Agreement between invasive and oscillometric arterial blood pressure measurements using the LifeWindow multiparameter monitor and two cuff sizes in anesthetized adult horses

ObjectiveTo assess agreement between oscillometric noninvasive blood pressure (NIBP) measurements using LifeWindow monitors (LW9xVet and LW6000V) and invasive blood pressure (IBP). To assess the agreement of NIBP readings using a ratio of cuff width to mid-cannon circumference of 25% and 40%.Study designProspective, randomized clinical study.AnimalsA total of 43 adult horses undergoing general anesthesia in dorsal recumbency for different procedures.MethodsAnesthetic protocols varied according to clinician preference. IBP measurement was achieved after cannulation of the facial artery and connection to an appropriately positioned transducer connected to one of two LifeWindow multiparameter monitors (models: LW6000V and LW9xVet). Accuracy of monitors was checked daily using a mercury manometer. For each horse, NIBP was measured with two cuff widths (corresponding to 25% or 40% of mid-cannon bone circumference), both connected to the same monitor, and six paired IBP/NIBP readings were recorded (at least 3 minutes between readings). NIBP values were corrected to the relative level of the xiphoid process. A Bland–Altman analysis for repeated measures was used to assess bias (NIBP–IBP) and limits of agreement (LOAs).ResultsThe 40% cuff width systolic arterial pressure [SAP; bias 7.9 mmHg, LOA –26.6 to 42.3; mean arterial pressure (MAP): bias 4.9 mmHg, LOA –28.2 to 38.0; diastolic arterial pressure (DAP): bias 4.2 mmHg, LOA –31.4 to 39.7)] performed better than the 25% cuff width (SAP: bias 26.4 mmHg, LOA –21.0 to 73.9; MAP: bias 15.7 mmHg, LOA –23.8 to 55.2; DAP: bias 10.9 mmHg, LOA –33.2 to 54.9).Conclusions and clinical relevanceUsing the LifeWindow multiparameter monitor in anesthetized horses, the 40% cuff width provided better agreement with IBP; however, both cuff sizes and both monitor models failed to meet American College of Veterinary Internal Medicine Consensus Statement Guidelines.     

Evaluation of an indirect oscillometric blood pressure monitor in normotensive and hypotensive anesthetized dogs

Objective – To determine the accuracy and precision of an oscillometric noninvasive blood pressure device as a predictor of invasive direct blood pressure in healthy anesthetized hypotensive and normotensive dogs. Design – Prospective observational study. Setting – University teaching hospital. Animals – Eight crossbred adult dogs. Interventions – Anesthesia was induced with propofol and maintained with isoflurane. A catheter was placed in the dorsal pedal artery to record systolic, mean, and diastolic arterial blood pressures (aSAP, aMAP, and aDAP, respectively). The noninvasive blood pressure device cuff was placed around the contralateral front limb to record noninvasive systolic, mean, and diastolic blood pressure (nSAP, nMAP, and nDAP). Two states of blood pressure (BP) were studied: baseline state was established by keeping end‐tidal isoflurane concentration at 1.2±0.1%. The hypotensive state was achieved by maintaining the same isoflurane concentration while withdrawing approximately 40% of the animal's blood volume until aMAP was stable at approximately 40 mm Hg. At the end of the study, blood was returned to the animal and it was allowed to recover from anesthesia. Measurements and Main Results – Agreement between the direct and indirect BP measurements was determined by the Bland‐Altman method. The SAP and MAP but not DAP bias varied significantly between each BP state. Normotensive absolute biases (mean [SD]) for SAP, MAP, and DAP were ?14.7 mm Hg (15.5 mm Hg), ?16.4 mm Hg (12.1 mm Hg), and ?14.1 mm Hg (15.8 mm Hg), respectively. Absolute biases during the hypotensive state for SAP, MAP, and DAP were ?32 mm Hg (22.6 mm Hg), ?24.2 mm Hg (19.5 mm Hg), and ?16.8 mm Hg (17.2 mm Hg), respectively. Conclusion – The oscillometric device was not reliably predictive of intra‐arterial BP during hypotension associated with acute hemorrhage.     

Agreement between invasive blood pressures measured in three peripheral arteries in anaesthetized horses under clinical conditions

Objective

To determine agreement between invasive blood pressures measured in three peripheral arteries in anaesthetized horses undergoing elective surgery.

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

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

Agreement between invasive blood pressure measured centrally and peripherally in anaesthetized horses

Objective

To determine the agreement of invasive blood pressure measured in the facial, metatarsal and carotid arteries, and evaluate the effects of two haemodynamic conditions on agreement.

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.     

Agreement between invasive and oscillometric arterial blood pressure measurement using a high-definition oscillometric device in normotensive New Zealand White rabbits using two different anaesthetic protocols

ObjectiveTo use American College of Veterinary Internal Medicine (ACVIM) criteria to evaluate a high-definition oscillometric (HDO) blood pressure monitoring device versus invasive blood pressure (IBP) measurement in normotensive rabbits anaesthetized with two different anaesthetic protocols.Study designProspective experimental study.AnimalsA group of 20 healthy adult New Zealand White rabbits weighing 4.36 ± 0.37 kg (mean ± standard deviation).Materials and methodsRabbits were premedicated with butorphanol 0.5 mg kg^–1 and midazolam 0.5 mg kg^–1 subcutaneously (SC, group BMA) or ketamine 25 mg kg^–1 and medetomidine 0.4 mg kg^–1 SC (group KM). Anaesthesia was induced with alfaxalone administered intravenously (group BMA) or isoflurane by face mask (group KM) and maintained with isoflurane in oxygen. IBP was measured from the central auricular artery. The cuff for the HDO monitor was placed distal to the left elbow and distal to the left tarsus. Agreement between invasive and HDO measurements was evaluated using Bland–Altman method.ResultsIn group KM there was better agreement between the HDO device and IBP when the cuff was placed on the thoracic limb, with 100% and 91% of the readings for mean (MAP) and diastolic arterial pressure (DAP), respectively, within 10 mmHg of the IBP measurements. The agreement, although worse, also met the ACVIM criteria for systolic arterial pressure (SAP; 53% of the readings within 10 mmHg). In group BMA, the device met the criteria with the cuff on the thoracic limb only, and only for MAP and DAP (73% and 75% of the measurements within 10 mmHg of the IBP, respectively) but not for SAP (12%).Conclusion and clinical relevanceThe HDO device met most of the ACVIM criteria for noninvasive blood pressure measurement in anaesthetized rabbits, specifically when the cuff was placed distal to the elbow and the anaesthetic protocol included ketamine and medetomidine.     

Validation of the oscillometric blood pressure monitor Vet20 SunTech in anesthetized healthy cats

ObjectiveTo evaluate a veterinary-specific oscillometric noninvasive blood pressure (NIBP) system according to the guidelines of the American College of Veterinary Internal Medicine (ACVIM) Consensus Statement.Study designProspective clinical study.AnimalsA total of 33 client-owned cats (20 females and 13 males).MethodsCats were premedicated with methadone (0.3 mg kg⁻¹) and alfaxalone (2 mg kg⁻¹) intramuscularly. After 15 minutes anesthesia was induced with isoflurane (3%) in 100% oxygen by facemask while breathing spontaneously. A 22 gauge catheter was placed in the median caudal artery and systolic (SAP), diastolic (DAP) and mean (MAP) arterial pressures were measured. NIBP measurements were collected by placing the cuff (40% of limb circumference) on the right or left antebrachium. The agreement between the two methods was evaluated with the Bland–Altman methods, and the oscillometric NIBP device was evaluated using the ACVIM guidelines for validation of devices.ResultsData from 30 of the 33 cats were analyzed. Five paired measurements were taken from each cat, totaling 150 paired measurements. Mean bias (limits of agreements) for SAP, DAP and MAP were 2.7 (−22.7 to 28.1), 0.9 (−22.3 to 24.2) and 1.3 (−20.4 to 23.0). The oscillometric NIBP passed all validation criteria, except correlation which was <0.9 for SAP, DAP and MAP.Conclusions and clinical relevanceThe Vet20 did not meet all validation criteria by the ACVIM. However, all criteria except correlation were met.     

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

ObjectivesTo 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 DesignProspective clinical study.AnimalsA group of 13 captive adult cheetahs.MethodsCheetahs 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.ResultsA 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 relevanceWhen 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.     

Agreement between direct, oscillometric and Doppler ultrasound blood pressures using three different cuff positions in anesthetized dogs

ObjectiveTo evaluate the agreement between invasive blood pressure (IBP) and Doppler ultrasound blood pressure (DUBP) using three cuff positions and oscillometric blood pressure (OBP) in anesthetized dogs.Study designProspective study.AnimalsNine adult dogs weighing 14.5–29.5 kg.MethodsThe cuff was placed above and below the tarsus, and above the carpus with the DUBP and above the carpus with the OBP monitor. Based on IBP recorded via a dorsal pedal artery catheter, conditions of low, normal, and high systolic arterial pressures [SAP (mmHg) <90, between 90 and 140, and >140, respectively] were induced by changes in isoflurane concentrations and/or dopamine administration. Mean biases ± 2 SD (limits of agreement) were determined.ResultsAt high blood pressures, regardless of cuff position, SAP determinations with the DUBP underestimated invasive SAP values by more than 20 mmHg in most instances. With the DUBP, cuff placement above the tarsus yielded better agreement with invasive SAP during low blood pressures (0.2 ± 16 mmHg). The OBP underestimated SAP during high blood pressures (?42 ± 42 mmHg) and yielded better agreement with IBP for mean (MAP) and diastolic (DAP) arterial pressure measurements [overall bias: 2 ± 15 mmHg (MAP) and 0.2 ± 16 mmHg (DAP)].ConclusionsAgreement of SAP determinations with the DUBP is poor at SAP > 140 mmHg, regardless of cuff placement. Measurement error of the DUBP with the cuff placed above the tarsus is clinically acceptable during low blood pressures. Agreement of MAP and DAP measurements with this OBP monitor compared with IBP was clinically acceptable over a wide pressure range.Clinical relevanceWith the DUBP device, placing the cuff above the tarsus allows reasonable agreement with IBP obtained via dorsal pedal artery catheterization. Only MAP and DAP provide reasonable estimates of direct blood pressure with the OBP monitor evaluated.     

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

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

Comparison of arterial blood pressure measurements obtained invasively or oscillometrically using a Datex S/5 Compact monitor in anaesthetised adult horses

Objective

To assess agreement between noninvasive blood pressure (NIBP) oscillometrically-derived values from a multiparameter monitor (Datex Ohmeda S/5 Compact) with those obtained by invasive blood pressure (IBP) measurement in anaesthetised horses undergoing elective surgery.

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

ObjectiveTo determine the accuracy of an oscillometric blood pressure monitor in anesthetized sheep.Study designProspective study.AnimalsTwenty healthy adult sheep, 11 males and nine females, weighing 63.6 ± 8.6 kg.MethodsAfter premedication with buprenorphine or transdermal fentanyl, anesthesia was induced with ketamine‐midazolam and maintained with isoflurane and ketamine, 1.2 mg kg^?1 hour^?1, ± lidocaine, 3 mg kg^?1 hour^?1. Invasive blood pressure measurements were obtained from an auricular arterial catheter and noninvasive measurements were from a cuff on the metatarsus or antebrachium. Simultaneous invasive and noninvasive measurements were recorded over a range (55–111 mmHg) of mean arterial pressures (MAP). Isoflurane concentration was increased to decrease MAP and decreasing the isoflurane concentration and infusing dobutamine achieved higher pressures. Invasive and noninvasive measurements were compared.ResultsCorrelation (R²) was good between the two methods of measurement (average of three consecutive readings) for systolic (SAP) (0.87), diastolic (DAP) (0.86), and mean (0.90) arterial pressures (p < 0.001). Bias ± SD between noninvasive and invasive measurements for SAP was 3 ± 8 mmHg, for DAP was ?10 ± 7 mmHg, and MAP was ?7 ± 6 mmHg. There was no significant difference between the average of three measurements and use of the first measurement. Correlations using the first measurement were SAP (0.82), DAP (0.84), and MAP (0.89). Bias ± SD for SAP was 3 ±10 mmHg, for DAP was ?11 ± 7 mmHg, and MAP was ?7 ± 6 mmHg. The oscillometric monitor slightly overestimated SAP and underestimated DAP and MAP for both average values and the first reading.Conclusions and clinical relevanceThis oscillometric model provided MAP measurements that were acceptable by ACVIM standards. MAP measurements with this monitor were lower than those found with the invasive technique so a clinical diagnosis of hypotension may be made in sheep that are not hypotensive.     

Agreement of high definition oscillometry with direct arterial blood pressure measurement at different blood pressure ranges in horses under general anaesthesia

ObjectiveTo determine the agreement of high definition oscillometry (HDO) with direct arterial blood pressure measurements in normotensive, hypotensive and hypertensive horses during general anaesthesia.Study designExperimental study.AnimalsSeven healthy warmblood horses, aged 3–11 years, weighing 470–565 kg.MethodsMeasurements from a HDO device with the cuff placed around the base of the tail were compared with pressures measured invasively from the facial artery. High blood pressures were induced by intravenous (IV) administration of dobutamine (5 μg kg⁻¹ minute⁻¹) over ten minutes followed by norepinephrine (0.1 mg kg⁻¹ IV) and low pressures by increasing the inspired fraction of isoflurane and administration of nitroglycerine (0.05 mg kg⁻¹ IV). For analysis three pressure levels were determined: high (MAP>110 mmHg), normal (60 mmHgResultsA total of 245 paired measurements of systolic (SAP), mean (MAP) and diastolic (DAP) pressures were obtained. The HDO device underestimated blood pressure at hypertensive and normotensive levels and overestimated blood pressure at hypotensive levels. Best agreement was obtained for SAP and MAP within normotensive limits. At normotension, bias ± standard deviation for SAP, MAP and DAP were 0.1 ± 19.4 mmHg, 0.5 ± 14.0, 4.7 ± 15.6, respectively. At high pressure levels bias and SD were 26.1 ± 37.3 (SAP), 4.2 ± 19.4 (MAP), 1.5 ± 16.8 (DAP) and at low pressures -20.0 ± 20.9 (SAP), -11.4 ± 19.6 (MAP), -4.7 ± 20.1 (DAP), with HDO measurements at a MAP <50 mmHg often failing.Conclusion and clinical relevanceGood agreement with invasive arterial blood pressures was obtained with HDO at normotensive levels in horses. At high and low pressure ranges HDO was unreliable. Therefore, if haemodynamic instability is expected, invasive measurement remains preferable.     

A study of measurement of noninvasive blood pressure with the oscillometric device,Sentinel, in isoflurane‐anaesthetized horses

ObjectiveTo assess accuracy of noninvasive blood pressure (NIBP) measured by oscillometric device Sentinel compared to invasive blood pressure (IBP) in anaesthetized horses undergoing surgery. To assess if differences between the NIBP measured by the Sentinel and IBP are associated with recumbency, cuff placement, weight of the horse or acepromazine premedication and to describe usefulness of the Sentinel.Study designProspective study examining replicates of simultaneous NIBP and IBP measurements.AnimalsTwenty-nine horses.MethodsInvasive blood pressure was measured via a catheter in the facial artery, transverse facial artery or metatarsal artery. NIBP was measured using appropriate size cuffs placed on one of two metacarpal or metatarsal bones or the tail in random order. With both techniques systolic (SAP), mean (MAP), and diastolic (DAP) arterial blood pressures and heart rates (HR) were recorded. A mixed effects model compared the IBP to the NIBP values and assessed potential effects of catheter placement, localisation of the cuffs in combination with recumbency, weight of the horse or acepromazine premedication.ResultsNoninvasive blood pressure yielded higher measurements than IBP. Agreement varied with recumbency and cuff position. Estimated mean differences between the two methods decreased from SAP (lateral recumbency: range -5.3 to -56.0 mmHg; dorsal recumbency: range 0.8 to -20.7 mmHg), to MAP (lateral recumbency: range -1.8 to -19.0 mmHg; dorsal recumbency: range 13.9 to -16.4 mmHg) to DAP (lateral recumbency: range 0.5 to -6.6 mmHg; dorsal recumbency: range 21.0 to -15.5 mmHg). NIBP measurement was approximately two times more variable than IBP measurement. No significant difference between IBP and NIBP due to horse's weight or acepromazine premedication was found. In 227 of 1047 (21.7%) measurements the Sentinel did not deliver a result.Conclusion and clinical relevanceAccording to the high variability of NIBP compared to IBP, NIBP measurements as measured by the Sentinel in the manner described here are not considered as an appropriate alternative to IBP to measure blood pressure in anaesthetized horses.     

The effects of two endotracheal tube cuff inflation pressures on liquid aspiration and tracheal wall damage in horses

OBJECTIVE: To investigate the effect of endotracheal tube cuff inflation pressure on the occurrence of liquid aspiration and tracheal wall damage. STUDY DESIGN: Prospective, randomized experimental study. ANIMALS: Ten healthy horses, weighing 535 +/- 55 kg. METHODS: Horses were anesthetized, orotracheally intubated, placed in dorsal recumbency, and maintained on isoflurane in oxygen with controlled ventilation for 175 +/- 15 minutes. The horses were randomly assigned to an endotracheal cuff pressure of 80-100 or 120 cm H2O. The cuff pressure was continuously monitored and maintained at a constant pressure. Methylene blue in saline was instilled proximal to the cuff. After euthanasia, the trachea was opened distal to the endotracheal tube tip to check for evidence of dye leaking past the cuff. The cervical trachea was then resected and opened longitudinally for gross and histologic examinations. RESULTS: No blue staining was found distal to the cuff in any horse. Visual examination of the tracheal mucosa revealed hyperemic and hemorrhagic lesions at the site of the cuff contact. Histologic changes included epithelium attenuation or erosion, submucosal neutrophilic infiltration, and submucosal hemorrhages. Lesions were absent or less extensive in the lower cuff pressure group as compared to the high cuff pressure group. CONCLUSIONS: The endotracheal tube cuff produced a seal sufficient to prevent leakage in both groups. Tracheal wall damage was more severe and occurred more frequently in the higher cuff pressure group. CLINICAL RELEVANCE: Tracheal mucosal damage induced by cuff inflation is pressure-dependent. Cuff pressure monitoring is recommended.     

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

ObjectiveTo 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 designProspective clinical study.AnimalsA group of 34 client-owned adult dogs.MethodsDogs 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)].ResultsThe 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 relevanceThe 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.