High-flow Nasal Therapy Research Articles

Authors’ Responses to Peer Reviews of “Utility of the ROX Index in Predicting Intubation for Patients With COVID-19–Related Hypoxemic Respiratory Failure Receiving High-Flow Nasal Therapy: Retrospective Cohort Study”

Authors’ Responses to Peer Reviews of “Utility of the ROX Index in Predicting Intubation for Patients With COVID-19–Related Hypoxemic Respiratory Failure Receiving High-Flow Nasal Therapy: Retrospective Cohort Study”

Peer Review of “Utility of the ROX Index in Predicting Intubation for Patients With COVID-19–Related Hypoxemic Respiratory Failure Receiving High-Flow Nasal Therapy: Retrospective Cohort Study”

Peer Review of “Utility of the ROX Index in Predicting Intubation for Patients With COVID-19–Related Hypoxemic Respiratory Failure Receiving High-Flow Nasal Therapy: Retrospective Cohort Study”

Peer Review of “Utility of the ROX Index in Predicting Intubation for Patients With COVID-19–Related Hypoxemic Respiratory Failure Receiving High-Flow Nasal Therapy: Retrospective Cohort Study”

Peer Review of “Utility of the ROX Index in Predicting Intubation for Patients With COVID-19–Related Hypoxemic Respiratory Failure Receiving High-Flow Nasal Therapy: Retrospective Cohort Study”

What Helps Us Decide to Adopt an Intervention: Efficacy, Costs, or Both?

What Helps Us Decide to Adopt an Intervention: Efficacy, Costs, or Both?

Nasal High-Flow for Weaning Preterm Newborns with Risk of Chronic Lung Disease from nCPAP.

The aim of the study is to compare the duration of oxygen therapy by using two methods of weaning from nasal continuous positive airway pressure (nCPAP) in very preterm babies. Between April 2014 and December 2016, 90 preterm <32 weeks and birthweight >1,000 g who, after at least 7 days on nCPAP, were clinically stable on <6 cm H2O and FiO2 <30% were randomly assigned to weaning directly from nCPAP or with nasal high flow therapy (nHFT). In the nCPAP group, pressure was gradually reduced until the infant was stable on 4 cm H2O and then discontinued. In the nHFT group, flow rate was reduced until the infant was stable at 3.l pm and then discontinued. Eighty-four infants completed the study. There were no differences between the groups for the primary outcome, duration of oxygen therapy (median 33 [14-48] versus 28 [15-37] days; p = 0.17). The incidence of moderate-to-severe bronchopulmonary dysplasia was similar. Weaning time was shorter in the nCPAP group (p = 0.02), but the failure rate was slightly higher although non-significant. In the nHFT group, we observed better perception of patient comfort and a lower incidence of severe nasal injury. Weaning by nHFT compared with weaning directly off nCPAP does not prolong duration of oxygen therapy. Rather, it is associated with better perceptions of infant comfort among parents and lower rates of severe nasal injury. · Nasal high-flow therapy is commonly used in most neonatal intensive care unit for nCPAP weaning.. · Weaning by nHFT does not increase the duration of oxygen therapy.. · nHFT use improves the perception of infant comfort among parents..

Remdesivir en pacientes trasplantados renales con neumonía por SARS-CoV-2

BackgroundRemdesivir is the only antiviral treatment that has been shown to be useful against SARS-CoV-2 infection. It shorts hospitalization time compared to placebo. Its effects in kidney transplant (KT) patients are limited to some published cases. MethodsWe performed a retrospective observational study that included all KT patients admitted between August 1st, 2020 and December 31st, 2020 with SARS-CoV-2 pneumonia who received remdesivir.The objective of this study was to describe the experience of a cohort of KT patients treated with remdesivir. DiscussionA total of 37 KT patients developed SARS-CoV-2 infection, 7 of them received treatment with remdesivir. The rest of the patients did not receive the drug due to either CKD-EPI less than 30mL/min or they did not present clinical criteria. In addition to remdesivir, all patients received dexamethasone and anticoagulation therapy. 4 were men, the median age was 59 (53–71) years. Median time from transplantation was 43 (16–82) months. Chest X-rays of all patients showed pulmonary infiltrates and required low-oxygen flow therapy upon admission, requiring high-flow nasal therapy in 3 cases. Only 2 cases presented deterioration of the graft function, not requiring hemodialysis in any case, and all recovered renal function at hospital discharge. 2 patients rise up 1.5 times the liver function test. No patient died or required admission to the critical care unit. Median days of admission was 12 (9–27) days. ConclusionsOur study suggests that the use of remdesivir could be useful in KT patients with SARS-CoV-2 pneumonia without side effects. Additional studies are necessary with a larger number of patients to improve the knowledge of this drug in SARS-CoV-2 infection.

Persistent Pulmonary Atelectasis in Patient with Rheumatoid Arthritis Treated with High-Flow Therapy and High-Frequency Chest Wall Oscillation

Rheumatoid arthritis is a systemic inflammatory disorder that affects ∼1-2% of the population. Although a progressive destruction of cartilage and bone is the main presentation, extra-articular manifestations can occur in about 40% of patients during the course of their disease and are associated with significant morbidity and increased mortality. Pulmonary complications can frequently occur in these patients, although not always clinically recognized. We present a case of 60-year-old woman suffering from rheumatoid arthritis came to our department for the presence of exertional dyspnea, cough with poor mucous expectoration, chest pain and worsening of daytime asthenia. At a chest x-ray, evidence of right basal pulmonary atelectasis, for which she had practiced antibiotic therapy with persistence of symptomatology and pulmonary atelectasis. Chest CT showed parenchymal consolidation. The patient was treated with antibiotics and rehabilitation therapy, bronchial endoscopy, with persistence of pulmonary atelectasis. She started nasal high-flow therapy but in the seventh day appears epistaxis. For this reason, she suspended treatment with NHF. At the next rehabilitation session, for the recurrence of epistaxis, an otorhinolaryngology visit was performed that confirms the presence of nasal varices. Therefore, the patient started high-flow therapy with a mouthpiece with the use of High Frequency Chest Wall Oscillation. At the end of rehabilitative treatment we observed clinical and radiological improvement.

High flow nasal oxygen for acute type two respiratory failure: a systematic review

Background: Acute type two respiratory failure (AT2RF) is characterized by high carbon dioxide levels (PaCO 2 >6kPa). Non-invasive ventilation (NIV), the current standard of care, has a high failure rate. High flow nasal therapy (HFNT) has potential additional benefits such as CO 2 clearance, the ability to communicate and comfort. The primary aim of this systematic review is to determine whether HFNT in AT2RF improves 1) PaCO 2, 2) clinical and patient-centred outcomes and 3) to assess potential harms. Methods: We searched EMBASE, MEDLINE and CENTRAL (January 1999-January 2021). Randomised controlled trials (RCTs) and cohort studies comparing HFNT with low flow nasal oxygen (LFO) or NIV were included. Two authors independently assessed studies for eligibility, data extraction and risk of bias. We used Cochrane risk of bias tool for RCTs and Ottawa-Newcastle scale for cohort studies. Results: From 727 publications reviewed, four RCTs and one cohort study (n=425) were included. In three trials of HFNT vs NIV, comparing PaCO 2 (kPa) at last follow-up time point, there was a significant reduction at four hours(1 RCT; HFNT median 6.7, IQR 5.6 - 7.7 vs NIV median 7.6, IQR 6.3 - 9.3) and no significant difference at 24-hours or five days. Comparing HFNT with LFO, there was no significant difference at 30-minutes. There was no difference in intubation or mortality. Conclusions: This review identified a small number of studies with low to very low certainty of evidence. A reduction of PaCO 2 at an early time point of four hours post-intervention was demonstrated in one small RCT. Significant limitations of the included studies were lack of adequately powered outcomes and clinically relevant time-points and small sample size. Accordingly, systematic review cannot recommend the use of HFNT as the initial management strategy for AT2RF and trials adequately powered to detect clinical and patient-relevant outcomes are urgently warranted.

Analysis of the effect of sequential high-flow nasal canula oxygen therapy in post-extubation mechanically ventilated patients in intensive care unit

To observe the application effect of high-flow nasal canula oxygen therapy (HFNC) after extubation in patients with mechanical ventilation (MV) in the intensive care unit (ICU). A prospective study was conducted. From January 2018 to June 2020, 163 MV patients admitted to Yijishan Hospital of Wannan Medical College were enrolled, and they were divided into HFNC group (82 cases) and traditional oxygen therapy group (81 cases) according to the oxygen therapy model. The patients included in the study were given conventional treatment according to their condition. In the HFNC group, oxygen was inhaled by a nasal high-flow humidification therapy instrument. The gas flow was gradually increased from 35 L/min to 60 L/min according to the patient's tolerance, and the temperature was set at 34-37 centigrade. The fraction of inspiration oxygen (FiO2) was set according to the patient's pulse oxygen saturation (SpO2) and SpO2 was maintained at 0.95-0.98. A disposable oxygen mask or nasal cannula was used to inhale oxygen in the traditional oxygen therapy group, and the oxygen flow was 5-8 L/min, maintaining the patient's SpO2 at 0.95-0.98. The differences in MV duration before extubation, total MV duration, intubation time, reintubation time, extubation failure rate, ICU mortality, ICU stay, and in-hospital stay were compared between the two groups, and weaning failure were analyzed. There was no significant differences in MV duration before extubation (days: 4.33±3.83 vs. 4.15±3.03), tracheal intubation duration (days: 4.34±1.87 vs. 4.20±3.35), ICU mortality [4.9% (4/82) vs. 3.7% (3/81)] and in-hospital stay [days: 28.93 (15.00, 32.00) vs. 27.69 (15.00, 38.00)] between HFNC group and traditional oxygen therapy group (all P > 0.05). The total MV duration in the HFNC group (days: 4.48±2.43 vs. 5.67±3.84) and ICU stay [days: 6.57 (4.00, 7.00) vs. 7.74 (5.00, 9.00)] were significantly shorter than those in the traditional oxygen therapy group, the reintubation duration of the HFNC group was significantly longer than that of the traditional oxygen therapy group (hours: 35.75±10.15 vs. 19.92±13.12), and the weaning failure rate was significantly lower than that of the traditional oxygen therapy group [4.9% (4/82) vs. 16.0% (13/81), all P < 0.05]. Among the reasons for weaning failure traditional oxygen therapy group had lower ability of airway secretion clearance than that of the HFNC group [8.64% (7/81) vs. 0% (0/82), P < 0.05], there was no statistically differences in the morbidity of heart failure, respiratory muscle weakness, hypoxemia, and change of consciousness between the two groups. For MV patients in the ICU, the sequential application of HFNC after extubation can reduce the rate of weaning failure and the incidence of adverse events, shorten the length of ICU stay.

MO991KIDNEY TRANSPLANT PATIENTS INFECTED BY SARS-COV-2 PNEUMONIA TREATED WITH REMDESIVIR: CASES REPORTS

Background and AimsRemdesivir is the only treatment that has been shown to be useful against SARS-CoV-2 infection. It shorts hospitalization time compared to placebo. Kidney transplant (KT) patients were not included in these studies, therefore, its effects in this population is limited to some published cases.MethodWe performed a retrospective observational study that included all KT patients admitted between August 01, 2020 and November 17, 2020 with SARS-CoV-2 pneumonia who received treatment with remdesivir. Patients received a 200mg loading dose followed by 100 mg/day maintenance dose for 5 days. The objective of this study was to describe the experience of a cohort of KT patients treated with remdesivir.ResultsA total of 36 KT patients developed SARS-CoV-2 infection, 6 of them received treatment with remdesivir. The rest of the patients did not receive the drug due to either CKD-EPI less than 30 mL/min or they did not present clinical criteria. In addition to remdesivir, all pacients received dexamethasone and anticoagulation therapy. Immunosuppression was suspended in all patients, maintaining only dexamethasone. 50% were men, the median age was 58.5 (52.75–68) years. 67% had unknown underlying kidney disease, 83% were hypertensive and 33% had diabetes. All patients received KT from deceased brain donor and 50% received thymoglobulin as induction treatment. Median time from transplantation was 49 (20.5–135.5) months, with median glomerular filtration at admission of 47.5 (42.25–63.25) mL/min. The most frequent clinical manifestation was dry cough and dyspnea (83%), followed by tachypnea and fever (67%). Chest X-rays of all patients showed pulmonary infiltrates and required low oxygen flow therapy upon admission, requiring high flow nasal therapy in 33% of cases during admission. Only 17% of the cases presented deterioration of the graft function, not requiring hemodialysis in any case, and all recovered renal function at hospital discharge. No patient died or required admission to the critical care unit. Median days of admission was 12 (10–18) days.ConclusionKT patients with SARS-CoV-2 pneumonia under treatment with remdesivir have a good clinical course, with few cases of renal function deterioration and a low mortality rate. Additional studies are necessary with a larger number of patients to improve the knowledge of remdesivir in KT with SARS-CoV-2 infection.

High flow nasal therapy in the management of hypoxemic dyspnea at the end of life

Refractory dyspnea is challenging for physicians treating patients near to the end of life. High-flow nasal therapy (HFNT). We report a case in which HFNS was effective in a patient in the last days of life to mitigate dyspnea allowing a minimal quality of life for some days before dying. HFNT may be helpful for severely hypoxemic patients who are unresponsive to common measured adopted in the last weeks–days of life of advanced cancer patients. Future studies should assess an early use of this device in combination with lower doses of opioids or as an alternative.

Randomised controlled trial of oxygen therapy and high-flow nasal therapy in African children with pneumonia

PurposeThe life-saving role of oxygen therapy in African children with severe pneumonia is not yet established.MethodsThe open-label fractional-factorial COAST trial randomised eligible Ugandan and Kenyan children aged > 28 days with severe pneumonia and severe hypoxaemia stratum (SpO2 < 80%) to high-flow nasal therapy (HFNT) or low-flow oxygen (LFO: standard care) and hypoxaemia stratum (SpO2 80–91%) to HFNT or LFO (liberal strategies) or permissive hypoxaemia (ratio 1:1:2). Children with cyanotic heart disease, chronic lung disease or > 3 h receipt of oxygen were excluded. The primary endpoint was 48 h mortality; secondary endpoints included mortality or neurocognitive sequelae at 28 days.ResultsThe trial was stopped early after enrolling 1852/4200 children, including 388 in the severe hypoxaemia stratum (median 7 months; median SpO2 75%) randomised to HFNT (n = 194) or LFO (n = 194) and 1454 in the hypoxaemia stratum (median 9 months; median SpO2 88%) randomised to HFNT (n = 363) vs LFO (n = 364) vs permissive hypoxaemia (n = 727). Per-protocol 15% of patients in the permissive hypoxaemia group received oxygen (when SpO2 < 80%). In the severe hypoxaemia stratum, 48-h mortality was 9.3% for HFNT vs. 13.4% for LFO groups. In the hypoxaemia stratum, 48-h mortality was 1.1% for HFNT vs. 2.5% LFO and 1.4% for permissive hypoxaemia. In the hypoxaemia stratum, adjusted odds ratio for 48-h mortality in liberal vs permissive comparison was 1.16 (0.49–2.74; p = 0.73); HFNT vs LFO comparison was 0.60 (0.33–1.06; p = 0.08). Strata-specific 28 day mortality rates were, respectively: 18.6, 23.4 and 3.3, 4.1, 3.9%. Neurocognitive sequelae were rare.ConclusionsRespiratory support with HFNT showing potential benefit should prompt further trials.

Evaluation of Aerosol Therapy during the Escalation of Care in a Model of Adult Cystic Fibrosis.

Lung disease is the main cause of morbidity and mortality in cystic fibrosis (CF). CF patients inhale antibiotics regularly as treatment against persistent bacterial infections. The goal of this study was to investigate the effect of clinical intervention on aerosol therapy during the escalation of care using a bench model of adult CF. Droplet size analysis of selected antibiotics was completed in tandem with the delivered aerosol dose (% of total dose) assessments in simulations of various interventions providing oxygen supplementation or ventilatory support. Results highlight the variability of aerosolised dose delivery. In the homecare setting, the vibrating mesh nebuliser (VMN) delivered significantly more than the jet nebuliser (JN) (16.15 ± 0.86% versus 6.51 ± 2.15%). In the hospital setting, using VMN only, significant variability was seen across clinical interventions. In the emergency department, VMN plus mouthpiece (no supplemental oxygen) was seen to deliver (29.02 ± 1.41%) versus low flow nasal therapy (10 L per minute (LPM) oxygen) (1.81 ± 0.47%) and high flow nasal therapy (50 LPM oxygen) (3.36 ± 0.34%). In the ward/intensive care unit, non-invasive ventilation recorded 19.02 ± 0.28%, versus 22.64 ± 1.88% of the dose delivered during invasive mechanical ventilation. These results will have application in the design of intervention-appropriate aerosol therapy strategies and will be of use to researchers developing new therapeutics for application in cystic fibrosis and beyond.

Exhalation Spreading During Nasal High-Flow Therapy at Different Flow Rates.

Severe acute respiratory syndrome coronavirus 2 is transmitted through aerosols and droplets. Nasal high-flow therapy could possibly increase the spreading of exhalates from patients. The aim of this study is to investigate whether nasal high-flow therapy affects the range of the expiratory plume compared with spontaneous breathing. Interventional experiment on single breaths of a healthy volunteer. Research laboratory at the Bauhaus-University Weimar. A male subject. Videos and images from a schlieren optical system were analyzed during spontaneous breathing and different nasal high-flow rates. The maximal exhalation spread was 0.99, 2.18, 2.92, and 4.1 m during spontaneous breathing, nasal high-flow of 20 L/min, nasal high-flow of 40 L/min, and nasal high-flow of 60 L/min, respectively. Spreading of the expiratory plume in the sagittal plane can completely be blocked with a surgical mask. Nasal high-flow therapy increases the range of the expiratory air up to more than 4 meters. The risk to pick up infectious particles could be increased within this range. Attachment of a surgical mask over the nasal high-flow cannula blocks the expiratory airstream.

Nasal high-flow therapy as an adjunct to exercise in patients with cystic fibrosis: A pilot feasibility trial

BackgroundExercise tolerance in people with CF and advanced lung disease is often reduced. While supplemental oxygen can improve oxygenation, it does not affect dyspnoea, fatigue or comfort. Nasal high-flow therapy (NHFT), thanks to its pathophysiological mechanisms, could improve exercise tolerance, saturation and dyspnoea. This study explores the feasibility of conducting a clinical trial of using NHFT in patients with CF during exercise. MethodsA pilot, open-label, randomized crossover trial was performed, enroling 23 participants with CF and severe lung disease. Participants completed two treadmill walking test (TWT) with and without NHFT at 24–48 h interval. Primary outcome was trial feasibility, and exploratory outcomes were TWT distance (TWTD), SpO2, transcutaneous CO2, dyspnoea and comfort. ResultsRecruitment rate was 2.4 subjects/month with 1.3:1 screening-to-randomization ratio. No adverse events caused by NHFT were observed. Tolerability was good and data completion rate was 100%. Twenty subjects (91%) were included in the exploratory study. Mean difference in TWTD on NHFT was 19 m (95% CI [4.8 - 33.1]). SpO2 was similar, but respiratory rate and mean tcCO2 were lower on NHFT (mean difference = -3.9 breaths/min 95% CI [-5.9 - -1.9] and -0.22 kPa 95% CI [-0.4 – 0.04]). NHFT reduced exercise-induced dyspnoea and discomfort. ConclusionTrials using NHFT in patients with CF during exercise are feasible. NHFT appears to improve walking distance, control respiratory rate, CO2, dyspnoea and improve comfort. A larger trial with a longer intervention is feasible and warranted to confirm the impact of NHFT in training programmes for patients with CF.

Fugitive aerosols in the intensive care unit: a narrative review.

The risk of unintended inhalation of fugitive aerosols is becoming a topic of increasing interest in the healthcare arena. These fugitive aerosols may be bioaerosols, generated by the patient themselves through cough or sneeze, or they may be therapeutic medical aerosols, generated by therapeutic medical aerosol generators with the intent of delivery to a specific patient's respiratory tract. This review focus' on therapeutic aerosols in the intensive care unit (ICU) only, those typically generated by nebulisers. In the intensive care environment, patients are generally in receipt of ventilatory support, and the literature suggests that these different support interventions influence fugitive therapeutic medical aerosol emissions in a variety of ways. Predominant ventilatory support interventions include, but are not limited to, invasive mechanical ventilation (MV), non-invasive mechanical ventilation (NIV), high flow nasal therapy (HFNT), and supplemental oxygen delivery in spontaneously breathing patients. Further, factors such as nebuliser type, patient interface, patient breathing pattern, nebuliser position in the patient breathing circuit and medication formulation characteristics also have been shown to exert influence on aerosol concentrations and distance from the source. Here we present the state of the art knowledge in this, as yet, poorly described field of research, and identify the key risks, and subsequently, opportunities to mitigate the risks of unintended exposure of both patients and bystanders during and for periods following the administration of therapeutic aerosols.

Pressurized Metered Dose Inhaler Aerosol Delivery Within Nasal High-Flow Circuits: A Bench Study.

Background: Obstructive patients may benefit from nasal high-flow (NHF) therapy, but the use of pressurized metered-dose inhalers (pMDIs) has not been evaluated in this situation. Methods: Using an adult circuit and medium-sized cannula, we have tested different NHF rates, pMDI positions, breathing patterns, spacers, and spacer orientation. First, we evaluated albuterol delivery at the nasal cannula outlet. The second set of experiments made use of a nasopharyngeal cast to estimate the mass of albuterol potentially reaching the lungs. Albuterol was caught on filters placed at the cannula outlet and downstream of the nasal cast, and albuterol was quantified by spectrophotometry. Results: The highest amounts of albuterol delivered at the cannula outlet were observed with a 30 L/min flow rate (vs. 45 and 60 L/min) and placing the device close to the nasal cannula (in comparison with a position on the dry side of the humidification chamber). The use of a spacer was associated with higher delivery. The highest albuterol delivery was observed placing the spacer close to the nasal cannula, oriented for aerosol delivery following the gas flow and a 30 L/min NHF rate. Using this optimal setting, activating the pMDI at the beginning of inspiration (compared to expiration) increased albuterol delivery downstream of the nasopharyngeal cast. Whether in a quiet- or distress-breathing pattern, our measurements showed an amount of albuterol potentially delivered to the lungs exceeding 10% of the actuated dose in optimal conditions. Conclusions: Albuterol delivery with pMDIs is feasible within NHF circuits. Drug delivery sufficient to induce bronchodilation can be achieved using a spacer placed just upstream of the nasal cannula, a low NHF rate, and activation of the pMDI at the beginning of inspiration. Further testing in a clinical setting is required, however.

Nasal high flow therapy in heart failure patients with central sleep apnea: a report of disproportional occurrence of cardiac arrhythmias

Nasal high flow therapy in heart failure patients with central sleep apnea: a report of disproportional occurrence of cardiac arrhythmias

High-flow nasal cannula therapy for initial oxygen administration in acute hypercapnic respiratory failure: study protocol of randomised controlled unblinded trial

IntroductionAcute respiratory failure is a common clinical condition accounting for nearly 116 000 admissions in the UK hospitals. Acute type 2 respiratory failure is also called acute hypercapnic respiratory failure...

The Effect of Nasal High Flow Therapy on Minute Ventilation in Chronic Obstructive Pulmonary Disease.

Nasal high-flow therapy (HFT) has been shown to improve daytime breathing mechanics in healthy adults as well as the lung function and quality of life in chronic obstructive pulmonary disease (COPD) patients. We hypothesized that improved breathing mechanics with HFT may further reduce minute ventilation (i.e. decreased work of breathing) during sleep in patients with COPD. In COPD participants we examined the dose effect of HFT (within night randomization of HFT level; 0, 10, 20 and 30L/min) on minute ventilation, oxyhemaglobin saturation and transcutaneous carbon dioxide during wake and sleep. We assessed overnight polysomnography with and without HFT on two separate nights. Paired t-tests were used to compare overnight sleep quality with and without HFT. The association between ventilatory variables and HFT level was assessed using regression analysis. During sleep, HFT decreased minute ventilation by 0.63±0.02L/min per 10L/min nasal airflow by reducing tidal volume (37±6mL per 10L/min; p<0.001) without affecting respiratory rate (p=0.9) or arterial CO2 (p=0.7). In contrast, during wakefulness reductions in minute ventilation (0.85±0.04L/min per 10L/min) was due to respiratory rate reduction along with prolongation in expiratory time. The reduction in minute ventilation is greater with higher dead-space volumes (r=0.50; p<0.02) and during wakefulness suggesting that ventilatory responses to HFT are mediated through a reduction in dead-space ventilation. The reduction in ventilation in response to HFT is large enough to reduce respiratory loads. Reducing respiratory loads may avert muscle fatigue, preserve respiratory function, or prevent development of respiratory failure.