Relative cerebral hyperperfusion during cardiopulmonary bypass is associated with risk for postoperative delirium: a cross-sectional cohort study

Abstract

Background Our objective was to evaluate if changes in on-pump cerebral blood flow, relative to the pre-bypass baseline, are associated with the risk for postoperative delirium (POD) following cardiac surgery. Methods In 47 consecutive adult patients, right middle cerebral artery blood flow velocity (MCAV) was assessed using transcranial Doppler sonography. Individual values, measured during cardiopulmonary bypass (CPB), were normalized to the pre-bypass baseline value and termed MCAV rel . An MCAV rel > 100% was defined as cerebral hyperperfusion. Prevalence of POD was assessed using the Confusion Assessment Method for the Intensive Care Unit. Results Overall prevalence of POD was 27%. In the subgroup without POD, 32% of patients had experienced relative cerebral hyperperfusion during CPB, compared to 67% in the subgroup with POD ( p < 0.05). The mean averaged MCAV rel was 90 (±21) % in the no-POD group vs. 112 (±32) % in the POD group (p < 0.05), and patients developing delirium experienced cerebral hyperperfusion during CPB for about 39 (±35) min, compared to 6 (±11) min in the group without POD ( p < 0.001). In a subcohort with pre-bypass baseline MCAV (MCAV bas ) below the median MCAV bas of the whole cohort, prevalence of POD was 17% when MCAV rel during CPB was kept below 100%, but increased to 53% when these patients actually experienced relative cerebral hyperperfusion. Conclusions Our results suggest a critical role for cerebral hyperperfusion in the pathogenesis of POD following on-pump open-heart surgery, recommending a more individualized hemodynamic management, especially in the population at risk. Electronic supplementary material The online version of this article (10.1186/s12871-019-0705-y) contains supplementary material, which is available to authorized users.

Intra-operative hyperoxia and the risk of delirium in elderly patients after cardiac surgery

“…In a recently published study by Thudium et al a relationship was found between cerebral hyperperfusion and post cardiac surgery delirium. In the study the authors examined right middle cerebral artery blood flow during CBP using the transcranial Doppler [21]. In our study we did not plan to measure cerebral blood flow, but the cardiac index during CBP was similar in both groups, with and without postoperative delirium (mean CI=2,5 l/min/m 2 , P=0.69).…”

Neuromonitoring with Intermittent Transcranial Doppler Sonography and Continuous Near Infrared Spectroscopy in Aortic Arch Surgery: An Observational Study

“…Denault has recently proposed a modi ed NIRS algorithm in which ultrasound imaging plays a role in hemodynamic evaluation and cerebral imaging in case of increased intracranial pressure. (12) We suggest that ultrasound should become even more central in cerebral monitoring to con rm NIRS ndings and to evaluate cerebral hemodynamics.…”

Risk Factors for Delayed Neurocognitive Recovery According to Brain Biomarkers and Cerebral Blood Flow Velocity

“…This study stated that blood flow velocity changes and pulsatility play an important role in postoperative neurologic outcomes [ 6 ]. Thudium M. indicated that relative cerebral hyperperfusion also disrupts cerebral autoregulation and might play a significant role in dNCR development [ 4 ]. Individual values were normalized to the pre-bypass baseline value, and MCA BFV > 100% was defined as cerebral hyperperfusion.…”

“…Many researchers have identified that neuropsychological complications emerge from insufficient cerebral perfusion [ 4 , 5 , 6 , 7 ]. Transcranial Doppler sonography (TCD) could provide information about middle cerebral artery (MCA) blood flow velocity (BFV) during surgery to detect hypoperfusion episodes and cerebral embolism.…”