Postoperative Cerebral Dysfunction Research Articles

Postoperative cerebral dysfunction: potential risk factors

Postoperative cerebral dysfunction: potential risk factors

Delirium in cardiac surgery: epidemiology, pathogenesis and prevention highlights (Review)

Symptomatic delirium of the early postoperative period is a qualitative disorder (clouding) of consciousness that is deferred, occurs under mainly vascular, inflammatory and metabolic alterations, manifests by variant behavioral disorders. Three clinical studies were conducted to assess the state of the brain after the most frequent elective cardiac surgery coronary bypass surgery, open-heart valve surgery, open-heart and endovascular aortic valve surgery. 306 patients were included in the listed studies, the controls included the results of the examination of 120 patients who underwent elective eversion carotid endarterectomy and 15 patients who underwent elective abdominal aortic prosthetics. Thus, 441 patients underwent perioperative neurological examination according to a single algorithm. According to the results of the conducted studies, the frequency of symptomatic delirium of the early postoperative period during elective cardiac surgery is 1214%. Symptomatic delirium of the early postoperative period commonly develops 13 days after surgery, the average duration is from 1 to 3 days. Symptomatic delirium of the early postoperative period also increases the likelihood of subsequent development of other clinical types of postoperative cerebral dysfunction perioperative stroke and deferred cognitive impairment. Most of the symptomatic delirium of the early postoperative period risk factors are preoperative and have vascular origin. Combined use of CAM-ICU and RASS scales is recommended for screening diagnostics of symptomatic delirium of the early postoperative period. The increase of the number of cardiac surgeries demonstrates the necessity of the further improvement of perioperative cerebroprotection, the main directions are promptly diagnosis and correction of risk factors, as well as the use of non-pharmacological and pharmacological methods of brain protection, including the original four-component (inosine, nicotinamide, riboflavin, succinic acid) neuroprotector with cytoprotective and antihypoxic effects, as well as meglumine sodium succinate with antihypoxic and anti-inflammatory effects.

Послеоперационная мозговая дисфункция при протезировании аортального клапана сердца

Study Objective: To study the incidence and the structure of the postoperative cerebral dysfunction after open and endovascular aortic valve replacement surgery, and to identify the risk factors and the methods of prevention of postoperative cerebral dysfunction after the open aortic valve replacement surgery. Study Design: Prospective cohort study. Materials and Methods. The study involved 114 patients (92 men and 22 women) aged 67 [58; 76] years, who undergone elective aortic valve replacement surgery. All patients were divided into three groups: “open surgery” (n = 82), “cerebroprotection” (n = 16) and “X-ray surgery” (n = 16). In the “open surgery” and “cerebroprotection” groups, patients undergo open aortic valve replacement surgery with cardiopulmonary bypass, in the “X-ray surgery” group transcatheter aortic valve implantation is performed. In the “cerebroprotection” group patients additionally received the 1.5% solution of meglumine sodium succinate in the early postoperative period. Study Results. The postoperative cerebral dysfunction was diagnosed in 41.2% of patients, the incidence of the postoperative cerebral dysfunction did not differ in the study groups. In the group “cerebroprotection” there was a shorter duration of symptomatic delirium of the early postoperative period (p = 0.0441) compared with the group “open surgery”. We identified 18 risk factors for postoperative cerebral dysfunction and its clinical types and two cerebroprotective factors — a body mass index more than 25 kg/m2 and the use of the meglumine sodium succinate in the early postoperative period. Conclusion. Aortic valve replacement surgery is characterized by the high incidence of the postoperative cerebral dysfunction, further improvement of the methods of the perioperative cerebroprotection is required. Keywords: postoperative cerebral dysfunction, perioperative stroke, symptomatic delirium of the early postoperative period, postoperative cognitive dysfunction, perioperative cerebroprotection, aortic valve replacement.

The structure and risk factors of the postoperative cerebral dysfunction in oncosurgery

Aim of the research was to study the features of the structure of postoperative cerebral dysfunction, establishing the risk factors for the development of postoperative cerebral dysfunction and for the each of the clinical types during operations for malignant neoplasms of the chest and abdomen. The study was conducted in 2 stages: a retrospective study based on medical records and a prospective study. In a retrospective study by the method of directed selection from 93,129 clinical cases of patients, 47 cases of patients with acute stroke after surgery were selected. In prospective study, 102 patients (69 men, 33 women) aged 38 to 85 years were examined, the median age was 67 years. They were divided into two study groups: thoracic, abdominal. In a retrospective study, the incidence of perioperative stroke was 0.05%. In a prospective study of surgical operations for malignant neoplasms of the chest and abdomen, the incidence of postoperative cerebral dysfunction was 34%, perioperative stroke 2%, symptomatic delirium of the early postoperative period 11%, deferred cognitive impairment 31%. Statistical processing of the prospective study data revealed 10 risk factors for postoperative cerebral dysfunction, 12 risk factors for perioperative stroke, 7 risk factors for symptomatic delirium of the early postoperative period, and 6 risk factors for deferred cognitive impairment. For each of the clinical types of postoperative cerebral dysfunction the Charlson comorbidity index has a significant predictive value, and therefore it seems appropriate to include this parameter in the preoperative examination algorithm (3 tables, bibliography: 8 refs)

Postoperative cerebral dysfunction in carotid endarterectomy — a modern prevention strategy

Based on 48 foreign and domestic publications, a systematic review on the prevention of postoperative cerebral dysfunction (POCD) that develops after reconstructive operations on the carotid arteries was carried out. Main conclusions. Reconstructive operations on the carotid arteries, which are the leading direction in the prevention of ischemic strokes in stenosing atherosclerotic lesions of the brachiocephalic arteries and, primarily, of the internal carotid artery, can cause the development of postoperative cerebral dysfunction. The current strategy for reducing the risks of cognitive impairment after surgery is not fully developed and requires further research. English version of the article on pp. 165-172 is available at URL: https://panor.ru/articles/postoperative-cognitive-dysfunction-after-carotid-endarterectomy-current-preventive-strategy/63915.html

EVALUATION OF THE FREQUENCY OF DEVELOPMENT OF POSTOPERATIVE CEREBRAL DYSFUNCTION DEPENDING ON THE METHOD OF PROSTHETICS OF THE AORTAL VALVE OF THE HEART

The worldwide trend towards an increase in average life expectancy is associated with an increase in the prevalence of acquired heart defects, which at a certain stage dictates the need for cardiac surgery. We examined 72 patients (52 men and 20 women) who underwent planned aortic valve prosthetics. All patients were divided into two groups depending on the method of implantation of the prosthesis: the first group-aortic valve replacement when performing open surgery using cardiopulmonary bypass, the second group-endovascular prosthetics. The first group included 48 men and 18 women, whose average age was 66 years old; the second group included 4 men and 2 women, whose average age was 73 years. All patients underwent a comprehensive examination in the preoperative and postoperative periods, including an anamnesis assessment, a neurological examination using the NIHSS and Rankin scales, neuropsychological (Montreal Cognitive Assessment and frontal dysfunction battery) and psychometric (Hospital anxiety and depression scale) tests, as well as computed tomography the head in identifying clinical signs of perioperative stroke. Postoperative cerebral dysfunction was diagnosed in 44.4% (n = 32) of patients. The overall incidence of clinical types of postoperative cerebral dysfunction was as follows: perioperative stroke - 2.8% (n = 2), symptomatic delirium of the early postoperative period - 13.9% (n = 10), delayed cognitive impairment - 33.3% (n = 24) There were no acute clinical types of postoperative cerebral dysfunction in the endovascular treatment group. Delayed cognitive impairment in both groups were detected in 33.3% (in the first group n = 22, in the second group n = 2). According to the results of the study, acute clinical types of postoperative cerebral dysfunction were absent in the endovascular treatment group, cognitive impairment was detected in 1/3 of the patients in both groups.

Midterm cerebral outcomes of Stanford type A aortic dissection in patients who underwent novel triple-branched stent graft implantation combined with intraoperative monitoring of regional cerebral oxygen saturation.

ObjectiveThe aim of this study was to evaluate the cerebral outcomes of patients underwent novel triple‐branched stent graft implantation combined with the intraoperative monitoring of regional cerebral oxygen saturation.MethodsOne hundred thirty‐seven consecutive patients who underwent the surgery of triple‐branched stent graft implantation in our department were enrolled in this retrospective case‐control study. The patients in group A received brain protection based on the intraoperative monitoring of regional cerebral oxygen saturation and the patients in group B received conventional brain protection. The general clinical data, the types of corrective surgeries, the intraoperative situations, the postoperative complications, and the midterm outcomes of the patients were analyzed.ResultsThe incidence of postoperative cerebral dysfunction in the patients of group A was significantly lower than that in the patients in group B (3.2% vs 14.9%, P = .020). We found significant differences in the incubation times (30.3 ± 22.1 vs 42.3 ± 27.9 hours, P = .014), the lengths of intensive care unit stay (58.0 ± 54.3 vs 79.7 ± 55.5 hours, P = .004), and the hospital stays (19.3 ± 6.7 vs 24.9 ± 17.3 days, P = .045). A descending trend in the mortality rates was observed between the patients in the two groups based on the 20 months of observation; however, this trend was not statistically significant (1.6% vs 6.8%, P = .218).ConclusionsThe novel triple‐branched stent graft implantation procedure combined with intraoperative monitoring of the regional cerebral oxygen saturation was an effective treatment for Stanford type A aortic dissection, with a relatively low incidence of postoperative cerebral dysfunction.

Characteristics of postoperative cerebral dysfunction depending on the type and position of the implanted prosthetic heart valve

To study the prevalence and structure of postoperative cerebral dysfunction depending on the type and position of the implanted prosthetic heart valve in patients who underwent surgery for the acquired heart valve disease. The study included 115 patients (70 men and 45 women; 64 [56; 72] years old), who underwent elective replacement or repair surgery for the acquired heart valve disease. The postoperative cerebral dysfunction was diagnosed in 40.9% patients, including replacement in the aortic position (45.5%), in the mitral position (55%), in several positions (20%). Replacement surgery was accompanied by three clinical types of postoperative cerebral dysfunction and repair surgery - by deferred cognitive impairment only. Postoperative cerebral dysfunction after the replacement in the mitral position was more common (odds ratio 4.47, 95% confidence interval 1.21-18.35, p=0.041), including its acute clinical types - perioperative stroke and symptomatic delirium of the early postoperative period (p=0.029), compared to that after the repair heart valve surgery. After the replacement in the aortic position, acute clinical types of postoperative cerebral dysfunction were more common (p=0.036). After the replacement with biological prosthesis, symptomatic delirium of the early postoperative period was more common (p=0.047). The occurrence of the deferred cognitive impairment didn't depend on the type and position of the implanted prosthetic heart valve.

Perioperative stroke in heart valve surgery: pathogenesis, clinical findings, diagnosis, prevention, treatment

To study risk factors, characteristics of clinical symptoms and diagnosis, and possibilities of prevention of perioperative stroke and other clinical types of cerebral dysfunction in main types of heart valve surgery. The study included 83 patients, aged 63 (54; 70) years, undergoing heart valve surgery with cardiopulmonary bypass. Postoperative cerebral dysfunction was diagnosed in 37.3% of cases, including perioperative stroke in 3.6% of cases. In cases of aortic stenosis, the frequency of perioperative stroke was 9.5%. The cardioembolic subtype of perioperative ischemic stroke in cardiac valve surgery was most likely. The risk factors of the symptomatic delirium of the early postoperative period are: age over 75 years, preoperative frontal dysfunction, duration of artificial respiratory care more than 20 hours after the surgery. The results suggest the efficacy of preventive use of cytoflavin for reducing the frequency and severity of perioperative stroke and symptomatic delirium of the early postoperative period in heart valve surgery with cardiopulmonary bypass.

Postoperative cerebral dysfunction

To study the structure, risk factors and methods of prevention of postoperative brain dysfunction on the example of coronary artery bypass surgery with cardiopulmonary bypass. The study included 77 patients who undergone elective coronary artery bypass surgery at the beating heart (22 patients) or with cardiopulmonary bypass (55 patients, including 24 patients, who received cerebroprotective treatment with cytoflavin in the preoperative period). All patients underwent dynamic (pre- and postoperative) neurological, neuropsychological, instrumental examinations. The postoperative cerebral dysfunction was diagnosed in 34 (44,2%) patients. The frequency of the clinical types of postoperative cerebral dysfunction significantly differed: perioperative stroke - 3 (3,9%) cases, symptomatic delirium of the early postoperative period - 11 (14,3%) cases, delayed cognitive impairment - 28 (36,4%) cases. The risk factors of postoperative cerebral dysfunction after the coronary artery bypass surgery with cardiopulmonary bypass were identified. Preventive preoperative use of the neuroprotective drug cytoflavin reduces the severity of delayed cognitive impairment after the coronary artery bypass surgery with cardiopulmonary bypass and has a good safety profile. An analysis of the literature data and the results of our own studies show that postoperative cerebral dysfunction is the nosological entity with various etiological factors, pathogenetic mechanisms and the characteristic clinical types, which has an effect on the outcome of surgical treatment.

Postoperative cerebral dysfunction in the elderly: Diagnosis and prophylaxis

Post-operative cerebral dysfunction includes delirium, usually occurring early and reversible, and post-operative cognitive disorders, usually occurring later and prolonged. This is a frequent complication in patients older than 75 years old. The two neurological pictures are often inter-related. The pathophysiology of both entities is similar and related to post-operative neuro-inflammation; therefore onset may occur independently of any surgical complication. Post-operative cerebral dysfunction is a serious organic complication. Reduction of inflammation represents the most logical preventive measure but currently there are no studies that show this to be effective. Prevention therefore means combining several minor measures, elements that fit well into programs of enhanced post-operative recovery after surgery. Diminished pre-operative cognitive status being a major risk factor, pre-operative rehabilitation combining nutritional, physical and cognitive support can be helpful.

Leukocyte Depletion During Extracorporeal Circulation Allows Better Organ Protection but Does Not Change Hospital Outcomes

Leukocyte filtration has been reported to reduce inflammatory damage during cardiopulmonary bypass. We evaluated the role of leukocyte filtration on hospital outcome and postoperative morbidity. Eighty-two consecutive patients who underwent isolated coronary artery bypass grafting were randomly assigned (1:1) to receive leukocyte filters on both arterial and cardioplegia lines or standard arterial filters during cardiopulmonary bypass. Hospital outcome, postoperative markers of morbidity, and biochemical assays were compared. Data were collected preoperatively, intraoperatively, and postoperatively. Costs for patients receiving intraoperative leukofiltration were compared with control patients getting standard arterial filters. Hospital mortality and intensive care unit and hospital length of stay were similar. Although duration of ventilation and incidence of pneumonia were comparable, leukocyte-depleted patients showed a higher ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (p = 0.008) and lower need for postoperative noninvasive ventilation (p = 0.041). Control patients showed higher need for continuous furosemide infusion (p = 0.013) and for renal replacement therapy (p = 0.014), in association with higher serum creatinine (p = 0.038) and blood urea (p = 0.18) and lower glomerular filtration rate (p = 0.038). Leukocyte-depleted patients required lower doses of inotropic agents (p = 0.56), whereas troponin I leakage and incidence of postoperative atrial fibrillation were comparable. No differences were found in terms of postoperative cerebral dysfunction or neutrophil and platelet counts, as well as postoperative bleeding and need for transfusions. Finally, leukodepletion proved significantly cost-beneficial, with a 37% cost reduction. Although hospital outcomes were similar in terms of mortality and length of stay, the improvements in pulmonary, renal, and myocardial function, in association with the cost benefit, justify the use of leukocyte-depletion filters in the clinical practice.

Low preoperative endocannabinoid levels predict delirium after cardiac surgery

Introduction: The endocannabinoid system is a neurobiologic system consisting of two endogenous endocannabinoids (ECs), anandamide (ANA) and 2-arachidonoylglycerol (2-AG), and two receptors, CB1 and CB2. Activation of the ECS reduces inflammatory damage to the brain. Acute postoperative cerebral dysfunction (ACD) is a common adverse consequence of cardiac surgery, possibly associated to inflammatory response. Administration of statins decreases the proinflammatory cytokines after cardiac surgery. This study investigated the association between ECS, statins and cerebral dysfunction. Methods: Serial measurements of the EC 2-AG pre- and postoperatively (PO), and on PO days 1, 2, and 3 after surgery were done in 106 patients. ACD was defined as an inadequate neurologic response in an awaken patient at the first attempt of postoperative extubation requiring re-sedation and prolonged ventilation. In extubated patients, delirium was diagnosed according to DSM-IV criteria. Results: Post-op ACD/Delirium was seen in 13 patients (12.3%). Patients who developed ACD/Delirium had significantly lower pre-op 2-AG (3.8 vs. 11.3ng/ml, p=0.04) plasma concentrations as well as higher postoperative proinflammatory interleukin-6 (IL-6) levels on PODs 1 to 3 when compared to patients without ACD (2378 vs. 81 pg/ml, p<0.05). The preoperative use of statins (56 patients) was associated with significantly higher pre-op 2-AG levels (p=0.02). Patients receiving statins had lower IL-6 levels postoperatively (p<0.01). A direct effect of statins on the incidence of ACD/Delirium was not observed (p=0.22). Conclusions: These data support the hypothesis that the antiinflammatory and neuroprotective effects of the EC 2-AG are modulated by the preoperative use of statins.

Optimal dose of aprotinin for neuroprotection and renal function in a piglet survival model

The efficacy of aprotinin in reducing blood loss after cardiopulmonary bypass is well established, although its neuroprotective potential is less well known. Furthermore, there is controversy regarding optimal dosing and possible renal complications. Fifty-four piglets were randomized to one of 3 cardiopulmonary bypass groups designed to carry the risk of postoperative cerebral and renal dysfunction: circulatory arrest at 25 degrees C and ultra-low flow bypass (10 mL x kg(-1) x min(-1)) at either 25 degrees C or 34 degrees C. Animals were randomized to the following groups: control (no aprotinin), low dose (30,000 KIU/kg into prime only), standard full dose (30,000 KIU/kg bolus administered intravenously into prime plus 10,000 KIU/kg infusion), and double full dose. The tissue oxygenation index was monitored by means of near-infrared spectroscopy. Neurologic functional and histologic scores and creatinine and blood urea nitrogen values were outcomes of interest. Aprotinin significantly improved neurologic scores on postoperative day 1 after ultra-low-flow bypass at 25 degrees C or 34 degrees C (P < .01) but not after hypothermic circulatory arrest (P = .57). Linear regression indicated a strong dose-response relationship, with higher aprotinin doses having the best neurologic scores. During low-flow bypass, a higher tissue oxygenation index was correlated with a higher aprotinin dose (P < .05). Aprotinin dose had no significant effect on creatinine or blood urea nitrogen values on day 1. Low body weight was the only predictor of high blood urea nitrogen values (r = -0.39, P < .01). Aprotinin significantly improves neurologic recovery without compromising renal function in the young piglet.

Aprotinin protects the cerebral microcirculation during cardiopulmonary bypass

We have previously reported that administration of aprotinin at a single dose protects the cerebral microcirculation. The current study was designed to identify the optimal dose for protecting the cerebral microcirculation with assessment of neurological and behavioral recovery as well as renal function after circulatory arrest and ultra-low-flow bypass. Twenty-four piglets were randomly assigned to three bypass groups at risk for postoperative cerebral and renal dysfunction. Cerebral microcirculation was assessed by intravital microscopy. Rhodamine-stained leukocytes were observed for adhesion and rolling. Animals were randomized to one of four aprotinin doses. Neurological deficit score, histological score, creatinine and blood urea nitrogen were analyzed, both independently for this study as well as in combination with 50 animals who were studied with the same protocol and near-infrared spectroscopy. There was a dose-dependent relationship, resulting in fewer activated rolling leukocytes with a higher aprotinin dose. Aprotinin dose was an independent predictor of more rapid recovery of neurological and behavioral outcome. We present a linear regression model where aprotinin dose predicts neurological score. Aprotinin had no impact on renal function. Aprotinin reduces cerebral leukocyte activation and accelerates neurologic recovery in a dose-dependent fashion. Aprotinin has no measurable impact on standard indices of renal function in young piglets. The current lack of availability of aprotinin is a serious disadvantage for pediatric patients undergoing cardiopulmonary bypass.

The use of neurocognitive tests in evaluating the outcome of cardiac surgery: Some methodologic considerations

NEUROCOGNITIVE TESTING has an established role in assessing cardiac surgery outcome, particularly when extracorporeal perfusion (cardiopulmonary bypass) procedures are employed. Such assessments have been in regular use since the 1960s and, through highlighting the presence of possible postoperative cerebral dysfunction, have contributed to the improvement of surgical techniques over this period.1,2 Continued use of neurocognitive tests is assured, given that they directly measure the concerns of patients and their families—changes in the patients' ability to think, learn, memorize, carry out a range of activities of daily living.

Stroke after coronary artery operation: incidence, correlates, outcome, and cost

Background. Stroke is a major complication of coronary operation, with reported rates of postoperative cerebral dysfunction ranging from 0.4% to 13.8%. In this report, the incidence, correlates, outcomes, and costs of stroke in coronary operation were evaluated at Emory University between 1988 and 1996.Methods. Data were entered prospectively into a dedicated computerized database at Emory University and analyzed retrospectively. Univariate and multivariate analyses were utilized where appropriate.Results. Data from 10,860 patients undergoing primary coronary operation between 1988 and 1996 were analyzed. There were 250 patients not entered into the database. Stroke occurred in 244 (2.2%). Univariate predictors of stroke (p < 0.05) included age, female gender, hypertension, diabetes, prior stroke, prior transient ischemic attack (TIA), and carotid bruits. Multivariate correlates included age (odds ratio 1.07) previous TIA (odds ratio 2.2), and carotid bruits (odds ratio 1.9), although the area under the Receiver Operating Characteristics (ROC) curve was only 0.69, suggesting limited ability to predict stroke. One and 5 year survival rates were 64% and 44% with stroke, and 94% and 81% without stroke, respectively. Among the stroke group, 23% of the patient population died before hospital discharge. The stroke group had a significantly longer length of hospital stay, as well as higher costs.Conclusions. Stroke is a devastating complication of coronary operation, significantly increasing morbidity, mortality, and cost. Three independent variables were identified for predicting stroke, including age, previous TIA, and carotid bruits. Patients should be carefully screened for cerebrovascular disease to help prevent stroke and its associated morbidity.

A randomized, blinded trial of the antioxidant pegorgotein: No reduction in neuropsychological deficits, inotropic drug support, or myocardial ischemia after coronary artery bypass surgery

Objective: To determine whether patients receiving pegorgotein preoperatively would be less likely than patients receiving placebo to demonstrate postoperative cerebral or myocardial dysfunction and thus would be less likely to (1) demonstrate a decline in neuropsychologic testing after cardiopulmonary bypass, (2) receive inotropic drug support, or (3) demonstrate electrocardiographic signs of ischemia or infarction. Design: Prospective, randomized, blinded clinical trial. Setting: University teaching hospital and clinics. Participants: Sixty-seven patients with normal left ventricular function undergoing elective, primary coronary artery bypass surgery. Interventions: Six to 18 hours before aortic cross-clamping, patients received a single dose of placebo ( n = 22); pegorgotein, 2,000 IU/kg intravenously ( n = 23); or pegorgotein, 5,000 IU/kg intravenously ( n = 22). Measurements and Main Results: Patients in the three groups were similar; the mean ages were 65, 66, and 67 years, and there were seven, eight, and seven women in the placebo; pegorgotein, 2,000 IU/kg; and pegorgotein, 5,000 IU/kg groups. Fifty-one of 67 patients demonstrated neuropsychologic deficit 5 to 7 days postoperatively ( n = 17, 19, and 15 for placebo, 2,000 IU/kg, and 5,000 IU/kg; p = NS). Median duration of cardiopulmonary bypass was longer in patients with two or more deficits at 4 to 6 weeks than in those with fewer than two deficits (121 v 98 minutes; p = 0.04). No patient demonstrated a perioperative stroke. Twenty-seven patients required inotropic drug support after cardiopulmonary bypass ( n = 8, 11, and 8 for placebo, 2,000 IU/kg, and 5,000 IU/kg; p = NS). Inotropic drug support was associated with history of angina ( p = 0.01) and increasing weight ( p = 0.03). Nine patients demonstrated early postoperative ischemia or infarction ( n = 1, 7, and 1 for placebo, 2,000 IU/kg, and 5,000 IU/kg; p = 0.07). Conclusions: This study showed no positive influence of pegorgotein on the incidence of any of the findings and showed a trend toward an increased incidence of myocardial ischemia or infarction.

Cerebral physiology in paediatric cardiopulmonary bypass.

To analyze studies of neurological injury after open-heart surgery in infants and children and to discuss the effects of cardiopulmonary bypass, hypothermia and deep hypothermic circulatory arrest on cerebral blood flow, cerebral metabolism and brain temperature. Articles were obtained from the databases, Current Science and Medline, from 1966 to present. Search terms include cardiopulmonary bypass (CPB), hypothermia, cerebral blood flow (CBF), cerebral metabolism and brain temperature. Information and abstracts obtained from meetings on the topic of brain and cardiac surgery helped complete the collection of information. In adults the incidence of neurological morbidity is between 7 to 87% with stroke in about 2-5%, whereas the incidence of neurological morbidity increases to 30% in infants and children undergoing cardiopulmonary bypass. Besides the medical condition of the patient, postoperative cerebral dysfunction and neuronal ischaemia associated with cardiac surgery in infants and small children are a combination of intraoperative factors. Deep hypothermic circulatory arrest impairs CBF and cerebral metabolism even after termination of CPB. Inadequate and/or non-homogenous cooling of the brain before circulatory arrest, as well as excessive rewarming of the brain during reperfusion are also major contributory factors. Newer strategies, including the use of low-flow CPB, pulsatile CPB, pH-stat acid-base management and a cold reperfusion, are being explored to ensure better cerebral protection. Advances in monitoring technology and better understanding of the relationship of cerebral blood flow and metabolism during the different modalities of cardiopulmonary bypass management will help in the medical and anaesthetic development of strategies to improve neurological and developmental outcomes.

Con: During cardiopulmonary bypass for elective coronary artery bypass grafting, perfusion pressure should not routinely be greater than 70 mmHg

Con: During cardiopulmonary bypass for elective coronary artery bypass grafting, perfusion pressure should not routinely be greater than 70 mmHg