Exploration of a Multi-Parameter Technology for Pain Assessment in Postoperative Patients After Cardiac Surgery in the Intensive Care Unit: The Nociception Level Index (NOL)TM.

INTRODUCTION: The aim of this study was to explore the use of a multi-parameter technology, the Nociception Level (NOL) index (Medasense Biometrics Ltd, Ramat Gan, Israel), for pain assessment in postoperative awake patients after cardiac surgery during non-nociceptive and nociceptive procedures in the intensive care unit (ICU). MATERIALS AND METHODS: A prospective cohort repeated-measures design was used. Patients were included if they were in the ICU after undergoing cardiac surgery and if they could self-report their pain. A non-invasive probe was placed on the patient's finger for the continuous monitoring of the NOL index. Patients' self-reports of pain and anxiety (0-10 Numeric Rating Scale or NRS), and behavioral scores with the Critical-Care Pain Observation Tool (CPOT) were obtained before and during a non-nociceptive procedure (ie, non-invasive blood pressure [NIBP] using cuff inflation), and before, during and after a nociceptive procedure (ie, chest tube removal [CTR]) for a total of five time points. Non-parametric tests were used to compare scores at different time points, and receiver operating characteristic curve analysis was performed. RESULTS: Fifty-four patients were included in the analysis. The NOL index, pain and anxiety scores were significantly higher during CTR compared to rest and NIBP (p < 0.001). During CTR, the NOL was associated with self-reported pain intensity and unpleasantness but not with anxiety and CPOT scores. The NOL showed a modest performance in detecting pain (NRS ≥1 and ≥5) in this sample with sensitivity and specificity ranging from 61% to 85%. CONCLUSION: The NOL index was able to discriminate between a non-nociceptive and a nociceptive procedure and was associated with self-reported pain. Further validation testing of the NOL is necessary in a heterogeneous sample of ICU patients.

Cell Seeding on UV-C-Treated 3D Polymeric Templates Allows for Cost-Effective Production of Small-Caliber Tissue-Engineered Blood Vessels.

There is a strong clinical need to develop small-caliber tissue-engineered blood vessels for arterial bypass surgeries. Such substitutes can be engineered using the self-assembly approach in which cells produce their own extracellular matrix (ECM), creating a robust vessel without exogenous material. However, this approach is currently limited to the production of flat sheets that need to be further rolled into the final desired tubular shape. In this study, human fibroblasts and smooth muscle cells were seeded directly on UV-C-treated cylindrical polyethylene terephthalate glycol-modified (PETG) mandrels of 4.8 mm diameter. UV-C treatment induced surface modification, confirmed by Fourier-transform infrared spectroscopy (FTIR) analysis, was necessary to ensure proper cellular attachment and optimized ECM secretion/assembly. This novel approach generated solid tubular conduits with high level of cohesion between concentric cellular layers and enhanced cell-driven circumferential alignment that can be manipulated after 21 days of culture. This simple and cost-effective mandrel-seeded approach also allowed for endothelialization of the construct and the production of perfusable trilayered tissue-engineered blood vessels with a closed lumen. This study lays the foundation for a broad field of possible applications enabling custom-made reconstructed tissues of specialized shapes using a surface treated 3D structure as a template for tissue engineering.

Cost of Cardiac Surgery in Frail Compared With Nonfrail Older Adults.

BACKGROUND: Frailty is a risk factor for mortality, morbidity, and prolonged length of stay after cardiac surgery, all of which are major drivers of hospitalization costs. The incremental hospitalization costs incurred in frail patients have yet to be elucidated. METHODS: Patients aged ≥ 60 years were evaluated for frailty before coronary artery bypass grafting or heart valve surgery at 2 academic centres between 2013 and 2015 as part of the McGill Frailty Registry. Total costs were summed from the date of the index surgery to the date of hospital discharge. Mutivariable linear regression was used to determine the association between preoperative frailty status and total costs after adjusting for conventional surgical risk factors. RESULTS: Among 235 patients included in the analysis, the median age was 73.0 years (interquartile range [IQR], 70.0-78.0 years) and 68 (29%) were women. The median cost was $32,742 (IQR, $23,221-$49,627) in 91 frail patients compared with $23,370 (IQR, $19,977-$29,705) in 144 nonfrail patients. Seven extreme-cost cases > $100,000 were identified, and all of the patients in these cases exhibited baseline frailty. In the multivariable model, total costs were independently associated with frailty (adjusted additional cost, $21,245; 95% confidence interval [CI], $12,418-$30,073; P < 0.001) and valve surgery (adjusted additional cost, $20,600; 95% CI, $9,661-$31,539; P < 0.001). CONCLUSIONS: Frailty is associated with a marked increase in hospitalization costs after cardiac surgery, an effect that persists after adjusting for age, sex, surgery type, and surgical risk score. Further efforts are needed to optimize care and resource use in this vulnerable population.

Derivation and Validation of Prognosis-Based Age Cutoffs to Define Elderly in Cardiac Surgery.

BACKGROUND: The age cutoff to define elderly is controversial in cardiac surgery, empirically ranging from ≥65 to ≥80 years. Beyond semantics, this has important implications as a starting point for clinical care pathways and inclusion in trials. We sought to characterize the relationship between age and adverse outcomes in patients undergoing cardiac surgery and to derive and validate prognosis-based age cutoffs. METHODS AND RESULTS: Six thousand five hundred seventy one consecutive adult patients undergoing cardiac surgery at 3 hospitals in the United States and Canada were included in the cohort. Logistic regression models and generalized additive models with thin-plate splines were fit to the data. The age distribution was 50 to 59 years in 1244 (18.9%), 60 to 69 years in 2144 (32.6%), 70 to 79 years in 2000 (30.4%), ≥80 years in 1183 (18.0%) patients. After controlling for sex and type of operation, the relationship between age and 30-day operative mortality was found to be nonlinear. Receiver operating characteristic analysis showed that the optimal cutoffs to identify older patients at higher risk of operative mortality were greater than 74, 78, and 75 years for isolated coronary bypass, isolated valve surgery, and coronary bypass plus valve surgery, respectively. These age cutoffs were validated in an independent cohort. CONCLUSIONS: The relationship between age and operative mortality is not linear, manifesting a steeper rise after age 75 for coronary bypass and approaching octogenarian age for isolated valve surgery. Rather than using arbitrary age cutoffs to define elderly, the outcomes-based cutoff of ≥75 years should be used to identify the population of older adults that has higher risk and may benefit from preoperative geriatric evaluation and optimization.

Risk factors for prolonged stay in the intensive care unit and on the ward after cardiac surgery.

BACKGROUND: Prolonged length of stay (LOS) after cardiac surgery has been associated with poor outcome and a considerable expenditure of health care resources. As our patient's demographics are changing, a continuing evaluation of the preoperative and intraoperative variables affecting LOS in the intensive care unit (ICU) and on the floor remains important. METHODS: This is a prospective study examining the determinants of prolonged LOS in 426 consecutive patients after cardiac surgery. Univariate and multivariate analyses were performed for an ICU stay > or =2 days and for a stay on the floor >7 days. Secondary outcome was the incidence of postoperative complications. RESULTS: Among all patients, 27.7% had a prolonged stay in the ICU. Univariate analysis revealed 13 perioperative variables that were significantly associated with prolonged stay. Independent predictors for extended ICU LOS included an ejection fraction <40% (RR 1.83; p = 0.04), high Parsonnet score (RR 2.23; p = 0.012), history of renal failure (RR 5.39; p = 0.001), and an emergency surgery (RR 2.43; p = 0.007). Furthermore, 30.5% of patients had an extended stay on the floor with female gender (RR 1.93; p = 0.009) and age (RR 2.55; p = 0.0001) being two independent risk factors. CONCLUSIONS: In this series of 426 consecutive patients, we have identified several perioperative risk factors associated with prolonged hospitalization that can help clinicians in their preoperative patient counseling, risk stratification, and selection. However, the most obvious use of these results is in allowing decision makers to implement specific strategies that would best allocate resources depending on the risk profile of cardiac patients.