposed and a 20 gauge, 5 cm catheter inserted to measure systolic (SAP), mean (MAP) and diastolic (DAP) blood pressure at the iliac artery and caudal aorta junction. Adjustments of vaporizer dial and dobutamine infusion provided a range of invasive blood pressure (IBP). Two measurements of IBP were recorded during the oscillometer cycling phase, and the mean value was used in analyses. Oscillometer cuffs of bladder width 2.0 cm (S1) and 2.5 cm (S2) were placed proximal to the carpus and tarsus. Cuff width to circumference ratio was calculated. Oscillometer SAP, MAP and DAP were paired with corresponding IBP values. Agreement was assessed using linear mixed models (p < 0.05). RESULTS: Cuff ratios for both limbs were 41% (S1 cuff) and 50% (S2 cuff) and 122-139 paired observations were obtained. There was significant limb × cuff interaction with SAP and MAP. The oscillometer overestimated SAP and MAP on the pelvic limb and underestimated SAP and MAP on the thoracic limb. For SAP, the oscillometer overestimated by constant bias (-19 ± 2 mmHg) and proportional bias (0.28 ± 0.02 mmHg per 1 mmHg increase). For MAP, the oscillometer underestimated by constant bias (4 ± 2 mmHg) and was worse with S2 on the thoracic limb. Overestimation was similar between cuffs on the pelvic limb. For DAP, the oscillometer underestimated by constant bias (15 ± 2 mmHg). CONCLUSIONS AND CLINICAL RELEVANCE: Cuff S1 on the thoracic limb provided best estimation of MAP.

Validation of oscillometric blood pressure measurement using a Datex S/5 Compact multiparameter monitor in anaesthetized adult dogs.

OBJECTIVE: To compare noninvasive (NIBP) with invasive blood pressure (IBP) measurements from a Datex S/5 Compact monitor in anaesthetized adult dogs, and to evaluate it according to the American College of Veterinary Internal Medicine (ACVIM) and the Association for the Advancement of Medical Instrumentation (AAMI) criteria. STUDY DESIGN: Prospective clinical study. ANIMALS: A group of 34 client-owned adult dogs. METHODS: Dogs were anaesthetized for different surgical procedures using different anaesthetic protocols. IBP was measured using a catheter placed in a dorsal pedal artery. A blood pressure cuff was placed over the contralateral dorsal pedal artery for NIBP measurement. Data were recorded using the Datex iCollect program, and paired readings were matched every 3 minutes for 60 minutes. Bland-Altman and error grid analyses were used to estimate the agreement between IBP and NIBP measurements, and its clinical significance, respectively. Data were reported as mean bias [lower, upper limits of agreement (LoA)]. RESULTS: The Datex S/5 monitor conformed to most ACVIM criteria. The correlation coefficient was less than 0.9 for systolic, diastolic, and mean arterial pressures (MAP). The best agreement between the noninvasive and invasive methods was observed for MAP, with LoA (-17 to 13 mmHg) and higher percentage of NIBP readings within 5 (55.6%), 10 (81.7%) and 20 (98.6%) mmHg of the IBP values. The Datex S/5 NIBP technology did not meet the AAMI validation criteria and less than 95% of the paired measurements were found within the green zone of the error grid analysis. CONCLUSIONS AND CLINICAL RELEVANCE: The Datex S/5 monitor conformed to most ACVIM criteria but not with the more rigorous AAMI standards. Despite good agreement between IBP and NIBP for MAP measurements, care must be taken when using this device to guide therapeutic interventions of blood pressure in anaesthetized healthy adult dogs.

Evaluation of the tongue for oscillometric measurement of arterial pressure in anesthetized Beagle dogs.

OBJECTIVE: To evaluate the agreement between oscillometric blood pressure (OBP) measured from the tongue and invasive blood pressure (IBP), and to compare OBPs measured from the tongue with OBPs measured from the pelvic limb and tail. STUDY DESIGN: Prospective experimental study. ANIMALS: A total of eight adult Beagle dogs weighing 11.1 ± 1.2 kg. METHODS: Animals were premedicated with intravenous (IV) acepromazine (0.005 mg kg-1). Anesthesia was induced with alfaxalone (3 mg kg-1) IV and maintained with isoflurane. The dorsal pedal artery was catheterized for IBP measurements. Systolic (SAP), diastolic (DAP) and mean (MAP) arterial pressure were simultaneously measured from the tongue, pelvic limb and tail. Based on invasive SAP, hypertension (>140 mmHg), normotension (90-140 mmHg) and hypotension (<90 mmHg) were induced by controlling end-tidal isoflurane concentrations and/or dobutamine/dopamine administration. Agreement between paired IBP and OBP measurements was analyzed with reference standards for noninvasive blood pressure devices used in small animals and humans. RESULTS: Regardless of cuff placement, the mean bias ± standard deviation between IBP and OBP met veterinary (≤10 ± 15 mmHg) and human (<5 ± 8 mmHg) standards for MAP and DAP. SAP measurements provided by the OBP device showed unacceptable agreement with IBP, and the bias between methods increased at higher blood pressures, regardless of cuff site. During hypotension, tongue OBP showed the largest percentage of absolute difference <10 mmHg in relation to IBP for SAP (90%), MAP (97%), and DAP (93%), compared with pelvic limb (60%, 97% and 82%, respectively) and tail OBP (54%, 92% and 77%, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: The tongue is a clinically useful site for measuring OBP in anesthetized Beagle dogs, providing reliable estimates of MAP and DAP. The tongue could replace other cuff placement sites and may be a relatively suitable site for assessing hypotension.

Agreement between oscillometric and direct blood pressure measurements in anesthetized captive chimpanzees (Pan troglodytes).

OBJECTIVE: To evaluate the level of agreement (LOA) between direct and oscillometric blood pressure (BP) measurements and the ability of oscillometric measurements to accurately detect hypotension in anesthetized chimpanzees (Pan troglodytes). ANIMALS: 8 captive, adult chimpanzees. PROCEDURES: During prescheduled annual examinations, each chimpanzee underwent general anesthesia and patient monitoring for their examination, echocardiography for a concurrent study, and measurement of direct BP with the use of tibial artery catheterization and oscillometry with the use of a cuff placed around a brachium and a cuff placed around the second digit of the contralateral forelimb for the present study. Bland-Altman plots were generated to compare results for direct and oscillometric BP measurements. Mean bias and 95% LOAs were calculated for oscillometric measurements of systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP) for each cuff site. Sensitivity and specificity in detecting hypotension were also determined for each cuff site. RESULTS: There were 74 paired direct and brachial oscillometric measurements of each, SAP, MAP, and DAP and 66 paired direct and digit oscillometric measurements of each, SAP, MAP, and DAP. Only brachial oscillometric measurements of MAP had adequate sensitivity (78%) and specificity (95%) to accurately detect hypotension, and this technique also had the least mean bias (0.8 mm Hg; 95% LOA, -29 to 31 mm Hg). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that brachial oscillometric measurement of MAP provided reasonable agreement with tibial arterial direct MAP measurement and performed well in diagnosing hypotension in anesthetized chimpanzees.

Evaluation of noninvasive blood pressure in anesthetized horses: Bias, limits of agreement, and comparative detection of a predetermined mean blood pressure warranting treatment.

Oscillometric blood pressure monitoring may be a practical tool for short procedures or those performed outside of the operating room. Oscillometric and direct blood pressure values in 30 juvenile and adult horses in a clinical setting using mixed effect models were compared. The limits of agreement and percentage errors were also calculated. We evaluated the sensitivity and false positive rate for the oscillometric method to trigger an intervention for treating blood pressure [direct mean arterial pressure (MAP) < 70 mmHg]. Oscillometric MAP and diastolic arterial pressure (DAP) differed from direct values (P < 0.001); systolic arterial pressure (SAP) did not (P = 0.08). Wide limits of agreement were observed. Percentage errors were smaller for SAP (39%) than for MAP and DAP (48% and 72%). The oscillometric monitor indicated there was a requirement for blood pressure treatment with a true positive rate of 82%, consequently, it failed 18% of the times. The false positive rate (unnecessary treatment) was 55%.

Évaluation non invasive de la pression artérielle chez des chevaux anesthésiés: biais, limites d'accord et détection comparative d'une pression artérielle moyenne prédéterminée justifiant un traitement. La surveillance oscillométrique de la pression artérielle peut être un outil pratique pour les procédures courtes ou celles effectuées hors de la salle d'opération. Les valeurs oscillométriques et directes de la pression artérielle chez 30 chevaux juvéniles et adultes en milieu clinique ont été comparées à l'aide de modèles à effets mixtes. Les limites d'accord et les pourcentages d'erreurs furent également calculés. Nous avons évalué la sensibilité et le taux de faux positifs de la méthode oscillométrique pour déclencher une intervention pour le traitement de la pression artérielle [pression artérielle moyenne directe (PAM) < 70 mmHg]. La PAM oscillométrique et la pression artérielle diastolique (PAD) différaient des valeurs directes (P < 0,001); mais pas la pression artérielle systolique (PAS) (P = 0,08). De larges limites d'accord ont été observées. Les pourcentages d'erreurs étaient plus faibles pour PAS (39 %) que pour PAM et PAD (48 % et 72 %). Le moniteur oscillométrique a indiqué qu'il y avait une exigence pour un traitement de la pression artérielle avec un taux de vrais positifs de 82 %, par conséquent, il a échoué 18 % des fois. Le taux de faux positifs (traitement inutile) était de 55 %.(Traduit par Dr Serge Messier).

Influence of clinical setting and cat characteristics on indirectly measured blood pressure and pulse rate in healthy Birman, Norwegian Forest, and Domestic Shorthair cats.

BACKGROUND: Measured indirect blood pressure (BP) results in cats in a clinical environment might be affected by stress and characteristics of the cats. HYPOTHESIS: To investigate the influence of clinical setting, cat characteristics, and life situation on BP and pulse rate (PR) in healthy cats. ANIMALS: Ninety-four healthy Domestic Shorthair, Birman and Norwegian Forest cats. METHODS: Blood pressure measured by high-definition oscillometry in 3 settings: cat placed in its own carrier with veterinarian present; cat placed in carrier with owner alone present; and cat placed on table with veterinarian present. Statistical analyses were performed using mixed linear models. RESULTS: Systolic BP (SBP) did not differ among settings. Higher mean arterial pressure (MAP), diastolic BP (DBP), and PR were found when measurements were performed with cat placed on table, rather than in carrier. Coefficients of variation (CVs) higher for SBP, MAP, DBP, and PR when measured with cat placed on table than in carrier. Birman cats had lower BP than other breeds. Systolic BP, MAP, DBP, and PR increased with age. Cats allowed outdoors had lower PR than cats living strictly indoors. CONCLUSION AND CLINICAL IMPORTANCE: No difference in SBP was found among settings, but measuring BP with the cat placed on the examination table gave higher MAP, DBP, PR, and CV than measuring BP with the cat in its carrier. Breed affected BP, with lower BP in Birman cats than other breeds. Blood pressure increased with age. Pulse rate was lower in cats allowed outdoors than cats living strictly indoors.

Impact of equipment and handling on systolic blood pressure measurements in conscious dogs in an animal hospital environment.

BACKGROUND: Situational hypertension and differences between devices complicate interpretations of systolic blood pressure (SBP) measurements in dogs. HYPOTHESIS/OBJECTIVES: To evaluate if time point of in-clinic SBP measurement, type of oscillometric device, and operator affect SBP measurements in conscious dogs. ANIMALS: Sixty-seven privately owned dogs with or without chronic kidney disease, divided into 2 study samples (A and B). METHODS: Cross-sectional diagnostic study. In part A, SBP measurements in dogs were performed using 2 different devices (HDO and petMap) after acclimatization at 3 standardized time points during a clinical visit. In part B, SBP measurements (HDO) were performed in dogs by a trained final year veterinary student and by the owner alone, at the same occasion. RESULTS: For all dogs, there was no difference in mean SBP (mSBP) among the 3 time points for HDO (P = .12) or petMAP (P = .67). However, intraindividual mSBP differences of up to 60 mm Hg between time points were documented. Mean SBP obtained with petMAP was on average 14 (95% CI: 8-20) mm Hg higher than mSBP obtained with HDO, and this difference increased with increasing SBP. Mean SBP measurements obtained by the trained student were 7 (95% CI: 2-11) mm Hg higher than mSBP measurements obtained by the owner. CONCLUSIONS AND CLINICAL IMPORTANCE: According to the results of this study, time point of in-clinic SBP measurement in dogs is of minor importance, and instructing owners to perform measurements might reduce suspected situational hypertension. Differences in mSBP measured with HDO and petMAP underscore the need for validation of BP devices used clinically.

Evaluation of an oscillometric blood pressure monitor in anesthetized dogs: Agreement with direct measurements and ability to detect hypotension.

We evaluated the agreement between oscillometric and direct blood pressure monitors in anesthetized dogs and evaluated the ability of the oscillometric method to detect MAP <60 mmHg. Forty client-owned dogs, three months to 14 years old, 4.6-50.2 kg, under general anesthesia were studied. Systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures were measured directly via an arterial catheter and with an oscillometric cuff (Cardell Touch monitor). Paired values were compared with mixed effect models. Bias and limits of agreement (LOA) were calculated. The sensitivity and false negative rate to detect hypotension (invasive MAP <60 mmHg) using an oscillometric MAP <60 and < 70 mmHg were calculated. A receiver operating characteristics (ROC) curve was constructed and the area under the curve calculated. SAP and DAP differed between methods (both P < 0.001), but MAP did not (P = 0.5). Bland-Altman plots showed small biases but wide LOA for all variables. The sensitivity to detect hypotension was 40% with a false negative rate of 60% when using an oscillometric MAP <60 mmHg, and 68% and 32%, respectively, with a MAP <70 mmHg. The area under the ROC curve for MAP was 0.82. While the oscillometric MAP did not differ from invasive values, the device failed to recognize hypotensive events when 60 mmHg was used as the threshold to detect hypotension. Higher MAP values increased the ability to correctly recognize hypotension, but at the expense of a higher incidence of false positives.

Comparison of Doppler ultrasonic and oscillometric devices (with or without proprietary optimisations) for non-invasive blood pressure measurement in conscious cats.

OBJECTIVES: This study compared Doppler and oscillometric (PetMAP+) devices (with or without proprietary optimisations) for the non-invasive measurement of blood pressure in conscious cats. METHODS: Twenty-three cats were enrolled; however, five were excluded as fewer than five measurements were obtained for each assessment. All measurements were obtained according to American College of Veterinary Internal Medicine consensus guidelines. Oscillometric device modes A and B were operated according to the manufacturer's guidelines. Doppler and oscillometric devices were used alternately as the first device. RESULTS: Systolic arterial blood pressure (SAP) measurements were obtained by Doppler (SAPd) and oscillometry; the mean of each set of five values was used for statistical analysis. There was a significant difference between SAPd and SAP measurements in oscillometric modes A (P <0.001) and B (P <0.001). While both modes measured SAP higher than SAPd, B had a smaller bias (+15.72 mmHg) and narrower limits of agreement (LOA). There was also a significant difference between SAPd and mean arterial pressure (MAP) on oscillometric modes A (P = 0.002) and B (P <0.001). Both modes' MAP readings were lower than SAPd and oscillometric A MAP was closer to SAPd (-14.94 mmHg), with a smaller bias and narrower LOA. CONCLUSIONS AND RELEVANCE: The findings support that Doppler and oscillometric devices cannot be used interchangeably, with or without proprietary optimisations. Methodology should always be taken into account and reference intervals (RIs) need to be defined for the different methodologies. Until methodology-specific RIs are published, definitive diagnosis of hypertension and sub-staging of patients with kidney disease according to the International Renal Interest Society guidelines remains challenging.

Comparison of invasive and non-invasive blood pressure measurements in anesthetized female Dorset cross-bred lambs (Ovis aries).

The purpose of this study was to determine the level of agreement between invasive and noninvasive blood pressure measurements in anesthetized, non-surgically manipulated Dorset cross-bred lambs. Twelve healthy female Dorset cross-bred lambs, weighing 37.3 ± 7.4 kg (mean ± SD) underwent isoflurane anesthesia for simultaneous measurement of systolic arterial pressure (SAP), mean arterial pressure (MAP) and diastolic arterial pressure (DAP) from an invasive blood pressure source and a noninvasive oscillometric source (O-NIBP). The femoral artery was catheterized for invasive blood pressure measurements, while noninvasive blood pressure was measured from a cuff placed on the antebrachium. The Bland-Altman method was used to calculate agreement between SAP, MAP and DAP measurements. The bias ± SD between SAP, MAP and DAP measurements was 3.6 ± 12.0, 4.9 ± 9.1 mmHg and 4.1 ± 8.0, respectively. The 95% limits of agreement for SAP, MAP and DAP were - 19.9 to 27.1, -13.0 to 22.8 mmHg, and - 11.7 to 19.9, respectively. Overall, agreement was poor between femoral IBP and O-NIBP monitoring techniques in anesthetized Dorset cross-bred lambs, with O-NIBP underestimating the femoral IBP. Arterial blood pressure should be most accurately measured using an invasive blood pressure monitoring technique in lambs undergoing isoflurane anesthesia.

Review of non-invasive blood pressure measurement in animals: Part 2 - Evaluation of the performance of non-invasive devices.

Arterial blood pressure is a common parameter evaluated in conscious and anesthetized veterinary patients for a variety of reasons. Non-invasive blood pressure measurement techniques, such as Doppler ultrasound and oscillometry, are attractive in certain veterinary patients due to their availability and ease of use. The greatest limitation to non-invasive blood pressure monitoring can be its inaccuracy, particularly in hypotensive or hypertensive patients and in certain species. Part 1 of this 2-part review summarized the current techniques available to non-invasively measure arterial blood pressure in veterinary species and discussed validation of non-invasive devices. Part 2 summarizes the veterinary literature that evaluates the use of non-invasive blood pressure measurement techniques in conscious and anesthetized species and develops general conclusions for proper use and interpretation of non-invasive blood pressure devices.

Mesure de la pression sanguine de manière non-invasive chez les animaux. Partie 2 ­ Évaluation de la performance des équipements non-invasifs. La pression sanguine artérielle est un paramètre fréquemment évalué chez les patients vétérinaires conscients et anesthésiés pour une variété de raisons. Les techniques noninvasives de mesure de la pression sanguine, telles que les ultrasons Doppler et l'oscillométrie, sont intéressantes chez certains patients vétérinaires étant donné leur disponibilité et leur facilité d'utilisation. La principale limitation du suivi de la pression sanguine par des méthodes non-invasives peut être son imprécision, particulièrement chez des patients hypotensifs ou hypertensifs, et chez certaines espèces. La première partie de cette revue en deux parties résumait les techniques présentement disponibles pour mesurer de manière non-invasive la pression sanguine artérielle chez des espèces animales et discutait de la validation des équipements non-invasifs. La deuxième partie résume la littérature vétérinaire qui évalue l'utilisation de techniques non-invasives de mesure de la pression sanguine chez des espèces conscientes et anesthésiées et développe des conclusions générales pour l'utilisation et l'interprétation appropriées des équipements non-invasifs de mesure de la pression sanguine.(Traduit par Dr Serge Messier).

Non-invasive blood pressure measurement in animals: Part 1 - Techniques for measurement and validation of non-invasive devices.

Arterial blood pressure is a common parameter evaluated in conscious and anesthetized veterinary species. Non-invasive blood pressure measurement techniques, such as Doppler ultrasonic flow detector and oscillometry, are attractive in certain animals due to their availability and ease of use. The greatest limitation to non-invasive blood pressure monitoring can be its inaccuracy, particularly in hypotensive or hypertensive patients and in certain species. Part 1 of this 2-part review summarizes the current techniques available to non-invasively measure arterial blood pressure in animals and discusses validation of non-invasive devices. Part 2 summarizes the veterinary literature that evaluates the use of non-invasive blood pressure measurement techniques in conscious and anesthetized species and develops general conclusions for proper use and interpretation of data from non-invasive blood pressure devices.

Mesures de la pression sanguine chez les animaux de manière non-invasive: Partie 1 ­ Techniques pour mesurer et validation d'appareils non-invasifs. La pression sanguine artérielle est un paramètre fréquemment évalué chez les espèces animales conscientes et anesthésiées. Des techniques non-invasives de mesure de la pression sanguine, telles que le détecteur ultra-sonique de flot Doppler et l'oscillométrie, sont attirantes chez certains animaux étant donné leur disponibilité et facilité d'utilisation. La plus grande limitation au suivi non-invasif de la pression sanguine peut être son imprécision, particulièrement chez les patients hypotensifs ou hypertensifs et chez certaines espèces. La partie 1 de cette revue en deux parties résume les techniques présentement disponibles pour mesurer de manière non-invasive la pression sanguine artérielle chez des animaux et discute la validation d'équipements non-invasifs. La partie 2 résume la littérature vétérinaire qui évalue l'utilisation de techniques de mesure non-invasives de la pression sanguine chez des espèces conscientes et anesthésiées et développe des conclusions générales pour l'utilisation appropriée et l'interprétation des données obtenues d'équipements noninvasifs de mesure de la pression sanguine.(Traduit par Dr Serge Messier).

Assessment of a commercially available veterinary blood pressure device used on awake and anesthetized dogs.

OBJECTIVE: To compare results of a commercially available device for oscillometrically measured blood pressure (OBP) with invasively measured blood pressure (IBP) in awake and anesthetized dogs. ANIMALS: 19 adult dogs (mean ± SD body weight, 17.8 ± 7.5 kg). PROCEDURES: Blood pressures were measured in dogs while they were awake and anesthetized with isoflurane. The OBP was recorded on a thoracic limb, and IBP was simultaneously recorded from the median caudal artery. Agreement between OBP and IBP was evaluated with the Bland-Altman method. Guidelines of the American College of Veterinary Internal Medicine (ACVIM) were used for validation of the oscillometric device. RESULTS: In awake dogs, mean bias of the oscillometric device was -11.12 mm Hg (95% limits of agreement [LOA], -61.14 to 38.90 mm Hg) for systolic arterial blood pressure (SAP), 9.39 mm Hg (LOA, -28.26 to 47.04 mm Hg) for diastolic arterial blood pressure (DAP), and -0.85 mm Hg (LOA, -40.54 to 38.84 mm Hg) for mean arterial blood pressure (MAP). In anesthetized dogs, mean bias was -12.27 mm Hg (LOA, -47.36 to 22.82 mm Hg) for SAP, -3.92 mm Hg (LOA, -25.28 to 17.44 mm Hg) for DAP, and -7.89 mm Hg (LOA, -32.31 to 16.53 mm Hg) for MAP. The oscillometric device did not fulfill ACVIM guidelines for the validation of such devices. CONCLUSIONS AND CLINICAL RELEVANCE: Agreement between OBP and IBP results for awake and anesthetized dogs was poor. The oscillometric blood pressure device did not fulfill ACVIM guidelines for validation. Therefore, clinical use of this device cannot be recommended.

EVALUATION OF NONINVASIVE OSCILLOMETRIC BLOOD PRESSURE MONITORING IN ANESTHETIZED BENNETT'S WALLABIES (MACROPUS RUFOGRISEUS).

The objective of this study was to determine the accuracy of a noninvasive oscillometric method in relation to invasively measured blood pressure in anesthetized Bennett's wallabies (Macropus rufogriseus) and also to compare the accuracy of two commonly used oscillometric blood pressure monitors (manufactured by Cardell and Datascope). Eleven animals were anesthetized, and each animal was instrumented with an arterial catheter in the right medial metatarsal artery connected to a pressure transducer to obtain invasive measurements of systolic (SAP), diastolic (DAP), and mean (MAP) arterial blood pressure as well as a pressure waveform. A cuff connected to an oscillometric device was placed on the base of the tail for noninvasive measurements. Paired data from noninvasive and invasive blood pressure measurements (SAP, DAP, and MAP) were obtained every 5 min for 60 min. Bland-Altman plots were used to compare invasive and noninvasive measurements and calculate bias and 95% limits of agreement for SAP, DAP, and MAP. For both monitors, the bias of SAP, DAP, and MAP was significant, although the bias of the Cardell was consistently lower than that of the Datascope for all parameters. Limits of agreement were wide for all parameters. In conclusion, when using an oscillometric blood pressure monitor on anesthetized Bennett's wallabies, trends in blood pressure may be monitored, although all displayed readings may not represent the true blood pressure measurement. Indirect measurements of blood pressure made with the oscillometric device cannot substitute for direct measurements.