Non-invasive monitoring of blood pressure using the Philips Intellivue MP50 monitor cannot replace invasive blood pressure techniques in surgery patients under general anesthesia

The Philips Intellivue MP50 monitor provides a method for non‑invasive, near‑continuous blood pressure (BP) monitoring and is designed to be an alternative to direct intra‑arterial BP (IABP) measurement. However, no studies have specifically compared non‑invasive and invasive BP measurements using the monitor. The present retrospective study observed 515 patients undergoing surgery with general anesthesia, whose invasive (intra‑radial, femoral or dorsalis pedis artery) and non‑invasive (oscillometric) BP (NIBP) were monitored simultaneously using the monitor. These data were analyzed using correlations, regressions and Bland‑Altman plots. The patients were placed in a supine position during surgery. The correlation data for invasive BP and NIBP measurements were: for intra-radial measurements, r2=0.51 (bias and precision, 11.04±15.22 and 14.76±11.64 mmHg, respectively) for systolic BP (SBP) and r2=0.27 (6.17±11.95 and 9.77±9.25 mmHg, respectively) for diastolic BP (DBP); for intra‑femoral measurements: r2=0.57 (14.79±14.55 and 17.15±11.68 mmHg, respectively) for SBP and r2=0.45 (4.12±9.70 and 7.49±7.40 mmHg, respectively) for DBP; and for intra‑dorsalis pedis measurements: r2=0.33 (13.00±16.81 and 17.34±12.28 mmHg, respectively) for SBP and r2=0.30 (0.17±11.27 and 8.44±7.46 mmHg, respectively) for DBP. According to this data, the NIBP measured by the Philips Intellivue MP50 monitor showed low positive correlations and poor agreement with the IABP, as calculated by Bland‑Altman analysis. Therefore, the use of oscillometric BP measured by the monitor in surgery patients under general anesthesia is not generally recommended.