Airway stenting for liberation from positive pressure ventilation in patients with central airway obstruction presenting with acute respiratory failure.

BACKGROUND: Central airway obstruction (CAO) can lead to acute respiratory failure (RF) necessitating positive pressure ventilation (PPV). The efficacy of airway stenting to aid liberation from PPV in patients with severe acute RF has been scarcely published. We present a systematic review and our recent experience. METHODS: A systematic review of PubMed was performed, and a retrospective review of cases performed at our two institutions from 2018 to 2022 in adult patients who needed stent insertion for extrinsic or mixed CAO complicated by RF necessitating PPV. RESULTS: Fifteen studies were identified with a total of 156 patients. The weighted mean of successful liberation from PPV post-stenting was 84.5% and the median survival was 127.9 days. Our retrospective series included a total of 24 patients. The most common etiology was malignant CAO (83%). The types of PPV used included high-flow nasal cannula (HFNC) (21%), non-invasive ventilation (NIV) (17%) and Invasive Mechanical Ventilation (62%). The overall rate of successful liberation from PPV was 79%, with 55% of HFNC and NIV cases being liberated immediately post-procedure. The median survival of the patients with MCAO that were successfully liberated from PPV was 74 days (n = 16, range 3-893 days), and for those with that failed to be liberated from PPV, it was 22 days (n = 4, range 9-26 days). CONCLUSION: In patients presenting with acute RF from extrinsic or mixed morphology CAO requiring PPV, airway stenting can successfully liberate most from the PPV. This may allow patients to receive pathology-directed treatment and better end-of-life care.

Smoking and home oxygen therapy: a review and consensus statement from a multidisciplinary Swedish taskforce.

BACKGROUND: Home oxygen therapy (HOT) improves survival in patients with hypoxaemic chronic respiratory disease. Most patients evaluated for HOT are former or active smokers. Oxygen accelerates combustion and smoking may increase the risk of burn injuries and fire hazards; therefore, it is considered a contraindication for HOT in many countries. However, there is variability in the practices and policies regarding this matter. This multidisciplinary Swedish taskforce aimed to review the potential benefits and risks of smoking in relation to HOT, including medical, practical, legal and ethical considerations. METHODS: The taskforce of the Swedish Respiratory Society comprises 15 members across respiratory medicine, nursing, medical law and ethics. HOT effectiveness and adverse risks related to smoking, as well as practical, legal and ethical considerations, were reviewed, resulting in five general questions and four PICO (population-intervention-comparator-outcome) questions. The strength of each recommendation was rated according to the GRADE (grading of recommendation assessment, development and evaluation) methodology. RESULTS: General questions about the practical, legal and ethical aspects of HOT were discussed and summarised in the document. The PICO questions resulted in recommendations about assessment, management and follow-up of smoking when considering HOT, if HOT should be offered to people that meet the eligibility criteria but who continue to smoke, if a specific length of time of smoking cessation should be considered before assessing eligibility for HOT, and identification of areas for further research. CONCLUSIONS: Multiple factors need to be considered in the benefit/risk evaluation of HOT in active smokers. A systematic approach is suggested to guide healthcare professionals in evaluating HOT in relation to smoking.

Application of high-flow nasal cannula in fibreoptic bronchoscopy after congenital heart surgery: a retrospective cohort study.

BACKGROUND: The purpose of this study was to compare the effectiveness and safety of high-flow nasal cannula (HFNC) and conventional oxygen therapy (COT) in fibreoptic bronchoscopy (FB) after congenital heart surgery (CHS) in children. METHODS: We did a retrospective cohort study using patients from the electronic medical record system of Fujian Children's Hospital in China. The study population was children who underwent FB in the cardiac intensive care unit after CHS for 1 year (May 2021-May 2022). Children were classified into HFNC and COT groups according to their oxygen therapy during FB. The primary outcome was oxygenation indices during FB, including pulse oximeter oxygen saturation (SpO2) and transcutaneous oxygen tension (TcPO2) during FB. Secondary outcomes were the number of interruptions during FB and their causes, and complications after FB. RESULTS: We identified 107 children from the electronic medical record system, and 102 children after CHS were finally included in the study (53 in the HFNC group and 49 in the COT group). During the FB examination, TcPO2 and SpO2 were significantly higher in the HFNC group than in the COT group (TcPO2: 90.3±9.3 vs 80.6±11.1 mm Hg; SpO2: 95.6±2.5 vs 92.1%±2.0%, p<0.001) and the transcutaneous carbon dioxide tension was significantly lower than in the COT group (39.6±3.0 vs 43.5±3.9 mm Hg, p<0.001). During the FB, a total of 20 children in the COT group had 24 interruptions, and 8 children in the HFNC group had 9 interruptions (p=0.001). In terms of postoperative complications, eight cases had complications in the COT group and four complications in the HFNC group (p=0.223). CONCLUSIONS: Among children undergoing FB after CHS, the application of HFNC was associated with better oxygenation and fewer procedural interruptions compared with COT, without an increased risk of postoperative complications.

Comparing nasopharyngeal apnoeic oxygenation at 18 l/min to preoxygenation alone in obese patients - A randomised controlled study.

STUDY OBJECTIVE: Investigate a low-cost, nasopharyngeal apnoeic oxygenation technique, establish its efficacy, and compare it to preoxygenation only in an obese population. The study's hypothesis was that nasopharyngeal apnoeic oxygenation at 18 l.min-1 would significantly prolong safe apnoea time compared to preoxygenation alone. DESIGN: Randomised controlled study. SETTING: Theatre complex of a resource constrained hospital. PATIENTS: 30 adult, obese (BMI ≥ 35 kg.m-2) patients presenting for elective surgery. Patients with limiting cardio-respiratory disease, suspected difficult airway, risk of aspiration, and that were pregnant, were excluded. Patients were allocated by block randomisation in a 1:2 ratio to a preoxygenation-only (No-AO) and an intervention group (NPA-O2). INTERVENTIONS: All patients were preoxygenated to an Et-O2 > 80%, followed by a standardised induction. The intervention group received oxygen at 18 l.min-1 via the nasopharyngeal catheter intervention. The desaturation process was documented until an SpO2 of 92% or 600 s was reached. MEASUREMENTS: Baseline demographic and clinical characteristics were collected. The primary outcome was safe apnoea time, defined as the time taken to desaturate to an SpO2 of 92%. Secondary outcomes were rate of carbon dioxide accumulation and factors affecting the risk of desaturation. MAIN RESULTS: The study was conducted in a morbidly obese population (NoAO = 41,1 kg.m-2; NPA-O2 = 42,5 kg.m-2). The risk of desaturation was signifantly lower in the intervention group (Hazzard Ratio = 0,072, 95% CI[0,019-0,283]) (Log-Rank test, p < 0.001). The median safe apnoea time was significantly longer in the intervention group (NoAO = 262 s [IQR 190-316]; NPA-O2 = 600 s [IQR 600-600]) (Mann-Whitney-U test, p < 0.001). The mean rate of CO2 accumalation was significantly slower in the intervention group (NoAO = 0,47 ± 0,14 kPa.min-1; NPA-O2 = 0,3 ± 0,09 kPa.min-1) (t-test, p = 0.003). There were no statistically significant risk factors associated with an increased risk of desaturation found. CONCLUSIONS: Nasopharyngeal apnoeic oxygenation at 18 l/min prolongs safe apnoea time, compared to preoxygenation alone, and reduces the risk of desaturation in morbidly obese patients. CLINICAL TRIAL REGISTRATION: PACTR202202665252087; WC/202004/007.

Transnasal Humidified Rapid Insufflation Ventilatory Exchange in children requiring emergent intubation (Kids THRIVE): a statistical analysis plan for a randomised controlled trial.

The placement of an endotracheal tube for children with acute or critical illness is a low-frequency and high-risk procedure, associated with high rates of first-attempt failure and adverse events, including hypoxaemia. To reduce the frequency of these adverse events, the provision of oxygen to the patient during the apnoeic phase of intubation has been proposed as a method to prolong the time available for the operator to insert the endotracheal tube, prior to the onset of hypoxaemia. However, there are limited data from randomised controlled trials to validate the efficacy of this technique in children. The technique known as transnasal humidified rapid insufflation ventilatory exchange (THRIVE) uses high oxygen flow rates (approximately 2 L/kg/min) delivered through nasal cannulae during apnoea. It has been shown to at least double the amount of time available for safe intubation in healthy children undergoing elective surgery. The technique and its application in real time have not previously been studied in acutely ill or injured children presenting to the emergency department or admitted to an intensive care unit. The Kids THRIVE trial is a multicentre, international, randomised controlled trial (RCT) in children less than 16 years old undergoing emergent intubation in either the intensive care unit or emergency department of participating hospitals. Participants will be randomised to receive either the THRIVE intervention or standard care (no apnoeic oxygenation) during their intubation. The primary objective of the trial is to determine if the use of THRIVE reduces the frequency of oxygen desaturation and increases the frequency of first-attempt success without hypoxaemia in emergent intubation of children compared with standard practice. The secondary objectives of the study are to assess the impact of the use of THRIVE on the rate of adverse events, length of mechanical ventilation and length of stay in intensive care. In this paper, we describe the detailed statistical analysis plan as an update of the previously published protocol.

"This is What Lies Ahead". Perspectives of Oxygen-Naïve COPD Patients on Long-Term Oxygen Use. A Qualitative Study.

Purpose: Oxygen is commonly prescribed to patients with severe COPD. However, little is known about the perspectives COPD patients, who do not yet use oxygen, have on this treatment. Patients and Methods: A total of 14 oxygen-naïve patients with COPD Gold stages 3-4 and a high symptom burden participated in semi-structured interviews, in which their beliefs and expectations regarding oxygen therapy were explored. We used conventional content analysis to process our qualitative data. Results: Four main themes were identified: seeking information, expected impact on quality of life, expected social impact and stigma, and last phase of life. Conclusion: The message that home oxygen should be started, was regarded as bad news by most participants. The rationale behind the therapy and the way it is delivered were unknown to most participants. Some participants anticipated smoking-related stigma and social isolation. Misconceptions such as tank explosions, becoming housebound, full dependency on oxygen and an imminent death were common amongst interviewees. Clinicians should be aware of these fears and assumptions when communicating with patients on this subject.

Utility of high-flow nasal oxygen in comparison to conventional oxygen therapy during upper gastrointestinal endoscopic procedures under sedation: A systematic review and meta-analyses.

BACKGROUND: Sedation and analgesia are the integral components of modern-day upper gastrointestinal (GI) endoscopic procedures. Irrespective of the sedative agent, hypoxia is the most commonly encountered unwarranted event with sedation. The current study intends to scrutinize whether high-flow nasal oxygen (HFNO) is advantageous for providing respiratory support during upper GI endoscopic procedures over other conventional low-flow oxygen delivery modalities, e.g. nasal cannula, facemask, etc. METHODS: An extensive screening of electronic databases was done till July 31, 2022, after enlisting in International prospective register of systematic reviews (PROSPERO) (CRD42021245409). Randomized controlled trials (RCT), comparative cohort studies, case series, cross-sectional studies and case-control studies evaluating the utility of HFNO during upper GI endoscopy under sedation were included in this meta-analysis. RESULTS: We retrieved eight randomized control studies and one longitudinal study with 3294 patients. The application of HFNO during endoscopy led to lesser incidence of desaturation spells (odds ratio [OR] = 0.23; 95% CI 0.11-0.48; I2 = 71%), reduced procedural interruption (OR = 0.11; 95% CI 0.02-0.60; I2 = 88%), better nadir SpO2 level during procedure (mean difference [MD] = 3.16; 95% CI 0.54-5.78; I2 = 73%), overall lesser incidence of sedation-related adverse events (OR = 0.63; 95% CI 0.42-0.93; I2 = 25%), with no significant impact on the duration of endoscopy (MD = 0.15; 95% CI - 0.02 to 0.31, I2 = 0%). CONCLUSION: HFNO is a novel option for upper GI endoscopy under sedation. CLINICAL TRIAL NUMBER AND REGISTRY URL: CRD42021245409 ( https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021245409 ).

Comparison of high-flow nasal cannula and conventional oxygen therapy for high-risk patients during bronchoscopy examination: protocol for a randomized controlled trial.

INTRODUCTION: High-flow nasal cannula (HFNC) has been proven to improve oxygenation and avoid intubation in hypoxemic patients. It has also been utilized during endoscopy examination to reduce the incidence of hypoxia. However, little is known about the effects of HFNC versus conventional oxygen therapy (COT) on oxygenation during bronchoscopy examination via nasal route; particularly, no study has compared the use of HFNC with that of COT at similar FIO2 for patients who have high-risk factors of desaturation during bronchoscopy examination. METHODS AND ANALYSIS: This randomized controlled trial will be implemented in four academic centers in China. Patients who have high-risk factors including hypoxemia, hypercapnia, morbid obesity, and narrow airway will be enrolled to use HFNC or COT during bronchoscopy examination. In the HFNC group, the initial gas flow will be set at 50 L/min with a fraction of inspired oxygen (FIO2) at 0.45, if the patient tolerates, the flow can be increased to 60L/min at most, while in the COT group, oxygen flow will be set at 6 L/min via a conventional nasal cannula. After 5 min pre-oxygenation, the bronchoscope will be inserted via the nasal route. Vital signs, oxygenation (SpO2), and transcutaneous CO2 (PtCO2) will be continuously monitored. The primary outcome is the incidence of hypoxemia, defined as SpO2 < 90% for 10 s during bronchoscopy examination, and secondary outcomes include the need for treatment escalation and adverse events. DISCUSSION: Hypoxia is a common complication of bronchoscopy, our study attempted to demonstrate that HFNC may reduce the probability of hypoxia during bronchoscopy in high-risk patients. The results will be disseminated through peer-reviewed journals and national and international conferences. TRIAL REGISTRATION: http://www.chictr.org.cn/ : ChiCTR2100055038. Registered on 31 December 2021.

High-Flow Nasal Cannula for Apneic Oxygenation in Obese Patients for Elective Surgery: A Systematic Review and Meta-Analysis.

BACKGROUND: Obese patients desaturate rapidly during the apneic period after induction of anesthesia for elective surgery. Administration of oxygen using high-flow nasal cannulae (HFNCs) may prevent desaturation in nonobese patients compared to facemask (FM) preoxygenation. The aim of this meta-analysis was to compare the effectiveness of HFNC to FM preoxygenation techniques in reducing preintubation desaturation in obese patients undergoing elective surgery. METHODS: This study protocol was registered on PROSPERO (CRD42022309391). Adult studies that compared HFNC and FM preoxygenation in obese patients requiring general anesthesia for elective surgery were included. The primary outcome was desaturation resulting in oxygen saturation of <92% from induction of anesthesia until intubation. Secondary outcomes included the lowest arterial oxygen content before intubation expressed in mm Hg, safe apnea time expressed in seconds, the lowest oxygen saturation before intubation expressed as a percentage, patient-reported discomfort, the need for rescue ventilation, and the incidence of aspiration of gastric contents during intubation. Risk of bias was assessed using the Cochrane Collaboration tool. Certainty was assessed following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. RESULTS: Six studies including 351 participants were eligible for analysis. There was no difference in odds of oxygen desaturation <92% between HFNC and FM (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.15-1.63; P = .24). The HFNC group had a significantly longer safe apnea time (mean difference [MD], -124.20 with 95% CI, -200.47 to -47.93; P = .001). There was no difference between HFNC and FM in the lowest arterial oxygen content (MD, -23.90; 95% CI, -88.64 to 40.85; P = .47) and the lowest peripheral oxygenation saturation (MD, -0.47 with 95% CI, -5.07 to 4.12; P = .84). HFNC had a lower odd of discomfort than FM (OR, 0.13; 95% CI, 0.03-0.52; P = .004). There was no difference in the odds of aspiration of gastric contents between HFNC and FM (OR, 0.33; 95% CI, 0.01-8.21; P = .50). The risk of bias for our primary and secondary outcomes was low. The GRADE assessment for our primary outcome indicated a low level of certainty. For secondary outcomes, the GRADE assessment indicated a very low certainty for all outcomes except for patient discomfort, which was indicated as a moderate level of certainty. CONCLUSIONS: There may be no difference between HFNC and FM preoxygenation in preventing oxygen desaturation <92% or the lowest oxygen saturation before intubation. Preparation remains important to prevent and manage desaturation during induction of obese patients.

Apnoeic oxygenation in morbid obesity: a randomised controlled trial comparing facemask and high-flow nasal oxygen delivery.

BACKGROUND: Obesity is a risk factor for airway-related incidents during anaesthesia. High-flow nasal oxygen has been advocated to improve safety in high-risk groups, but its effectiveness in the obese population is uncertain. This study compared the effect of high-flow nasal oxygen and low-flow facemask oxygen delivery on duration of apnoea in morbidly obese patients. METHODS: Morbidly obese patients undergoing bariatric surgery were randomly allocated to receive either high-flow nasal (70 L min-1) or facemask (15 L min-1) oxygen. After induction of anaesthesia, the patients were apnoeic for 18 min or until peripheral oxygen saturation decreased to 92%. RESULTS: Eighty patients were studied (41 High-Flow Nasal Oxygen, 39 Facemask). The median apnoea time was 18 min in both the High-Flow Nasal Oxygen (IQR 18-18 min) and the Facemask (inter-quartile range [IQR], 4.1-18 min) groups. Five patients in the High-Flow Nasal Oxygen group and 14 patients in the Facemask group desaturated to 92% within 18 min. The risk of desaturation was significantly lower in the High-Flow Nasal Oxygen group (hazard ratio=0.27; 95% confidence interval [CI], 0.11-0.65; P=0.007). CONCLUSIONS: In experienced hands, apnoeic oxygenation is possible in morbidly obese patients, and oxygen desaturation did not occur for 18 min in the majority of patients, whether oxygen delivery was high-flow nasal or low-flow facemask. High-flow nasal oxygen may reduce desaturation risk compared with facemask oxygen. Desaturation risk is a more clinically relevant outcome than duration of apnoea. Individual physiological factors are likely to be the primary determinant of risk rather than method of oxygen delivery. CLINICAL TRIAL REGISTRATION: NCT03428256.

Impacto de la cánula nasal de alto flujo y la ventilación no invasiva en la fisiología deglutoria: revisión de la literatura / Impact of high-flow nasal cannula and non-invasive ventilation on swallowing physiology: a literature review

El proceso deglutorio requiere de una adecuada coordinación entre respiración y deglución. En el contexto clínico, el uso de dispositivos ventilatorios no invasivos, como la cánula nasal de alto flujo (CNAF) o la ventilación no invasiva (VNI), ha cobrado gran relevancia durante los últimos años. Sin embargo, existe escasa información respecto a la interferencia que estos dispositivos podrían ocasionar en la fisiología deglutoria. En este contexto, y con el objetivo de describir el impacto de la CNAF y la VNI en la fisiología deglutoria, se realizó una revisión de la literatura en PubMed, Medline, Embase, Web of Science, Lilacs y Scielo. Se incorporaron estudios que incluyeran población ≥18 años, con uso de CNAF o VNI. Se excluyeron estudios en población con antecedentes de disfagia, necesidad de intubación, presencia de enfermedad neurológica, neuromuscular o respiratoria, entre otros. Los resultados de los estudios muestran que la CNAF podría disminuir el número de degluciones (en flujos ≥ 20 L/min; p<0,05),disminuir el tiempo medio de activación de la respuesta deglutoria proporcional al flujo empleado (p<0,05), incrementar el riesgo aspirativo en flujos altos (>40 L/min, p<0,05) e incrementar en promedio la duración del cierre del vestíbulo laríngeo (p<0,001). La VNI modo BiPAP, por su parte, podría aumentar el riesgo aspirativo debido al incremento en la tasa de inspiración post deglución (SW-I, p<0,01). Si bien la evidencia disponible es limitada, los resultados aportan información relevante a considerar en el abordaje de usuarios que utilicen estos dispositivos ventilatorios. Futuras investigaciones deberían ser desarrolladas para fortalecer la evidencia presentada.

Deglutition requires adequatecoordination between breathing and swallowing. In the clinical context, the use of non-invasive ventilatory devices such as high-flow nasal cannulas(HFNC) or non-invasive ventilation (NIV) has become highlyrelevantin recent years. However, there is little information regarding howthese devices could interferewith the physiologyof deglutition. This study aimedto describe the impact of HFNC and NIV on swallowing physiology. To this end, aliterature review was carried out usingPubMed, Medline, Embase, Web of Science, Lilacs,and Scielo. Studies performed onpopulations≥18 years old where HFNC or NIV were used were included. Studies where thepopulation hada history of dysphagia, need for intubation, and presentedneurological, neuromuscular,or respiratory diseases, among others, were excluded. The results show that HFNC could decrease the swallowing rate(with flows≥ 20 L/min; p<.05), decrease the mean activation time of the swallowing reflex in proportion to the flow (p<.05), increase the risk of aspiration when usinghigherflows (>40 L/min, p<0.05),and increase the average duration of the laryngeal vestibuleclosure(p<.001).NIV, particularly BiPAP, could increase the risk of aspiration due to the higherrate of post-swallowing inspiration (SW-I, p<.01). Although the evidence available on this matter is limited, theseresults offerrelevant information that should beconsideredwhen working with patients who use these ventilatory devices. Furtherresearch should be carriedoutto strengthen the evidence that is provided in this study.

Oxygen-induced hypercapnia: physiological mechanisms and clinical implications.

Oxygen is probably the most commonly prescribed drug in the emergency setting and is a life-saving modality as well. However, like any other drug, oxygen therapy may also lead to various adverse effects. Patients with chronic obstructive pulmonary disease (COPD) may develop hypercapnia during supplemental oxygen therapy, particularly if uncontrolled. The risk of hypercapnia is not restricted to COPD only; it has also been reported in patients with morbid obesity, asthma, cystic fibrosis, chest wall skeletal deformities, bronchiectasis, chest wall deformities, or neuromuscular disorders. However, the risk of hypercapnia should not be a deterrent to oxygen therapy in hypoxemic patients with chronic lung diseases, as hypoxemia may lead to life-threatening cardiovascular complications. Various mechanisms leading to the development of oxygen-induced hypercapnia are the abolition of 'hypoxic drive', loss of hypoxic vasoconstriction and absorption atelectasis leading to an increase in dead-space ventilation and Haldane effect. The international guideline recommends a target oxygen saturation of 88% to 92% in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and other chronic lung diseases at risk of hypercapnia.  Oxygen should be administered only when oxygen saturation is below 88%. We searched PubMed, EMBASE, and the CINAHL from inception to June 2022. We used the following search terms: "Hypercapnia", "Oxygen therapy in COPD", "Oxygen-associated hypercapnia", "oxygen therapy", and "Hypoxic drive". All types of study are selected. This review will focus on the physiological mechanisms of oxygen-induced hypercapnia and its clinical implications.

Incidence of oxygen desaturation using a high-flow nasal cannula versus a facemask during flexible bronchoscopy in patients at risk of hypoxemia: a randomised controlled trial.

BACKGROUND: Patients with obstructive sleep apnoea (OSA), male sex, obesity, older age or hypertension are prone to hypoxemia during flexible bronchoscopy. This study investigated whether using a high-flow nasal cannula (HFNC) could reduce the incidence of oxygen desaturation during bronchoscopy under deep sedation in patients at risk of hypoxemia. METHODS: A total of 176 patients at risk of hypoxemia who underwent flexible bronchoscopy under deep sedation were randomly assigned to two groups: the HFNC group (humidified oxygen was supplied via a high-flow nasal cannula at a rate of 60 L/min and a concentration of 100%, n = 87) and the facemask group (oxygen was supplied via a tight-fitting facemask at a rate of 6 L/min and a concentration of 100%, n = 89). RESULTS: Oxygen desaturation occurred in 4 (4.6%) patients in the HFNC group and 26 (29.2%) patients in the facemask group (P < 0.001). The facemask group required more jaw thrust manoeuvres than the HFNC group (43[48.3%] vs. 5[5.7%], P < 0.001). 8 patients (9.0%) in the facemask group and none in the HFNC group required bag-mask ventilation (P = 0.012). CONCLUSION: The use of an HFNC can reduce the incidence of oxygen desaturation and the requirement for airway intervention in patients at risk of hypoxemia during flexible bronchoscopy under deep sedation. TRIAL REGISTRATION: www.chiCTR.org.cn Identifier: ChiCTR2100044105. Registered 11/03/2021.

Outcomes of Patients with Burns Associated with Home Oxygen Therapy: An Institutional Retrospective Review.

Home oxygen therapy (HOT) burns carry high morbidity and mortality. Many patients are active smokers, which is the most frequent cause of oxygen ignition. We conducted a retrospective review at our institution to characterize demographics and outcomes in this patient population. An IRB-approved single-institution retrospective review was conducted for home oxygen therapy burn patients between July 2016 and January 2021. Demographic and clinical outcome data were compared between groups. We identified 100 patients with oxygen therapy burns. Mean age was 66.6 years with a male to female ratio of 1.3:1 and median burn surface area of 1%. In these patients, 97% were on oxygen for COPD and smoking caused 83% of burns. Thirteen were discharged from the emergency department, 35 observed for less than 24 hours, and 52 admitted. For admitted patients, 69.2% were admitted to the ICU, 37% required intubation, and 11.5% required debridement and grafting. Inhalational injury was found in 26.9% of patients, 3.9% underwent tracheostomy, and 17.3% experienced hospital complications. In-hospital mortality was 9.6% and 7.7% were discharged to hospice. 13.5% required readmission within 30 days. Admitted patients had significantly higher rates of admission to the ICU, intubation, and inhalational injury compared to those that were not admitted (P < .01). Most HOT-related burns are caused by smoking and can result in significant morbidity and mortality. Efforts to educate and encourage smoking cessation with more judicious HOT allocation would assist in preventing these unnecessary highly morbid injuries.

Adverse Effects, Smoking, Alcohol Consumption, and Quality of Life during Long-Term Oxygen Therapy: A Nationwide Study.

Rationale: Long-term oxygen therapy (LTOT) is prescribed for at least 15 hours per day and often used by patients for several years, but knowledge is limited regarding adverse effects, risk exposures, and health-related quality of life (HrQoL) among those treated. Objectives: To determine the prevalence of adverse effects, smoking, and alcohol consumption and their relations to HrQoL among patients treated with LTOT. Methods: This was a cross-sectional survey of a randomized sample of adults with ongoing LTOT in the Swedish National Registry for Respiratory Failure (Swedevox). Patient characteristics and the prevalence of 26 prespecified adverse effects, smoking, and alcohol consumption, were compared between respondents with better and worse HrQoL on the chronic obstructive pulmonary disease assessment test. Results: A total of 151 respondents were included (mean age, 74.7 yr [standard deviation, 8.6 yr]; 58.9% women; median LTOT duration, 2.2 yr [interquartile range, 1.0-3.8 yr]). Characteristics upon starting LTOT were similar between respondents and nonrespondents. Active smoking was very rare (n = 4, 2.6%). For alcohol use, 67.2% of participants reported no consumption during an average week, whereas risk use was reported by 25.8% of men and 16.9% of women. The most prevalent adverse effects were reduced mobility or physical activity (70.9%), dry mouth (69.5%), congestion or nasal drip (61.6%), increased tiredness (57.0%), and dry nose (53.0%). Patients with higher numbers of total and systemic adverse effects experienced worse HrQoL, whereas no associations were found for smoking status or alcohol consumption. The majority (54.8%) of adverse effects were untreated and unreported to health professionals. Conclusions: Adverse effects are common among patients with LTOT and are associated with worse HrQoL. As the majority of adverse effects had not been discussed or treated, structured assessment and management of risk exposures and adverse effects is warranted.

High flow nasal oxygen versus conventional oxygen therapy in gastrointestinal endoscopy with conscious sedation: Systematic review and meta-analysis with trial sequential analysis.

OBJECTIVES: Although conventional oxygen therapy (COT) is widely used, hypoxemia frequently occurs in gastrointestinal endoscopy with conscious sedation and can lead to life-threatening consequences. High flow nasal oxygen (HFNO) has been applied to improve oxygenation in clinical entities. However, its efficacy to prevent hypoxemia in gastrointestinal endoscopy with conscious sedation has not been evaluated. METHODS: We searched databases to identify randomized controlled trials that compared the efficacy of HFNO with COT in gastrointestinal endoscopy with conscious sedation. The primary outcome was hypoxemia. Meta-analyses with trial sequential analysis were performed using a random-effects model. RESULTS: Eight trials with 3212 patients were included. Compared with COT, HFNO significantly reduced the risk of hypoxemia (eight trials; 3212 patients; risk ratio 0.30; 95% confidence interval [CI] 0.13-0.70). Trial sequential analysis showed that the cumulative Z curve did not cross the monitoring or futility boundaries, nor reach the required information size line, indicating that more trials are needed to reach a definitive conclusion. Subgroup analyses indicated the superiority of HFNO over COT with respect to hypoxemia in patients at low risk and high risk. HFNO further improved the lowest oxygen saturation (four trials; 459 patients; mean difference 2.30, 95% CI 0.84-3.77). CONCLUSIONS: Compared with COT, HFNO can reduce the risk of hypoxemia and improve the lowest oxygen saturation in gastrointestinal endoscopy with conscious sedation. However, the results should be interpreted with caution due to substantial heterogeneity and limited evidence. Further studies are needed to verify the preliminary findings.

High-flow versus conventional nasal cannula oxygen supplementation therapy and risk of hypoxia in gastrointestinal endoscopies: a systematic review and meta-analysis.

BACKGROUND: 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). METHODS: 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. RESULTS: 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%).    . CONCLUSION: 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).

Gelsolin Attenuates Neonatal Hyperoxia-Induced Inflammatory Responses to Rhinovirus Infection and Preserves Alveolarization.

Prematurity and bronchopulmonary dysplasia (BPD) increase the risk of asthma later in life. Supplemental oxygen therapy is a risk factor for chronic respiratory symptoms in infants with BPD. Hyperoxia induces cell injury and release of damage-associated molecular patterns (DAMPs). Cytoskeletal filamentous actin (F-actin) is a DAMP which binds Clec9a, a C-type lectin selectively expressed on CD103+ dendritic cells (DCs). Co-stimulation of Clec9a and TLR3 induces maximal proinflammatory responses. We have shown that neonatal hyperoxia (a model of BPD) increases lung IL-12+Clec9a+CD103+ DCs, pro-inflammatory responses and airway hyperreactivity following rhinovirus (RV) infection. CD103+ DCs and Clec9a are required for these responses. Hyperoxia increases F-actin levels in bronchoalveolar lavage fluid (BALF). We hypothesized that the F-actin severing protein gelsolin attenuates neonatal hyperoxia-induced Clec9a+CD103+ DC-dependent pro-inflammatory responses to RV and preserves alveolarization. We exposed neonatal mice to hyperoxia and treated them with gelsolin intranasally. Subsequently we inoculated the mice with RV intranasally. Alternatively, we inoculated normoxic neonatal mice with BALF from hyperoxia-exposed mice (hyperoxic BALF), RV and gelsolin. We analyzed lung gene expression two days after RV infection. For in vitro studies, lung CD11c+ cells were isolated from C57BL/6J or Clec9agfp-/- mice and incubated with hyperoxic BALF and RV. Cells were analyzed by flow cytometry. In neonatal mice, gelsolin blocked hyperoxia-induced Il12p40, TNF-α and IFN-γ mRNA and protein expression in response to RV infection. Similar effects were observed when gelsolin was co-administered with hyperoxic BALF and RV. Gelsolin decreased F-actin levels in hyperoxic BALF in vitro and inhibited hyperoxia-induced D103lo DC expansion and inflammation in vivo. Gelsolin also attenuated hyperoxia-induced hypoalveolarization. Further, incubation of lung CD11c+ cells from WT and Clec9agfp-/- mice with hyperoxic BALF and RV, showed Clec9a is required for maximal hyperoxic BALF and RV induced IL-12 expression in CD103+ DCs. Finally, in tracheal aspirates from mechanically ventilated human preterm infants the F-actin to gelsolin ratio positively correlates with FiO2, and gelsolin levels decrease during the first two weeks of mechanical ventilation. Collectively, our findings demonstrate a promising role for gelsolin, administered by inhalation into the airway to treat RV-induced exacerbations of BPD and prevent chronic lung disease.

Oxygen care and treatment of retinopathy of prematurity in ocular and neurological prognosis.

This retrospective cohort study aimed to investigate the effects of neonatal oxygen care and retinopathy of prematurity (ROP) treatment on ROP-related ocular and neurological prognoses. We included premature infants treated for ROP at a tertiary referral center between January 2006 and December 2019. Demographic and clinical data were collected from electronic medical records. Odds ratios (ORs) of oxygen care- and ROP treatment-related factors were calculated for ocular and neurological comorbidities 3 years after ROP treatment, after adjusting for potential confounders. ROP requiring treatment was detected in 171 eyes (88 infants). Laser treatment for ROP (OR = 4.73, 95% confidence interval [CI] 1.64-13.63) and duration of invasive ventilation (OR = 1.02, 95% CI 1.00-1.03) were associated with an increase in ocular comorbidities, along with a history of neonatal seizure (OR = 28.29, 95% CI 5.80-137.95) and chorioamnionitis (OR = 32.13, 95% CI 5.47-188.74). No oxygen care- or ROP treatment-related factors showed significant odds for neurological comorbidities. Shorter duration of invasive oxygen supply during neonatal care (less than 49 days) and anti-vascular endothelial growth factor injection as the primary treatment for ROP are less likely to cause ocular comorbidities. No association was identified between ROP treatment modalities and the risk of neurological comorbidities.

Factors associated with recurrent wheezing in the first year of life among premature newborns from Neonatal Intensive Care Units / Fatores associados à sibilância recorrente no primeiro ano de vida entre recémnascidos prematuros provenientes de Unidades de Terapia Intensiva Neonatais

Abstract Objectives: to determine the prevalence and factors associated with recurrent wheezing in the first year of life among premature newborns from Neonatal Intensive Care Units, in the city of Montes Claros, northern Minas Gerais. Methods: cross-sectional study, with data collection from medical records of a follow-up clinic, interviews with mothers and, eventually, search in hospital records. Bivariate analyzes were carried out between sociodemographic and clinical characteristics and recurrent wheezing. Variables associated up to the level of 20% were analyzed by binary logistic regression, and associations defined by the Odds Ratio and respective 95% confidence intervals. Only variables associated with a 5% significance level were maintained in the final model of logistic regression. Results: among 277 infants studied, about one fifth (21.3%) were extremely low birth weight preterm and more than half (60.7%) had birth weight below 1500 grams. The prevalence of recurrent wheezing was 14.4% (CI95% = 10.3-18.4). Mechanical ventilation (OR = 2.12; CI95% = 1.09-4.76; p = 0.030) and oxygen therapy time ≥ 15 days (OR = 2.49; CI95%= 1.12-5.00; p = 0.010) were the risk factors for the event. Conclusions: there is a high prevalence of recurrent wheezing in the evaluated group and the associated variables reiterate the risk of prolonged oxygen therapy and mechanical ventilation for premature newborns.

Resumo Objetivos: determinar a prevalência e fatores associados à sibilância recorrente no primeiro ano de vida entre recém-nascidos prematuros egressos de Unidades de Terapia Intensiva Neonatais, na cidade de Montes Claros, norte de Minas Gerais. Métodos: estudo transversal, com coleta de dados em prontuários de ambulatório de seguimento, entrevistas com mães e, eventualmente, consultas aos prontuários hospitalares. Foram realizadas análises bivariadas entre as características sociodemográficas e clínicas e a sibilância recorrente. As variáveis associadas ao desfecho até um nível de significância de p ≤20% foram analisadas por regressão logística binária e as associações definidas pelas Odds Ratios e respectivos intervalos de confiança de 95%. Somente variáveis associadas a um nível de significância de 5% foram mantidas no modelo final de regressão logística. Resultados: entre 277 crianças estudadas, cerca de um quinto (21,3%) eram prematuros de extremo baixo peso e mais da metade (60,7%) tinha peso de nascimento abaixo de 1500 gramas. A prevalência de sibilância recorrente foi de 14,4% (IC95%=10,3-18,4). Ventilação mecânica (OR=2,12; IC95%= 1,09-4,76; p=0,030) e tempo de oxigenioterapia ≥15 dias (OR=2,49; IC95%=1,12-5,00; p=0,010) foram os fatores de risco para o evento. Conclusão: existe uma elevada prevalência de sibilância recorrente no grupo avaliado e as variáveis associadas reiteram o risco do uso prolongado de oxigenioterapia e da ventilação mecânica para recém-nascidos prematuros.