UNASSIGNED: High-flow nasal oxygen (HFNO) is an accepted treatment for severe COVID-19-related acute hypoxaemic respiratory failure (AHRF).
UNASSIGNED: To determine whether treatment outcomes at Groote Schuur Hospital, Cape Town, South Africa, during the third COVID-19 wave would be affected by increased institutional experience and capacity for HNFO and more restrictive admission criteria for respiratory high-care wards and intensive care units.
UNASSIGNED: We included consecutive patients with COVID-19-related AHRF treated with HFNO during the first and third COVID-19 waves. The primary endpoint was comparison of HFNO failure (composite of the need for intubation or death while on HFNO) between waves.
UNASSIGNED: A total of 744 patients were included: 343 in the first COVID-19 wave and 401 in the third. Patients treated with HFNO in the first wave were older (median (interquartile range) age 53 (46 - 61) years v. 47 (40 - 56) years; p<0.001), and had higher prevalences of diabetes (46.9% v. 36.9%; p=0.006), hypertension (51.0% v. 35.2%; p<0.001), obesity (33.5% v. 26.2%; p=0.029) and HIV infection (12.5% v. 5.5%; p<0.001). The partial pressure of arterial oxygen to fraction of inspired oxygen (PaO2 /FiO2 ) ratio at HFNO initiation and the ratio of oxygen saturation/FiO2 to respiratory rate within 6 hours (ROX-6 score) after HFNO commencement were lower in the first wave compared with the third (median 57.9 (47.3 - 74.3) mmHg v. 64.3 (51.2 - 79.0) mmHg; p=0.005 and 3.19 (2.37 - 3.77) v. 3.43 (2.93 - 4.00); p<0.001, respectively). The likelihood of HFNO failure (57.1% v. 59.6%; p=0.498) and mortality (46.9% v. 52.1%; p=0.159) did not differ significantly between the first and third waves.
UNASSIGNED: Despite differences in patient characteristics, circulating viral variant and institutional experience with HFNO, treatment outcomes were very similar in the first and third COVID-19 waves. We conclude that once AHRF is established in COVID-19 pneumonia, the comorbidity profile and HFNO provider experience do not appear to affect outcome.
UNASSIGNED: What the study adds. This study adds to the body of evidence demonstrating the utility of high-flow nasal oxygen (HFNO) in avoiding invasive mechanical ventilation (IMV) in patients with severe COVID-19 hypoxaemic respiratory failure, and shows that this utility remained consistent across different waves of the COVID-19 pandemic.Implications of the study. In resource-constrained settings, HFNO is a feasible non-invasive alternative to IMV and can be employed with favourable and consistent outcomes outside traditional critical care wards. It also confirms that the degree of gas exchange abnormality, and not pre-existing patient-related factors, circulating wave variant or provider experience, is the main predictor of HFNO failure.

BACKGROUND: Hypoxaemia occurs in approximately 30% of children during anaesthesia for flexible bronchoscopy. High-flow nasal oxygen (HFNO) can prolong safe apnoea time and be used in children with abnormal airways. During flexible bronchoscopy, there is limited evidence if HFNO confers advantages over current standard practice in avoiding hypoxaemia. The aim is to investigate feasibility of HFNO use during anaesthesia for flexible bronchoscopy to reduce frequency of rescue oxygenation and hypoxaemia.
METHODS: BUFFALO is a bi-centre, unmasked, randomised controlled, parallel group, protocol for a pilot trial comparing HFNO techniques to standard practice during anaesthesia. Children (n = 81) aged > 37 weeks to 16 years presenting for elective bronchoscopy who fulfil inclusion but not exclusion criteria will be randomised prior to the procedure to HFNO or standard care oxygenation post induction of anaesthesia. Maintenance of anaesthesia with HFNO requires total venous anaesthesia (TIVA) and with standard, either inhalational or TIVA at discretion of anaesthetist in charge of the patient. Outcomes will include the feasibility of recruitment and adherence to trial procedures, acceptability of the intervention of the protocol and completion rates of data collection methods.
CONCLUSIONS: Findings of this trial will determine feasibility to plan for a larger multicentre randomised clinical trial and support the feasibility of the proposed study procedures.
BACKGROUND: BUFFALO trial was registered with Australia and New Zealand Clinical Trials Registry (TRN12621001635853) on 29 November 2021 and commenced recruitment in May 2022. https://www.anzctr.org.au/ . The primary manuscript will be submitted for publication in a peer-reviewed journal.

High-flow nasal cannula (HFNC) oxygen therapy, which is important in noninvasive respiratory support, is increasingly being used in critically ill neonates with respiratory failure because it is comfortable, easy to setup, and has a low incidence of nasal trauma. The advantages, indications, and risks of HFNC have been the focus of research in recent years, resulting in the development of the application. Based on current evidence, we developed guidelines for HFNC in neonates using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). The guidelines were formulated after extensive consultations with neonatologists, respiratory therapists, nurse specialists, and evidence-based medicine experts. We have proposed 24 recommendations for 9 key questions. The guidelines aim to be a source of evidence and reference of HFNC oxygen therapy in clinical practice, and so that more neonates and their families will benefit from HFNC.

The purpose of this research was to demonstrate the effectiveness and clinical outcome of an external carotid artery-radial artery graft-posterior cerebral artery (ECA-RAG-PCA) bypass in the treatment of complex vertebrobasilar artery aneurysms (VBANs) in a single-center retrospective study. An ECA-RAG-PCA bypass may be a last and very important option in the treatment of complex VBANs when conventional surgical clipping or endovascular interventions fail to achieve the desired outcome. This study retrospectively analyzed the clinical presentation, case characteristics, aneurysm location, size and morphology, choice of surgical strategy, complications, clinical follow-up, and prognosis of the patients enrolled. The data involved were analyzed by the appropriate statistical methods. A total of 24 patients with complex VBANs who met the criteria were included in this study. Eighteen (75.0%) were male and the mean age was 54.1 ± 8.83 years. The aneurysms were located in the vertebral artery, the basilar artery, and in the vertebrobasilar artery with simultaneous involvement. All patients underwent ECA-RAG-PCA bypass surgery via an extended middle cranial fossa approach, with 8 (33.3%) undergoing ECA-RAG-PCA bypass only, 3 (12.5%) undergoing ECA-RAG-PCA bypass combined with aneurysm partial trapping, and 12 (50.0%) undergoing ECA-RAG-PCA bypass combined with proximal occlusion of the parent artery. The average clinical follow-up was 22.0 ± 13.35 months. The patency rate of the high-flow bypass was 100%. At the final follow-up, 15 (62.5%) patients had complete occlusion of the aneurysm, 7 (29.2%) patients had subtotal occlusion of the aneurysm, and 2 (8.3%) patients had stable aneurysms. The rate of complete and subtotal occlusion of the aneurysm at the final follow-up was 91.7%. The clinical prognosis was good in 21 (87.5%) patients and no procedure-related deaths occurred. Analysis of the good and poor prognosis groups revealed a statistically significant difference in aneurysm size (P = 0.034, t-test). Combining the results of this study and the clinical experience of our center, we propose a surgical algorithm and strategy for the treatment of complex VBANs.The technical approach of ECA-RAG-PCA bypass for complex VBANs remains important, even in an era of rapid advances in endovascular intervention. When conventional surgical clipping or endovascular intervention has failed, an ECA-RAG-PCA bypass plays a role that cannot be abandoned and is a very important treatment option of last resort.

Headache is one of the most common causes of emergency department (ED) visits. High-flow oxygen therapy is becoming more attractive as a treatment option because it is safe, effective, and cheap. We aimed to compare the effectiveness of high and medium-flow oxygen therapies with placebo for treating primary headache disorders among middle-aged patients.
This prospective, double-blind, placebo-controlled, crossover designed, randomized study was conducted at a regional tertiary hospital\'s ED. Patients who were treated for primary headache disorder in the ED were evaluated at the time of diagnosis and subsequently included in the study upon their next ED visit. Four different treatment methods were administered; 1) high-flow oxygen (15 L/min oxygen), 2) medium-flow oxygen (8 L/min oxygen), 3) high-flow room air as placebo (15 L/min room air), 4) medium-flow room air as placebo (8 L/min room air). All four treatment methods were administered to all patients included in the study, at four separate ED visits. Patients\' data, including demographics, medical history, additional complaints, Visual Analogue Scale (VAS) score, and physical examination findings were recorded by the treating physician.
One hundred and four patients with a mean age of 35.14 ± 9.1 years, were included in the study. Patients who received oxygen therapy had a significantly lower VAS score at all control points (15, 30, and 60 min) when compared with placebo (p < 0.001). This difference in scores reached its maximum at 30 min. There was not a significant statistical difference between the high-flow or mid-flow therapies (p > 0.05). It was determined that patients who received placebo therapy were more likely to revisit ED (p < 0.05). There was not a significant statistical difference between the high-flow or mid-flow therapy groups in terms of revisit (p > 0.05) and the 30th-minute analgesia requirement (p > 0.05). Pain duration was significantly less in patients who received oxygen therapy (p < 0.05). Patients who received high-flow oxygen therapy spent less time in the ED (p < 0.001).
Oxygen therapy could be a beneficial treatment option for middle-aged patients with primary headache disorders. Based on the results obtained from high and mid-flow oxygen therapies, it may be more appropriate to begin treatment with mid-flow oxygen.

Survival of preterm infants has increased steadily over recent decades, primarily due to improved outcomes for those born before 28 weeks of gestation. However, this has not been matched by similar improvements in longer-term morbidity. One of the key long-term sequelae of preterm birth remains bronchopulmonary dysplasia (also called chronic lung disease of prematurity), contributed primarily by the effect of early pulmonary inflammation superimposed on immature lungs. Non-invasive modes of respiratory support have been rapidly introduced providing modest success in reducing the incidence of bronchopulmonary dysplasia when compared with invasive mechanical ventilation, and improved clinical practice has been reported from population-based studies. We present a comprehensive review of the key modes of non-invasive respiratory support currently used in preterm infants, including their mechanisms of action and evidence of benefit from clinical trials.

Tracheal resection and reconstruction are the most effective treatments for tracheal stenosis, but the difficulties are surgery and maintaining ventilation performed on the patient\'s same airway. High-flow oxygen has begun to be applied to prolong the apnoea time in the tracheal anastomosis period for tracheal resection and reconstruction. This study aims to evaluate the effectiveness of apneic conditions with high-flow oxygen as the sole method of gas exchange during anastomosis construction.
A prospective study was performed on 16 patients with tracheal stenosis, with ages ranging from 19 to 70, who underwent tracheal resection and reconstruction from April 2019 to August 2020 in 108 Military Central Hospital. During the anastomosis phase using high flow oxygen of 35-40 l.min-1 delivered across the open tracheal with an endotracheal tube (ETT) at the glottis in apnoeic conditions.
The mean (SD) apnoea time was 20.91 (2.53) mins. Mean (SD) time anastomosis was 22.9 (2.41) mins. The saturation of oxygen was stable during all procedures at 98-100%. Arterial blood gas analysis showed mean (SD) was hypercapnia and acidosis acute respiratory after 10 mins of apnoea and 20 mins apnoea respectively. However, after 15 mins of ventilation, the parameters are ultimately returned to normal. All 16 patients were extubated early and safely at the end of the operation. There were no complications, such as bleeding, hemothorax, pneumothorax, or barotrauma.
High-flow oxygen across the open tracheal under apnoeic conditions can provide a satisfactory gas exchange to allow tubeless anesthesia for tracheal resection and reconstruction.

OBJECTIVE: Our study aimed to identify predictive factors for malignant post-treatment edema and hemorrhage in patients who underwent microsurgical treatment of arteriovenous malformation (AVM) in our institution.
METHODS: The study included 72 patients treated by microsurgery for cerebral symptomatic and/or ruptured AVM between 2010 and 2020. Six patients developed postprocedural malignant edema and hemorrhage (group M); the other 66 patients had no malignant edema and hemorrhage (group NM). In each patient, flow was assessed indirectly by summing the diameters of all feeding arteries to obtain an overall diameter (ODA), and similarly for draining veins (ODV). High-flow was defined as a delay between feeding artery injection and draining vein injection (DAV)<1 second on dynamic digital subtraction angiography. Univariate analysis was performed.
RESULTS: Mean ODA and ODV were respectively 11mm (±8.2) and 11mm (±5.3) in group M and 2.9mm (±1.4) and 3.7mm (±1.3) in group NM (P=0.001). High-flow AVM was demonstrated in 4 out of 5 patients (85%) in group M and in 14 out of 55 (25%) in group NM (P=0.02). Associated aneurysm was seen in 5 patients in group M (83%) and in 11 in group NM (17%) (P=0.001).
CONCLUSIONS: High-flow AVM may be associated with higher risk of postoperative edema and hemorrhage. Multidisciplinary discussion is mandatory in these cases, to define a pre-therapeutic plan for progressive staged vascular malformation occlusion.

Gastrointestinal endoscopy (GIE) represents a mainstay diagnostic and therapeutic procedure in clinical practice. Hypoxemia constitutes a major complication for endoscopists. Emerging evidence supports the utilization of high-flow nasal cannula (HFNC) over conventional nasal cannula (CNC) for avoidance of hypoxemia. Our aim was to compare the hypoxemia risk in patients undergoing GIE with HFNC versus CNC oxygen supplementation recruited by randomized controlled trials (RCTs).
We searched in medical databases PubMed, EMBASE and Cochrane to identify RCTs investigating the abovementioned association. Enrolled studies were evaluated for risk of bias and inserted into a random effects model for meta-analysis; subgroup analyses and publication bias were also assessed.
Out of 271 articles, five RCTs were eligible (patients n=2656, HFNC 1299 and CNC 1357). A statistically significant reduced relative risk (RR) of hypoxemia among HFNC patients was revealed (RR=0.18, CI95%: 0.05-0.61), whilst with high heterogeneity (I2:79.94%, p<0.01). Patients undergoing upper GIE with HFNC displayed a significantly lower hypoxemia risk (96%, p<0.001, I2:15.59%), even after exclusion of endoscopic retrograde cholangiopancreatography cases (RR:0.03, CI95%:0.01-0.21), albeit with higher heterogeneity (I2:41.82%).    .
Patients undergoing upper GIE with HFNC experience significantly less hypoxemia burden than CNC counterparts. Further research is warranted to target optimal safety during endoscopy.Abbreviations: ASA, American Society of Anesthesiologists; ASGE, American Society for Gastrointestinal Endoscopy; BMI, Body Mass Index; CI, confidence interval; CNC, conventional nasal cannula; ERCP, endoscopic retrograde cholangiopancreatography; FiO2, fraction of inspired O2; GI, gastrointestinal; GIE, gastrointestinal endoscopies; HFNC, High-Flow nasal cannula; ICU, intensive care unit; PEEP, positive end-expiratory pressure; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analysis; RCTs, randomized control trials; RR, relative risk (or risk ratio).

At the start of the COVID-19 pandemic, early intubation was recommended on the basis of worldwide observations of severe hypoxemia. However, some patients were ultimately able to benefit from high-flow nasal cannula (HFNC) and thus avoid intubation. During the \"second wave\" (September to December 2020 in France), some emergency departments implemented HFNC in patients with severe COVID-19. The question then arose regarding the transfer of these most serious patients to intensive care units (ICU) and of the respiratory modalities to be used during this transfer. To assess the feasibility of interhospital transfers of COVID-19 patients needing HFNC, we conducted a bi-centric prospective observational study of all medical transfers of patients needing HFNC with the Chambéry and Angers (France) mobile emergency and intensive care service (SMUR) during the \"second wave\" of the COVID-19 pandemic in France. Analysis of these 42 patients showed no significant variation in the respiratory requirements during the transfer. Overall, 52% of patients were intubated during their stay in ICU, including three patients intubated before or during transfer. Interhospital transfer with HFNC is very high-risk, and intubation remains indicated in the most unstable patients. However, 48% of patients benefited from HFNC and were thus able to avoid intubation during their transfer and ICU stay; for these patients, intubation would probably have been indicated in the absence of available HFNC techniques.