Marcus Thudium

Robotic-assisted surgery has become increasingly prevalent across various surgical disciplines. Understanding anesthesiological factors influencing perioperative outcome is essential for optimizing patient care. This retrospective analysis evaluated 200 patients who underwent robotic surgery across three surgical categories: gastrointestinal (GI, n=60), hepatopancreticobiliary (HPB, n=28), and colorectal (n=112) procedures. We conducted an exploratory analysis of associations between anesthesiological parameters—including fluid management, surgical duration, and blood loss—and clinical outcomes such as intensive care unit (ICU) length of stay, total hospital length of stay, complication severity (Clavien-Dindo classification) using univariable and multivariable regression models. The exploratory analyses suggested potential associations between surgical duration and outcomes across surgical specialties in multivariable analysis. For GI procedures, longer surgical duration was associated with higher odds of severe complications (Clavien-Dindo grade ≥III; OR = 1.80 (1.21, 2.66)). In colorectal surgery, surgical duration was independently associated with both development of severe complications (OR = 1.28 (1.01, 1.62)) and total hospital length of stay (log-scale, β = 0.08 (0.03, 0.12)). Fluid intake was associated with an increased hospital length of stay in colorectal surgery (log-scale, β = 0.10 (0.03, 0.17)). Anesthesiological management, particularly surgical duration and fluid management, showed associations with perioperative outcomes in robotic surgery. The estimated effects provide preliminary insights into the magnitude of these associations and may serve as a basis for hypothesis generation and the design of future prospective studies. Further studies are needed to confirm these findings and to investigate the potential clinical relevance of anesthesiological and perioperative management strategies.

Background/Objectives: Chronic subdural hematoma (cSDH) is one of the most common neurosurgical disorders in older adults and remains associated with a relevant recurrence rate despite standardized surgical treatment. Identifying postoperative factors that predict recurrence may improve postoperative surveillance and surgical strategy. We therefore investigated whether the density of the residual hematoma on early postoperative computed tomography (CT) is associated with recurrence after burr-hole trepanation. Methods: We retrospectively analyzed all consecutive patients who underwent burr-hole trepanation for cSDH at our institution between 2016 and 2021. Residual hematoma density was measured in Hounsfield units (HU) on postoperative CT scans. Recurrence was defined as symptomatic hematoma reaccumulation requiring reoperation. Results: A total of 223 patients met the inclusion criteria. The overall recurrence rate was 20.2%. Mean residual hematoma density was significantly higher in the recurrence group than in the non-recurrence group (23.2 ± 13.1 HU vs. 19.0 ± 9.1 HU; p = 0.005). ROC analysis identified an optimal cutoff value of 19 HU (AUC 0.578, 95% CI 0.511–0.645; p = 0.022) with sensitivity of 57.8%, and a specificity of 57.9%. Patients with residual hematoma density ≥19 HU had a significantly higher recurrence rate than those with lower density (25.7% vs. 15.6%; p = 0.043). In multivariable logistic regression, higher residual density remained an independent predictor of cSDH recurrence (p = 0.008, OR 1.9; 95% CI 1.2–3.0). Conclusions: Higher postoperative residual hematoma density is an independent predictor of recurrence after burr-hole trepanation for cSDH. Residual density on early postoperative CT may serve as a simple and clinically accessible imaging marker of incomplete hematoma clearance and may help refine postoperative risk assessment. Nevertheless, the low AUC limits interpretation of predictive performance.

Objective: Cerebral cavernous malformations (CCMs) are usually occult but can present with a symptomatic hemorrhage. Treatment recommendations for CCMs are still controversially discussed, as all CCMs have signs of chronic hemorrhage. The distinction of acute hemorrhage can be difficult, especially when patients only present with mild symptoms. Because of emerging evidence supporting inflammatory burden as a main avenue in the disease pathogenesis of CCMs, the aim of the present study was to investigate routine inflammatory parameters to support decision-making in ambiguous cases. Methods: A total of 87 patients who underwent CCM resection at the authors’ institution between 2008 and 2021 were included in this study. Data were recorded retrospectively. Patients were dichotomized into two groups: those with acute hemorrhage and those without, as a control group (e.g., resection for seizure control). Inflammatory parameters included C-reactive Protein (CrP), White Blood Cell Count (WBC), Red Cell Distribution Width (RDW), and Mean Platelet Volume/Platelet Count Ratio (MPV/PC). Results: The receiver operating characteristic curve demonstrated moderate diagnostic accuracy for predicting acute hemorrhage from CCM based on WBC at admission (AUC: 0.74, 95%-CI: 0.63–0.84) with a cut-off of ≥6.595 G/L. The multivariable analysis confirmed that having a WBC > 6.595 G/L is an independent predictor for acute hemorrhage of CCM (adjusted odds ratio: 4.5, 95%-CI: 1.8–11.2, p < 0.001). Conclusions: A white blood cell count >6.595 G/L was significantly associated with acute hemorrhage in CCMs and appears to be a quick-to-use biomarker in controversial cases. Moreover, leukocytosis emphasizes the involvement of neuroinflammation in acute hemorrhage of CCM. Further investigations are needed to analyze the precise role of inflammation in CCM pathogenesis and its impact on treatment strategies.

BACKGROUND: Postoperative delirium (POD) is a frequent and serious complication after surgery. Parameters of the electroencephalogram (EEG), such as the Bispectral Index and the occurrence of burst suppression, have been associated with POD. We analyzed the predictive properties of periodic and aperiodic parameters of the EEG power spectrum. METHODS: In a secondary post-hoc analysis of a prospective observational study, patients with an age of at least 60 years undergoing major cardiac or non-cardiac surgery were analyzed. The frontal intraoperative raw EEG was recorded by a BIS monitor and offline analyzed with the FOOOF toolbox, revealing the periodic and aperiodic parameters of the power spectrum. Patients were screened for POD and divided in a 2:1 ratio into a training and a validation cohort. Predictors of POD were identified by uni- and multivariable logistic regression. RESULTS: Thirty-two out of the 120 training group patients developed POD. These showed a significantly longer median duration of surgery (286 [interquartile range {IQR} 236–391] vs 223 [127–331] min, P = .005), lower median BIS (40.4 [IQR 38.1–43.4] vs 42.7 [39.5–46.0], P = .038), and a higher mean aperiodic exponent (2.09 ± 0.19 vs 1.99 ± 0.17, P = .017). Duration of surgery (odds ratio [OR] = 1.01; 95% confidence interval [CI], 1.00–1.01, P = .005), peak center frequency (OR = 0.79; CI, 0.62–0.97, P = .039) and aperiodic exponent (OR = 23.2; CI, 2.1–318.2, P = .013) were predictors of POD according to univariable logistic regression. At a cutoff of 1.967, the aperiodic exponent had a sensitivity of 0.813 and a specificity of 0.478 for the prediction of POD. A low duration of time spent in burst suppression was observed in both patients with POD (67 [6–363] s) and without POD (173 [4–641] s, P = .30), and cumulative burst suppression time was not a predictor of POD. In a stepwise regression model, age, duration of surgery, peak power, and the aperiodic exponent were associated with POD (AUROC = 0.80 (CI, 0.71–0.89, P < .001). The predictive model was confirmed in the validation group (n = 60) with an AUROC = 0.77 (CI, 0.65–0.90, P = .001). CONCLUSIONS: A higher aperiodic exponent, for example, a less complex EEG signal, is associated with a greater POD risk, especially in combination with known POD predictors such as age and duration of surgery.

Introduction: Near-infrared spectroscopy is now a popular method in neuromonitoring. Derived parameters like cerebral oxygenation index or Fast Fourier Transform based coherence estimates between blood pressure and cerebral blood flow have their limitations of use for stationary data and low time resolution. Wavelet transfer function analysis can be employed to estimate coherence, gain and phase relationship between two signals without these restrictions.Methods: We aimed to extend the previously described Grinsted wavelet package with rectified bias of power and transfer function gain estimation of cerebral autoregulation assessment. The algorithm was validated in simulated signals and data of five healthy male subjects undergoing a protocol to produce large changes in hemodynamics by using lower body positive pressure (LBNP) with mild hypoxia and lower body negative pressure (LBNP). We intended to compare wavelet-based observations with FFT-based estimates.Results: We found good agreement between wavelet and FFT-based coherence and gain of cerebral tissue oxygenation index, in Bland Altman Plot and linear correlations for repeated measurement especially in the low frequency range (0.04 -0.15 Hz, coherence: r = 0.69, p < 0.001, gain: r = 0.74, p = 0.001), but was less in the very low frequency range (≤0.04 Hz, coherence: r = 0.65, p < 0.001, gain: r = 0.66, p < 0.001) and high frequency range (0.15-0.4 Hz, coherence: r = 0.39, p < 0.001, gain: r = 0.71, p = 0.001). FFT-based coherence was smaller than wavelet estimates for values <0.5.Discussion: We demonstrated good agreement in power, coherence, transfer function gain estimates between FFT-based method and our modified wavelet method. This was confirmed in simulated data and in healthy subjects undergoing LBNP and LBPP with hypoxia. Near-infrared spectroscopy-derived wavelet transform could be useful for exploring cerebral autoregulation dynamics, especially in non-stationary data.

Background: Despite the success of transcatheter aortic valve repair (TAVR) over the past years, its impact on global and cerebral hemodynamics remains largely unexplored. Changes in cerebral blood flow may be associated with delirium, which may occur in 26 to 29% of cases. We aimed to examine the relationships between global hemodynamic parameters and cerebral parameters in patients who underwent TAVR and their impact on postinterventional delirium. Methods: Patients scheduled for TAVR were enrolled after obtaining written informed consent. Patients received light sedation according to standard procedures. Cerebral blood flow (CBF) was measured with a noninvasive near-infrared spectroscopy-based method using intravenous indocyanine green injection. CBF measurements were taken at the beginning of the TAVR procedure and after the valve was in place. Patients were screened for delirium using CAM-ICU and NuDESC tests before and after intervention. Results: A total of 52 of 60 patients remained for analysis. Thirteen patients (25%) developed delirium. Mean arterial pressure (MAP) remained unchanged, while cardiac output increased after TAVR by 44%. CBF also increased after TAVR. No significant difference was observed in CBF changes between the groups with and without delirium. A linear mixed model analysis revealed a linear relationship between CO and CBF but not between MAP and CBF. In an exploratory analysis, decreased cerebral oxygenation and increased deoxygenated hemoglobin, as measured by NIRS after TAVR, were associated with delirium. Conclusions: The results confirm that CO is an independent factor in CBF, while CBF changes per se are not linked to delirium. However, we found a mismatch between CBF and regional cerebral parameters, which may reflect cerebral metabolism and its relation to the development of delirium. This remains to be confirmed by further studies.

Background and Objectives: Remifentanil is a member of the fentanyl family and a short-acting, esterase-metabolized opioid that offers potential advantages over fentanyl in ophthalmic surgeries characterized by rapid patient turnover. This study aimed to compare two different analgesia induction regimes, remifentanil or fentanyl, with respect to intraoperative hypotensive events and perioperative process times in patients undergoing ophthalmic surgery under general anesthesia. Materials and Methods: Clinical data of 500 patients either receiving remifentanil infusion (R group, 0.4–0.5 μg/kg/min at induction, and then 0.1 µg/kg/min maintenance dose) or fentanyl bolus (F group, 1 μg/kg for induction followed by 0.1 μg/kg/min remifentanil maintenance dose) were analyzed in this retrospective study. All patients received a propofol injection as part of the induction and sevoflurane for the maintenance of anesthesia. We investigated hemodynamic events as defined by the administration of vasopressors, atropine and Akrinor (Theodrenaline and Cafedrine), as well as procedural times in the two groups. Results: There was no difference in hypotensive events between the two groups. However, there was a relationship between preoperative ASA (American Society of Anesthesiologists) status and vasopressor administration. The amount of propofol for the induction of anesthesia exhibited a significant correlation to the age of the patients (p < 0.05). The time from the end of anesthesia to discharge from the recovery room was significantly reduced by approximately 6 min per patient in the remifentanil group (p < 0.01). In conclusion, the induction of anesthesia with high-dose remifentanil combined with propofol can significantly shorten the time span to discharge from the recovery ward compared to fentanyl bolus administration, without an increase in the administration of vasopressors in patients undergoing ophthalmic surgery in general anesthesia. Conclusions: These findings suggest that remifentanil may be a more effective choice for anesthesia management in settings with high patient turnover.

Background: Decreased cerebral oximetry (rSO₂) in cardiac surgery is associated with postoperative delirium (POD). However, interventions optimizing intraoperative rSO₂ are inconclusive. Methods: In this prospective observational cohort study, the relationship between rSO₂, middle cerebral artery blood flow velocity (MCAV), and processed EEG was assessed in cardiac surgery patients with and without POD. MCAV was continuously recorded by transcranial Doppler sonography (TCD), together with continuous rSO₂ and bispectral index (BIS) monitoring. Cardiopulmonary bypass (CPB) flow rate was adjusted according to body surface area. The cohort was divided into the POD and control groups, according to the postoperative results of the confusion assessment method (CAM/CAM-ICU), the 4A’s test (4AT), and the Delirium Observation Scale (DOS). A mixed model analysis was performed for intraoperative raw data. The cerebral autoregulation index was calculated from TCD, rSO₂, and arterial pressure values. Differences in impaired autoregulation were compared using the Mann–Whitney U test. Results: A total of 41 patients were included in this study. A total of 13 patients (36.11%) developed postoperative delirium. There were no significant differences in the baseline characteristics of patients with or without POD. Patients with POD had lower BIS values during CPB (adjusted mean difference −4.449 (95% CI [−7.978, −0.925])). RSO₂ was not significantly reduced in POD, (adjusted mean difference: −5.320, 95% CI [−11.508, 0.874]). In contrast, MCAV was significantly increased in POD (10.655, 95% CI [0.491, 20.819]). The duration of cerebral autoregulation impairment did not differ significantly for TCD and cerebral oximetry-derived indices (p = 0.4528, p = 0.2715, respectively). Conclusions: Our results suggest that disturbed cerebral metabolism reflects a vulnerable brain which may be more susceptible to overperfusion during CPB, which can be seen in increased MCAV values. These phenomena occur irrespectively of cerebral autoregulation.

Introduction: Cerebrovascular complications are feared but also commonly reported in patients with COVID-19 requiring extracorporeal membrane oxygenation (ECMO) support therapy. Besides other reasons, a connection between impaired cerebral autoregulation and SARS-CoV-2 infection as a mechanism for an increase in cerebrovascular complications has been hypothesized.Methods: In an observational single-center study, we investigated a cohort of 48 patients requiring veno-venous ECMO support therapy with (n = 31) and without SARS-CoV-2 infection (n = 17). Cerebral autoregulation was assessed with the cerebral oximetry-derived autoregulation index (ORx) based on a moving correlation between arterial pressure and cerebral oximetry.Results: Patients with ECMO support therapy and SARS-CoV-2 experienced more time with impaired cerebral autoregulation than without SARS-CoV-2 [17 ± 9 vs. 13 ± 9% (p = 0.027)]. Patients with SARS-CoV-2 suffering from cerebrovascular complications had more time with impaired autoregulation than non SARS-CoV-2 patients with these complications (19 ± 9 vs. 10 ± 4%, p = 0.032).Conclusion: Our results suggest a connection between SARS-CoV-2 and impaired cerebral autoregulation as well as cerebrovascular complications in SARS-CoV-2 patients.