COVID-19 pneumonia - increased incidence of pneumothorax/mediastinal emphysema after invasive mechanical and non-invasive ventilation.

Introduction: COVID pneumonia can lead to pneumomediastinum or pneumothorax during non-invasive or invasive mechanical ventilation. This affects the prognosis. Methodology: During the study period, 121 patients with SARS-CoV-2 infections and invasive or non-invasive ventilation therapy were recorded in our hospital. All patients with a pneumothorax or pneumomediastinum were analyzed in more detail. Result(s): Pneumothorax and pneumomediastinum occurred in 12 patients and resulted in 7 deaths. Discussion(s): The incidence of pneumothorax with COVID infection ranges from 0.56 to 1%, reaching 3.5% in our own studies and 4.2% under invasive mechanical ventilation. The incidence of pneumomediastinum was 10% and 9.2% in our own patients. Overall mortality was 58.3% and similar to that reported in the literature, up to 60%.Copyright © 2023 Dustri-Verlag Dr. K. Feistle.

Modified respiratory rate oxygenation index: an early warning index for the need of intubation in COVID-19 patients with high-flow nasal cannula therapy

Background High-flow nasal cannula oxygen therapy (HFNC) is recommended for COVID-19 patients. However, the increasing use of HFNC brings a risk of delayed intubation. The optimal timing of switching from HFNC to invasive mechanical ventilation (IMV) remains unclear. An effective predictor is needed to assist in deciding on the timing of intubation. Respiratory rate and oxygenation (ROX) index, defined as (SpO2/FiO2)/respiratory rate, already show good diagnostic accuracy. Modified ROX (mROX) index, defined as (PaO2/FiO2)/respiratory rate, might be better than the ROX index in predicting HFNC failure. Objective The aim was to evaluate the predictive value of mROX for HFNC failure in COVID-19 patients. Methods Severe or critical COVID-19 patients treated with HFNC were enrolled in two clinical centers. Laboratory indicators, respiratory parameters, and mROX index at 0 h and 2 h after initial HFNC were collected. Based on the need of IMV after HFNC initiation, the patients were divided into the HFNC failure group and the HFNC success group. The predictive value of mROX index for IMV was evaluated by the area under the receiver operating characteristic curve (AUROC) and logistic regression analysis. We performed Kaplan–Meier survival analysis using the log-rank test. Results Sixty COVID-19 patients (mean age, 62.8 ± 14.1 years;42 males) receiving HFNC were evaluated, including 18 critical and 42 severe cases. A total of 33 patients had hypertension;14 had diabetes;17 had chronic cardiac disease;11 had chronic lung disease;13 had chronic kidney disease;and 17 had a history of stroke. The AUROC of mROX index at 2 h was superior than that of other respiratory parameters to predict the need of IMV (0.959;P < 0.001). At the mROX index cutoff point of 4.45, predicting HFNC failure reached the optimal threshold, with specificity of 94% and sensitivity of 92%. Logistic regression analysis showed that 2-h mROX index below 4.45 was a protective factor for IMV (OR 0.18;95% CI, 0.05 to 0.64;P = 0.008). In the HFNC failure group, the median time from HFNC to IMV was 22.5 h. The 28-day mortality of the late intubation patients (≥22.5 h) was higher than that of the early intubation patients (<22.5 h) (53.8% vs 8.3%, P = 0.023). Conclusion mROX at 2 h is a good early warning index for the need of IMV in COVID-19 patients after HFNC initiation. Early intubation may lead to better survival in patients with 2-h mROX index below 4.45.

Indications for Intubation in COVID-19

Intubation and invasive mechanical ventilation are often unavoidable in most severe cases of COVID-19 pneumonia;however, deciding the optimum timing and best practices of intubation is challenging. The decision to proceed with intubation should be based on an integrated patient evaluation and not limited to the assessment of the severity of hypoxemia alone. Intubation is a maneuver exposing the operator to a high risk of contamination, therefore adequate personal protection equipment is mandatory. Benefits of intubation over noninvasive respiratory support include reduction or suppression of the respiratory drive, reduction of the basal metabolism and allowance of maintaining protective mechanical ventilation. On the other hand, risks are related to the need for sedation, the presence of an artificial airway and exposure to mechanical ventilation, which may result in overlapping ventilator-associated bacterial pneumonia and ventilator-induced lung injury. Balancing between risks and benefits of intubation in this context is challenging and the optimum timing of intubation remains largely an open question. This chapter discusses the clinical, technical, and safety aspects that deserve to be considered when considering intubation in patients with severe COVID-19-related acute respiratory failure. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.

Lung ultrasound scoring system vs ROX index as a predictor for progression to the invasive mechanical ventilation in COVID-19 patients

Background: During the outbreak of the highly contagious Coronavirus disease 19 (COVID19), rapid and simple prognostic tools were needed to support clinical decisions and predict the need of invasive mechanical ventilation. the ROX index, and the lung ultrasound score (LUSS) were proposed to objectively predict patient prognosis in addition to the subjective clinical assessment Aim: This study aimed to compare lung ultrasound score with ROX index in predicting the need of invasive ventilation in COVID-19 patients requiring advanced oxygen therapy. Patients and Methods: We studied 50 patients with severe COVID-19 pneumonia in the intensive care unit in the isolated area at Kasr Al-Ainy hospital. Complete Medical history, physical examination and laboratory investigations were obtained on admission. All patients underwent bedside lung ultrasonography scan and LUSS was calculated at the 2nd and the 12th hours, also ROX index was calculated at the 2nd, 6th and 12th hours from initiating the advanced oxygen therapy. Result(s): From a total of fifty patients with COVID-19, 56.0% were males, with mean age of 65.98 + 11.68 years, and mortality rate was 68%. The optimal cut off value of the ROX index at (2, 6, 12 hour) is (2.495, 2.675, 3.06) respectively, (p <0.001) with sensitivity 90.9% and specificity 76.5% at the 12 hour. Also the optimal cut off point of LUSS is 25.50 (p <0.001) with sensitivity 93.9% and specificity 88.2% for prediction of the invasive mechanical ventilation. Conclusion and recommendations: The study concluded that LUSS is more sensitive in predicting the need of invasive mechanical ventilation than ROX index.Copyright © 2023, Codon Publications. All rights reserved.

Risk of air and surface contamination during application of different noninvasive respiratory support for patients with COVID-19.

OBJECTIVES: We compared the risk of environmental contamination among patients with COVID-19 who received high-flow nasal cannula (HFNC), noninvasive ventilation (NIV), and conventional oxygen therapy (COT) via nasal cannula for respiratory failure. METHODS: Air was sampled from the hospital isolation rooms with 12 air changes/hr where 26 patients with COVID-19 received HFNC (up to 60 l/min, n = 6), NIV (n = 6), or COT (up to 5 l/min of oxygen, n = 14). Surface samples were collected from 16 patients during air sampling. RESULTS: Viral RNA was detected at comparable frequency in air samples collected from patients receiving HFNC (3/54, 5.6%), NIV (1/54, 1.9%), and COT (4/117, 3.4%) (P = 0.579). Similarly, the risk of surface contamination was comparable among patients receiving HFNC (3/46, 6.5%), NIV (14/72, 19.4%), and COT (8/59, 13.6%) (P = 0.143). An increment in the cyclic thresholds of the upper respiratory specimen prior to air sampling was associated with a reduced SARS-CoV-2 detection risk in air (odds ratio 0.83 [95% confidence interval 0.69-0.96], P = 0.027) by univariate logistic regression. CONCLUSION: No increased risk of environmental contamination in the isolation rooms was observed in the use of HFNC and NIV vs COT among patients with COVID-19 with respiratory failure. Higher viral load in the respiratory samples was associated with positive air samples.

High Flow Nasal Cannula Versus Noninvasive Positive Pressure Ventilation as Initial Respiratory Support in Patients with Chronic Obstructive Pulmonary Disease and Covid-19: Exploratory Analysis in Two Intensive Care Units.

OBJECTIVE: To identify the type of the non-invasive ventilatory treatment for patients diagnosed with chronic obstructive pulmonary disease (COPD), with respiratory status deteriorated by COVID-19 pneumonia, and in need of treatment in the Intensive Care Unit (ICU). MATERIALS AND METHODS: This cross-sectional study was conducted over a one-year period in the medical intensive care units of two hospitals. As the patients' clinical condition deteriorated and the parameters of the arterial blood gas (ABG) analysis worsened, oxygen support was applied via a high flow nasal cannula (HFNC) or by non-invasive positive pressure ventilation (NPPV). According to the control values of the arterial oxygen saturation (SaO2) and the parameters of ABG, the patients were enabled to be transferred between the two types of non-invasive ventilatory support. The primary outcome was the length of hospital stay, while secondary outcomes were the rate of intubation, the mortality rate, and respiratory supportfree days. RESULTS: Out of 21 critical patients with COPD and COVID-19, 11 (52.4%) were initially treated with NPPV and 10 (47.6%) with HFNC. The ages (67±9.79 in NPPV group vs. 70.10±10.25 in HFNC group) and severity of illness (SOFA score 5 (3.5) in NPPV group vs. 5 (2.8) in HFNC group) were similar between the two groups. Switching the mode of respiratory support was more common in NPPV (58.3% in survivor group vs. 41.7% in non-survivor group). Patients treated with NPPV compared to HFNC had a nominally longer length of stay (15 (11) vs. 11.5 (4.25)), and higher risk of intubation (66.7% vs. 33.3%) and mortality (66.7% vs. 33.3%), but the comparisons did not reach statistical significance. Survivors had significantly longer Medical Intensive Care Unit and hospital stays, but significantly lower FiO2 (0.60 vs.1) and higher values of PaO2/FiO2 (78(32.4) vs. 56.3(17.8)) than non-survivors. All patients were treated with corticosteroids, and the duration of treatment was similar between groups. CONCLUSION: In critically ill patients with COPD and COVID-19, both HFNC and NPPV were commonly used as the initial mode of ventilation. Switching to a different mode and adverse patient outcomes were more frequent in patients initially treated with NPPV. Survivors had higher values of PaO2/FiO2 than non-survivors.

Aerosol delivery through high-flow nasal therapy: Technical issues and clinical benefits.

High-flow nasal cannula (HFNC) therapy is an oxygen delivery method particularly used in patients affected by hypoxemic respiratory failure. In comparison with the conventional "low flow" oxygen delivery systems, it showed several important clinical benefits. The possibility to nebulize drugs via HFNC represents a desirable medical practice because it allows the administration of inhaled drugs, mostly bronchodilators, without the interruption or modification of the concomitant oxygen therapy. HFNC, by itself has shown to exert a small but significant bronchodilator effect and improves muco-ciliary clearance; thus, the nebulization of bronchodilators through the HFNC circuit may potentially increase their pharmacological activity. Several technical issues have been observed which include the type of the nebulizer that should be used, its position within the HFNC circuit, and the optimal gas flow rates to ensure an efficient drug delivery to the lungs both in "quiet" and "distressed" breathing patterns. The aim of this review has been to summarize the scientific evidence coming from "in vitro" studies and to discuss the results of "in vivo" studies performed in adult subjects, mainly affected by obstructive lung diseases. Most studies seem to indicate the vibrating mesh nebulizer as the most efficient type of nebulizer and suggest to place it preferentially upstream from the humidifier chamber. In a quite breathing patterns, the inhaled dose seems to increase with lower flow rates while in a "distressed" breathing pattern, the aerosol delivery is higher when gas flow was set below the patient's inspiratory flow, with a plateau effect seen when the gas flow reaches approximately 50% of the inspiratory flow. Although several studies have demonstrated that the percentage of the loaded dose nebulized via HFNC reaching the lungs is small, the bronchodilator effect of albuterol seems not to be impaired when compared to the conventional inhaled delivery methods. This is probably attributed to its pharmacological activity. Prospective and well-designed studies in different cohort of patients are needed to standardize and demonstrate the efficacy of the procedure.

Effect of the Early Combination of Continuous Positive Airway Pressure and High-Flow Nasal Cannula on Mortality and Intubation Rates in Patients With COVID-19 and Acute Respiratory Distress Syndrome. The DUOCOVID Study.

INTRODUCTION: Non invasive respiratory support (NIRS) is useful for treating acute respiratory distress syndrome (ARDS) secondary to COVID-19, mainly in mild-moderate stages. Although continuous positive airway pressure (CPAP) seems superior to other NIRS, prolonged periods of use and poor adaptation may contribute to its failure. The combination of CPAP sessions and high-flow nasal cannula (HFNC) breaks could improve comfort and keep respiratory mechanics stable without reducing the benefits of positive airway pressure (PAP). Our study aimed to determine if HFNC+CPAP initiates early lower mortality and endotracheal intubation (ETI) rates. METHODS: Subjects were admitted to the intermediate respiratory care unit (IRCU) of a COVID-19 monographic hospital between January and September 2021. They were divided according to Early HFNC+CPAP (first 24h, EHC group) and Delayed HFNC+CPAP (after 24h, DHC group). Laboratory data, NIRS parameters, and the ETI and 30-day mortality rates were collected. A multivariate analysis was performed to identify the risk factors associated with these variables. RESULTS: The median age of the 760 included patients was 57 (IQR 47-66), who were mostly male (66.1%). The median Charlson Comorbidity Index was 2 (IQR 1-3) and 46.8% were obese. The median PaO2/FiO2 upon IRCU admission was 95 (IQR 76-126). The ETI rate in the EHC group was 34.5%, with 41.8% for the DHC group (p=0.045), while 30-day mortality was 8.2% and 15.5%, respectively (p=0.002). CONCLUSIONS: Particularly in the first 24h after IRCU admission, the HFNC+CPAP combination was associated with a reduction in the 30-day mortality and ETI rates in patients with ARDS secondary to COVID-19.

High flow nasal cannula for acute respiratory failure due to COVID-19 in patients with a 'do-not-intubate' order: A survival analysis.

INTRODUCTION: High flow nasal cannula (HFNC) reduces the need for intubation in patients with hypoxaemic acute respiratory failure (ARF), but its added value in patients with severe coronavirus disease 2019 (COVID-19) and a do-not-intubate (DNI) order is unknown. We aimed to assess (variables associated with) survival in these patients. MATERIALS AND METHODS: We described a multicentre retrospective observational cohort study in five hospitals in the Netherlands and assessed the survival in COVID-19 patients with severe acute respiratory failure and a DNI order who were treated with high flow nasal cannula. We also studied variables associated with survival. RESULTS AND DISCUSSION: One-third of patients survived after 30 days. Survival was 43.9% in the subgroup of patients with a good WHO performance status and only 16.1% in patients with a poor WHO performance status. Patients who were admitted to the hospital for a longer period prior to HFNC initiation were less likely to survive. HFNC resulted in an increase in ROX values, reflective of improved oxygenation and/or decreased respiratory rate. CONCLUSION: Our data suggest that a trial of HFNC could be considered to increase chances of survival in patients with ARF due to COVID-19 pneumonitis and a DNI order, especially in those with a good WHO performance status.

Enterovirus-Human-Rhinovirus Infection Leading to Acute Respiratory Distress Syndrome: A Case Report.

Enterovirus-human-rhinovirus (EV-HRV) is best known to cause the "common cold" and asthma exacerbations. Simple bronchitis and community-acquired pneumonia related to EV-HRV are also well documented. Scattered reports of rhinovirus causing acute respiratory distress syndrome (ARDS) have been published, yet the causality between recent SARS-CoV-2 pneumonia and severe ARDS secondary to EV-HRV has not been well defined. This case presents a 67-year-old male who was unvaccinated against SARS-CoV-2 with a past medical history of chronic obstructive pulmonary disease, who recently experienced a mild-to-moderate case of SARS-CoV-2 pneumonia, which was treated with dexamethasone and remdesivir. He was discharged to an inpatient psychiatric facility on as-needed oxygen via nasal cannula. Three weeks later, he experienced an episode of presyncope and was readmitted to the hospital. He then began to require increasing levels of supplemental oxygen via a high-flow nasal cannula. A real-time polymerase chain reaction respiratory pathogen panel was positive for EV-HRV. Computed tomography of the chest revealed extensive ground-glass opacities. Further workup for bacterial and fungal pneumonia was negative. Repeat SARS-CoV-2 testing was also negative. He required several days of supplemental oxygen via a high-flow nasal cannula. He received a short course of broad-spectrum antibiotics and a 10-day course of high-dose dexamethasone. Ultimately, he fully recovered, did not require further supplemental oxygen, and was discharged on room air.

The role of clinical engineers in the coronavirus disease 2019 pandemic.

The duties of a clinical engineer (CE) during the coronavirus infection 2019 (COVID-19) pandemic were diverse. The original duties of a CE included operation and maintenance of life support equipment used for respiratory therapy, hemodialysis, and extracorporeal membrane oxygenation. The management of life support equipment is critical. The PB-840 ventilator is equipped with a heat sink system that dissipates internal heat through thermal conduction. Therefore, internal contamination is less likely to occur. The exhalation filter used in the PB- 840 can be used for up to 15 days. It can be used for long periods of time without maintenance, reducing the risk of infection. The PB-840 is a suitable device for patients with COVID-19. Its use in critically ill patients was determined to be a priority. Thus, use of an appropriate device for infection control requires a proper understanding of and familiarity with the device in question.

Factors Associated With Non-invasive Oxygen Therapy Failure in COVID-19 Pneumonia: A Single Center, Retrospective Study in a Tertiary Hospital in North India.

BACKGROUND: Non-invasive oxygen therapy (NIT) consists of high-flow nasal oxygen (HFNO) and continuous positive airway pressure (CPAP). NIT is routinely being used for the management of acute respiratory failure secondary to coronavirus disease-2019 (COVID-19) with variable outcomes. However, previously published studies show that NIT failure might delay endotracheal intubation and invasive mechanical ventilation and results in worse outcomes in patients with hypoxemic respiratory failure. Early prediction of failure of NIT, will help in early decision-making in initiating invasive mechanical ventilation. We retrospectively studied the predictors for NIT failure in patients with moderate to severe COVID-19. METHODS: Adult patients (>18 years) admitted to the intensive care unit (ICU) with moderate to severe COVID-19 ARDS and received NIT [HFNO and CPAP non-invasive ventilation (NIV)] were included in this study. Baseline clinical and laboratory data were collected retrospectively from the electronic hospital information system. NIT failure was defined as the need for invasive mechanical ventilation after the initiation of NIT in the ICU. Univariate and multivariate logistic regression analyses were used to find out the possible predictors of NIT failure. RESULTS: Out of 254 patients admitted to ICU, 127 patients were initiated NIT at admission to ICU. During the course of the ICU stay, 33 (26%) patients subsequently required invasive mechanical ventilation (NIT failure). Respiratory rate-oxygenation index (ROX index) of <2.97 at two hours and <3.63 at six hours of ICU admission predicted NIT failure in our cohort of patients with a high positive predictive value. CONCLUSION: Patient selection is crucial for successful NIT in COVID-19. Application of ROX index measured in the first six hours of ICU admission helps in the identification of patients at risk of NIT failure with moderate to severe COVID-19 ARDS.

High-flow nasal cannula therapy, factors affecting effective inspired oxygen fraction: an experimental adult bench model.

Oxygenation through High Flow Delivery Systems (HFO) is described as capable of delivering accurate FiO2. Meanwhile, peak inspiratory flow [Formula: see text] ) of patients with acute hypoxemic respiratory failure can reach up to 120 L/min, largely exceeding HFO flow. Currently, very few data on the reliability of HFO devices at these high [Formula: see text] are available. We sought to evaluate factors affecting oxygenation while using HFO systems at high [Formula: see text] in a bench study. Spontaneous breathing was generated with a mechanical test lung connected to a mechanical ventilator Servo-i®, set to volume control mode. Gas flow from a HFO device was delivered to the test lung. The influence on effective inspired oxygen fraction of three parameters (FiO2 0.6, 0.8, and 1, [Formula: see text] from 28 to 98.1 L/min, and HFO Gas Flows from 40 to 60 L/min) were analyzed and are reported. The present bench study demonstrates that during HFO treatment, measured FiO2 in the lung does not equal set FiO2 on the device. The substance of this variation (ΔFiO2) is tightly correlated to [Formula: see text] (Pearson's coefficient of 0.94, p-value < 0.001). Additionally, set FiO2 and Flow at HFO device appear to significatively affect ΔFiO2 as well (p-values < 0.001, adjusted to [Formula: see text] ). The result of multivariate linear regression indicates predictors ([Formula: see text] , Flow and set FiO2) to explain 92% of the variance of delta FiO2 through K-Fold Cross Validation. Moreover, adjunction of a dead space in the breathing circuit significantly decreased ΔFiO2 (p < 0.01). The present bench study did expose a weakness of HFO devices in reliability of delivering accurate FIO2 at high [Formula: see text] as well as, to a lesser extent, at [Formula: see text] below equivalent set HFO Flows. Moreover, set HFO flow and set FIO2 did influence the variability of effective inspired oxygen fraction. The adjunction of a dead space in the experimental set-up significantly amended this variability and should thus be further studied in order to improve success rate of HFO therapy.

Characteristics and Results of Hospital Admission Caused by Influenza Virus Infections in Children under 5 Years Old.

AIMS: The influenza virus is an infectious disease with acute respiratory tract infections, caused secondary bacterial infections and death. In this study, we aimed to determine which predictors were associated with the need for high-flow nasal cannula oxygen therapy (HFNC) and transition to intensive care for influenza virus and also to compare single viral pathogens with multiple ones. METHODS: Inpatients under the age of 5 with influenza virus-related respiratory tract infections between November 2015 and March 2019 were included in the study. Demographic features, comorbidities, symptoms, secondary bacterial infection, need for HFNC and pediatric intensive care unit and respiratory support system, length of hospital stay, polymerase chain reaction tests were recorded. RESULTS: A total of 93 patients were included in the study. It was determined that 53.8% of the cases were male and 84.9% were under the age of 2. Comorbidities were present in 50.5% of the cases. Secondary bacterial pneumonia developed in 56.9% of the cases. Patients with secondary bacterial pneumonia had higher PICU need, HFNC need and hospital stay (p = 0.014, p ≤ 0.001 and p ≤ 0.001, respectively). Patients with comorbidity had longer hospital stays and a higher need for HFNC (p ≤ 0.001 and p = 0.001, respectively). CONCLUSIONS: In this study, it was determined that especially comorbidity and secondary bacterial infection aggravated the clinical treatment of hospitalized patients. Therefore, it was concluded that patients with comorbidity should be followed closely and secondary bacterial pneumonia should be recognized and treated early.

Increased use of high-flow nasal cannulas after the pandemic in bronchiolitis: a more severe disease or a changed physician's attitude?

After the SARS-CoV-2 pandemic, we noticed a marked increase in high-flow nasal cannula use for bronchiolitis. This study aims to report the percentage of children treated with high-flow nasal cannula (HFNC) in various seasons. The secondary outcomes were admissions for bronchiolitis, virological results, hospital burden, and NICU/PICU need. We conducted a retrospective study in four Italian hospitals, examining the medical records of all infants (< 12 months) hospitalized for bronchiolitis in the last four winter seasons (1 September-31 March 2018-2022). In the 2021-2022 winter season, 66% of admitted children received HFNC versus 23%, 38%, and 35% in the previous 3 years. A total of 876 patients were hospitalized in the study periods. In 2021-2022, 300 infants were hospitalized for bronchiolitis, 22 in 2020-2021, 259 in 2019-2020, and 295 in 2018-2019. The percentage of patients needing intensive care varied from 28.7% to 18%, 22%, and 15% in each of the four considered periods (p < 0.05). Seventy-seven percent of children received oxygen in the 2021-2022 winter; vs 50%, 63%, and 55% (p < 0.01) in the previous 3 years. NIV/CPAP was used in 23%, 9%, 16%, and 12%, respectively. In 2021-2020, 2% of patients were intubated; 0 in 2020-2021, 3% in 2019-2020, and 1% in 2018-2019. CONCLUSION: This study shows a marked increase in respiratory support and intensive care admissions this last winter. While these severity indexes were all driven by medical choices, more reliable indexes such as intubation rate and length of stay did not change. Therefore, we suggest that there is a more aggressive treatment attitude rather than a more severe disease. WHAT IS KNOWN: • COVID-19 pandemic deeply impacted bronchiolitis epidemiology, reducing hospitalizations to onetenth. In the 2021-2022 winter, bronchiolitis resurged to pre-pandemic numbers in Europe. WHAT IS NEW: • Bronchiolitis hospitalization rose much faster in the 2021-2022 winter period, peaking at a higher level. Respiratory supports and high-flow nasal cannula increased significantly compared to the pre-pandemic era.

High-Flow Nasal Cannula and Standard Oxygen in Acute Hypoxemic Respiratory Failure Due to COVID-19.

BACKGROUND: The evidence regarding benefits of high-flow nasal cannula (HFNC) in patients with COVID-19 is controversial. The aim of this study was to evaluate the impact of HFNC in comparison with standard oxygen therapy on the frequency of endotracheal intubation at 28 d in subjects with acute hypoxemic respiratory failure (AHRF) secondary to SARS-CoV-2 infection. METHODS: A retrospective, age- and sex-matched-paired, cohort study was conducted in subjects with moderate-to-severe AHRF. Intervention group was treated with HFNC, and control group was treated with standard oxygen therapy. Baseline characteristics and clinical evolution were analyzed. Mantel-Haenszel test was used for categorical variables. Paired samples Wilcoxon test was used for quantitative variables. Multivariate analysis was performed using conditional multiple logistic regression. RESULTS: Eighty-four subjects were included. The median time from admission to progression of oxygen therapy to FIO2 ≥ 0.5 or HFNC was 1 (interquartile range [IQR] 0-3) d. PaO2 /FIO2 at the time of oxygen therapy progression showed a median of 150.5 (IQR 100.0-170.0) for the entire sample and was lower in HFNC group compared with control group (median 135 [IQR 96-162] vs median 158 [IQR 132-174], respectively, P = .02). Endotracheal intubation at 28 d was observed in 54.8% HFNC and 73.8% standard oxygen (unadjusted odds ratio 0.38 [95% CI 0.13-1.07], P = .069). In the multivariate analysis, presence of dyspnea at hospital admission, Sequential Organ Failure Assessment score, and PaO2 /FIO2 at time of progression of oxygen therapy to FIO2 ≥ 0.5 was identified as confounding factors for the association between the intervention group and the outcome. Use of HFNC was not an independent predictor of endotracheal intubation frequency after adjusting confounders (odds ratio 0.26 [95% CI 0.04-1.51], P = .13). CONCLUSIONS: In this study, HFNC therapy in subjects with AHRF secondary to COVID-19 was not an independent predictor of endotracheal intubation, compared with standard oxygen therapy, after adjusting for confounders.

A Puzzling Diagnosis of Cerebral Vein Thrombosis in a COVID-19-Vaccinated Patient.

Cerebral vein thrombosis (CVT) is a rare condition equivalent to deep vein thrombosis of the intracranial veins. Delayed diagnosis will result in severe and disabling complications. We report a case of a 59-year-old man with CVT with no significant past medical or surgical history. On admission, he reported right-sided numbness and weakness concerns, preceded by the sudden onset of bilateral vision loss and dysarthria. Magnetic resonance imaging and computed tomography scans confirmed the diagnosis of CVT. The most interesting relative risk factor was flying overseas twice a month for the last 10 years; each flight was longer than eight hours. Another possible contributing factor to our patient's condition was polycythemia, with a hemoglobin level of 19, but the most questionable and puzzling is the recent coronavirus disease 2019 (COVID-19) vaccination two months, eight months, and one year prior to admission. Our case highlights a rare COVID-19 vaccine-related CVT diagnosis and that close monitoring for new symptoms and signs is vital to prevent life-threatening complications, herniation, and hemorrhagic transformation.

A Bench Comparison of the Effect of High-Flow Oxygen Devices on Work of Breathing.

BACKGROUND: Oxygen therapy via high-flow nasal cannula (HFNC) has been extensively used during the COVID-19 pandemic. The number of devices has also increased. We conducted this study to answer the following questions: Do HFNC devices differ from the original device for work of breathing (WOB) and generated PEEP? METHODS: Seven devices were tested on ASL 5000 lung model. Compliance was set to 40 mL/cm H2O and resistance to 10 cm H2O/L/s. The devices were connected to a manikin head via a nasal cannula with FIO2 set at 0.21. The measurements were performed at baseline (manikin head free of nasal cannula) and then with the cannula and the device attached with oxygen flow set at 20, 40, and 60 L/min. WOB and PEEP were assessed at 3 simulated inspiratory efforts (-5, -10, -15 cm H2O muscular pressure) and at 2 breathing frequencies (20 and 30 breaths/min). Data were expressed as median (first-third quartiles) and compared with nonparametric tests to the Optiflow device taken as reference. RESULTS: Baseline WOB and PEEP were comparable between devices. Over all the conditions tested, WOB was 4.2 (1.0-9.4) J/min with the reference device, and the relative variations from it were 0, -3 (2-4), 1 (0-1), -2 (1-2), -1 (1-2), and -1 (1-2)% with Airvo 2, G5, HM80, T60, V500, and V60 Plus devices, respectively, (P < .05 Kruskal-Wallis test). PEEP was 0.9 (0.3-1.5) cm H2O with Optiflow, and the relative differences were -28 (22-33), -41 (38-46), -30 (26-36), -31 (28-34), -37 (32-42), and -24 (21-34)% with Airvo 2, G5, HM80, T60, V500, and V60 Plus devices, respectively, (P < .05 Kruskal-Wallis test). CONCLUSIONS: WOB was marginally higher and PEEP marginally lower with devices as compared to the reference device.

Use of high flow nasal cannula as a modality of acute respiratory failure due to COVID-19

Oxygen (O2 ) therapy is the first-line therapy for acute respiratory distress with hypoxemia due to Coronavirus disease-2019 (COVID-19). High-flow nasal cannula (HFNC) therapy represents one of the O2 therapy alternative modalities. HFNC is a supportive O2 therapy device using a specially designed HFNC warmed and moisturizer, resulting in a stable flow rate. The physiological mechanisms of HFNC make its efficacy better than other O2 therapy applications. Management of COVID-19 focuses on preventing disease worsening, and HFNC can optimize the outcome of therapy. Further studies are necessary to evaluate the benefits of HFNC in hypoxemia management. It is also important to clarify its contraindications and factors associated with HFNC failure. [ FROM AUTHOR] Copyright of Gulhane Medical Journal is the property of Gulhane Military Medical Academy and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)