Loss or Dilution-A New Diagnostic Method to Assess the Impact of Dilution on Standard Laboratory Parameters.

Intraoperative fluid therapy is regularly used in patients undergoing cardiac surgery procedures with cardiopulmonary bypass (CPB). Although fluid administration has several advantages, it unavoidably leads to hemodilution. The hemodilution may further influence the interpretation of concentration-based laboratory parameters like hemoglobin (Hgb), platelet count (PLT) or prothrombin time (PT). These all parameters are commonly used to guide blood product substitution. To assess the impact of dilution on these values, we performed a prospective observational study in 174 patients undergoing elective cardiac surgery. We calculated the total blood volume according to Nadler's formula, and fluid therapy was correlated with a newly developed dilution coefficient formula at the end of CPB. Intravenously applied fluids were measured from the beginning of the anesthesia (baseline, T0) and 15 min after the end of protamine infusion (end of CPB, T1). The amount of the administered volume (crystalloids or colloids) was calculated according to the percentage of the intravascular fluid effect, and intraoperative diuresis was further subtracted. The median blood volume increased by 148% in all patients at T1 compared to the calculated total blood volume at T0. This led to a dilution-dependent decrease of 38% in all three parameters (Hgb 24%, corrCoeff = 0.53; PLT 41%, corrCoeff = 0.68; PT 44%, corrCoeff = 0.54). The dilution-correlated decrease was significant for all parameters (p < 0.001), and the effect was independent from the duration of CPB. We conclude that the presented calculation-based approach could provide important information regarding actual laboratory parameters and may help in the guidance of the blood product substitution and potential transfusion thresholds. Further research on the impact of dilution and related decision-making for blood product substitution, including its impact on morbidity and mortality, is warranted.

Invasive Fungal Infections: The Early Killer after Liver Transplantation.

BACKGROUND: Liver transplantation is a standard of care and a life-saving procedure for end-stage liver diseases and certain malignancies. The evidence on predictors and risk factors for poor outcomes is lacking. Therefore, we aimed to identify potential risk factors for mortality and to report on overall 90-day mortality after orthotopic liver transplantation (OLT), especially focusing on the role of fungal infections. METHODS: We retrospectively reviewed medical charts of all patients undergoing OLT at a tertiary university center in Europe. RESULTS: From 299 patients, 214 adult patients who received a first-time OLT were included. The OLT indication was mainly due to tumors (42%, 89/214) and cirrhosis (32%, 68/214), including acute liver failure in 4.7% (10/214) of patients. In total, 8% (17/214) of patients died within the first three months, with a median time to death of 15 (1-80) days. Despite a targeted antimycotic prophylaxis using echinocandins, invasive fungal infections occurred in 12% (26/214) of the patients. In the multivariate analysis, patients with invasive fungal infections had an almost five times higher chance of death (HR 4.6, 95% CI 1.1-18.8; p = 0.032). CONCLUSIONS: Short-term mortality after OLT is mainly determined by infectious and procedural complications. Fungal breakthrough infections are becoming a growing concern. Procedural, host, and fungal factors can contribute to a failure of prophylaxis. Finally, invasive fungal infections may be a potentially modifiable risk factor, but the ideal perioperative antimycotic prophylaxis has yet to be determined.

Delayed Reconstruction after Major Head and Neck Cancer Resection: An Interdisciplinary Feasibility Study.

A single immediate reconstruction with free tissue transfer is the method of choice after major head and neck cancer (HNC) resection, but this is frequently associated with long operating hours. Considering regulatory working hour constraints, we investigated whether a two-staged reconstructive approach with temporary defect coverage by an artificial tissue substitute would be feasible. HNC patients underwent either immediate or delayed reconstruction after tumor resection. Patients with delayed reconstruction received preliminary reconstruction with an artificial tissue substitute followed by definitive microvascular reconstruction in a separate, second procedure. Of the 33 HNC patients, 13 received delayed reconstruction and 20 received immediate reconstruction. Total anesthesia time (714 vs. 1011 min; p < 0.002) and the total duration of hospital stay (34 ± 13 vs. 25 ± 6 days; p = 0.03) were longer in the delayed reconstruction group. Perioperative morbidity (p = 0.58), functional outcome (p > 0.1) and 5-year postoperative survival rank (p = 0.28) were comparable in both groups. Delayed reconstruction after HNC resection was feasible. Perioperative morbidity, functional outcome and overall survival were comparable to immediate reconstruction.

Prediction of Cervical Lymph Node Metastasis in Clinically Node-Negative T1 and T2 Papillary Thyroid Carcinoma Using Supervised Machine Learning Approach.

Papillary thyroid carcinoma (PTC) is generally considered an indolent cancer. However, patients with cervical lymph node metastasis (LNM) have a higher risk of local recurrence. This study evaluated and compared four machine learning (ML)-based classifiers to predict the presence of cervical LNM in clinically node-negative (cN0) T1 and T2 PTC patients. The algorithm was developed using clinicopathological data from 288 patients who underwent total thyroidectomy and prophylactic central neck dissection, with sentinel lymph node biopsy performed to identify lateral LNM. The final ML classifier was selected based on the highest specificity and the lowest degree of overfitting while maintaining a sensitivity of 95%. Among the models evaluated, the k-Nearest Neighbor (k-NN) classifier was found to be the best fit, with an area under the receiver operating characteristic curve of 0.72, and sensitivity, specificity, positive and negative predictive values, F1 and F2 scores of 98%, 27%, 56%, 93%, 72%, and 85%, respectively. A web application based on a sensitivity-optimized kNN classifier was also created to predict the potential of cervical LNM, allowing users to explore and potentially build upon the model. These findings suggest that ML can improve the prediction of LNM in cN0 T1 and T2 PTC patients, thereby aiding in individual treatment planning.

Single- versus two-stage reconstruction in patients with head and neck cancer: What are the benefits?

In head and neck oncology, surgical treatment frequently results in microvascular reconstruction. Oncologic resection followed by immediate reconstruction is often associated with prolonged working and surgical duration, challenging a surgeon's concentration level and potentially worsening patient outcome. To improve the surgeon's performance and to reduce risk of potential complications, we implemented a two-stage procedure in patients with head and neck cancer. This study critically analyzed the surgical outcomes, organizational benefits, and investigated job satisfaction among affected health care professionals. A retrospective data analysis of patients who had undergone microvascular reconstruction after oncologic head and neck surgery between 2010 and 2021 included 33 patients (n = 33). Twenty patients underwent single-stage reconstruction (group 1, n = 20) and 13 patients underwent two-stage reconstruction (group 2, n = 13) with 12.2 (± 7.4) days between surgeries. The mean surgical duration, and mean start and end time of the reconstructive surgery component differed significantly (p = 0.002). The mean total complication rate (p = 0.58) did not differ significantly, although a trend toward higher demands for blood products was observed in group 1. There was no significant difference in five-year survival (p = 0.28). A questionnaire on subjective work performance was answered by the affected health care professionals (n = 34) and it revealed that 88% preferred long surgeries to be scheduled first and that 97% work most efficiently in the morning. In conclusion, two-stage reconstruction is a suitable option in selected head and neck cancer patients offering the possibility of optimizing preoperative planning and organization. This may result in regular working hours, reduced surgeon fatigue, and improved job satisfaction without compromising patient outcomes or survival.

Hemorrhagic Shock: Blood Marker Sequencing and Pulmonary Gas Exchange.

BACKGROUND: The early identification of internal hemorrhage in critically ill patients may be difficult. Besides circulatory parameters, hemoglobin and lactate concentration, metabolic acidosis and hyperglycemia serve as laboratory markers for bleeding. In this experiment, we examined pulmonary gas exchange in a porcine model of hemorrhagic shock. Moreover, we sought to investigate if a chronological order of appearance regarding hemoglobin, lactatemia, standard base excess/deficit (SBED) and hyperglycemia exists in early severe hemorrhage. METHODS: In this prospective, laboratory study, twelve anesthetized pigs were randomly allocated to exsanguination or a control group. Animals in the exsanguination group (n = 6) endured a 65% blood loss over 20 min. No intravenous fluids were administered. Measurements were taken before, immediately after, and at 60 min after the completed exsanguination. Measurements included pulmonary and systemic hemodynamic variables, hemoglobin concentration, lactate, base excess (SBED), glucose concentration, arterial blood gases, and a multiple inert gas assessment of pulmonary function. RESULTS: At baseline, variables were comparable. Immediately after exsanguination, lactate and blood glucose were increased (p = 0.001). The arterial partial pressure of oxygen was increased at 60 min after exsanguination (p = 0.04) owing to a decrease in intrapulmonary right-to-left shunt and less ventilation-perfusion inequality. SBED was different to the control only at 60 min post bleeding (p < 0.001). Hemoglobin concentration did not change at any time (p = 0.97 and p = 0.14). CONCLUSIONS: In experimental shock, markers of blood loss became positive in chronological order: lactate and blood glucose concentrations were raised immediately after blood loss, while changes in SBED lagged behind and became significant one hour later. Pulmonary gas exchange is improved in shock.

An Individualized, Less-Invasive Surgical Approach Algorithm Improves Outcome in Elderly Patients Undergoing Mitral Valve Surgery.

BACKGROUND: For mitral valve surgery (MVS) in elderly, frail patients with increasing life expectancy, finding the least harmful means of access is a challenge. In the complexity of MVS approach evolution, using three different approaches (mini-thoracotomy (MT), partial upper-sternotomy (PS), full-sternotomy (FS), we developed a personalized, minimized-invasiveness algorithm for MVS. METHODS: In this retrospective analysis, 517 elderly patients (≥70 years) were identified who had undergone MVS ± TV repair. MVS was performed via MT (n = 274), FS (n = 128) and PS (n = 115). The appropriate access type was defined according to several clinical patient conditions. Using uni- and multivariate regression models, we analyzed combined operative success (residual MV regurgitation, conversion to MV replacement or larger thoracic incisions); perioperative success (30-days mortality, thoracotomy, ECMO, pacemaker implantation, dialysis, longer ventilation); and reoperation-free long-term survival. An additional EuroSCORE2 adjustment was performed to reduce the bias of clinical conditions between all access types. RESULTS: The EuroSCORE2-adjusted Cox regression analysis showed significantly increased reoperation-free survival in the MT cohort compared to FS (HR 0.640; 95% CI 0.442-0.926; p = 0.018). Mortality was additionally reduced after the implementation of PS (p = 0.023). Combined operative success was comparable between the three access types. The perioperative success was higher in the MT cohort compared to FS (OR 2.19, 95% CI 1.32-3.63; p = 0.002). CONCLUSION: Less-invasive approaches in elderly patients improve perioperative success and reoperation-free survival in those undergoing MVS procedures.

[Linkage of Clinical and Claims Data in the Evaluation of Post-Stroke Care - SeDaStro: Experiences from the Tyrolian StrokeCard Program]. / Linkage von klinischen Primärdaten und Krankenkassenabrechnungsdaten in der Evaluation der Schlaganfallversorgung ­ SeDaStro: Erfahrungen aus dem Tiroler StrokeCard-Programm.

AIMS AND OBJECTIVES: Data linkage is of paramount importance in the evaluation of treatment regimens for chronic diseases where different health care sectors are involved. A comprehensive picture of long-term treatment effects and, in particular, the cost-effectiveness ratio of treatment approaches can only be drawn when data from various sources are merged and analyzed together. METHODOLOGICAL PROBLEMS AND CHALLENGES: Regarding post-acute stroke care, the present study gives an example of an exact deterministic data linkage procedure including clinical patient records and claims data of TGKK, the main Tyrolean statutory health insurance fund. Typical problems known from other data linkage projects also emerged in the so-called StrokeCard program conducted at the Medical University of Innsbruck. Distinctive Austrian features (the majority of the Austrian population benefits from a mandatory social insurance system without freedom of choice) facilitated the feasibility of the data linkage procedures. RESULTS: Over the recruitment period 01/2014-12/2015, 540 patients could be assigned to the operative dataset. Of these, 367 patients were part of the StrokeCard group (i. e. the treatment group), and 173 belonged to the usual care group (i. e. the control group); 11 patients did not complete the one-year follow-up period (7 treatment group patients vs. 4 control group patients); 7 of them died during the study (5 treatment group patients vs. 2 control group patients). For all 540 patients, TGKK claims data were available for the time-frames of one year before recruitment and one year after discharge from the University hospital. All data could be used in the health-economic evaluation of the StrokeCard program. CONCLUSIONS: The linking of clinical patient records with data collected by SHI funds opens a window of opportunities for analyses of medical care. Counter-intuitively, Austrian health services research activities have limited experience in data linkage approaches, alhough studies based on the linkage of clinical patient records and claims data are indispensable for the evaluation of complex multi-sectoral treatment schemes. The current project proves the feasibility of data linkage mechanisms in the Austrian context. This should be regarded as an impetus for extending data linkage principles to evaluation studies in the future.

Algorithms to identify COPD in health systems with and without access to ICD coding: a systematic review.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) causes significant morbidity and mortality worldwide. Estimation of incidence, prevalence and disease burden through routine insurance data is challenging because of under-diagnosis and under-treatment, particularly for early stage disease in health care systems where outpatient International Classification of Diseases (ICD) diagnoses are not collected. This poses the question of which criteria are commonly applied to identify COPD patients in claims datasets in the absence of ICD diagnoses, and which information can be used as a substitute. The aim of this systematic review is to summarize previously reported methodological approaches for the identification of COPD patients through routine data and to compile potential criteria for the identification of COPD patients if ICD codes are not available. METHODS: A systematic literature review was performed in Medline via PubMed and Google Scholar from January 2000 through October 2018, followed by a manual review of the included studies by at least two independent raters. Study characteristics and all identifying criteria used in the studies were systematically extracted from the publications, categorized, and compiled in evidence tables. RESULTS: In total, the systematic search yielded 151 publications. After title and abstract screening, 38 publications were included into the systematic assessment. In these studies, the most frequently used (22/38) criteria set to identify COPD patients included ICD codes, hospitalization, and ambulatory visits. Only four out of 38 studies used methods other than ICD coding. In a significant proportion of studies, the age range of the target population (33/38) and hospitalization (30/38) were provided. Ambulatory data were included in 24, physician claims in 22, and pharmaceutical data in 18 studies. Only five studies used spirometry, two used surgery and one used oxygen therapy. CONCLUSIONS: A variety of different criteria is used for the identification of COPD from routine data. The most promising criteria set in data environments where ambulatory diagnosis codes are lacking is the consideration of additional illness-related information with special attention to pharmacotherapy data. Further health services research should focus on the application of more systematic internal and/or external validation approaches.