Incidence and predictors of postoperative delirium in the older acute care surgery population: a prospective study

Background: Among older inpatients, the highest incidence of delirium is within the surgical population. Limited data are available regarding postoperative delirium risk in the acute care surgical population. The purpose of our study was to establish the incidence of and risk factors for delirium in an older acute care surgery population. Methods: Patients aged 65 years or more who had undergone acute care surgery between April 2014 and September 2015 at 2 university-affiliated hospitals in Alberta were followed prospectively and screened for delirium by means of a validated chart review method. Delirium duration was recorded. We used separate multivariable logistic regression models to identify independent predictors for overall delirium and longer episodes of delirium (duration ≥ 48 h). Results: Of the 322 patients included, 73 (22.7%) were identified as having experienced delirium, with 49 (15.2%) experiencing longer episodes of delirium. Postoperative delirium risk factors included Foley catheter use, intestinal surgery, gallbladder surgery, appendix surgery, intensive care unit (ICU) admission and mild to moderate frailty. Risk factors for prolonged postoperative delirium included Foley catheter use and mild to moderate frailty. Surgical approach (open v. laparoscopic) and overall operative time were not found to be significant. Conclusion: In keeping with the literature, our study identified Foley catheter use, frailty and ICU admission as risk factors for delirium in older acute care surgical patients. We also identified an association between delirium risk and the specific surgical procedure performed. Understanding these risk factors can assist in prevention and directed interventions for this high-risk population.

Contexte: Parmi les patients âgés, l'incidence la plus élevée d'épisodes de délire s'observe chez les patients opérés. On dispose de données limitées au sujet du risque de délire postopératoire chez les patients soumis à une chirurgie d'urgence. Le but de notre étude était de connaître l'incidence des épisodes de délire et les facteurs de risque chez la population âgée soumise à une chirurgie d'urgence. Méthodes: Nous avons suivi de façon prospective les patients de 65 ans ou plus soumis à une chirurgie d'urgence entre avril 2014 et septembre 2015 dans 2 centres hospitaliers universitaires de l'Alberta et nous avons recensé les épisodes de délire au moyen d'une méthode validée d'analyse des dossiers. La durée des épisodes de délire a été notée. Nous avons utilisé des modèles séparés d'analyse de régression logistique multivariée pour dégager les prédicteurs indépendants des épisodes globaux de délire et des épisodes plus longs (durée ≥ 48 h). Résultats: Parmi les 322 patients inclus, 73 (22,7 %) ont manifesté un épisode de délire, dont 49 (15,2 %) un épisode plus long. Les facteurs de risque à l'égard des épisodes de délire postopératoire ont inclus : l'emploi d'une sonde Foley, la chirurgie intestinale, la chirurgie de la vésicule biliaire, l'appendicectomie, un séjour à l'unité de soins intensifs (USI) et un état de fragilité léger ou modéré. Les facteurs de risque à l'égard d'un épisode de délire postopératoire prolongé ont inclus : l'emploi d'une sonde Foley et un état de fragilité léger ou modéré. L'approche chirurgicale (ouverte c. laparoscopique) et la durée globale de l'intervention n'ont pas joué un rôle significatif. Conclusion: Faisant écho à la littérature publiée, notre étude a identifié l'emploi de la sonde Foley, l'état de fragilité et le séjour à l'USI comme des facteurs de risque de délire chez les patients âgés soumis à une chirurgie d'urgence. Nous avons aussi observé un lien entre le risque de délire et certains types d'interventions chirurgicales. En comprenant mieux ces facteurs, il sera possible de prévenir ces épisodes et d'orienter les interventions chez cette population à risque élevé.

Quality of care and mortality are worse in chronic kidney disease patients living in remote areas.

Many patients with non-dialysis dependent chronic kidney disease (CKD) live far from the closest nephrologist; although reversible, this might constitute a barrier to optimal care. In order to evaluate outcomes, we selected 31,452 outpatients older than 18 years with an estimated glomerular filtration rate (eGFR) less than 45 ml/min per 1.73 m² who had serum creatinine measured at least once during 2005 in Alberta, Canada. We then used logistic regression to examine the association between outcomes of 6545 patients who lived more than 50 km from the nearest nephrologist. Over a median follow-up of 27 months, 7684 participants died and 15,075 were hospitalized at least once. Compared with those living within 50 km, those further away were significantly less likely to visit a nephrologist or a multidisciplinary CKD clinic within 18 months of the index measurement of the eGFR. Similarly, remote dwellers with diabetes were significantly less likely to have hemoglobin A1c evaluated within 1 year of the index eGFR measurement, to have urinary albumin assessed biannually, or to receive an angiotensin converting enzyme inhibitor or receptor blocker in the setting of diabetes or proteinuria. Remote-dwelling participants were also significantly more likely to die or be hospitalized during follow-up than those living closer. Thus, among people with CKD, remote dwellers were less likely to receive specialist care, recommended laboratory testing, and appropriate medications, and were more likely to die or be hospitalized compared with those living closer to a nephrologist.

Trace element status in hemodialysis patients.

Patients with chronic kidney disease undergoing hemodialysis (HD) are potentially at risk of deficiency and excess of trace elements. HD exposes patients to large volumes of water (>120 l/week) in the form of dialysate. Although levels of certain ions (such as potassium and calcium) are carefully regulated in dialysate, many others are measured infrequently, if ever. As a result, substances in lower concentrations in the dialysis may be leached from the body. Conversely, toxic trace elements present in water but not in blood may accumulate and cause toxicity. Given that essential trace elements play key roles in multiple biological systems including immunological defense against oxidation and infection, it has been hypothesized that the increased morbidity and mortality seen in HD patients may in part be due to the imbalance of trace elements that has not been recognized. A recent systematic review has shown that compared with healthy controls, HD patients have significantly lower blood levels of zinc, manganese, and selenium, while blood levels of lead are likely to accumulate. Other trace elements, such as mercury and arsenic, are biologically plausible causes of excess mortality in dialysis patients, but available evidence is inconclusive as to whether they consistently accumulate in this population. Whether altered trace element levels are potentially reversible causes of adverse clinical outcomes in dialysis patients remains to be determined. This review highlights key issues related to this hypothesis, with special emphasis on zinc, manganese, selenium, lead, mercury, and arsenic.

Vitamin D insufficiency and treatment with oral vitamin D3 in northern-dwelling patients with chronic kidney disease.

BACKGROUND: Vitamin D insufficiency is common in people living at northern latitudes and those with chronic kidney disease (CKD). We studied persons with both of these risk factors to determine the prevalence of vitamin D insufficiency and whether serum 25-hydroxyvitamin D (25(OH)D) levels were affected by oral vitamin D3 supplementation. METHODS: This was a prospective controlled trial of 128 patients with stage 3-5 non-dialysis dependent CKD. Patients were assigned to the intervention (oral vitamin D3 1,000 IU/day) in a 1:1 ratio at the discretion of the attending dietitian. Serum biochemical markers were measured at baseline (May-July) and after 3 months of follow-up. There were 63 control and 65 intervention subjects. RESULTS: Mean 25(OH)D levels increased significantly higher in the treatment group (mean increase from baseline: 10.3+/-10.4 ng/mL vs. 0.8+/-6.8 ng/mL, p<0.0001). This difference remained significant after adjustment for differing baseline characteristics between groups (p<0.0001). Treatment with oral vitamin D3 reduced vitamin D insufficiency by 37%, as compared with a 2% increase in prevalence among the control group (p<0.0001). Considering the entire study population, 93% of patients had levels less than <30 ng/mL at least once during the study. CONCLUSION: Vitamin D insufficiency is highly prevalent in northern-dwelling patients with stage 3-5 CKD, and is moderated by oral supplementation with 1,000 IU of vitamin D3 daily.

Sex differences in the treatment and outcome of emergency general surgery.

BACKGROUND: Sociodemographic characteristics, such as sex, have been shown to influence health care delivery. Acute care surgery models are effective in decreasing mortality and morbidity after emergency surgeries, but sex-based differences in delivery and outcomes have not been explored. Our objective was to explore sex associated differences in the patient characteristics and clinical outcomes of those admitted to emergency general surgery. METHODS: A post-hoc analysis of 512 emergency general surgical patients admitted consecutively to two tertiary care hospitals in Alberta Canada, between April 1, 2014 and July 31, 2015. We measured associations between sex and patient demographics, pre-, intra- and post-operative delivery of care, as well as post-operative outcomes. FINDINGS: Of those excluded from the analysis, older females were more likely to undergo conservative management compared to older men (41% vs 34%, p = 0.03). Overall, there were no differences between sexes for time from admission to surgery, time spent in surgery, overall complication rate, mortality, hospital length of stay, or discharge disposition. Women were more likely to have a cancer diagnosis [OR 4.12 (95% CI: 1.61-10.5), p = 0.003, adjusted for age], while men were more likely to receive hernia surgery [OR 2.33 (95% CI 1.35-4.02), p = 0.002, adjusted for age and Charlson Comorbidity Index]. Finally, men were more likely to have a major respiratory complication [OR 2.73 (95% CI: 1.19-6.24), p = 0.02, adjusted for age]. CONCLUSIONS: Only two differences in peri and post-operative complications between sexes were noted, which suggests sex-based disparity in quality of care is limited once a decision has been made to operate. Future studies with larger databases are needed to corroborate our findings and investigate potential sex biases in surgical versus conservative management.

Selective joint denervation promotes knee osteoarthritis in the aging rat.

Osteoarthritis is the most common joint disorder with aging, but its cause is unknown. Mice lose joint afferents with aging, and this loss precedes development of osteoarthritis. We hypothesized a loss of joint afferents is involved in the pathogenesis of osteoarthritis. To test this hypothesis, we denervated knee joints of 16 rats at age 2 months, by intra-articular injection of an immunotoxin. The immunotoxin killed neurons after retrograde axonal transport to the cell body. At 16 or 24 months follow-up, each joint was histologically assessed and assigned an osteoarthritis score. At follow-up, the number of joint afferents had spontaneously decreased by 42% in control knees and 69% in denervated knees. We found that control knees developed osteoarthritic changes with aging. However, denervated knees had far more severe changes, as evidenced by a 54% higher average osteoarthritis score than control knees (P = 0.0016, both groups 16 knees). These results suggest a loss of afferents predisposes a joint to osteoarthritis. We propose the spontaneous loss of neurons with aging may be a normal developmental process. To explain the mechanism causing osteoarthritis, we suggest denervation permits aberrant joint loading, either by disturbing neuromuscular joint control, or by inducing joint laxity after neurogenic loss of tissue homeostasis.

Changes in bone scans after anterior cruciate ligament reconstruction: a prospective study.

BACKGROUND: Whether anterior cruciate ligament reconstruction retards the progression of osteoarthrosis is not established. Bone scintigraphy can be useful for monitoring the course of osteoarthrosis. Bone scan findings are abnormal in the majority of patients with anterior cruciate ligament deficiency. Three uptake patterns can be distinguished. HYPOTHESIS: Reconstruction corrects the three abnormal bone scan patterns seen in patients with anterior cruciate ligament deficiency. STUDY DESIGN: Prospective cohort study. METHODS: We performed bone scintigraphy in 80 patients, before and 2 years after anterior cruciate ligament reconstruction. RESULTS: Reconstruction consistently corrected type 2 bone scan pattern (meniscus scan) but not type 1 and 3 patterns (osteoarthrosis and cartilage ulcer scan). Correction of all three patterns decreased among patients who had longer duration of anterior cruciate ligament deficiency and was more reliable for the combined uptake of all three patterns among patients who had less than 6 months of deficiency. CONCLUSION: These findings indicate anterior cruciate ligament reconstruction protects the menisci. Reconstruction may be best performed within 6 months after injury.

Incidence and significance of inconclusive results in ultrasound for appendicitis in children and teenagers.

PURPOSE: Frustratingly, sonography to assess for appendicitis in children often leads to an inconclusive report (eg, "suspicious for appendicitis") or nonvisualization of the appendix. To aid in planning who to image and how to interpret the results, we investigated whether these 2 results were more frequent in teenagers than preteens and the prevalence of appendicitis associated with each result. METHODS: We retrospectively reviewed sonographic and surgical findings in patients <18 years (n = 189) referred with clinical suspicion of appendicitis over a 12-month period. Children (≤12.0 years old; n = 86) and teens (>12.0 years old; n = 103) were compared. RESULTS: Prevalence of appendicitis was 34% in each group, similar to other centres; 0% for those with negative ultrasound reports (0/35), 10% for nonvisualized appendix (8/84), 68% for inconclusive report (15/22), and 85% for positive ultrasound (41/48). Teens were significantly more likely to have an inconclusive ultrasound. Inconclusive reports were because of borderline findings (eg, appendix size near 6 mm; 9/22), body habitus, bowel gas, or unusual findings due in retrospect to perforation. The rate of nonvisualization of the appendix did not vary significantly with age (42% vs 47%). CONCLUSION: An inconclusive result of ultrasound for appendicitis was significantly more frequent in teens than in preteens and carried a high (68%) likelihood of appendicitis. Conversely, a nonvisualized appendix was equally frequent in teens and preteens, and had a low likelihood of appendicitis (only 10% positive). These findings encourage the use of ultrasound in preteens in particular and can assist interpretation of these common results.

Cardiovascular risk and management in chronic kidney disease.

Chronic kidney disease (CKD) is associated with accelerated progression of cardiovascular disease, perhaps because patients with CKD have a high burden of traditional cardiovascular risk factors in addition to a range of nontraditional risk factors such as inflammation and abnormal metabolism of calcium and phosphate. Although the cardiovascular burden of CKD is well documented, potentially beneficial therapies are sometimes underused in patients with stage 3-4 CKD and are rarely studied in patients on dialysis. In this Review, we describe the epidemiology of cardiovascular disease in patients with stage 3-5 CKD (excluding kidney transplant recipients) and outline cardiovascular risk factors that are relevant in this population; we then discuss the implications of this knowledge for the optimal management of cardiovascular risk in this setting. Finally, we highlight opportunities for further research.

Long term pharmacotherapy for obesity and overweight: updated meta-analysis.

OBJECTIVE: To summarise the long term efficacy of anti-obesity drugs in reducing weight and improving health status. DESIGN: Updated meta-analysis of randomised trials. DATA SOURCES: Medline, Embase, the Cochrane controlled trials register, the Current Science meta-register of controlled trials, and reference lists of identified articles. All data sources were searched from December 2002 (end date of last search) to December 2006. STUDIES REVIEWED: Double blind randomised placebo controlled trials of approved anti-obesity drugs used in adults (age over 18) for one year or longer. RESULTS: 30 trials of one to four years' duration met the inclusion criteria: 16 orlistat (n=10 631 participants), 10 sibutramine (n=2623), and four rimonabant (n=6365). Of these, 14 trials were new and 16 had previously been identified. Attrition rates averaged 30-40%. Compared with placebo, orlistat reduced weight by 2.9 kg (95% confidence interval 2.5 kg to 3.2 kg), sibutramine by 4.2 kg (3.6 kg to 4.7 kg), and rimonabant by 4.7 kg (4.1 kg to 5.3 kg). Patients receiving active drug treatment were significantly more likely to achieve 5% and 10% weight loss thresholds. Orlistat reduced the incidence of diabetes and improved concentrations of total cholesterol and low density lipoprotein cholesterol, blood pressure, and glycaemic control in patients with diabetes but increased rates of gastrointestinal side effects and slightly lowered concentrations of high density lipoprotein. Sibutramine improved [corrected] concentrations of high density lipoprotein cholesterol and triglycerides [corrected] Rimonabant improved concentrations of high density lipoprotein cholesterol and triglycerides, blood pressure, and glycaemic control in patients with diabetes but increased the risk of mood disorders. CONCLUSIONS: Orlistat, sibutramine, and rimonabant modestly reduce weight, have differing effects on cardiovascular risk profiles, and have specific adverse effects.

Educational intervention to reduce falls and fear of falling in patients after fragility fracture: results of a controlled pilot study.

OBJECTIVES: Falls and fear of falling are a major health problem. We sought to determine the effectiveness of an educational intervention in reducing fear of falling and preventing recurrent falls in community-dwelling patients after a fragility fracture. METHODS: One hundred two community-dwelling patients aged 50 years or older who fell and sustained a wrist fracture and were treated at Emergency Departments in Edmonton, Alberta, Canada (2001-2002) were allocated to either standardized educational leaflets and post-discharge telephone counseling regarding fall prevention strategies ("intervention") or attention-controls ("controls"). Main outcomes were fear of falling and recurrent falls 3 months after fracture. RESULTS: Mean age was 67 years and most patients were female (80%). The majority of falls (76%) leading to fracture occurred outdoors. Three months post-fracture, almost half of patients (48%) reported increased fear of falling and 11 of 102 (11%) reported falling again. The intervention did not reduce the fear of falling (43% had increased fear vs. 53% of controls, adjusted P value=0.55) or decrease recurrent falls (17% fell vs. 5% of controls, adjusted P value=0.059) within 3 months of fracture. CONCLUSIONS: An educational intervention undertaken in the Emergency Department was no more effective than usual care in reducing fear of falling or recurrent falls in community-dwelling patients. Future strategies must address a number of dimensions beyond simple education.

IGF-I and testosterone levels as predictors of bone mineral density in healthy, community-dwelling men.

OBJECTIVE: Age-related decline in IGF-I and gonadal hormones have been postulated to play an important role in the pathogenesis of age-related bone loss in men. In this cross-sectional study, the relation between serum IGF-I and gonadal hormones with bone mineral density (BMD) was examined in community-dwelling men. DESIGN AND SUBJECTS: Serum IGF-I, testosterone and BMD were examined in 61 community-dwelling men over the age of 27, who were randomly selected from the Calgary cohort of 1000 subjects in the Canadian Multicentre Osteoporosis Study. In the present study, IGF-I, serum testosterone, SHBG, free androgen index (FAI), parathyroid hormone (PTH), 25-hydroxy-vitamin D [25(OH)D] and other markers of bone turnover were measured. BMD was measured at the spine and hip (HOLOGIC 4500). Simple linear regression was used to assess the linear relation between IGF-I, testosterone, BMD and other biochemical markers of bone metabolism and potential confounding variables and subsequent multivariate regression models were constructed separately for each BMD measurement to assess the importance of IGF-I and testosterone in the presence of potential confounding variables. RESULTS: Serum IGF-I, FAI and SHBG significantly decreased as a function of age, whereas serum levels of PTH increased. Only 25(OH)D, total testosterone and FAI were positively associated with serum IGF-I after adjusting for age and BMI. Multiple linear regression models revealed that IGF-I was a significant predictor of BMD at the total hip, femoral neck and femoral trochanter neck (P < or = 0.001). In contrast, the FAI was a significant predictor of BMD at the lumbar spine and wards area (P < or = 0.011), and SHBG was a significant predictor at the total hip and femoral trochanter (P < or = 0.045). CONCLUSION: These data support the hypothesis that the age-related decline in bone mass in men is associated with declining levels of IGF-I and testosterone.

Vitamin D insufficiency in a population of healthy western Canadians.

BACKGROUND: People with low levels of vitamin D and its metabolites are at increased risk for osteoporotic fractures. We wished to ascertain levels of vitamin D in a representative sample of adult western Canadians, to help assess the level of risk. We evaluated the prevalence of vitamin D insufficiency, defined as 25-hydroxyvitamin D [25(OH)D] less than 40 nmol/L, and seasonal variations in 25(OH)D, parathyroid hormone and related biochemical indices in a community-dwelling population of healthy Canadians living in Calgary (latitude 51 degrees 07'N). METHODS: During calendar year 1999, we collected fasting overnight blood samples every 3 months from 60 men and 128 women (age range 27 to 89 years) who had volunteered to participate in another study. We used commercial radioimmunoassay kits to measure calciotrophic hormones and other biochemical indices. Regression models for longitudinal data were used to assess the effect of season and other potential predictors on individual parameters. RESULTS: For a total of 64 participants (34%), vitamin D insufficiency, defined as 25(OH)D less than 40 nmol/L, was recorded at least once out of the 4 sampling times. After adjustment for age, body mass index and holiday travel, we observed the anticipated rise in serum 25(OH)D from a mean of 57.3 (standard deviation [SD] 21.3) nmol/L in the winter to 62.9 (SD 28.8) nmol/L in spring (p = 0.001) and 71.6 (SD 23.6) nmol/L in summer (p < 0.001), with a subsequent decline to 52.9 (SD 17.2) nmol/L in the fall (p = 0.008). The anticipated inverse relation between 25(OH)D and parathyroid hormone was not consistently observed: after adjustment for age, sex, body mass index and serum calcium, serum levels of parathyroid hormone did decrease significantly, from 39.5 (SD 18.8) ng/L in winter to 36.3 (SD 17.8) ng/L in summer (p = 0.001), but they continued to decline to 34.5 (SD 17.3) ng/L in the fall (p < 0.001). There was no association between 25(OH)D and parathyroid hormone (p = 0.21). INTERPRETATION: We documented a high prevalence of vitamin D insufficiency, which warrants consideration of dietary vitamin D supplementation.