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Objective To evaluate the benefits and harmful effects of conservative versus liberal oxygen therapy in patients admitted to the Intensive Care Unit (ICU). Design A systematic review and meta-analysis was carried out. Setting ICU. Participants Adult patients (aged 18 years or older) were randomized to either a lower oxygenation target strategy (conservative oxygen therapy) or a higher oxygenation target strategy (liberal oxygen therapy) in the ICU. Interventions Patients received different oxygenation target strategies. Results Ten studies involving 5429 adult patients admitted to the ICU were included in the meta-analysis. The pooled results showed no decreased all-cause mortality at 28 days (RR 0.90; 95%CI 0.75–1.09; p = 0.28), 90 days (RR 1.02; 95%CI 0.92–1.13; p = 0.71) or longest follow-up (RR 0.97; 95%CI 0.88–1.08; p = 0.63) among patients administered conservative oxygen therapy. Secondary outcomes were comparable between the two groups. The results of sensitivity analyses and subgroup analyses were consistent with the main analyses. Conclusion No beneficial or harmful effects of conservative oxygen therapy were found compared to liberal oxygen therapy in relation to all-cause mortality among adult patients in the ICU. Conservative oxygen therapy did not reduce all-cause mortality at 28 days, 90 days or longest follow-up. Other important clinical outcomes were also comparable between the two groups.

Objective: The aim of this study is to compare the intramuscular oxygen saturation results during the short and long distance performances of canoe, kayak and rowing athletes. Material and Methods: 30 male international level and licenced athletes (8 canoeists, 11 kayakers and 11 rowers) are participate to this study; age 20.53±3.23 year, height 181.70±7.90 cm, body weight 78.60±11.22 kg and body mass index 23.73±2.37. The intramuscular oxygen saturation status of athletes were measured using the near infrared spectroscopy technology for 40 second sprint and 4 minutes tests performed on the land with branch-specific ergometers. Data collecting processes were recorded as 5 minute rest, 40 second sprint, 10 minute rest, 4 minute distance performances and 5 minute recovery, in total nearly 25 minute. Results: Comparing the intramuscular oxygen saturation values of canoe, kayak and rowing athletes, no significant difference was found in the decrement rate to minimum, during 40 second sprint for biceps brachii and vastus lateralis (p>0.05). As we compare to 4 minute performances, a significant difference was found in both muscle groups for all three branches. It was seen that the difference was between rowing and canoe athletes, and lower intramuscular oxygen saturation values were found in canoeists compared to rowers (p0,05). Dört dk’lık performansları karşılaştırdığımızda, her üç dal için her iki kas grubunda da anlamlı bir fark bulunmuştur. Farklılığın kürek ve kano sporcuları arasında olduğu görülmüş, kanocularda kürekçilere göre daha düşük kas içi oksijen saturasyon değerleri bulunmuştur (p

Aim: Mechanical chest compression devices in the 30:2 mode generally provide a pause of three seconds to give two insufflations without evidence supporting this pause duration. We aimed to explore the optimal pause duration by measuring the time needed for two insufflations, during advanced life support with manual compressions. Methods: Prospectively collected data in the AmsteRdam REsuscitation STudies (ARREST) registry were analysed, including thoracic impedance signal and waveform capnography from manual defibrillators of the Amsterdam ambulance service. Compression pauses were analysed for number of insufflations, time interval from start of the compression pause to the end of the second insufflation, chest compression pause duration and ventilation subintervals. Results: During 132 out-of-hospital cardiac arrests, 1619 manual chest compression pauses to ventilate were identified. In 1364 (84%) pauses, two insufflations were given. In 28% of these pauses, giving two insufflations took more than three seconds. The second insufflation is completed within 3.8 seconds in 90% and within 5 seconds in 97.5% of these pauses. An increasing likelihood of achieving two insufflations is seen with increasing compression pause duration up to five seconds. Conclusion: The optimal chest compression pause duration for mechanical chest compression devices in the 30:2 mode to provide two insufflations, appears to be five seconds, warranting further studies in the context of mechanical chest compression. A 5-second pause will allow providers to give two insufflations with a very high success rate. In addition, a 5-second pause can also be used for other interventions like rhythm checks and endotracheal intubation.

Extracorporeal membrane oxygenation (ECMO) is helpful in providing ventilatory support when other conventional methods of ventilation fail. We report a case of successful management of advanced tracheal malignancy with impeding airway obstruction where veno-venous ECMO (VV-ECMO) was instituted prior to performing critical endotracheal procedure. After securing the VV-ECMO through right jugular vein and left femoral vein under local anaesthesia, the tracheal stent placement was conducted under flexible bronchoscope and fluoroscope control. Oxygenation and carbon dioxide levels were maintained by the ECMO. VV-ECMO is a useful adjunct in the management of subglottic difficult airway obstruction due to complex tracheal pathology where conventional ventilation may not be possible or adequate.

Extra-corporeal membrane oxygenation (ECMO) can be used to treat patients with severe cardiac and/or pulmonary failure. ECMO has been used during pregnancy, at the time of delivery and in the post-partum period with favorable maternal and fetal outcomes.1 In our case, ECMO was initiated intra-operatively during hemorrhagic shock associated with a caesarean delivery, and accompanied by severe pulmonary edema, mitral regurgitation, hypoxia, and cardiac arrest. Research has shown that there is an optimal timing for ECMO initiation. Favorable outcomes are often seen with early initiation.2 This is especially true in pregnancy, when both maternal and fetal health are at stake.2

Objective Ex vivo lung perfusion has emerged as a novel technique to safely preserve lungs before transplantation. Recent studies have demonstrated an accumulation of inflammatory molecules in the perfusate during ex vivo lung perfusion. These proinflammatory molecules, including damage-associated molecular patterns and inflammatory cytokines, may contribute to acute and chronic allograft dysfunction. At present, ex vivo lung perfusion is performed clinically at normothermic temperature (37°C). The effect of lowering temperature to the subnormothermic range during ex vivo lung perfusion has not been reported. In this study, we hypothesized that lower ex vivo lung perfusion temperature will lead to a reduction in allograft inflammation and result in improved post-transplant graft function. Methods Lewis rat heart-lung blocs underwent 4 hours of ex vivo lung perfusion in 3 temperature groups: 37°C (MP37), 30°C (MP30), and 25°C (MP25). In the control group, lung grafts were preserved by static cold storage before transplantation. After ex vivo lung perfusion or static cold storage, the left lung was transplanted for 2 hours before the animal was killed. Sera and tissue were collected and analyzed. Results There were no differences in partial pressure of arterial oxygenation to fraction of inspired oxygen ratios during 4 hours of ex vivo lung perfusion between temperature groups. Tumor necrosis factor α significantly increased in the MP37 group during ex vivo lung perfusion, whereas this was not seen at lower temperatures. Extracellular DNA and high-mobility group box 1 perfusate concentrations increased significantly during ex vivo lung perfusion in all groups, but the rate of increase was diminished at lower temperature. Two hours post-transplant, there were no significant differences in partial pressure of arterial oxygenation to fraction of inspired oxygen ratios of the lung graft or serum damage-associated molecular pattern levels among groups. On histologic grading after transplantation, greater injury was observed in the MP30 and MP37 groups, but not MP25, when compared with static cold storage. Conclusions Subnormothermic ex vivo lung perfusion at 25°C reduces the production of inflammatory mediators during ex vivo lung perfusion and is associated with reduced histologic graft injury after transplantation.

The use of high-risk renal grafts for transplantation requires the optimization of pretransplant assessment and preservation reconditioning strategies to decrease the organ discard rate and to improve short- and long-term clinical outcomes. Active oxygenation is increasingly recognized to play a central role in dynamic preservation strategies, independent of preservation temperature, to recondition mitochondria and to restore the cellular energy profile. The oxygen-related decrease in mitochondrial succinate accumulation ameliorates the harmful effects of ischemia-reperfusion injury. The differences between normothermic and hypothermic machine perfusion with regard to organ assessment, preservation, and reconditioning, as well as the logistic and economic implications, are factors to take into consideration for implementation at a local level. Therefore, these different techniques should be considered complementary to the perfusion strategy selected depending on functional intention and resource availability. This review provides an overview of the current clinical evidence of normothermic and oxygenated hypothermic machine perfusion, either as a continuous or end-ischemic preservation strategy, and future perspectives.

An inborn term neonate weighing 2600 g developed meconium aspiration syndrome at birth. Baby had respiratory failure requiring high-frequency oscillatory ventilation support at 15 hours of life. He additionally developed hypotension with left ventricular dysfunction noted on point-of-care echocardiography (POCE), which required dopamine and epinephrine infusions. At 28 hours of life, he was started on inhaled nitric oxide (iNO), followed by milrinone due to hypoxaemic respiratory failure and the POCE revealed severe pulmonary artery hypertension (PAH). As PAH was refractory to iNO and milrinone, vasopressin was added which resulted in rapid improvement in oxygenation and normalisation of pulmonary artery pressures. Baby was weaned off from vasoactive support in the next 120 hours. Vasopressin proved to be the rescue agent in this case of iNO refractory PAH without any side effects during therapy. Baby was successfully extubated on day 18 and was discharged with a normal neurological examination finding.

This update describes the different strategies that can be implemented to secure intubation procedure in the ICU through optimisation of preoxygenation, airway management and endotracheal intubation in critically ill patients. These proposals are based on the latest French and international guidelines, as well as on the most recent literature on the subject. They emphasise the need for optimal anticipation and preparation for this period of high risk of complications. They also emphasise the need to take human factors into account, rather than simply introducing new devices or improving technical skills. They emphasise the role of the airway management team and of their communication, and the use of validated protocols and readily available cognitive aids. Proposed optimal management is presented in an algorithm. The importance of limiting attempts, recognising failure early, and moving to the next step in the algorithm are emphasised. They recommend the early use of a videolaryngoscope (if possible, with a remote screen visible to all), and supraglottic devices to oxygenate the patient in case of failure. In case of “can’t intubate-can’t oxygenate situation”, cricothyroidotomy using the scalpel, finger, and bougie procedure is suggested. Additional suggestions are made regarding the management of haemodynamics and peri-intubation mechanical ventilation., Cette mise au point décrit les différentes stratégies qui peuvent être mises en place pour sécuriser l’intubation en réanimation : optimisation de la préoxygénation, de la gestion des voies aériennes et de l’intubation endotrachéale chez des patients en état critique. Ces propositions se basent aussi bien sur les dernières recommandations françaises et internationales, mais également sur la littérature la plus récente sur le sujet. Elles mettent l’accent sur la nécessité d’une anticipation et d’une préparation optimales de cette période à risque important de complications. Elles soulignent également la prise en compte des facteurs humains, plutôt que la simple introduction de nouveaux dispositifs ou l’amélioration des compétences techniques. Elles soulignent le rôle de l’équipe chargée de la gestion des voies aériennes et de la communication, tout en s’appuyant sur des protocoles validés et des aides cognitives immédiatement disponibles. La gestion optimale est présentée dans un algorithme. L’importance de limiter les tentatives, de reconnaître rapidement l’échec et de passer à l’étape suivante de l’algorithme sont mises en avant. Elles recommandent l’utilisation précoce d’un vidéolaryngoscope (si possible avec un écran déporté visible par tous), et des dispositifs supraglottiques pour oxygéner le patient en cas d’échec. En cas de sauvetage, la procédure de cricothyroïdotomie au scalpel, au doigt et au mandrin est suggérée. Des propositions supplémentaires sont faites concernant la gestion de l’hémodynamique et de la ventilation mécanique péri-intubation.

Perfluorocarbons are oxygen-carrying, dense liquids initially intended for the use in partial or total liquid ventilation in patients with severe acute respiratory distress syndrome (ARDS), but did not show beneficial effects in clinical studies. However, perfluorocarbons may be used for lung lavage in severe alveolar proteinosis. In ARDS, oxygenation may be so severely compromised that the use of non-oxygenated perfluorocarbons may not be possible. We report of a case of severe non-resolving ARDS treated with extracorporeal membrane oxygenation (ECMO) to secure oxygenation, using perfluorocarbon in a single instillation to aid the clearance of debris and proteinacous edema.

OBJECTIVE To measure changes in pulmonary perfusion during pulsed inhaled nitric oxide (PiNO) delivery in anesthetized, spontaneously breathing and mechanically ventilated ponies positioned in dorsal recumbency. ANIMALS 6 adult ponies. PROCEDURES Ponies were anesthetized, positioned in dorsal recumbency in a CT gantry, and allowed to breathe spontaneously. Pulmonary artery, right atrial, and facial artery catheters were placed. Analysis time points were baseline, after 30 minutes of PiNO, and 30 minutes after discontinuation of PiNO. At each time point, iodinated contrast medium was injected, and CT angiography was used to measure pulmonary perfusion. Thermodilution was used to measure cardiac output, and arterial and mixed venous blood samples were collected simultaneously and analyzed. Analyses were repeated while ponies were mechanically ventilated. RESULTS During PiNO delivery, perfusion to aerated lung regions increased, perfusion to atelectatic lung regions decreased, arterial partial pressure of oxygen increased, and venous admixture and the alveolar-arterial difference in partial pressure of oxygen decreased. Changes in regional perfusion during PiNO delivery were more pronounced when ponies were spontaneously breathing than when they were mechanically ventilated. CLINICAL RELEVANCE In anesthetized, dorsally recumbent ponies, PiNO delivery resulted in redistribution of pulmonary perfusion from dependent, atelectatic lung regions to nondependent aerated lung regions, leading to improvements in oxygenation. PiNO may offer a treatment option for impaired oxygenation induced by recumbency.

Background Previous studies suggest that prone positioning can increase PaO2/FiO2 and reduce mortality in moderate to severe acute respiratory distress syndrome. Effect of prone positioning and high flow nasal oxygen has been studied individually in COVID-19 patients but their combined effect on patient's outcome is yet to be reported. Methods In this study 120 severe COVID-19 positive patients were included and placed in awake prone positioning with high flow nasal oxygen. The efficacy in improving oxygenation with prone positioning and high flow nasal oxygen were evaluated by blood gas analysis. The primary outcome was a proportion of patients requiring non-invasive ventilation or invasive ventilation. The secondary outcomes were a comparison of arterial blood gas parameters and biochemical inflammatory parameters pre proning, end of first proning and end of last prone position in these patients. Results We found only 35 patients (34.3%) required the need for non-invasive or invasive mechanical ventilation support whereas 67 patients (65.7%) were managed successfully on high flow nasal oxygen along with awake prone positioning (p = 0.001). We found there were statistically significant improvements in arterial blood gas parameters and biochemical inflammatory markers after the end of last prone positioning with high flow nasal oxygen. Conclusions Early application of prone positioning in combination with high flow nasal oxygen may help in avoiding mechanical ventilation by improving oxygenation and biochemical inflammatory markers.

The large-scale dynamics of ocean oxygenation have changed dramatically throughout Earth's history, in step with major changes in the abundance of O2 in the atmosphere and changes to marine nutrient availability. A comprehensive mechanistic understanding of this history requires insights from oceanography, marine geology, geochemistry, geomicrobiology, evolutionary ecology, and Earth system modeling. Here, we attempt to synthesize the major features of evolving ocean oxygenation on Earth through more than 3 billion years of planetary history. We review the fundamental first-order controls on ocean oxygen distribution and summarize the current understanding of the history of ocean oxygenation on Earth from empirical and theoretical perspectives—integrating geochemical reconstructions of oceanic and atmospheric chemistry, genomic constraints on evolving microbial metabolism, and mechanistic biogeochemical models. These changes are used to illustrate primary regimes of large-scale ocean oxygenation and to highlight feedbacks that can act to stabilize and destabilize the ocean–atmosphere system in anoxic, low-oxygen, and high-oxygen states.

Background and purpose Nonspecific neck pain (NNP) is a common idiopathic disorder in the general population that affects the trapezius muscle (TM) and blood supply, thereby compromising the fascial system. Myofascial reorganization (MR) is a physical therapy technique that can influence the dynamics of local fluids reducing excessive muscle tension and capillary constriction, and increasing local blood flow. This study aimed to investigate whether MR improves peripheral muscle oxygenation. Methods This was a quasi-experimental study with an intentional non-probability sample. Fifty participants (women: 36, men: 14) with and without NNP were assigned to either the experimental group (EG: n = 25, with NNP, subjected to MR) or the control group (CG: without NNP, no MR intervention). TM oxygenation was measured using near-infrared spectroscopy (NIRS) before and after a single intervention. In addition, functional disability (CG: 5.48 ± 5.58%/EG: 21.12 ± 7.73%) and neck pain were measured using the neck disability index. The pain pressure threshold (CG: 70.49 ± 32.29 kgf/EG: 51.08 ± 27.65 kgf) and pain intensity (CG: 0.76 ± 1.56/EG: 3.28 ± 2.35) were also measured. All participants were evaluated and reassessed after 10 min. Results The results revealed that immediately after 10 min of MR, the EG exhibited an increase in the oxyhemoglobin level of the medium fibers of the TM (0.72 ± 1.47 vs. −0.14 ± 1.33 mmol/dL, p = 0.01). Conclusion The findings indicate that application of MR for 10 min increases the tissue oxyhemoglobin level in the TM of the group with NNP compared to the CG without NNP.

Contains fulltext : 283427.pdf (Publisher’s version ) (Open Access) Hypoxia is a common feature of solid tumors and is associated with increased tumor progression, resistance to therapy and increased metastasis. Hence, tumor hypoxia is a prognostic factor independent of treatment modality. To survive hypoxia, cells activate macroautophagy/autophagy. Paradoxically, in several cancer types, mutations or loss of essential autophagy genes have been reported that are associated with earlier onset of tumor growth. However, to our knowledge, the phenotypic and therapeutic consequences of autophagy deficiency have remained unexplored. In this study, we determined autophagy-defects in head and neck squamous cell carcinoma (HNSCC) and observed that expression of ATG12 (autophagy related 12) was lost in 25%-40% of HNSCC. In line, ATG12 loss is associated with absence of hypoxia, as determined by pimonidazole immunohistochemistry. Hence, ATG12 loss is associated with improved prognosis after therapy in two independent HNSCC cohorts and 7 additional cancer types. In vivo, ATG12 targeting resulted in decreased hypoxia tolerance, increased necrosis and sensitivity of the tumor to therapy, but in vitro ATG12-deficient cells displayed enhanced survival in nutrient-rich culture medium. Besides oxygen, delivery of glucose was hampered in hypoxic regions in vivo, which increases the reliance of cells on other carbon sources (e.g., L-glutamine). We observed decreased intracellular L-glutamine levels in ATG12-deficient cells during hypoxia and increased cell killing after L-glutamine depletion, indicating a central role for ATG12 in maintaining L-glutamine homeostasis. Our results demonstrate that ATG12(low) tumors represent a phenotypically different subtype that, due to the lowered hypoxia tolerance, display a favorable outcome after therapy.Abbreviations: ARCON:accelerated radiotherapy with carbogen and nicotinamide; ATG: autophagy related; BrdUrd: bromodeoxyuridine; CA9/CAIX: carbonic anhydrase 9; HIF1A/HIF1α: hypoxia inducible factor 1 subunit alpha; HNSCC: head and neck squamous cell carcinoma; HPV: human papilloma virus; HR: hazard ratio; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MEF: mouse embryonic fibroblast; mRNA: messenger ribonucleic acid; PCR: polymerase chain reaction; SLC2A1/GLUT1: solute carrier family 2 member 1; TCGA: the Cancer Genome Atlas; TME: tumor microenvironment; UTR: untranslated region; VEGF: vascular endothelial growth factor.

Background During high-flow nasal cannula (HFNC) therapy, flow plays a crucial role in the physiological effects. However, there is no consensus on the initial flow settings and subsequent titration. Thus, we aimed to systematically synthesize the effects of flows during HFNC treatment. Methods In this systematic review, two investigators independently searched PubMed, Embase, Web of Science, Scopus, and Cochrane for in vitro and in vivo studies investigating the effects of flows in HFNC treatment published in English before July 10, 2022. We excluded studies that investigated the pediatric population ( Results In total, 32,543 studies were identified, and 44 were included. In vitro studies evaluated the effects of flow settings on the fraction of inspired oxygen (FIO2), positive end-expiratory pressure, and carbon dioxide (CO2) washout. These effects are flow-dependent and are maximized when the flow exceeds the patient peak inspiratory flow, which varies between patients and disease conditions. In vivo studies report that higher flows result in improved oxygenation and dead space washout and can reduce work of breathing. Higher flows also lead to alveolar overdistention in non-dependent lung regions and patient discomfort. The impact of flows on different patients is largely heterogeneous. Interpretation Individualizing flow settings during HFNC treatment is necessary, and titrating flow based on clinical findings like oxygenation, respiratory rates, ROX index, and patient comfort is a pragmatic way forward.

Blood oximetry provides a fundamental approach to blood gases for inpatients. Arterial blood gases (ABG) have been considered the gold standard for blood oximetry assessment. Venous blood gas (VBG) evaluation is frequently available and provides a source of a more comfortable method for the assessment of blood oximetry in pediatric patients. Some data provided by the venous blood gas can be additive and offer insights apart from the arterial blood gas. The purpose of this review is to provide an assessment of the performance of VBG in pediatric patients. The study concludes that VBG are helpful tools in assessing oxygenation and ventilation in critically ill children and can be used as a marker of adequacy of systemic oxygen delivery. In the setting of systemic oxygen delivery decrease or oxygen extraction increase, the partial pressure of oxygen on the VBG will decrease. Thus, the partial pressure of oxygen and the corresponding venous saturation can be a marker of systemic oxygen delivery in a variety of illnesses. Simultaneous ABG and VBG comparison can actually lend great insight to not only the respiratory status of a patient but provide an assessment of the adequacy of cardiac output and systemic oxygen delivery.

Made available in DSpace on 2022-04-29T08:37:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Background: The possibility of accurately and continuously measuring arterial oxygen partial pressure (PaO2) in horses may facilitate the management of hypoxaemia during general anaesthesia. Objectives: The aim of this study was to evaluate the ability of a novel fibreoptic sensor to measure PaO2 (PaO2Sensor) continuously and in real time in horses undergoing ventilatory manoeuvres during general anaesthesia. Study design: In vivo experimental study. Methods: Six adult healthy horses were anaesthetised and mechanically ventilated in dorsal recumbency. A fibreoptic sensor was placed in one of the facial arteries through a catheter to continuously measure and record PaO2Sensor. After an alveolar recruitment manoeuvre, a decremental positive end-expiratory pressure (PEEP) titration using 20-minute steps of 5 cm H2O from 20 to 0 cm H2O was performed. An arterial blood sample was collected at 15 minutes of ventilation at each PEEP level for PaO2 measurement using an automated blood gas machine (PaO2Ref). The agreement between PaO2Sensor and PaO2Ref was assessed by Pearson's correlation, Bland-Altman plot and four-quadrant plot analysis. In the last minute of ventilation at each PEEP level, a slow tidal inflation/deflation manoeuvre was performed. Results: The mean relative bias between PaO2Sensor and PaO2Ref was 4% with limits of agreement between −17% and 29%. The correlation coefficient between PaO2Sensor and PaO2Ref was 0.98 (P

Purpose Three continuous dosing strategies of cisatracurium (CIS) for acute respiratory distress syndrome (ARDS) have been described in the literature. After implementation of a ventilator synchrony protocol (VSP), we sought to determine which continuous CIS dosing strategy utilized the least amount of drug without compromising efficacy. Methods We retrospectively reviewed patients with ARDS receiving continuous CIS from January 1, 2013 to December 31, 2018. We categorized patients into one of three dosing strategies: fixed dose (FD), titration based solely on train-of-four (TOF), or the VSP. We documented drug consumption and determined efficacy by comparing the change in PaO2/FiO2 ratio (P/F) and oxygenation index (OI) from baseline up to 48 h. Results A total of 1047 patients were screened, and 189 met inclusion criteria (VSP = 69, TOF = 99, FD = 21). Drug consumption (mg) was significantly lower in the VSP arm: 415 [IQR 318–528] compared to both the TOF: 665 [IQR 472–927] and the FD arms: 1730 [IQR 1695–1800], p < 0.001 for each. The change in P/F and OI from baseline were statistically equivalent at all time points. Conclusion Without impacting efficacy of gas exchange, a protocol using ventilator synchrony for CIS titration required significantly less drug compared to TOF-based titration and a fixed dosing regimen.

The changes in brain perfusion and oxygenation in critical illness, which are thought to contribute to brain dysfunction, are unclear due to the lack of methods to measure these variables. We have developed a technique to chronically measure cerebral tissue perfusion and oxygen tension in unanesthetized sheep. Using this technique, we have determined the changes in cerebral perfusion and Po2 during the development of ovine sepsis. In adult Merino ewes, fiber-optic probes were implanted in the brain, renal cortex, and renal medulla to measure tissue perfusion, oxygen tension (Po2), and temperature, and flow probes were implanted on the pulmonary and renal arteries. Conscious sheep were infused with live Escherichia coli for 24 h, which induced hyperdynamic sepsis; mean arterial pressure decreased (from 85.2 ± 5.6 to 71.5 ± 8.7 mmHg), while cardiac output (from 4.12 ± 0.70 to 6.15 ± 1.26 L/min) and total peripheral conductance (from 48.9 ± 8.5 to 86.8 ± 11.5 mL/min/mmHg) increased ( n = 8, all P < 0.001) and arterial Po2 decreased (from 104 ± 8 to 83 ± 10 mmHg; P < 0.01). Cerebral perfusion tended to decrease acutely, although this did not reach significance, but there was a significant and sustained decrease in cerebral tissue Po2 (from 32.2 ± 10.1 to 18.8 ± 11.7 mmHg) after 3 h and to 22.8 ± 5.2 mmHg after 24 h of sepsis ( P < 0.02). Sepsis induced large reductions in both renal medullary perfusion and Po2 but had no effect in the renal cortex. In ovine sepsis, there is an early decrease in cerebral Po2 that is maintained for 24 h despite minimal changes in cerebral perfusion. Cerebral hypoxia may be one of the factors causing sepsis-induced malaise and lethargy.

background We review our institutional experience with pediatric laryngomalacia (LM) cases and report our experience in patients undergoing supraglottoplasty using the spontaneous respiration using intravenous anesthesia and high-flow nasal oxygen (STRIVE Hi) technique. Methods The medical records of 29 children with LM who visited XX Hospital between January 2017 and March 2019 were retrospectively reviewed. Surgical management was performed using the STRIVE Hi technique. Intraoperative findings and postoperative surgical outcomes, including complications and changes in symptoms and weight, were analyzed. Results Of the total study population of 29 subjects, 20 (68.9%) were female. The patients were divided according to the Onley's classification as follows: type I (n = 13, 44.8%), II (n = 10, 34.5%), and III (n = 6, 20.7%). Twenty-five patients (86.2%) had comorbidities. Seventeen patients (58.6%) underwent microlaryngobronchoscopy under STRIVE Hi anesthesia. Four patients with several desaturation events required rescue oxygenation by intermittent intubation and mask bagging during the STRIVE Hi technique. However, the procedure was completed in all patients without any severe adverse effects. Overall, 15 children (51.7%) underwent supraglottoplasty. Among the subjects who underwent supraglottoplasty, 14 (93.3%) showed improvement of symptoms, and their postoperative weight percentile was significantly increased (p = 0.026). One patient required tracheostomy immediately after supraglottoplasty due to associated neurological disease. Conclusion The STRIVE Hi technique is feasible for supraglottoplasty in LM patients, while type III LM patients with micrognathia or glossoptosis may have a higher risk of requiring rescue oxygenation during the STRIVE Hi technique.

BackgroundThe feasibility and benefits of continuous sustained inflations (SIs) during chest compressions (CCs) during delayed cord clamping (physiological-based cord clamping; PBCC) are not known. We aimed to determine whether continuous SIs during CCs would reduce the time to return of spontaneous circulation (ROSC) and improve post-asphyxial blood pressures and flows in asystolic newborn lambs.MethodsFetal sheep were surgically instrumented immediately prior to delivery at ~139 days’ gestation and asphyxia induced until lambs reached asystole. Lambs were randomised to either immediate cord clamping (ICC) or PBCC. Lambs then received a single SI (SIsing; 30 s at 30 cmH2O) followed by intermittent positive pressure ventilation, or continuous SIs (SIcont: 30 s duration with 1 s break). We thus examined 4 groups: ICC +SIsing, ICC +SIcont, PBCC +SIsing, and PBCC +SIcont. Chest compressions and epinephrine administration followed international guidelines. PBCC lambs underwent cord clamping 10 min after ROSC. Physiological and oxygenation variables were measured throughout.ResultsThe time taken to achieve ROSC was not different between groups (mean (SD) 4.3±2.9 min). Mean and diastolic blood pressure was higher during chest compressions in PBCC lambs compared with ICC lambs, but no effect of SIs was observed. SIcontsignificantly reduced pulmonary blood flow, diastolic blood pressure and oxygenation after ROSC compared with SIsing.ConclusionWe found no significant benefit of SIcontover SIsingduring CPR on the time to ROSC or on post-ROSC haemodynamics, but did demonstrate the feasibility of continuous SIs during advanced CPR on an intact umbilical cord. Longer-term studies are recommended before this technique is used routinely in clinical practice.

OBJECTIVE To evaluate the effect of inhaled nitric oxide (iNO) combined with high-frequency oscillatory ventilation (HFOV) in the treatment of infants with acute hypoxemic respiratory failure (AHRF) and pulmonary hypertension (PH) after congenital heart surgery. METHODS A retrospective study was conducted on 63 infants with AHRF and PH after congenital heart surgery in our cardiac intensive care unit (CICU) from January 2020 to March 2021. A total of 24 infants in the A group were treated with HFOV combined with iNO, and 39 infants in the B group were treated with HFOV. Relevant clinical data were collected. RESULTS Comparing the two groups, the improvement of the oxygenation index, PaO2 and PaO2 /FiO2 was more obvious for patients in the A group than for those in the B group after intervention (p

This study aimed at investigating the mechanisms underlying the oxygenation response to proning and recruitment maneuvers in coronavirus disease 2019 (COVID-19) pneumonia. Twenty-five patients with COVID-19 pneumonia, at variable times since admission (from 1 to 3 weeks), underwent computed tomography (CT) lung scans, gas-exchange and lung-mechanics measurement in supine and prone positions at 5 cmH2O and during recruiting maneuver (supine, 35 cmH2O). Within the non-aerated tissue, we differentiated the atelectatic and consolidated tissue (recruitable and non-recruitable at 35 cmH2O of airway pressure). Positive/negative response to proning/recruitment was defined as increase/decrease of PaO2/FiO2. Apparent perfusion ratio was computed as venous admixture/non aerated tissue fraction. The average values of venous admixture and PaO2/FiO2 ratio were similar in supine-5 and prone-5. However, the PaO2/FiO2 changes (increasing in 65% of the patients and decreasing in 35%, from supine to prone) correlated with the balance between resolution of dorsal atelectasis and formation of ventral atelectasis (p = 0.002). Dorsal consolidated tissue determined this balance, being inversely related with dorsal recruitment (p = 0.012). From supine-5 to supine-35, the apparent perfusion ratio increased from 1.38 ± 0.71 to 2.15 ± 1.15 (p = 0.004) while PaO2/FiO2 ratio increased in 52% and decreased in 48% of patients. Non-responders had consolidated tissue fraction of 0.27 ± 0.1 vs. 0.18 ± 0.1 in the responding cohort (p = 0.04). Consolidated tissue, PaCO2 and respiratory system elastance were higher in patients assessed late (all p

Providing supplemental oxygen to hospitalized adults is a frequent practice and can be administered via a variety of devices. Oxygen therapy has evolved over the years, and clinicians should follow evidence-based practices to provide maximum benefit and avoid harm. This systematic review and subsequent clinical practice guidelines were developed to answer questions about oxygenation targets, monitoring, early initiation of high-flow oxygen (HFO), benefits of HFO compared to conventional oxygen therapy, and humidification of supplemental oxygen. Using a modification of the RAND/UCLA Appropriateness Method, 7 recommendations were developed to guide the delivery of supplemental oxygen to hospitalized adults: (1) aim for SpO2 range of 94-98% for most hospitalized patients (88-92% for those with COPD), (2) the same SpO2 range of 94-98% for critically ill patients, (3) promote early initiation of HFO, (4) consider HFO to avoid escalation to noninvasive ventilation, (5) consider HFO immediately postextubation to avoid re-intubation, (6) either HFO or conventional oxygen therapy may be used with patients who are immunocompromised, and (7) consider humidification for supplemental oxygen when flows > 4 L/min are used.

Hypoxia is the most frequently occurring adverse effect during endoscopic retrograde cholangiopancreatography (ERCP) under sedation; thus, oxygen must be properly supplied to prevent a reduction of oxygen saturation. In this study, we intend to verify the preventive effect for hypoxia during ERCP, using a high-flow nasal cannula (HFNC), in elderly patients. As a multicenter prospective randomized trial, patients who underwent ERCP with propofol-based sedation were randomly assigned into two groups: Patients in the HFNC group were supplied with oxygen via an HFNC, and those in the standard nasal cannula group were supplied with oxygen via a low-flow nasal cannula. The co-primary end points were the lowest oxygen saturation rate and hypoxia during the overall procedure. A total of 187 patients (HFNC group: 95; standard nasal cannula group: 92) were included in the analysis. Unexpected hypoxia events were more frequently observed among patients in the standard nasal cannula group than among patients in the HFNC group (13% vs. 4%, odds ratio 3.41, 95% confidence interval 1.06–11.00, p = 0.031). The mean of the lowest oxygen saturation rate during ERCP was significantly lower in the standard nasal cannula group than in the HFNC group (95% vs. 97%, p = 0.002). Oxygen supplementation with an HFNC can prevent oxygen desaturation and hypoxia events in patients undergoing ERCP under sedation. Trial registration Clinical Research Information Service (CRIS; KCT0004960).

Background: Stepwise lung recruitment maneuvers (LRMs) may be used in ventilated preterm infants. However, its use in high-frequency oscillation with volume guarantee (HFO-VG) is not well studied. Methods: Preterm infants treated with HFO-VG who had LRMs were identified. Patient and respiratory parameters were recorded. Results: Ten infants, median GA 25+6 (IQR 24+2–27+0) weeks, and 21 LRMs were identified. LRMs were performed at a median age of 26 days, with a starting MAP of 16 (14–17) cm H2O and the highest MAP of 23.5 (22.0–24.8) cm H2O. Most (76%) resulted in immediate improved SpO2/FiO2. There were no sustained differences in median oxygen saturation index (8.4 vs. 9, p = 0.09), SpO2/FiO2 (1.8 vs. 1.8, p = 0.8), ∆P (21 vs. 23, p = 0.64), or transcutaneous CO2 (58 vs. 60, p = 0.84) in 24 h before and after LRMs. Conclusions: In preterm infants with evolving bronchopulmonary dysplasia, LRMs on HFO-VG did not result in sustained improvement to oxygenation or ventilation.

Objective To assess and compare the effect of intraoperative stepwise alveolar recruitment manoeuvres (ARMs), followed by individualized positive end-expiratory pressure (PEEP), defined as PEEP at maximal respiratory system compliance + 2 cmH2O (PEEPmaxCrs+2), with that of spontaneous ventilation (SV) and controlled mechanical ventilation (CMV) without ARM or PEEP on early postoperative arterial oxygenation in anaesthetized healthy dogs. Study design Prospective, randomized, nonblinded clinical study. Animals A total of 32 healthy client-owned dogs undergoing surgery in dorsal recumbency. Methods Dogs were ventilated intraoperatively (inspired oxygen fraction: 0.5) with one of the following strategies: SV, CMV alone, and CMV with PEEPmaxCrs+2 following a single ARM (ARM1) or two ARMs (ARM2, the second ARM at the end of surgery). Arterial blood gas analyses were performed before starting the ventilatory strategy, at the end of surgery, and at 5, 10, 15, 30 and 60 minutes after extubation while breathing room air. Data were analysed using Kruskal-Wallis and Friedman tests (p Results At any time point after extubation, PaO2 was not significantly different between groups. At 5 minutes after extubation, PaO2 was 95.1 (78.1–104.0), 93.8 (88.3–104.0), 96.9 (86.6–115.0) and 89.1 (87.6–102.0) mmHg in the SV, CMV, ARM1 and ARM2 groups, respectively. PaO2 decreased at 30 minutes after extubation in the CMV, ARM1 and ARM2 groups (p Conclusions and clinical relevance Intraoperative ARMs, followed by PEEPmaxCrs+2, did not improve early postoperative arterial oxygenation compared with SV or CMV alone in healthy anaesthetized dogs. Therefore, this ventilatory strategy might not be clinically advantageous for improving postoperative arterial oxygenation in healthy dogs undergoing surgery when positioned in dorsal recumbency.

COVID-19 infection primarily causes severe pneumonia complicated by acute respiratory distress syndrome and multiorgan failure requiring a ventilator support. We present a case of a 55-year-old male, admitted with COVID-19. He was obese but had no other medical conditions. His blood pressure was measured by his general physician on several occasions in the past, all values being normal (

Purpose Fluid boluses (FB) are often used in post-cardiac arrest (CA) patients with haemodynamic instability. Although FB may improve cardiac output (CO) and mean arterial pressure (MAP), FB may also increase central venous pressure (CVP), reduce arterial PaO2, dilute haemoglobin and cause interstitial oedema. The aim of the present study was to investigate the net effect of FB administration on cerebral tissue oxygenation saturation (SctO2) in post-CA patients. Methods Pre-planned sub-study of the Neuroprotect post-CA trial (NCT02541591). Patients with anticipated fluid responsiveness based on stroke volume variation (SVV) or passive leg raising test were administered a FB of 500 ml plasma-lyte A (Baxter Healthcare) and underwent pre- and post-FB assessments of stroke volume, CO, MAP, CVP, haemoglobin, PaO2 and SctO2. Results 52 patients (mean age 64 ± 12 years, 75% male) received a total of 115 FB. Although administration of a FB resulted in a significant increase of stroke volume (63 ± 22 vs 67 ± 23 mL, p = 0.001), CO (4,2 ± 1,6 vs 4,4 ± 1,7 L/min, p = 0.001) and MAP (74,8 ± 13,2 vs 79,2 ± 12,9 mmHg, p = 0.004), it did not improve SctO2 (68.54 ± 6.99 vs 68.70 ± 6.80%, p = 0.49). Fluid bolus administration also resulted in a significant increase of CVP (10,0 ± 4,5 vs 10,7 ± 4,9 mmHg, p = 0.02), but did not affect PaO2 (99 ± 31 vs 94 ± 31 mmHg, p = 0.15) or haemoglobin concentrations (12,9 ± 2,1 vs 12,8 ± 2,2 g/dL, p = 0.10). In a multivariate model, FB-induced changes in CO (beta 0,77; p = 0.004) and in CVP (beta −0,23; p = 0.02) but not in MAP (beta 0,02; p = 0.18) predicted post-FB ΔSctO2. Conclusions Despite improvements in CO and MAP, FB administration did not improve SctO2 in post-cardiac arrest patients.

Aims Skeletal muscle dysfunction is a systemic consequence of heart failure (HF) that correlates with functional capacity. However, the impairment within the skeletal muscle is not well established. We investigated the effect of exercise training on peripheral muscular performance and oxygenation in HF patients. Methods and results HF patients with ejection fraction ≤40% were randomized 2:1 to exercise training or control for 12 weeks. Muscle tissue oxygen was measured noninvasively by near-infrared spectroscopy (NIRS) during rest and a symptom-limited cardiopulmonary exercise test (CPET) before and after intervention. Measurements included skeletal muscle oxygenated hemoglobin concentration, deoxygenated hemoglobin concentration, total hemoglobin concentration, VO2 peak, VE/VCO2 slope, and heart rate. Muscle sympathetic nerve activity by microneurography, and muscle blood flow by plethysmography were also assessed at rest pre and post 12 weeks. Twenty-four participants (47.5 ± 7.4 years, 58% men, 75% no ischemic) were allocated to exercise training (ET, n = 16) or control (CG, n = 8). At baseline, no differences between groups were found. Exercise improved VO2 peak, slope VE/VCO2, and heart rate. After the intervention, significant improvements at rest were seen in the ET group in muscle sympathetic nerve activity and muscle blood flow. Concomitantly, a significant decreased in Oxy-Hb (from 29.4 ± 20.4 to 15.7 ± 9.0 μmol, p = 0.01), Deoxi-Hb (from 16.3 ± 8.2 to 12.2 ± 6.0 μmol, p = 0.003) and HbT (from 45.7 ± 27.6 to 27.7 ± 13.4 μmol, p = 0.008) was detected at peak exercise after training. No changes were observed in the control group. Conclusion Exercise training improves skeletal muscle function and functional capacity in HF patients with reduced ejection fraction. This improvement was associated with increased oxygenation of the peripheral muscles, increased muscle blood flow, and decreased sympathetic nerve activity.

Objective: To determine the effect of fraction of inspired oxygen (FIO2) on intrapulmonary shunt fraction as measured by F-shunt in ponies during isoflurane anaesthesia. Study design: Prospective, randomized clinical study. Animals: A group of 23 adult Shetland ponies undergoing a total of 32 anaesthetic procedures. Methods: Ponies were premedicated intravenously (IV) with detomidine (0.01 mg kg–1) and either morphine (0.1 mg kg–1) or butorphanol (0.02 mg kg–1). Anaesthesia was induced with ketamine (2.2 mg kg–1) and midazolam (0.07 mg kg–1) administered IV. Ponies were randomly allocated to maintenance of anaesthesia with isoflurane in oxygen (group TH; FIO2 = 0.95) or a mixture of oxygen and medical air (group TL; FIO2 = 0.65); all ponies were given a constant rate of infusion of detomidine. Animals were mechanically ventilated to maintain PaCO2 between 40 and 50 mmHg. Arterial blood gas analysis was performed every 30 minutes. The F-shunt equation was calculated for each time point T0, T30, T60 and T90. Data were analysed using linear mixed model analysis and presented as mean ± standard deviation (p < 0.05). Results: PaO2 was greater in group TH than in group TL (TH: 406 ± 90, 438 ± 83, 441 ± 69 and 464 ± 53 mmHg versus TL: 202 ± 90, 186 ± 84, 172 ± 85 and 191 ± 98 mmHg at T0, T30, T60 and T90, respectively; p < 0.0001). In TH, F-shunt was < TL. Significant differences were found at T60 (TH: 13.2% ± 4.3 versus TL: 19.4% ± 8.3; p = 0.016) and T90 (TH: 11.7% ± 3.5 versus TL: 18.6% ± 9.5; p = 0.036). Conclusions and clinical relevance: Our findings do not support a beneficial effect of using a reduced FIO2 to improve oxygenation in anaesthetized and mechanically ventilated Shetland ponies.

BackgroundIncreasing evidence recognizes the harm of excess oxygen to lungs, eyes, and brain of preterm infants, but not yet to the intestine. We assessed changes in splanchnic oxygenation during reoxygenation with 21% compared to 100% O-2 in a newborn piglet model of perinatal asphyxia.MethodsWe randomized 25 piglets to control or intervention. Intervention groups underwent global hypoxia until acidosis and hypotension occurred. Piglets were reoxygenated for 30 min with 21% or 100% O-2 and observed for 9 h. We continuously measured regional splanchnic oxygen saturation (r(s)SO(2)) using near-infrared spectroscopy (NIRS). We calculated mean r(s)SO(2) and r(s)CoVar (as SD/mean). We measured PaO2 and SaO(2), sampled from the right carotid artery. ResultsReoxygenation after global hypoxia restored r(s)SO(2). Reoxygenation with 100% O-2 increased r(s)SO(2) to values significantly higher than baseline. In intervention groups, r(s)CoVar decreased during observation compared to baseline. We found a correlation between r(s)SO(2) and PaO2 (r = 0.420, P < 0.001) and between r(s)SO(2) and SaO(2) (r = 0.648, P < 0.001) in pooled data from the entire experiment.ConclusionReoxygenation after global hypoxia improves splanchnic oxygenation, but is associated with reduced variability of r(s)SO(2). Reoxygenation with 100% O-2 exposes the intestine to hyperoxia. Splanchnic NIRS is able to detect intestinal hypoxia and hyperoxia.ImpactSplanchnic oxygenation improves during reoxygenation after global hypoxia, though reoxygenation with 100% O2 exposes the intestine to hyperoxia. Decreased variability of splanchnic oxygenation several hours after hypoxia and reoxygenation seems to be independent of the resuscitation strategy, and may indicate intestinal injury. Splanchnic NIRS monitoring was able to detect intestinal hypoxia and exposure to hyperoxia, as evidenced by a strong correlation between splanchnic oxygenation and arterial oxygen content.

The aim of the work is to find out the effectiveness and duration of the breathing exercises with PEEP action on the cardiovascular system state in older patients with COPD. Materials and methods. A total of 35 patients with COPD aged 60–74 years were examined. All the patients were divided into two groups: the main group (18 people) who received breathing exercises with PEEP, and the control group (17 people) who received simulated exercises. The cardiovascular system state was assessed. The examinations were performed in the initial state (before training), immediately after, one month later, and three months after the training course. Results. The cardiovascular system state improved as a result of breathing exercises with PEEP in older patients with COPD. At the same time, the duration of the breathing exercises with PEEP action was short; the effect of their use was not preserved in a month. Relationships between shifts in SpO2 and cardiac output, as well as between shifts in SpO2 and peripheral vascular resistance immediately after the use of breathing exercises with PEEP in older patients with COPD have been established. A more significant and prolonged effect of breathing exercises with PEEP on the cardiovascular system functional state was observed in older COPD patients with more severe symptoms of the disease. Conclusions. The increase in cardiovascular performance was influenced by breathing exercises with PEEP in older COPD patients due to the improved lung oxygenation capacity. The effect of breathing exercises with PEEP remained within a month after the training course and was more stable and longer in patients with severe clinical symptoms. Older COPD patients are advised to repeat the courses of breathing exercises with PEEP every month.

OBJECTIVE To evaluate inhaled nitric oxide (iNO) in preterm (PT) vs term/near-term (TNT) neonates with hypoxic respiratory failure (HRF) and pulmonary hypertension (PH) in an observational registry (PaTTerN). STUDY DESIGN Non-inferiority study comparing PT neonates of GA ≥ 27 to

Modification of amino acids is an important strategy in organic and bioorganic chemistry. In contrast to common side-chain functionalization, backbone modification is much less explored. Especially glycine units seem to be attractive and versatile since a wide range of functionality can be potentially introduced. We report here oxidative modification of glycinates that are stable and enable further functionalization. Selective glycinate enolate oxidation by TEMPO or a FeCp2PF6/TEMPO reagent combination provides stable alkoxyamines in good to excellent yields. The methodology is expanded to glycine-containing dipeptides demonstrating selective oxygenation at the glycine unit. The orthogonal reactivity potential of oxygenated glycines for transformation to other amino acid derivatives is explored.

To evaluate the state of external respiration system, breath-holding tests are usually used. However, there are few studies of the peculiarities of the gas exchange in breath-holding with previous hyperventilation. The purpose of the study was to analyze the dynamics of changes in the PetCO2 level and arterial blood oxygenation during breath-holding tests with and without previous hyperventilation in healthy young men. Materials and methods. The СО2 level was recorded in the side stream on the Datex Normocap capnograph (Datex, Finland). This value was recorded for 5 minutes at rest, 5 minutes after half-breath hold, for 5 minutes of regulated breathing with a frequency of 30 cycles per minute, 5 minutes after half-breath hold. The capnogram, atmospheric pressure level and humidity were used to assess the level of СО2 at the end of exhalation (PetCO2), respiratory rate, the ratio of inspiratory duration to expiratory duration (Rie). Statistical processing of the results was performed by parametric methods. According to the method of sigmoid deviation, three groups of individuals were distinguished by the PetCO2 level: I – PetCO2 < 32.7 mmHg, II – PetCO2 – 32.7-36.2 mmHg, III – PetCO2 > 36.2 mmHg. Results and discussion. Breath-holding during the test after hyperventilation was significantly greater than in the first attempt (62.99±3.31 s and 33.78±2.24 s, p

The effects of fish size and nitrite level on metabolic rate and growth were investigated in the obligate air-breathing snakehead Channa striata, which is an important aquaculture species in Vietnam. Channa striata displayed respiratory size dependence, whereby the standard metabolic rate (SMR) and routine metabolic rate (RMR) decreased progressively in an exponential manner as fish size increased from 50 to 200 g. A mildly elevated nitrite level of 5% of the LC50 96 h (12 mg NO2−/L or safe concentration) induced significant increases in Channa striata SMR and RMR, which were almost double that of the control at the same size. At mild elevation, nitrite caused no significant effect on fish growth and survival during 3 months of rearing. However, both growth and survival rates of fish reared at severely elevated nitrite levels were significantly lower than those of the control; in particular, survival rates were under 50%. While changes in size reduced SMR and RMR, the percentage of air oxygen partitioning remained unchanged. Channa striata upregulation of SMR and RMR and air-breathing regulation were not significantly proven in this study. In summary, maintaining water environments at levels lower than 12 mg NO2−/L with ample oxygenation will not affect the growth and survival rate of snakeheads.

The accumulation of oxygen is one of the most important characteristics that distinguish Earth from other planets in the solar system, which is also considered to be the key factor influencing the birth and evolution of complex life forms. The oxygenation process of the Earth surface has long been viewed to be episodic with two critical intervals occurring in the early Paleoproterozoic (2.45–2.10 Ga) and the late Neoproterozoic (0.80–0.54 Ga), with a 1.3-billion-year-long low oxygen period in between. Recently, increasing independent works carried out by different scientific teams in the Yanliao Basin, North China are demonstrating that the atmospheric oxygen concentrations had reached >4% PAL (present atmospheric levels) at least during 1.59–1.56, 1.44–1.43, and 1.40–1.36 Ga. These estimated values are higher than the previously recommended values of

PURPOSE OF REVIEW: Noninvasive respiratory support has been widely applied during the COVID-19 pandemic. We provide a narrative review on the benefits and possible harms of noninvasive respiratory support for COVID-19 respiratory failure. RECENT FINDINGS: Maintenance of spontaneous breathing by means of noninvasive respiratory support in hypoxemic patients with vigorous spontaneous effort carries the risk of patient self-induced lung injury: the benefit of averting intubation in successful patients should be balanced with the harms of a worse outcome in patients who are intubated after failing a trial of noninvasive support.The risk of noninvasive treatment failure is greater in patients with the most severe oxygenation impairment (PaO2/FiO2 

The Great Oxidation Event (GOE), among Earth's most transformative events, marked the sustained presence of oxygen above 10−5 times the present atmospheric level. Estimates of the onset of the GOE span 2501–2225 Ma and are based primarily on the loss of mass-independent fractionation of sulfur isotopes (MIF-S) in pyrite. To better constrain the timing of the GOE, we apply probabilistic techniques to estimate the confidence intervals of four proxies: MIF-S, redox-sensitive detrital minerals, “red beds,” and I/(Ca + Mg). These GOE proxies are drawn from a highly fragmentary geologic record, and consequently, estimates of the 95% confidence intervals span tens to hundreds of millions of years—orders of magnitude larger than suggested by radiometric constraints on individual successions. Confidence interval results suggest that red beds and nonzero I/(Ca + Mg) values may have appeared earlier than 2480 Ma and 2460 Ma, respectively, whereas redox-sensitive detrital minerals and MIF-S may have disappeared after 2210 Ma and 2190 Ma, respectively. These data suggest a delay of potentially >300 m.y. between initial and permanent oxygenation of the atmosphere and a delay of tens of millions of years between onset of the Lomagundi-Jatuli carbon isotope excursion and permanent oxygenation of the atmosphere.

Background. Septic patients often require mechanical ventilation due to respiratory dysfunction, and effective ventilatory strategies can improve survival. The effects of the combination of permissive hypoxia and hyperoxia avoidance for managing mechanically ventilated patients are unknown. This study examines these effects on outcomes in mechanically ventilated septic patients. Methods. In a retrospective before-and-after study, we examined adult septic patients (aged ≥18 years) requiring mechanical ventilation at a university hospital. On April 1, 2017, our mechanical ventilation policy changed from a conventional oxygenation target (SpO2: ≥96%) to more conservative targets with permissive hypoxia (SpO2: 88-92% or PaO2: 60 mmHg) and hyperoxia avoidance (reduced oxygenation for Pa O 2 > 110 mmHg ). Patients were divided into a prechange group (April 2015 to March 2017; n = 83 ) and a postchange group (April 2017 to March 2019; n = 130 ). Data were extracted from clinical records and insurance claims. Using a multiple logistic regression model, we examined the association of the postchange group (permissive hypoxia and hyperoxia avoidance) with intensive care unit (ICU) mortality after adjusting for variables such as Sequential Organ Failure Assessment (SOFA) score and PaO2/FiO2 ratios. Results. The postchange group did not have significantly lower adjusted ICU mortality (0.67, 0.33-1.43; P = 0.31 ) relative to the prechange group. However, there were significant intergroup differences in mechanical ventilation duration (prechange: 11.0 days, postchange: 7.0 days; P = 0.01 ) and ICU stay (prechange: 11.0 days, postchange: 9.0 days; P = 0.02 ). Conclusions. Permissive hypoxia and hyperoxia avoidance had no significant association with reduced ICU mortality in mechanically ventilated septic patients. However, this approach was significantly associated with shorter mechanical ventilation duration and ICU stay, which can improve patient turnover and ventilator access.

Pacientes internados por causa da Covid-19 foram tratados com eletroterapia e obtiveram bons resultados em relação subsequente recuperação. Dois hospitais do Brasil utilizaram as correntes elétricas na recuperação de pacientes que ficaram entubados por longos períodos na UTI. O aparelho emissor de terapia infravermelho longo ativa trilhões de células por minuto, eliminando ácido lático e toxinas e promovendo uma melhoria na circulação de oxigênio e o aumento do sistema imunológico por oxigenação celular.

Preoxygenation is a widespread technique before induction into anesthesia and tracheal intubation, designed to increase the body oxygen stores and, thereby, to delay the onset of arterial hemoglobin desaturation during apnea. The indicators of preoxygenation effectiveness are: an increase in the fraction of alveolar oxygen, an increase in arterial oxygen tension and a decrease in the fraction of alveolar nitrogen. The end point of maximum preoxygenation is the end expiratory oxygen concentration of 90 % or end expiratory nitrogen concentration of 5 %. Two techniques are used for preoxygenation: tidal volume breathing and deep breathing. There are various techniques for improving the effect of preoxygenation. They include head lifting, apneic diffusion oxygenation, the use of continuous positive airway pressure/positive end expiratory pressure, bilevel positive airway pressure and transnasal humidified rapid insufflation ventilator exchange. High risk preoxygenation includes such patients as pregnant women, obese patients, children, the elderly, patients with concomitant pulmonary disea­ses, patients at high altitude. Potential risks of preoxygenation include a delayed esophageal intubation, absorption atelectasis, the production of active oxygen particles and undesirable hemodynamic effects. Hemodynamic effects and accumulation of active oxygen particles during preoxygenation are insignificant. Absorptive atelectasis is a consequence of preoxygenation. To reduce the risk of absorption atelectasis during preoxygenation, two approaches have been proposed: a moderate reduction in the oxygen fraction to 0.8 and the use of recruitment maneuvers such as constant positive airway pressure, positive end expiratory pressure and/or vital capacity maneuver. Although the slight pressure of the oxygen fraction reduces the risk of atelectasis, this is due to the reduction of the oxygen reserve. The technique of preoxygenation should be used correctly, with monitoring of oxygen concentration at the end of expiration. An anesthetist should be familiarized with the various methods of conducting preoxygenation, choosing the most suitable., Преоксигенация является широко распространенным приемом перед индукцией в анестезию и интубацией трахеи, предназначенным для увеличения запасов кислорода в организме и, таким образом, замедления начала десатурации гемоглобина во время апноэ. Показателями эффективности преоксигенации являются увеличение фракции альвеолярного кислорода, увеличение напряжения кислорода в артериальной крови и снижение фракции альвеолярного азота. Конечная точка максимальной преоксигенации — концентрация кислорода в конце выдоха 90 % или концентрация азота в конце выдоха 5 %. Для проведения преоксигенации используются две техники: по дыхательному объему и путем глубоких вдохов. Существуют различные методики для улучшения эффекта преоксигенации. Они включают поднятие головы, апнойную диффузную оксигенацию, использование постоянного положительного давления/положительного давления конца выдоха, двухуровневое положительное давление в дыхательных путях и трансназальную увлажненную быструю инсуффляцию. Преоксигенация с высоким риском включает таких пациентов, как беременные женщины, пациенты, страдающие ожирением, дети, лица пожилого возраста, пациенты с сопутствующими легочными заболеваниями, пациенты на большой высоте. Потенциальные риски преоксигенации включают отсроченное определение пищеводной интубации, абсорбционный ателектаз, продукцию частиц активного кислорода и нежелательные гемодинамические эффекты. Так как преоксигенация по времени не продолжительна, гемодинамические эффекты и накопление частиц активного кислорода незначительны. Абсорбционный ателектаз является следствием преоксигенации. Для снижения риска возникновения абсорбционного ателектаза во время преоксигенации предложено два подхода: умеренное снижение фракции кислорода до 0,8 и использование рекрутмент-маневров, таких как постоянное положительное давление, положительное давление конца выдоха и/или маневры с жизненной емкостью легких. Хотя незначительное давление фракции кислорода уменьшает риск ателектазирования, это происходит за счет снижения кислородного резерва. Техника преоксигенации должна использоваться правильно, с мониторированием концентрации кислорода в конце выдоха. Анестезиолог должен быть ознакомлен с различными методиками проведения преоксигенации, выбирая наиболее подходящую., Преоксигенація є значно поширеним прийомом перед індукцією в анестезію і інтубацією трахеї, призначеним для збільшення запасів кисню в організмі і, таким чином, уповільнення початку десатурації гемоглобіну під час апное. Показниками ефективності преоксигенації є збільшення фракції альвеолярного кисню, збільшення напруження кисню в артеріальній крові і зниження фракції альвеолярного азоту. Кінцева точка максимальної преоксигенації — концентрація кисню в кінці видиху 90 % або концентрація азоту в кінці видиху 5 %. Для проведення преоксигенації використовуються дві техніки: за дихальним об’ємом і шляхом глибоких вдихів. Існують різні методики для поліпшення ефекту преоксигенації. Вони включають підняття голови, апнойну дифузну оксигенацію, використання постійного позитивного тиску/позитивного тиску кінця видоху, дворівневий позитивний тиск у дихальних шляхах і трансназальну зволожену швидку інсуфляцію. Преоксигенація з високим ризиком включає таких пацієнтів, як вагітні жінки, пацієнтів, які страждають від ожиріння, дітей, осіб похилого віку, пацієнтів із супутніми легеневими захворюваннями, пацієнтів на великій висоті. Потенційні ризики преоксигенації включають відстрочене визначення стравохідної інтубації, абсорбційний ателектаз, продукцію часток активного кисню і небажані гемодинамічні ефекти. Через те що преоксигенація за часом нетривала, гемодинамічні ефекти і накопичення часток активного кисню є незначними. Абсорбційний ателектаз є наслідком преоксигенації. Для зниження ризику виникнення абсорбційного ателектазу під час преоксигенації запропоновано два підходи: помірне зниження фракції кисню до 0,8 і використання рекрутмент-маневрів, таких як постійний позитивний тиск, позитивний тиск кінця видиху і/або маневри з життєвою ємністю легень. Хоча незначний тиск фракції кисню зменшує ризик ателектазування, це відбувається за рахунок зниження кисневого резерву. Техніка преоксигенації повинна використовуватися правильно, з моніторуванням концентрації кисню в кінці видиху. Анестезіолог повинен бути ознайомлений з різними методиками проведення преоксигенації, вибираючи найбільш прийнятну.

The article analyzes the role of microcirculatory disorders in the pathogenesis of inflammatory complications (peri-implantitis) in patients with orthopedic constructions on dental implants and substantiates the possibility of a complex course application of low-intensity infrared laser therapy and low-frequency electrostatic therapy. It was shown that the initial state of patients with peri-implantitis is characterized by significantly low values of the level of general perfusion and its intensity, as well as the predominance of shunt mechanisms that reduce the values of the nutritive link of blood flow. The cause of the revealed disorders is the low level of functioning of the vasodilation mechanisms, caused by inflammatory and destructive processes in the peri-implant tissues. The use of a complex of physiotherapeutic exposure was characterized by a more pronounced corrective effect on the parameters of microcirculation and oxidative metabolism in comparison with standard dental treatment. The observed dynamics of microcirculatory systems of tissues of the peri-implant zone under the conditions of the complex influence of physiotherapeutic factors is aimed at the formation of adaptive reactions of local hemodynamics to the local needs of soft and bone tissues experiencing an inflammatory process around the implant, as well as strengthening the mechanisms of long-term adaptation of trophic relations in tissue peri-implant microregions. Taking into account the pathogenetic significance of microhemodynamic disorders in the formation of clinical manifestations of peri-implantitis, the revealed activating effect of the technology of the combined use of a laser and low-frequency electrostatic therapy serves as an objective proof of its therapeutic efficacy.

Objective Because of the abundance of complications associated with peri-intubation hypoxia, maintaining adequate oxygen saturation during endotracheal intubation (ETI) is of great concern. In addition to standard preoxygenation techniques, apneic oxygenation (AO), the continuous flow of passive oxygenation, is a potential tool that can be used to eliminate hypoxia during ETI. Although scarcely studied in the pediatric population, AO has proven effective in reducing the incidence of hypoxia in adult patients with minimal side effects. The objective of this study is to evaluate the use of apneic oxygenation in pediatric patients and to determine its efficacy in preventing or delaying oxygen desaturation during the apneic period of ETI. Methods This literature review examines 4 studies that evaluate the practice of AO in pediatric patients. A total of 712 patients across 3 randomized control trials and 1 observational study were assigned to either a control group that did not receive any form of AO, a group that did not receive 100% fraction of inspired oxygen (FiO2), or an intervention group where various methods of AO were delivered. Results Each AO method that provided 100% FiO2 saw a significantly longer time until initial desaturation when compared with those that did not receive any form of AO or those not receiving 100% FiO2. Conclusions The findings in this study confirm that the practice of AO is not only efficacious in increasing the time until initial desaturation but also reduces the overall incidence of hypoxia during laryngoscopy in children.

Acute respiratory failure (ARF) in immunocompromised patients remains challenging to treat. A large number of case require admission to intensive care unit (ICU) where mortality remains high. Oxygenation without intubation is important in this setting. This review summarizes recent studies assessing oxygenation devices for immunocompromised patients. Previous studies showed that non-invasive ventilation (NIV) has been associated with lower intubation and mortality rates. Indeed, in recent years, the outcomes of immunocompromised patients admitted to the ICU have improved. In the most recent randomized controlled trials, including immunocompromised patients admitted to the ICU with ARF, neither NIV nor high-flow nasal oxygen (HFNO) could reduce the mortality rate. In this setting, other strategies need to be tested to decrease the mortality rate. Early admission strategy and avoiding late failure of oxygenation strategy have been assessed in retrospective studies. However, objective criteria are still lacking to clearly discriminate time to admission or time to intubation. Also, diagnosis strategy may have an impact on intubation or mortality rates. On the other hand, lack of diagnosis has been associated with a higher mortality rate. In conclusion, improving outcomes in immunocompromised patients with ARF may include strategies other than the oxygenation strategy alone. This review discusses other unresolved questions to decrease mortality after ICU admission in such patients.

A 54-year-old man with hereditary hemorrhagic telangiectasia and severe hypoxemia was referred for lung transplantation. Embolization had not been performed because of numerous bilateral small pulmonary arteriovenous malformations. Although he appeared to be qualified for lung transplantation, we instead performed bilateral thoracoscopic multiple wide wedge resections because of his age, lifestyle as a farmer, and relatively clustered distribution of arteriovenous malformations. Intermittent bilateral ventilation was needed because of poor oxygenation in the early stages of the operation, but his oxygenation improved as the resection progressed. His postoperative oxygenation improved significantly, and lung transplantation was avoided.