Ana Kowark’s research while affiliated with University of Bonn and other places

What is this page?


This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.

Publications (100)


Fig. 2 Morphological analysis of intracranial pressure (ICP). a Schematic representation of the relationship between intracranial volume, ICP, and changes in ICP pulse amplitude and shape. b Interpretation of the ICP pulse shape index (PSI)
Impact of age and mean intracranial pressure on the morphology of intracranial pressure waveform and its association with mortality in traumatic brain injury
  • Article
  • Full-text available

February 2025

·

132 Reads

Critical Care

·

·

·

[...]

·

Frederick A. Zeiler

Background Morphological analysis of intracranial pressure (ICP) pulse waveforms provides indirect information on cerebrospinal compliance, which might be reduced by space-occupying lesions but also by intracranial hypertension and aging. This study investigates the impact of age and mean ICP on the shape and amplitude of ICP pulse waveform in traumatic brain injury (TBI). Additionally, it explores the association between morphological parameters and mortality after TBI. Methods ICP recordings from 183 TBI patients (median age: 50 (30, 61) years) from the CENTER-TBI database were retrospectively analyzed. ICP morphology was assessed using the artificial intelligence-based pulse shape index (PSI) and peak-to-peak amplitude of ICP pulse waveform (AmpICP). The impact of mean ICP, age, and their interaction on PSI and AmpICP were estimated using factorial ANOVA. To account for influence of disturbance in the intracranial volume on AmpICP and PSI, a multiple regression analysis was performed using age, mean ICP, and the Rotterdam CT score as explanatory variables. The associations of AmpICP and PSI with six-month mortality were assessed using the area under the ROC curve (AUC). Results Age had a predominant influence on PSI ( p < 0.01), accounting for 33.1% of its variance, while mean ICP explained 6.6% ( p < 0.01). Conversely, mean ICP primarily affected AmpICP ( p < 0.01), explaining 22.8% of its variance, with age contributing 8.0% ( p < 0.01). A combined effect of age and mean ICP on AmpICP ( p = 0.01) explained 11.7% of its variance but did not influence PSI. After accounting for Rotterdam CT score, the results remained consistent, indicating that advanced age has the strongest impact on PSI (β = 0.342, p < 0.01) while elevated mean ICP has dominant influence on AmpICP (β = 0.522, p < 0.01). Both AmpICP and PSI were moderately associated with mortality (AUC: 0.76 and 0.71, respectively). Conclusions AmpICP and PSI capture distinct aspects of cerebrospinal compliance. PSI appears to reflect age-related stiffening of the cerebrovascular system, while AmpICP, influenced by mean ICP, indicates acute volume compensatory changes. Combined, they provide a more comprehensive assessment of cerebrospinal volume–pressure compensation. Both morphological metrics are associated with mortality after TBI. As cerebrospinal compliance declines with age, older TBI patients become more susceptible to uncontrolled rises in ICP, which can worsen their outcome.

Download

Effect of parecoxib on postoperative delirium in patients with hyperlipidemia: a randomized, double-blind, single-center, superiority trial

February 2025

·

5 Reads

International Journal of Surgery

Background Hyperlipidemia has been implicated in the higher risk of developing postoperative delirium. Prostaglandin endoperoxide synthase-2 mediates neuroinflammatory processes in postoperative delirium. This study aims to investigate whether preoperative administration of parecoxib is more efficient than a placebo in averting postoperative delirium in patients with hyperlipidemia. Materials and methods In this randomized, double-blind, superiority trial, participants with hyperlipidemia were randomized in a 1:1 ratio to receive parecoxib (40 mg parecoxib administered intravenously before anesthesia induction) or placebo (normal saline). The primary outcome was postoperative delirium incidence within three days, with a 5.4% difference set as the superiority threshold. Secondary outcomes were cumulative incidences of emergence delirium and prostaglandin endoperoxide synthase-2 levels, inflammatory cell counts, and pain score on postoperative day 1 and postoperative adverse events. Results This trial conducted between August 2023 and August 2024 at a tertiary hospital in China included 452 adults with hyperlipidemia, with 226 in the parecoxib group and 226 in the placebo group. The incidence of postoperative delirium in the parecoxib group was 13.72%, a reduction of 12.39% compared to the placebo group (hazard ratio, 0.491; 95% confidence interval: 0.318 to 0.759; P < 0.001). The parecoxib group also had a lower incidence of emergence delirium, prostaglandin endoperoxide synthase-2 levels, white blood cell counts and neutrophil, and pain scores on postoperative day 1. The occurrence of adverse events was comparable between the two groups. Prostaglandin endoperoxide synthase-2 expression levels, white blood cell counts, and pain scores mediated the reduction of postoperative delirium incidence by parecoxib. Conclusion Parecoxib may help in reducing the hyperlipidemia-related postoperative delirium incidence. The effective anti-inflammatory activity of prostaglandin endoperoxide synthase-2 inhibition by parecoxib and postoperative pain control may be important mechanisms for preventing postoperative delirium.



Fig. 3 The pipeline of the analysis uses windowed time-lagged crosscorrelation (WTLCC) (Upper panel) WTLCC is applied to two series I 1 (n) and I 2 (n) of length N, creating a matrix with K rows and J columns. (Lower panel) A custom convolutional neural network (CNN)
Fig. 4 A receiver operating characteristic (ROC) curve and confusion matrix for the convolutional neural network (CNN) model utilizing windowed time-lagged cross-correlation (WTLCC) in two experiments. The first experiment ('WTLCC utility') aimed to predict short-term outcome and was trained and validated on the Wroclaw University Hospital (WUH) database (P training = 31 with 1,079
Exploration of simultaneous transients between cerebral hemodynamics and the autonomic nervous system using windowed time-lagged cross-correlation matrices: a CENTER-TBI study

December 2024

·

131 Reads

Acta Neurochirurgica

Background Traumatic brain injury (TBI) can significantly disrupt autonomic nervous system (ANS) regulation, increasing the risk for secondary complications, hemodynamic instability, and adverse outcome. This retrospective study evaluated windowed time-lagged cross-correlation (WTLCC) matrices for describing cerebral hemodynamics–ANS interactions to predict outcome, enabling identifying high-risk patients who may benefit from enhanced monitoring to prevent complications. Methods The first experiment aimed to predict short-term outcome using WTLCC-based convolution neural network models on the Wroclaw University Hospital (WUH) database (P training = 31 with 1,079 matrices, P val = 16 with 573 matrices). The second experiment predicted long-term outcome, training on the CENTER-TBI database (P training = 100 with 17,062 matrices) and validating on WUH (P val = 47 with 6,220 matrices). Cerebral hemodynamics was characterized using intracranial pressure (ICP), cerebral perfusion pressure (CPP), pressure reactivity index (PRx), while ANS metrics included low-to-high-frequency heart rate variability (LF/HF) and baroreflex sensitivity (BRS) over 72 h. Short-term outcome at WUH was assessed using the Glasgow Outcome Scale (GOS) at discharge. Long-term outcome was evaluated at 3 months at WUH and 6 months at CENTER-TBI using GOS and GOS-Extended, respectively. The XGBoost model was used to compare performance of WTLCC-based model and averaged neuromonitoring parameters, adjusted for age, Glasgow Coma Scale, major extracranial injury, and pupil reactivity in outcome prediction. Results For short-term outcome prediction, the best-performing WTLCC-based model used ICP-LF/HF matrices. It had an area under the curve (AUC) of 0.80, vs. 0.71 for averages of ANS and cerebral hemodynamics metrics, adjusted for clinical metadata. For long-term outcome prediction, the best-score WTLCC-based model used ICP-LF/HF matrices. It had an AUC of 0.63, vs. 0.66 for adjusted neuromonitoring parameters. Conclusions Among all neuromonitoring parameters, ICP and LF/HF signals were the most effective in generating the WTLCC matrices. WTLCC-based model outperformed adjusted neuromonitoring parameters in short-term but had moderate utility in long-term outcome prediction.


Genetic vulnerability and adverse mental health outcomes following mild traumatic brain injury: a meta-analysis of CENTER-TBI and TRACK-TBI cohorts

December 2024

·

143 Reads

EClinicalMedicine

Background Post-traumatic stress disorder (PTSD) and depression are common after mild traumatic brain injury (mTBI), but their biological drivers are uncertain. We therefore explored whether polygenic risk scores (PRS) derived for PTSD and major depressive disorder (MDD) are associated with the development of cognate TBI-related phenotypes. Methods Meta-analyses were conducted using data from two multicenter, prospective observational cohort studies of patients with mTBI: the CENTER-TBI study (ClinicalTrials.gov ID NCT02210221) in Europe (December 2014–December 2017) and the TRACK-TBI study in the US (March 2014–July 2018). In both cohorts, the most common causes of injury were road traffic accidents and falls. Primary outcomes, specifically probable PTSD and depression, were defined at 6 months post-injury using scores ≥33 on the PTSD Checklist-5 and ≥15 on the Patient Health Questionnaire-9, respectively. We calculated PTSD-PRS and MDD-PRS for patients aged ≥17 years who had a Glasgow Coma Scale score of 13–15 upon hospital arrival and assessed their association with PTSD and depression following TBI. We also evaluated the transferability of the findings in a cohort of African Americans. Findings Overall, 11.8% (219/1869) and 6.7% (124/1869) patients were classified as having probable PTSD and depression, respectively. The PTSD-PRS was significantly associated with higher adjusted odds of PTSD in both cohorts, with a pooled odds ratio (OR) of 1.55 [95% confidence interval (CI) 1.30–1.84, p < 0.001, I² = 20.8%]. Although the MDD-PRS increased the risk of depression after TBI, it did not reach significance in the individual cohorts. However, in a combined analysis, the risk was significantly elevated with a pooled OR of 1.26 [95% CI 1.03–1.53, p = 0.02, I² = 0%]. The addition of PRSs improved the proportion of outcome variance explained in the two study cohorts from 19.5% and 30.3% to 21.6% and 34.0% for PTSD; and from 11.0% and 22.5% to 12.8% and 22.6% for depression. Patients in the highest cognate PRS quintile had increased odds of 3.16 [95% CI 1.80–5.55] and 2.03 [95% CI 1.04–3.94] of developing PTSD or depression compared to the lowest quintile, respectively. Interpretation Associations of PRSs with PTSD and depression following TBI are not disorder-specific. However, the overlap between MDD-PRS and depression following TBI is less robust compared to PTSD-PRS and PTSD. PRSs could improve risk prediction, and permit enrichment for interventional trials. Funding This study was supported by funding by an FP7 grant from the 10.13039/501100000780European Union, 10.13039/501100007731Hannelore Kohl Stiftung, 10.13039/100009006Integra LifeSciences Corporation, NeuroTrauma Sciences, US 10.13039/100000002National Institutes of Health, US 10.13039/100000005Department of Defense, National Football League Advisory Board, US 10.13039/100000015Department of Energy, and 10.13039/100018727One Mind.




Predicting recovery in patients with mild traumatic brain injury and a normal CT using serum biomarkers and diffusion tensor imaging (CENTER-TBI): an observational cohort study

August 2024

·

223 Reads

·

1 Citation

EClinicalMedicine

·

Stefan Winzeck

·

Marta M. Correia

·

[...]

·

Tommaso Zoerle

Background Even patients with normal computed tomography (CT) head imaging may experience persistent symptoms for months to years after mild traumatic brain injury (mTBI). There is currently no good way to predict recovery and triage patients who may benefit from early follow-up and targeted intervention. We aimed to assess if existing prognostic models can be improved by serum biomarkers or diffusion tensor imaging metrics (DTI) from MRI, and if serum biomarkers can identify patients for DTI. Methods We included 1025 patients aged >18 years with a Glasgow Coma Score >12 and normal CT from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study which recruited between December 19,2014 and December 17, 2017 (NCT02210221). Biomarkers (GFAP, NFL, S100B) were obtained at a median of 8.8 h (Q1–Q3 4.2–16.7) and DTI at 13 days (3–19) after injury. DTI metrics were available in 153 patients for 48 white matter tracts (ICBM-DTI-81 atlas). Incomplete recovery at three months was defined as an extended Glasgow Outcome Scale score <8. Existing prognostic models were fitted with and without biomarkers, or with and without DTI, and internally validated using bootstrapping. Findings 385 (38%) patients had incomplete recovery. Adding biomarkers did not improve performance beyond the best existing clinical prognostic model [optimism-corrected AUC 0.69 (95% CI 0.65–0.72) and R² 17% (11–22)]. Adding DTI metrics significantly enhanced all models [best optimism-corrected AUC 0.82 (0.79–0.85) and R² 75% (39–100)]. The top three prognostic tracts were the left posterior thalamic radiation, left superior cerebellar peduncle and right uncinate fasciculus. Serum biomarkers could have avoided 1 in 5 DTI scans, with GFAP <12 h and NFL 12–24 h from injury performing best. Interpretation DTI substantially improved existing prognostic models for functional outcome in patients with mTBI and a normal CT, and biomarkers could help select patients for MRI. If validated, DTI could allow for targeted follow-up and enrichment of clinical trials of early interventions to improve outcome. Funding EU Seventh Framework Programme, 10.13039/501100007731Hannelore Kohl Stiftung, 10.13039/100018727One Mind, 10.13039/100009006Integra LifeSciences, NeuroTrauma Sciences.




Citations (72)


... The database search identified 98 potentially eligible records. After screening the titles and abstracts, 20 full-text articles were reviewed, of which 9 met the inclusion criteria (Feinkohl et al., 2023;Lin et al., 2022;Zhao et al., 2024;Böhner et al., 2003;Chu et al., 2021;Ding et al., 2024;Li et al., 2021;Sugimoto et al., 2015;Wang et al., 2015) (Figure 1). ...

Reference:

Association between hyperlipidemia and postoperative delirium risk: a systematic review and meta-analysis
Postoperative delirium risk in patients with hyperlipidemia: A prospective cohort study
  • Citing Article
  • August 2024

Journal of Clinical Anesthesia

... Recent research highlights the involvement of the thalamus and the cortex in this process. 67 The thalamus is responsible for processing and transmitting sensory information (except smell) to the cortex, where it is integrated into higher cognitive functions such as perception, decisionmaking and motor control. 68 Both brain regions play critical roles in regulating consciousness, behavior. ...

Repeat traumatic brain injury exacerbates acute thalamic hyperconnectivity in humans
  • Citing Article
  • June 2024

Brain Communications

... Our study shows that such measures can be implemented rapidly, which is crucial given the urgency of the climate crisis. Another German study showed that a 72% reduction of desflurane use was achievable with educational interventions alone (stickers, posters, presentation) [36]. Compared to our study, a higher reduction in desflurane use > 99% may be due to unmounted desflurane vaporisers. ...

Easy-to-implement educational interventions to bring climate-smart actions to daily anesthesiologic practice: a cross-sectional before and after study
  • Citing Article
  • March 2024

Minerva Anestesiologica

... Midazolam premedication significantly enhances patient experience [23] by reducing memory of induction events [22,23], lowering the likelihood of intraoperative implicit memory formation by 65% [9], and avoiding additional complications [22] compared to no premedication. While low oral doses may not significantly affect patient satisfaction [28], appropriate dosing [28] and alternative administration routes, such as intramuscular or intravenous [14,29], provide additional benefits beyond anxiolysis. These include attenuated cardiovascular responses to laryngoscopy and intubation [30,31], reduced PONV [14,30], and improved patient satisfaction [14,29], all without increasing the risk of postoperative delirium [13]. ...

Preoperative Midazolam and Patient-Centered Outcomes of Older Patients: The I-PROMOTE Randomized Clinical Trial
  • Citing Article
  • December 2023

JAMA Surgery

... [41] Frailty was associated with an increased risk of 30-day mortality. [42] In an Indian prospective registry-based cohort study, the presence of frailty was significantly associated with increased odds of ICU and hospital mortality. Furthermore, frailty was linked with a heightened incidence of severe acute kidney injury, a greater need for non-invasive ventilation, the use of vasopressors, and the initiation of kidney replacement therapy. ...

The association between frailty and ageing: Results from an observational study including 9497 elderly patients
  • Citing Article
  • November 2023

Acta Anaesthesiologica Scandinavica

... Previous studies also suggest that the shape of the ICP pulse waveform may provide information on cerebrospinal compliance [21][22][23][24][25]. Decreasing compliance is associated with a progressive change in the pulse shape from a triphasic, saw-tooth pattern to a rounded or triangular wave with only one defined peak [26]. Recently, we introduced an artificial intelligence-based measure called the pulse shape index (PSI) [27][28][29][30] which is independent of AmpICP and pulse duration and allows for continuous tracking of changes in ICP pulse morphology. Our studies showed that PSI is significantly higher in TBI patients with poor outcomes [30,31], correlates with volumetric imbalance represented by the presence of midline shift and mass lesions [28] and is useful for early prediction of life-threatening ICP crises [32,33]. ...

Relationship between the shape of intracranial pressure pulse waveform and computed tomography characteristics in patients after traumatic brain injury

Critical Care

... Metabolic complications (i.e., abnormalities in renal or liver function and electrolytic imbalances) have previously been shown to be significantly more common in patients receiving high-TIL therapies 12 and an important marker for physiological endotyping 32 . Moreover, in a prior study, serial protein biomarkers (in addition to GCS) were key descriptors for clustering TBI patient trajectories in the ICU 33 . Therefore, the results from these dynamic variables support the links between TIL and pathophysiologyincluding systemic factors (e.g., metabolism and inflammation)-after TBI 7 . ...

Clinical descriptors of disease trajectories in patients with traumatic brain injury in the intensive care unit (CENTER-TBI): a multicentre observational cohort study
  • Citing Article
  • November 2023

The Lancet Neurology

... 4 Other studies similarly noted poor adherence to the CONSORT guidelines, with average reporting rates around 54%, emphasising deficiencies in critical areas like allocation concealment, blinding and sample size estimation. 33 34 Quinn et al compared COVID-19 papers with contemporaneous non-COVID-19 papers and found that COVID-19 research had a higher risk of bias and poorer adherence to reporting guidelines. 35 ...

Poor reporting quality of randomized controlled trials comparing treatments of COVID-19–A retrospective cross-sectional study on the first year of publications

... AKI, a life-threatening complication that can occur following surgery, is defined as a clinical condition caused by a rapid decline in kidney function, which can have multiple underlying causes [3]. Based on a comprehensive international survey, about 20% of patients had AKI after major surgeries [4]. This condition imposes a significant financial burden on the healthcare system worldwide [5]. ...

Epidemiology of surgery associated acute kidney injury (EPIS-AKI): a prospective international observational multi-center clinical study

Intensive Care Medicine

Hichem Makhloufi

·

Rachida Sakhraoui

·

Amel Ouyahia

·

[...]

·

Mercedes Garcia Alvarez

... In another study from 2023, a team in Germany analysed whether the routine use of a tele-emergency medical service is as effective as a conventional physician-based service in terms of intervention-related adverse events. They found that in severe emergency cases, the tele-emergency medical service was indeed non-inferior to the conventional physician-based service regarding the occurrence of adverse events [8]. Despite the potential benefits, healthcare systems struggle with the implementation and dissemination of healthcare innovations. ...

Telemedical support for prehospital emergency medical service in severe emergencies: an open-label randomised non-inferiority clinical trial

Critical Care