P A Kristensen

Bio: P A Kristensen is an academic researcher from Copenhagen University Hospital. The author has contributed to research in topics: Postoperative cognitive dysfunction & Abdominal surgery. The author has an hindex of 4, co-authored 4 publications receiving 2356 citations.

Cognitive dysfunction 1-2 years after non-cardiac surgery in the elderly. ISPOCD group. International Study of Post-Operative Cognitive Dysfunction.

Abstract: Background: Postoperative cognitive dysfunction (POCD) is a well-recognised complication of cardiac surgery, but evidence of POCD after general surgery has been lacking. We recently showed that POCD was present in 9.9% of elderly patients 3 months after major non-cardiac surgery. The aim of the present study was to investigate whether POCD persists for 1–2 years after operation. Methods: A total of 336 elderly patients (median age 69 years, range 60–86) was studied after major surgery under general anesthesia. Psychometric testing was performed before surgery and at a median of 7, 98 and 532 days postoperatively using a neuropsychological test battery with 7 subtests. A control group of 47 non-hospitalised volunteers of similar age were tested with the test battery at the same intervals. Results: 1–2 years after surgery, 35 out of 336 patients (10.4%, CI: 7.2–13.7%) had cognitive dysfunction. Three patients had POCD at all three postoperative test sessions (0.9%). From our definition of POCD, there is only a 1:64 000 likelihood that a single subject would have POCD at all three test points by chance. Logistic regression analysis identified age, early POCD, and infection within the first three postoperative months as significant risk factors for long-term cognitive dysfunction. Five of 47 normal controls fulfilled the criteria for cognitive dysfunction 1–2 years after initial testing (10.6%, CI: 1.8–19.4%), i.e. a similar incidence of age-related cognitive impairment as among patients. Conclusion: POCD is a reversible condition in the majority of cases but may persist in approximately 1% of patients.

Benzodiazepines and postoperative cognitive dysfunction in the elderly. ISPOCD Group. International Study of Postoperative Cognitive Dysfunction.

Abstract: Postoperative cognitive dysfunction (POCD) has been attributed to long-acting sedatives. We hypothesized that diazepam and its active metabolites could be detected in blood after surgery and correlated with POCD, 1 week after surgery in elderly patients. We studied 35 patients, 60 yr or older, undergoing abdominal surgery with general anaesthesia, including diazepam. Neuropsychological tests were performed before surgery and at discharge, where blood concentrations (free fraction) of benzodiazepines were also measured. POCD was found in 17 patients (48.6%). Diazepam or desmethyldiazepam was detected in 34 patients; median postoperative blood concentrations were 0.06 and 0.10 mumol kg-1, respectively. In a multiple regression analysis considering age, duration of anaesthesia and blood concentrations of diazepam and desmethyldiazepam, only age was found to correlate with the composite z-score (F test, P

Do blood concentrations of neurone specific enolase and S-100 beta protein reflect cognitive dysfunction after abdominal surgery?ISPOCD Group.

Abstract: Neurone specific enolase (NSE) and S-100 beta protein have been used as markers of brain damage. We hypothesized that blood concentrations of NSE and S-100 beta protein reflect cognitive dysfunction after abdominal surgery. We studied 65 elderly patients in whom neuropsychological testing was performed before abdominal surgery, at discharge from hospital and after 3 months. Serum concentrations of NSE and S-100 beta protein were measured before surgery and after 24, 48 and 72 h. Serum concentrations of S-100 beta protein increased significantly while NSE concentrations decreased significantly. The increase in S-100 beta protein concentration after 48 h was significantly greater in patients with delirium. No correlation was found between cognitive dysfunction and S-100 beta protein or NSE concentration. We conclude that blood concentrations of S-100 beta protein increase after abdominal surgery and may be related to postoperative delirium.

Delirium in mechanically ventilated patients: validity and reliability of the confusion assessment method for the intensive care unit (CAM-ICU).

Abstract: ContextDelirium is a common problem in the intensive care unit (ICU). Accurate diagnosis is limited by the difficulty of communicating with mechanically ventilated patients and by lack of a validated delirium instrument for use in the ICU.ObjectivesTo validate a delirium assessment instrument that uses standardized nonverbal assessments for mechanically ventilated patients and to determine the occurrence rate of delirium in such patients.Design and SettingProspective cohort study testing the Confusion Assessment Method for ICU Patients (CAM-ICU) in the adult medical and coronary ICUs of a US university-based medical center.ParticipantsA total of 111 consecutive patients who were mechanically ventilated were enrolled from February 1, 2000, to July 15, 2000, of whom 96 (86.5%) were evaluable for the development of delirium and 15 (13.5%) were excluded because they remained comatose throughout the investigation.Main Outcome MeasuresOccurrence rate of delirium and sensitivity, specificity, and interrater reliability of delirium assessments using the CAM-ICU, made daily by 2 critical care study nurses, compared with assessments by delirium experts using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria.ResultsA total of 471 daily paired evaluations were completed. Compared with the reference standard for diagnosing delirium, 2 study nurses using the CAM-ICU had sensitivities of 100% and 93%, specificities of 98% and 100%, and high interrater reliability (κ = 0.96; 95% confidence interval, 0.92-0.99). Interrater reliability measures across subgroup comparisons showed κ values of 0.92 for those aged 65 years or older, 0.99 for those with suspected dementia, or 0.94 for those with Acute Physiology and Chronic Health Evaluation II scores at or above the median value of 23 (all P<.001). Comparing sensitivity and specificity between patient subgroups according to age, suspected dementia, or severity of illness showed no significant differences. The mean (SD) CAM-ICU administration time was 2 (1) minutes. Reference standard diagnoses of delirium, stupor, and coma occurred in 25.2%, 21.3%, and 28.5% of all observations, respectively. Delirium occurred in 80 (83.3%) patients during their ICU stay for a mean (SD) of 2.4 (1.6) days. Delirium was even present in 39.5% of alert or easily aroused patient observations by the reference standard and persisted in 10.4% of patients at hospital discharge.ConclusionsDelirium, a complication not currently monitored in the ICU setting, is extremely common in mechanically ventilated patients. The CAM-ICU appears to be rapid, valid, and reliable for diagnosing delirium in the ICU setting and may be a useful instrument for both clinical and research purposes.

Guidelines for perioperative care in elective colonic surgery: Enhanced recovery after surgery (ERAS®) society recommendations

Abstract: This is the fourth updated Enhanced Recovery After Surgery (ERAS®) Society guideline presenting a consensus for optimal perioperative care in colorectal surgery and providing graded recommendations for each ERAS item within the ERAS® protocol. A wide database search on English literature publications was performed. Studies on each item within the protocol were selected with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohorts and examined, reviewed and graded according to Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. All recommendations on ERAS® protocol items are based on best available evidence; good-quality trials; meta-analyses of good-quality trials; or large cohort studies. The level of evidence for the use of each item is presented accordingly. The evidence base and recommendation for items within the multimodal perioperative care pathway are presented by the ERAS® Society in this comprehensive consensus review.

Delirium in Elderly Patients and the Risk of Postdischarge Mortality, Institutionalization, and Dementia: A Meta-analysis

Abstract: Context Delirium is a common and serious complication in elderly patients Evidence suggests that delirium is associated with long-term poor outcome but delirium often occurs in individuals with more severe underlying disease Objective To assess the association between delirium in elderly patients and long-term poor outcome, defined as mortality, institutionalization, or dementia, while controlling for important confounders Data Sources A systematic search of studies published between January 1981 and April 2010 was conducted using the databases of MEDLINE, EMBASE, PsycINFO, and CINAHL Study Selection Observational studies of elderly patients with delirium as a study variable and data on mortality, institutionalization, or dementia after a minimum follow-up of 3 months, and published in the English or Dutch language Titles, abstracts, and articles were reviewed independently by 2 of the authors Of 2939 references in the original search, 51 relevant articles were identified Data Extraction Information on study design, characteristics of the study population, and outcome were extracted Quality of studies was assessed based on elements of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist for cohort studies Data Synthesis The primary analyses included only high-quality studies with statistical control for age, sex, comorbid illness or illness severity, and baseline dementia Pooled-effect estimates were calculated with random-effects models The primary analysis with adjusted hazard ratios (HRs) showed that delirium is associated with an increased risk of death compared with controls after an average follow-up of 227 months (7 studies; 271/714 patients [380%] with delirium, 616/2243 controls [275%]; HR, 195 [95% confidence interval {CI}, 151-252]; I2, 440%) Moreover, patients who had experienced delirium were also at increased risk of institutionalization (7 studies; average follow-up, 146 months; 176/527 patients [334%] with delirium and 219/2052 controls [107%]; odds ratio [OR], 241 [95% CI, 177-329]; I2, 0%) and dementia (2 studies; average follow-up, 41 years; 35/56 patients [625%] with delirium and 15/185 controls [81%]; OR, 1252 [95% CI, 186-8421]; I2, 524%) The sensitivity, trim-and-fill, and secondary analyses with unadjusted high-quality risk estimates stratified according to the study characteristics confirmed the robustness of these results Conclusion This meta-analysis provides evidence that delirium in elderly patients is associated with poor outcome independent of important confounders, such as age, sex, comorbid illness or illness severity, and baseline dementia

Predictors of Cognitive Dysfunction after Major Noncardiac Surgery

Abstract: This article and its accompanying editorial have been selected for the ANESTHESIOLOGYCME Program. After reading both articles, go to http://www.asahq.org/journal-cme to take the test and apply for Category 1 credit. Complete instructions may be found in the CME section at the back of this issue. Background: The authors designed a prospective longitudinal study to investigate the hypothesis that advancing age is a risk factor for postoperative cognitive dysfunction (POCD) after major noncardiac surgery and the impact of POCD on mortality in the first year after surgery. Methods: One thousand sixty-four patients aged 18 yr or older completed neuropsychological tests before surgery, at hospital discharge, and 3 months after surgery. Patients were categorized as young (18‐39 yr), middle-aged (40‐59 yr), or elderly (60 yr or older). At 1 yr after surgery, patients were contacted to determine their survival status. Results: At hospital discharge, POCD was present in 117 (36.6%) young, 112 (30.4%) middle-aged, and 138 (41.4%) elderly patients. There was a significant difference between all age groups and the age-matched control subjects (P < 0.001). At 3 months after surgery, POCD was present in 16 (5.7%) young, 19 (5.6%) middle-aged, and 39 (12.7%) elderly patients. At this time point, the prevalence of cognitive dysfunction was similar between age-matched controls and young and middle-aged patients but significantly higher in elderly patients compared to elderly control subjects (P < 0.001). The independent risk factors for POCD at 3 months after surgery were increasing age, lower educational level, a history of previous cerebral vascular accident with no residual impairment, and POCD at hospital discharge. Patients with POCD at hospital discharge were more likely to die in the first 3 months after surgery (P 0.02). Likewise, patients who had POCD at both hospital discharge and 3 months after surgery were more likely to die in the first year after surgery (P 0.02). Conclusions: Cognitive dysfunction is common in adult patients of all ages at hospital discharge after major noncardiac surgery, but only the elderly (aged 60 yr or older) are at significant risk for long-term cognitive problems. Patients with POCD are at an increased risk of death in the first year after surgery. POSTOPERATIVE cognitive dysfunction (POCD) is often associated with cardiac surgery, but less is known about the prevalence of this problem after other types of surgery. 1,2 In 1998, the International Study of Postoperative Cognitive Dysfunction (ISPOCD1) evaluated cognitive decline in 1,218 elderly patients, aged 60 yr or older, who had undergone major noncardiac surgery, and found that cognitive dysfunction was present in 26% of older patients 1 week after surgery and in 10% 3 months after surgery. 3 However, this study had significant differences in the incidence of early POCD at the 13 participating hospitals, placing this finding in question. Research evaluating cognitive decline after cardiac and noncardiac surgery has primarily focused on older patients, who might have an increased vulnerability to neurologic deterioration. 1,3,4 However, the cognitive effects of surgery and anesthesia in younger adults are poorly understood, making it difficult to determine whether advancing age is the primary risk factor for this complication. Studies on normal aging have shown that abrupt declines in cognitive function in older adults are associated with early death. 5,6 The relation between POCD and mortality has not been reported. To investigate the hypothesis that advancing age is a risk factor for POCD, we designed a prospective cohort study evaluating the incidence of early (hospital discharge) and late (3 months after surgery) cognitive dysfunction in adults of all ages undergoing elective, major noncardiac surgery. This study used the same neuropsychological methodology as the ISPOCD1 study in an attempt to replicate its results at a single institution. 3 Patients were also followed to determine the impact of POCD on survival in the first year after major surgery. A companion article analyzes the type and severity of cognitive impairment in the elderly patients in this study. 7

Delirium in Elderly Patients and the Risk of Postdischarge Mortality, Institutionalization, and Dementia

Abstract: DELIRIUM IS A SYNDROME OF acutely altered mental status characterized by inattent ion and a f luctuat ing course. With occurrence rates of up to half of older patients postoperatively, and even higher in elderly patients admitted to intensive care units, delirium is the most common complication in hospitalized older people. Delirium causes distress to patients and caregivers, has been associated with increased morbidity and mortality, and is a major burden to health care services in terms of expenditures. Numerous studies have addressed the long-term prognosis of older individuals who experienced delirium during hospitalization. The evidence that these studies provide is not entirely consistent (eg, older patients with delirium experienced increased long-term mortality in one study, but not in another). Elements of study design, such as delirium and outcome ascertainment and time to follow-up, may affect conclusions. Whether delirium independently contributes to poor outcome or merely represents a marker of underlying disease is especially relevant. The long-term detrimental seAuthor Affiliations: Department of Geriatric Medicine, Medical Center Alkmaar, Alkmaar, the Netherlands (Mr Witlox and Dr de Jonghe); Department of Neurology, Academic Medical Center, Amsterdam, the Netherlands(MsEurelingsandDrsEikelenboomandvanGool); Department of Geriatric Medicine, Kennemer Gasthuis, Haarlem,theNetherlands(DrKalisvaart);andGGZinGeest, Amsterdam, the Netherlands (Dr Eikelenboom). Corresponding Author: Willem A. van Gool, MD, PhD, Department of Neurology, Academic Medical Center, PO Box 22700, 1100 DE Amsterdam, the Netherlands (w.a.vangool@amc.uva.nl). Context Delirium is a common and serious complication in elderly patients. Evidence suggests that delirium is associated with long-term poor outcome but delirium often occurs in individuals with more severe underlying disease.