Emergency and difficult tracheal intubations are hazardous undertakings where successive laryngoscopy–hypoxaemia–re-oxygenation cycles can escalate to airway loss and the ‘can't intubate, can't ventilate’ scenario. Between 2013 and 2014, we extended the apnoea times of 25 patients with difficult airways who were undergoing general anaesthesia for hypopharyngeal or laryngotracheal surgery. This was achieved through continuous delivery of transnasal high-flow humidified oxygen, initially to provide pre-oxygenation, and continuing as post-oxygenation during intravenous induction of anaesthesia and neuromuscular blockade until a definitive airway was secured. Apnoea time commenced at administration of neuromuscular blockade and ended with commencement of jet ventilation, positive-pressure ventilation or recommencement of spontaneous ventilation. During this time, upper airway patency was maintained with jaw-thrust. Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) was used in 15 males and 10 females. Mean (SD [range]) age at treatment was 49 (15 [25–81]) years. The median (IQR [range]) Mallampati grade was 3 (2–3 [2–4]) and direct laryngoscopy grade was 3 (3–3 [2–4]). There were 12 obese patients and nine patients were stridulous. The median (IQR [range]) apnoea time was 14 (9–19 [5–65]) min. No patient experienced arterial desaturation < 90%. Mean (SD [range]) post-apnoea end-tidal (and in four patients, arterial) carbon dioxide level was 7.8 (2.4 [4.9–15.3]) kPa. The rate of increase in end-tidal carbon dioxide was 0.15 kPa.min−1. We conclude that THRIVE combines the benefits of ‘classical’ apnoeic oxygenation with continuous positive airway pressure and gaseous exchange through flow-dependent deadspace flushing. It has the potential to transform the practice of anaesthesia by changing the nature of securing a definitive airway in emergency and difficult intubations from a pressured stop–start process to a smooth and unhurried undertaking.

https://emcrit.org/wp-content/uploads/2011/10/Thrive.pdf

Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE): a physiological method of increasing apnoea time in patients with difficult airways

High-flow nasal cannula (HFNC) oxygen therapy is carried out using an air/oxygen blender, active humidifier, single heated tube, and nasal cannula. Able to deliver adequately heated and humidified medical gas at flows up to 60 L/min, it is considered to have a number of physiological advantages compared with other standard oxygen therapies, including reduced anatomical dead space, PEEP, constant F(IO2), and good humidification. Although few large randomized clinical trials have been performed, HFNC has been gaining attention as an alternative respiratory support for critically ill patients. Published data are mostly available for neonates. For critically ill adults, however, evidence is uneven because the reports cover various subjects with diverse underlying conditions, such as hypoxemic respiratory failure, exacerbation of COPD, postextubation, preintubation oxygenation, sleep apnea, acute heart failure, and conditions entailing do-not-intubate orders. Even so, across the diversity, many published reports suggest that HFNC decreases breathing frequency and work of breathing and reduces the need for respiratory support escalation. Some important issues remain to be resolved, such as definitive indications for HFNC and criteria for timing the starting and stopping of HFNC and for escalating treatment. Despite these issues, HFNC has emerged as an innovative and effective modality for early treatment of adults with respiratory failure with diverse underlying diseases.

http://rc.rcjournal.com/content/respcare/61/4/529.full.pdf

High-Flow Nasal Cannula Oxygen Therapy in Adults: Physiological Benefits, Indication, Clinical Benefits, and Adverse Effects

Recent studies showed that nasal high flow (NHF) with or without supplemental oxygen can assist ventilation of patients with chronic respiratory and sleep disorders. The hypothesis of this study was to test whether NHF can clear dead space in two different models of the upper nasal airways. The first was a simple tube model consisting of a nozzle to simulate the nasal valve area, connected to a cylindrical tube to simulate the nasal cavity. The second was a more complex anatomically representative upper airway model, constructed from segmented CT-scan images of a healthy volunteer. After filling the models with tracer gases, NHF was delivered at rates of 15, 30, and 45 l/min. The tracer gas clearance was determined using dynamic infrared CO2 spectroscopy and 81mKr-gas radioactive gamma camera imaging. There was a similar tracer-gas clearance characteristic in the tube model and the upper airway model: clearance half-times were below 1.0 s and decreased with increasing NHF rates. For both models, the anterior compartments demonstrated faster clearance levels (half-times < 0.5 s) and the posterior sections showed slower clearance (half-times < 1.0 s). Both imaging methods showed similar flow-dependent tracer-gas clearance in the models. For the anatomically based model, there was complete tracer-gas removal from the nasal cavities within 1.0 s. The level of clearance in the nasal cavities increased by 1.8 ml/s for every 1.0 l/min increase in the rate of NHF. The study has demonstrated the fast-occurring clearance of nasal cavities by NHF therapy, which is capable of reducing of dead space rebreathing.

Nasal high flow clears anatomical dead space in upper airway models

Background High-flow nasal oxygen (HFNO) has been shown to benefit oxygenation, ventilation and upper airway patency in a range of clinical scenarios, however its use in spontaneously breathing patients during general anaesthesia has not been described. Spontaneous respiration using i.v. anaesthesia is the primary technique used at our institution for tubeless airway surgery. We hypothesized that the addition of HFNO would increase our margin of safety, particularly during management of an obstructed airway. Methods A retrospective observational study was conducted using a SponTaneous Respiration using IntraVEnous anaesthesia and High-flow nasal oxygen (STRIVE Hi) technique to manage 30 adult patients undergoing elective laryngotracheal surgery. Results Twenty-six patients (87%) presented with significant airway and/or respiratory compromise (16 were stridulous, 10 were dyspnoeic). No episodes of apnoea or complete airway obstruction occurred during the induction of anaesthesia using STRIVE Hi. The median [IQR (range)] lowest oxygen saturation during the induction period was 100 [99–100 (97–100)] %. The median [IQR (range)] overall duration of spontaneous ventilation was 44 [40–49.5 (18–100)] min. The median [IQR (range)] end-tidal carbon dioxide (ETCO2) level at the end of the spontaneous ventilation period was 6.8 [6.4–7.1 (4.8–8.9)] kPa. The mean rate of increase in ETCO2 was 0.03 kPa min−1. Conclusions STRIVE Hi succeeded in preserving adequate oxygen saturation, end-tidal carbon dioxide and airway patency. We suggest that the upper and lower airway benefits attributed to HFNO, are ideally suited to a spontaneous respiration induction, increasing its margin of safety. STRIVE Hi is a modern alternative to the traditional inhalation induction.

SponTaneous Respiration using IntraVEnous anaesthesia and Hi-flow nasal oxygen (STRIVE Hi) maintains oxygenation and airway patency during management of the obstructed airway: an observational study

Background
High-flow nasal cannula (HFNC) oxygen therapy in acute hypoxic respiratory failure is becoming increasingly popular. However, evidence to support the use of HFNC in acute respiratory failure (ARF) with hypercapnia is limited.

/pdf/high-flow-nasal-cannula-oxygen-therapy-versus-non-invasive-3hlb0doqhl.pdf

High flow nasal cannula oxygen therapy versus non-invasive ventilation for chronic obstructive pulmonary disease with acute-moderate hypercapnic respiratory failure: an observational cohort study.

Hypercarbic respiratory failure, occurring secondary to chronic lung disease, is a frequently encountered problem. These patients present a significant challenge to respiratory and critical care services, as many are unsuitable for mechanical ventilation and most have multiple comorbidities. Recently, noninvasive ventilation (NIV) has become established as the primary modality for respiratory support in this group of patients. Several factors limit patient compliance with NIV, not least comfort and tolerability. A recent innovation in adult critical care is the use of high-flow nasal oxygen (HFNO) devices. These systems are capable of delivering high gas flows via nasal cannulae, with the ability to blend air and oxygen to give a controlled FiO2. Few clinical studies have been conducted in adults, although several are planned. To date the majority of available evidence addresses the use of HFNO in hypoxemic respiratory failure. Here we present a case in which a HFNO system was used to successfully manage hypercarbic respiratory failure in a patient unable to tolerate conventional NIV.

https://journals.sagepub.com/doi/pdf/10.1177/1753465814521890

The use of high-flow nasal oxygen therapy in the management of hypercarbic respiratory failure:

Vascular involvement in Systemic Sclerosis (SSc) is known to start even before clinical diagnosis, to drive Digital Ulcer disease and later in the disease natural history to cause Pulmonary Artery Hypertension, among other manifestations. Despite the proven immune origin of Scleroderma, vascular involvement is not currently targeted by immune driven interventions. Similarly, little data is available on immune or inflammatory biomarkers and outcome measures of vascular disease in SSc. Digital Artery Volume Index (DAVIX) has been recently proposed as imaging surrogate outcome measure of vascular disease activity in SSc [1].Here we aimed to determine the value of DAVIX as overall biomarker of vascular involvement and its correlation with Type I IFN activation in patients with SSc.Eighty-six patients attending our Scleroderma Program were consecutively enrolled for the evaluation of serum IFN score as previously described [2]. Clinical features including presence or history of Digital Ulcers, Presence of Pulmonary Artery Hypertension (PAH) and DLCO, were recorded. Digital Artery Vascular Index (DAVIX) of the dominant hand’s fingers was calculated using time of flight magnetic resonance images analysed through IAG proprietary algorithm, as previously described [1]. Medians were compared by Mann-Whitney-Wilcoxon test, correlation with clinical parameters was performed using Spearman’s or Pearson test, as appropriate (R).Sixty-two patients fulfilled the 2013 ACR/EULAR classification criteria for SSc (diffuse cutaneous 24.6%, limited cutaneous 75.4%) whereas 23 were classified as Very Early Diagnosis of Scleroderma (Criteria score between 6 and 8). Twenty-three patients had DU disease (History of DUs in the previous 24 weeks, presence of DUs at baseline assessment, or onset of new DUs during the following 24 weeks). Eighteen patients had reduced DLCO (<70) with FVC/DLCO>1.8 (suspected PAH). DAVIX showed a negative correlation with disease duration (r=-0.33 and p=.003) and with FVC/DLCO ratio (r=-0.34 and p=.009). Patients with DU disease presented lower DAVIX than patients without (p=.018).DAVIX showed a significant correlation with Serum IFN score (r=-0.24, p<0.032). Accordingly, patients classified as IFN-HI had lower DAVIX than those within the IFN-LO group (p=0.016).DAVIX correlated both with presence of Digital Ulcer disease, DLCO and disease duration. The correlation of DAVIX and Serum IFN score does support the notion of innate immune involvement in vascular disease manifestations of SSc. Prospective testing in the context of Randomised controlled trial will determine the value of DAVIX as surrogate outcome measure of vascular disease severity in SSc.[1]Gjeloshi K, et al. Arthritis Rheumatol. 2020.[2]Hinchcliff M et al. Arthritis Rheumatol. 2021.Stefano Di Donato: None declared, Mike Hughes: None declared, Giuseppina Abignano: None declared, Giovanni Lettieri: None declared, Rebecca Ross: None declared, Enrico De Lorenzis: None declared, Philip O’Connor: None declared, Olga Kubassova Shareholder of: IAG Image Analysis Group, CEO, Francesco Del Galdo: None declared

/pdf/ab0142-evidence-of-type-i-interferon-activation-during-2p0pw5vm.pdf

Ab0142 evidence of type i interferon activation during vascular manifestations of systemic sclerosis

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Philip O’Connor

Author Tools

Chat about Author

Papers

The use of high-flow nasal oxygen therapy in the management of hypercarbic respiratory failure:

Ab0142 evidence of type i interferon activation during vascular manifestations of systemic sclerosis