Most patients with non-hypertensive diseases at a critical care resuscitation unit require arterial pressure monitoring: a prospective observational study

Background: Blood pressure (BP) monitoring is essential for patient care. Invasive arterial BP (IABP) is more accurate than non-invasive BP (NIBP), although the clinical significance of this difference is unknown. We hypothesized that IABP would result in a change of management (COM) among patients with non-hypertensive diseases in the acute phase of resuscitation.

Methods: This prospective study included adults admitted to the Critical Care Resuscitation Unit (CCRU) with non-hypertensive disease from February 1, 2019, to May 31, 2021. Management plans to maintain a mean arterial pressure >65 mmHg (1 mmHg=0.133 kPa) were recorded in real time for both NIBP and IABP measurements. A COM was defined as a discrepancy between IABP and NIBP that resulted in an increase/decrease or addition/discontinuation of a medication/infusion. Classification and regression tree analysis identified significant variables associated with a COM and assigned relative variable importance (RVI) values.

Results: Among the 206 patients analyzed, a COM occurred in 94 (45.6% [94/206]) patients. The most common COM was an increase in current infusion dosages (40 patients, 19.4%). Patients receiving norepinephrine at arterial cannulation were more likely to have a COM compared with those without (45 [47.9%] vs. 32 [28.6%], P=0.004). Receiving norepinephrine (relative variable importance [RVI] 100%) was the most significant factor associated with a COM. No complications were identified with IABP use.

Conclusion: A COM occurred in 94 (45.6%) non-hypertensive patients in the CCRU. Receiving vasopressors was the greatest factor associated with COM. Clinicians should consider IABP monitoring more often in non-hypertensive patients requiring norepinephrine in the acute resuscitation phase. Further studies are necessary to confirm the risk-to-benefit ratios of IABP among these high-risk patients.