Intraoperative Invasive Blood Pressure Monitoring in Flap-Based Lower Extremity Reconstruction.

Abstract

Despite the lack of clear indications for the use of intra-arterial lines (IALs) for intraoperative hemodynamic monitoring, they are often used in a variety of settings. In this retrospective review of patients undergoing free tissue transfer (FTT) for lower extremity (LE) reconstruction, we sought to (1) identify patient factors associated with IAL placement, (2) compare hemodynamic measurements obtained via IAL versus noninvasive blood pressure (NIBP) monitoring, and (3) investigate whether method of hemodynamic monitoring affected intraoperative administration of blood pressure-altering medications. Patients undergoing LE FTT from January 2017 through June 2020 were retrospectively reviewed. Patients were pair matched based on flap donor site, sex, and body mass index to identify patient factors associated with IAL placement. Methods previously described by Bland and Altman (Lancet. 1986;327:307-310) were used to investigate agreement between IAL and NIBP measurements. Sixty-eight patients were included with 34 patients in the IAL group and 34 in the NIBP group. Older patients (P = 0.03) and those with a higher Charlson Comorbidity Index (P = 0.05) were significantly more likely to have an IAL placed. Agreement analysis demonstrated that mean arterial pressures calculated from IAL readings were as much as 31 points lower or 28 points higher than those from NIBP. Bias calculations with this extent of difference suggest poor correlation between IAL readings and NIBP (R2 = 0.3027). There was no significant difference between groups in rate of administration of blood-pressure altering medications. Surgeons should consider the risks and benefits of IAL placement on a case-by-case basis, particularly for patients who are young and healthy. Our findings highlight the need for clearer guidance regarding the use of IAL in patients undergoing LE FTT.