Comparison of indirect and direct blood pressure measurements in baboons during ketamine anaesthesia

Background: The aim of this study was to assess agreement between different methods of blood pressure measurement in anaesthetised baboons. Methods: Systolic and diastolic blood pressure (SBP and DBP) were measured in anaesthetised baboons using intra-arterial radiotelemetry, automated oscillometry and mercury sphygmomanometry. Correlation between the different methods was assessed. Results: The correlation between intra-arterial radiotelemetry and automated oscillometry was 0.9 (P < 0.001) for SBP and 0.9 (P < 0.001) for DBP. Between-method differences were -4.4 ± 7.2 mm Hg for SBP and -3.4 ± 7.1 mm Hg for DBP. For automated oscillometry vs. mercury sphygmomanometry, correlation was 0.4 for both SBP (P < 0.001) and DBP (P < 0.001). Between-method differences were 7.9 ± 12.7 mm Hg for SBP and 7.3 ± 12.6 mm Hg for DBP. Conclusions: Our study demonstrates that automated oscillometry may be an appropriate alternative to telemetry for measuring blood pressure in anaesthetised baboons.