Sevoflurane Postconditioning Protects From an Early Neurological Deficit After Subarachnoid Hemorrhage: Results of a Randomized Laboratory Study in Rats.

BACKGROUND: Subarachnoid hemorrhage (SAH) is associated with neurocognitive impairment. Recent data suggest that sevoflurane attenuates edema formation after SAH in rats. However, so far, no information is available about the long-term repair phase, nor if sevoflurane impacts functionality by increasing vascularity. This study tested whether sevoflurane postconditioning would improve long-term neurologic deficit through increased formation of new vessels close to the hemorrhage area. METHODS: Fifty-three animals were subjected to SAH or sham surgery with or without a 2-hour sevoflurane postconditioning (versus propofol anesthesia). Animal survival, including dropout animals due to death or reaching termination criteria, as well as neurologic deficit, defined by the Garcia score, were assessed 2 hours after recovery until postoperative day 14. On day 14, blood samples and brain tissue were harvested. Vessel density was determined by the number of cluster of differentiation 31 (CD31)-positive vessels, and activated glial cells by glial fibrillary acidic protein (GFAP)-positive astrocytes per field of view. RESULTS: The survival rate for sham animals was 100%, 69% in the SAH-propofol and 92% in the SAH-sevoflurane groups. According to the log-rank Mantel-Cox test, survival curves were significantly different ( P = .024). The short-term neurologic deficit was higher in SAH-propofol versus SAH-sevoflurane animals 2 hours after recovery and on postoperative day 1 (propofol versus sevoflurane: 14. 6 ± 3.4 vs 15. 9 ± 2.7 points, P = .034, and 16. 2 ± 3.5 vs 17. 8 ± 0.9 points, P = .015). Overall complete recovery from neurologic deficit was observed on day 7 in both SAH groups (18. 0 ± 0.0 vs 18. 0 ± 0.0 points, P = 1.000). Cortical vascular density increased to 80. 6 ± 15.0 vessels per field of view in SAH-propofol animals (vs 71. 4 ± 10.1 in SAH-sevoflurane, P < .001). Activation of glial cells, an indicator of neuroinflammation, was assessed by GFAP-positive astrocytes GFAP per field of view. Hippocampal GFAP-positive cells were 201 ± 68 vs 179 ± 84 cells per field of view in SAH-propofol versus SAH-sevoflurane animals ( P < .001). CONCLUSIONS: Sevoflurane postconditioning improves survival by 23% (SAH-sevoflurane versus SAH-propofol). The sevoflurane intervention could attenuate the early neurologic deficit, while the long-term outcome was similar across the groups. A higher vascular density close to the SAH area in the propofol group was not associated with improved outcomes.

Effect of Propofol Versus Sevoflurane on Erections during Narcosis in Transurethral Surgery: The PENIS Trial.

Penile erection is unwanted during transurethral interventions as it may be associated with adverse events such as impaired access, prolonged operation time, abortion of the procedure, or a need for ancillary measures to reach penis flaccidity, such as intracorporeal injection of vasoactive drugs. In recent years, anesthesia with propofol has been favored over sevoflurane for environmental reasons. To the best of our knowledge, there have been no prospective randomized clinical trials evaluating the impact of general narcosis medications on the risk of such unwanted penile erections during transurethral surgery. To fill this gap, we have planned a prospective, double-blind (surgeon and patient), single-center, randomized controlled trial. The primary outcome is the occurrence of an intraoperative penile erection. The secondary outcomes are related to the impact of the primary outcome on the surgery, such as changes in operative strategy or operation duration, abortion of the procedure, and adverse events. The plan is to randomize 200 patients undergoing transurethral surgery to receive general anesthesia with either propofol or sevoflurane. The inclusion criteria are men aged <75 yr with an International Index of Erectile Function-5 score of ≥12 points. All men fulfilling the inclusion criteria will be asked to participate. Exclusion criteria are patient characteristics associated with a higher risk of complications with the use of either propofol or sevoflurane. Randomization and treatment allocation will occur after patients give consent. The results will be statistically analyzed using a logistic regression model. This research has received ethical clearance from the local ethics committee (KEK code 2023-01682). The trial is registered on the Swiss National Clinical Trials Portal (SNCTP000005681) and on ClinicalTrial.gov (NCT06378645).

Vitamin B12 status and the risk of developing sepsis in patients with bacterial infection: a prospective observational cohort study.

BACKGROUND: Data have shown that vitamin B12 has immunomodulatory effects via different pathways, which could influence the pathophysiology of sepsis. The objective of this study was to investigate whether vitamin B12 levels, assessed by the measurement of holotranscobalamin (HTC), total vitamin B12 (B12), and methylmalonic acid (MMA, which accumulates in case of B12 deficiency), are associated with the development of sepsis in patients with onset of bacterial infection. METHODS: This was a single-center, prospective observational pilot study. Adult patients who presented to the emergency department with bacterial infection confirmed by a positive microbiological culture result were included in the study and followed up for 6 days to assess whether they developed sepsis or not. The primary objective was to compare HTC concentration in patients who developed sepsis to those who did not develop sepsis. Secondary objectives were the evaluation of B12 and MMA concentrations in those two groups. Multiple logistic regression models were used, with presence of sepsis as the outcome variable, and HTC, B12, and MMA concentrations as predictor variables, separately, and adjusted for potential confounders. RESULTS: From 2019 to 2022, 2131 patients were assessed for eligibility, of whom 100 met the inclusion criteria. One patient was excluded from the analysis due to missing data. Of the 99 patients, 29 developed sepsis. There was no evidence for an association between HTC or B12 concentration and the development of sepsis (OR 0.65, 95% CI 0.31-1.29, p = 0.232, OR 0.84, 95% CI 0.44-1.54, p = 0.584, respectively). There was an association between MMA concentration and the development of sepsis, with a positive effect, i.e. with increasing MMA, the odds for sepsis increased (OR 2.36, 95% CI 1.21-4.87, p = 0.014). This association remained significant when adjusted for confounders (OR 2.72, 95% CI 1.23-6.60, p = 0.018). CONCLUSIONS: Our study found an association between elevated MMA concentration and the development of sepsis. We did not find an association between HTC and B12 concentrations and the development of sepsis. Further, larger studies are warranted, as it could lead to interventional trials investigating whether B12 supplementation provides a clinical benefit to patients with infection or sepsis. TRIAL REGISTRATION: The study was registered on ClinicalTrials.gov under the identifier NCT04008446 on June 17, 2019.

Functionalized magnetic nanoparticles remove donor-specific antibodies (DSA) from patient blood in a first ex vivo proof of principle study.

The presence of donor-specific antibodies (DSA) such as antibodies directed against donor class I human leucocyte antigen (e.g., HLA-A) is a major barrier to kidney transplant success. As a proof of concept, functionalized magnetic nanoparticles have been designed to eliminate DSA from saline, blood and plasma of healthy donors and sensitized patients. Specific HLA-A1 protein was covalently bound to functionalized cobalt nanoparticles (fNP), human serum albumin (HSA) as control. fNP were added to anti-HLA class I-spiked saline, spiked volunteers' whole blood, and to whole blood and plasma of sensitized patients ex vivo. Anti-HLA-A1 antibody levels were determined with Luminex technology. Antibodies' median fluorescent intensity (MFI) was defined as the primary outcome. Furthermore, the impact of fNP treatment on blood coagulation and cellular uptake was determined. Treatment with fNP reduced MFI by 97 ± 2% and by 94 ± 4% (p < 0.001 and p = 0.001) in spiked saline and whole blood, respectively. In six known sensitized anti-HLA-A1 positive patients, a reduction of 65 ± 26% (p = 0.002) in plasma and 65 ± 33% (p = 0.012) in whole blood was achieved. No impact on coagulation was observed. A minimal number of nanoparticles was detected in peripheral mononuclear blood cells. The study demonstrates-in a first step-the feasibility of anti-HLA antibody removal using fNP. These pilot data might pave the way for a new personalized DSA removal technology in the future.

Early sevoflurane sedation in severe COVID-19-related lung injury patients. A pilot randomized controlled trial.

BACKGROUND: This study aimed to assess a potential organ protective effect of volatile sedation in a scenario of severe inflammation with an early cytokine storm (in particular IL-6 elevation) in patients suffering from COVID-19-related lung injury with invasive mechanical ventilation and sedation. METHODS: This is a small-scale pilot multicenter randomized controlled trial from four tertiary hospitals in Switzerland, conducted between April 2020 and May 2021. 60 patients requiring mechanical ventilation due to severe COVID-19-related lung injury were included and randomized to 48-hour sedation with sevoflurane vs. continuous intravenous sedation (= control) within 24 h after intubation. The primary composite outcome was determined as mortality or persistent organ dysfunction (POD), defined as the need for mechanical ventilation, vasopressors, or renal replacement therapy at day 28. Secondary outcomes were the length of ICU and hospital stay, adverse events, routine laboratory parameters (creatinine, urea), and plasma inflammatory mediators. RESULTS: 28 patients were randomized to sevoflurane, 32 to the control arm. The intention-to-treat analysis revealed no difference in the primary endpoint with 11 (39%) sevoflurane and 13 (41%) control patients (p = 0.916) reaching the primary outcome. Five patients died within 28 days in each group (16% vs. 18%, p = 0.817). Of the 28-day survivors, 6 (26%) and 8 (30%) presented with POD (p = 0.781). There was a significant difference regarding the need for vasopressors (1 (4%) patient in the sevoflurane arm, 7 (26%) in the control one (p = 0.028)). Length of ICU stay, hospital stay, and registered adverse events within 28 days were comparable, except for acute kidney injury (AKI), with 11 (39%) sevoflurane vs. 2 (6%) control patients (p = 0.001). The blood levels of IL-6 in the first few days after the onset of the lung injury were less distinctly elevated than expected. CONCLUSIONS: No evident benefits were observed with short sevoflurane sedation on mortality and POD. Unexpectedly low blood levels of IL-6 might indicate a moderate injury with therefore limited improvement options of sevoflurane. Acute renal issues suggest caution in using sevoflurane for sedation in COVID-19. TRIAL REGISTRATION: The trial was registered on ClinicalTrials.gov (NCT04355962) on 2020/04/21.

Sevoflurane Postconditioning Protects From an Early Neurological Deficit After Subarachnoid Hemorrhage: Results of a Randomized Laboratory Study in Rats.

BACKGROUND: Subarachnoid hemorrhage (SAH) is associated with neurocognitive impairment. Recent data suggest that sevoflurane attenuates edema formation after SAH in rats. However, so far, no information is available about the long-term repair phase, nor if sevoflurane impacts functionality by increasing vascularity. This study tested whether sevoflurane postconditioning would improve long-term neurologic deficit through increased formation of new vessels close to the hemorrhage area. METHODS: Fifty-three animals were subjected to SAH or sham surgery with or without a 2-hour sevoflurane postconditioning (versus propofol anesthesia). Animal survival, including dropout animals due to death or reaching termination criteria, as well as neurologic deficit, defined by the Garcia score, were assessed 2 hours after recovery until postoperative day 14. On day 14, blood samples and brain tissue were harvested. Vessel density was determined by the number of cluster of differentiation 31 (CD31)-positive vessels, and activated glial cells by glial fibrillary acidic protein (GFAP)-positive astrocytes per field of view. RESULTS: The survival rate for sham animals was 100%, 69% in the SAH-propofol and 92% in the SAH-sevoflurane groups. According to the log-rank Mantel-Cox test, survival curves were significantly different (P = .024). The short-term neurologic deficit was higher in SAH-propofol versus SAH-sevoflurane animals 2 hours after recovery and on postoperative day 1 (propofol versus sevoflurane: 14. 6 ± 3.4 vs 15. 9 ± 2.7 points, P = .034, and 16. 2 ± 3.5 vs 17. 8 ± 0.9 points, P = .015). Overall complete recovery from neurologic deficit was observed on day 7 in both SAH groups (18. 0 ± 0.0 vs 18. 0 ± 0.0 points, P = 1.000). Cortical vascular density increased to 80. 6 ± 15.0 vessels per field of view in SAH-propofol animals (vs 71. 4 ± 10.1 in SAH-sevoflurane, P < .001). Activation of glial cells, an indicator of neuroinflammation, was assessed by GFAP-positive astrocytes GFAP per field of view. Hippocampal GFAP-positive cells were 201 ± 68 vs 179 ± 84 cells per field of view in SAH-propofol versus SAH-sevoflurane animals (P < .001). CONCLUSIONS: Sevoflurane postconditioning improves survival by 23% (SAH-sevoflurane versus SAH-propofol). The sevoflurane intervention could attenuate the early neurologic deficit, while the long-term outcome was similar across the groups. A higher vascular density close to the SAH area in the propofol group was not associated with improved outcomes.

Assessment of liver function by gadoxetic acid avidity in MRI in a model of rapid liver regeneration in rats.

BACKGROUND: This animal study investigates the hypothesis of an immature liver growth following ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) by measuring liver volume and function using gadoxetic acid avidity in magnetic resonance imaging (MRI) in models of ALPPS, major liver resection (LR) and portal vein ligation (PVL). METHODS: Wistar rats were randomly allocated to ALPPS, LR or PVL. In contrast-enhanced MRI scans with gadoxetic acid (Primovist®), liver volume and function of the right median lobe (=future liver remnant, FLR) and the deportalized lobes (DPL) were assessed until post-operative day (POD) 5. Liver functionFLR/DPL was defined as the inverse value of time from injection of gadoxetic acid to the blood pool-corrected maximum signal intensityFLR/DPL multiplied by the volumeFLR/DPL. RESULTS: In ALPPS (n = 6), LR (n = 6) and PVL (n = 6), volumeFLR and functionFLR increased proportionally, except on POD 1. Thereafter, functionFLR exceeded volumeFLR increase in LR and ALPPS, but not in PVL. Total liver function was significantly reduced after LR until POD 3, but never undercuts 60% of its pre-operative value following ALPPS and PVL. DISCUSSION: This study shows for the first time that functional increase is proportional to volume increase in ALPPS using gadoxetic acid avidity in MRI.

Effects of sevoflurane and its metabolite hexafluoroisopropanol on hypoxia/reoxygenation-induced injury and mitochondrial bioenergetics in murine cardiomyocytes.

Background: The volatile anaesthetic sevoflurane protects cardiac tissue from reoxygenation/reperfusion. Mitochondria play an essential role in conditioning. We aimed to investigate how sevoflurane and its primary metabolite hexafluoroisopropanol (HFIP) affect necrosis, apoptosis, and reactive oxygen species formation in cardiomyocytes upon hypoxia/reoxygenation injury. Moreover, we aimed to describe the similarities in the mode of action in a mitochondrial bioenergetics analysis. Methods: Murine cardiomyocytes were exposed to hypoxia (0.2% O2 for 6 h), followed by reoxygenation (air with 5% CO2 for 2 h) in the presence or absence sevoflurane 2.2% or HFIP 4 mM. Lactate dehydrogenase (LDH) release (necrosis), caspase activation (apoptosis), reactive oxygen species, mitochondrial membrane potential, and mitochondrial function (Seahorse XF analyser) were measured. Results: Hypoxia/reoxygenation increased cell death by 44% (+31 to +55%, P<0.001). Reoxygenation in the presence of sevoflurane 2.2% or HFIP 4 mM increased LDH release only by +18% (+6 to +30%) and 20% (+7 to +32%), respectively. Apoptosis and reactive oxygen species formation were attenuated by sevoflurane and HFIP. Mitochondrial bioenergetics analysis of the two substances was profoundly different. Sevoflurane did not influence oxygen consumption rate (OCR) or extracellular acidification rate (ECAR), whereas HFIP reduced OCR and increased ECAR, an effect similar to oligomycin, an adenosine triphosphate (ATP) synthase inhibitor. When blocking the metabolism of sevoflurane into HFIP, protective effects of sevoflurane - but not of HFIP - on LDH release and caspase were mitigated. Conclusion: Together, our data suggest that sevoflurane metabolism into HFIP plays an essential role in cardiomyocyte postconditioning after hypoxia/reoxygenation injury.

Targeted Large-Volume Lymphocyte Removal Using Magnetic Nanoparticles in Blood Samples of Patients with Chronic Lymphocytic Leukemia: A Proof-of-Concept Study.

In the past, our research group was able to successfully remove circulating tumor cells with magnetic nanoparticles. While these cancer cells are typically present in low numbers, we hypothesized that magnetic nanoparticles, besides catching single cells, are also capable of eliminating a large number of tumor cells from the blood ex vivo. This approach was tested in a small pilot study in blood samples of patients suffering from chronic lymphocytic leukemia (CLL), a mature B-cell neoplasm. Cluster of differentiation (CD) 52 is a ubiquitously expressed surface antigen on mature lymphocytes. Alemtuzumab (MabCampath®) is a humanized, IgG1κ, monoclonal antibody directed against CD52, which was formerly clinically approved for treating chronic lymphocytic leukemia (CLL) and therefore regarded as an ideal candidate for further tests to develop new treatment options. Alemtuzumab was bound onto carbon-coated cobalt nanoparticles. The particles were added to blood samples of CLL patients and finally removed, ideally with bound B lymphocytes, using a magnetic column. Flow cytometry quantified lymphocyte counts before, after the first, and after the second flow across the column. A mixed effects analysis was performed to evaluate removal efficiency. p < 0.05 was defined as significant. In the first patient cohort (n = 10), using a fixed nanoparticle concentration, CD19-positive B lymphocytes were reduced by 38% and by 53% after the first and the second purification steps (p = 0.002 and p = 0.005), respectively. In a second patient cohort (n = 11), the nanoparticle concentration was increased, and CD19-positive B lymphocytes were reduced by 44% (p < 0.001) with no further removal after the second purification step. In patients with a high lymphocyte count (>20 G/L), an improved efficiency of approximately 20% was observed using higher nanoparticle concentrations. A 40 to 50% reduction of B lymphocyte count using alemtuzumab-coupled carbon-coated cobalt nanoparticles is feasible, also in patients with a high lymphocyte count. A second purification step did not further increase removal. This proof-of-concept study demonstrates that such particles allow for the targeted extraction of larger amounts of cellular blood components and might offer new treatment options in the far future.

There is no evidence that carbon dioxide-enriched oxygen before apnea affects the time to arterial desaturation, but it might improve cerebral oxygenation in anesthetized obese patients: a single-blinded randomized crossover trial.

PURPOSE: Carbon dioxide (CO2) increases cerebral perfusion. The effect of CO2 on apnea tolerance, such as after anesthesia induction, is unknown. This study aimed to assess if cerebral apnea tolerance can be improved in obese patients under general anesthesia when comparing O2/Air (95%O2) to O2/CO2 (95%O2/5%CO2). METHODS: In this single-center, single-blinded, randomized crossover trial, 30 patients 18-65 years, with body mass index > 35 kg/m2, requiring general anesthesia for bariatric surgery, underwent two apneas that were preceded by ventilation with either O2/Air or O2/CO2 in random order. After anesthesia induction, intubation, and ventilation with O2/Air or O2/CO2 for 10 min, apnea was performed until the cerebral tissue oxygenation index (TOI) dropped by a relative 20% from baseline (primary endpoint) or oxygen saturation (SpO2) reached 80% (safety abortion criterion). The intervention was then repeated with the second substance. RESULTS: The safety criterion was reached in all patients before cerebral TOI decreased by 20%. The time until SpO2 dropped to 80% was similar in the two groups (+ 6 s with O2/CO2, 95%CI -7 to 19 s, p = 0.37). Cerebral TOI and PaO2 were higher after O2/CO2 (+ 1.5%; 95%CI: from 0.3 to 2.6; p = 0.02 and + 0.6 kPa; 95%CI: 0.1 to 1.1; p = 0.02). CONCLUSION: O2/CO2 improves cerebral TOI and PaO2 in anesthetized bariatric patients. Better apnea tolerance could not be confirmed.

Removal of Circulating Tumor Cells from Blood Samples of Cancer Patients Using Highly Magnetic Nanoparticles: A Translational Research Project.

The count of circulating tumor cells (CTCs) has been associated with a worse prognosis in different types of cancer. Perioperatively, CTCs detach due to mechanical forces. Diagnostic tools exist to detect and isolate CTCs, but no therapeutic technique is currently available to remove CTCs in vivo from unprocessed blood. The aim of this study was to design and test new magnetic nanoparticles to purify whole blood from CTCs. Novel magnetic carbon-coated cobalt (C/Co) nanoparticles conjugated with anti-epithelial cell adhesion molecule (EpCAM) antibodies were synthesized, and their antifouling and separation properties were determined. The newly developed C/Co nanoparticles showed excellent separation and antifouling properties. They efficiently removed tumor cells that were added to healthy subjects' blood samples, through an anti-EpCAM antibody interaction. The nanoparticles did not interact with other blood components, such as lymphocytes or the coagulation system. In blood samples of carcinoma patients suffering from metastatic disease, on average, ≥68% of CTCs were removed. These nanoparticles could prompt the development of a blood purification technology, such as a dialysis-like device, to perioperatively remove CTCs from the blood of cancer patients in vivo and potentially improve their prognosis.

Interleukin-6 Is an Early Plasma Marker of Severe Postoperative Complications in Thoracic Surgery: Exploratory Results From a Substudy of a Randomized Controlled Multicenter Trial.

BACKGROUND: Postoperative complications in surgery are a significant burden, not only for the patients but also economically. While several predicting factors have already been identified, it is still not well known if increased levels of inflammatory markers in the immediate perioperative phase correlate with a higher incidence of postoperative complications. This study aimed to evaluate which patient characteristics and intraoperative parameters correlate with increased plasma values of monocyte chemoattractant protein 1 (MCP-1) and interleukin 6 (IL-6) of thoracic surgery patients. A second goal was to explore whether MCP-1 and IL-6 are associated with the incidence of postoperative complications. We hypothesized that there is a positive association between inflammatory markers and the occurrence of complications within 6 months after surgery. METHODS: This is a substudy of a recent randomized controlled trial, which defined the effect of desflurane versus propofol anesthesia on morbidity and mortality in patients undergoing thoracic surgery. MCP-1 and IL-6 were determined in plasma obtained before and 30 minutes after 1-lung ventilation, 6 hours after surgery, and on postoperative days 1 and 2. Complications were recorded for 6 months. Mixed linear models were used to examine factors associated with MCP-1 and IL-6 levels. Logistic regression models and receiver operating characteristic curves were used to determine the association between MCP-1 and IL-6 and postoperative complications. RESULTS: In the original study, 460 patients were included, MCP-1 and IL-6 levels were determined in 428 patients. MCP-1 was positively associated with the duration of surgery (P = .016), whereas IL-6 levels increased with both the length (P < .001) and invasiveness of lung surgery (thoracoscopic wedge resection or lobectomy versus open lobectomy, P = .005; thoracoscopic wedge resection or lobectomy versus pneumonectomy, P = .021). In an exploratory approach, elevated IL-6 plasma peaks were associated with the occurrence of severe complications defined as Clavien-Dindo score grade ≥IVa during the postoperative phase up to 6 months after thoracic surgery (P = .006). CONCLUSIONS: In summary, this substudy reveals factors, which correlate with high MCP-1 and IL-6 values. Moreover, higher IL-6 seems to be associated with postoperative severe complications. Perioperative IL-6 monitoring might be helpful for risk estimation in the perioperative setting of patients after lung surgery.

Volatile sedation in sepsis: a promising therapeutic approach or a venture doomed to fail?

Preclinical strategies targeting sepsis often had a single target and could not be translated into the clinical setting. Volatile sedation modulates multiple aspects of inflammation and improves sepsis-related survival in animal models. Whether a similar effect can be achieved in humans is unclear. Only a prospective clinical trial will be able to answer this question. The implementation of such a study in times when volatile anaesthetics are the focus of attention because of their greenhouse effect and their carbon dioxide emission will be a challenge, even though the alternative, i.v. sedation, is still insufficiently investigated in this respect.

Inhaled Sedation in Patients with COVID-19-Related Acute Respiratory Distress Syndrome: An International Retrospective Study.

BACKGROUND AND OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic and the shortage of intravenous sedatives has led to renewed interest in inhaled sedation for patients with acute respiratory distress syndrome (ARDS). We hypothesized that inhaled sedation would be associated with improved clinical outcomes in COVID-19 ARDS patients. METHODS: Retrospective international study including mechanically ventilated patients with COVID-19 ARDS who required sedation and were admitted to 10 European and US intensive care units. The primary endpoint of ventilator-free days through day 28 was analyzed using zero-inflated negative binomial regression, before and after adjustment for site, clinically relevant covariates determined according to the univariate results, and propensity score matching. RESULTS: A total of 196 patients were enrolled, 78 of whom died within 28 days. The number of ventilator-free days through day 28 did not differ significantly between the patients who received inhaled sedation for at least 24 h (n = 111) and those who received intravenous sedation only (n = 85), with medians of 0 (interquartile range [IQR] 0-8) and 0 (IQR 0-17), respectively (odds ratio for having zero ventilator-free days through day 28, 1.63, 95% confidence interval [CI], 0.91-2.92, p = 0.10). The incidence rate ratio for the number of ventilator-free days through day 28 if not 0 was 1.13 (95% CI, 0.84-1.52, p = 0.40). Similar results were found after multivariable adjustment and propensity matching. CONCLUSION: The use of inhaled sedation in COVID-19 ARDS was not associated with the number of ventilator-free days through day 28.

A Reproducible Intensive Care Unit-Oriented Endotoxin Model in Rats.

Sepsis and septic shock remain the leading cause of death in intensive care units. Despite significant improvements in sepsis management, mortality still ranges between 20 and 30%. Novel treatment approaches in order to reduce sepsis-related multiorgan failure and death are urgently needed. Robust animal models allow for one or multiple treatment approaches as well as for testing their effect on physiological and molecular parameters. In this article, a simple animal model is presented. First, general anesthesia is induced in animals either with the use of volatile or by intraperitoneal anesthesia. After placement of an intravenous catheter (tail vein), tracheostomy, and insertion of an intraarterial catheter (tail artery), mechanical ventilation is started. Baseline values of mean arterial blood pressure, arterial blood oxygen saturation, and heart rate are recorded. The injection of lipopolysaccharides (1 milligram/kilogram body weight) dissolved in phosphate-buffered saline induces a strong and reproducible inflammatory response via the toll-like receptor 4. Fluid corrections as well as the application of norepinephrine are performed based on well-established protocols. The animal model presented in this article is easy to learn and strongly oriented towards clinical sepsis treatment in an intensive care unit with sedation, mechanical ventilation, continuous blood pressure monitoring, and repetitive blood sampling. Also, the model is reliable, allowing for reproducible data with a limited number of animals in accordance with the 3R (reduce, replace, refine) principles of animal research. While animal experiments in sepsis research cannot easily replaced, repetitive measurements allow for a reduction of animals and keeping septic animals anesthetized diminishes suffering.

Anesthesia and Circulating Tumor Cells in Primary Breast Cancer Patients: A Randomized Controlled Trial.

BACKGROUND: The effect of anesthetic drugs on cancer outcomes remains unclear. This trial aimed to assess postoperative circulating tumor cell counts-an independent prognostic factor for breast cancer-to determine how anesthesia may indirectly affect prognosis. It was hypothesized that patients receiving sevoflurane would have higher postoperative tumor cell counts. METHODS: The parallel, randomized controlled trial was conducted in two centers in Switzerland. Patients aged 18 to 85 yr without metastases and scheduled for primary breast cancer surgery were eligible. The patients were randomly assigned to either sevoflurane or propofol anesthesia. The patients and outcome assessors were blinded. The primary outcome was circulating tumor cell counts over time, assessed at three time points postoperatively (0, 48, and 72 h) by the CellSearch assay. Secondary outcomes included maximal circulating tumor cells value, positivity (cutoff: at least 1 and at least 5 tumor cells/7.5 ml blood), and the association between natural killer cell activity and tumor cell counts. This trial was registered with ClinicalTrials.gov (NCT02005770). RESULTS: Between March 2014 and April 2018, 210 participants were enrolled, assigned to sevoflurane (n = 107) or propofol (n = 103) anesthesia, and eventually included in the analysis. Anesthesia type did not affect circulating tumor cell counts over time (median circulating tumor cell count [interquartile range]; for propofol: 1 [0 to 4] at 0 h, 1 [0 to 2] at 48 h, and 0 [0 to 1] at 72 h; and for sevoflurane: 1 [0 to 4] at 0 h, 0 [0 to 2] at 48 h, and 1 [0 to 2] at 72 h; rate ratio, 1.27 [95% CI, 0.95 to 1.71]; P = 0.103) or positivity. In one secondary analysis, administrating sevoflurane led to a significant increase in maximal tumor cell counts postoperatively. There was no association between natural killer cell activity and circulating tumor cell counts. CONCLUSIONS: In this randomized controlled trial investigating the effect of anesthesia on an independent prognostic factor for breast cancer, there was no difference between sevoflurane and propofol with respect to circulating tumor cell counts over time.