Intermittent hypoxia training effectively protects against cognitive decline caused by acute hypoxia exposure.

Intermittent hypoxia training (IHT) is a promising approach that has been used to induce acclimatization to hypoxia and subsequently lower the risk of developing acute mountain sickness (AMS). However, the effects of IHT on cognitive and cerebrovascular function after acute hypoxia exposure have not been characterized. In the present study, we first confirmed that the simplified IHT paradigm was effective at relieving AMS at 4300 m. Second, we found that IHT improved participants' cognitive and neural alterations when they were exposed to hypoxia. Specifically, impaired working memory performance, decreased conflict control function, impaired cognitive control, and aggravated mental fatigue induced by acute hypoxia exposure were significantly alleviated in the IHT group. Furthermore, a reversal of brain swelling induced by acute hypoxia exposure was visualized in the IHT group using magnetic resonance imaging. An increase in cerebral blood flow (CBF) was observed in multiple brain regions of the IHT group after hypoxia exposure as compared with the control group. Based on these findings, the simplified IHT paradigm might facilitate hypoxia acclimatization, alleviate AMS symptoms, and increase CBF in multiple brain regions, thus ameliorating brain swelling and cognitive dysfunction.

Higher dose corticosteroids in patients admitted to hospital with COVID-19 who are hypoxic but not requiring ventilatory support (RECOVERY): a randomised, controlled, open-label, platform trial.

BACKGROUND: Low-dose corticosteroids have been shown to reduce mortality for patients with COVID-19 requiring oxygen or ventilatory support (non-invasive mechanical ventilation, invasive mechanical ventilation, or extracorporeal membrane oxygenation). We evaluated the use of a higher dose of corticosteroids in this patient group. METHODS: This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing multiple possible treatments in patients hospitalised for COVID-19. Eligible and consenting adult patients with clinical evidence of hypoxia (ie, receiving oxygen or with oxygen saturation <92% on room air) were randomly allocated (1:1) to either usual care with higher dose corticosteroids (dexamethasone 20 mg once daily for 5 days followed by 10 mg dexamethasone once daily for 5 days or until discharge if sooner) or usual standard of care alone (which included dexamethasone 6 mg once daily for 10 days or until discharge if sooner). The primary outcome was 28-day mortality among all randomised participants. On May 11, 2022, the independent data monitoring committee recommended stopping recruitment of patients receiving no oxygen or simple oxygen only due to safety concerns. We report the results for these participants only. Recruitment of patients receiving ventilatory support is ongoing. The RECOVERY trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). FINDINGS: Between May 25, 2021, and May 13, 2022, 1272 patients with COVID-19 and hypoxia receiving no oxygen (eight [1%]) or simple oxygen only (1264 [99%]) were randomly allocated to receive usual care plus higher dose corticosteroids (659 patients) versus usual care alone (613 patients, of whom 87% received low-dose corticosteroids during the follow-up period). Of those randomly assigned, 745 (59%) were in Asia, 512 (40%) in the UK, and 15 (1%) in Africa. 248 (19%) had diabetes and 769 (60%) were male. Overall, 123 (19%) of 659 patients allocated to higher dose corticosteroids versus 75 (12%) of 613 patients allocated to usual care died within 28 days (rate ratio 1·59 [95% CI 1·20-2·10]; p=0·0012). There was also an excess of pneumonia reported to be due to non-COVID infection (64 cases [10%] vs 37 cases [6%]; absolute difference 3·7% [95% CI 0·7-6·6]) and an increase in hyperglycaemia requiring increased insulin dose (142 [22%] vs 87 [14%]; absolute difference 7·4% [95% CI 3·2-11·5]). INTERPRETATION: In patients hospitalised for COVID-19 with clinical hypoxia who required either no oxygen or simple oxygen only, higher dose corticosteroids significantly increased the risk of death compared with usual care, which included low-dose corticosteroids. The RECOVERY trial continues to assess the effects of higher dose corticosteroids in patients hospitalised with COVID-19 who require non-invasive ventilation, invasive mechanical ventilation, or extracorporeal membrane oxygenation. FUNDING: UK Research and Innovation (Medical Research Council), National Institute of Health and Care Research, and Wellcome Trust.

Lung ultrasound-guided best positive end-expiratory pressure in neonatal anesthesia: a proposed randomized, controlled study.

BACKGROUND: Atelectasis is a common complication in neonatal anesthesia. Lung ultrasound (LUS) can be used intraoperatively to evaluate and recognize atelectatic lung areas. Hypotheses for the study are: (1) The use of LUS to guide choice of best positive end-expiratory pressure (PEEP) can lead to reduction of FiO2 to achieve same saturations of oxygen (SpO2). (2) In a less de-recruited lung, there will be less postoperative pulmonary complications. (3) Static respiratory system compliance could be different. (4) Hemodynamic parameters and amount of fluids infused or need for vasopressors intraoperatively could be different. METHODS: We propose a randomized controlled trial that compares standard PEEP settings with LUS-guided PEEP choice in patients under 2 months of age undergoing general anesthesia. RESULTS: The primary aim is to determine whether LUS-guided PEEP choice in neonatal anesthesia, compared to standard PEEP choice, can lead to reduction of FiO2 applied to the ventilatory setting in order to maintain same SpO2s. Secondary aims are to determine whether patients treated with LUS-guided PEEP will develop less postoperative pulmonary complications, will have a significant difference in hemodynamic parameters and amount of fluids or vasopressors infused, and in static respiratory system compliance. CONCLUSIONS: We expect a significant reduction of FiO2 in LUS-guided ventilation. IMPACT: Lung atelectasis is extremely common in neonatal anesthesia, because of the physiology of the neonatal lung and chest wall and leads to hypoxemia, being a lung area with a perfusion/ventilation mismatch. Raising inspired fraction of oxygen can overcome temporarily hypoxemia but oxygen is a toxic compound for newborns. Lung ultrasound (LUS) can detect atelectasis at bedside and be used to optimize ventilator settings including choice of positive end-expiratory pressure (PEEP). This randomized controlled trial (RCT) aims at demonstrating that LUS-guided choice of best PEEP during neonatal anesthesia can lead to reduction of inspired fractions of oxygen to keep same peripheral saturations SpO2.

Supraglottic Jet Oxygenation and Ventilation to Minimize Hypoxia in Patients Receiving Flexible Bronchoscopy Under Deep Sedation: A 3-Arm Randomized Controlled Trial.

BACKGROUND: Hypoxia often occurs due to shared airway and anesthetic sedation-induced hypoventilation in patients receiving flexible bronchoscopy (FB) under deep sedation. Previous evidence has shown that supraglottic jet oxygenation and ventilation (SJOV) via Wei nasal jet tube (WNJ) reduces the incidence of hypoxia during FB. This study aimed to investigate the extent to which SJOV via WNJ could decrease the incidence of hypoxia in patients under deep sedation as compared to oxygen supplementation via WNJ alone or nasal catheter (NC) for oxygen supplementation during FB. METHODS: This was a single-center 3-arm randomized controlled trial (RCT). Adult patients scheduled to undergo FB were randomly assigned to 3 groups: NC (oxygen supplementation via NC), low-pressure low-flow (LPLF) (low-pressure oxygen supplementation via WNJ alone), or SJOV (high-pressure oxygen supplementation via WNJ). The primary outcome was hypoxia (defined as peripheral saturation of oxygen [Sp o2 ] <90% lasting more than 5 seconds) during FB. Secondary outcomes included subclinical respiratory depression or severe hypoxia, and rescue interventions specifically performed for hypoxia treatment. Other evaluated outcomes were sore throat, xerostomia, nasal bleeding, and SJOV-related barotraumatic events. RESULTS: One hundred and thirty-two randomized patients were included in 3 interventions (n = 44 in each), and all were included in the final analysis under intention to treat. Hypoxia occurred in 4 of 44 patients (9.1%) allocated to SJOV, compared to 38 of 44 patients (86%) allocated to NC, with a relative risk (RR) for hypoxia, 0.11; 98% confidence interval (CI), 0.02-0.51; P < .001; or to 27 of 44 patients (61%) allocated to LPLF, with RR for hypoxia, 0.15; 95% CI, 0.04-0.61; P < .001, respectively. The percentage of subclinical respiratory depression was also significantly diminished in patients with SJOV (39%) compared with patients with NC (100%) or patients with LPLF (96%), both P < .001. In SJOV, no severe hypoxia event occurred. More remedial interventions for hypoxia were needed in the patients with NC. Higher risk of xerostomia was observed in patients with SJOV. No severe adverse event was observed throughout the study. CONCLUSIONS: SJOV via WNJ effectively reduces the incidence of hypoxia during FB under deep sedation.

High-flow nasal cannula oxygen reduced hypoxemia in patients undergoing gastroscopy under general anesthesia at ultra-high altitude: a randomized controlled trial.

BACKGROUND: Hypoxemia can occur in people at ultra-high altitude (above 3500 m) even at rest, and patients undergoing gastroscopy under general anesthesia have higher risk of hypoxemia. Supplementary oxygen via standard nasal cannula (SNC) is the standard of care for most patients who undergo gastroscopy under general anesthesia, which provides oxygen flow up to 15 L/min. High-flow nasal cannula (HFNC) could deliver oxygen at a rate up to 60 L/min, which is recommended by the American Society of Anesthesiologists Practice Guidelines. We speculated that the benefit with HFNC is more prominent in high-altitude areas, and aimed to compare the incidence of hypoxemia during gastroscopy under general anesthesia at ultra-high altitude with oxygen supply via either HFNC or SNC. METHODS: The trial was registered at at Chinese Clinical Trial Registry (ChiCTR2100045513; date of registration on 18/04/2021). Adult patients undergoing gastroscopy with anesthesia (estimated duration of anesthesia at ≥ 15 min) were randomized at a 1:1 ratio to receive HFNC oxygen or SNC oxygen. The primary outcome was hypoxemia (SpO2 < 90% for any duration). Secondary outcomes included severe hypoxemia (SpO2 < 75% for any duration or SpO2 < 90% but ≥ 75% for ≥ 60 s) and hypotension, as defined by reduction of mean arterial blood pressure by ≥ 25% from the baseline. RESULTS: A total of 262 patients were enrolled: 129 in the HFNC group and 133 in the SNC group. All patients received the designated intervention. Student's t-test, Mann-Whitney U test and χ2 test were employed in the study. The rate of hypoxemia was 9.3% (12/129) in the HFNC group versus 36.8% (49/133) in the SNC group [risk ratio (95% confidence interval): 0.25(0.14-0.45); P < 0.001). The HFNC group also had lower rate of severe hypoxemia [0.0% (0/129) versus 11.3% (15/133); risk ratio (95% confidence interval): 0.03(0.00-0.55); P < 0.001, respectively]. The rate of hypotension did not differ between the 2 groups [22.5% (29/129) in HFNC group versus 21.1% (28/133) in SNC group; risk ratio (95% confidence interval): 1.07(0.67-1.69) ; P = 0.779]. CONCLUSION: HFNC oxygen reduced the incidence of hypoxemia during anesthesia in adult patients undergoing gastroscopy at ultra-high altitude.

Supraglottic jet oxygenation and ventilation improves oxygenation during endoscopic retrograde cholangiopancreatography: a randomized controlled clinical trial.

PURPOSE: Hypoxia is one of the most frequent adverse events under deep sedation in the semiprone position. We hypothesized that supraglottic jet oxygenation and ventilation (SJOV) via Wei nasal jet tube (WNJ) can reduce the incidence of hypoxia in patients under deep sedation during endoscopic retrograde cholangiopancreatography (ERCP). METHODS: A total of 171 patients were divided into three groups: N group, supplementary oxygen via a nasopharyngeal airway (4-6 L/min); W group, supplementary oxygen via WNJ (4-6 L/min); WS group, SJOV via WNJ. The primary outcome was the incidence of adverse events, including sedation-related adverse events [SRAEs, hypoxemia (SpO2 = 75-89% lasted less than 60 s); severe hypoxemia (SpO2 < 75% at any time or SpO2 < 90% lasted more than 60 s] and subclinical respiratory depression (SpO2 = 90-95%). Other intraoperative and post-operative adverse events were also recorded as secondary outcomes. RESULTS: Compared with the N group, the incidence of hypoxemia and subclinical respiratory depression in the WS group was significantly lower (21% vs. 4%, P = 0.005; 27% vs. 6%, P = 0.002). Compared with Group W, the incidence of hypoxemia and subclinical respiratory depression in Group WS was also significantly less frequent (20% vs. 4%, P = 0.009; 21% vs. 6%, P = 0.014). No severe hypoxia occurred in the group WS, while four and one instances were observed in the group N and group W respectively. There were no significant differences in other adverse events among the three groups. CONCLUSION: SJOV can effectively improve oxygenation during ERCP in deeply sedated semiprone patients.

Organ Protection by Caloric Restriction Depends on Activation of the De Novo NAD+ Synthesis Pathway.

SIGNIFICANCE STATEMENT: AKI is a major clinical complication leading to high mortality, but intensive research over the past decades has not led to targeted preventive or therapeutic measures. In rodent models, caloric restriction (CR) and transient hypoxia significantly prevent AKI and a recent comparative transcriptome analysis of murine kidneys identified kynureninase (KYNU) as a shared downstream target. The present work shows that KYNU strongly contributes to CR-mediated protection as a key player in the de novo nicotinamide adenine dinucleotide biosynthesis pathway. Importantly, the link between CR and NAD+ biosynthesis could be recapitulated in a human cohort. BACKGROUND: Clinical practice lacks strategies to treat AKI. Interestingly, preconditioning by hypoxia and caloric restriction (CR) is highly protective in rodent AKI models. However, the underlying molecular mechanisms of this process are unknown. METHODS: Kynureninase (KYNU) knockout mice were generated by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and comparative transcriptome, proteome and metabolite analyses of murine kidneys pre- and post-ischemia-reperfusion injury in the context of CR or ad libitum diet were performed. In addition, acetyl-lysin enrichment and mass spectrometry were used to assess protein acetylation. RESULTS: We identified KYNU as a downstream target of CR and show that KYNU strongly contributes to the protective effect of CR. The KYNU-dependent de novo nicotinamide adenine dinucleotide (NAD+) biosynthesis pathway is necessary for CR-associated maintenance of NAD+ levels. This finding is associated with reduced protein acetylation in CR-treated animals, specifically affecting enzymes in energy metabolism. Importantly, the effect of CR on de novo NAD+ biosynthesis pathway metabolites can be recapitulated in humans. CONCLUSIONS: CR induces the de novo NAD+ synthesis pathway in the context of IRI and is essential for its full nephroprotective potential. Differential protein acetylation may be the molecular mechanism underlying the relationship of NAD+, CR, and nephroprotection.

A New Approach to Vascular Screening: Identification of Impaired Vascular Function Using the FMSF Technique.

Arterial blood pressure monitoring plays an important role in preventive medicine, allowing, in selected cases, the identification of vascular dysfunction. In this review, we propose a new non-invasive approach to assessment of the circulatory system, based on its reaction to hypoxia induced by post-occlusive reactive hyperemia (PORH). Three key parameters can be used for vascular screening: the Reactive Hyperemia Response (RHR), which represents the overall reaction of the macro- and microcirculation to transient hypoxia; Hypoxia Sensitivity (HS), which reflects hypoxia-induced activation of myogenic oscillations of the microcirculation; and Normoxia Oscillatory Index (NOI), which characterizes microcirculatory oscillations under normoxia conditions. A method for assessing these parameters, analogous in simplicity to arterial blood pressure measurement, is provided by the Flow Mediated Skin Fluorescence (FMSF) technique. Reference values are proposed based on numerous test measurements.

Place of high-flow nasal oxygen in nonoperating room anesthesia.

PURPOSE OF REVIEW: This article aims to assess the utility of high-flow nasal oxygen (HFNO) therapy in nonoperating room anesthesia (NORA) settings. RECENT FINDINGS: The number of procedural interventions under deep sedation in NORA is still increasing. Administration of oxygen is recommended to prevent hypoxemia and is usually delivered with standard oxygen through nasal cannula or a face mask. HFNO is a simple alternative with a high warmed humidified flow (ranging from 30 to 70 l/min) with a precise fraction inspired of oxygen (ranging from 21 to 100%). Compared to standard oxygen, HFNO has demonstrated efficacy in reducing the incidence of hypoxemia and the need for airway maneuvers. Research on HFNO has primarily focused on its application in gastrointestinal endoscopy procedures. Yet, it has also shown promising results in various other procedural interventions including bronchoscopy, cardiology, and endovascular procedures. However, the adoption of HFNO prompted considerations regarding cost-effectiveness and environmental impact. SUMMARY: HFNO emerges as a compelling alternative to conventional oxygen delivery methods for preventing hypoxemia during procedural interventions in NORA. However, its utilization should be reserved for patients at moderate-to-high risk to mitigate the impact of cost and environmental factors.

Protective Effect of Hydrogen Sulfide on Cerebral Ischemia-Reperfusion Injury.

The brain is the most sensitive organ to hypoxia in the human body. Hypoxia in the brain will lead to damage to local brain tissue. When the blood supply of ischemic brain tissue is restored, the damage will worsen, that is, cerebral ischemia-reperfusion injury. Hydrogen sulfide (H2S) is a gaseous signal molecule and a novel endogenous neuroregulator. Indeed, different concentrations of H2S have different effects on neurons. Low concentration of H2S can play an important protective role in cerebral ischemia-reperfusion injury by inducing anti-oxidative stress injury, inhibition of inflammatory response, inhibition of cell apoptosis, reduction of cerebrovascular endothelial cell injury, regulation of autophagy, and other ways, which provides a new idea for clinical diagnosis and treatment of related diseases. This review aims to report the recent research progress on the dual effect of H2S on brain tissue during cerebral ischemia/reperfusion injury.

Novel transcatheter intervention for iatrogenic cyanosis due to surgical rerouting of inferior vena cava to the left atrium.

Improper identification of the atrial septal defect margins during surgery and inadvertent suturing of the surgical patch to the Eustachian valve of the inferior vena cava (IVC) results in the diversion of inferior venacaval blood to the left atrium causing cyanosis. This complication has been dealt so far with surgery. We report the planning and implementation of a novel transcatheter rediversion of the IVC to the right atrium using a covered stent.

Restrictive versus high-dose oxygenation strategy in post-arrest management following adult non-traumatic cardiac arrest: a meta-analysis.

PURPOSE: Neurological damage is the main cause of death or withdrawal of care in comatose survivors of cardiac arrest (CA). Hypoxemia and hyperoxemia following CA were described as potentially harmful, but reports were inconsistent. Current guidelines lack specific oxygen targets after return of spontaneous circulation (ROSC). OBJECTIVES: The current meta-analysis assessed the effects of restrictive compared to high-dose oxygenation strategy in survivors of CA. METHODS: A structured literature search was performed. Randomized controlled trials (RCTs) comparing two competing oxygenation strategies in post-ROSC management after CA were eligible. The primary end point was short-term survival (≤ 90 days). The meta-analysis was prospectively registered in PROSPERO database (CRD42023444513). RESULTS: Eight RCTs enrolling 1941 patients were eligible. Restrictive oxygenation was applied to 964 patients, high-dose regimens were used in 977 participants. Short-term survival rate was 55.7% in restrictive and 56% in high-dose oxygenation group (8 trials, RR 0.99, 95% CI 0.90 to 1.10, P = 0.90, I2 = 18%, no difference). No evidence for a difference was detected in survival to hospital discharge (5 trials, RR 0.98, 95% CI 0.79 to 1.21, P = 0.84, I2 = 32%). Episodes of hypoxemia more frequently occurred in restrictive oxygenation group (4 trials, RR 2.06, 95% CI 1.47 to 2.89, P = 0.004, I2 = 13%). CONCLUSION: Restrictive and high-dose oxygenation strategy following CA did not result in differences in short-term or in-hospital survival. Restrictive oxygenation strategy may increase episodes of hypoxemia, even with restrictive oxygenation targets exceeding intended saturation levels, but the clinical relevance is unknown. There is still a wide gap in the evidence of optimized oxygenation in post-ROSC management and specific targets cannot be concluded from the current evidence.

High Altitude.

With ascent to high altitude, barometric pressure declines, leading to a reduction in the partial pressure of oxygen at every point along the oxygen transport chain from the ambient air to tissue mitochondria. This leads, in turn, to a series of changes over varying time frames across multiple organ systems that serve to maintain tissue oxygen delivery at levels sufficient to prevent acute altitude illness and preserve cognitive and locomotor function. This review focuses primarily on the physiological adjustments and acclimatization processes that occur in the lungs of healthy individuals, including alterations in control of breathing, ventilation, gas exchange, lung mechanics and dynamics, and pulmonary vascular physiology. Because other organ systems, including the cardiovascular, hematologic and renal systems, contribute to acclimatization, the responses seen in these systems, as well as changes in common activities such as sleep and exercise, are also addressed. While the pattern of the responses highlighted in this review are similar across individuals, the magnitude of such responses often demonstrates significant interindividual variability which accounts for subsequent differences in tolerance of the low oxygen conditions in this environment.

A randomized controlled trial of the intraoperative use of noninvasive ventilation versus supplemental oxygen by face mask for procedural sedation in an electrophysiology laboratory.

PURPOSE: The efficacy of noninvasive ventilation (NIV) during procedures that require sedation and analgesia has not been established. We evaluated whether NIV reduces the incidence of respiratory events. METHODS: In this randomized controlled trial, we included 195 patients with an American Society of Anesthesiologists Physical Status of III or IV during electrophysiology laboratory procedures. We compared NIV with face mask oxygen therapy for patients under sedation. The primary outcome was the incidence of respiratory events determined by a computer-driven blinded analysis and defined by hypoxemia (peripheral oxygen saturation < 90%) or apnea/hypopnea (absence of breathing for 20 sec on capnography). Secondary outcomes included hemodynamic variables, sedation, patient safety (composite scores of major or minor adverse events), and adverse outcomes at day 7. RESULTS: A respiratory event occurred in 89/98 (95%) patients in the NIV group and in 69/97 (73%) patients with face masks (risk ratio [RR], 1.29; 95% confidence interval [CI], 1.13 to 1.47; P < 0.001). Hypoxemia occurred in 40 (42%) patients in the NIV group and in 33 (34%) patients with face masks (RR, 1.21; 95% CI, 0.84 to 1.74; P = 0.30). Apnea/hypopnea occurred in 83 patients (92%) in the NIV group vs 65 patients (70%) with face masks (RR, 1.32; 95% CI, 1.14 to 1.53; P < 0.001). Hemodynamic variables, sedation, major or minor safety events, and patient outcomes were not different between the groups. CONCLUSIONS: Respiratory events were more frequent among patients receiving NIV without any safety or outcome impairment. These results do not support the routine use of NIV intraoperatively. STUDY REGISTRATION: ClinicalTrials.gov (NCT02779998); registered 4 November 2015.

RéSUMé: OBJECTIF: L'efficacité de la ventilation non invasive (VNI) pendant les interventions nécessitant une sédation et une analgésie n'a pas été établie. Nous avons évalué si la VNI réduisait l'incidence des complications respiratoires. MéTHODE: Dans cette étude randomisée contrôlée, nous avons inclus 195 patient·es de statut physique III ou IV selon l'American Society of Anesthesiologists pendant des interventions en laboratoire d'électrophysiologie. Nous avons comparé la VNI à l'oxygénothérapie par masque facial pour les patient·es sous sédation. Le critère d'évaluation principal était l'incidence des complications respiratoires déterminée par une analyse en aveugle assistée par ordinateur et définie par une hypoxémie (saturation périphérique en oxygène < 90 %) ou une apnée/hypopnée (absence de respiration pendant 20 secondes à la capnographie). Les critères d'évaluation secondaires comprenaient les variables hémodynamiques, la sédation, la sécurité des patient·es (scores composites des événements indésirables majeurs ou mineurs) et les issues indésirables au jour 7. RéSULTATS: Un événement respiratoire est survenu chez 89/98 (95 %) patient·es du groupe VNI et chez 69/97 (73 %) patient·es ayant un masque facial (risque relatif [RR], 1,29; intervalle de confiance [IC] à 95 %, 1,13 à 1,47; P < 0,001). Une hypoxémie est survenue chez 40 (42 %) patient·es du groupe VNI et chez 33 (34 %) patient·es ayant un masque facial (RR, 1,21 ; IC à 95 %, 0,84 à 1,74; P = 0,30). Une hypoxémie est survenue chez 40 (42 %) patient·es du groupe VNI et chez 33 (34 %) patient·es ayant un masque facial (RR, 1,21; IC 95 %, 0,84 à 1,74; P = 0,30). Les variables hémodynamiques, la sédation, les événements de sécurité majeurs ou mineurs et les issues pour les patient·es n'étaient pas différents entre les groupes. CONCLUSION: Les complications respiratoires étaient plus fréquentes chez les patient·es recevant une VNI sans aucun impact sur la sécurité ou les issues. Ces résultats n'appuient pas l'utilisation systématique de la VNI en peropératoire. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT02779998); enregistrée le 4 novembre 2015.

Hypoxemia After Endobronchial Valve Deployment for Persistent Air Leak.

Endobronchial valves (EBVs) are a novel, minimally invasive bronchoscopic management technique for persistent air leaks that fail conservative therapy. Currently, 2 EBVs are available in the United States: the Spiration Valve System (Olympus, Redmond, WA) and the Zephyr Valve (Pulmonx, Redwood, CA). These valves are Food and Drug Administration-approved to reduce hyperinflation in emphysematous patients via bronchoscopic lung-volume reduction. However, more recently, the Spiration Valve has been granted a compassionate use exemption through the Food and Drug Administration for persistent postsurgical air leaks. Despite their popularity, these devices are not free from side effects. As an anesthesiologist, it is vital to be aware of the pathophysiology of this patient population so that safe and effective anesthetics may be provided during valve placement. Here, the use of EBVs is discussed in a patient who presented with a persistent air leak after a transthoracic needle aspiration that failed treatment due to persistent hypoxemia, warranting EBV removal.

Pulmonary reperfusion injury in post-palliative intervention of oligaemic cyanotic CHD: a new catastrophic consequence or just revisiting the same old story?

Pulmonary reperfusion injury is a well-recognised clinical entity in the setting pulmonary artery angioplasty for pulmonary artery stenosis or chronic thromboembolic disease, but not much is known about this complication in post-palliative intervention of oligaemic cyanotic CHD. The pathophysiology of pulmonary reperfusion injury in this population consists of both ischaemic and reperfusion injury, mainly resulting in oxidative stress from reactive oxygen species generation, followed by endothelial dysfunction, and cytokine storm that may induce multiple organ dysfunction. Other mechanisms of pulmonary reperfusion injury are "no-reflow" phenomenon, overcirculation from high pressure in pulmonary artery, and increased left ventricular end-diastolic pressure. Chronic hypoxia in cyanotic CHD eventually depletes endogenous antioxidant and increased the risk of pulmonary reperfusion injury, thus becoming a concern for palliative interventions in the oligaemic subgroup. The incidence of pulmonary reperfusion injury varies depending on multifactors. Despite its inconsistence occurrence, pulmonary reperfusion injury does occur and may lead to morbidity and mortality in this population. The current management of pulmonary reperfusion injury is supportive therapy to prevent deterioration of lung injury. Therefore, a general consensus on pulmonary reperfusion injury is necessary for the diagnosis and management of this complication as well as further studies to establish the use of novel and potential therapies for pulmonary reperfusion injury.

Identification of Patient-Related and Procedure-Related Factors Contributing to Hypoxemia in Adult Outpatients Undergoing Esophagogastroduodenoscopy (EGD).

PURPOSE: To assess which patient factors and procedure-related factors contribute to hypoxemia during esophagogastroduodenoscopy (EGD) and determine whether prophylactic oropharyngeal suctioning reduces the rate of hypoxemia when compared to oropharyngeal suctioning when clinically indicated by patient's coughing or secretions. DESIGN: This was a single-site study taking place at a private practice, outpatient facility with no anesthesia trainees present. Patients were randomized to one of two groups based on birth month. After the administration of sedating medications but before the insertion of the endoscope, Group A was oropharyngeal suctioned by either the anesthesia provider or the proceduralist. Group B was oropharyngeal suctioned only when clinically indicated by coughing or visible copious secretions. METHODS: Data were collected on a variety of patient and procedure-related factors. Associations between these factors and hypoxemia during esophagogastroduodenoscopy were analyzed using the statistical analysis system application JMP. After analysis and literature review, a protocol for prevention and treatment of hypoxemia during EGD was proposed. FINDINGS: This study found that chronic obstructive pulmonary disease increases the risk for hypoxemia during esophagogastroduodenoscopy. There were no other statistically significant associations between other factors and hypoxemia. CONCLUSIONS: This study highlights factors that should be evaluated in the future when considering the risk of hypoxemia during EGD. Although not statistically significant, this study's results indicated that prophylactic oropharyngeal suctioning may reduce rates of hypoxemia, as only 1 of 4 cases of hypoxemia occurred in Group A. Additionally, future studies on hypoxemia during monitored anesthesia care for EGD should include an evaluation of the impact of American Society of Anesthesiologists class, history of chronic obstructive pulmonary disease or asthma, body mass index, obstructive sleep apnea, and opioid administration on hypoxemia risk.

[Effect of high flow nasal catheter oxygen to prevent hypoxemia in endoscopic retrograde cholangiopancreatography surgery in aged].

Objective: To explore the effect of high-flow nasal catheter oxygen inhalation in preventing hypoxemia during endoscopic retrograde cholangiopancreatography (ERCP) surgery in elderly patients. Methods: From September 2021 to September 2022, 116 elderly patients (aged ≥ 70 years) who underwent elective ERCP in the Northern Theater General Hospital were prospectively selected, then divided into general nasal catheter oxygen inhalation group [group C, 31 males and 27 females, aged (79.8±6.4) years] and high-flow nasal catheter oxygen inhalation group [group H, 33 males and 25 females, aged (81.4±6.7) years], with 58 patients in each group. All patients were monitored for anesthesia by target-controlled infusion of propofol and remifentanil. The main outcome index was the incidence of intraoperative subclinical hypoxemia (90% ≤ SpO2 < 95%, duration >5 s), hypoxemia (75% < SpO2 < 90%, 5 s < duration ≤ 60 s) and severe hypoxemia (SpO2 < 75% or SpO2 < 90%, duration > 60 s). Secondary observation measures were SpO2 from T0 to T5 (T0, before anesthesia induction; T1, immediately after anesthesia induction; T2, endoscopic introduction; T3, duodenal papula intubation; T4, endoscopic withdrawal; T5, postoperative awakening), the arterial oxygen partial pressure (PaO2), carbon dioxide partial pressure (PaCO2) and pH at T0, 15 min after the induction and T5. Results: The incidence of intraoperative subclinical hypoxemia in group C and group H was 12.0% (7/58) and 3.4% (2/58) respectively, which showed no significant statistical difference (P=0.165) from each other. The incidence of intraoperative hypoxemia in group H was 8.6% (5/58), which was significantly lower than 31.0% (18/58) of group C (P=0.003). Neither group had intraoperative severe hypoxemia. SpO2 of group H were (98.2±0.9)%, (98.2±0.9)%, (97.8±1.7)% and (97.7±1.7)% at T1, T2, T3, T4, which were higher than (96.8±2.1)%, (96.4±3.0)%, (96.1±2.9)% and (96.4±3.4)% in group C (all P<0.05). PaO2 at 15 min after induction in group H was (240.5±46.7) mmHg (1 mmHg=0.133 kPa), which was higher than that of group C (170.6±33.4) mmHg (P<0.001). There was no statistically significant difference in pH and PaCO2 between the two groups of patients at each timepoint. Conclusion: High flow nasal catheter oxygen can effectively reduce the incidence of hypoxemia in ERCP in elderly patients.

Efficacy of Early Treatment With Favipiravir on Disease Progression Among High-Risk Patients With Coronavirus Disease 2019 (COVID-19): A Randomized, Open-Label Clinical Trial.

BACKGROUND: The role of favipiravir in preventing disease progression in coronavirus disease 2019 (COVID-19) remains uncertain. We aimed to determine its effect in preventing disease progression from nonhypoxia to hypoxia among high-risk COVID-19 patients. METHODS: This was an open-label, randomized clinical trial conducted at 14 public hospitals across Malaysia (February-July 2021) among 500 symptomatic, RT-PCR-confirmed COVID-19 patients, aged ≥50 years with ≥1 comorbidity, and hospitalized within first 7 days of illness. Patients were randomized 1:1 to favipiravir plus standard care or standard care alone. Favipiravir was administered at 1800 mg 2×/day on day 1 followed by 800 mg 2×/day until day 5. The primary endpoint was rate of clinical progression from nonhypoxia to hypoxia. Secondary outcomes included rates of mechanical ventilation, intensive care unit (ICU) admission, and in-hospital mortality. RESULTS: Of 500 patients randomized (mean [SD] age, 62.5 [8.0] years; 258 women [51.6%]; 251 [50.2%] had COVID-19 pneumonia), 487 (97.4%) patients completed the trial. Clinical progression to hypoxia occurred in 46 (18.4%) patients on favipiravir plus standard care and 37 (14.8%) on standard care alone (OR, 1.30; 95% CI: .81-2.09; P = .28). All 3 prespecified secondary endpoints were similar between both groups. Mechanical ventilation occurred in 6 (2.4%) vs 5 (2.0%) (OR, 1.20; 95% CI: .36-4.23; P = .76), ICU admission in 13 (5.2%) vs 12 (4.8%) (OR, 1.09; 95% CI: .48-2.47; P = .84), and in-hospital mortality in 5 (2.0%) vs 0 (OR, 12.54; 95% CI: .76-207.84; P = .08) patients. CONCLUSIONS: Among COVID-19 patients at high risk of disease progression, early treatment with oral favipiravir did not prevent their disease progression from nonhypoxia to hypoxia. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov (NCT04818320).

Individualised positive end-expiratory pressure in abdominal surgery: a systematic review and meta-analysis.

BACKGROUND: Individualised positive end-expiratory pressure (PEEP) may optimise pulmonary compliance, thereby potentially mitigating lung injury. This meta-analysis aimed to determine the impact of individualised PEEP vs fixed PEEP during abdominal surgery on postoperative pulmonary outcomes. METHODS: Medical databases (PubMed, Embase, Web of Science, ScienceDirect, Google Scholar, and the China National Knowledge Infrastructure) were searched for RCTs comparing fixed vs individualised PEEP. The composite primary outcome of pulmonary complications comprised hypoxaemia, atelectasis, pneumonia, and acute respiratory distress syndrome. Secondary outcomes included oxygenation (PaO2/FiO2) and systemic inflammatory markers (interleukin-6 [IL-6] and club cell protein-16 [CC16]). We calculated risk ratios (RRs) and mean differences (MDs) with 95% confidence interval (CI) using DerSimonian and Laird random effects models. Cochrane risk-of-bias tool was applied. RESULTS: Ten RCTs (n=1117 patients) met the criteria for inclusion, with six reporting the primary endpoint. Individualised PEEP reduced the incidence of overall pulmonary complications (141/412 [34.2%]) compared with 183/415 (44.1%) receiving fixed PEEP (RR 0.69 [95% CI: 0.51-0.93]; P=0.016; I2=43%). Risk-of-bias analysis did not alter these findings. Individualised PEEP reduced postoperative hypoxaemia (74/392 [18.9%]) compared with 110/395 (27.8%) participants receiving fixed PEEP (RR 0.68 [0.52-0.88]; P=0.003; I2=0%) but not postoperative atelectasis (RR 0.93 [0.81-1.07]; P=0.297; I2=0%). Individualised PEEP resulted in higher PaO2/FiO2 (MD 20.8 mm Hg [4.6-36.9]; P=0.012; I2=80%) and reduced systemic inflammation (lower plasma IL-6 [MD -6.8 pg ml-1; -11.9 to -1.7]; P=0.009; I2=6%; and CC16 levels [MD -6.2 ng ml-1; -8.8 to -3.5]; P<0.001; I2=0%) at the end of surgery. CONCLUSIONS: Individualised PEEP may reduce pulmonary complications, improve oxygenation, and reduce systemic inflammation after abdominal surgery. CLINICAL TRIAL REGISTRATION: CRD42021277973.