Comparison of invasive and noninvasive blood pressure measurements in critically ill patients receiving norepinephrine
摘要
Blood pressure monitoring is crucial in critically ill patients, with invasive arterial blood pressure (IABP) recognized as the gold standard. Noninvasive blood pressure (NIBP) is widely used but may differ from IABP, particularly in patients receiving norepinephrine. This study evaluated the agreement between IABP and NIBP and the impact of the norepinephrine dosage on the accuracy of NIBP in septic shock patients.
MethodsThis prospective observational study was conducted in a 36-bed ICU (April 2022–April 2023) and included 84 patients with septic shock receiving norepinephrine. IABP was measured via a radial artery catheter, and NIBP was recorded simultaneously from the contralateral arm. Patients were grouped by norepinephrine dose: ≤ 0.25, 0.25–0.50, and ≥ 0.50 mcg/kg/min. Agreement was assessed via Bland-Altman and error grid analyses, with a focus on the mean blood pressure (MBP) thresholds (≥ 65 mmHg and < 65 mmHg).
ResultsAmong the 2,104 paired measurements, significant discrepancies were observed between the IABP and NIBP across all dose groups(p < 0.001). Discrepancies increased with higher norepinephrine doses, particularly at an MBP ≥ 65 mmHg, with biases of -3.89 mmHg (≤ 0.25 mcg/kg/min) and − 6.81 mmHg (≥ 0.50 mcg/kg/min). Error grid analysis revealed that 47.2% of MBP ≥ 65 mmHg measurements fell into clinically significant risk zones (B-E) at high doses. In patients aged > 65 years, significant differences were observed in all pressures (p < 0.001), whereas younger patients showed discrepancies only in the mean and diastolic pressures.
ConclusionsThis study demonstrated significant discrepancies between IABP and NIBP in critically ill patients receiving norepinephrine, particularly at higher doses and in patients with MBP ≥ 65 mmHg. These findings highlight the limitations of NIBP monitoring in this population and support the importance of IABP monitoring in selected high-risk patients, while suggesting that NIBP monitoring may remain acceptable in more hemodynamically stable individuals. Applying these considerations in clinical practice may help optimize blood pressure monitoring strategies in the ICU.