Early Opioid Use and Postoperative Delirium Following Open Abdominal Aortic Aneurysm Repair.

BACKGROUND: Postoperative delirium is a common complication following open abdominal aortic aneurysm repair (OAR). Opioids have been found to contribute to delirium, especially at higher doses. This study assessed the impact of early postoperative opioid analgesia on postoperative delirium incidence and time to onset. We hypothesized that higher early postoperative opioid utilization would be associated with increased postoperative delirium incidence. METHODS: This was a retrospective analysis of OAR cases at a single quaternary care center from years 2012-2020. The primary exposure was oral morphine equivalents use (OME), calculated for postoperative days 1-7. A cut point analysis using a receiver operator curve for postoperative delirium determined the threshold for high OME (OME>37 mg). The primary outcome was postoperative delirium incidence identified via chart review. Multivariable logistic regression was performed for postoperative delirium and adjusted for covariates meeting P < 0.1 on bivariate analysis. RESULTS: Among 194 OAR cases, 67 (35%) developed postoperative delirium with median time to onset of 3 days (IQR = 2-6). Patients with postoperative delirium were older (74 years vs. 69 years), more frequently presented with symptomatic AAA (47% vs. 27%) and had a higher proportion of comorbidities (all P < 0.05). Cases with high OME utilization on postoperative day 1 (55%) were younger (69 vs. 73 years), less frequently had an epidural (46% vs. 77%), and more frequently developed delirium (42% vs. 25%, all P < 0.05). Epidural use was associated with a significant decrease in OME utilization on postoperative day 1 (33 vs. 83, P < 0.01). Postoperative delirium onset was later in those with high OME use (4 vs. 2 days, P = 0.04). On multivariable analysis, high OME remained associated with postoperative delirium (Table II). CONCLUSIONS: High opioid utilization on postoperative day 1 is associated with increased postoperative delirium and epidural along with acetaminophen use reduced opioid utilization. Future study should examine the impact of opioid reduction strategies on outcomes after major vascular surgery.

Predictors of amputation-free survival and wound healing after infrainguinal bypass with alternative conduits.

OBJECTIVE: Inadequate vein quality or prior harvest precludes use of autologous single segment greater saphenous vein (ssGSV) in many patients with chronic limb-threatening ischemia (CLTI). Predictors of patient outcome after infrainguinal bypass with alternative (non-ssGSV) conduits are not well-understood. We explored whether limb presentation, bypass target, and conduit type were associated with amputation-free survival (AFS) after infrainguinal bypass using alternative conduits. METHODS: A single-center retrospective study (2013-2020) was conducted of 139 infrainguinal bypasses performed for CLTI with cryopreserved ssGSV (cryovein) (n = 71), polytetrafluoroethylene (PTFE) (n = 23), or arm/spliced vein grafts (n = 45). Characteristics, Wound, Ischemia, and foot Infection (WIfI) stage, and outcomes were recorded. Multivariable Cox proportional hazards and classification and regression tree analysis modeled predictors of AFS. RESULTS: Within 139 cases, the mean age was 71 years, 59% of patients were male, and 51% of cases were nonelective. More patients undergoing bypass with cryovein were WIfI stage 4 (41%) compared with PTFE (13%) or arm/spliced vein (27%) (P = .04). Across groups, AFS at 2 years was 78% for spliced/arm, 79% for PTFE, and 53% for cryovein (adjusted hazard ratio for cryovein, 2.5; P = .02). Among cases using cryovein, classification and regression tree analysis showed that WIfI stage 3 or 4, age >70 years, and prior failed bypass were predictive of the lowest AFS at 2 years of 36% vs AFS of 58% to 76% among subgroups with less than two of these factors. Although secondary patency at 2 years was worse in the cryovein group (26% vs 68% and 89% in arm/spliced and PTFE groups; P < .01), in patients with tissue loss there was no statistically significant difference in wound healing in the cryovein group (72%) compared with other bypass types (72% vs 87%, respectively; P = .12). CONCLUSIONS: In patients with CLTI lacking suitable ssGSV, bypass with autogenous arm/spliced vein or PTFE has superior AFS compared with cryovein, although data were limited for PTFE conduits for distal targets. Despite poor patency with cryovein, wound healing is achieved in a majority of cases, although it should be used with caution in older patients with high WIfI stage and prior failed bypass, given the low rates of AFS.

Risk factors and associated outcomes of postoperative delirium after open abdominal aortic aneurysm repair.

OBJECTIVE: Open abdominal aortic aneurysm repair (OAR) is a major vascular procedure that incurs a large physiologic demand, increasing the risk for complications such as postoperative delirium (POD). We sought to characterize POD incidence, identify delirium risk factors, and evaluate the effect of delirium on postoperative outcomes. We hypothesized that POD following OAR would be associated with increased postoperative complications and resource utilization. METHODS: This was a retrospective study of all OAR cases from 2012 to 2020 at a single tertiary care center. POD was identified via a validated chart review method based on key words and Confusion Assessment Method assessments. The primary outcome was POD, and secondary outcomes included length of stay, non-home discharge, 90-day mortality, and 1-year survival. Bivariate analysis as appropriate to the data was used to assess the association of delirium with postoperative outcomes. Multivariable binary logistic regression was used to identify risk factors for POD and Cox regression for variables associated with worse 1-year survival. RESULTS: Overall, 198 OAR cases were included, and POD developed in 34% (n = 67). Factors associated with POD included older age (74 vs 69 years; P < .01), frailty (50% vs 28%; P < .01), preoperative dementia (100% vs 32%; P < .01), symptomatic presentation (47% vs 27%; P < .01), preoperative coronary artery disease (44% vs 28%; P = .02), end-stage renal disease (89% vs 32%; P < .01) and Charlson Comorbidity Index score >4 (42% vs 26%; P = .01). POD was associated with 90-day mortality (19% vs 5%; P < .01), non-home discharge (61% vs 30%; P < .01), longer median hospital length of stay (14 vs 8 days; P < .01), longer median intensive care unit length of stay (6 vs 3 days; P < .01), postoperative myocardial infarction (7% vs 2%; P = .045), and postoperative pneumonia (19% vs 8%; P = .01). On multivariable analysis, risk factors for POD included older age, history of end-stage renal disease, lack of epidural, frailty, and symptomatic presentation. A Cox proportional hazards model revealed that POD was associated with worse survival at 1 year (hazard ratio, 3.8; 95% confidence interval, 1.6-9.0; P = .003). CONCLUSIONS: POD is associated with worse postoperative outcomes and increased resource utilization. Future studies should examine the role of improved screening, implementation of delirium prevention bundles, and multidisciplinary care for the most vulnerable patients undergoing OAR.

Clinical Predictors and Outcomes Associated with Postoperative Delirium Following Infrainguinal Bypass Surgery.

BACKGROUND: Post-operative delirium (POD) is common yet often underdiagnosed following vascular surgery. Elderly patients with advanced peripheral artery disease may be at particular risk for POD yet understanding of the clinical predictors and impact of POD is incomplete. We sought to identify POD predictors and associated resource utilization after infrainguinal lower extremity bypass. METHODS: This single center retrospective analysis included all infrainguinal bypass cases performed for peripheral arterial disease from 2012-2020. The primary outcome was inpatient POD. Delirium sequelae were also evaluated. Key secondary outcomes were length of stay, nonhome discharge, readmission, 30-day amputation, post-operative myocardial infarction, mortality, and 2-year survival. Regression analysis was used to evaluate risk factors for delirium in addition to association with 2-year survival and amputation free survival. RESULTS: Among 420 subjects undergoing infrainguinal lower extremity bypass, 105 (25%) developed POD. Individuals with POD were older and more likely to have non-elective surgery (P < 0.05). On multivariable analysis, independent predictors of POD were age 60-89 years old, chronic limb threatening ischemia, female sex, and nonelective procedure. Consultations for POD took place for 25 cases (24%); 13 (52%) were with pharmacists, and only 4 (16%) resulted in recommendations. The average length of stay for those with POD was higher (17 days vs. 9 days; P < 0.001). POD was associated with increased non-home discharge (61.8% vs. 22.1%; P < 0.001), 30-day major amputation (6.7% vs. 1.6%; P < 0.01), 30-day postoperative myocardial infarction (11.4% vs. 4.1%; P < 0.01), and 90-day mortality (7.6% vs. 2.9%; P = 0.03). Survival at 2 years was lower in those with delirium (89% vs. 75%; P < 0.001). In a Cox proportional hazards model, delirium was independently associated with decreased survival (HR = 2.0; 95% CI = 1.15-3.38; P = 0.014) and decreased major-amputation free survival (HR = 1.9; 95% CI = 1.18-2.96; P = 0.007). CONCLUSIONS: POD is common following infrainguinal lower extremity bypass and is associated with other adverse post-operative outcomes and increased resource utilization, including increased hospital length of stay, nonhome discharge, and worse 2-year survival. Future studies should evaluate the role of routine multidisciplinary care for high-risk patients to improve perioperative outcomes for vulnerable older adults undergoing infrainguinal lower extremity bypass.