The risk of intraoperative venous air embolism from neurosurgical procedures performed in the lounging position: an in-depth analysis of detection, management, and outcomes of 1000 consecutive cases.

OBJECTIVE: The overall benefit of employing a sitting/semisitting position for neurosurgical procedures remains under criticism due to concerns for additional risk, especially the risk of intraoperative venous air embolism (VAE). The aim of this single-center cohort study was to evaluate the frequency and severity of VAEs and associated complications in patients undergoing neurosurgery in the lounging position. METHODS: From 2010 to 2020, 1000 patients, including 172 patients with a patent foramen ovale, underwent surgery in the lounging position for different neurosurgical pathologies. All patients were monitored intraoperatively using continuous transesophageal echocardiography (TEE). The anesthesia team documented any observed incidences of VAEs and scored their severity according to the Tuebingen classification system (TCS) for VAE (TCS-VAE). The patients' clinical condition, radiological findings, and hospital course were subsequently analyzed to assess complications in a retrospective analysis of prospectively collected data. RESULTS: In the cohort of 1000 patients, 5 underwent cervical spine surgery and 995 underwent suboccipital craniotomy. VAE was detected by TEE in 51.4% (95% CI 48.4%-54.5%) of patients, with synchronous changes in end-tidal CO2 (grade 2-5 TCS-VAE) noted in 10.2% (95% CI 8.3%-12.3%). None of the patients presented with hemodynamic instability (grade 5 TCS-VAE). Patients with high-grade VAEs were significantly older (p = 0.02) and had lower BMIs (p = 0.001) than the respective mean value of the cohort. VAE grade was not associated with any of the outcome measures such as Karnofsky Performance Scale score, duration of ventilation, length of intensive care unit stay, and length of hospital stay. Postoperative acute respiratory distress syndrome (ARDS) was diagnosed in 0.3% (95% CI 0.0%-0.7%, n = 3) of all cases, and ARDS was associated with perioperative VAE grade (p = 0.001). No patient suffered a new permanent neurological deficit due to a paradoxical VAE. CONCLUSIONS: In this large cohort, the risk of an intraoperative VAE during neurosurgery in the lounging position was assessed, and contrary to the general perception in the field, no permanent sequelae or fatal adverse events attributable to VAEs were observed. Furthermore, the overall incidence of ARDS was very low. This study clearly establishes that experienced interdisciplinary teams can safely use the lounging position for neurosurgical procedures.

Plexin C1 influences immune response to intracellular LPS and survival in murine sepsis.

BACKGROUND: Intracellular sensing of lipopolysaccharide (LPS) is essential for the immune response against gram-negative bacteria and results in activation of caspase-11 and pyroptotic cell death with fatal consequences in sepsis. We found the neuronal guidance receptor plexin C1 (PLXNC1) influences the intracellular response to LPS. METHODS: We employed a murine model of sepsis via cecal ligation and binding (CLP), using PLXNC1-/- mice and littermate controls, and additionally transfected murine bone-marrow-derived macrophages (BMDMs) from both genotypes with LPS to achieve activation of the noncanonical inflammasome ex vivo. Additionally, we transfected the PLXNC1 ligand SL4c-d in vivo and ex vivo to examine its effect on intracellular LPS response. RESULTS: We found the neuronal guidance receptor PLXNC1 dampens the intracellular response to LPS by interacting with adenylate cyclase 4 (ADCY4) and protein kinase A activity, which in turn diminishes caspase-11 expression. The absence of PLXNC1 results in excessive inflammation marked by increased cytokine release, increased secondary organ injury and reduced sepsis survival in a murine sepsis model induced by CLP. Notably, administration of SL4c-d-peptide ligand of PLXNC1-reduces the inflammatory response during CLP-induced sepsis and improves survival. CONCLUSIONS: These results elucidate a previously unknown mechanism for PLXNC1 suppressing excessive noncanonical inflammasome activity and offer a new potential target for treatment of sepsis with its detrimental effects.

Oblique subcostal transverse abdominis plane block for postoperative pain control in patients undergoing open sublay mesh hernia repair: a prospective double-blind randomized placebo-controlled clinical trial.

BACKGROUND: A bilateral oblique subcostal transverse abdominis plane block may help provide perioperative analgesia and reduce opioid use in patients undergoing sublay mesh hernia repair, but its clinical value is unclear. METHODS: In a single-centre, prospective, placebo-controlled, double-blind study, patients scheduled for sublay mesh hernia repair were randomized to receive oblique subcostal transverse abdominis plane blocks with either 60 ml of 0.375% ropivacaine (n=19) or isotonic saline (placebo, n=17). The primary outcome was patient-controlled total morphine consumption at 8:00 p.m. on the second postoperative day (POD), while secondary outcomes included the total morphine consumption during the post-anesthesia care unit stay and the occurrence of adverse events. RESULTS: Total morphine consumption at 8:00 p.m. on the second POD was higher in patients receiving ropivacaine (39 mg, IQR 22, 62) compared with placebo (24 mg, IQR 7, 39), p value = 0.04. In contrast, the ropivacaine group received 2 mg less morphine during the post-anesthesia care unit stay (4 mg, IQR: 4, 9 mg vs 2 mg, IQR: 2,6 mg, p = 0.04). Patients receiving ropivacaine used more morphine (8:00 p.m. on the first POD until 8:00 a.m. on the second POD: 8 mg, IQR: 4, 18 mg vs 2 mg, IQR: 0, 9 mg, p = 0.01) and reported higher maximum pain scores since the last assessment (8:00 a.m. on the second POD: 5, IQR: 4, 7 vs 4, IQR: 3, 5, p = 0.03). There were no differences in adverse events between groups. CONCLUSIONS: Bilateral oblique subcostal transverse abdominis plane blocks in patients undergoing sublay mesh hernia repair were not associated with a prolonged reduction in patient-controlled total morphine consumption in the evening of the second POD in this study. Rebound pain might explain the additional excess opioid required by the ropivacaine group.

Explainable Boosting Machine approach identifies risk factors for acute renal failure.

BACKGROUND: Risk stratification and outcome prediction are crucial for intensive care resource planning. In addressing the large data sets of intensive care unit (ICU) patients, we employed the Explainable Boosting Machine (EBM), a novel machine learning model, to identify determinants of acute kidney injury (AKI) in these patients. AKI significantly impacts outcomes in the critically ill. METHODS: An analysis of 3572 ICU patients was conducted. Variables such as average central venous pressure (CVP), mean arterial pressure (MAP), age, gender, and comorbidities were examined. This analysis combined traditional statistical methods with the EBM to gain a detailed understanding of AKI risk factors. RESULTS: Our analysis revealed chronic kidney disease, heart failure, arrhythmias, liver disease, and anemia as significant comorbidities influencing AKI risk, with liver disease and anemia being particularly impactful. Surgical factors were also key; lower GI surgery heightened AKI risk, while neurosurgery was associated with a reduced risk. EBM identified four crucial variables affecting AKI prediction: anemia, liver disease, and average CVP increased AKI risk, whereas neurosurgery decreased it. Age was a progressive risk factor, with risk escalating after the age of 50 years. Hemodynamic instability, marked by a MAP below 65 mmHg, was strongly linked to AKI, showcasing a threshold effect at 60 mmHg. Intriguingly, average CVP was a significant predictor, with a critical threshold at 10.7 mmHg. CONCLUSION: Using an Explainable Boosting Machine enhance the precision in AKI risk factors in ICU patients, providing a more nuanced understanding of known AKI risks. This approach allows for refined predictive modeling of AKI, effectively overcoming the limitations of traditional statistical models.

Targeting Gαi2 in neutrophils protects from myocardial ischemia reperfusion injury.

Neutrophils are not only involved in immune defense against infection but also contribute to the exacerbation of tissue damage after ischemia and reperfusion. We have previously shown that genetic ablation of regulatory Gαi proteins in mice has both protective and deleterious effects on myocardial ischemia reperfusion injury (mIRI), depending on which isoform is deleted. To deepen and analyze these findings in more detail the contribution of Gαi2 proteins in resident cardiac vs circulating blood cells for mIRI was first studied in bone marrow chimeras. In fact, the absence of Gαi2 in all blood cells reduced the extent of mIRI (22,9% infarct size of area at risk (AAR) Gnai2-/- → wt vs 44.0% wt → wt; p < 0.001) whereas the absence of Gαi2 in non-hematopoietic cells increased the infarct damage (66.5% wt → Gnai2-/- vs 44.0% wt → wt; p < 0.001). Previously we have reported the impact of platelet Gαi2 for mIRI. Here, we show that infarct size was substantially reduced when Gαi2 signaling was either genetically ablated in neutrophils/macrophages using LysM-driven Cre recombinase (AAR: 17.9% Gnai2fl/fl LysM-Cre+/tg vs 42.0% Gnai2fl/fl; p < 0.01) or selectively blocked with specific antibodies directed against Gαi2 (AAR: 19.0% (anti-Gαi2) vs 49.0% (IgG); p < 0.001). In addition, the number of platelet-neutrophil complexes (PNCs) in the infarcted area were reduced in both, genetically modified (PNCs: 18 (Gnai2fl/fl; LysM-Cre+/tg) vs 31 (Gnai2fl/fl); p < 0.001) and in anti-Gαi2 antibody-treated (PNCs: 9 (anti-Gαi2) vs 33 (IgG); p < 0.001) mice. Of note, significant infarct-limiting effects were achieved with a single anti-Gαi2 antibody challenge immediately prior to vessel reperfusion without affecting bleeding time, heart rate or cellular distribution of neutrophils. Finally, anti-Gαi2 antibody treatment also inhibited transendothelial migration of human neutrophils (25,885 (IgG) vs 13,225 (anti-Gαi2) neutrophils; p < 0.001), collectively suggesting that a therapeutic concept of functional Gαi2 inhibition during thrombolysis and reperfusion in patients with myocardial infarction should be further considered.

Semaphorin 7A coordinates neutrophil response during pulmonary inflammation and sepsis.

ABSTRACT: Pulmonary defense mechanisms are critical for host integrity during pneumonia and sepsis. This defense is fundamentally dependent on the activation of neutrophils during the innate immune response. Recent work has shown that semaphorin 7A (Sema7A) holds significant impact on platelet function, yet its role on neutrophil function within the lung is not well understood. This study aimed to identify the role of Sema7A during pulmonary inflammation and sepsis. In patients with acute respiratory distress syndrome (ARDS), we were able to show a correlation between Sema7A and oxygenation levels. During subsequent workup, we found that Sema7A binds to the neutrophil PlexinC1 receptor, increasing integrins, and L-selectin on neutrophils. Sema7A prompted neutrophil chemotaxis in vitro and the formation of platelet-neutrophil complexes in vivo. We also observed altered adhesion and transmigration of neutrophils in Sema7A-/-animals in the lung during pulmonary inflammation. This effect resulted in increased number of neutrophils in the interstitial space of Sema7A-/- animals but reduced numbers of neutrophils in the alveolar space during pulmonary sepsis. This finding was associated with significantly worse outcome of Sema7A-/- animals in a model of pulmonary sepsis. Sema7A has an immunomodulatory effect in the lung, affecting pulmonary sepsis and ARDS. This effect influences the response of neutrophils to external aggression and might influence patient outcome. This trial was registered at www.ClinicalTrials.gov as #NCT02692118.

Acute kidney disease beyond day 7 after major surgery: a secondary analysis of the EPIS-AKI trial.

PURPOSE: Acute kidney disease (AKD) is a significant health care burden worldwide. However, little is known about this complication after major surgery. METHODS: We conducted an international prospective, observational, multi-center study among patients undergoing major surgery. The primary study endpoint was the incidence of AKD (defined as new onset of estimated glomerular filtration rate (eCFR) < 60 ml/min/1.73 m2 present on day 7 or later) among survivors. Secondary endpoints included the relationship between early postoperative acute kidney injury (AKI) (within 72 h after major surgery) and subsequent AKD, the identification of risk factors for AKD, and the rate of chronic kidney disease (CKD) progression in patients with pre-existing CKD. RESULTS: We studied 9510 patients without pre-existing CKD. Of these, 940 (9.9%) developed AKD after 7 days of whom 34.1% experiencing an episode of early postoperative-AKI. Rates of AKD after 7 days significantly increased with the severity (19.1% Kidney Disease Improving Global Outcomes [KDIGO] 1, 24.5% KDIGO2, 34.3% KDIGO3; P < 0.001) and duration (15.5% transient vs 38.3% persistent AKI; P < 0.001) of early postoperative-AKI. Independent risk factors for AKD included early postoperative-AKI, exposure to perioperative nephrotoxic agents, and postoperative pneumonia. Early postoperative-AKI carried an independent odds ratio for AKD of 2.64 (95% confidence interval [CI] 2.21-3.15). Of 663 patients with pre-existing CKD, 42 (6.3%) had worsening CKD at day 90. In patients with CKD and an episode of early AKI, CKD progression occurred in 11.6%. CONCLUSION: One in ten major surgery patients developed AKD beyond 7 days after surgery, in most cases without an episode of early postoperative-AKI. However, early postoperative-AKI severity and duration were associated with an increased rate of AKD and early postoperative-AKI was strongly associated with AKD independent of all other potential risk factors.

Patient-Related Factors Associated with Adverse Outcomes Following Weaning from Veno-Arterial Extracorporeal Membrane Oxygenation.

BACKGROUND: Veno-arterial extracorporeal membrane oxygenation (vaECMO) removal reflects a critical moment and factors of adverse outcomes are incompletely understood. Thus, we studied various patient-related factors during vaECMO removal to determine their association with outcomes. METHODS: A total of 58 patients from a university hospital were included retrospectively. Demographic, clinical, and echocardiographic parameters were recorded while under vaECMO support, as well as the need for inotropic and vasoactive-inotropic scores (VIS). Successful weaning was defined as 28-day survival without reinitiation of vaECMO. RESULTS: Patient age differed significantly between patients with a successful and a failed vaECMO weaning (54 ± 14 vs. 62 ± 12 years, p = 0.029). In univariable logistic regression, age (OR 0.952 (0.909-0.997), p = 0.038), the necessities for inotropic agents at the time of echocardiography (OR 0.333 (0.113-0.981), p = 0.046), and vaECMO removal (OR 0.266 (0.081-0.877), p = 0.030) as well as the dobutamine dose during removal (OR 0.649 (0.473-0.890), p = 0.007), were significantly associated with a successful weaning from vaECMO. Age (HR 1.048 (1.006-1.091), p = 0.024) and the VIS (HR 1.030 (1.004-1.056), p = 0.025) at the time of vaECMO removal were independently associated with survival in bivariable Cox regression. In Kaplan-Meier analysis, a VIS of >5.1 at vaECMO removal was associated with impaired survival (log-rank p = 0.025). CONCLUSIONS: In this cohort, age and the extent of vasoactive-inotropic agents were associated with adverse outcomes following vaECMO, whereas echocardiographic biventricular function during vaECMO support was not.

Semaphorin 7A is protective during inflammatory peritonitis through integrin receptor signaling.

Introduction: The study explores the role of endothelial Semaphorin 7A (SEMA7A) in inflammatory processes. SEMA7A is known for enhancing inflammation during tissue hypoxia and exhibiting anti-inflammatory properties in the intestinal system during colitis. This research extends the understanding of SEMA7A's function by examining its role in inflammatory peritonitis and intestinal inflammation. Methods: The research involved inducing peritonitis in SEMA7A knockout (SEMA7A-/-) and wild-type (WT) animals through Zymosan A (ZyA) injection. The inflammatory response was assessed by measuring cell count and cytokine release. In parallel, the study investigated the expression of SEMA7A in intestinal epithelial cells under inflammatory stimuli and its impact on interleukin 10 (IL-10) production using an in vitro co-culture model of monocytes and epithelial cells. Additionally, the distribution of SEMA7A target receptors, particularly ITGAV/ITGB1 (CD51/CD29), was analyzed in WT animals. Results: The results revealed that SEMA7A-/- animals exhibited increased inflammatory peritonitis compared to the WT animals. Inflammatory conditions in intestinal epithelial cells led to the induction of SEMA7A. The co-culture experiments demonstrated that SEMA7A induced IL-10 production, which depended on integrin receptors and was independent of PLXNC1 expression. Furthermore, ITGAV/ITGB1 emerged as the predominant SEMA7A receptor in the intestinal area of WT animals. Discussion: These findings underscore the multifaceted role of SEMA7A in inflammatory processes. The differential responses in peritonitis and intestinal inflammation suggest that SEMA7A's function is significantly influenced by the expression and distribution of its target receptors within different organ systems. The study highlights the complex and context-dependent nature of SEMA7A in mediating inflammatory responses.

Early vvECMO implantation may be associated with lower mortality in ARDS.

BACKGROUND: Venovenous extracorporeal membrane oxygenation (vvECMO) is used to treat hypoxia in patients with severe acute respiratory distress syndrome (ARDS). Nevertheless, uncertainty exists regarding the optimal timing of initiation of vvECMO therapy. We aimed to investigate the association between number of days of invasive mechanical ventilation (IMV) prior to vvECMO implantation and mortality. METHODS: In this retrospective observational study, we included patients treated at an academic intensive care unit with vvECMO for severe ARDS. The primary outcome was all-cause 28-day mortality. We conducted a multivariate logistic regression analysis to estimate the association between number of days of IMV prior to vvECMO implantation and mortality after adjustment for confounders. RESULTS: Out of 274 patients who underwent ECMO for severe ARDS, 158 patients (median age: 58 years) with relevant data were included in the analysis. The mean duration of IMV prior to vvECMO was significantly shorter in survivors than in nonsurvivors [survivors median: 1; interquartile range: 1-3; non-survivors median 4; interquartile range: 1-5.75; p = 0.0001). Logistic regression showed an association between the duration of ventilation prior to vvECMO and patient mortality. The odds ratio for the all-cause 28-day mortality and in-hospital mortality was significantly reduced in patients who received vvECMO within the first 5 days of IMV. CONCLUSIONS: Early vvECMO implantation may be associated with lower mortality in ARDS.

Feasibility Assessment of a Biomarker-Guided Kidney-Sparing Sepsis Bundle: The Limiting Acute Kidney Injury Progression In Sepsis Trial.

OBJECTIVES: To determine the feasibility, safety, and efficacy of a biomarker-guided implementation of a kidney-sparing sepsis bundle (KSSB) of care in comparison with standard of care (SOC) on clinical outcomes in patients with sepsis. DESIGN: Adaptive, multicenter, randomized clinical trial. SETTING: Five University Hospitals in Europe and North America. PATIENTS: Adult patients, admitted to the ICU with an indwelling urinary catheter and diagnosis of sepsis or septic shock, without acute kidney injury (acute kidney injury) stage 2 or 3 or chronic kidney disease. INTERVENTIONS: A three-level KSSB based on Kidney Disease: Improving Global Outcomes (KDIGOs) recommendations guided by serial measurements of urinary tissue inhibitor of metalloproteinases-2 and insulin-like growth factor-binding protein 7 used as a combined biomarker [TIMP2]•[IGFBP7]. MEASUREMENTS AND MAIN RESULTS: The trial was stopped for low enrollment related to the COVID-19 pandemic. Nineteen patients enrolled in five sites over 12 months were randomized to the SOC (n = 8, 42.0%) or intervention (n = 11, 58.0%). The primary outcome was feasibility, and key secondary outcomes were safety and efficacy. Adherence to protocol in patients assigned to the first two levels of KSSB was 15 of 19 (81.8%) and 19 of 19 (100%) but was 1 of 4 (25%) for level 3 KSSB. Serious adverse events were more frequent in the intervention arm (4/11, 36.4%) than in the control arm (1/8, 12.5%), but none were related to study interventions. The secondary efficacy outcome was a composite of death, dialysis, or progression of greater than or equal to 2 stages of acute kidney injury within 72 hours after enrollment and was reached by 3 of 8 (37.5%) patients in the control arm, and 0 of 11 (0%) patients in the intervention arm. In the control arm, two patients experienced progression of acute kidney injury, and one patient died. CONCLUSIONS: Although the COVID-19 pandemic impeded recruitment, the actual implementation of a therapeutic strategy that deploys a KDIGO-based KSSB of care guided by risk stratification using urinary [TIMP2]•[IGFBP7] seems feasible and appears to be safe in patients with sepsis.

A key role for platelet GPVI in neutrophil recruitment, migration, and NETosis in the early stages of acute lung injury.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with high morbidity and mortality. Excessive neutrophil infiltration into the pulmonary airspace is the main cause for the acute inflammation and lung injury. Platelets have been implicated in the pathogenesis of ALI/ARDS, but the underlying mechanisms are not fully understood. Here, we show that the immunoreceptor tyrosine-based activation motif-coupled immunoglobulin-like platelet receptor, glycoprotein VI (GPVI), plays a key role in the early phase of pulmonary thrombo-inflammation in a model of lipopolysaccharide (LPS)-induced ALI in mice. In wild-type (WT) control mice, intranasal LPS application triggered severe pulmonary and blood neutrophilia, hypothermia, and increased blood lactate levels. In contrast, GPVI-deficient mice as well as anti-GPVI-treated WT mice were markedly protected from pulmonary and systemic compromises and showed no increased pulmonary bleeding. High-resolution multicolor microscopy of lung sections and intravital confocal microcopy of the ventilated lung revealed that anti-GPVI treatment resulted in less stable platelet interactions with neutrophils and overall reduced platelet-neutrophil complex (PNC) formation. Anti-GPVI treatment also reduced neutrophil crawling and adhesion on endothelial cells, resulting in reduced neutrophil transmigration and alveolar infiltrates. Remarkably, neutrophil activation was also diminished in anti-GPVI-treated animals, associated with strongly reduced formation of PNC clusters and neutrophil extracellular traps (NETs) compared with that in control mice. These results establish GPVI as a key mediator of neutrophil recruitment, PNC formation, and NET formation (ie, NETosis) in experimental ALI. Thus, GPVI inhibition might be a promising strategy to reduce the acute pulmonary inflammation that causes ALI/ARDS.

Platelet formation and activation are influenced by neuronal guidance proteins.

Platelets are anucleate blood cells derived from megakaryocytes. They link the fundamental functions of hemostasis, inflammation and host defense. They undergo intracellular calcium flux, negatively charged phospholipid translocation, granule release and shape change to adhere to collagen, fibrin and each other, forming aggregates, which are key to several of their functions. In all these dynamic processes, the cytoskeleton plays a crucial role. Neuronal guidance proteins (NGPs) form attractive and repulsive signals to drive neuronal axon navigation and thus refine neuronal circuits. By binding to their target receptors, NGPs rearrange the cytoskeleton to mediate neuron motility. In recent decades, evidence has indicated that NGPs perform important immunomodulatory functions and influence platelet function. In this review, we highlight the roles of NGPs in platelet formation and activation.

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

PURPOSE: The incidence, patient features, risk factors and outcomes of surgery-associated postoperative acute kidney injury (PO-AKI) across different countries and health care systems is unclear. METHODS: We conducted an international prospective, observational, multi-center study in 30 countries in patients undergoing major surgery (> 2-h duration and postoperative intensive care unit (ICU) or high dependency unit admission). The primary endpoint was the occurrence of PO-AKI within 72 h of surgery defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Secondary endpoints included PO-AKI severity and duration, use of renal replacement therapy (RRT), mortality, and ICU and hospital length of stay. RESULTS: We studied 10,568 patients and 1945 (18.4%) developed PO-AKI (1236 (63.5%) KDIGO stage 1500 (25.7%) KDIGO stage 2209 (10.7%) KDIGO stage 3). In 33.8% PO-AKI was persistent, and 170/1945 (8.7%) of patients with PO-AKI received RRT in the ICU. Patients with PO-AKI had greater ICU (6.3% vs. 0.7%) and hospital (8.6% vs. 1.4%) mortality, and longer ICU (median 2 (Q1-Q3, 1-3) days vs. 3 (Q1-Q3, 1-6) days) and hospital length of stay (median 14 (Q1-Q3, 9-24) days vs. 10 (Q1-Q3, 7-17) days). Risk factors for PO-AKI included older age, comorbidities (hypertension, diabetes, chronic kidney disease), type, duration and urgency of surgery as well as intraoperative vasopressors, and aminoglycosides administration. CONCLUSION: In a comprehensive multinational study, approximately one in five patients develop PO-AKI after major surgery. Increasing severity of PO-AKI is associated with a progressive increase in adverse outcomes. Our findings indicate that PO-AKI represents a significant burden for health care worldwide.

Development of an Anticipatory Triage-Ranking Algorithm Using Dynamic Simulation of the Expected Time Course of Patients With Trauma: Modeling and Simulation Study.

BACKGROUND: In cases of terrorism, disasters, or mass casualty incidents, far-reaching life-and-death decisions about prioritizing patients are currently made using triage algorithms that focus solely on the patient's current health status rather than their prognosis, thus leaving a fatal gap of patients who are under- or overtriaged. OBJECTIVE: The aim of this proof-of-concept study is to demonstrate a novel approach for triage that no longer classifies patients into triage categories but ranks their urgency according to the anticipated survival time without intervention. Using this approach, we aim to improve the prioritization of casualties by respecting individual injury patterns and vital signs, survival likelihoods, and the availability of rescue resources. METHODS: We designed a mathematical model that allows dynamic simulation of the time course of a patient's vital parameters, depending on individual baseline vital signs and injury severity. The 2 variables were integrated using the well-established Revised Trauma Score (RTS) and the New Injury Severity Score (NISS). An artificial patient database of unique patients with trauma (N=82,277) was then generated and used for analysis of the time course modeling and triage classification. Comparative performance analysis of different triage algorithms was performed. In addition, we applied a sophisticated, state-of-the-art clustering method using the Gower distance to visualize patient cohorts at risk for mistriage. RESULTS: The proposed triage algorithm realistically modeled the time course of a patient's life, depending on injury severity and current vital parameters. Different casualties were ranked by their anticipated time course, reflecting their priority for treatment. Regarding the identification of patients at risk for mistriage, the model outperformed the Simple Triage And Rapid Treatment's triage algorithm but also exclusive stratification by the RTS or the NISS. Multidimensional analysis separated patients with similar patterns of injuries and vital parameters into clusters with different triage classifications. In this large-scale analysis, our algorithm confirmed the previously mentioned conclusions during simulation and descriptive analysis and underlined the significance of this novel approach to triage. CONCLUSIONS: The findings of this study suggest the feasibility and relevance of our model, which is unique in terms of its ranking system, prognosis outline, and time course anticipation. The proposed triage-ranking algorithm could offer an innovative triage method with a wide range of applications in prehospital, disaster, and emergency medicine, as well as simulation and research.

Daptomycin Pharmacokinetics in Blood and Wound Fluid in Critical Ill Patients with Left Ventricle Assist Devices.

Daptomycin is a cyclic lipopeptide antibiotic with bactericidal effects against multidrug-resistant Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE). For critically ill patients, especially in the presence of implants, daptomycin is an important therapeutic option. Left ventricle assist devices (LVADs) can be utilized for intensive care patients with end-stage heart failure as a bridge to transplant. We conducted a single-center prospective trial with critically ill adults with LVAD who received prophylactic anti-infective therapy with daptomycin. Our study aimed to evaluate the pharmacokinetics of daptomycin in the blood serum and wound fluids after LVAD implantation. Daptomycin concentration were assessed over three days using high-performance liquid chromatography (HPLC). We detected a high correlation between blood serum and wound fluid daptomycin concentration at 12 h (IC95%: 0.64 to 0.95; r = 0.86; p < 0.001) and 24 h (IC95%: -0.38 to 0.92; r = 0.76; p < 0.001) after antibiotic administration. Our pilot clinical study provides new insights into the pharmacokinetics of daptomycin from the blood into wound fluids of critically ill patients with LVADs.

Whole-body perfusion improves intraoperative transfusions in neonatal aortic arch surgery.

OBJECTIVES: Whole-body perfusion is the combination of lower body perfusion and antegrade cerebral perfusion. This perfusion technique is used in some centres when performing aortic arch reconstruction surgery in neonates and infants. Several studies have shown intra- and postoperative benefits of this technique. However, no studies have analysed the impact it may have on the transfusion of blood products and coagulation factors. METHODS: We retrospectively analysed 65 consecutive neonates and infants who underwent aortic arch reconstruction surgery from January 2014 to July 2020. Patients operated from 2014 to 2017 underwent surgery with antegrade cerebral perfusion; in patients who underwent surgery from 2017 to 2020 a whole-body perfusion strategy was used. Demographic, intra- and postoperative parameters were compared as well as intraoperative blood product and coagulation factor transfusions, chest-tube output in the first 24 h and postoperative bleeding complications. RESULTS: Both groups required intraoperative transfusion of red blood cells, fresh frozen plasma, and platelets, as well as substitution of coagulation factors. The amount of transfused volumes of red blood cells, fresh frozen plasma and platelets (P-values 0.01, <0.01 and <0.01) and intraoperative transfusions of fibrinogen and von Willebrand factor were significantly lower in the whole-body perfusion group (P-value 0.04 and <0.01). CONCLUSIONS: A whole-body perfusion strategy may lead to fewer intraoperative blood product and coagulation factor transfusions when compared to antegrade cerebral perfusion alone in neonates and infants undergoing complex aortic arch reconstruction surgery.

Impact of P-selectin-PSGL-1 Axis on Platelet-Endothelium-Leukocyte Interactions in Fatal COVID-19.

In critically ill patients infected with SARS-CoV-2, early leukocyte recruitment to the respiratory system was found to be orchestrated by leukocyte trafficking molecules accompanied by massive secretion of proinflammatory cytokines and hypercoagulability. Our study aimed to explore the interplay between leukocyte activation and pulmonary endothelium in different disease stages of fatal COVID-19. Our study comprised 10 COVID-19 postmortem lung specimens and 20 control lung samples (5 acute respiratory distress syndrome, 2 viral pneumonia, 3 bacterial pneumonia, and 10 normal), which were stained for antigens representing the different steps of leukocyte migration: E-selectin, P-selectin, PSGL-1, ICAM1, VCAM1, and CD11b. Image analysis software QuPath was used for quantification of positive leukocytes (PSGL-1 and CD11b) and endothelium (E-selectin, P-selectin, ICAM1, VCAM1). Expression of IL-6 and IL-1ß was quantified by RT-qPCR. Expression of P-selectin and PSGL-1 was strongly increased in the COVID-19 cohort compared with all control groups (COVID-19:Controls, 17:23, P < .0001; COVID-19:Controls, 2:75, P < .0001, respectively). Importantly, P-selectin was found in endothelial cells and associated with aggregates of activated platelets adherent to the endothelial surface in COVID-19 cases. In addition, PSGL-1 staining disclosed positive perivascular leukocyte cuffs, reflecting capillaritis. Moreover, CD11b showed a strongly increased positivity in COVID-19 compared with all controls (COVID-19:Controls, 2:89; P = .0002), indicating a proinflammatory immune microenvironment. Of note, CD11b exhibited distinct staining patterns at different stages of COVID-19 disease. Only in cases with very short disease course, high levels of IL-1ß and IL-6 mRNA were observed in lung tissue. The striking upregulation of PSGL-1 and P-selectin reflects the activation of this receptor-ligand pair in COVID-19, increasing the efficiency of initial leukocyte recruitment, thus promoting tissue damage and immunothrombosis. Our results show that endothelial activation and unbalanced leukocyte migration play a central role in COVID-19 involving the P-selectin-PSGL-1 axis.