Radial vs coccygeal artery Doppler blood pressure measurement in conscious cats

Symmetric dimethylarginine correlates with the urea, creatinine, potassium, and clinical scores in feline urethral obstructions

BACKGROUND

A urethral obstruction (UO) is an emergency commonly observed in male cats, which can result in significant clinical and laboratory alterations, leading to complications and death.

OBJECTIVES

This study aimed to correlate symmetric dimethylarginine (SDMA) with the urea, creatinine, potassium, and bicarbonate levels in cats with UO. In addition, the correlation between clinical score and time of obstruction was evaluated.

METHODS

Thirty male cats were selected and allocated into a control group (CG, n = 13) and an obstruction group (OG, n = 17). The laboratory analyses were conducted before treatment (M0) and at different times after treatment (12 h [M12], 24 h [M24], and 48 h [M48]). Correlations were established between SDMA and creatinine, urea, bicarbonate, potassium, time of obstruction, and the clinical score.

RESULTS

A strong correlation (r > 0.6) was observed between SDMA and creatinine, urea, and potassium in the OG. Furthermore, there was substantial agreement (kappa value) between SDMA and creatinine at M24. A higher clinical score was associated with a longer time of obstruction. In the OG, at M48, the SDMA and creatinine levels were 50% and 41.2% higher, respectively.

CONCLUSIONS

A correlation was observed between SDMA and creatinine in obstructed cats, and significant agreement between these values was observed 24 h after the unblocking treatment. A correlation among SDMA, urea, and potassium was observed. Approximately 9% more cats continued to have elevated SDMA levels after 48 h of treatment compared to creatinine. This suggests a slightly lower sensitivity of the latter biomarker but does not exclude the possibility of congruent and normalized values after a longer evaluation period.

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.

Effect of audible static on blood pressure measurement by Doppler ultrasonic sphygmomanometry in cats

OBJECTIVES

The aim of the present study was to determine whether the use of headphones to eliminate audible static during Doppler ultrasonic sphygmomanometry affects blood pressure (BP) measurement in conscious young adult (aged 1-6 years) and mature adult/senior (aged ⩾7 years) cats.

METHODS

A randomized crossover study was conducted. Healthy client-owned cats (>1 year) were enrolled. Blood pressure measurements were obtained twice, 14 days apart, with or without the use of headphones worn by a veterinarian. A fear, anxiety and stress (FAS) score (0 = relaxed; 4 = severe signs) was recorded. A linear mixed-effects model was used to compare the effect of wearing headphones on BP measurement.

RESULTS

In total, 18 young adult and 14 mature adult and senior cats with a median age of 5 years (range 1-14 years) were enrolled. Of the cats, 47% (15/32) had an average BP measurement that was at least 10 mmHg higher when using headphones compared with when not using headphones, of which a majority (11/15, 73%) were young adult cats. The average BP measurement was not different when using headphones compared with when not using headphones (mean difference -7 mmHg; 95% confidence interval -14 to 0.6; P = 0.07). When compared within age groups, the average BP measurement taken when using headphones (125 ± 15 mmHg) was lower compared with the measurement taken when not using headphones (137 ± 17 mmHg) in young adult cats (P = 0.02).

CONCLUSIONS AND RELEVANCE

The reduction in the average BP measurement with the use of headphones suggests this method may be helpful in reducing situational hypertension, particularly in young adult cats. Our findings also highlight the importance of consistent use of headphones when comparing serial measurements in a cat.

Effect of gabapentin on ambulatory, direct, systemic arterial blood pressure in apparently healthy cats in the at-home and in-clinic environments

OBJECTIVES

Situational increases in blood pressure (BP) frequently confound the accurate diagnosis of pathological systemic hypertension in cats. The objective of this study was to investigate the effect of gabapentin on direct, ambulatory systolic arterial BP (SBP) in cats in at-home and in-clinic environments.

METHODS

Six adult purpose-bred cats with surgically implanted femoral artery telemetric BP-sensing catheters were administered 100 mg of gabapentin or a placebo orally in two randomized, masked, crossover study phases. In the first, direct BP was measured continuously in undisturbed cats for 24 h before (at-home baseline) and 4 h after administration of study drug. The mean SBP after administration of the drug was compared between treatments. In the second study period, cats were administered gabapentin or placebo 90 mins before transport to a clinic, where direct BP was measured continuously during a simulated veterinary visit that included an indirect BP measurement session. Changes in mean direct SBP relative to the 24-h at-home pre-treatment period were calculated for each of one waiting room and two examination-room periods, and compared between treatments. Concurrent in-clinic direct and indirect SBP measurements were compared within-cat. Data were compared using linear mixed models.

RESULTS

Direct SBP data from one cat were excluded due to implant failure. There were no differences in at-home or in-clinic SBP between treatment groups, with large inter-individual variability. Cats in both treatment groups experienced in-clinic increases in direct SBP relative to at-home baseline (range 11-50 and 10-52 mmHg in placebo- and gabapentin-treated cats, respectively). Across all visits, direct SBP was 15.6 mmHg higher than indirect SBP (P <0.001). No effects of treatment on difference between direct and indirect SBP were identified.

CONCLUSIONS AND RELEVANCE

Significant effects of gabapentin on direct SBP were not identified, though a type II error is possible. Situational increases cannot be excluded in gabapentin-treated cats with high SBP.

Cross-sectional survey of non-invasive indirect blood pressure measurement practices in cats by veterinarians

OBJECTIVES

This survey of small animal veterinarians endeavored to: (1) determine current methods of indirect blood pressure measurement; (2) detail techniques used to reduce situational hypertension; and (3) better understand the obstacles to performing blood pressure measurement in cats.

METHODS

An online survey was produced and circulated to members of the Veterinary Information Network. A total of 733 veterinarians who saw cats in their practice and had access to at least one indirect blood pressure device completed the entirety of the survey.

RESULTS

Ninety-six percent (703/733) of veterinarians who completed the survey reported measuring indirect blood pressure in cats in their practice, with veterinary technicians conducting most (600/703; 85.3%) of these measurements. Few veterinarians (30/733; 4.1%) did not measure blood pressure, with these veterinarians citing several obstacles including: difficulty interpreting results with the occurrence of fear, anxiety and stress in cats (20/30; 66.7%); difficulty performing measurements in cats (17/30; 56.7%); and technical staff being uncomfortable performing measurements (12/30; 40.0%). Most veterinarians (300/435; 69.0%) in this survey preferred an ultrasonic Doppler flow detector with sphygmomanometry, with many (272/300; 90.7%) perceiving that the results obtained with this device were more trustworthy compared with results obtained with oscillometry. Ninety percent (633/703) of veterinarians employed techniques to reduce situational hypertension in cats. Techniques perceived to be most helpful among veterinarians included: using a quiet location (454/633; 71.7%); minimizing restraint (316/633; 49.9%); performing blood pressure prior to other procedures (eg, phlebotomy, cystocentesis) (302/633; 47.7%); avoiding other animals (219/633; 34.6%); and allowing time for acclimation (167/633; 26.4%).

CONCLUSIONS AND RELEVANCE

This survey study of veterinarians helps clarify obstacles to routine blood pressure measurement in conscious cats. Veterinarians reported several strategies that they felt reduced situational hypertension in cats. The data inform modifications of techniques to increase the frequency and perceived reliability of blood pressure measurement in at-risk cats.

2022 AAFP/ISFM Cat Friendly Veterinary Interaction Guidelines: Approach and Handling Techniques

PRACTICAL RELEVANCE

The '2022 AAFP/ISFM Cat Friendly Veterinary Interaction Guidelines: Approach and Handling Techniques' (hereafter the 'Cat Friendly Veterinary Interaction Guidelines') support veterinary professionals with feline interactions and handling to reduce the impact of fear and other protective (negative) emotions, in so doing enhancing feline welfare and In implementing these Guidelines, team satisfaction and cat caregiver confidence in the veterinary team will increase as the result of efficient examinations, better experience, more reliable diagnostic testing and improved feline wellbeing. Veterinary professionals will learn the importance of understanding and appropriately responding to the current emotional state of the cat and tailoring each visit to the individual.

CLINICAL CHALLENGES

Cats have evolved with emotions and behaviors that are necessary for their survival as both a predator and prey species. A clinical setting and the required examinations and procedures to meet their physical health needs can result in behavioral responses to protective emotions. Cat friendly interactions require understanding, interpreting and appropriately responding to cats' emotional states and giving them a perceived sense of control while performing the required assessment.

EVIDENCE BASE

These Guidelines have been created by a Task Force of experts convened by the American Association of Feline Practitioners and the International Society of Feline Medicine, based on an extensive literature review and, where evidence is lacking, the authors' experience.

ENDORSEMENTS

These Guidelines have been endorsed by a number of groups and organizations, as detailed on page 1127 and at catvets.com/interactions and icatcare.org/cat-friendly-guidelines.

'The Mercury Challenge': feline systolic blood pressure in primary care practice - a European survey

OBJECTIVES

The aim of this study was to collect data from a substantial number of older cats having their systolic blood pressure (SBP) measured in a variety of clinical practices, to describe the findings and assess variables that affected the duration of assessment and the values obtained.

METHODS

An international (European-based) multicentre convenience sample survey of cats ⩾7 years of age attending veterinary clinics and having SBP measured as part of their clinical assessment. Information gathered included details of the cat, concomitant disease(s) or therapies, SBP results, device used, time taken to assess SBP and the demeanor of the cat.

RESULTS

Useable data were available from 8884 cats aged 7-26 years, from 811 clinics across 16 countries. The device used to measure SBP was Doppler in 47.4% and oscillometry in 48.5%. The demeanor of the cat was reported to be calm in 45.7%, anxious in 41.9% and nervous in 8.9%; and the duration of assessment was reported to be <5 mins in 50.4%, 5-10 minutes in 41.7% and >10 mins in 7.9%. Concomitant chronic kidney disease (CKD) was reported in 21.8%, hyperthyroidism in 12.0% or both in 3.1%. The median SBP was 150 mmHg (range 80-310), with 18.6% classified as hypertensive (SBP 160-179 mmHg) and 21.1% as severely hypertensive (SBP ⩾180 mmHg). The measured SBP was significantly affected by the cat's demeanor, duration of SBP assessment, presence of CKD and/or hyperthyroidism, the cat's sex and age, and the presence of concomitant therapy. The duration of SBP assessment was significantly affected by the cat's demeanor.

CONCLUSIONS AND RELEVANCE

In veterinary clinics, SBP can be measured in most cats within a short period of time using either Doppler or oscillometric equipment. The presence of CKD or hyperthyroidism was associated with significantly higher SBP values, and anxious or nervous cats had higher SBP values and took longer to obtain SBP assessments.

Does intravenous contrast medium administration result in altered renal biomarkers? A study in clinically stable cats with and without azotemia

OBJECTIVES

The aim of this study was to determine the prevalence of post-contrast acute kidney injury or comparable side effects on kidney function in cats receiving the non-ionic, iodinated agent ioversol and/or paramagnetic agent gadoteric acid.

METHODS

Fifty-two animals were divided into four groups on the basis of contrast medium administration for imaging: ioversol (n = 27), gadoteric acid (n = 12), dual contrast media (n = 4) or control, which received an infusion of isotone intravenous fluids only during anaesthesia (n = 9). Blood and urine samples were obtained three times after contrast administration and compared with values obtained prior to administration of the contrast medium. Creatinine (<1.60 mg/dl), symmetric dimethylarginine (SDMA; ⩽14 μg/dl), urine protein:creatinine ratio (UPC; <0.2) and critical differences for creatinine (<0.3 mg/dl) and SDMA (<5.98 μg/dl) were measured.

RESULTS

No significant short-term effects on mean creatinine, SDMA and UPC measurements were seen. Borderline proteinuria (UPC, 0.2-0.4) was detected in 11.4% of cases after contrast media administration. A UPC of more than 0.2 in five cases indicated that contrast media may affect kidney function, leading to (transient) proteinuria.

CONCLUSIONS AND RELEVANCE

This study found no side effect on renal function following the administration of ioversol or gadoteric acid, provided patients were adequately hydrated. However, the clinical relevance of proteinuria in some cats needs to be evaluated in future studies.

Feline comorbidities: The intermingled relationship between chronic kidney disease and hypertension

PRACTICAL RELEVANCE

Chronic kidney disease (CKD) is a highly prevalent disorder of senior cats. CKD is frequently diagnosed in association with hypertension, and the two conditions have an intermingled cause-and-effect relationship. Hypertensive target organ damage (TOD) to the eye, brain, heart and kidney significantly impacts the welfare of cats suffering from this comorbidity. Hypertension also drives proteinuria, which is an independent risk factor for progression and mortality in cats with CKD. Blood pressure monitoring and institution of effective antihypertensive treatment, where indicated, is therefore crucial in effective management of the feline CKD patient. Current guidelines recommend a target systolic blood pressure of <160 mmHg to minimise risk of TOD. Both amlodipine besylate and telmisartan are effective antihypertensive agents for use in these patients.

CLINICAL CHALLENGES

Clinical signs of hypertension may not be apparent to owners of affected cats until severe hypertensive TOD is present. Despite this, blood pressure monitoring in cats with CKD is still infrequently performed, and hypertension likely remains underdiagnosed in this population.

EVIDENCE BASE

This review is based upon evaluation of the currently available published literature, including relevant consensus statements. There is a large body of evidence supporting the association between hypertension and CKD in cats. However, significant aspects, such as the mechanisms behind this association, and effect of hypertension and antihypertensive treatment on mortality and progression of CKD, remain unclear. Further research is therefore required in order to improve understanding of these conditions.

Evaluation of coccygeal and radial artery Doppler blood pressure measurements in sick cats with and without abnormalities in tissue perfusion

OBJECTIVE

To compare systolic blood pressure measured by Doppler (SBP) taken from the coccygeal artery versus common digital branch of the radial artery in cats with normal and poor perfusion parameters.

DESIGN

Prospective, observational study.

SETTING

University Teaching Hospital.

ANIMALS

Eighty-five cats presenting to the emergency service for which prior emergency treatment was not received and a blood pressure was indicated on triage.

INTERVENTIONS

Systolic blood pressure was measured by Doppler using the radial and coccygeal arteries. Cats were categorized as having normal or poor tissue perfusion based on physical examination.

MEASUREMENTS AND MAIN RESULTS

Agreement was poor between coccygeal and radial SBP overall with absolute and relative bias (95% limits of agreement) of 23 (-51 to 96) mm Hg and 16% (-38% to 69%), respectively. In cats with poor perfusion, the agreement was absolute bias = 28 mm Hg and relative bias = 22% and with normal perfusion absolute bias = 22 mm Hg, and relative bias = 12%. The median (interquartile range) coccygeal SBP was significantly different from the radial SBP 141 (50) mm Hg versus 120 (45) mm Hg, P < 0.001. In multivariate linear regression, heart rate was negatively associated with coccygeal SBP (r²  = 0.088, P = 0.049), and pale mucous membrane color (P = 0.034) and poor pulse quality (P = 0.007) were independently associated with lower radial SBP (r²  = 0.18).

CONCLUSIONS

Median coccygeal SBP is significantly greater than radial SBP in sick cats with both normal perfusion and hypoperfusion. Agreement between coccygeal and radial SBP is poor in cats and cannot be used interchangeably. As clinically significant differences exist between sites, the authors recommend obtaining SBP from both sites initially and choosing to monitor and trend changes with the one site that correlates most with physical examination findings.

Effectiveness of intravenous fluid resuscitation in hypotensive cats: 82 cases (2012-2019)

OBJECTIVE

To evaluate the effectiveness of intravenous fluid resuscitation in hypotensive cats in an emergency room setting. Secondary objectives were to investigate changes in heart rate (HR) and body temperature (BT) in response to fluid resuscitation, and the association of these changes with patient survival.

DESIGN

Retrospective study.

SETTING

University teaching hospital.

ANIMALS

Eighty-two cats with confirmed hypotension.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Medical records from 2012 to 2019 were searched for cats that had documented systemic arterial hypotension (blood pressure measured using a Doppler ultrasonic flow probe [DBP] < 90 mm Hg) on presentation to the emergency room. Data collected included patient characteristics and DBP, HR, and BT before and after fluid resuscitation, type and volume of fluids administered, and outcome. The median DBP before and after resuscitative fluid therapy in all cats was 65 mm Hg (range, 20-85 mm Hg) and 80 mm Hg (range, 20-128 mm Hg), respectively (P < 0.001). However, only 30 cats (37%) were classified as responders to fluid resuscitation (DBP ≥ 90 mm Hg following bolus therapy). The mean HR and median BT before resuscitative fluid therapy was 159/min and 36.7°C. Following fluid resuscitation, where measured, the mean HR and median BT was 154/min (P = 1.00) and 35.9°C (P = 1.00). No significant differences in HR and BT were identified between responders and non-responders. Cats had a low survival rate of 7%. All survivors (n = 5) were initially bradycardic (HR < 160/min), compared to only 45% of non-survivors (P = 0.4).

CONCLUSIONS

Bolus fluid resuscitation effectively increases blood pressure in hypotensive cats; however, it does not result in normalization of blood pressure, HR, or BT in the majority of cases.

Effects of Waiting Room and Feline Facial Pheromone Experience on Blood Pressure in Cats

Obtaining accurate blood pressure measurements in cats is challenging due to the stressful nature of clinic visits. The objective of this study was to evaluate the effects of veterinary clinic waiting experiences and a feline pheromone spray on blood pressure in the cat. We hypothesized that reduced stress associated with bypassing the waiting room and use of synthetic feline facial pheromone (FFP) spray would result in lower blood pressure. A 2 × 2 factorial design involved two rooms and two FFP treatments. Thirty-nine healthy adult cats were recruited and were systematically assigned to four treatment combinations administered over four visits in 2016 and 2017. Cats were kept in the hospital waiting room or were taken directly to the exam room, with or without FFP treatment. All cats were then acclimated to the exam room for an additional 10 min, where vocalizations were recorded manually, before blood pressure measurements were collected using Doppler ultrasonography. Data were analyzed using generalized linear mixed models, with room × FFP interaction, visit, sex, and trial year in the model. There was no significant effect of waiting room by FFP interaction on blood pressure (n = 0.95). Mean blood pressure was significantly higher at visit 1 than visits 2 and 4 (P < 0.01), but higher at visit 3 than visit 2 (n = 0.02). Mean blood pressure was higher in males (n = 0.01), and males were more likely to be categorized as borderline hypertensive/hypertensive or severely hypertensive (n = 0.01). Number of vocalizations was significantly associated with waiting room by FFP interactions (P < 0.01), with fewer vocalizations associated with bypassing the waiting room and when FFP was provided. In conclusion, although we found some behavioral evidence supporting stress reduction when feline patients bypass the waiting room and are provided with FFP, these interventions did not result in lower blood pressure in a clinical setting.

Feline procedural sedation and analgesia: When, why and how

PRACTICAL RELEVANCE

Procedural sedation and analgesia (PSA) describes the process of depressing a patient's conscious state to perform unpleasant, minimally invasive procedures, and is part of the daily routine in feline medicine. Maintaining cardiopulmonary stability is critical while peforming PSA.

CLINICAL CHALLENGES

Decision-making with respect to drug choice and dosage regimen, taking into consideration the cat's health status, behavior, any concomitant diseases and the need for analgesia, represents an everyday challenge in feline practice. While PSA is commonly perceived to be an uneventful procedure, complications may arise, especially when cats that were meant to be sedated are actually anesthetized.

AIMS

This clinical article reviews key aspects of PSA in cats while exploring the literature and discussing complications and risk factors. Recommendations are given for patient assessment and preparation, clinical monitoring and fasting protocols, and there is discussion of how PSA protocols may change blood results and diagnostic tests. An overview of, and rationale for, building a PSA protocol, and the advantages and disadvantages of different classes of sedatives and anesthetics, is presented in a clinical context. Finally, injectable drug protocols are reported, supported by an evidence-based approach and clinical experience.