Quantifying neurological function in patients undergoing transcatheter aortic valve implantation.

Background: Transcatheter aortic valve implantation (TAVI) is a routine procedure that is often performed on older adults that are high-risk patients with severe aortic stenosis. Patients after TAVI may experience neurological complications. However, there is a lack of objective neurological testing available for patients undergoing cardiac surgery. Objective: This brief communication seeks to explore the use of robotic technology to quantify distinctive patterns of visuospatial, sensorimotor, and cognitive functioning in patients undergoing TAVI. Methods: Patients undergoing TAVI were recruited for this prospective observational study. Prior to their procedure, study participants performed four robotic reaching tasks using the Kinarm robotic system. Patients repeated the assessment three months after their TAVI procedure. Significant changes in overall task score and parameters were determined. Results: Ten patients were recruited and included in this brief report. In a simple reaching task, patients show significant improvement in performance post-TAVI. However, patients do not improve nor worsen in a complex reaching task after TAVI. Similarly, patients demonstrate impairments in both trail making tasks before and after their TAVI procedure. Conclusions: This study captures the variability in neurological functioning in older patients undergoing TAVI. Robotic technology and quantified assessment procedures can be extremely valuable for detecting perioperative neurological impairments in this patient population.

Cerebral oximetry and preventing neurological complication post-cardiac surgery: a systematic review.

OBJECTIVES: This systematic review aims to provide an up-to-date summary of the current literature examining the relationship between intraoperative regional cerebral oxygen saturation and neurological complications after cardiac surgery. METHODS: Observational and interventional studies investigating the link between regional cerebral oxygen saturation and postoperative delirium, cognitive dysfunction and stroke were included. After database searching and study screening, study characteristics and major findings were extracted. RESULTS: Twenty-seven studies were identified. Of the observational studies (n = 17), 8 reported that regional cerebral oxygen desaturations were significantly associated with neurological complications after cardiac surgery. Of the interventional studies (n = 10), 3 provided evidence for monitoring cerebral oximetry during cardiac surgery as a means of reducing incidence of postoperative cognitive dysfunction or stroke. There was significant heterogeneity in the tools and rigor used to diagnose neurological complications. CONCLUSIONS: Studies to date show an inconsistent relationship between regional cerebral oxygen saturation and neurological outcomes after cardiac surgery, and lack of clear benefit of targeting cerebral oximetry to minimize neurological complications. Standardized assessments, definitions of impairment and desaturation thresholds will help determine the benefits of cerebral oximetry monitoring during cardiac surgery.

Quantified pre-operative neurological dysfunction predicts outcome after coronary artery bypass surgery.

AIMS: Patients undergoing coronary artery bypass grafting (CABG) surgery may experience neurological impairment. We examined whether intraoperative regional cerebral oxygen saturation (rSO2) and neurological dysfunction prior to surgery, measured by robotic technology, are important predictors of post-operative performance following CABG surgery. METHODS: Adult patients undergoing CABG surgery were recruited for this single-center prospective observational study. Intraoperative rSO2 was captured using the FORESIGHT cerebral oximeter. Neurological assessment was performed pre-operatively and 3 months following surgery using robotic technology and a standardized pen-and-paper assessment. Linear regression models were generated to determine the predictive ability of both intraoperative rSO2 and pre-operative performance on post-operative neurological outcome. RESULTS: Forty patients had complete data available for analysis. Quantified pre-operative performance accounted for a significantly larger amount of variance in post-operative outcome compared to intraoperative rSO2. In particular, pre-operative scoring on a cognitive visuospatial task accounted for 82.2% of variance in post-operative performance (b = 0.937, t(37) = 12.98, p = 1.28e-5). DISCUSSION: Our results suggest that pre-operative performance is a stronger indicator of post-operative neurological outcome than intraoperative rSO2, and should be included as an important variable when elucidating the relationship between cerebral oxygen levels and post-operative neurological impairment. Rigorous neurological assessment prior to surgery can provide valuable information about each individual patient's path to recovery. CONCLUSION: Using robotic technology, quantified neurological impairment prior to CABG surgery may better predict post-operative neurological outcomes, compared to intraoperative rSO2 values.

Road to recovery: a study protocol quantifying neurological outcome in cardiac surgery patients and the role of cerebral oximetry.

INTRODUCTION: Patients undergoing cardiac surgery may experience both short-term and long-term postoperative neurological problems. However, the underlying cause of this impairment is unclear. Regional cerebral oxygen saturation (rSO2) levels may play a role in the development of acute dysfunction, known as postoperative delirium, in addition to longer term outcomes after cardiac surgery. Yet the degree of impairment has been difficult to define, partly due to subjective methods of assessments. This study aims to fill this knowledge gap by determining the relationship between rSO2, postoperative delirium and long-term neurological outcome after cardiac surgery using quantitative robotic technology. METHODS AND ANALYSIS: 95 patients scheduled for elective cardiac surgery will be recruited for this single-centre prospective observational study. Patients will be assessed before as well as 3 and 12 months after their surgery using the Kinarm End-Point Lab and standardised tasks. Intraoperatively, rSO2 and other haemodynamic data will be collected for the duration of the procedure. Following their operation, patients will also be screened daily for delirium during their hospital stay. ETHICS AND DISSEMINATION: This study has been approved by the Health Sciences Research Ethics Board at Queen's University (DMED-1672-14). The results of this study will be published in a peer-review journal and presented at international and/or national conferences as poster or oral presentations. Participants wishing to know the results of this study will be contacted directly on data publication. TRIAL REGISTRATION NUMBER: NCT04081649.

The relationship between cerebral oxygen saturation and quantitative metrics of neurological function after coronary bypass surgery: a feasibility study.

BACKGROUND: It is well-known that patients undergoing coronary artery bypass grafting (CABG) surgery may experience neurological dysfunction following their operation. However, the nature of this dysfunction has not been properly quantified. Furthermore, the relationship between postoperative impairment and cerebral oxygen saturation during surgery has remained unclear. This study aims to define the feasibility of using robotic technology to quantify post-CABG neurocognitive function, and to correlate these objective metrics with intraoperative cerebral oxygenation. METHODS: Neurological function was tested using robotic technology and a standardized questionnaire before and 3 months after surgery. In addition, frontal lobe cerebral oxygenation was recorded using the FORESIGHT near-infrared spectrometer for the duration of the operation. Pre- and postoperative neurological assessment was performed for 24 participants. Of those 24, 20 participants had cerebral oxygenation recorded during their surgery. RESULTS: The cerebral oximeter captured 97.2% of the data. Majority of patients experienced no significant decline in overall neurocognitive function. Abnormal postoperative scores were most frequent in a sensorimotor task that involved additional cognitive load. In this reverse visually guided reaching task, postoperative scores significantly correlated with mean and minimum intraoperative cerebral oxygenation values, with lower values being associated with worse performance. CONCLUSIONS: It is feasible to use robotic technology as a quantitative and objective neurocognitive assessment method for patients undergoing CABG. The relationship between quantitative metrics of neurocognitive function and intraoperative cerebral oxygenation warrants further investigation.