Non-invasive ventilation for acute hypoxemic respiratory failure,including COVID-19

Optimal initial non-invasive management of acute hypoxemic respiratory failure(AHRF),of both coronavirus disease 2019(COVID-19)and non-COVID-19 etiologies,has been the subject of significant discussion.Avoidance of endotracheal intubation reduces related complications,but maintenance of spontaneous breathing with intense respiratory effort may increase risks of patients’self-inflicted lung injury,leading to delayed intubation and worse clinical outcomes.High-flow nasal oxygen is currently recommended as the optimal strategy for AHRF management for its simplicity and beneficial physiological effects.Non-invasive ventilation(NIV),delivered as either pressure support or continuous positive airway pressure via interfaces like face masks and helmets,can improve oxygenation and may be associated with reduced endotracheal intubation rates.However,treatment failure is common and associated with poor outcomes.Expertise and knowledge of the specific features of each interface are necessary to fully exploit their potential benefits and minimize risks.Strict clinical and physiological monitoring is necessary during any treatment to avoid delays in endotracheal intubation and protective ventilation.In this narrative review,we analyze the physiological benefits and risks of spontaneous breathing in AHRF,and the characteristics of tools for delivering NIV.The goal herein is to provide a contemporary,evidence-based overview of this highly relevant topic.

Effects of inhaled nitric oxide in neonatal hypoxemic respiratory failure from a multicenter controlled trial

Background Hypoxemic respiratory failure （HRF） is one of the most common causes for neonatal infants requiring aggressive respiratory support. Inhaled nitric oxide （iNO） has been established routinely as an adjunct to conventional respiratory support in developed countries. The aim of this study was to investigate effects of iNO in neonates with HRF in resource limited condition with no or limited use of surfactant, high frequency oscillatory ventilation （HFOV） and extracorporeal membrane oxygenation.Methods A non-randomized, open, controlled study of efficacy of iNO was conducted over 18 months. Eligible term and near-term neonates from 28 hospitals with HRF （oxygenation index ＞15） were enrolled prospectively into two groups as either iNO or control. Oxygenation improvement and mortality as primary endpoint were determined in relation with dosing and timing of iNO, severity of underlying diseases, complications and burden. Intention-to-treat principle was adopted for outcome assessment. Response to iNO at 10 or 20 parts per million （ppm） was determined by oxygenation in reference to the control （between-group） and the baseline （within-group）.Results Compared to 93 controls, initial dose of iNO at 10 ppm in 107 treated infants significantly improved oxygenation from first hour （P=0.046）, with more partial- and non-responders improved oxygenation with subsequent 20ppm NO （P=0.018）. This effect persisted on days 1 and 3, and resulted in relatively lower mortalities （11.2% vs. 15%）whereas fewer were treated with surfactant （10% vs. 27%）,HFOV （＜5%） or postnatal corticosteroids （＜10%） in both groups. The overall outcomes at 28 days of postnatal life in the iNO-treated was not related to perinatal asphyxia,underlying diseases, severity of hypoxemia, or complications,but to the early use of iNO. The cost of hospital stay was not significantly different in both groups.Conclusions With relatively limited use of surfactant and/or HFOV in neonatal HRF, significantly more responders were found in the iNO-treated patients as reflected by improved oxygenation in the first three days over the baseline level. It warrants a randomized, controlled trial for assessment of appropriate timing and long-term outcome of iNO.

Efficacy and safety of awake prone positioning in the treatment of non-intubated spontaneously breathing patients with COVID-19-related acute respiratory failure:A systematic review and meta-analysis

Background Since the beginning of the coronavirus disease 2019(COVID-19)pandemic,prone positioning has been widely applied for non-intubated,spontaneously breathing patients.However,the efficacy and safety of prone positioning in non-intubated patients with COVID-19-related acute hypoxemic respiratory failure remain unclear.We aimed to systematically analyze the outcomes associated with awake prone positioning(APP).Methods We conducted a systematic literature search of PubMed/MEDLINE,Cochrane Library,Embase,and Web of Science from January 1,2020,to June 3,2022.This study included adult patients with acute respiratory failure caused by COVID-19.The Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines were followed,and the study quality was assessed using the Cochrane risk-of-bias tool.The primary outcome was the reported cumulative intubation risk across randomized controlled trials(RCTs),and the effect estimates were calculated as risk ratios(RRs;95%confidence interval[CI]).Results A total of 495 studies were identified,of which 10 fulfilled the selection criteria,and 2294 patients were included.In comparison to supine positioning,APP significantly reduced the need for intubation in the overall population(RR=0.84,95%CI:0.74–0.95).The two groups showed no significant differences in the incidence of adverse events(RR=1.16,95%CI:0.48–2.76).The meta-analysis revealed no difference in mortality between the groups(RR=0.93,95%CI:0.77–1.11).Conclusions APP was safe and reduced the need for intubation in patients with respiratory failure associated with COVID-19.However,it did not significantly reduce mortality in comparison to usual care without prone positioning.

Rapid killer:Lung squamous cell cancer

Background:Lung cancer is one of the leading causes of death despite improvement in treatment modalities such as immunotherapy with chemotherapy and precise radiotherapy.NSCLC is a heterogeneous group of diseases that differs in cytology and includes adenocarcinoma,squamous cell carcinoma,bronchioloalveolar carcinoma,and poorly differentiated carcinoma.Usually,NSCLC,in contrast to SCLC,spreads locally,and the doubling time of squamous cell carcinoma is 133 days which classifies it as a relatively slow-growing tumor.Case presentation:We present the case of a 72-year-old male,recently diagnosed with squamous cell carcinoma in the right upper lobe along with secondary deposits.Few days after diagnosis,the patient had severe respiratory distress.This endobronchial tumor has increased significantly in size upon bronchoscopic visualization causing a complete obstruction of his right main bronchus and hypoxemic respiratory failure requiring intubation.Conclusion:To our knowledge,there are few reported cases where lung adenocarcinoma progressed rapidly over days.Squamous cell carcinoma usually takes 3 to 6 months to double in size,but in our case,the progression was very fast.In the last decade,it was confirmed that the doubling time of a tumor is an independent factor in the prognosis of lung cancer patients.On the other hand,further studies are needed to identify genes associated with rapid progression and a worse prognosis for lung squamous cell carcinoma.Hence,this aggressive tumor is a“rapid killer.”