Asterios Tzalavras

Dr. Asterios Tzalavras


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
9 October 2023 in Intensive Care Medicine
Verified
Journal Article
Open access
PDF file
CACarl Thomas Anthon
Carl Thomas Anthon
FPFrédéric Pène
Frédéric Pène
APAnders Perner
Anders Perner
EAElie Azoulay
Elie Azoulay
KPKathryn Puxty
Kathryn Puxty
LRLene Russell
Lene Russell
Purpose Thrombocytopenia (platelet count < 150 × 109/L) is common in intensive care unit (ICU) patients and is likely associated with worse outcomes. In this study we present international contemporary data on thrombocytopenia in ICU patients. Methods We conducted a prospective cohort study in adult ICU patients in 52 ICUs across 10 countries. We assessed frequencies of thrombocytopenia, use of platelet transfusions and clinical outcomes including mortality. We evaluated pre-selected potential risk factors for the development of thrombocytopenia during ICU stay and associations between thrombocytopenia at ICU admission and 90-day mortality using pre-specified logistic regression analyses. Results We analysed 1166 ICU patients; the median age was 63 years and 39.5% were female. Overall, 43.2% (95% confidence interval (CI) 40.4–46.1) had thrombocytopenia; 23.4% (20–26) had thrombocytopenia at ICU admission, and 19.8% (17.6–22.2) developed thrombocytopenia during their ICU stay. Absence of acquired immune deficiency syndrome (AIDS), non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay. Among patients with thrombocytopenia, 22.6% received platelet transfusion(s), and 64.3% of in-ICU transfusions were prophylactic. Patients with thrombocytopenia had higher occurrences of bleeding and death, fewer days alive without the use of life-support, and fewer days alive and out of hospital. Thrombocytopenia at ICU admission was associated with 90-day mortality (adjusted odds ratio 1.7; 95% CI 1.19–2.42). Conclusion Thrombocytopenia occurred in 43% of critically ill patients and was associated with worse outcomes including increased mortality. Platelet transfusions were given to 23% of patients with thrombocytopenia and most were prophylactic.

4 June 2026 in Antibiotics
Verified
Journal Article
Open access
PDF file
Mohamad Amer NashtarMohamad Amer Nashtar
Mohamad Amer Nashtar
JDJutta Dedy
Jutta Dedy
SGStamatina Georgitsi
Stamatina Georgitsi
GGGizem Garipoglu
Gizem Garipoglu
ATAsterios Tzalavras
Asterios Tzalavras
AKAntonios Katsounas
Antonios Katsounas
Objectives: Vancomycin is crucial for treating severe Gram-positive infections, but its narrow therapeutic index complicates dosing. Trough monitoring may inadequately reflect exposure, while AUC-guided dosing, although recommended, is often impractical. Alternative metrics such as the time in therapeutic range (TIR) and volatility index may reflect exposure dynamics. Augmented renal clearance (ARC) further challenges vancomycin therapy in Intensive Care Unit (ICU) settings. This study evaluated trough-based exposure metrics and their associations with ICU mortality and acute kidney injury (AKI). Methods: We retrospectively analyzed 109 ICU patients with sepsis receiving vancomycin. Exposure was assessed using mean trough concentrations, TIR (proportion of troughs within predefined ranges), and the volatility index, defined as the intra-individual standard deviation divided by the mean trough concentration (SD/mean). Outcomes were ICU mortality and AKI. Associations were evaluated using multivariable regression, bootstrap resampling, and restricted cubic splines. Results: TIR >15 was independently associated with higher mortality (adjusted OR 3.88; p = 0.0326) and AKI stage II–III (adjusted OR 5.63; p = 0.0068). Higher mean troughs correlated with AKI stage II–III, whereas higher volatility showed an inverse association (adjusted OR 0.15; p = 0.0240). ARC (4.6%) occurred exclusively in younger patients and predicted subtherapeutic exposure (TIR <10, p = 0.0485). Conclusions: Sustained troughs >15 mg/L were associated with mortality and nephrotoxicity, while the most favorable outcomes were descriptively observed at mean trough levels of approximately 8–12 mg/L, suggesting a possible narrow exposure range that requires prospective validation. These findings highlight the limitations of trough-based monitoring alone; the trough-derived metrics should be regarded as exploratory rather than validated decision-making tools.

6 July 2026 in European Journal of Cancer
Verified
Journal Article
Open access
ATAsterios Tzalavras
Asterios Tzalavras
EBElena Busch
Elena Busch
BBBoris Böll
Boris Böll
GBGernot Beutel
Gernot Beutel
NBNicole Brueder
Nicole Brueder
CLCatherina Lueck
Catherina Lueck
Cancer remains a leading global cause of death, with critically ill cancer patients constituting a substantial proportion of ICU admissions. Historically restrictive ICU admission policies have shifted due to advances in oncology and critical care, leading to declining mortality. However, managing critically ill cancer patients remains complex, requiring collaboration between hematologists/oncologists and intensivists. Emerging evidence on risk assessment, organ support, and tailored critical care underscores the need for updated guidance. This consensus statement provides evidence-based, multidisciplinary recommendations to standardize best practices while allowing for individualized care, aiming to improve survival and quality of life in this high-risk population.

11 December 2023 in Intensive Care Medicine
Verified
Journal Article
Open access
PDF file
CACarl Thomas Anthon
Carl Thomas Anthon
FPFrédéric Pène
Frédéric Pène
APAnders Perner
Anders Perner
EAElie Azoulay
Elie Azoulay
KPKathryn Puxty
Kathryn Puxty
LRLene Russell
Lene Russell
Was given in a misleading wording. Instead of "Absence of acquired immune deficiency syndrome (AIDS), non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay". it should read "Non-AIDS-, non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay.

25 June 2026 in European Journal of Internal Medicine
Verified
Journal Article
Open access
MNMohamad Amer Nashtar
Mohamad Amer Nashtar
MSMohammed Salemdawod
Mohammed Salemdawod
HSHaris Sehovic
Haris Sehovic
GGGizem Garipoglu
Gizem Garipoglu
BÖBetül Ödemis
Betül Ödemis
AKAntonios Katsounas
Antonios Katsounas
Patients with heart failure (HF) are particularly vulnerable to systemic infection; however, the combined impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, viral burden, and emerging viral variants on outcomes in established HF remains incompletely defined. We investigated the independent association between SARS-CoV-2 infection and adverse in-hospital outcomes and evaluated the prognostic relevance of viral load and variant-specific patterns. 2826 consecutive patients hospitalized with documented HF between March 2020 and October 2024 were analyzed. SARS-CoV-2 infection was confirmed by reverse transcription quantitative polymerase chain reaction (RT-qPCR) from nasopharyngeal swabs. Primary outcomes were cardiac decompensation, intensive care unit (ICU) admission, invasive mechanical ventilation, and in-hospital mortality. Secondary outcomes included total and ICU length of stay. Univariable and multivariable regression models were applied to assess associations with clinical outcomes. Viral burden was approximated using median and lowest cycle threshold (Ct) values. SARS-CoV-2 infection (n = 324, 11.5%) was independently associated with cardiac decompensation (adjusted OR 1.66), ICU admission (adjusted OR 1.95), invasive ventilation (adjusted OR 2.76), and in-hospital mortality (adjusted OR 2.60; all p < 0.01). Infection was further associated with prolonged hospitalization (+9.4 days) and ICU stay (+9.1 days; both p < 0.001). Among infected patients, lower median Ct values were independently associated with mortality (adjusted OR per unit increase 0.90; p = 0.0388). Earlier variants demonstrated substantially higher mortality and ICU utilization compared with Omicron sublineages. In hospitalized HF patients, SARS-CoV-2 infection independently increased mortality and healthcare resource utilization. Persistent viral burden and variant-specific heterogeneity further refined risk stratification, underscoring the sustained vulnerability of this high-risk population.

14 August 2026 in Medical Sciences
Verified
Journal Article
Open access
PDF file
Mohamad Amer NashtarMohamad Amer Nashtar
Mohamad Amer Nashtar
PNPatrick Hjalmar Nekarda
Patrick Hjalmar Nekarda
VVVarnavas Varnavas
Varnavas Varnavas
ATAsterios Tzalavras
Asterios Tzalavras
JBJan Best
Jan Best
AKAntonios Katsounas
Antonios Katsounas
Background/Objectives: In-hospital cardiac arrest (IHCA) remains associated with poor survival, while the contribution of arrest etiology and early physiological markers to outcome remains incompletely defined. We examined associations between clinical, neurological, metabolic, and etiological factors and sustained return of spontaneous circulation (ROSC) lasting >20 min, 28-day survival, and 60-day mortality. Methods: This retrospective single-center cohort included 134 adults with confirmed IHCA requiring cardiopulmonary resuscitation at a tertiary university hospital with advanced transplant care between 2011 and 2015. Sustained ROSC and 28-day survival were analyzed using parsimonious Firth penalized logistic regression models, and 60-day mortality using Cox proportional hazards regression. Selected neurological and biomarker analyses were considered exploratory. Results: Sustained ROSC was achieved in 91 patients (67.9%), 33 (24.6%) survived to day 28, and 30 (22.4%) survived to day 60. Initial non-shockable rhythm was associated with lower odds of sustained ROSC (aOR 0.26, 95% CI 0.09–0.69) and 28-day survival (aOR 0.27, 95% CI 0.10–0.68), and with higher 60-day mortality (aHR 1.96, 95% CI 1.25–3.08). The presence of a potentially reversible cause was associated with more favorable outcomes, whereas active hematologic malignancy was associated with higher 60-day mortality (aHR 1.89, 95% CI 1.15–3.10). Exploratory analyses also showed associations of initially dilated pupils with lower 28-day survival and higher lactate with 60-day mortality. Among patients who survived beyond 24 h, higher BNP was associated with subsequent mortality. Conclusions: Non-shockable rhythm and the presence of a potentially reversible cause were consistently associated with outcomes following IHCA, while active hematologic malignancy was associated with poorer longer-term survival. Exploratory findings from lactate, initial pupillary assessment, and BNP may provide complementary prognostic information, although the BNP analysis was limited to patients who survived beyond 24 h. These findings require confirmation in contemporary multicenter cohorts and do not establish validated clinical prediction tools.