The effect of relative cerebral hyperperfusion during cardiac surgery with cardiopulmonary bypass to delayed neurocognitive recovery.

OBJECTIVE: Delayed neurocognitive recovery (dNCR) remains a common complication after surgery and the incidence of it is determined 30-80% after cardiac surgery with cardiac bypass (CPB) in eldery patients. Many researchers have identified that neuropsychological complications emerge from insufficient cerebral perfusion. Relative cerebral hyperperfusion also disrupts cerebral autoregulation and might play a significant role in dNCR development. The aim of this study is to determine hyperperfusion in the middle cerebral artery during CPB influence to dNCR development and brain biomarker glial fibrillary acidic protein (GFAP) impact in diagnosing dNCR. DESIGNS AND METHODS: This prospective - case control study included patients undergoing elective coronary artery bypass grafting or/and valve surgery with CPB. For cognitive evaluation 101 patients completed Addenbrooke's cognitive examination - ACE-III. To determine mild cognitive dysfunction, cut - off 88 was chosen. Mean BFV was monitored with transcranial Doppler ultrasonography (TCD) and performed before surgery, after induction of anaesthesia, during CPB and after surgery. Preoperative BFV was converted to 100% and used as a baseline. The percentage change of cerebral blood flow velocity during CPB was calculated from baseline. Patients with decreased blood flow velocity were included for further investigation. To measure glial fibrillary acidic protein, blood samples were collected after anaesthesia induction, 24 and 48 h after the surgery. According to the ACE-III test results, patients with relative hyperperfusion were divided into two groups: with Delayed neurocognitive recovery and without dNCR (non-dNCR group). RESULTS: 101 patients were examined, 67 (69.1%) men and 29 (29.9%) women, age 67.9 (SD 9.2) Increased percentage of BFV was determined for 40 (39.60%) patients. There were no differences in sex, haematocrit, paCO2, aortic cross-clamping or CPB time between the two groups. Percentage change of BFV was 105.60% in the non-dNCR group and 132.29% in the dNCR group, p = .033. Patients who developed dNCR in the early post-surgical period were significantly older, p < .001 and had a lower baseline of BFV, p = .004. GFAP concentration significantly increased in the dNCR group 48 hours after surgery, compared to the non-dNCR group, p = .01. CONCLUSIONS: Relative hyperperfusion during CPB may cause dNCR. Elderly patients are sensitive to blood flow velocity acceleration during CPB. GFAP concentration increased 48 h after surgery in dNCR group but did not have any connection with risk factors.

Risk Factors Associated with an Increased Risk of Deep Sternal Wound Infections in Patients After Coronary Artery Bypass Grafting and Heart Defect Surgery.

BACKGROUND: Despite improvements over time with regard to morbidity, mortality, and long-term survival, deep sternal wound infection (DSWI) continues to be a major complication after open-heart surgery. This is why it is important to identify possible risk factors for postoperative development of DSWI in patients undergoing coronary artery bypass grafting and valve replacement. The aim of this study was to identify the risk factors for postoperative development of deep sternal wound infection in patients after coronary artery bypass grafting and heart defect surgery at the Department of Thoracic, Cardiac, and Vascular Surgery of the Hospital of Lithuanian University of Health Sciences. METHODS: This retrospective study analyzed 201 patients, who underwent coronary artery bypass grafting and heart defect surgery between January 2017 and December 2018. The case group contained 45 patients, who had to be reoperated because of deep sternal wound infection, and the control group consisted of 156 randomly selected patients. For descriptive statistics, we used means, median values, ranges, standard deviations, and 95% confidence intervals, where appropriate. Categorical data were analyzed using the chi-square or Fisher's exact test. Student T-test and Mann-Whitney used to compare numerical variables. Logistic regression model adjusting for age and gender was used to compare the risk of infection. A P-value of < 0.05 was considered to be statistically significant. SPSS 26.0 was used for calculations. RESULTS: Logistic regression analysis revealed that independent risk factors for sternal wound infection were high BMI (odds ratio [OR] 1.15, CI 1.06-1.24), preoperative CRP (OR 1.08, CI 1.01-1.16), long duration of cardiopulmonary bypass (OR 1.02, CI 1.01-1.03), intraoperative anemia (OR 0.97, CI 0.95-0.99), and postoperative CRP concentration (OR 1.10; CI 1.05-1.16). CONCLUSIONS: Preoperative assessment to identify obese individuals as being at risk and techniques to minimize the duration of surgery and intraoperative blood loss may help reduce postoperative deep sternal wound infections.

Effects of Combined and General Anesthesia on Cognitive Functions for Patients Undergoing Cardiac Surgery Under CPB.

BACKGROUND: Patients may experience a variety of neurological complications after heart surgery. The most common complication observed in clinical practice is delayed neurocognitive recovery (dNCR). The role of the anesthesiologist is very important, as the risk of dNCR may be reduced, depending on the anesthesia tactic chosen. Although the possibility that neuropsychological complications are less common in patients undergoing combined anesthesia (general + epidural) than in patients undergoing general anesthesia is not yet confirmed, the results are being discussed. The aim of this study was to determine impact of combined anesthesia (general + epidural) on cognitive functions of patients after cardiac surgery. METHODS: The prospective, case-controlled study included 80 patients undergoing cardiac surgery from 2015 to 2017 at the Department of Cardiothoracic and Vascular Surgery in the Hospital of Lithuanian University of Health Sciences Kauno Klinikos. After approval from the local bioethics center, informed consent was obtained from all study participants. Inclusion criteria were age 51 to 80 years, elective cardiac surgery, left ventricular ejection fraction > 35%, anamnesis of not using agents affecting the central nervous system, absence of neuropathology, and sufficient renal function. Exclusion criteria were patients suffering from diseases causing cognitive function or using agents affecting the central nervous system, emergency or re-surgery, carotid artery atherosclerosis with artery diameter 50 or more percent reduction, and a patient's disagreement. MMSE test and 6-CIT test were used for a cognitive function assessment, Trail making test and WAIS Digital Symbol Substitution test were used for psychomotor function assessment. All tests were used a day before surgery and seven days after surgery. According to the planned anesthesia, patients were assigned into two groups: 1 - combined general + epidural anesthesia and 2 - general anesthesia. Standardized protocol of anesthesia was followed for all patients. Preoperative patients and surgery factors, preoperative and postoperative neuropsychological test results were recorded. RESULTS: Eighty patients were enrolled in the study. Both groups did not differ in demographic, perioperative values, and baseline (preoperative) test results. Postoperative (7th day) WAIS (P = .042) and 6-item cognitive impairment (P = .016) test results were statistically different when comparing the GA and CA groups. Comparing preoperative and postoperative test results, there was a significant decline in the WAIS test score in the GA group (P = .013).

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

Background and Objectives: The aim of this study is to identify risk factors for the development of delayed neurocognitive recovery (dNCR). Methods: 140 patients underwent neurocognitive evaluations (Adenbrooke, MoCa, trial making, and CAM test) and middle cerebral artery (MCA) blood flow velocity (BFV) measurements, one day before cardiac surgery. BFV was re-evaluated after anesthesia induction, before the beginning, middle, end, and after cardiopulmonary bypass (CPB) and postsurgery. To measure glial fibrillary acidic protein (GFAP) and neurofilament heavy chain (Nf-H), blood samples were collected after anesthesia induction, 24 and 48 h after the surgery. Neurocognitive evaluation was repeated 7-10 days after surgery. According to the results, patients were divided into two groups: with dNCR (dNCR group) and without dNCR (non-dNCR group). Results: 101 patients completed participation in this research. GFAP increased in both the non-dNCR group (p < 0.01) and in the dNCR group (p < 0.01), but there was no difference between the groups (after 24 h, p 0.342; after 48 h, p 0.273). Nf-H increased in both groups (p < 0.01), but there was no difference between them (after 24 h, p = 0.240; after 48 h, p = 0.597). MCA BFV was significantly lower in the dNCR group during the bypass (37.13 cm/s SD 7.70 versus 43.40 cm/s SD 9.56; p = 0.001) and after surgery (40.54 cm/s SD 11.21 versus 47.6 cm/s SD 12.01; p = 0.003). Results of neurocognitive tests correlated with CO2 concentration (Pearson's r 0.40, p < 0.01), hematocrit (r 0.42, p < 0.01), MCA BFV during bypass (r 0.41, p < 0.01), and age (r -0.533, p < 0.01). The probability of developing dNCR increases 1.21 times with every one year of increased age (p < 0.01). The probability of developing dNCR increases 1.07 times with a decrease of BFV within 1 cm/s during bypass (p = 0.02). Conclusion: Risk factors contributing to dNCR among the tested patients were older age and middle cerebral artery blood flow velocity decrease during bypass.

The influence of blood flow velocity changes to postoperative cognitive dysfunction development in patients undergoing heart surgery with cardiopulmonary bypass.

BACKGROUND: The aim of this study was to compare blood flow velocity changes in the middle cerebral artery before, during and after heart surgery with cardiopulmonary bypass for patients with and without postoperative cognitive dysfunction. MATERIALS AND METHODS: A total of 100 patients, undergoing elective coronary artery bypass grafting or/and valve surgery enrolled in the study. A neurocognitive test evaluation included Adenbrooke, Mini-Mental State Examination and Trial Making test before and 7-10 days after surgery. Middle cerebral artery mean blood flow velocity was evaluated 1 day before the surgery, after anaesthesia induction, before cardiopulmonary bypass, at the beginning, ending and after cardiopulmonary bypass, and post surgery in intensive care unit. Blood samples for glial fibrillary acidic protein were measured after anaesthesia induction, 24 hours and 48 hours after surgery. According to neurocognitive tests results patients were divided in to two groups: patients with and without postoperative cognitive dysfunction. RESULTS: Of the 100, 86 patients completed investigation. After induction, blood flow velocity of the middle cerebral artery was lower in postoperative cognitive dysfunction group (41.2; min 27.91, max 49.47) than in the H group (41.2, min 21.9, max 84.3) p = 0.034, and during cardiopulmonary bypass, blood flow velocity of the middle cerebral artery was lower in the postoperative cognitive dysfunction group (37.35, min 26.6, max 44.02) than the H group (42.3, min 20.1, max 86.5), p = 0.001. After the surgery, blood flow velocity of the middle cerebral artery was lower in the postoperative cognitive dysfunction group (40.7, min 29.7, max 50.4) than in the H group (45.3, min 34.12, max 59.88), p = 0.05. Results of cognitive tests had weak correlation (rho, 0.391) with middle cerebral artery's blood flow velocity after anaesthesia induction (p = 0.001) and during bypass (p = 0.018). The receiver operating characteristic analysis showed that the blood flow velocity of the middle cerebral artery during bypass (area under the curve = 0.735) was a fair predictor for postoperative cognitive dysfunction (p = 0.001). No significant correlations were found among glial fibrillary acidic protein, middle cerebral artery blood flow velocity, and cognitive tests results. CONCLUSION: Middle cerebral artery's blood flow velocity was decreased after anaesthesia induction and during cardiopulmonary bypass for patients with postoperative cognitive dysfunction comparing with their blood flow velocity preoperatively. Blood flow velocity during bypass has diagnostic value for postoperative cognitive dysfunction. Brain biomarker glial fibrillary acidic protein is not helpful in diagnosing postoperative cognitive dysfunction.