PERIODICUMBIOLOGORUM an interdisciplinary international journal established in 1885 by the Croatian Society of Natural Sciences, appears quarterly and provides a forum for publication of works covering all aspects of life sciences.
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Potential long-looped G-quadruplexes in the BCL-2 promoter and their implications in gene regulation
DNA is a highly dynamic polymer composed of nucleotides that typically forms canonical double helix but can also fold into a variety of non-canonical secondary structures under specific conditions. G-quadruplexes (G4s) are an example of such structures that arise from guanine-rich regions and increasingly emerge as key regulators of gene expression. While G4s usually follow a well-established consensus sequence and typically contain short loops, recent evidence indicates that non-standard G4s with long loops may also form and impact gene regulation. In this article, we examine the potential roles of long-looped G4s in the BCL-2 promoter. We summarize known G4-forming regions, highlighting their distinct topologies and regulatory outcomes, and present structural features that suggest extended loops may cause specific molecular recognition. Using custom computational analysis, we identified putative long-looped G4 motifs that conventional algorithms, such as G4Hunter, often overlook due to loop length penalties. Predictions with RNAfold further suggest that some long-looped candidates exhibit stable hairpin-like loops, supporting their potential to fold under physiological conditions. We discuss how long loops may enable unique promoter–enhancer interactions, act as additional interaction sites for transcription factors or ligands and expand opportunities for selective targeting by dual-specific ligands. Altogether, we propose that long-looped G4s represent an underexplored layer of gene regulation with the BCL-2 gene as one example of genes potentially including such G4s.
Copyright (c) 2026 Periodicum Biologorum
Pholiotina intermedia (Agaricales, Basidiomycota), a rare fungal species new to Montenegro
Background and purpose: Fungi are largely understudied in Montenegro. So far, there have been no reliably identified records of Pholiotina species. The described and illustrated record of Pholiotina intermedia contributes to the knowledge of the Montenegrin funga (mycobiota) and the morphological, ecological, and molecular characteristics of this species. Material and methods: The basidiomata were photographed, collected, described, dried, and deposited in two institutional collections. Microscopic characters were observed with a light microscope on dried material mounted in alkaline water solution. Genomic DNA was extracted from dried specimen and full-length ITS gene region was amplified and Sanger sequenced. The obtained ITS rDNA sequence was deposited in the GenBank database (PQ320131). Results: A rare fungal species Pholiotina intermedia is reported for the first time from Montenegro. It was found in old-growth beech forest in the Biogradska Gora National Park. This is the first reliably identified record of Pholiotina species in Montenegro. Macro- and micromorphological description and illustrations, as well as ecological, distributional, and molecular data (ITS sequence) are given. The morphological and molecular characteristics of the species are compared with already known data. Conclusions: Pholiotina intermedia is reliably known only from 10 European countries so far and it is rare in each of these countries. Montenegrin collection has morphological characters that correspond well with the descriptions in the literature. Great efforts are needed to seriously reduce the backlog in the study of Montenegrin funga.
Uterine artery embolization: Future or past in treatment of symptomatic myomas
Objective: To evaluate the effectiveness and potential complications of uterine artery embolization (UAE) as a treatment option for symptomatic uterine fibroids in women of reproductive age. Methods: A retrospective analysis was performed on 66 patients who underwent UAE between January 2017 and December 2023 due to symptomatic fibroids or asymptomatic fibroids with documented growth. Embolization was performed using tris-acryl gelatin Embosphere microspheres (500–900 μm). Treatment outcomes were assessed by resolution of clinical symptoms, presence of myoma infarction, and reduction in total myoma volume, as determined by follow-up magnetic resonance imaging (MRI). Results: Complete symptom resolution was achieved in 85% of patients, while myoma infarction was observed in 74.3% of cases. The mean reduction in uterine volume and dominant fibroid volume was 55.95% and 37.51%, respectively. Conclusions: UAE is a minimally invasive radiological procedure that demonstrates high effectiveness in managing symptomatic uterine fibroids. It may represent a valuable alternative to surgical treatment in carefully selected patients.
Analysis of mitochondrial function and antioxidant capacity in JAK2 V617F-positive chronic myeloproliferative neoplasms
Background and purpose: The JAK2 V617F mutation, found in the majority of chronic myeloproliferative neoplasms (MPNs), leads to constitutive JAK-STAT pathway activation, driving cell proliferation and increased production of reactive oxygen species (ROS). Mitochondrial dysfunction and oxidative stress are implicated in MPN pathogenesis. In the present study, we aimed to elucidate mitochondrial functionality and patterns of antioxidant and electron transport chain gene expression in patients with JAK2 V617F-positive myeloproliferative neoplasms. Materials and methods: The study included 66 JAK2 V617F-positive MPN patients and 30 healthy controls. All participants completed the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-SAF TSS) to assess symptom burden. MitoTracker™ (MT) and Nonyl Acridine Orange (NAO) probes were used for flow cytometric assessment of mitochondrial membrane potential and mass, based on mean fluorescence intensity (MFI). Total RNA was isolated, and expression of SOD2, CAT, SIRT3 and MT-ND1 was quantified by qPCR using TaqMan™ probes and normalized to ACTB using the ΔΔCt method. Results: The MT/NAO MFI ratio, reflecting mitochondrial membrane potential relative to mass, was significantly reduced in JAK2 V617F-positive patients compared to controls (p = 0.003). Antioxidant gene expression (SOD2, SIRT3, CAT) and MT-ND1, a key regulator of oxidative phosphorylation, were markedly downregulated in patients (p < 0.001). Conclusions: We show for the first time that patients with the JAK2 V617F mutation exhibit mitochondrial dysfunction, characterized by increased mitochondrial mass, decreased mitochondrial membrane potential, and impaired oxidative phosphorylation and antioxidant defense. To elucidate the potential genetic background of the observed mitochondrial dysfunction, mitochondrial genes should be assessed by sequencing.
Thinking critically about the quality of airway management is a step forward in routine clinical practice
It is our honour and pleasure to present this double issue of Periodicum Biologorum involving critical reviews and scientific papers of the participants on the quality of airway management in accordance with the theme of the congress. Airway management is primarily a technical skill, but it is unquestionable that the method, and especially the quality method of airway management, makes a difference that improves routine clinical practice in terms of patient safety. Therefore, we believe that this double issue will find interest among a wide population of readers.
Copyright (c) 2025 Periodicum Biologorum
Uncovering species diversity in the subgenus Lasius s. str. (Ruzsky, 1913): A morphological and molecular study from Bosnia and Herzegovina
Background and purpose: Ants are a dominant terrestrial insect group and rank among the most abundant and diverse animals on land, playing significant ecological and economic roles. Due to their global diversity and the high morphological similarity among closely related species, accurate identification of ants can be difficult. The aim of this study was to assess the species status within one of the most important ant groups – Lasius genus, subgenus Lasius s. str. – in Bosnia and Herzegovina, using a combination of morphological and molecular approaches. Materials and methods: Forty-two individuals were collected from four localities and identified using appropriate morphological keys. DNA barcoding was performed to complement morphological identification, and sequences were deposited in GenBank. A Maximum Likelihood phylogenetic tree was constructed using MEGA11, incorporating both the sequences from this study and selected sequences from the BOLD database. Results: We identified three species - Lasius niger, L. platythorax and L. emarginatus, by applying both approaches. Specific dark-brown mesosoma and a new haplotype were recorded for L. emarginatus. Conclusions: The observed morphometric differences and a discovery of a new Lasius emarginatus haplotype suggest that the diversity of species within the subgenus in Bosnia and Herzegovina is greater than previously recognized. Further research is warranted to explore the regional diversity and ecological roles of Lasius species.
AGK2 pre-treatment mitigates hepatic ischemia-reperfusion injury by modulating sirtuin 2 expression and reducing inflammation and apoptosis
Ischemia-reperfusion injury (IRI) significantly impacts liver surgeries and transplantation due to oxidative stress, inflammation, and apoptosis. This study examines the protective effects of 2-cyano-3-[5-(2,5-dichlorophenyl)- 2-furanyl]-N-5-quinolinyl-2-propenamide (AGK2), a Sirtuin 2 (SIRT2) inhibitor, in hepatic IRI using in vitro and in vivo models. In vitro, HepG2 cells underwent hypoxia (1% oxygen for 45 minutes) followed by reoxygenation (21% oxygen for 2 hours) to simulate IRI. AGK2 was administered either 30 minutes before hypoxia (pre-treatment) or immediately after reoxygenation (post-treatment). Western blot analysis showed that IRI reduced SIRT2 expression to 50–60% of baseline levels, while AGK2 pre-treatment restored it to 130–150%, and post-treatment to 110–120%. Pre-treatment significantly reduced NF-κB activation and cleaved Caspase-3 levels, correlating with improved cell viability, as assessed by MTT assay. In vivo, a murine model of hepatic IRI (45 minutes ischemia, 2 hours reperfusion) was used, with AGK2 (20 mg/kg) administered pre- or post-treatment. IRI reduced hepatic SIRT2 expression to 50–60% of baseline, while AGK2 pre-treatment elevated it to 140–160%, and post-treatment to 110–130%. AGK2 pre-treatment significantly decreased NF-κB activation and cleaved Caspase-3 levels in liver tissues, indicating reduced inflammation and apoptosis. These findings suggest that AGK2 protects against hepatic IRI by modulating SIRT2 expression and attenuating inflammatory and apoptotic pathways. Pre-treatment consistently demonstrated superior efficacy compared to post-treatment, highlighting the importance of administration timing. This study supports the potential therapeutic application of AGK2 in mitigating hepatic ischemia-reperfusion injury.
SIRT2 inhibition: A novel approach to modulateTLR4/NF-κB and Nrf2 pathways in post-ICH neuroprotection
Background and purpose: Intracerebral hemorrhage (ICH) is a severe form of stroke associated with high morbidity and mortality. Secondary injury mechanisms, including neuroinflammation and oxidative stress, exacerbate neuronal damage. SIRT2, a NAD+-dependent deacetylase, is implicated in inflammatory and antioxidant responses. This study investigates the role of SIRT2 inhibition in modulating the TLR4/NF-κB inflammatory pathway and the Nrf2 antioxidant pathway in an in vitro post-ICH model. Materials and methods: SH-SY5Y neuronal cells were exposed to lipopolysaccharide (LPS) to induce inflammation and hydrogen peroxide (H₂O₂) to simulate oxidative stress. AGK2, a selective SIRT2 inhibitor, was used to assess its effects on these pathways. Western blotting analyzed the expression of SIRT2, TLR4, NF-κB, Nrf2, HO-1, and NQO1, while realtime PCR quantified antioxidant (HO-1, NQO1) and pro-inflammatory cytokine (TNF-α, IL-6) gene expression. Results: SIRT2 inhibition significantly reduced TLR4 and NF-κB expression while promoting Nrf2 activation and antioxidant gene upregulation. The combination of H₂O₂ and LPS increased pro-inflammatory cytokines, but SIRT2 inhibition mitigated this response, indicating its regulatory role in inflammation and oxidative stress. Conclusions: SIRT2 inhibition effectively modulates inflammatory and antioxidant responses in an in vitro post-ICH model. Targeting SIRT2 may represent a potential therapeutic approach to mitigate secondary brain injury in ICH by balancing neuroinflammatory and oxidative stress pathways. Further studies are needed to explore its clinical relevance in hemorrhagic stroke.
Structural and functional analysis of a novel flavonoid-binding hypothetical protein from Staphylococcus aureus through molecular docking and dynamics
Staphylococcus aureus is a significant human pathogen responsible for a wide range of infections, with increasing antibiotic resistance posing a major global health challenge. Despite extensive genomic characterization, many hypothetical proteins remain functionally unannotated, limiting our understanding of bacterial adaptation and pathogenicity. This study aimed to characterize such hypothetical protein, YP_500302.1, to uncover their potential roles and therapeutic relevance. YP_500302.1 was identified as a 495-amino acid transmembrane protein, predicted to function as a glucosyltransferase. Structural and physicochemical analyses indicated its potential involvement in membrane-associated processes. Molecular docking studies with 35 polyphenols revealed that hesperidin (-9.5 kcal mol−1), naringin (-9.3 kcal mol−1), and rutin (-8.9 kcal mol−1) exhibited the strongest binding affinities. Hydrogen bond analysis over a 10 ns molecular dynamics simulation further supported the dynamic interactions of hesperidin with key residues, particularly ASP32 and THR370. These findings highlight the importance of characterizing hypothetical proteins in S. aureus to identify novel drug targets and combat antibiotic resistance.
Partial decomposition of Tartary buckwheat and grape seed flavonoids during the preparation of pasta
Background and purpose: Grain of Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.) is rich in phenolic substances, especially flavonoid rutin. The grains are used in Asia and Europe mainly to make pasta products. Grape (Vitis vinifera L.) processing, mainly for wine, results in byproducts, including seeds, rich in secondary plant metabolites. Main grape seed flavonoids are catechin and epicatechin. There is a need for applying grape seed flavonoids in human nutrition. As is known, flavonoids could be subjected to metabolic changes during dough processing. Materials and methods: Combined Tartary buckwheat/vinegrape pasta was produced in pasta machine. Starting seed flours and pasta were analyzed by LC-MS performed on UltiMate 3000 UHPLC system, coupled with a triple quadrupole/linear ion trap mass spectrometer. Methanol (Chromasolv LC-MS grade, Fluka, Switzerland) and purified water were used for the preparation of mobile phases, and formic acid (Fluka) was used as modifier. An analytical HPLC column Hypersil GOLD Aq, Thermo 150x2.1, 3 μm, was used with the flow rate of 0.3 mL min–1. A mobile phase consisting of methanol and water, both modified with 0.1% formic acid was used throughout the work. Results: In the present research, it was established that in the dough from the mixture of Tartary buckwheat and grape seed flours it is decomposed a considerable part of Tartary buckwheat flavonoid rutin, and grape seed flavonoids catechin and epicatechin. Conclusion: Procedures for minimizing the loss of flavonoids during the manipulation of combined Tartary buckwheat and grape seed flour dough and preparing pasta are needed.
Visibility of the glottis in children using video and direct laryngoscopy during induction of general anesthesia: a retrospective comparative study
Background and purpose: Hypertrophic tonsils can limit the visibility of glottis as a prerequisite for successful intubation. Although expected, studies have not unequivocally proven that videolaryngoscopy improves the visibility of the glottis in children. The aim of this study was to compare the visibility of the glottis using direct (DL) and video laryngoscopy (VL) during induction of general anesthesia in children undergoing adenotonsillectomy or adenoidectomy. Materials and methods: This retrospective study was performed by reviewing the medical charts of 88 children, up to 8 years of age, who underwent adenotonsillectomy/adenoidectomy in the period from January to December 2024 at the Sveti Duh University Hospital in Zagreb. General data were taken for each patient: age, gender, height and weight; preoperative anesthesiology data; ASA classification, Mallampati; intraoperative anesthesia data: difficulty of manual ventilation (according to Han), glottic visualization according to the Cormack Lehane classification, intubation (orderly, difficult, impossible), type of laryngoscope used, type of mechanical ventilation (volume, pressure) and postoperative data on postoperative respiratory complications. Thirty-eight children had complete data. Results: The Cormack-Lehane classification distribution was similar between the VL and DL (p=0.250). The distribution of glottic visibility according to the Cormack-Lehane classification from 1 to 4 in the VL group (n=13), was as follows: 10 (76.9%), 3 (23.1%), 0 (%), and 0 (0%), while in the DL group (n=25) was as follows: 18 (72%), 3 (12%), 4 (16%), and 0(0%). Conclusion: In our patient sample, VL compared to DL did not increase glottic visibility according to the Cormack-Lehane classificatio
The role of artificial intelligence in airway management: current applications and future perspectives
Background and purpose: Artificial intelligence (AI) is a diverse field within computer science that focuses on creating and enhancing technologies, principles, methods, and application systems designed to replicate and enhance human intelligence. Over the past few decades, AI applications have significantly expanded across various medical fields. Despite the upgraded guidelines, challenges in managing difficult airways persist. Even with advancements in anaesthesia techniques and equipment, serious complications can still arise during the management of difficult airways. A consensus on the most effective method for assessing a difficult airway has not yet been established. Consequently, researchers are increasingly implementing AI and developing algorithms to assist anaesthesiologists and other healthcare professionals. This review aims to provide an overview and analysis of the current applications of AI in anaesthesiology, with a particular focus on difficult airways. Conclusions: The development of AI has the potential to bring significant changes to this field, enabling more accurate and faster assessment of airway conditions, as well as improved monitoring during the intubation process. AI should serve as a supportive tool for physicians, simplifying their work and helping them make more informed decisions.
Extubation of patients with cervical spine injury
Background and purpose: Extubation in patients with cervical spine injury (CSI) is a high-stakes clinical intervention, requiring a nuanced understanding of spinal pathophysiology, respiratory mechanics, and risk mitigation strategies. This review synthesizes the current evidence on the demographics, injury mechanisms, and extubation risks associated with CSI, highlighting the complexities that arise from associated spinal cord injuries, diaphragmatic dysfunction, and airway instability. Results: Epidemiological data reveal a bimodal age distribution and an increasing incidence of CSI due to falls, especially among the elderly. The anatomical vulnerability of the cervical spine and the two-phase pathophysiology of spinal cord injury—primary mechanical insult and secondary inflammatory cascades—complicate respiratory management and timing of extubation. Patients with CSI often face unique extubation challenges, including impaired airway reflexes, agitation, and upper airway edema. Existing guidelines, such as those from the Difficult Airway Society, underscore the need for high-risk extubation protocols, emphasizing preparedness, appropriate sedation, and airway reflex control strategies like remifentanil infusion or delayed extubation in select cases. Several predictors of extubation failure in patients with CSI have been investigated, such as prolonged surgery, vertebral level involvement and blood loss. For ventilator-dependent tetraplegic patients, individualized weaning strategies based on neurological and diaphragmatic function are crucial. The use of adjuncts like cough-assist devices post-extubation is essential for airway secretion clearance. Conclusion: Safe extubation in CSI patients demands a multidisciplinary, protocol-driven approach tailored to individual pathophysiological and surgical risk profiles.
Association of low white blood cell counts, comorbidities, and pneumonia in the surgical intensive care unit
Background and purpose: After the start of the COVID-19 pandemic, emergency admissions to the intensive care unit (ICU) have increased. These patients are often in poor general condition with frequent infections, especially pneumonia. Leukopenia may be associated with infections and a poorer treatment outcome in ICU patients. The aim of this study is to investigate the association of leukopenia with pneumonia, length of mechanical ventilation, length of ICU stay, and mortality in the ICU. Materials and methods: Comorbidity, frequency of pneumonia, and duration of mechanical ventilation (MV) were compared in patients with leukopenia (LP group; n = 58) and a control group (n = 282) of surgical ICU patients. Results: Patients with LP were more likely to be female (55% vs. 31%, P = 0.002), had a higher prevalence of respiratory disease (38% vs. 15.9%), gastrointestinal disease (74% vs. 51) and sepsis (41: 19%%) in comparison to control (P<0.001). In the LP population, 39% of patients had pneumonia, whereas in the control population, the rate was 23.8% (P < 0.023). The median ICU stay was 6 (3-14) vs 3 (2-8) days, P < 0.001, and MV length was 47 (8.25-96) vs 13.9 (3.1-85.9) hours in LP and control patients. Conclusion: Women and patients with respiratory and acute abdominal diseases are at higher risk of developing leukopenia. The incidence of sepsis and pneumonia is high in this population. Microbiological analysis of the causative agents of these infections must be performed promptly, and targeted antimicrobial treatment applied.
Investigating KEAP1-DPP3 interaction in live cells: Challenges and considerations in BiFC assay design
Background and purpose: Kelch-like ECH-associated protein 1 (KEAP1) is a repressor of the transcription factor Nuclear factor erythroid 2-related factor 2 (NRF2), a key regulator of the oxidative stress response. Under basal conditions, the NRF2 monomer is bound by a KEAP1 dimer in a complex with Cullin-3 (CUL3) and E3 ubiquitin-protein ligase RBX1 (RBX1), leading to its ubiquitination and subsequent degradation by the proteasome. One mechanism of NRF2 activation involves competitive protein interactors binding to KEAP1, preventing NRF2 ubiquitination. One such interactor is dipeptidyl peptidase 3 (DPP3), whose binding to KEAP1 reduces NRF2 degradation and promotes its transcriptional activity. We developed bimolecular fluorescence complementation (BiFC) assay for livecell analysis of DPP3-KEAP1 interaction in order to investigate its subcellular localization and determine if BiFC is an appropriate method for the investigation of DPP3’s protein interactions. Materials and methods: We constructed BiFC vectors containing Nand C-terminal fragments of the Venus fluorescent protein and cloned WT DPP3, KEAP1 and DPP3-ΔETGE in all possible topologies. Results: All eight WT DPP3 and KEAP1 vector combinations produced positive BiFC signals and the localization of the signal was in the cytosol; however, three out of eight negative control vector combinations (DPP3-ΔETGE-VenusfN/KEAP1-VenusfC, VenusfC-DPP3-ΔETGE/VenusfNKEAP1 and VenusfN- DPP3-ΔETGE/VenusfC-KEAP1) also yielded false positive signals. Conclusion: BiFC is a useful method for studying protein-protein interactions and their subcellular localization, but careful selection of vector combinations is crucial to avoid false-positive signals.
Reintubation in the intensive care unit: challenges,risks, and strategies for prevention
Background and purpose: Reintubation in the intensive care unit is a critical event linked to increased morbidity, prolonged hospitalization, and higher mortality. It often results from respiratory muscle weakness, airway edema, neurological impairment, or cardiovascular instability. Patients requiring reintubation face elevated risks of ventilator-associated pneumonia, airway trauma, and hemodynamic instability. Preventive strategies such as careful extubation planning, noninvasive ventilation, high-flow nasal cannula, corticosteroids for airway edema, and optimized fluid management can help reduce reintubation rates. A structured, multidisciplinary approach is essential for improving extubation success and patient outcomes. Conclusions: This review examines the causes, risk factors, and consequences of reintubation, along with strategies for prevention and management, emphasizing the importance of evidence-based weaning protocols and advanced monitoring techniques.
Early airway management in patients with severe traumatic brain injury
Background and purpose: Traumatic brain injury (TBI) is the main cause of death and disability in injured patients. Airway management in these patients is challenging because unsuccessful endotracheal intubation (ETI) can lead to hypoxemia, hypercapnia, and consecutive secondary brain damage. The aim of this review is to answer the questions about appropriate airway management in patients with severe TBI. Materials and methods: We searched the PubMed database using keywords of our paper: „airway management“, „traumatic brain injury“ and „intubation”. During the period from January 2010 to January 2025, 213 articles were published, relevant for this review. Discussion: The difficulty of obtaining an airway in patients with TBI is a consequence of presence of airway reflexes and muscular tone, the necessity to maintain cervical spine stabilization, and presence of blood and secretions in the upper airway. Influence of ETI on intracranial pressure and cerebral blood flow can also determine outcome. An alternative way for airway management is the use of supraglottic airway devices. Rapid sequence intubation (RSI) as a form of ETI for patients with severe TBI is an appropriate choice with the use of sedatives, hypnotics, opioid analgesics, and muscle relaxants to prevent an increase in intracranial pressure. ETI in patients with cervical spine injury should be done using manual in-line stabilization and video laryngoscope. Conclusions: Airway management in patients with severe TBI is essential because it can influence mortality. TBI patients with airway compromise must be identified, and airway must be secured early to ensure ventilation and oxygenation.
Airway management in retrosternal goiter surgery, retrospective study
Background and purpose: Retrosternal goiter refers to thyroid enlargement in which the lower pole of the thyroid is not palpable with the neck in a hyperextended position. The presence of a mass in the anterior mediastinum and displacement of the trachea are the risk factors for a difficult airway. The aim of this study was to present our experience with airway management in patients with retrosternal goiter. Materials and methods: We conducted a retrospective observational study of patients undergoing elective retrosternal goiter surgery in a tertiary center over one year. We analyzed the preoperative evaluation data and the planning, techniques and outcome of airway management. Results: From January 1st to December 31st, 2024, a total of 349 patients underwent thyroid surgery at our center. Among 72 patients admitted for goiter surgery, 26 patients were diagnosed with retrosternal goiter. A preoperative computerized tomography scan was performed in most patients and revealed 11 patients with massive retrosternal goiter. Intravenous induction to anesthesia with direct or video laryngoscopy was the preferred method of intubation. No significant complications were recorded. Conclusion: If there are no additional risk factors, intravenous induction of anesthesia and intubation with direct or video laryngoscopy are acceptable methods of airway management in patients with retrosternal goiter. Flexible nasendoscopy and virtual bronchoscopy are valuable methods for airway assessment and may reduce the need for awake fiberoptic intubation in complex cases. However, multicentric studies with larger sample sizes are needed to confirm our findings.
Background: The advancement of diagnostic methods and the identification of new indications have presented the anesthesiology team with the critical task of maintaining patients' airways. It is essential to ensure optimal oxygenation and effectively manage airway bleeding. Methods: A review of relevant literature was conducted to assess the clinical applications, advantages, and limitations of the Univent™ endotracheal tube with an integrated bronchial blocker. Databases such as PubMed, Scopus, and ScienceDirect were searched for peer-reviewed articles published in English. Conclusion: The Univent™ tube with a bronchial blocker (BB) is vital for one-lung ventilation and bronchial isolation. While this tool provides significant benefits in scenarios requiring one-lung ventilation, there are important drawbacks to consider, including the risk of tube displacement, difficulties in placement, limited access for suctioning, and potential complications related to the airway.
Dexamethasone as a part of the multimodal perioperative care for thyroid surgery, literature review
Background and purpose: Thyroidectomies are one of the most common elective surgical procedures in modern medicine. Performed under general anesthesia, thyroidectomies are associated with a high incidence of postoperative nausea and vomiting. Other common complications that increase anxiety among the surgical population are pain, postoperative voice dysfunction, and hypocalcemia. Dexamethasone, as a common adjuvant in anesthesia, is recommended as standard of care for prophylaxis of postoperative nausea and vomiting, as well as in the management of postoperative pain. Recent studies recommended the prophylactic use of dexamethasone in order to prevent hypocalcemia, and voice changes after thyroid surgery. Materials and methods: A literature review with 35 studies included was done to investigate and evaluate the effect of dexamethasone on the postoperative nausea and vomiting, pain, and voice dysfunction in patients undergoing thyroid surgery. Results: Dexamethasone seems to be effective for postoperative nausea and vomiting prophylaxis in patients undergoing thyroid surgery in a preoperative single dose of 8-10 mg intravenously. Dexamethasone may have potential in alleviating pain, but the correct dose needs to be determined. Studies supported the prophylaxis with dexamethasone for voice changes and hypocalcemia, but further research is required. Conclusion: A preoperative single intravenous dose of dexamethasone is a safe and effective method for preventing postoperative nausea and vomiting. Further meta-analyses and high-quality trials are needed to determine the optimal dose for pain relief and to assess its impact on voice changes and hypocalcemia.
Challenges and recommendations for extubation after cesarean delivery
Background and purpose: Extubation is the process of removing the endotracheal tube following general anesthesia and represents a critical moment in perioperative care, especially in pregnant patients undergoing cesarean section. Physiological changes during pregnancy increase the risk of complications during extubation, including rapid desaturation, airway obstruction, aspiration, and the potential need for reintubation. These complications can significantly impact maternal morbidity and prolong hospital stays. The aim of this review is to highlight the specific challenges associated with extubation after cesarean delivery, detail potential complications, and provide guidance for safe and effective extubation practices. Conclusion: Pregnancy leads to significant changes in the respiratory system such as reduced functional residual capacity, increased oxygen consumption, and airway mucosal edema, all of which heighten risks during extubation. Recommendations for safe extubation include thorough preextubation assessment, ensuring complete neuromuscular recovery, performing a quantitative cuff-leak test, continuous peri-extubation monitoring, and utilizing specialized airway equipment in high-risk scenarios. A multidisciplinary approach initiated early in pregnancy or upon identification of airway concerns is crucial for reducing extubation-related complications and ensuring patient safety. Adherence to recommended guidelines can reduce the risk of complications and contribute to the successful outcome of this procedure.
Visibility of the glottis during the induction of general anesthesia in patients with obstructive sleep apnea syndrome: retrospective comparative study of video and direct laryngoscopy
Background and purpose: Patients with obstructive sleep apnea syndrome (OSAS) may present as an anesthetic challenge during the induction of general anesthesia for possible difficult airway management. The aim of this study was to share our experiences with airway management in OSAS patients during general anesthesia using video laryngoscopy (VL) and direct laryngoscopy (DL), hypothesizing that VL provides superior glottic visibility compared to DL. Materials and methods: We conducted a retrospective comparative study including two groups of adult patients with polysomnographically diagnosed OSAS who underwent uvulopalatopharyngoplasty and/or septoplasty under general anesthesia at the Sveti Duh University Hospital in Zagreb, Croatia. The DL group consisted of patients from January 2009 to August 2013, while the VL group included patients from January 2020 to December 2024. A questionnaire was completed for each patient, recording general, preoperative, intraoperative, and postoperative data relevant for airway management. Results: In the VL group (n=91), the distribution of glottic visibility according to the Cormack-Lehane classification from 1 (best view) to 4 (worst view) was as follows: 62 (68.1%) (score 1), 23 (25.3%) (score 2), 6 (6.6%) (score 3), and 0 (0%) (score 4). In the DL group (n=91), glottic visibility according to the Cormack-Lehane classification from 1 to 4 was as follows: 14 (15.4%) (score 1), 51 (56%) (score 2), 25 (27.5%) (score 3), and 1 (1.1%) (score 4). (p <0.001). Conclusions: In our study, VL provided better glottic visibility in adult patients with obstructive sleep apnea compared to DL.
Voice Handicap Index (VHI) changes after endotracheal intubation in head and neck, and abdominal surgery
Background and purpose: Endotracheal intubation can carry a risk of mechanical trauma of laryngeal structures. Common postoperative symptoms can include voice changes, vocal fatigue, hoarseness, stridor, sore throat etc. Injuries can be caused by inappropriately chosen endotracheal tube size, longer duration of surgery, type of surgery, and some patient specific factors. The objective of this study is to examine effects of endotracheal intubation and different types of surgery on subjective voice quality measures in different postoperative time points. Also, some patient and operation specific factors will be examined. Material and methods: Study included 80 adult patients, divided into three groups: parotid gland surgery, total thyroidectomy, and abdominal surgery. Sociodemographic data (age, gender, body mass index) were collected. Voice handicap index was used to assess functional, physical, and emotional impact of voice changes to patients’ lives. Anesthesia parameters were collected in the perioperative period. Results: Significant changes in perceived symptoms were detected in all three groups of subjects, in different forms and duration. Perceived symptoms are the longest in patients who underwent total thyroidectomy, while the highest parameters in the first postoperative measurement are in patients who underwent parotid gland surgery. Conclusions: Endotracheal intubation has an impact on perceived voice changes that occur after surgery in the head and neck area. Changes perceived after abdominal surgery were milder and shorter. Patient and surgery related factors have an important impact on intensity and duration of symptoms.
Biomarkers of inflammation in respiratory tract infections: a narrative review
Background and purpose: Respiratory tract infections (RTIs) are a global public health issue and one of the major causes of morbidity and mortality worldwide, especially in immune sensitive or compromised population. It is particularly challenging to distinguish viral from bacterial RTI based only on the symptoms presentations. Bacterial cultures are the gold standard in detecting the causative pathogens. However, they have several shortcomings such as variable diagnostic sensitivity, a relatively long turnaround time and the fact that not all possible pathogens can be detected using one culture. In such case, tests detecting host-response blood-based biomarkers are a valuable contribution in diagnosis making and patient management. Materials and methods: A literature search was conducted in the PubMed electronic database from January 1st 2005 to March 31st 2025 using the following search terms “Clinical Laboratory Techniques” AND “Serum” AND “Infections” AND “Respiratory tract diseases” AND “Diagnosis” AND “Prognosis”. Randomized,non-randomized studies as well as reviews were taken into consideration. Results: C-reactive protein and procalcitonin are at the present the most robust and widely used biomarkers; however newer biomarkers such as serum calprotectin, pentraxin 3 and presepsin, as well as combinations of different biomarkers with high potential for clinical utility are emerging. Conclusions: Host-response biomarkers of inflammation are useful tools in RTIs management when used together in conjunction with clinical symptoms. Depending on the kinetics of their release into the circulation and their elimination, they can be used as either early markers of inflammation or as a prognostic marker for disease severity and mortality.
Perioperative impact of high-flow nasal oxygenation in obstetric general anesthesia
Background and purpose: High-flow nasal oxygenation (HFNO) is gaining attention in anesthesia for cesarean sections under general anesthesia due to its potential to reduce hypoxemia - a major cause of maternal morbidity and mortality. Pregnant patients face increased risk from anatomical and physiological changes, including airway edema, reduced functional residual capacity, and increased aspiration risk. Traditional preoxygenation with 100% oxygen via a face mask may not provide adequate oxygen reserves, prompting exploration of HFNO as an alternative. This paper reviews current evidence on the use of HFNO preoxygenation during anesthesia induction for cesarean sections. Materials and methods: An extensive literature search was performed to evaluate existing research on HFNO as a preoxygenation technique in obstetric general anesthesia. Results: Eight studies were identified that assess HFNO in this context. While some report inferior performance in achieving optimal end-tidal oxygen fraction compared to face mask methods, others highlight benefits. A 2021 randomized trial found HFNO yielded higher arterial oxygen tension and end tidal oxygen fraction post-intubation. Additionally, a recent multicenter pilot study reported no desaturation events among pregnant patients, supporting HFNO’s safety and potential efficacy. Conclusion: HFNO offers advantages such as prolonged safe apnea time and ease of application. However, its effectiveness in the obstetric population remains insufficiently validated. More robust clinical trials are required before HFNO can be integrated into standard anesthetic protocols for cesarean sections.
Facing the airway challenge: a review of difficult airway guidelines in modern practice
Background and purpose: Airway management remains one of anesthesiology’s most unpredictable challenges. The prediction of a difficult airway extends beyond the scope of standard bedside tests and anthropometric measurements, therefore patients classified as low risk may present with unanticipated challenges in ventilation or tracheal intubation. This review explores the limitations of current predictive tools and provides an overview of the leading national guidelines for unanticipated difficult airway management. Materials and methods: A detailed guideline analysis was performed covering definitions, incidence, risk factors, and recommendations issued by major national and professional societies in the field of airway management. Results: Findings confirm that bedside predictive tests lack accuracy, and most difficult airways are unanticipated. The incidence of the difficult airway varies greatly in the literature, by setting and surgical specialties. Guidelines, though varied in structure, consistently emphasize first-pass success, limited attempts, early alternative device use, and the need for backup strategies and documentation. Conclusions: Airway difficulty is an essential part of pre-operative evaluation but remains largely unpredictable. Although technological innovations improve management, neither history, clinical examination nor widely used bedside tests are consistently reliable predictors. Effective clinical judgment, individualized planning with a ready back-up strategy for a possible failed airway management, together with structured, evidence based guidelines still remain essential. Documentation, teamwork, and adaptable algorithms tailored to environment and clinician preference are key to enhancing patient safety and reducing airway-related adverse events.
Team based performance – key for good airway management in children
Background and purpose: Good quality healthcare is unimaginable without proper patient safety. Which is why securing the airway is undoubtedly the most important lifesaving skill any prehospital and hospital emergency medical service provider possesses, including the anaesthesiologists. Children underlying a procedure needing anaesthesia, especially toddlers and neonates, have a high risk of critical airway incidents. Unfortunately, delayed management of compromised paediatric airway still causes significant perioperative morbidity and mortality. Materials and methods: MEDLINE is used to search the English language literature for articles using the following search terms: “human factors”, “paediatric airway”, “preoperative assessment”, “preparation for airway management”, “difficult intubation”, “difficult airway prediction in children”, “paediatric emergency”, “oxygenation”, “patient safety”. Results: Managing critical/accidental situations with good coordination and cooperation by applying the training received through simulations. Conclusions: The human being may err, and technical skills training is not enough to ensure the desired outcomes. There is a need to develop nontechnical skills such as teamwork capabilities. Leadership and teamwork play a vital role in increasing the capacity of paediatric anaesthesiology educators and training the paediatric anaesthesia workforce, essential for patient safety and patient outcomes in airway management during anaesthesia, perioperative and postoperative care.
Intubation and obesity: key challenges – a narrative review
Background and purpose: Obesity is a complex, multifactorial, chronic disease. It is defined as a body mass index (BMI) of 30 kg/m² or higher. The prevalence of obesity is on the rise worldwide. The aim of this paper is to present the complexity of airway management in obese patients and current recommendations. Materials and methods: We searched the PubMed database using the keywords: “obesity” in combination with either “airway management” or “intubation, intratracheal”. Between February 2020 and January 2025, a total of 34 articles relevant to this review were published. Results and discussion: Obese patients are a challenge for any anesthesiologist due to the increased risk of periprocedural complications. One of the major challenges is maintaining the airway in obese patients. An improved understanding of the specific anatomy of the airway, pathophysiology, and pharmacology of obesity makes it easier
Airway management pharmacology: a narrative review
Background and purpose: The selection of anaesthetics and their correct dosage when securing the airway by endotracheal intubation are crucial for patient safety. In this context, different classes of drugs play an essential role. Intravenous anaesthetics, such as propofol, are often used to induce anaesthesia. Knowledge of the pharmacokinetic and pharmacodynamic characteristics of intravenous anaesthetics is extremely important due to the possibility of adequate drug selection in relation to the patient's condition and the side effects produced by these drugs. Ketamine is an anaesthetic that provides dissociative anaesthesia, analgesia and amnesia, and is often used in emergency situations because of its favourable hemodynamic effects. In recent years, the use of ketamine has undergone significant expansion, as has the study of its anaesthetic effects. Muscle relaxants that facilitate intubation and ventilation during anaesthesia are an essential part of the complex process of establishing the airway. These drugs, in combination with hypnotics and opioid analgesics, facilitate endotracheal intubation. Opioid analgesics, such as fentanyl, are necessary drugs to establish an airway, given that endotracheal intubation is one of the most painful interventions in anaesthesia. for analgesia during procedures and immediate postoperative treatment of acute pain. Benzodiazepines are used in elective airway management with the aim of sedation and anxiety reduction. Conclusions: The correct application of drugs and intubation techniques is directly related to the safety and efficiency of establishing the airway; thus, the quality of healthcare is significantly improved.
Procedural guidelines for endotracheal extubation: insights from a narrative review
Background and purpose: Operating rooms (ORs) and intensive care units (ICUs) are two most common medical environments where endotracheal extubation is conducted. The goal of this publication is to investigate the prevalence, causes, and risk factors of endotracheal extubation and to present current guidelines and protocols for performing safe endotracheal extubation of patients. Materials and methods: A narrative review of guidelines related to endotracheal extubation of patients. Results: Coughing and temporary hypertension are minor side effects of endotracheal extubation. With a mortality rate of about 5%, significant complications, such as extubation failure requiring reintubation, pose serious dangers. Inadequate communication between medical personnel, a lack of backup plans, and certain surgical procedures, especially those involving head and neck surgery, are factors that contribute to extubation failure. Reintubation occurs in 0.1% to 25.7% of cases. Patient features that may impact the outcome of extubation and additional extubation issues include obesity, obstructive sleep apnea, and other comorbidities. The endotracheal extubation method can be improved, and the incidence of post-extubation complications can be minimised to the greatest extent possible by implementing thorough standards and protocols to ensure safe extubation practices, especially for patients undergoing complex surgical operations. Conclusion: the approach to each endotracheal extubation should be carefully planned and personalised. Many measures can help avoid complications from endotracheal extubation. As advances in airway management continue to evolve, future research and guideline development should prioritise the integration of new technologies in medicine.