Multivariable model of postoperative delirium in cardiac surgery patients: proteomic and demographic contributions.

Background: Delirium following cardiac surgery is common, morbid, and costly, but may be prevented with risk stratification and targeted intervention. Preoperative protein signatures may identify patients at increased risk for worse postoperative outcomes, including delirium. In this study, we aimed to identify plasma protein biomarkers and develop a predictive model for postoperative delirium in older patients undergoing cardiac surgery, while also uncovering possible pathophysiological mechanisms. Methods: SOMAscan analysis of 1,305 proteins in the plasma from 57 older adults undergoing cardiac surgery requiring cardiopulmonary bypass was conducted to define delirium-specific protein signatures at baseline (PREOP) and postoperative day 2 (POD2). Selected proteins were validated in 115 patients using the ELLA multiplex immunoassay platform. Proteins were combined with clinical and demographic variables to build multivariable models that estimate the risk of postoperative delirium and bring light to the underlying pathophysiology. Results: A total of 115 and 85 proteins from SOMAscan analyses were found altered in delirious patients at PREOP and POD2, respectively (p<0.05). Using four criteria including associations with surgery, delirium, and biological plausibility, 12 biomarker candidates (Tukey's fold change (|tFC|)>1.4, Benjamini-Hochberg (BH)-p<0.01) were selected for ELLA multiplex validation. Eight proteins were significantly altered at PREOP, and seven proteins at POD2 (p<0.05), in patients who developed postoperative delirium compared to non-delirious patients. Statistical analyses of model fit resulted in the selection of a combination of age, sex, and three proteins (angiopoietin-2 (ANGPT2); C-C motif chemokine 5 (CCL5); and metalloproteinase inhibitor 1 (TIMP1); AUC=0.829) as the best performing predictive model for delirium at PREOP. The delirium-associated proteins identified as biomarker candidates are involved with inflammation, glial dysfunction, vascularization, and hemostasis, highlighting the multifactorial pathophysiology of delirium. Conclusion: Our study proposes a model of postoperative delirium that includes a combination of older age, female sex, and altered levels of three proteins. Our results support the identification of patients at higher risk of developing postoperative delirium after cardiac surgery and provide insights on the underlying pathophysiology. ClinicalTrials.gov ( NCT02546765 ).

Mistrust, misperceptions, and miscommunication: a qualitative study of preferences about kidney transplantation among African Americans.

BACKGROUND: Kidney transplantation rates in the United States are lower among African Americans than among whites. Well-documented racial disparities in access to transplantation explain some, but not all, of these differences. Prior survey-based research suggests that African American dialysis patients are less likely than whites to desire transplantation, but little research has focused on an in-depth exploration of preferences about kidney transplantation among African Americans. Thus, the purposes of this study were to explore preferences and to compare patients' expectations about transplantation with actual status on the transplant list. METHODS: We conducted semistructured interviews with 16 African Americans receiving chronic hemodialysis. We analyzed the interviews using the constant comparative method of qualitative analysis. We also reviewed the dialysis center's transplant list. RESULTS: Four dominant themes emerged: (1) varied desire for transplant; (2) concerns about donor source; (3) barriers to transplantation; and (4) lack of communication with nephrologists and the transplantation team. A thread of mistrust about equity in the transplantation process flowed through themes 2-4. In 7/16 cases, patients' understanding of their transplant listing status was discordant with their actual status. CONCLUSIONS: Our study suggests that many African Americans on hemodialysis are interested in kidney transplantation, but that interest is often tempered by concerns about transplantation, including misconceptions about the risks to recipients and donors. Mistrust about equity in the organ allocation process also contributed to ambivalence. The discordance between patients' perceptions of listing status and actual status suggests communication gaps between African American hemodialysis patients and physicians. Clinicians should avoid interpreting ambivalence about transplantation as lack of interest.

Measurement of post-operative cognitive dysfunction after cardiac surgery: a systematic review.

Post-operative cognitive dysfunction (POCD) is a decline in cognitive function from pre-operative levels, which has been frequently described after cardiac surgery. The purpose of this study was to examine the variability in the measurement and definitions for POCD using the framework of a 1995 Consensus Statement on measurement of POCD. Electronic medical literature databases were searched for the intersection of the search terms 'thoracic surgery' and 'cognition, dementia, and neuropsychological test.' Abstracts were reviewed independently by two reviewers. English articles with >50 participants published since 1995 that performed pre-operative and post-operative psychometric testing in patients undergoing cardiac surgery were reviewed. Data relevant to the measurement and definition of POCD were abstracted and compared with the recommendations of the Consensus Statement. Sixty-two studies of POCD in patients undergoing cardiac surgery were identified. Of these studies, the recommended neuropsychological tests were carried out in less than half of the studies. The cognitive domains measured most frequently were attention (n=56; 93%) and memory (n=57; 95%); motor skills were measured less frequently (n=36; 60%). Additionally, less than half of the studies examined anxiety and depression, performed neurological exam, or accounted for learning. Four definitions of POCD emerged: per cent decline (n=15), standard deviation decline (n=14), factor analysis (n=13), and analysis of performance on individual tests (n=12). There is marked variability in the measurement and definition of POCD. This heterogeneity may impede progress by reducing the ability to compare studies on the causes and treatment of POCD.

Delirium accelerates cognitive decline in Alzheimer disease.

OBJECTIVE: To examine the impact of delirium on the trajectory of cognitive function in a cohort of patients with Alzheimer disease (AD). METHODS: A secondary analysis of data collected from a large prospective cohort, the Massachusetts Alzheimer's Disease Research Center's patient registry, examined cognitive performance over time in patients who developed (n = 72) or did not develop (n = 336) delirium during the course of their illnesses. Cognitive performance was measured by change in score on the Information-Memory-Concentration (IMC) subtest of the Blessed Dementia Rating Scale. Delirium was identified using a previously validated chart review method. Using linear mixed regression models, rates of cognitive change were calculated, controlling for age, sex, education, comorbid medical diagnoses, family history of dementia, dementia severity score, and duration of symptoms before diagnosis. RESULTS: A significant acceleration in the slope of cognitive decline occurs following an episode of delirium. Among patients who developed delirium, the average decline at baseline for performance on the IMC was 2.5 points per year, but after an episode of delirium there was further decline to an average of 4.9 points per year (p = 0.001). Across groups, the rate of change in IMC score occurred about three times faster in those who had delirium compared to those who did not. CONCLUSIONS: Delirium can accelerate the trajectory of cognitive decline in patients with Alzheimer disease (AD). The information from this study provides the foundation for future randomized intervention studies to determine whether prevention of delirium might ameliorate or delay cognitive decline in patients with AD.

Delirium is associated with early postoperative cognitive dysfunction.

The purpose of this analysis was to determine if postoperative delirium was associated with early postoperative cognitive dysfunction (at 7 days) and long-term postoperative cognitive dysfunction (at 3 months). The International Study of Postoperative Cognitive Dysfunction recruited 1218 subjects >or= 60 years old undergoing elective, non-cardiac surgery. Postoperatively, subjects were evaluated for delirium using the criteria of the Diagnostic and Statistical Manual. Subjects underwent neuropsychological testing pre-operatively and postoperatively at 7 days (n = 1018) and 3 months (n = 946). Postoperative cognitive dysfunction was defined as a composite Z-score > 2 across tests or at least two individual test Z-scores > 2. Subjects with delirium were significantly less likely to participate in postoperative testing. Delirium was associated with an increased incidence of early postoperative cognitive dysfunction (adjusted risk ratio 1.6, 95% CI 1.1-2.1), but not long-term postoperative cognitive dysfunction (adjusted risk ratio 1.3, 95% CI 0.6-2.4). Delirium was associated with early postoperative cognitive dysfunction, but the relationship of delirium to long-term postoperative cognitive dysfunction remains unclear.

Right heart catheterization and cardiac complications in patients undergoing noncardiac surgery: an observational study.

CONTEXT: Right heart catheterization (RHC) is commonly performed before high-risk noncardiac surgery, but the benefit of this strategy remains unproven. OBJECTIVE: To evaluate the relationship between use of perioperative RHC and postoperative cardiac complication rates in patients undergoing major noncardiac surgery. DESIGN: Prospective, observational cohort study. SETTING: Tertiary care teaching hospital in the United States. PATIENTS: Patients (n = 4059 aged >/=50 years) who underwent major elective noncardiac procedures with an expected length of stay of 2 or more days between July 18, 1989, and February 28, 1994. Two hundred twenty one patients had RHC and 3838 did not. MAIN OUTCOME MEASURE: Combined end point of major postoperative cardiac events, including myocardial infarction, unstable angina, cardiogenic pulmonary edema, ventricular fibrillation, documented ventricular tachycardia or primary cardiac arrest, and sustained complete heart block, classified by a reviewer blinded to preoperative data. RESULTS: Major cardiac events occurred in 171 patients (4.2%). Patients who underwent perioperative RHC had a 3-fold increase in incidence of major postoperative cardiac events (34 [15.4%] vs 137 [3.6%]; P<.001). In multivariate analyses, the adjusted odds ratios (ORs) for postoperative major cardiac and noncardiac events in patients undergoing RHC were 2.0 (95% confidence interval [CI], 1.3-3.2) and 2.1 (95% CI, 1.2-3.5), respectively. In a case-control analysis of a subset of 215 matched pairs of patients who did and did not undergo RHC, adjusted for propensity of RHC and type of procedure, patients who underwent perioperative RHC also had increased risk of postoperative congestive heart failure (OR, 2.9; 95% CI, 1.4-6.2) and major noncardiac events (OR, 2.2; 95% CI, 1.4-4.9). CONCLUSIONS: No evidence was found of reduction in complication rates associated with use of perioperative RHC in this population. Because of the morbidity and the high costs associated with RHC, the impact of this intervention in perioperative care should be evaluated in randomized trials.

Reducing delirium after hip fracture: a randomized trial.

OBJECTIVES: Delirium (or acute confusional state) affects 35% to 65% of patients after hip-fracture repair, and has been independently associated with poor functional recovery. We performed a randomized trial in an orthopedic surgery service at an academic hospital to determine whether proactive geriatrics consultation can reduce delirium after hip fracture. DESIGN: Prospective, randomized, blinded. SETTING: Inpatient academic tertiary medical center. PARTICIPANTS: 126 consenting patients 65 and older (mean age 79 +/- 8 years, 79% women) admitted emergently for surgical repair of hip fracture. MEASUREMENTS: Detailed assessment through interviews with patients and designated proxies and review of medical records was performed at enrollment to ascertain prefracture status. Subjects were then randomized to proactive geriatrics consultation, which began preoperatively or within 24 hours of surgery, or "usual care." A geriatrician made daily visits for the duration of the hospitalization and made targeted recommendations based on a structured protocol. To ascertain study outcomes, all subjects underwent daily, blinded interviews for the duration of their hospitalization, including the Mini-Mental State Examination (MMSE), the Delirium Symptom Interview (DSI), and the Memorial Delirium Assessment Scale (MDAS). Delirium was diagnosed using the Confusion Assessment Method (CAM) algorithm. RESULTS: The 62 patients randomized to geriatrics consultation were not significantly different (P>.1) from the 64 usual-care patients in terms of age, gender, prefracture dementia, comorbidity, type of hip fracture, or type of surgical repair. Sixty-one percent of geriatrics consultation patients were seen preoperatively and all were seen within 24 hours postoperatively. A mean of 10 recommendations were made throughout the duration of the hospitalization, with 77% adherence by the orthopedics team. Delirium occurred in 20 /62 (32%) intervention patients, versus 32 / 64 (50%) usual-care patients (P =.04), representing a relative risk of 0.64 (95% confidence interval (CI) = 0.37-0.98) for the consultation group. One case of delirium was prevented for every 5.6 patients in the geriatrics consultation group. There was an even greater reduction in cases of severe delirium, occurring in 7/ 60 (12%) of intervention patients and 18 / 62 (29%) of usual-care patients, with a relative risk of 0.40 (95% CI = 0.18-0.89). Despite this reduction in delirium, length of stay did not significantly differ between intervention and usual-care groups (median +/- interquartile range = 5 +/- 2 days in both groups), likely because protocols and pathways predetermined length of stay. In subgroup analyses, geriatrics consultation was most effective in reducing delirium in patients without prefracture dementia or activities of daily living (ADL) functional impairment. CONCLUSIONS: Proactive geriatrics consultation was successfully implemented with good adherence after hip-fracture repair. Geriatrics consultation reduced delirium by over one-third, and reduced severe delirium by over one-half. Our trial provides strong preliminary evidence that proactive geriatrics consultation may play an important role in the acute hospital management of hip-fracture patients.

Delirium is independently associated with poor functional recovery after hip fracture.

OBJECTIVE: To evaluate the role of delirium in the natural history of functional recovery after hip fracture surgery, independent of prefracture status. DESIGN: Prospective cohort study. SETTING: Orthopedic surgery service at a large academic tertiary hospital, with follow-up extending into rehabilitation hospitals, nursing homes, and the community. PARTICIPANTS: One hundred twenty-six consenting subjects older than 65 years (mean age 79 +/- 8 years, 79% women) admitted emergently for surgical repair of hip fracture. MEASUREMENTS: Detailed assessment at enrollment to ascertain prefracture status through interviews with the patient and designated proxy and review of the medical record. Interviews included administration of standardized instruments (Activities of Daily Living (ADL) Scale, Blessed Dementia Rating Scale, Delirium Symptom Interview) and assessment of ambulation, and prefracture living situation. Medical comorbidity, the nature of the hip fracture, and the surgical repair were obtained from the medical record. All subjects underwent daily interviews for the duration of the hospitalization, including the Mini-Mental State Examination and Delirium Symptom Interview, and delirium was diagnosed using the Confusion Assessment Methods algorithm. Patients and proxies were recontacted 1 and 6 months after fracture, and underwent interviews similar to those at enrollment to determine death, persistent delirium, decline in ADL function, decline in ambulation, or new nursing home placement. RESULTS: Delirium occurred in 52/126 (41%) of patients, and persisted in 20/52 (39%) at hospital discharge, 15/52 (32%) at 1 month, and 3/52 (6%) at 6 months. Patients aged 80 years or older, and those with prefracture cognitive impairment, ADL functional impairment, and high medical comorbidity were more likely to develop delirium. However, after adjusting for these factors, delirium was still significantly associated with outcomes indicative of poor functional recovery 1 month after hip fracture: ADL decline (odds ratio (OR) = 2.6; 95% confidence interval (95% CI), 1.1- 6.1), decline in ambulation (OR = 2.6; 95% CI, 1.03-6.5), and death or new nursing home placement (OR = 3.0; 95% CI, 1.1-8.4). Patients whose delirium persisted at 1 month had worse outcomes than those whose delirium had resolved. CONCLUSIONS: Delirium is common, persistent, and independently associated with poor functional recovery 1 month after hip fracture even after adjusting for prefracture frailty. Further research is necessary to identify the mechanisms by which delirium contributes to poor functional recovery, and to determine whether interventions designed to prevent or reduce delirium can improve recovery after hip fracture.

Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery.

BACKGROUND: Cardiac complications are important causes of morbidity after noncardiac surgery. The purpose of this prospective cohort study was to develop and validate an index for risk of cardiac complications. METHODS AND RESULTS: We studied 4315 patients aged > or = 50 years undergoing elective major noncardiac procedures in a tertiary-care teaching hospital. The main outcome measures were major cardiac complications. Major cardiac complications occurred in 56 (2%) of 2893 patients assigned to the derivation cohort. Six independent predictors of complications were identified and included in a Revised Cardiac Risk Index: high-risk type of surgery, history of ischemic heart disease, history of congestive heart failure, history of cerebrovascular disease, preoperative treatment with insulin, and preoperative serum creatinine >2.0 mg/dL. Rates of major cardiac complication with 0, 1, 2, or > or = 3 of these factors were 0.5%, 1.3%, 4%, and 9%, respectively, in the derivation cohort and 0.4%, 0.9%, 7%, and 11%, respectively, among 1422 patients in the validation cohort. Receiver operating characteristic curve analysis in the validation cohort indicated that the diagnostic performance of the Revised Cardiac Risk Index was superior to other published risk-prediction indexes. CONCLUSIONS: In stable patients undergoing nonurgent major noncardiac surgery, this index can identify patients at higher risk for complications. This index may be useful for identification of candidates for further risk stratification with noninvasive technologies or other management strategies, as well as low-risk patients in whom additional evaluation is unlikely to be helpful.

Factors associated with unplanned hospital readmission among patients 65 years of age and older in a Medicare managed care plan.

PURPOSE: Unplanned hospital readmission within 30 days of discharge is considered a "sentinel event" for poor quality. Patients at high risk for this adverse event could be targeted for interventions designed to reduce their risk of readmission. The purpose of this study was to identify patient characteristics and risk factors at discharge associated with unplanned readmission within 30 days of hospital discharge. SUBJECTS AND METHODS: We performed a matched case-control study among patients in a Medicare managed care plan who had been admitted to an academic hospital. The cases were patients aged 65 years or older who were urgently or emergently readmitted to the hospital within 30 days of discharge. One control patient who was not readmitted within 30 days was matched to each case by principal diagnosis. The medical records of the first admission of the cases and the admission of the controls underwent review (blinded to case-control status) to determine the patient's baseline demographic characteristics, comorbid conditions, previous health care utilization, and functional status. The records were also reviewed to assess risk factors on discharge, including clinical instability, inability to ambulate and feed, mental status changes, number of discharge medications, and discharge disposition. RESULTS: Five factors were independently associated (P < 0.05) with unplanned readmission within 30 days. These included four baseline patient characteristics: age 80 years or older [odds ratio = 1.8; 95% confidence interval (CI), 1.02-3.2], previous admission within 30 days (odds ratio = 2.3; 95% CI, 1.2-4.6), five or more medical comorbidities (odds ratio = 2.6; 95% CI, 1.5-4.7), and history of depression (odds ratio = 3.2; 95% CI, 1.4-7.9); and one discharge factor: lack of documented patient or family education (odds ratio = 2.3; 95% CI, 1.2-4.5). CONCLUSIONS: If validated, these factors may identify patients at high risk of readmission. They suggest that interventions, such as improved discharge education programs, may reduce unplanned readmission.

Atrial natriuretic peptide and the development of congestive heart failure in the oldest old: a seven-year prospective study.

BACKGROUND: Atrial natriuretic peptide (ANP) levels are elevated in symptomatic heart failure and correlate with invasively measured left heart pressures. OBJECTIVE: To examine the association between plasma ANP level and the subsequent development of congestive heart failure (CHF) in older subjects with no history of CHF. DESIGN: A 7-year, prospective, blinded, cohort study. SETTING: A life care facility in Boston, Massachusetts. PARTICIPANTS: Two hundred fifty-six frail older subjects (mean age 88 +/- 7) with no history of CHF at study entry. MAIN OUTCOME MEASURE: Clinical episodes of CHF with confirmatory chest roentgenogram findings. Cox proportional hazard analyses were performed to examine the relationship between ANP levels and the development of CHF while controlling for 19 clinical, physical, and laboratory parameters. A Kaplan-Meier estimator (log-rank test) was used to determine if the development of CHF differed by tertile of ANP. RESULTS: During the follow-up period, 32% of the cohort developed CHF. The mean ANP level in the CHF group was 95 pmol/L +/- 11 pmol/L versus 60 pmol/L +/- 5 pmol/L in the no CHF group (two tailed t test P = .005). On multivariate analysis, a high ANP level was found to be associated significantly (P = .01) with the development of CHF. CONCLUSIONS: There is a statistically significant association between ANP level and the subsequent development of CHF in frail older individuals with no history of CHF.

The association of intraoperative factors with the development of postoperative delirium.

PURPOSE: To examine the association of intraoperative factors, including route of anesthesia, hemodynamic complications, and blood loss, with the development of postoperative delirium. PATIENTS AND METHODS: We studied 1,341 patients 50 years of age and older admitted for major elective noncardiac surgery at an academic medical center. Data on route of anesthesia, intraoperative hypotension, bradycardia and tachycardia, blood loss, number of blood transfusions, and lowest postoperative hematocrit were obtained from the medical record. Delirium was diagnosed by using daily interviews with the Confusion Assessment Method, as well as from the medical record and the hospital's nursing intensity index. RESULTS: Postoperative delirium occurred in 117 (9%) patients. Route of anesthesia and intraoperative hemodynamic complications were not associated with delirium. Delirium was associated with greater intraoperative blood loss, more postoperative blood transfusions, and postoperative hematocrit <30%. After adjusting for preoperative risk factors, postoperative hematocrit <30% was associated with an increased risk of delirium (odds ratio = 1.7, 95% confidence interval 1.1-2.7). CONCLUSIONS: Further study is required to determine whether transfusion to keep postoperative hematocrit above 30% can reduce the incidence of postoperative delirium.

Diagnosing delirium by telephone.

To determine whether delirium can be diagnosed by telephone, we interviewed 41 subjects aged 65 years or older 1 month after repair of hip fracture, first by telephone and then face-to-face. Interviews included the modified telephone Mini-Mental State Examination and the Delirium Symptom Interview. Delirium was diagnosed using the Confusion Assessment Method diagnostic algorithm, and the telephone results were compared with the face-to-face results (the "gold standard"). Of 41 subjects, 6 were delirious by face-to-face assessment; all 6 were delirious by telephone (sensitivity 1.00). Of 35 patients not delirious by face-to-face assessment, 33 patients were not delirious by telephone (specificity = 0.94). We conclude that telephone interviews can effectively rule out delirium, but the positive diagnosis should be confirmed by a face-to-face assessment, especially in populations with a low prevalence of delirium.

Delirium in the elderly. Optimal management.

Delirium is common, morbid and costly, especially among hospitalised elderly patients. Nonetheless, it remains under-recognised and often poorly managed. This article summarises the 5 key steps in the optimal management of delirium. The first step is to precisely define the syndrome of delirium, using key features described in the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) [DSM-IV] or the Confusion Assessment Method. Key features include an acute onset of mental status change, fluctuating course, the presence of inattention, and either disorganised thinking or an altered level of of consciousness. The second step involves the identification of patients at high risk of delirium before it develops, so that preventive measures can be implemented. Risk factors for delirium include advanced age, dementia, impaired functional status, chronic comorbidities and medications, and the severity of the acute illness or surgery. The third step is improved recognition of delirium. Very often, the presence of delirium is neither diagnosed nor properly documented in the medical record. The fourth step is to appropriately evaluate the delirious patient to assess all important contributors to the syndrome. This evaluation will usually involve a careful history, medication review, physical examination and selected laboratory testing. The fifth, and most important, step is the management of the delirious patient. The key elements of management are treating the primary condition(s) leading to delirium, removing all treatable contributing factors, maintaining behavioural control, and supporting the patient and their family.

Supraventricular arrhythmia in patients having noncardiac surgery: clinical correlates and effect on length of stay.

BACKGROUND: Few recent data are available on risk factors for perioperative supraventricular arrhythmia (SVA) after noncardiac surgery or on the effect of SVA on clinical outcomes. OBJECTIVE: To determine the incidence, clinical correlates, and effect on length of stay of perioperative SVA in patients having major noncardiac surgery. DESIGN: Prospective cohort study. SETTING: Urban tertiary care teaching hospital. PARTICIPANTS: 4181 patients 50 years of age or older who had major, nonemergency, noncardiac procedures and were in sinus rhythm at the preoperative evaluation. MEASUREMENTS: Preoperative clinical data, postoperative enzyme data, serial electrocardiograms, and clinical outcomes were collected prospectively. Outcomes were 1) SVA that persisted or led to treatment and 2) increase in length of stay attributable to SVA. RESULTS: Perioperative SVA occurred in 317 patients (7.6%); it occurred in 83 patients (2.0%) during surgery and in 256 (6.1%) after surgery. Independent preoperative correlates of SVA were male sex (odds ratio [OR], 1.3 [95% CI, 1.0 to 1.7]), age 70 years or older (OR, 1.3 [CI, 1.0 to 1.7]), significant valvular disease (OR, 2.1 [CI, 1.2 to 3.6]), history of SVA (OR, 3.4 [CI, 2.4 to 4.8]) or asthma (OR, 2.0 [CI, 1.3 to 3.1]), congestive heart failure (OR, 1.7 [CI, 1.1 to 2.7]), premature atrial complexes on preoperative electrocardiography (OR, 2.1 [CI, 1.3 to 3.4]), American Society of Anesthesiologists class III or IV (OR, 1.4 [CI, 1.1 to 1.9]), and type of procedure: abdominal aortic aneurysm (OR, 3.9 [CI, 2.4 to 6.3]) or abdominal (OR, 2.5 [CI, 1.7 to 3.6]), vascular (OR, 1.6 [CI, 1.1 to 2.4]), and intrathoracic (OR, 9.2 [CI, 6.7 to 13]) procedures. Among patients who had intrathoracic surgery, those receiving digoxin were at lower risk (OR, 0.2 [CI, 0.04 to 0.8]) for SVA than those not receiving digoxin. Patients with perioperative acute cardiac and noncardiac events had high relative risks for SVA. Supraventricular arrhythmia was associated with a 33% increase in length of stay after adjustment for other clinical data (P < 0.001). CONCLUSIONS: In this cohort, SVA was common after noncardiac surgery and was associated with prolonged length of stay.

The impact of postoperative pain on the development of postoperative delirium.

UNLABELLED: We performed a prospective observational study to examine the role of postoperative pain and its treatment on the development of postoperative delirium. Pain was measured in direct patient interviews using a visual analog scale (VAS) and was assessed for pain at rest, pain with movement, and maximal pain over the previous 24 h. Postoperative delirium was diagnosed during these interviews by using the confusion assessment method (CAM) and/or by using data from the medical record and the hospital's nursing intensity index. The method of postoperative analgesia, type of opioid, and cumulative opioid dose were also recorded. After controlling for known preoperative risk factors for delirium (age, alcohol abuse, cognitive function, physical function, serum chemistries, and type of surgery), higher pain scores at rest was associated with an increased risk of delirium over the first 3 postoperative days (adjusted risk ratio 1.20, P = 0.04). Pain with movement and maximal pain were not associated with delirium. Method of postoperative analgesia, type of opioid, and cumulative opioid dose were not associated with an increased risk of delirium. We conclude that more effective control of postoperative pain reduces the incidence of postoperative delirium. IMPLICATIONS: We performed daily interviews in a large population of patients undergoing noncardiac surgery to measure their level of pain and development of delirium. We found an association between higher pain levels at rest and the development of delirium. Our results suggest that better control of postoperative pain may reduce this serious complication.

Atrial natriuretic peptide level contributes to a model of future mortality in the oldest old.

OBJECTIVES: To determine if atrial natriuretic peptide (ANP) level is associated with mortality in the oldest old and to develop a comprehensive model of mortality in the oldest old using clinical and laboratory parameters. DESIGN: Prospective cohort study with 7 years of follow-up. SETTING: A 725-bed life care facility. PARTICIPANTS: 282 frail older individuals (mean age 88, range 70-102). MEASUREMENTS: Variables measured included age, gender, Charlson Comorbidity Index, functional measurements, weight, blood pressure, and multiple laboratory variables, including ANP. Main outcome measurement was death. RESULTS: Eighty-four percent (237/282) of subjects died during the 7-year follow-up period. On univariate analysis, the risk ratio (RR) for ANP tertile was 1.28. On bivariate analysis, adjusting for the development of congestive heart failure, the RR was 1.22. On multivariate analysis, the following variables were associated with mortality: ANP tertile (RR 1.24), age (RR 1.04), female gender (RR 0.43), Charlson Comorbidity Index score (RR 1.13), mentation score (RR 1.27), BUN/Cr ratio (RR 1.04), albumin level (RR 0.63), and hemoglobin level (RR 0.84). CONCLUSIONS: ANP level and other variables are independent risk factors for mortality in frail individuals. ANP level may indicate homeostatic failure to adapt to fluid volume changes or may reflect subclinical heart disease. ANP level contributes to a multivariate model of mortality in frail older individuals.

Health-related quality of life after elective surgery: measurement of longitudinal changes.

OBJECTIVE: To examine the responsiveness of the 36-Item Short Form Health Survey (SF-36) to clinical changes in three surgical groups and to study how health-related quality of life (HRQL) changes with time among patients who undergo total hip arthroplasty, thoracic surgery for treatment of non-small-cell lung cancer, or abdominal aortic aneurysm (AAA) repair. DESIGN: Prospective cohort study with serial evaluations of HRQL preoperatively and at 1, 6, and 12 months after surgery. SETTING: University tertiary care hospital. PATIENTS: Of 528 patients, more than 50 years of age, who were admitted for these elective procedures, 454 (86%) provided preoperative health status data and are members of the study cohort. At 12 months after surgery, 439 (93%) of the cohort was successfully contacted and 390 (90%) provided follow-up interviews. MEASUREMENTS AND MAIN RESULTS: The Medical Outcomes Study SF-36, the Specific Activity Scale, five validated health transition questions, and a 0 to 100 scale measure of global health were used to assess changes in health status at 1, 6, and 12 months after surgery. Change in health status as measured by the SF-36 demonstrated that physical function and role limitations due to physical health problems were worse 1 month after these three surgeries. However, by 6 months after surgery, most patients experienced significant gains in the majority of the dimensions of health, and these gains were sustained at 12 months after surgery. Longitudinal changes in the SF-36 were positively associated with responses to the five health transition questions, to changes on the Specific Activity Scale and global health rating question, and to clinical parameters for persons who had AAA repair. These findings indicate that the SF-36 has evidence of validity and is responsive to expected changes in HRQL after elective surgery for these procedures. CONCLUSIONS: For the total hip arthroplasty patients, responsiveness was greatest for the SF-36 scales that measure physical constructs. However, for the two other procedures and at various points of recovery, significant changes were observed for all eight subscales, suggesting that responsiveness was dependent on the type of surgery and the timing of follow-up, and that multidimensional measures are needed to fully capture changes in HRQL after surgery.