Concordância entre dois monitores oscilométricos portáteis e a pressão invasiva em felinos anestesiados

This study compared the agreement of analog (petMAPclassic) and digital (petMAPgraphic) oscillometric monitors with invasive blood pressure (IBP) in anesthetized cats. Eight cats (3.2 to 5.5 kg) were pre-medicated with IM midazolam/ketamine /methadone and anesthetized with IV propofol (6.2 ± 3.2 mg/kg) followed by and isoflurane (end-tidal concentration: 0.8 to 3.1 vol%). The cuffs of the two monitors were positioned in the distal third of the radius-ulna (thoracic limb) and at the base of the tail. Based on the IBP (dorsal metatarsal artery catheterization), the MBP values were modified to values between 40 and 100 mmHg by changing the isoflurane concentration and/or administering dopamine (3.0 to 23.4 μg/kg/min, IV). The differences between methods were analyzed by the Bland-Altman method for repeated measures on the same individual (positive difference: overestimation of IBP). The petMAPclassic and the petMAPgraphic provided poor estimates of invasive SBP, with upper and lower limits of agreement (mean bias ± 1.96 SD) ranging from 32.7 to 40.5 and -18.6 to -24.2 mmHg, respectively. Comparatively with IPB, MBP estimated by the petMAPclassic presented a mean bias (± 1.96 SD) (mmHg) of -1.1 (10.6/-12.9) and -1.9 (12.7/-16.5) in the tail and thoracic limb, respectively. The MBP measured by petMAPgraphic differed from IBP by -0.1 (12.0/-12.3) (tail) and 0.2 (13.2/-12.7) (thoracic limb). DBP estimated by the petMAPclassic differed from IBP by -6.1 (5.5/-17.7) (tail) and -6.1 (7.1/-19.2) (thoracic limb). The bias obtained with the petMAPgraphic between for DBP values was -4.4 (7.3/-16.0) (tail) and -4.3 (7.2/-15.8) (thoracic limb). Only the DBP values measured by the petMAPgraphic and the MBP measured by both oscillometric monitors met the accuracy criteria required by the "Association for the Advancement of Medical Instrumentation" (mean difference ≤ 5 mmHg with SD ≤ 8 mmHg). The MBP values measured by both monitors may be used for clinical decisions.