ORCID Profile
0000-0002-9051-7913
Current Organisations
Weill Cornell Medicine
,
St Vincent's Hospital Melbourne
,
University of Melbourne
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Publisher: Cambridge University Press (CUP)
Date: 02-11-2012
DOI: 10.1017/S1041610212001792
Abstract: It has long been observed that some patients suffer a significant cognitive impact following anesthesia and surgery. This should not be surprising when considering that not only is the target organ for general anesthetic agents the brain itself but also that the process of anesthesia is a form of deep, pharmacologically induced coma rather than “sleep.” The expectation that such a process should be fully reversible with transient neurophysiological effects contradicts our experience with repeated abuse of other central nervous system depressants such as glue, petrol, and alcohol. Of great concern is that, while approximately 10% of populations in developed countries undergo anesthesia and surgery of some form each year, the proportion of the elderly making up this group is much greater. In addition, it is the elderly who are potentially at a greater risk of cognitive impairment following such procedures because many have decreased cognitive reserve, either due to pre-existing mild cognitive impairment (MCI) or frank dementia, which may be diagnosed or unknown. The impact of anesthesia on these in iduals is poorly understood, as are the implications of the emerging laboratory data that suggest an effect of anesthetic agents on the pathological processes of Alzheimer's Disease (AD) itself.
Publisher: Elsevier BV
Date: 08-2023
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2007
DOI: 10.1213/01.ANE.0000263285.03361.3A
Abstract: An accurate assessment of the prevalence of cognitive impairment in patients scheduled for coronary artery bypass graft (CABG) surgery is necessary if valid assumptions regarding cognitive change are to be made. Such an assessment requires the use of a healthy control group free of cardiovascular disease. In a retrospective observational study, 349 patients scheduled for CABG surgery underwent neuropsychological testing. We compared the results with those from a group of 170 healthy controls without cardiovascular disease and containing more female patients who were matched for age and IQ score. Cognitive impairment was defined as test scores > or =2 sd less than the controls on two or more of the seven tests. The CABG surgery patients performed significantly worse than the control group on all tests except the Grooved Pegboard test (nondominant). When analyzed by group, performance on the verbal learning test was the most impaired. Cognitive impairment was present in 122 (35%) of CABG surgery patients before their procedure. Prior myocardial infarction, age, and IQ were independent predictors of cognitive impairment. Cognitive impairment is prevalent in patients presenting for CABG surgery. Impaired cognition before surgery must be considered when assessing the effects of CABG surgery on cognitive performance.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2010
Publisher: American Medical Association (AMA)
Date: 03-2002
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2011
Publisher: Elsevier BV
Date: 04-2010
DOI: 10.1016/J.ATHORACSUR.2009.11.056
Abstract: The relationship of aortic atheroma to postoperative cognitive dysfunction (POCD), a common complication of coronary artery bypass graft surgery, has not been resolved. We undertook assessment of aortic atheroma using intraoperative ultrasonography and related the degree of aortic atheroma to POCD. Aortic atheroma was assessed using intraoperative transesophageal and epiaortic echocardiography in 311 patients who underwent coronary artery bypass graft surgery. Atheroma was graded from 0 (normal or minimal) to 3 (mobile or rough) in each of four quadrants of the proximal ascending to proximal descending thoracic aorta. Atheroma burden was defined as the atheroma score ided by the total possible score for that patient. Patients also completed a neuropsychological battery consisting of eight tests taken the week before surgery and at 1 week and 3 and 12 months afterward. Decreased cognitive function for each test was defined as an in idual decrease of at least 1 standard deviation of the group baseline mean for that test, and POCD was defined as a decrease in two or more tests. The atheroma burden (%) was greater in the patients with POCD. The difference was greatest at 1 week (10.4+/-14.7 versus 4.4+/-9.0, p=0.0002) and diminished progressively at 3 months (8.9+/-14.1 versus 5.4+/-10.1, p=0.06) and 12 months (6.6+/-12.0 versus 5.6+/-10.2, p=0.56). Multivariable analysis showed that atheroma burden strongly predicted POCD at 1 week. Aortic atheroma burden predicts POCD at 1 week but has less impact on POCD as time progresses. Atheroma burden is highly correlated with age and may be a good predictor of early POCD.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2006
DOI: 10.1097/00000542-200606000-00007
Abstract: Postoperative cognitive dysfunction (POCD) after coronary artery bypass graft surgery is a common complication for which, despite many clinical investigations, no definitive etiology has been found. The current use of both high- and low-dose fentanyl as anesthetic techniques allowed us to investigate the effect of fentanyl on the incidence of POCD. Three hundred fifty patients scheduled to undergo elective coronary artery bypass graft surgery were randomized to receive either high-dose fentanyl (50 microg/kg) or low-dose fentanyl (10 mug/kg) as the basis of the anesthetic. All patients underwent neuropsychological testing before surgery and at 1 week, 3 months, and 12 months after surgery. One hundred sixty-eight patients in the low-dose group and 158 patients in the high-dose group were included in the final analysis. Neuropsychological testing was performed on 88%, 93%, and 92% of patients at 1 week, 3 months, and 12 months, respectively. There was no difference between group mean scores at any of the three testing times. Analysis of in idual patients by the 20% rule did not detect any differences between groups. The one SD rule, which has fewer false-positive results, detected significantly more patients with POCD in the low-dose group than in the high-dose group at 1 week (23.6% vs. 13.7% P = 0.03) but not at the other testing times. Patients with POCD spent an average of 1.2 days longer in the hospital than those without POCD (P = 0.021). High-dose fentanyl is not associated with a difference in the incidence of POCD at 3 or 12 months after surgery. Low-dose fentanyl leads to shorter postoperative ventilation times and may be associated with a greater incidence of POCD 1 week after surgery. Early POCD is associated with an increased duration of stay in the hospital.
Publisher: Wiley
Date: 12-1989
DOI: 10.1111/J.1440-1681.1989.TB02405.X
Abstract: 1. A biventricular, low-output congestive cardiomyopathy was induced in 19 rabbits by administering adriamycin (16 mg/kg). The effects of alpha-rat atrial natriuretic peptide (ANP) infused at 0.1, 0.2 and 0.4 micrograms/kg per min, were then examined in terms of (i) central haemodynamics (ii) regional blood flow (iii) renal function and (iv) plasma norepinephrine and plasma renin. 2. In this dose range, ANP produced progressive and significant falls in stroke volume, cardiac output and mean arterial pressure, owing to a fall in venous return. The heart rate response to this was blunted. 3. Using radiolabelled microspheres, significant falls in the perfusion of cutaneous, gastrointestinal and musculoskeletal tissues were observed, due to reduced vascular conductances in these beds. These changes were accompanied by activation of the sympathetic nervous system as evidenced by a progressive rise in plasma norepinephrine. A significant increase in plasma renin was only observed with the highest infusion of ANP. 4. Renal blood flow was maintained in the face of a falling mean arterial pressure and cardiac output, but diuretic and natriuretic effects were absent. 5. It was concluded that the dominant influence of ANP infusion in this model of heart failure appeared to be a reduction in cardiac preload with detrimental overall haemodynamic consequences.
Publisher: Elsevier BV
Date: 08-2013
DOI: 10.1016/J.JACC.2013.03.073
Abstract: This study sought to determine whether post-operative neurocognitive dysfunction (POCD) occurs after ablation for atrial fibrillation (AF). Ablation for AF is a highly effective strategy however, the risk of transient ischemic attack and stroke is approximately 0.5% to 1%. In addition, magnetic resonance imaging studies report a 7% to 14% prevalence of silent cerebral infarction. Whether cerebral ischemia results in POCD after ablation for AF is not well established. The study included 150 patients 60 patients undergoing ablation for paroxysmal atrial fibrillation (PAF), 30 patients undergoing ablation for persistent atrial fibrillation (PeAF), and 30 patients undergoing ablation for supraventricular tachycardia (SVT) were compared with a matched nonoperative control group of patients with AF awaiting radiofrequency ablation (n = 30). Eight neuropsychological tests were administered at baseline and at 2 days and 90 days post-operatively. The tests were administered at the same time points to the nonoperative control group. The reliable change index was used to calculate POCD. The prevalences of POCD at day 2 post-procedure were 28% in patients with PAF, 27% in patients with PeAF, 13% in patients with SVT, and 0% in control patients with AF (p = 0.007). At day 90, the prevalences of POCD were 13% in patients with PAF, 20% in patients with PeAF, 3% in patients with SVT, and 0% in control patients with AF (p = 0.03). When analyzing the 3 procedural groups together, 29 of 120 patients (24%) manifested POCD at day 2 and 15 of 120 patients (13%) at day 90 post-procedure (p = 0.029). On univariate analysis, increasing left atrial access time was associated with POCD at day 2 (p = 0.04) and day 90 (p = 0.03). Ablation for AF is associated with a 13% to 20% prevalence of POCD in patients with AF at long-term follow-up. These results were seen in a patient population with predominant CHADS2 (Congestive heart failure, Hypertension, Age ≥75 years, Diabetes mellitus, previous Stroke/transient ischemic attack) scores of 0 to 1, representing the majority of patients undergoing ablation for AF. The long-term implications of these subtle changes require further study.
Publisher: Elsevier BV
Date: 10-2023
Publisher: Elsevier BV
Date: 10-1997
DOI: 10.1016/S0306-4522(97)00232-7
Abstract: Immunohistochemical detection of the protein, Fos, was used to identify neurons in the brain activated following a volume load. The plasma expanders, Haemaccel and 6% dextran, were infused intravenously in conscious rabbits for 60 min. Compared to control animals both stimuli significantly increased right atrial pressure but had no effect on blood pressure. Heart rate was significantly elevated with dextran only. Volume expansion with Haemaccel also reduced renal sympathetic nerve activity by about 50% from the pre-infusion resting level. Ninety minutes after the start of the infusion, the rabbits were perfusion fixed and the distribution of Fos-positive cell nuclei was examined. Following Haemaccel infusion there were significant increases in the number of Fos-positive cell nuclei in the organum vasculosum of the lamina terminalis, parvocellular paraventricular nucleus and in specific rostrocaudal levels of the nucleus tractus solitarius and ventrolateral medulla. Following dextran similar effects were observed in the medulla but Fos-positive cell nuclei were not significantly elevated above controls in the forebrain. After Haemaccel or dextran areas such as the supraoptic nucleus, the magnocellular paraventricular nucleus, the bed nucleus of the stria terminalis, diagonal band of Broca and amygdala either did not produce Fos or were not consistently different from the control group. The results suggest that specific brain regions, that are known to be important in cardiovascular control, are activated by a volume load. These areas are likely to play an important role in the reflex responses initiated by that particular stimulus.
Publisher: Elsevier BV
Date: 07-2014
Publisher: Oxford University Press (OUP)
Date: 08-2006
DOI: 10.1016/J.ACN.2006.05.004
Abstract: The reliable change index (RCI) expresses change relative to its associated error, and is useful in the identification of post-operative cognitive dysfunction (POCD). This paper examines four common RCIs that each account for error in different ways. Three rules incorporate a constant correction for practice effects and are contrasted with the standard RCI that had no correction for practice. These rules are applied to 160 patients undergoing coronary artery bypass graft (CABG) surgery who completed neuropsychological assessments preoperatively and 1 week post-operatively using error and reliability data from a comparable healthy non-surgical control group. The rules all identify POCD in a similar proportion of patients, but the use of the within subject standard deviation, expressing the effects of random error, as an error estimate is a theoretically appropriate denominator when a constant error correction, removing the effects of systematic error, is deducted from the numerator in a RCI.
Publisher: Elsevier BV
Date: 02-1997
DOI: 10.1016/S0002-8703(97)70213-8
Abstract: Head-up tilt provokes vasodepressor syncope in patients with this disorder but may also cause fainting in unaffected subjects. The aims of this study were to examine autonomic function and sequential changes in heart rate variability and plasma catecholamines during graded head-up tilt in patients with vasodepressor syncope compared with healthy subjects. Studies were performed in 10 patients and 15 control subjects. Eight negative controls completed the study presyncope or syncope developed in seven positive controls and all 10 patients. The negative control group showed a progressive increase in mid-frequency from the supine position to end tilt. Patients and positive controls showed significant and similar falls in mid-frequency in the presyncope period. The rise in plasma norepinephrine was blunted in patients and positive controls, whereas plasma epinephrine increased more in these groups compared with the negative control group. In conclusion, the patterns of heart rate variability and catecholamine changes could not be distinguished in patients and positive control subjects.
Publisher: Elsevier BV
Date: 06-2004
DOI: 10.1093/BJA/AEH157
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-1991
DOI: 10.1213/00000539-199110000-00013
Abstract: Circulatory responses to isoflurane and halothane anesthesia were studied in eight rabbits with biventricular cardiomyopathy induced by doxorubicin (Adriamycin, 14 mg/kg IV over 7 wk) and in eight controls (saline injections). In preliminary operations pulsed-Doppler flow probes were placed on the ascending aorta, left renal artery, and lower abdominal aorta. Each group was studied after 4, 6, and 7 wk of treatment. The development of congestive heart failure (CHF) was associated with decreases in mean arterial pressure and cardiac output (CO) of 14% and 16%, respectively, (P less than 0.05) and an increase in heart rate. In controls, each anesthetic agent produced dose-related decreases in mean arterial pressure and increases in heart rate, but not significant changes in CO. Renal blood flow was reduced to a similar degree by 1.3 MAC halothane (24% decrease) and 1.3 MAC isoflurane (21% decrease) hindlimb blood flow was reduced only by halothane. As CHF developed there was an attenuation of the heart rate response to anesthesia. Halothane, but not isoflurane, significantly reduced CO in more advanced stages of CHF. The changes in renal blood flow and hindlimb blood flow with each anesthetic in the CHF group were similar to those observed in controls and did not vary with week of treatment. Administration of the angiotensin-converting enzyme inhibitor enalaprilat (0.2 mg/kg IV) reversed the CO and renal blood flow effects of halothane except after 7 wk of treatment in the CHF group, when the combination of halothane and enalaprilat resulted in severe circulatory depression.
Publisher: Wiley
Date: 03-1990
DOI: 10.1111/J.1440-1681.1990.TB01310.X
Abstract: 1. The effects of graded treadmill exercise on renal blood flow (RBF) were examined in seven rabbits, in which congestive heart failure (CHF) was produced by the administration of doxorubicin, 1 mg/kg, twice weekly for 8 weeks, and in seven controls. A third group of five rabbits underwent doxorubicin treatment with the addition of surgical section of the left renal sympathetic nerve. 2. During submaximal exercise, there was a small reduction in RBF in controls, which was greatly exaggerated in CHF. 3. In both control and heart failure rabbits, there was a precipitous fall in RBF as exercise fatigue developed. 4. Renal sympathectomy ablated these changes in RBF during exercise. 5. It is concluded that in heart failure there is an exaggerated, sympathetically mediated, ersion of blood flow away from the kidney. The onset of exercise fatigue in both normal and heart failure rabbits is accompanied by a marked intensification of this process.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2011
DOI: 10.1097/ALN.0B013E31821B1AAB
Abstract: The prevalence of preexisting cognitive impairment (PreCI) is documented before cardiac surgery, but there is less information before noncardiac surgery. In addition, the prevalence of mild cognitive impairment, defined by different cognitive criteria and subjective complaints, and which may progress to Alzheimer disease, is unknown in these subjects. Because anesthesia and surgery have been implicated in Alzheimer disease pathology, we prospectively measured PreCI and mild cognitive impairment in subjects scheduled for total hip joint replacement surgery in an observational study. One hundred fifty-two subjects 60 y of age and older who were scheduled for total hip joint replacement surgery underwent assessment, including neuropsychologic testing, 1 week before surgery. Test results were compared with published norms. PreCI was defined as impairment in two or more of seven cognitive tests, for which impairment in an in idual test was defined as ≥ 2 SD below norms for that test. Amnestic mild cognitive impairment (aMCI) was defined as impairment ≥1.5 SD below norms for results of the immediate and/or delayed Auditory Verbal Learning Test plus a subjective complaint. Subjects performed worse compared with normative data on five of seven neuropsychologic tests. Thirty (20% [95% CI, 13-26%]) subjects were classified as having PreCI. Thirty-four (22% [95% CI, 16-29%]) were classified as having aMCI. Ten (7%) subjects were classified as having both PreCI and aMCI, representing 33% of the 30 subjects with PreCI. The prevalence of aMCI in subjects scheduled for total hip joint replacement surgery is similar to that in the general community. PreCI and aMCI tend to identify different subjects. Because aMCI is known to progress to Alzheimer disease, future studies that track cognition before and after anesthesia and surgery should document the presence or absence of aMCI so that the rate of conversion to Alzheimer disease after anesthesia and surgery can be compared with the rate in the nonsurgical population.
Publisher: Elsevier BV
Date: 09-2008
DOI: 10.1016/J.ATHORACSUR.2008.04.085
Abstract: The plasma protein apolipoprotein E (APOE) is a risk factor for degenerative cognitive decline manifested by mild cognitive impairment and later by Alzheimer's disease. Patients undergoing coronary artery bypass grafting (CABG) are known to have a high prevalence of preexisting cognitive impairment and postoperative cognitive dysfunction. Because both mild cognitive impairment and Alzheimer's disease generally occur in elderly in iduals, the age group that commonly present for CABG, we investigated if the APOE epsilon4 allele was associated with patients manifesting preexisting cognitive impairment and postoperative cognitive dysfunction. The DNA of 282 patients who had undergone neuropsychologic testing before and 3 and 12 months after CABG was analyzed for APOE genotype. Patients were classified as having preexisting cognitive impairment if cognitive function was decreased in two or more tests compared with a healthy control group. Postoperative cognitive dysfunction was defined as a decrease in two or more tests compared with the group mean baseline score. The APOE epsilon4 allele was found in 83 (29.4%) patients. Although preexisting cognitive impairment was present in 105 (37.2%) and postoperative cognitive dysfunction in 33 (12%) and 31 (11%) at 3 and 12 months postoperatively, there was no relationship with the presence of the APOE epsilon4 allele or any of the six genotypes. Preexisting cognitive impairment and postoperative cognitive dysfunction are not associated with APOE epsilon4 genotype, suggesting that cognitive impairment both before and after CABG may not be associated with degenerative cognitive decline.
Publisher: Elsevier BV
Date: 11-2014
DOI: 10.1093/BJA/AEU163
Abstract: Since general anaesthesia invariably accompanies surgery, the contribution of each to the development of postoperative cognitive dysfunction (POCD) has been difficult to identify. A prospective randomized controlled trial was undertaken in elderly patients undergoing extracorporeal shock wave lithotripsy (ESWL). Between 2005 and 2011, 2706 in iduals were screened to recruit 100 eligible patients. Patients were randomly assigned to receive general or spinal anaesthesia alone. A battery of eight neuropsychological tests was administered before operation and at 7 days and 3 months after operation. The reliable change index was used to calculate the incidence of POCD. Intention-to-treat analysis was used to compare rates of POCD. Futility analysis led to stopping of the trial after recruitment of 100 patients. Fifty patients were randomly assigned to general anaesthesia, and 48 patients to spinal anaesthesia without sedation or postoperative opioids. At 3 months, POCD was detected in 6.8% [95% confidence interval (CI): 1.4-18.7%] of patients in the general anaesthesia group and 19.6% (95% CI: 9.4-33.9%) in the spinal group (P=0.07). At 7 days after operation, the incidence of POCD was 4.1% (95% CI: 0.5-14%) in the general anaesthesia group and 11.9% (95% CI: 4.0-26.6%) in the spinal group (P=0.16). We found no significant difference in the rates of POCD when comparing general anaesthesia with spinal anaesthesia, suggesting that the surgical or procedural process itself may contribute to the development of POCD. Australian Clinical Trials Registry number ACTRN12605000150640.
Publisher: Elsevier BV
Date: 11-2009
DOI: 10.1016/J.ATHORACSUR.2009.07.003
Abstract: Decreased cognitive function associated with coronary artery bypass graft surgery is common. These deficits may be similar to the cognitive dysfunction seen in the spectrum of mild cognitive impairment to Alzheimer's disease, which are believed to result from the accumulation of amyloid beta (Abeta) peptide in the brain. We measured cognition both before and after coronary artery bypass graft surgery and assayed Abeta levels to investigate whether the cognitive dysfunction of cardiac surgery was associated with Abeta levels. The plasma of 332 patients, who had undergone neuropsychological testing before and 3 and 12 months after coronary artery bypass graft surgery, was analyzed for Abeta(42) and Abeta(40). Patients were classified as having preexisting cognitive impairment if cognitive function was decreased in two or more tests compared with a healthy control group, and postoperative cognitive dysfunction was defined as a decline in two or more tests compared with the group mean baseline score. Preexisting cognitive impairment was present in 117 patients (35.2%), and postoperative cognitive dysfunction was present in 40 (12%) at 3 months and 41 (13%) at 12 months after surgery. Both plasma Abeta(42) and Abeta(40) levels assessed before the surgery were significantly lower in patients who later had postoperative cognitive dysfunction at 3 months. Decreased preoperative plasma levels of Abeta(42) and Abeta(40) in patients who exhibit postoperative cognitive dysfunction at 3 months suggest that postoperative cognitive dysfunction at this time may share a common mechanism with mild cognitive impairment and Alzheimer's disease. This process may be exacerbated by anesthesia.
Publisher: Wiley
Date: 05-1992
DOI: 10.1111/J.1440-1681.1992.TB00474.X
Abstract: 1. Eight male rabbits were implanted with Doppler flow probes around the lower abdominal aorta and left renal artery. A 2 week recovery period was allowed prior to the experiment. 2. Normal saline, gludopa at 25 micrograms/kg per min and at 100 micrograms/kg per min were each infused i.v. for 60 min. One week later the same protocol was administered to four of these animals in addition to DA-1 antagonist SCH 23390 (0.3 mg/kg i.v.) before gludopa infusion. 3. Gludopa elicited significant increases in urine flow, urinary sodium excretion and renal blood flow, and decreased renal vascular resistance. These changes were abolished by the DA-1 antagonist. Blood pressure, heart rate and hindlimb blood flow remained unchanged. 4. Urine dopamine excretion was increased 1200-fold and 7800-fold after gludopa administration at 25 micrograms/kg per min and 100 micrograms/kg per min, respectively, while plasma dopamine concentration and plasma renin activity (PRA) were not significantly altered. However, PRA was elevated by gludopa with DA-1 antagonism. 5. The renal vasodilation, natriuresis and diuresis produced by gludopa in conscious rabbits appears to be mediated by locally generated dopamine via DA-1 receptors.
Publisher: Elsevier BV
Date: 09-2011
DOI: 10.1016/J.BPA.2011.05.001
Abstract: Postoperative cognitive dysfunction (POCD) was originally thought to be associated with cardiac surgery, but has since been associated with non-cardiac surgery and even sedation for non-invasive procedures such as coronary angiography. The focus of POCD has thus shifted from the type of surgery or anaesthetic to patient susceptibility. The realisation that cognitive impairment, such as mild cognitive impairment (MCI - the prodrome for Alzheimer's disease (AD)), may already exist in many elderly patients who incidentally present for surgery beckons anaesthesia to align cognitive research with that of AD in order to draw valid parallels between the two disciplines. Long-term studies are required to understand if POCD is merely a transient phenomenon, or if it is the harbinger of long-term cognitive deterioration which may lead eventually to dementia. In this regard, the use of CSF analysis to diagnose AD many years before symptoms appear may identify susceptible in iduals. Furthermore, animal studies indicate that volatile anaesthestics may augment the pathological processes of AD by affecting amyloid-beta processing. Identification of a link between surgery/anaesthesia, POCD, MCI, and AD would create a unique opportunity to fast-track the development of clinical or pharmacological preventive strategies that would benefit a significant proportion of the population.
Publisher: Wiley
Date: 12-12-2005
DOI: 10.1111/J.1399-6576.2006.00893.X
Abstract: The application of statistical rules to determine post-operative cognitive dysfunction (POCD) has varied, and partially explains the wide range of reported incidences of POCD in the literature. The current study assessed the sensitivity and specificity of three commonly used statistical rules in a s le of coronary artery bypass graft (CABG) patients and healthy non-surgical controls. Two hundred and four CABG patients [mean age, 68.8 years standard deviation (SD), 7.0 years] completed neuropsychological assessment pre-operatively (baseline) and 1 week and 3 months post-operatively. Ninety age- and gender-matched non-surgical controls (mean age, 67.8 years SD, 7.9 years) completed the same tasks at the same time points. POCD was determined in each group using three rules: the 1SD decline on two or more tasks the 20% decline on 20% of tasks rule and a modified reliable change index. The modified reliable change index demonstrated the greatest combination of sensitivity and specificity. The 20% decline on 20% of tasks rule detected the largest incidence of impairment in the CABG group, but showed large incidences of false positive classifications in the control group. The 1SD rule detected the lowest incidence of POCD in the CABG group, but detected a larger incidence of impairment in the control group. The use of the modified reliable change index is recommended, given the sensitivity to change it displayed and the low rates of false positive classification in the control s le. The use of control groups in future research is also recommended.
Publisher: Wiley
Date: 07-1995
DOI: 10.1111/J.1440-1681.1995.TB02047.X
Abstract: 1. This study was designed to investigate the effects of isotonic saline loading on renal tubular and neurogenic dopamine (DA) in conscious rabbits. 2. Isotonic saline loading did not affect mean arterial pressure, heart rate or renal blood flow but markedly increased urine volume, sodium excretion and DA excretion. 3. Renal DA spillover was not affected by venous emptying, while renal noradrenaline (NA) spillover tended to decrease during saline loading. The ratio of % renal DA spillover to % renal NA spillover increased to 2.3 ± 0.6 ( P 0.05) 3h after saline loading. 4. Isotonic saline loading increased renal tubular DA production but had little effect on neurogenic DA release.
Publisher: Wiley
Date: 07-1995
DOI: 10.1111/J.1440-1681.1995.TB02048.X
Abstract: 1. Two groups of age‐ and sex‐matched subjects, eight healthy controls and 10 patients, suffering from recurrent vasodepressor syncope, participated in a study to examine autonomic function and sequential changes in power distribution of heart rate (HR) variability during graded head‐up tilt. 2. The following autonomic function tests were performed valsalva ratio, HR responses to deep breathing and posture, BP responses to sustained handgrip and postural change. Each subject was tilted at 15°, 30°, 45°, 60° and 80° head‐up, each for 15 min, or until symptoms occurred. The eight control subjects completed the tilt study without any symptoms, while all 10 patients developed presyncope and/or syncope at various tilt angles. 3. Resting blood pressure (BP) was lower in the patient group, while resting HR, autonomic function tests and resting HR variability components were similar in the two groups. 4. The control group showed a progressive increase in low frequency power component (LF) from supine to end tilt (ΔLF 20.06 ± 14.50%) and a progressive fall in high frequency (HF) component (ΔHF—24.62 ± 10.64%). In contrast, in the patient group, LF fell during tilt in the presyncope period (ΔLF ‐10.57 ± 12.93%, P 0.01 vs control group). HF and HF: LF ratio responses did not differ significantly in the two groups. 5. At end tilt, the increase in plasma noradrenaline was significantly greater in the control group than in the patient group (ΔNA 0.83 ± 0.27 vs 0.28 ± 0.14 pmol/mL, P 0.01). Plasma adrenaline: noradrenaline ratio at end tilt did not change in the control group, but increased significantly in the patient group (supine 0.07 ± 0.03, end tilt 0.16 ± 0.09, P 0.05). 6. It was concluded that sympathetic withdrawal plays a major role in the mechanism of vasodepressor syncope.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2015
DOI: 10.1097/ALN.0000000000000671
Abstract: This study investigated the prevalence of cognitive impairment in elderly noncardiac surgery patients and any association between preoperative cognitive impairment and postoperative cognitive dysfunction (POCD). Additionally, the incidence of cognitive decline at 12 months after surgery was identified. Three hundred patients for hip joint replacement and 51 nonsurgical controls aged 60 yr or older were studied in a prospective observational clinical trial. All study participants and controls completed a battery of eight neuropsychological tests before surgery and at 7 days, 3 months, and 12 months afterwards. Preoperative cognitive status was assessed using preexisting cognitive impairment (PreCI) defined as a decline of at least 2 SD on two or more of seven neuropsychological tests compared to population norms. POCD and cognitive decline were assessed using the reliable change index utilizing the results of the control group. PreCI was classified in 96 of 300 (32%) patients (95% CI, 23 to 43%). After surgery, 49 of 286 (17%) patients (95% CI, 13 to 22%) and 27 of 284 (10%) patients (95% CI, 6 to 13%) demonstrated POCD at 7 days and 3 months, respectively, while 7 of 271 (3%) patients (95% CI, 1 to 4%) demonstrated cognitive decline at 12 months. Patients with PreCI had a significantly increased incidence of POCD at 7 days and 3 months and cognitive decline at 12 months. Patients with PreCI have an increased incidence of POCD and cognitive decline. PreCI is a good predictor of subsequent POCD and cognitive decline. The incidence of cognitive decline after 12 months in this group of patients is low.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2011
Publisher: S. Karger AG
Date: 2008
DOI: 10.1159/000119105
Abstract: i Background: /i Raised concentrations of plasma homocysteine and C-reactive protein (CRP) are associated with vascular disease and have also been implicated as independent risk factors for cognitive impairment in population studies. i Objectives: /i To investigate the association of plasma homocysteine and CRP with cognition in patients scheduled for coronary artery bypass graft (CABG) surgery. Cognition was assessed in 264 patients using a standard battery of neuropsychological tests. Patients were classified as having preexisting cognitive impairment (PreCI) by reference to a healthy control group or postoperative cognitive dysfunction (POCD) by reference to baseline test scores. i Results: /i PreCI was present in 37.3% of patients, and POCD was present in 18.3, 12.1 and 13.6% of patients at 1 week, 3 months and 12 months postoperatively. On multivariate analysis neither homocysteine nor CRP were independently associated with cognition at any testing time but were strongly associated with age and left ventricular function. i Conclusion: /i PreCI and POCD are present in a substantial proportion of patients undergoing CABG surgery but there is no independent association with either baseline homocysteine or CRP levels. It is possible that cognitive impairment may result from the vascular disease rather than a direct association with either homocysteine or CRP.
Publisher: Elsevier BV
Date: 10-2001
Publisher: Wiley
Date: 2022
DOI: 10.1111/ANAE.15613
Abstract: Peri‐operative neurocognitive disorders are the most common complication experienced by older in iduals undergoing anaesthesia and surgery. Peri‐operative neurocognitive disorders, particularly postoperative delirium, result in long‐term poor outcomes including: death dementia loss of independence and poor cognitive and functional outcomes. Recent changes to the nomenclature of these disorders aims to align peri‐operative neurocognitive disorders with cognitive disorders in the community, with consistent definitions and clinical diagnosis. Possible mechanisms include: undiagnosed neurodegenerative disease inflammation and resulting neuroinflammation neuronal damage and comorbid systemic disease. Pre‐operative frailty represents a significant risk for poor postoperative outcomes it is associated with an increase in the incidence of cognitive decline at 3 and 12 months postoperatively. In addition to cognitive decline, frailty is associated with poor functional outcomes following elective non‐cardiac surgery. It was recently shown that 29% of frail patients died or experienced institutionalisation or new disability within 90 days of major elective surgery. Identification of vulnerable patients before undergoing surgery and anaesthesia is the key to preventing peri‐operative neurocognitive disorders. Current approaches include: pre‐operative delirium and cognitive screening blood biomarker analysis intra‐operative management that may reduce the incidence of postoperative delirium such as lighter anaesthesia using processed electroencephalography devices and introduction of guidelines which may reduce or prevent delirium and postoperative neurocognitive disorders. This review will address these issues and advocate for an approach to care for older peri‐operative patients which starts in the community and continues throughout the pre‐operative, intra‐operative, postoperative and post‐discharge phases of care management, involving multidisciplinary medical teams, as well as family and caregivers wherever possible.
Publisher: Elsevier BV
Date: 06-2006
DOI: 10.1016/J.ATHORACSUR.2006.01.044
Abstract: The assessment of postoperative cognitive dysfunction after coronary artery bypass graft surgery is made with the repeated administration of cognitive tests. This classification is vulnerable to error, and it has been suggested that increasing the number of tests in a battery while maintaining constant inclusion criteria for postoperative cognitive dysfunction increases the rate of false positive classification of deterioration. The current study tested this by applying a constant rule for cognitive dysfunction using combinations of two to seven cognitive tests. Two hundred and four coronary artery bypass graft patients (surgical) and 90 healthy nonsurgical controls aged 55 years or older completed a battery of cognitive tests at baseline (preoperative) and 1 week later (postoperative). In both groups, postoperative cognitive dysfunction was classified using all unique combinations of two to seven cognitive tests when performance deteriorated on two or more tests by at least the value of the baseline standard deviation. The average incidence of cognitive dysfunction progressively increased in both groups as the number of cognitive tests increased from two (surgical: 13.3% control: 3.1%) to seven tests (surgical: 49.4% control: 41.1%). Increasing the number of tests used to classify postoperative cognitive dysfunction appears to increase the sensitivity to change in the coronary artery bypass graft group. However, accompanying false positive classifications suggest that this improved sensitivity reflected increased error. Future rules for postoperative cognitive dysfunction need to account for this error and include a control group.
Publisher: Cambridge University Press (CUP)
Date: 19-10-2010
DOI: 10.1017/S1041610210002036
Abstract: The growing need for lumbar puncture in order to obtain cerebrospinal fluid (CSF) for the diagnosis Alzheimer's disease is becoming increasingly apparent (Herskovits and Growdon, 2010). The concept of a CSF s ling unit specializing in lumbar puncture would seem the most plausible solution. Physicians and interns are not necessarily skilled in the procedure and neurologists perform lumbar puncture rarely.
Publisher: American Society of Neuroradiology (ASNR)
Date: 22-08-2014
DOI: 10.3174/AJNR.A3688
Publisher: Oxford University Press (OUP)
Date: 02-2007
DOI: 10.1016/J.ACN.2007.01.019
Abstract: The reliable change index (RCI) expresses change relative to its associated error, and is useful in the identification of postoperative cognitive dysfunction (POCD). This paper examines four common RCIs that each account for error in different ways. Three rules incorporate a constant correction for practice effects and are contrasted with the standard RCI that had no correction for practice. These rules are applied to 160 patients undergoing coronary artery bypass graft (CABG) surgery who completed neuropsychological assessments preoperatively and 1 week postoperatively using error and reliability data from a comparable healthy nonsurgical control group. The rules all identify POCD in a similar proportion of patients, but the use of the within-subject standard deviation (WSD), expressing the effects of random error, as an error estimate is a theoretically appropriate denominator when a constant error correction, removing the effects of systematic error, is deducted from the numerator in a RCI.
Publisher: Elsevier BV
Date: 07-2014
No related grants have been discovered for Lisbeth Evered.