Pilot Study of the Feasibility of Multicenter NIRS Data Collection and Interventions for Desaturation in Cardiac Surgery

Brain injury after cardiac surgery is a chief source of patient mortality and healthcare
costs and can significantly impair quality of life. Reducing the burden of this complication
has wide public health implications. The broad manifestations of perioperative brain injury
include stroke, delirium, and cognitive decline.5 All forms of injury are believed to result
primarily from cerebral embolism and/or reduced cerebral blood flow (CBF). The risk for
cerebral hypoperfusion is likely the highest during cardiopulmonary bypass (CPB), when mean
arterial pressure (MAP) is kept low (~60 mmHg), particularly for patients who are aged and
who have cerebral vascular disease. Near-infrared spectroscopy (NIRS) is used increasingly
to monitor regional cerebral oxygen saturation (rScO2) in patients undergoing cardiac
surgery, although limited data show that it improves patient outcomes. Regardless, clinical
evidence supporting the efficacy of NIRS-based monitoring is needed urgently because the
cost of NIRS sensors (~$220/patient) could add $132 million annually to hospital costs for
cardiac surgery. We must address this issue quickly because the rising prevalence of NIRS
use and advocacy by experts and industry will likely soon result in NIRS becoming a standard
of care. We are in the process of submitting a multicenter, prospectively randomized
comparative effectiveness trial to assess the efficacy of NIRS monitoring in patients who
are undergoing coronary artery bypass graft (CABG) surgery with CPB, and/or valve surgery,
and who are at risk for brain injury. The goal of the planned proposal is to determine
whether interventions to correct rScO2 desaturations (value <50% or 20% reduction from room
air baseline) reduce the frequency of neurologic and other complications compared with
standard care (no clinical monitoring). In order to demonstrate feasibility of our proposal
we need to demonstrate the ability of the team to collect rScO2 data from multiple centers
and to show the ability of the team to properly follow an algorithm for treating rScO2
desaturations that occur during surgery. Thus, the aim of the current study is to collect
preliminary data to support our larger comparative effectiveness trial.

Inclusion Criteria: Patient inclusion criteria will be male or female patients >50 years
of age undergoing primary or re-operative CABG and/or cardiac valve surgery that requires
CPB who will have NIRS monitoring for clinical indications.

Exclusion Criteria: Emergency surgery