Postoperative Delirium and Postoperative Cognitive Dysfunction: Overlap and Divergence.

BACKGROUND: Postoperative delirium and postoperative cognitive dysfunction share risk factors and may co-occur, but their relationship is not well established. The primary goals of this study were to describe the prevalence of postoperative cognitive dysfunction and to investigate its association with in-hospital delirium. The authors hypothesized that delirium would be a significant risk factor for postoperative cognitive dysfunction during follow-up. METHODS: This study used data from an observational study of cognitive outcomes after major noncardiac surgery, the Successful Aging after Elective Surgery study. Postoperative delirium was evaluated each hospital day with confusion assessment method-based interviews supplemented by chart reviews. Postoperative cognitive dysfunction was determined using methods adapted from the International Study of Postoperative Cognitive Dysfunction. Associations between delirium and postoperative cognitive dysfunction were examined at 1, 2, and 6 months. RESULTS: One hundred thirty-four of 560 participants (24%) developed delirium during hospitalization. Slightly fewer than half (47%, 256 of 548) met the International Study of Postoperative Cognitive Dysfunction-defined threshold for postoperative cognitive dysfunction at 1 month, but this proportion decreased at 2 months (23%, 123 of 536) and 6 months (16%, 85 of 528). At each follow-up, the level of agreement between delirium and postoperative cognitive dysfunction was poor (kappa less than .08) and correlations were small (r less than .16). The relative risk of postoperative cognitive dysfunction was significantly elevated for patients with a history of postoperative delirium at 1 month (relative risk = 1.34; 95% CI, 1.07-1.67), but not 2 months (relative risk = 1.08; 95% CI, 0.72-1.64), or 6 months (relative risk = 1.21; 95% CI, 0.71-2.09). CONCLUSIONS: Delirium significantly increased the risk of postoperative cognitive dysfunction in the first postoperative month; this relationship did not hold in longer-term follow-up. At each evaluation, postoperative cognitive dysfunction was more common among patients without delirium. Postoperative delirium and postoperative cognitive dysfunction may be distinct manifestations of perioperative neurocognitive deficits.

Trajectory of Functional Recovery After Postoperative Delirium in Elective Surgery.

OBJECTIVE: To describe functional recovery after elective surgery and to determine whether improvements differ among individuals who develop delirium. BACKGROUND: No large studies of older adults have investigated whether delirium influences the trajectory of functional recovery after elective surgery. The prospective observational study assessed this association among 566 individuals aged 70 years and older. METHODS: Patients undergoing major elective surgery were assessed daily while in hospital for presence and severity of delirium using the Confusion Assessment Method, and their functional recovery was followed for 18 months thereafter. The Activities of Daily Living and Instrumental Activities of Daily Living Scales and the Physical Component Summary of the Short Form-12 were obtained before surgery and at 1, 2, 6, 12, and 18 months. A composite index (standard deviation 10, minimally clinically significant difference 2) derived from these scales was then analyzed using mixed-effects regression. RESULTS: Mean age was 77 years; 58% of participants were women and 24% developed postoperative delirium. Participants with delirium demonstrated lesser functional recovery than their counterparts without delirium; at 1 month, the covariate-adjusted mean difference on the physical function composite was -1.5 (95% confidence interval -3.3, -0.2). From 2 to 18 months, the corresponding difference was -1.8 (95% confidence interval -3.2, -0.3), an effect comparable with the minimally clinically significant difference. CONCLUSIONS: Delirium was associated with persistent and clinically meaningful impairment of functional recovery, to 18 months. Use of multifactorial preventive interventions for patients at high risk for delirium and tailored transitional care planning may help to maximize the functional benefits of elective surgery.

Bone microarchitecture, biomechanical properties, and advanced glycation end-products in the proximal femur of adults with type 2 diabetes.

Skeletal fragility is a major complication of type 2 diabetes mellitus (T2D), but there is a poor understanding of mechanisms underlying T2D skeletal fragility. The increased fracture risk has been suggested to result from deteriorated bone microarchitecture or poor bone quality due to accumulation of advanced glycation end-products (AGEs). We conducted a clinical study to determine whether: 1) bone microarchitecture, AGEs, and bone biomechanical properties are altered in T2D bone, 2) bone AGEs are related to bone biomechanical properties, and 3) serum AGE levels reflect those in bone. To do so, we collected serum and proximal femur specimens from T2D (n = 20) and non-diabetic (n = 33) subjects undergoing total hip replacement surgery. A section from the femoral neck was imaged by microcomputed tomography (microCT), tested by cyclic reference point indentation, and quantified for AGE content. A trabecular core taken from the femoral head was imaged by microCT and subjected to uniaxial unconfined compression tests. T2D subjects had greater HbA1c (+23%, p ≤ 0.0001), but no difference in cortical tissue mineral density, cortical porosity, or trabecular microarchitecture compared to non-diabetics. Cyclic reference point indentation revealed that creep indentation distance (+18%, p ≤ 0.05) and indentation distance increase (+20%, p ≤ 0.05) were greater in cortical bone from T2D than in non-diabetics, but no other indentation variables differed. Trabecular bone mechanical properties were similar in both groups, except for yield stress, which tended to be lower in T2D than in non-diabetics. Neither serum pentosidine nor serum total AGEs were different between groups. Cortical, but not trabecular, bone AGEs tended to be higher in T2D subjects (21%, p = 0.09). Serum AGEs and pentosidine were positively correlated with cortical and trabecular bone AGEs. Our study presents new data on biomechanical properties and AGEs in adults with T2D, which are needed to better understand mechanisms contributing to diabetic skeletal fragility.

Comparison of Frailty Measures as Predictors of Outcomes After Orthopedic Surgery.

OBJECTIVES: To apply the Frailty Phenotype (FP) and Frailty Index (FI) before major elective orthopedic surgery to categorize frailty status and assess associations with postoperative outcomes. DESIGN: Prospective cohort study. SETTING: Two tertiary hospitals in Boston, Massachusetts. PARTICIPANTS: Individuals aged 70 and older undergoing scheduled orthopedic surgery enrolled in the Successful Aging after Elective Surgery (SAGES) Study (N = 415). MEASUREMENTS: Preoperative evaluation included assessment of frailty using the FP and FI. The weighted kappa statistic was used to determine concordance between the two frailty measures and multivariable modeling to determine associations between each measure and postoperative complications, postoperative length of stay (LOS) of longer than 5 days, discharge to postacute institutional care (PAC), and 300 day readmission. RESULTS: Frailty was highly prevalent (FP, 35%; FI, 41%). There was moderate concordance between the FP and FI (κ = 0.42, 95% confidence interval (CI) 0.36-0.49). When using the FP, being prefrail predicted greater risk of complications (relative risk (RR) = 1.6, 95% CI = 1.1-2.1) and discharge to PAC (RR = 1.8, 95% CI = 1.2-2.9) than being robust, and being frail predicted more complications (RR = 1.7, 95% CI = 1.1-2.1), LOS longer than 5 days (RR = 3.1, 95% CI = 1.1-8.8), and discharge to PAC (RR = 2.3 95% CI = 1.4-3.7). When using FI, being prefrail predicted LOS longer than 5 days (RR = 2.1, 95% CI = 1.0-4.8) and discharge to PAC (RR = 1.5, 95% CI = 1.4-2.1), as did being frail (RR = 1.9, 95% CI = 1.4-2.5; RR = 3.1, 95% CI = 1.4-6.8, respectively). The other outcomes were not significantly associated with frailty status. CONCLUSION: FP and FI predict postoperative outcomes after major elective orthopedic surgery and should be considered for preoperative risk stratification.

Coloarticular fistula: A rare complication of revision total hip arthroplasty.

Fistula formation between bowel and total hip arthroplasty or revision arthroplasty hardware is rare. We present a case of a 78-year-old woman with protrusio of left hip arthroplasty and acetabular reconstruction hardware that caused direct perforation of the sigmoid colon and fistula formation between the sigmoid colon and the left hip joint. The patient underwent several joint debridements, sigmoid colectomy, and removal of all orthopedic hardware; she ultimately died after two prolonged hospitalizations.