A protocol based on hypotension probability indicator vs. standard care to prevent intraoperative hypotension during supratentorial brain surgery: a prospective randomized pilot trial.

BACKGROUND

To test the hypothesis that Hypotension probability indicator (HPI) driven hemodynamic protocol use may decrease the exposition to hypotension (mean arterial pressure below 65 mmHg) during supratentorial intracranial procedures.

METHODS

Patients undergoing supratentorial tumor resection under general anesthesia (ASA 1-3) were included into this randomized single center-controlled pilot trial. Patients in the control group (COV, N.=20) were managed based on the institutional standard to avoid hypotension. Patients in the intervention (INT, N.=20) group were managed using a protocol triggered by the HPI above 85 based on the stroke volume variation, dynamic elastance, and cardiac index parameters. The number of patients experiencing hypotension (mean arterial pressure below 65 mmHg) during the whole procedure and anesthesia maintenance phase was the primary outcome variable. The number of hypotensive periods, time spent in hypotension, and hypotension dose served as secondary outcome variables. Other clinically relevant parameters and postsurgical outcomes were screened.

RESULTS

The number of patients who never experienced hypotension was significantly lower in the INT group during the anesthesia maintenance phase (10 (50%) vs. 16 (80%); P=0.049). In several other hemodynamic outcomes, a distinct numerical, but statistically non-significant trend towards lower hypotension exposition was observed. There were no significant differences in clinically relevant parameters.

CONCLUSIONS

In this pilot trial, the HPI-based protocol decreased the incidence of hypotension during the anesthesia maintenance but non-significant trends among secondary outcomes were also documented. Larger trials are needed to confirm our findings.