The application of a surgical face mask over different oxygen delivery devices; a crossover study of measured end-tidal oxygen concentrations.

BACKGROUND: The application of a surgical face mask over oxygen delivery devices is now a widespread recommendation in the setting of the Coronavirus disease pandemic. This addition is designed to reduce droplet spread, but this also changes the nature of these devices, and may alter the amount of oxygen delivered to a patient. This research investigated how placing a surgical face mask over both a simple plastic mask ("Hudson mask") and nasal cannula altered the concentration of available oxygen measured at the nares. METHODS: We measured the inspired and end-tidal oxygen concentrations of five healthy non-smoking volunteers. Oxygen was delivered via nasal cannula and also a simple plastic face mask, at flow rates of 2, 4, 6 and 8 l per minute, with and without an overlying surgical face mask. RESULTS: Adding a surgical mask over nasal cannula caused an appreciable rise in the end-tidal oxygen concentrations at all the measured oxygen flow rates 2, 4, 6, 8 L/minute. With the Hudson mask, there was a rise in oxygen concentration at 4 and 6 L/minute. For example, at a flow rate of 4 l/min via nasal cannula, available oxygen concentration increased from 24 to 36%, and via the Hudson mask the concentration rose from 27 to 38%. CONCLUSIONS: The addition of a surgical face mask over both nasal cannula and a Hudson mask resulted in an increased available oxygen concentration. This may be valuable where more advanced oxygen devices are not available, or alternatively providing adequate supplemental oxygen at lower flow rates and thus making critical savings in oxygen usage.

Effect of High-Flow Oxygen Therapy vs Conventional Oxygen Therapy on Invasive Mechanical Ventilation and Clinical Recovery in Patients With Severe COVID-19: A Randomized Clinical Trial.

IMPORTANCE: The effect of high-flow oxygen therapy vs conventional oxygen therapy has not been established in the setting of severe COVID-19. OBJECTIVE: To determine the effect of high-flow oxygen therapy through a nasal cannula compared with conventional oxygen therapy on need for endotracheal intubation and clinical recovery in severe COVID-19. DESIGN, SETTING, AND PARTICIPANTS: Randomized, open-label clinical trial conducted in emergency and intensive care units in 3 hospitals in Colombia. A total of 220 adults with respiratory distress and a ratio of partial pressure of arterial oxygen to fraction of inspired oxygen of less than 200 due to COVID-19 were randomized from August 2020 to January 2021, with last follow-up on February 10, 2021. INTERVENTIONS: Patients were randomly assigned to receive high-flow oxygen through a nasal cannula (n = 109) or conventional oxygen therapy (n = 111). MAIN OUTCOMES AND MEASURES: The co-primary outcomes were need for intubation and time to clinical recovery until day 28 as assessed by a 7-category ordinal scale (range, 1-7, with higher scores indicating a worse condition). Effects of treatments were calculated with a Cox proportional hazards model adjusted for hypoxemia severity, age, and comorbidities. RESULTS: Among 220 randomized patients, 199 were included in the analysis (median age, 60 years; n = 65 women [32.7%]). Intubation occurred in 34 (34.3%) randomized to high-flow oxygen therapy and in 51 (51.0%) randomized to conventional oxygen therapy (hazard ratio, 0.62; 95% CI, 0.39-0.96; P = .03). The median time to clinical recovery within 28 days was 11 (IQR, 9-14) days in patients randomized to high-flow oxygen therapy vs 14 (IQR, 11-19) days in those randomized to conventional oxygen therapy (hazard ratio, 1.39; 95% CI, 1.00-1.92; P = .047). Suspected bacterial pneumonia occurred in 13 patients (13.1%) randomized to high-flow oxygen and in 17 (17.0%) of those randomized to conventional oxygen therapy, while bacteremia was detected in 7 (7.1%) vs 11 (11.0%), respectively. CONCLUSIONS AND RELEVANCE: Among patients with severe COVID-19, use of high-flow oxygen through a nasal cannula significantly decreased need for mechanical ventilation support and time to clinical recovery compared with conventional low-flow oxygen therapy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04609462.

Respiratory support after delayed cord clamping: a prospective cohort study of at-risk births at ≥35+0 weeks gestation.

OBJECTIVE: To identify risk factors associated with delivery room respiratory support in at-risk infants who are initially vigorous and received delayed cord clamping (DCC). DESIGN: Prospective cohort study. SETTING: Two perinatal centres in Melbourne, Australia. PATIENTS: At-risk infants born at ≥35+0 weeks gestation with a paediatric doctor in attendance who were initially vigorous and received DCC for >60 s. MAIN OUTCOME MEASURES: Delivery room respiratory support defined as facemask positive pressure ventilation, continuous positive airway pressure and/or supplemental oxygen within 10 min of birth. RESULTS: Two hundred and ninety-eight infants born at a median (IQR) gestational age of 39+3 (38+2-40+2) weeks were included. Cord clamping occurred at a median (IQR) of 128 (123-145) s. Forty-four (15%) infants received respiratory support at a median of 214 (IQR 156-326) s after birth. Neonatal unit admission for respiratory distress occurred in 32% of infants receiving delivery room respiratory support vs 1% of infants who did not receive delivery room respiratory support (p<0.001). Risk factors independently associated with delivery room respiratory support were average heart rate (HR) at 90-120 s after birth (determined using three-lead ECG), mode of birth and time to establish regular cries. Decision tree analysis identified that infants at highest risk had an average HR of <165 beats per minute at 90-120 s after birth following caesarean section (risk of 39%). Infants with an average HR of ≥165 beats per minute at 90-120 s after birth were at low risk (5%). CONCLUSIONS: We present a clinical decision pathway for at-risk infants who may benefit from close observation following DCC. Our findings provide a novel perspective of HR beyond the traditional threshold of 100 beats per minute.

Comparison of Actual Performance in the Flow and Fraction of Inspired O2 among Different High-Flow Nasal Cannula Devices: A Bench Study.

Background: High-flow nasal cannula (HFNC) oxygen therapy has been recommended for use in coronavirus disease 2019 (COVID-19) patients with acute respiratory failure and many other clinical conditions. HFNC devices produced by different manufacturers may have varied performance. Whether there is a difference in these devices and the extent of the differences in performance remain unknown. Methods: Four HFNC devices (AIRVO 2, TNI softFlow 50, HUMID-BH, and OH-70C) and a ventilator with an HFNC module (bellavista 1000) were evaluated. The flow was set at 20, 25, 30, 35, 40, 45, 50, 60, 70, and 80 L/min, and the FiO2 was set at 21%, 26%, 30%, 35%, 40%, 45%, 50%, 60%, 70%, 80%, and 90%. Then, one side of the cannulas was clipped to simulate the compression, bending, or blocking of the nasal cannulas. The flow and FiO2 of the delivered gas were recorded and compared among settings and devices. Results: The actual-flow and actual-FiO2 delivered by different settings and devices varied. AIRVO 2 had superior performance in flow and FiO2 accuracy. bellavista 1000 and OH-70C had good performance in the accuracy of actual-flows and actual-FiO2, respectively. bellavista 1000 and HUMID-BH had a larger flow range from 10 to 80 L/min, but only bellavista 1000 could provide a stable flow with an excessive resistance up to 60 L/min. TNI softFlow 50 had the best flow compensation and could provide sufficient flow with excessive resistance at 20-50 L/min. Conclusions: The variation in flow, FiO2 settings, and devices could influence the actual-flow and actual-FiO2 delivered. AIRVO 2 and OH-70C showed better FiO2 accuracy. TNI softFlow 50, bellavista 1000, and HUMID-BH could lower the risk of insufficient flow support due to accidental compression or blocking of the cannulas. In addition, ventilators with HFNC modules provided comparable flow and FiO2 and could be an alternative to standalone HFNC devices.

Course of illness and outcomes in older COVID-19 patients treated with HFNC: a retrospective analysis.

Coronavirus disease-2019 (COVID-19) has rapidly spread worldwide and causes high mortality of elderly patients. High-flow nasal cannula therapy (HFNC) is an oxygen delivery method for severely ill patients. We retrospectively analyzed the course of illness and outcomes in 110 elderly COVID-19 patients (≥65 years) treated with HFNC from 6 hospitals. 38 patients received HFNC (200 mmHg < PaO2/FiO2 ≤ 300 mmHg, early HFNC group), and 72 patients received HFNC (100 mmHg < PaO2/FiO2 ≤ 200 mmHg, late HFNC group). There were no significant differences of sequential organ failure assessment (SOFA) scores and APECH II scores between early and late HFNC group on admission. Compared with the late HFNC group, patients in the early HFNC group had a lower likelihood of developing severe acute respiratory distress syndrome (ARDS), longer time from illness onset to severe ARDS and shorter duration of viral shedding after illness onset, as well as shorter lengths of ICU and hospital stay. 24 patients died during hospitalization, of whom 22 deaths (30.6%) were in the late HFNC group and 2 (5.3%) in the early HFNC group. The present study suggested that the outcomes were better in severely ill elderly patients with COVID-19 receiving early compared to late HFNC.

High flow nasal cannula oxygenation in COVID-19 related acute respiratory distress syndrome: a safe way to avoid endotracheal intubation?

BACKGROUNDS: High flow nasal cannula (HFNC) is an alternative therapy for acute respiratory distress syndrome (ARDS) due to coronavirus disease 2019 (COVID-19). This study aimed first to describe outcomes of patients suffering from COVID-19-related ARDS treated with HFNC; secondly to evaluate safety of HFNC (patients and healthcare workers) and compare patients according to respiratory outcome. METHODS: A retrospective cohort was conducted in French general hospital intensive care unit (ICU). Patients were included if receiving HFNC for hypoxemia (saturation pulse oxygen (SpO2) <92% under oxygen ⩾6 L/min) associated with ARDS and positive SARS-CoV-2 polymerase chain reaction (PCR). Main clinical characteristics and outcomes are described in patients: (a) with do not intubate order (HFNC-DNIO); (b) who did not need intubation (HFNC-only); and (c) eventually intubated (HFNC-intubation). Medians are presented with (1st-3rd) interquartile range. RESULTS: From 26 February to 30 June 2020, 46 patients of median age 75 (70-79) years were included. In the HFNC-DNIO group (n = 11), partial arterial oxygen pressure (PaO2)/inhaled fraction of oxygen (FiO2) ratio median worst PaO2/FiO2 ratio was 109 (102-172) and hospital mortality was 54.5%. Except the HFNC-DNIO patients (n = 35), 20 patients (57%) were eventually intubated (HFNC-intubation group) and 15 were only treated by HFNC (HFNC-only). HFNC-intubation patients presented higher worst respiratory rates per minute in ICU [37 (34-41) versus 33 (24-34) min, p < 0.05] and worsened ICU admission PaO2/FiO2 ratios [121 (103-169) versus 191 (162-219), p < 0.001] compared with HFNC-only patients. Hospital mortality was 35% (n = 7/20) in HFNC-intubation group, 0% in HFNC-only group with a global mortality of these two groups of 20% (n = 7/35). Among tests performed in healthcare workers, 1/12 PCR in symptomatic healthcare workers and 1.8% serologies in asymptomatic healthcare workers were positive. After review of each case, COVID-19 was likely to be acquired outside hospital. CONCLUSIONS: HFNC seems to be useful for COVID-19-related ARDS and safe for healthcare workers. ARDS severity with PaO2/FiO2 <150 associated with respiratory rate >35/min could be regarded as a predictor of intubation.The reviews of this paper are available via the supplemental material section.

Predictors of failure of high flow nasal cannula failure in acute hypoxemic respiratory failure due to COVID-19.

Hypoxemic respiratory failure is a common manifestation of COVID-19 pneumonia. Early in the COVID-19 pandemic, patients with hypoxemic respiratory failure were, at times, being intubated earlier than normal; in part because the options of heated humidified high flow nasal cannula (HFNC) and non-invasive ventilation (NIV) were considered potentially inadequate and to increase risk of virus aerosolization. To understand the benefits and factors that predict success and failure of HFNC in this population, we evaluated data from the first 30 sequential patients admitted with COVID-19 pneumonia to our center who were managed with HFNC. We conducted Cox Proportional Hazards regression models to evaluate the factors associated with high flow nasal cannula failure (outcome variable), using time to intubation (censoring variable), while adjusting for comorbidities and immunosuppression. In the majority of our patients (76.7%), the use of HFNC failed and the patients were ultimately placed on mechanical ventilation. Those at increased risk of failure had a higher sequential organ failure assessment score, and at least one comorbidity or history of immunosuppression. Our data suggest that high flow nasal cannula may have a role in some patients with COVID-19 presenting with hypoxemic respiratory failure, but careful patient selection is the likely key to its success.

[High flow oxygen therapy with nasal cannula: use and applications in respiratory failure in internal medicine.] / Ossigenoterapia ad alti flussi con cannule nasali: razionale di utilizzo e applicazioni nell'insufficienza respiratoria in medicina interna.

High-flow nasal cannula (HFNC) are an oxygen therapy device developed in the last years for the treatment of patients with acute or acute on chronic hypoxemic respiratory failure with different etiology and severity (including covid-19 pneumonia). HFNC combine the possibility of delivering high flows of gases, actively humidified and heated, with the use of a comfortable nasal interface, resulting generally well tolerated by most patients. In light of these characteristics, together with the simplicity of use and versatility, they have spread not only in intensive and semi-intensive care units but also in general medical ward in which they can play an important role in the treatment of elderly, frail patients with comorbidity where other more aggressive and invasive methods of ventilations are not indicated or not practicable.

AEG-SEED position paper for the resumption of endoscopic activity after the peak phase of the COVID-19 pandemic. / Documento de posicionamiento AEG-SEED para el reinicio de la actividad endoscópica tras la fase pico de la pandemia de COVID-19.

INTRODUCTION: The COVID-19 pandemic has led to the suspension of programmed activity in most of the Endoscopy Units in our environment. The aim of this document is to facilitate the resumption of elective endoscopic activity in an efficient and safe manner. MATERIAL AND METHODS: A series of questions considered to be of clinical and logistical relevance were formulated. In order to elaborate the answers, a structured bibliographic search was carried out in the main databases and the recommendations of the main Public Health and Digestive Endoscopy institutions were reviewed. The final recommendations were agreed upon through telematic means. RESULTS: A total of 33 recommendations were made. The main aspects discussed are: 1) Reassessment and prioritization of the indication, 2) Restructuring of spaces, schedules and health personnel, 3) Screening for infection, 4) Hygiene measures and personal protective equipment. CONCLUSION: The AEG and SEED recommend restarting endoscopic activity in a phased, safe manner, adapted to local resources and the epidemiological situation of SARS-CoV-2 infection.

High-flow nasal cannulae for respiratory support in adult intensive care patients.

BACKGROUND: High-flow nasal cannulae (HFNC) deliver high flows of blended humidified air and oxygen via wide-bore nasal cannulae and may be useful in providing respiratory support for adults experiencing acute respiratory failure, or at risk of acute respiratory failure, in the intensive care unit (ICU). This is an update of an earlier version of the review. OBJECTIVES: To assess the effectiveness of HFNC compared to standard oxygen therapy, or non-invasive ventilation (NIV) or non-invasive positive pressure ventilation (NIPPV), for respiratory support in adults in the ICU. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, CINAHL, Web of Science, and the Cochrane COVID-19 Register (17 April 2020), clinical trial registers (6 April 2020) and conducted forward and backward citation searches. SELECTION CRITERIA: We included randomized controlled studies (RCTs) with a parallel-group or cross-over design comparing HFNC use versus other types of non-invasive respiratory support (standard oxygen therapy via nasal cannulae or mask; or NIV or NIPPV which included continuous positive airway pressure and bilevel positive airway pressure) in adults admitted to the ICU. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures as expected by Cochrane. MAIN RESULTS: We included 31 studies (22 parallel-group and nine cross-over designs) with 5136 participants; this update included 20 new studies. Twenty-one studies compared HFNC with standard oxygen therapy, and 13 compared HFNC with NIV or NIPPV; three studies included both comparisons. We found 51 ongoing studies (estimated 12,807 participants), and 19 studies awaiting classification for which we could not ascertain study eligibility information. In 18 studies, treatment was initiated after extubation. In the remaining studies, participants were not previously mechanically ventilated. HFNC versus standard oxygen therapy HFNC may lead to less treatment failure as indicated by escalation to alternative types of oxygen therapy (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.45 to 0.86; 15 studies, 3044 participants; low-certainty evidence). HFNC probably makes little or no difference in mortality when compared with standard oxygen therapy (RR 0.96, 95% CI 0.82 to 1.11; 11 studies, 2673 participants; moderate-certainty evidence). HFNC probably results in little or no difference to cases of pneumonia (RR 0.72, 95% CI 0.48 to 1.09; 4 studies, 1057 participants; moderate-certainty evidence), and we were uncertain of its effect on nasal mucosa or skin trauma (RR 3.66, 95% CI 0.43 to 31.48; 2 studies, 617 participants; very low-certainty evidence). We found low-certainty evidence that HFNC may make little or no difference to the length of ICU stay according to the type of respiratory support used (MD 0.12 days, 95% CI -0.03 to 0.27; 7 studies, 1014 participants). We are uncertain whether HFNC made any difference to the ratio of partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2) within 24 hours of treatment (MD 10.34 mmHg, 95% CI -17.31 to 38; 5 studies, 600 participants; very low-certainty evidence). We are uncertain whether HFNC made any difference to short-term comfort (MD 0.31, 95% CI -0.60 to 1.22; 4 studies, 662 participants, very low-certainty evidence), or to long-term comfort (MD 0.59, 95% CI -2.29 to 3.47; 2 studies, 445 participants, very low-certainty evidence). HFNC versus NIV or NIPPV We found no evidence of a difference between groups in treatment failure when HFNC were used post-extubation or without prior use of mechanical ventilation (RR 0.98, 95% CI 0.78 to 1.22; 5 studies, 1758 participants; low-certainty evidence), or in-hospital mortality (RR 0.92, 95% CI 0.64 to 1.31; 5 studies, 1758 participants; low-certainty evidence). We are very uncertain about the effect of using HFNC on incidence of pneumonia (RR 0.51, 95% CI 0.17 to 1.52; 3 studies, 1750 participants; very low-certainty evidence), and HFNC may result in little or no difference to barotrauma (RR 1.15, 95% CI 0.42 to 3.14; 1 study, 830 participants; low-certainty evidence). HFNC may make little or no difference to the length of ICU stay (MD -0.72 days, 95% CI -2.85 to 1.42; 2 studies, 246 participants; low-certainty evidence). The ratio of PaO2/FiO2 may be lower up to 24 hours with HFNC use (MD -58.10 mmHg, 95% CI -71.68 to -44.51; 3 studies, 1086 participants; low-certainty evidence). We are uncertain whether HFNC improved short-term comfort when measured using comfort scores (MD 1.33, 95% CI 0.74 to 1.92; 2 studies, 258 participants) and responses to questionnaires (RR 1.30, 95% CI 1.10 to 1.53; 1 study, 168 participants); evidence for short-term comfort was very low certainty. No studies reported on nasal mucosa or skin trauma. AUTHORS' CONCLUSIONS: HFNC may lead to less treatment failure when compared to standard oxygen therapy, but probably makes little or no difference to treatment failure when compared to NIV or NIPPV. For most other review outcomes, we found no evidence of a difference in effect. However, the evidence was often of low or very low certainty. We found a large number of ongoing studies; including these in future updates could increase the certainty or may alter the direction of these effects.

ANTECEDENTES: Las cánulas nasales de alto flujo (HFNC) administran flujos elevados de una mezcla humedecida de aire y oxígeno a través de cánulas nasales de gran calibre y pueden ser útiles para proporcionar asistencia respiratoria a los adultos que presentan insuficiencia respiratoria aguda, o que tienen riesgo de presentarla, en la unidad de cuidados intensivos (UCI). Esta es una actualización de una versión anterior de la revisión. OBJETIVOS: Evaluar la eficacia de las HFNC en comparación con la oxigenoterapia estándar, o la ventilación no invasiva (VNI) o la ventilación con presión positiva no invasiva (VPPNI), para la asistencia respiratoria de adultos en la UCI. MÉTODOS DE BÚSQUEDA: Se realizaron búsquedas en CENTRAL, MEDLINE, Embase, CINAHL, Web of Science y en el Registro Cochrane de covid­19 (17 de abril de 2020), registros de ensayos clínicos (6 de abril de 2020) y se realizaron búsquedas de citas prospectivas y retrospectivas. CRITERIOS DE SELECCIÓN: Se incluyeron los estudios controlados aleatorizados (ECA) con un diseño de grupos paralelos o cruzados que compararon el uso de HFNC versus otro tipo de asistencia respiratoria no invasiva (oxigenoterapia estándar a través de cánulas nasales o mascarilla; o VNI o VPPNI que incluía la presión positiva continua en las vías respiratorias y la presión positiva de dos niveles en las vías respiratorias) en adultos ingresados en la UCI. OBTENCIÓN Y ANÁLISIS DE LOS DATOS: Se utilizaron los procedimientos metodológicos estándar previstos por la Colaboración Cochrane. RESULTADOS PRINCIPALES: Se incluyeron 31 estudios (22 de grupos paralelos y nueve de diseño cruzado) con 5136 participantes; esta actualización incluyó 20 estudios nuevos. Veintiún estudios compararon la HFNC con la oxigenoterapia estándar, y 13 compararon la HFNC con la VNI o la VPPNI; tres estudios incluyeron ambas comparaciones. Se encontraron 51 estudios en curso (con una estimación de 12 807 participantes) y 19 estudios en espera de clasificación en los que no fue posible determinar la información de elegibilidad del estudio. En 18 estudios el tratamiento se inició después de la extubación. En el resto de los estudios, los participantes no habían recibido de forma previa ventilación mecánica. HFNC versus oxigenoterapia estándar La HFNC podría conducir a un menor fracaso del tratamiento, según lo indicado por el escalamiento a tipos alternativos de oxigenoterapia (razón de riesgos [RR] 0,62; intervalo de confianza [IC] del 95%: 0,45 a 0,86; 15 estudios, 3044 participantes; evidencia de certeza baja). La HFNC probablemente da lugar a poca o ninguna diferencia en la mortalidad cuando se compara con la oxigenoterapia estándar (RR 0,96; IC del 95%: 0,82 a 1,11; 11 estudios, 2673 participantes; evidencia de certeza moderada). La HFNC probablemente da lugar a poca o ninguna diferencia con respecto a los casos de neumonía (RR 0,72; IC del 95%: 0,48 a 1,09; cuatro estudios, 1057 participantes; evidencia de certeza moderada), y no se sabe con certeza su efecto sobre la mucosa nasal ni el traumatismo cutáneo (RR 3,66; IC del 95%: 0,43 a 31,48; dos estudios, 617 participantes; evidencia de certeza muy baja). Se encontró evidencia de certeza baja de que la HFNC podría dar lugar a poca o ninguna diferencia en la duración de la estancia en la UCI según el tipo de asistencia respiratoria utilizada (DM 0,12 días; IC del 95%: ­0,03 a 0,27; siete estudios, 1014 participantes). No se sabe con certeza si la HFNC dio lugar a alguna diferencia en el cociente entre la presión parcial de oxígeno arterial y la fracción de oxígeno inspirado (PaO2/FiO2) en las primeras 24 horas del tratamiento (DM 10,34 mmHg; IC del 95%: ­17,31 a 38; cinco estudios, 600 participantes; evidencia de certeza muy baja). No se sabe con certeza si la HFNC dio lugar a alguna diferencia en la comodidad a corto plazo (DM 0,31; IC del 95%: ­0,60 a 1,22; cuatro estudios, 662 participantes, evidencia de certeza muy baja), o en la comodidad a largo plazo (DM 0,59; IC del 95%: ­2,29 a 3,47; dos estudios, 445 participantes, evidencia de certeza muy baja). HFNC versus VNI o VPPNI No se encontró evidencia de una diferencia entre los grupos en el fracaso del tratamiento cuando se utilizó la HFNC después de la extubación o sin el uso previo de ventilación mecánica (RR 0,98; IC del 95%: 0,78 a 1,22; cinco estudios, 1758 participantes; evidencia de certeza baja), ni en la mortalidad hospitalaria (RR 0,92; IC del 95%: 0,64 a 1,31; cinco estudios, 1758 participantes; evidencia de certeza baja). No hay certeza sobre el efecto del uso de la HFNC en la incidencia de la neumonía (RR 0,51; IC del 95%: 0,17 a 1,52; tres estudios, 1750 participantes; evidencia de certeza muy baja), y la HFNC podría dar lugar a poca o ninguna diferencia en el barotraumatismo (RR 1,15; IC del 95%: 0,42 a 3,14; un estudio, 830 participantes; evidencia de certeza baja). La HFNC podría suponer una diferencia escasa o nula en la duración de la estancia en la UCI (DM ­0,72 días; IC del 95%: ­2,85 a 1,42; dos estudios, 246 participantes; evidencia de certeza baja). El cociente PaO2/FiO2 podría ser menor hasta 24 horas con el uso de la HFNC (DM ­58,10 mmHg; IC del 95%: ­71,68 a ­44,51; tres estudios, 1086 participantes; evidencia de certeza baja). No se sabe si la HFNC mejoró la comodidad a corto plazo cuando se midió mediante puntuaciones de comodidad (DM 1,33; IC del 95%: 0,74 a 1,92; dos estudios, 258 participantes) y respuestas a cuestionarios (RR 1,30; IC del 95%: 1,10 a 1,53; un estudio, 168 participantes); la evidencia para la comodidad a corto plazo fue de certeza muy baja. Ningún estudio informó sobre la mucosa nasal ni el traumatismo cutáneo. CONCLUSIONES DE LOS AUTORES: La HFNC podría dar lugar a un menor fracaso del tratamiento en comparación con la oxigenoterapia estándar, pero probablemente suponga una escasa o nula diferencia en el fracaso del tratamiento en comparación con la VNI o la VPPNI. Para la mayoría de los demás desenlaces de la revisión, no se encontró evidencia de una diferencia en el efecto. Sin embargo, la certeza de la evidencia se consideró baja o muy baja. Se encontró un gran número de estudios en curso; incluirlos en futuras actualizaciones podría aumentar la certeza o podría alterar la dirección de estos efectos.

The use of oxygen hoods in patients failing on conventional high-flow oxygen delivery systems, the effects on oxygenation, mechanical ventilation and mortality rates in hypoxic patients with COVID-19. A Prospective Controlled Cohort Study.

INTRODUCTION: Efforts to meet increased oxygen demands in COVID-19 patients are a priority in averting mechanical ventilation (MV), associated with high mortality approaching 76.4-97.2%. Novel methods of oxygen delivery could mitigate that risk. Oxygen hoods/helmets may improve: O2-saturation (SaO2), reduce in-hospital mechanical ventilation and mortality rates, and reduce length of hospitalization in hypoxic Covid-19 patients failing on conventional high-flow oxygen delivery systems. METHODS: DesignProspective Controlled Cohort Study. SettingSingle Center. ParticipantsAll patients admitted with a diagnosis of COVID-19 were reviewed and 136/347 patients met inclusion criteria. Study period3/6/2020 to 5/1/2020. 136 participants completed the study with known status for all outcome measures. Intervention or exposureOxygen hoods/helmets as compared to conventional high-flow oxygen delivery systems. MAIN OUTCOME(S) AND MEASURE(S): 1) Pre and post change in oxygen saturation (SaO2). 2) In-hospital Mechanical Ventilation (MV). 3) In-hospital Mortality. 4) Length of hospitalization. RESULTS: 136 patients including 58-intervention and 78-control patients were studied. Age, gender, and other demographics/prognostic indicators were comparable between cohorts. Oxygen hoods averted imminent or immediate intubation/MV in all 58 COVID-19 patients failing on conventional high-flow oxygen delivery systems with a mean improvement in SaO2 of 8.8%, p < 0.001. MV rates were observed to be higher in the control 37/78 (47.4%) as compared to the intervention cohort 23/58 (39.7%), a difference of 7.7%, a 27% risk reduction, not statistically significant, OR 95%CI 0.73 (0.37-1.5). Mortality rates were observed higher in the control 54/78 (69.2%) as compared to the intervention cohort 36/58 (62.1%), a difference of 7.1%, a 27% risk reduction, not statistically significant OR 95%CI 0.73 (0.36-1.5). CONCLUSION: Oxygen hoods demonstrate improvement in SaO2 for patients failing on conventional high-flow oxygen-delivery systems and prevented imminent mechanical ventilation. In-hospital mechanical ventilation and mortality rates were reduced with the use of oxygen hoods but not found to be statistically significant. The oxygen hood is a safe, effective oxygen-delivery system which may reduce intubation/MV and mortality rates. Their use should be considered in treating hypoxic COVID-19 patients. Further research is warranted. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04407260.

Ventilators are not the answer in Africa.

The treatment of severely ill coronavirus disease 2019 (COVID-19) patients has brought the worldwide shortage of oxygen and ventilator-related resources to public attention. Ventilators are considered as the vital equipment needed to manage these patients, who account for 3% - 5% of patients with Covid-19. Most patients need oxygen and supportive therapy. In Africa, the shortage of oxygen is even more severe and needs equipment that is simpler to use than a ventilator. Different models of generating oxygen locally at hospitals, including at provincial and district levels, are required. In some countries, hospitals have established small oxygen production plants to supply themselves and neighbouring hospitals. Oxygen concentrators have also been explored but require dependable power supply and are influenced by local factors such as ambient temperature and humidity. By attaching a reservoir tank, the effect of short power outages or high demands can be smoothed over. The local and regional energy unleashed in the citizens to respond to the COVID-19 pandemic should now be directed towards developing appropriate infrastructure for oxygen and critical care. This infrastructure is education and technology intensive, requiring investment in these areas.

Use of Helmet CPAP in COVID-19 - A practical review.

Helmet CPAP (H-CPAP) has been recommended in many guidelines as a noninvasive respiratory support during COVID-19 pandemic in many countries around the world. It has the least amount of particle dispersion and air contamination among all noninvasive devices and may mitigate the ICU bed shortage during a COVID surge as well as a decreased need for intubation/mechanical ventilation. It can be attached to many oxygen delivery sources. The MaxVenturi setup is preferred as it allows for natural humidification, low noise burden, and easy transition to HFNC during breaks and it is the recommended transport set-up. The patients can safely be proned with the helmet. It can also be used to wean the patients from invasive mechanical ventilation. Our article reviews in depth the pathophysiology of COVID-19 ARDS, provides rationale of using H-CPAP, suggests a respiratory failure algorithm, guides through its setup and discusses the issues and concerns around using it.

Maintaining a high inspired oxygen fraction with the Elisée 350 turbine transport ventilator connected to two portable oxygen concentrators in an austere environment.

BACKGROUND: Management of critically ill patients requiring mechanical ventilation in austere environments or during disaster response is a logistic challenge. Availability of oxygen cylinders for mechanically ventilated patient may be difficult in such a context. A solution to ventilate patients requiring high fraction of inspired oxygen (FiO2) is to use a ventilator able to be supplied by a low-pressure oxygen source connected with two oxygen concentrators (OCs). We tested the Elisée 350 (ResMedBella Vista, Australia) ventilator paired with two Newlife Intensity 10 (Airsep, Ball Ground, Georgia) OCs and evaluated the delivered FiO2 across a range of minute volumes and combinations of ventilator settings. METHODS: The ventilators were attached to a test lung, OC flow was adjusted with a Certifier FA ventilator test systems from 2 to 10 L/min and injected into the oxygen inlet port of the Elisée 350. The FiO2 was measured by the analyzer integrated in the ventilator, controlled by the ventilator test system. Several combinations of ventilator settings were evaluated to determine the factors affecting the delivered FiO2. RESULTS: The Elisée 350 ventilator is a turbine ventilator able to deliver high FiO2 when functioning with two OCs. However, modifications of the ventilator settings such as an increase in minute ventilation affect delivered FiO2 even if oxygen flow is constant on the OC. CONCLUSION: The ability of two OCs to deliver high FiO2 when used with a turbine ventilator makes this method of oxygen delivery a viable alternative to cylinders to ventilate patients requiring an FiO2 of ≥80% in austere place or during disaster response. LEVEL OF EVIDENCE: Feasibility study on test bench, level V.

Oxygen therapy via high flow nasal cannula in severe respiratory failure caused by Sars-Cov-2 infection: a real-life observational study.

The worldwide spread of coronavirus disease 2019 (COVID-19), caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic by the World Health Organization (WHO) in March 2020. According to clinical studies carried out in China and Italy, most patients experience mild or moderate symptoms; about a fifth of subjects develop a severe and critical disease, and may suffer from interstitial pneumonia, possibly associated with acute respiratory distress syndrome (ARDS) and death.In patients who develop respiratory failure, timely conventional oxygen therapy through nasal catheter plays a crucial role, but it can be used only in mild forms. Continuous positive airway pressure (CPAP) support or non-invasive mechanical ventilation (NIV) are uncomfortable, and require significant man-machine cooperation. Herein we describe our experience of five patients with COVID-19, who were treated with high-flow nasal cannula (HFNC) after failure of CPAP or NIV, and discuss the role of HFNC in COVID-19 patients. Our findings suggest that HFNC can be used successfully in selected patients with COVID-19-related ARDS.The reviews of this paper are available via the supplemental material section.