Comprehensive Summary
This single-center prospective pilot study compared continuous (cNIBP) versus intermittent non-invasive blood pressure (iNIBP) monitoring in prehospital patients presenting with shock. Twenty-five adult patients were monitored simultaneously using the Edwards HemoSphere cNIBP and standard iNIBP cuffs. The primary endpoint was the agreement between cNIBP and iNIBP. Secondary endpoints included missed hypotension (mean arterial pressure (MAP) < 60 mmHg) and correlation of cNIBP/iNIBP with tissue oxygenation (StO2). The study found significantly higher MAP readings with the iNIBP system by 10.77 mmHg (p<0.01) compared to cNIBP measurements. Systolic and diastolic blood pressures (BP) were overestimated by iNIBP monitoring. Bland-Altman analysis demonstrated a systematic bias and poor interchangeability between methods. In three of 25 patients, iNIBP failed to detect hypotension (MAP<60 mmHg) captured by cNIBP measurements. Correlation with StO2 was poor, suggesting it may complement, but not replace BP monitoring.
Outcomes and Implications
Rapid and accurate BP assessment is crucial for early treatment initiation in shock patients. This study suggests that the current standard, iNIBP, may overestimate BP and miss critical hypotension in the prehospital setting. Therefore, cNIBP monitoring may improve hemodynamic instability detection. However, given the trial’s preliminary nature, single-center design and small sample size, the clinical implementation timeline is unclear. Multi-center clinical trials will need to verify the frequency of missed hypotension and evaluate whether earlier detection translates into faster interventions and improved patient outcomes.