Cerebrovascular Reserve Capacity as a Predictor of Postoperative Delirium: A Pilot Study

Introduction: Postoperative delirium is a common complication after cardiac surgery with cardiopulmonary bypass (CPB). Compromised regulation of the cerebral circulation may be a predisposing factor for delirium. However, the potential relationship between cerebrovascular reserve capacity and delirium is unknown. The aim of this study was to investigate if impaired cerebrovascular reserve capacity was associated with postoperative delirium.Methods: Forty-two patients scheduled for cardiac surgery with CPB were recruited consecutively. All patients underwent preoperative transcranial Doppler (TCD) ultrasound with calculation of breath-hold index (BHI). BHI < 0.69 indicated impaired cerebrovascular reserve capacity. In addition, patients were examined with preoperative neuropsychological tests such as MMSE (Mini Mental State Examination) and AQT (A Quick Test of cognitive speed). Postoperative delirium was assessed using Nursing Delirium Screening Scale (Nu-DESC) in which a score of ≥2 was considered as delirium.Results: Six patients (14%) scored high for postoperative delirium and all demonstrated impaired preoperative cerebrovascular reserve capacity. Median (25th−75th percentile) BHI in patients with postoperative delirium was significantly lower compared to the non-delirium group [0.26 (−0.08–0.44) vs. 0.83 (0.57–1.08), p = 0.002]. Preoperative MMSE score was lower in patients who developed postoperative delirium (median, 25th−75th percentile; 26.5, 24–28 vs. 28.5, 27–29, p = 0.024). Similarly, patients with postoperative delirium also displayed a slower performance during the preoperative cognitive speed test AQT color and form (mean ± SD; 85.8 s ± 19.3 vs. 69.6 s ± 15.8, p = 0.043).Conclusion: The present findings suggest that an extended preoperative ultrasound protocol with TCD evaluation of cerebrovascular reserve capacity and neuropsychological tests may be valuable in identifying patients with increased risk of developing delirium after cardiac surgery.

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Association between serum biomarkers and postoperative delirium after cardiac surgery

Acta medica Lituanica ◽

10.6001/actamedica.v26i1.3949 ◽

2019 ◽

Vol 26 (1) ◽

pp. 8-10 ◽

Cited By ~ 2

Author(s):

Mindaugas Gailiušas ◽

Judita Andrejaitienė ◽

Edmundas Širvinskas ◽

Darijus Krasauskas ◽

Milda Švagždienė ◽

...

Keyword(s):

Cardiac Surgery ◽

Postoperative Delirium ◽

Neuronal Damage ◽

Artery Bypass ◽

Neuron Specific Enolase ◽

Perioperative Period ◽

Early Postoperative Period ◽

Blood Levels ◽

Increased Risk ◽

The Individual

Background. In cardiac surgery, patients face an increased risk of developing postoperative delirium (POD) that is associated with poor outcomes. Neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) have shown some promising results as potential tools for POD risk stratification, diagnosis, monitoring, and prognosis. Methods. Prospective single-centre study enrolled 44 patients undergoing elective coronary artery bypass grafting (CABG) and/ or valve procedures using cardiopulmonary bypass (CPB). The patients were assessed and monitored preoperatively, during surgery, and in the early postoperative period. The blood levels of NSE and GFAP were measured before and after surgery. The early POD was assessed by CAM-ICU criteria and patients were assigned to the POD group (with POD) or to the NPOD group (without POD) retrospectively. Results. The incidence of POD was 18.2%. After surgery, NSE significantly increased in the whole sample (p = 0.002). Comparing between groups, NSE significantly increased in the POD group after surgery (p = 0.042). ΔGFAP (before/after operation) for the whole sample was statistically significant (p = 0.022). There was a significant correlation between ΔGFAP and the lowest MAP during surgery in the POD group (p = 0.033). Conclusions. Our study demonstrated that NSE and GFAP are associated with early POD. An increase in NSE level during the perioperative period may be associated with subclinical neuronal damage. Serum GFAP levels show the damage of glial cells. Further studies are needed to find the factors influencing the individual limits of optimal MAP during surgery.

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