Background: Surgical aortic valve replacement (SAVR) is an established therapy for severe calcific aortic stenosis. Enhanced recovery after cardiac surgery (ERACS) protocols have been shown to improve outcomes for elective cardiac procedures. The COVID-19 pandemic prompted early extubation post-elective surgeries to preserve critical care resources. Aim of this study: To investigate the effects of extubating patients within 6 h post-elective SAVR on hospital and ICU length of stay, mortality rates, ICU readmissions, and postoperative pneumonia. Study Design and methods: The retrospective analysis at the University Hospital Aachen, Germany, includes data from 2017 to 2022 and compares a total of 73 elective SAVR patients. Among these, 23 patients were extubated within 6 h (EXT group), while 50 patients remained intubated for over 6 h (INT group). Results: The INT group experienced longer postoperative ventilation, needed more vasopressor support, had a higher incidence of postoperative pneumonia, and longer ICU length of stay. No significant differences were noted in overall hospital length of stay, mortality, or ICU readmission rates between the groups. Conclusion: This study demonstrates that early extubation in high-risk, multimorbid surgical aortic valve replacement patients is safe, and is associated with a reduction of pneumonia rates, and with shorter ICU and hospital length of stays, reinforcing the benefits of ERACS protocols, especially critical during the COVID-19 pandemic to optimize intensive care use.

Purpose: Coronary artery bypass graft (CABG) surgery is the standard treatment for advanced coronary artery disease. Despite evidence supporting enhanced recovery after surgery (ERAS) programs, many hospitals continue to keep patients intubated following on-pump CABG surgery. The coronavirus disease 2019 (COVID-19) pandemic further strained intensive care unit (ICU) capacities, leading to the consideration of immediate extubation after elective surgeries like CABG surgeries. The aim of this study was to assess whether extubation in the operating room after elective on-pump CABG surgery would reduce the ICU length of stay, the ICU readmission, and the ICU mortality in a population of patients undergoing on-pump CABG surgery as opposed to the conventional approach with patients remaining intubated. Methods: This study is a retrospective single-center study, including data from the University Hospital Aachen, Germany. Clinical data from 2019 to 2022 were analyzed, focusing on patients who underwent on-pump CABG surgery. Primary endpoints studied were the duration of ICU stay, rates of ICU readmission, and ICU mortality. Secondary outcomes included the hospital length of stay, hospital mortality, and the occurrence of postoperative pneumonia. Results: Ninety-seven patients who underwent elective on-pump CABG surgery were identified. There were no variations in outcomes, including ICU and hospital stays, mortality, ICU readmission, or postoperative pneumonia between the two groups. Conclusion: Extubation in the operating room after on-pump CABG surgery did not result in significant differences in outcomes compared to patients who remained intubated. Graphical

Background: Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a critical intervention for patients with severe lung failure, especially acute respiratory distress syndrome (ARDS). The weaning process from ECMO relies largely on expert opinion due to a lack of evidence-based guidelines. The ventilatory ratio (VR), which correlates with dead space and mortality in ARDS, is calculated as [minute ventilation (mL/min) x arterial pCO₂ (mmHg)]/[predicted body weight × 100 × 37.5]. Objectives: The aim of this study was to determine whether the VR alone can serve as a reliable predictor of safe or unsafe liberation from VV-ECMO in critically ill patients. Methods: A multicenter retrospective analysis was conducted, involving ARDS patients undergoing VV-ECMO weaning at Massachusetts General Hospital (January 2016 – December 2020) and at the University Hospital Aachen (January 2012–December 2021). Safe liberation was defined as no need for ECMO recannulation within 48 h after decannulation. Clinical parameters were obtained for both centers at the same time point: 30 min after the start of the SGOT (sweep gas off trial). Results: Of the patients studied, 83.3% (70/84) were successfully weaned from VV-ECMO. The VR emerged as a significant predictor of unsafe liberation (OR per unit increase: 0.38; CI: 0.17–0.81; p = 0.01). Patients who could not be safely liberated had longer ICU and hospital stays, with a trend towards higher mortality (38% vs. 13%; p = 0.05). Conclusions: The VR may be a valuable predictor for safe liberation from VV-ECMO in ARDS patients, with higher VR values associated with an elevated risk of unsuccessful weaning and adverse clinical outcomes.

The occurrence of thrombus formation within an extracorporeal membrane oxygenator is a common complication during extracorporeal membrane oxygenation therapy and can rapidly result in a life-threatening situation due to arterial thromboembolism, causing stroke, pulmonary embolism, and limb ischemia in the patient. The standard clinical practice is to monitor the pressure at the inlet and outlet of oxygenators, indicating fulminant, obstructive clot formation indicated by an increasing pressure difference (ΔP). However, smaller blood clots at early stages are not detectable. Therefore, there is an unmet need for sensors that can detect blood clots at an early stage to minimize the associated thromboembolic risks for patients. This study aimed to evaluate if forward scattered light (FSL) measurements can be used for early blood clot detection and if it is superior to the current clinical gold standard (pressure measurements). A miniaturized in vitro test circuit, including a custom-made test chamber, was used. Heparinized human whole blood was circulated through the test circuit until clot formation occurred. Four LEDs and four photodiodes were placed along the sidewall of the test chamber in different positions for FSL measurements. The pressure monitor was connected to the inlet and the outlet to detect changes in ΔP across the test chamber. Despite several modifications in the LED positions on the test chamber, the FSL measurements could not reliably detect a blood clot within the in vitro test circuit, although the pressure measurements used as the current clinical gold standard detected fulminant clot formation in 11 independent experiments.

Background: In Germany, over 16 million pre-anesthesia consultations (PAC) are conducted annually, which is associated with a significant investment of time and high costs. However, some PACs do not lead to surgery, which is inefficient and results in wasted resources. This study evaluates the costs and time loss associated with PACs that did not result in anesthesia-required surgery or diagnostic procedures and identifies the predictors of these cancellations. Methods: A total of 1357 PACs conducted in September 2023 at the University Hospital Aachen were retrospectively analyzed. The study groups included patients whose PACs resulted in anesthesia-required surgery or diagnostic procedures (SURG group) and those whose PACs did not (NoSURG group). The primary outcomes were costs in EUR and the hours lost due to PACs not resulting in anesthesia for patients in the NoSURG group, and the secondary outcomes included the predictors of surgery cancellations, the frequency of missing test results, necessary pre-anesthesia re-consultations due to missing tests, and hospital length of stay for NoSURG patients. Results: In September 2023, 7.3% (99/1357) of PACs did not result in anesthesia-required procedures. ASA scores were higher in the NoSURG group, with almost two-thirds classified as ASA III or higher (p = 0.001). The NoSURG group had more planned postoperative IMC stays (16.2% vs. 9.3%; p = 0.027) and fewer medical report letters available (50.5% vs. 97.1%; p < 0.001). The reasons for surgery cancellation were often undetermined (47.5%). Other reasons included surgeons opting for a conservative approach (19.2%), patient decisions (9.1%), surgery no longer indicated (8.1%), hospital capacity constraints (5.1%), patient transfers (3.0%), and high surgical risk (8.1%). The annual projected cost for the NoSURG group was EUR 29,182, with 888 h of time loss. The median hospital length of stay for the NoSURG group was 5 (2; 15) days. Conclusions: PACs that were carried out but were not followed by anesthesiology services led to substantial costs and time loss. Improving medical report availability and assessing procedure necessity beforehand might help to reduce these expenses and time losses.

Background: The venous-to-arterial difference in partial pressure of carbon dioxide (CO2 gap) has been suggested as a marker of cardiac output and clinical outcomes. This study aimed to evaluate the CO2 gap as a prognostic indicator for 28-day survival in patients undergoing transcatheter aortic valve replacement (TAVR) and to explore its relationship with cardiac function and lactate levels. Methods: In this prospective cohort study, 50 TAVR patients were stratified based on their left ventricular ejection fraction (LV-EF) and survival status. Central venous and arterial blood samples were collected at five time points to measure blood gas parameters. The primary endpoint was the prognostic value of the CO2 gap for 28-day survival. Secondary endpoints included group differences in the CO2 gap, its correlation with lactate levels, and CO2 content analysis. Results: ROC analysis indicated limited prognostic value for 28-day survival. The CO2 gap was higher in non-survivors than in survivors (11.1 mmHg vs. 6.8 mmHg, p = 0.039), but showed no significant difference between individual time points. The CO2 gap between cardiac (LV-EF ≤ 50%) and non-cardiac (LV-EF > 50%) groups showed no significant difference. Lactate and CO2 gap showed no correlation, except at T2 in the cardiac group (p = 0.039, r = 0.525). CO2 content showed no significance, except at T5, where it was significantly higher in survivors (5.3 mL/dL vs. 1.1 mL/dL, p = 0.003). Conclusions: The CO2 gap did not emerge as a reliable prognostic marker for 28-day survival in TAVR patients. Further studies are needed to explore its clinical relevance.