Comparison of noninvasive blood pressure monitoring with invasive arterial pressure monitoring in medical ICU patients with septic shock.

OBJECTIVE: In the critically ill, the insertion of peripheral arterial catheters to monitor hemodynamics is a low-risk procedure, but carries the potential for complications. This study was designed to compare invasive and noninvasive blood pressure measurements in patients with septic shock in a medical ICU.

PATIENTS AND METHODS: We carried out a prospective observational study of patients admitted with septic shock and a radially inserted peripheral arterial catheter in the medical ICU with 31 adult patients who underwent four pairs of simultaneous noninvasive and invasive blood pressure measurements (124 comparisons), with the invasive blood pressure taken as the gold standard. Agreements between invasive and noninvasive blood pressure methods were assessed using Bland-Altman analysis, and clinical significance was determined by the European Society of Hypertension criteria.

RESULTS: In all patients, noninvasive systolic (P=0.0385), diastolic (P<0.0001), and mean arterial pressures (P<0.0001) did correlate statistically with invasive measurements; however, all noninvasive pressure measurements did not correlate clinically according to the European Society of Hypertension criteria.

CONCLUSION: In our patients admitted to the medical ICU with septic shock, noninvasive blood pressure monitoring did not clinically correlate with invasive blood pressure measurements.