International Study Of Postoperative Cognitive Dysfunction Research Articles

Association between cerebrospinal fluid biomarkers of neuronal injury or amyloidosis and cognitive decline after major surgery

BackgroundPostoperative neurocognitive decline is a frequent complication in adult patients undergoing major surgery with increased risk for morbidity and mortality. The mechanisms behind cognitive decline after anaesthesia and surgery are not known. We studied the association between CSF and blood biomarkers of neuronal injury or brain amyloidosis and long-term changes in neurocognitive function. MethodsIn patients undergoing major orthopaedic surgery (knee or hip replacement), blood and CSF samples were obtained before surgery and then at 4, 8, 24, 32, and 48 h after skin incision through an indwelling spinal catheter. CSF and blood concentrations of total tau (T-tau), neurofilament light, neurone-specific enolase and amyloid β (Aβ1-42) were measured. Neurocognitive function was assessed using the International Study of Postoperative Cognitive Dysfunction (ISPOCD) test battery 1–2 weeks before surgery, at discharge from the hospital (2–5 days after surgery), and at 3 months after surgery. ResultsCSF and blood concentrations of T-tau, neurone-specific enolase, and Aβ1-42 increased after surgery. A similar increase in serum neurofilament light was seen with no overall changes in CSF concentrations. There were no differences between patients having a poor or good late postoperative neurocognitive outcome with respect to these biomarkers of neuronal injury and Aβ1-42. ConclusionsThe findings of the present explorative study showed that major orthopaedic surgery causes a release of CSF markers of neural injury and brain amyloidosis, suggesting neuronal damage or stress. We were unable to detect an association between the magnitude of biomarker changes and long-term postoperative neurocognitive dysfunction.

Ratio of β-amyloid protein (Aβ) and Tau predicts the postoperative cognitive dysfunction on patients undergoing total hip/knee replacement surgery.

β-amyloid (Aβ) and Tau proteins are biomarkers of Alzheimer's disease neuropathogenesis. We hypothesized that they are also potential biomarkers for postoperative cognitive dysfunction (POCD). The present study was designed to evaluate the use of the Aβ-42/Tau ratio for the diagnosis of POCD in patients undergoing hip/knee replacement surgery. A total of 80 patients who underwent total hip/knee replacement surgery were grouped into POCD or non-POCD patients at 7 days, 1 and 3 months after surgery, according to a z-score recommended by the international study of POCD. Cerebrospinal fluid samples were collected prior to surgery and the concentration of Aβ-42 and Tau protein were detected. The ratio of Aβ-42/Tau was compared between the two groups at different time points. The patients completed the whole battery of neuropsychological tests following surgery. The POCD occurrence rates at 7 days, 1 and 3 months were 40, 25 and 15%, respectively. The Aβ-42/Tau ratios were much lower in the POCD group than those in the non-POCD group at 7 days (1.7±0.4 vs. 2.6±0.3), 1 month (1.6±0.5 vs. 2.4±0.4), and 3 months (1.6±0.4 vs. 2.5±0.4). The sensitivity and specificity for diagnosis of POCD as indicated by the ratios, at the three time points, were 91.7 vs. 81.2%, 86.7 vs. 70%, and 88 vs. 75.5%, respectively. The results show the incidence of POCD of patients aged at least 65 years who have undergone hip or knee fracture surgery gradually decrease as more patients recover. However, the Aβ-42/Tau ratio can be used in forecasting the occurrence of POCD elderly patients.

Postoperative Cognitive Dysfunction in Elderly Patients: A Frequent Complication

also weeks or months after surgery and not always recognized in the early postoperative period because its recognition need the employment of neurological and psychological tests [2]. POCD must be distinguished by delirium that is present early in postoperative period and is characterized by an acute change of attention and thought. It can be diagnosed utilizing confusion assessment method (CAM) [3]. The reported incidence of POCD varies from 7 to 71% at seven-eight postoperative days and 6 to 56% at an interval of 42-84 days [4]. The exact incidence is not known because POCD is not always recognized in the postoperative period since diagnosis requires many sensitive neuropsychological tests and these tests can be difficult to administer in clinical trials in which the sample of the patients may be elevated. Tests are different for the cognitive domain that they study. The working group ISPOCD (International Study of Postoperative Cognitive Dysfunction) has conducted several studies in this field and has also created some recommendations. It was found that in the diagnosis of POCD it should be used a battery of tests to investigate the different domains involved in cognitive functions such as memory, attention, speed motion sensory and flexibility cognitive; moreover, these tests should be sensitive to allow the diagnosis of mild deficits such as those characteristic of POCD. The assessment of cognitive function in the postoperative period is based on the results of pre-and postoperative tests. Often, to correct the “practice effect” that is often present when performing neuropsychological tests repeated over time it is used a control group [5].

Methods and madness: agitation, delirium, and postoperative cognitive dysfunction

Over the past decade, disorders of cognition in adult surgical patients have attracted the attention of perioperative physicians. As our surgical population ages and lengths of hospital stay decrease, postoperative cognitive deficits present a barrier to efficient discharge and return to function in the community. Physicians are aware that treatment of delirium adds $2,500 US to hospital stays of patients [ 65 yr of age, costing Medicare approximately $6.9 billion US annually. Similarly, we know that patients with postoperative cognitive dysfunction (POCD) one week following surgery are more likely to leave employment, while those with POCD persisting three months postoperatively suffer an increased risk of mortality in the subsequent five years. In this month’s issue of the Journal, Yu et al. present an observational cohort study of 2,000 patients undergoing general anesthesia. Their study results indicate that [ 20% of adult subjects experienced postanesthetic agitation. Delirium, POCD, agitation—the variety of cognitive disorders studied in the perioperative period can be...well...rather confusing. Often the terms are defined poorly and sometimes they are used interchangeably. Is agitation in the postanesthesia care unit synonymous with delirium? Is emergence agitation, like delirium, associated with significant adverse outcomes? While emergence agitation may not be representative of normal cognition, is it POCD? What is the busy clinician to make of all this? Perhaps a good beginning would be to takee the advice of management expert, W. Edwards Deming, and describe the process under discussion. Only one of the conditions mentioned in the preceding paragraph is a diagnosable psychiatric disorder. The Diagnostic and Statistical Manual of Mental Disorders defines delirium as a transient, fluctuating disturbance of consciousness, attention, cognition, and perception. The Confusion Assessment Method (CAM) operationalizes the diagnosis of delirium using four clinical features: 1) acute onset and fluctuating course; 2) inattention; 3) disorganized thinking; and 4) altered level of consciousness. Diagnosis is based on the presence of features 1 and 2 plus one of either 3 or 4. The CAM has been used extensively, and its sensitivity and specificity both exceed 90%. On the other hand, POCD is a more subtle condition and more difficult to quantify. While inherently challenging, POCD research has been hampered further by the large number of cognitive tests employed and the widely disparate definitions of an abnormal test result. An operating definition of POCD has emerged based on a decade of research by the International Study of Postoperative Cognitive Dysfunction (ISPOCD). The ISPOCD research group employs a battery of four individual neuropsychometric tests given before and after surgery and standardizes interval changes in test scores using data from a non-surgical control group. While the deficits in attention, concentration, executive function, verbal memory, visuospatial abstraction, and psychomotor speed are both real and quantifiable, POCD as a disorder is

Evaluative effect of basic cognitive capability test for postoperative cognitive dysfunction in elderly patients

Objective To compare basic cognitive capability teat (version 2.0) with the method recommended by ISPOCD (international study of postoperative cognitive dysfunction) on the evaluation of postoperative cognitive dysfunction (POCD) in elderly patients, and study the correlation of two different methods. Methods Two neuropsychological tests were performed preoperatively, and postoperatively on Day 7 and 3 months upon 131 elderly patients undergoing elective major non-cardiac surgery and 30 healthy elderly volunteers that were set as a control group. One was Basic Cognitive Capability Test (Method A), including digit copying (A1), mental arithmetic (A3), et al. However, The other was recommended by ISPOCD (Method B), including trail making test (B1), digit symbol sub-test (B2), et al. Z score was used to analyze the data. POCD was defined as Z score ≥2. Results (1) 120 out of 131 patients had completed the tests on Day 7 postoperatively, and then 67 among them had finished the tests 3 months postoperatively. (2) The incidence rate of POCD on Day 7 was (12.5% and 10.8%,P>0.05); and at 3 months was (5.97% and 7.46%, P >0.05). (3) Two methods were consistent for evaluation of POCD on Day 7 and 3 months postoperatively. Kappa were 0. 758 and 0.881, P<0.05. (4) Both on Day 7 and 3 months, the combined Z score of Method A and Method B had significant correlation, r =0.316 and 0.302 ,P < 0.05. (5) As for speed of recognition, digit copying (A1) vs. trail making test (B1) had significant correlation, r=0.517, P<0.05. For ability of study and performance, mental arithmetic (A3) vs. digit symbol subtest (B2) had significant correlation, r = 0. 52, P < 0. 05. Conclusion Basic cognitive capability test was consistent with tests recommended by ISPOCD for evaluation of POCD. Basic cognitive capability test using computer was more objective, accurate and beneficial for clinical practice. Key words: POCD; Basic cognitive capability test; Neuropsychological tests

Central Nervous System Dysfunction after Noncardiac Surgery and Anesthesia in the Elderly

Central Nervous System Dysfunction after Noncardiac Surgery and Anesthesia in the Elderly