The utility of the respiratory rate-oxygenation index as a predictor of treatment response in dogs receiving high-flow nasal cannula oxygen therapy.

Objective: This study aims to evaluate the respiratory rate-oxygenation index (ROX) and the ratio of pulse oximetry saturation (SpO2) to the fraction of inspired oxygen (FiO2) (SpO2/FiO2, [SF]) to determine whether these indices are predictive of outcome in dogs receiving high-flow nasal cannula oxygen therapy (HFNOT). Design: This is a prospective observational study. Setting: This study was carried out at two university teaching hospitals. Animals: In total, 88 dogs treated with HFNOT for hypoxemic respiratory failure due to various pulmonary diseases were selected. Measurements and main results: The ROX index was defined as the SF divided by the respiratory rate (RR). ROX and SF were calculated at baseline and for each hour of HFNOT. The overall success rate of HFNOT was 38% (N = 33/88). Variables predicting HFNOT success were determined using logistic regression, and the predictive power of each variable was assessed using the area under the receiver operating curve (AUC). ROX and SF were adequately predictive of HFNOT success when averaged over 0-16 h of treatment, with similar AUCs of 0.72 (95% confidence interval [CI] 0.60-0.83) and 0.77 (95% CI 0.66-0.87), respectively (p < 0.05). SF showed acceptable discriminatory power in predicting HFNOT outcome at 7 h, with an AUC of 0.77 (95% CI 0.61-0.93, p = 0.013), and the optimal cutoff for predicting HFNC failure at 7 h was SF ≤ 191 (sensitivity 83% and specificity 76%). Conclusion: These indices were easily obtained in dogs undergoing HFNOT. The results suggest that ROX and SF may have clinical utility in predicting the outcomes of dogs on HFNOT. Future studies are warranted to confirm these findings in a larger number of dogs in specific disease populations.

Effectiveness, Adherence and Safety of Home High Flow Nasal Cannula in Chronic Respiratory Disease and Respiratory Insufficiency: A Systematic Review.

INTRODUCTION: The effectiveness of home high flow nasal cannula (HFNC) for the treatment of chronic respiratory failure in patients with chronic respiratory diseases (CRDs) has not been summarized. We aimed to conduct a systematic review of the effectiveness, adherence, and safety of HFNC in the long-term treatment of patients with chronic respiratory diseases and respiratory failure. METHODS: A systematic review was conducted. PubMed, Web of science, and SCOPUS were search up to August 2023. Long-term HFNC studies (≥4 weeks) reporting dyspnea; exacerbations, hospitalizations; peripheral oxygen saturation (SpO2), comfort; patient experience, health-related quality of life or partial pressure of carbon dioxide (paCO2) were included. RESULTS: Thirteen articles (701 patients) based on 10 studies were selected: randomized control trials (n=3), randomized crossover trials (n=2), crossover (n=3) and retrospective (n=2) studies. COPD (n=6), bronchiectasis (n=2), COPD/bronchiectasis (n=1) and ILD (n=1) were the underlined CRDs. HFNC reduced exacerbations when compared to usual care/home respiratory therapies (n=6). Quality of life outcomes were also in favor of HFNC in patients with COPD and bronchiectasis (n=6). HFNC had significant effects on hospitalizations, paCO2, and lung function. Adherence ranged from 5.2 to 8.6h/day (n=5). Three studies reported no events, 3 non-serious events and 2 no differences compared with other home respiratory therapies. CONCLUSIONS: HFNC seems more effective than usual care or other home respiratory therapies in reducing exacerbations and improving quality of life in patients with COPD and bronchiectasis, while presenting good adherence and being safe. Its apparently superior effectiveness needs to be better studied in future real-world pragmatic trials.

Randomized Controlled Trial Investigating the Impact of High-Flow Nasal Cannula Oxygen Therapy on Patients Undergoing Robotic-Assisted Laparoscopic Rectal Cancer Surgery, with a Post-Extubation Atelectasis as a Complication.

Background: Utilizing high-flow nasal cannula (HFNC) oxygen therapy may prevent the collapse of alveoli and improve overall alveolar ventilation. In this study, we aimed to investigate the impact of HFNC on postoperative atelectasis in individuals undergoing robotic-assisted laparoscopic surgery. Methods: Patients undergoing robotic-assisted laparoscopic surgery for rectal cancer were randomly assigned to the control or HFNC groups. After the surgical procedure was complete and the trachea was extubated, both groups underwent an initial lung ultrasound (LUS) scan. In the post-anesthesia care unit (PACU), the control group received conventional nasal cannula oxygen therapy, while the HFNC group received high-flow nasal cannula oxygen therapy. A second LUS scan was conducted before the patient was transferred to the ward. The primary outcome measured was the total LUS score at the time of PACU discharge. Results: In the HFNC group (n = 39), the LUS score and the incidence of atelectasis at PACU discharge were significantly lower compared to the control group (n = 39) [(5 vs 10, P < 0.001), (48.72% vs 82.05%, P = 0.002)]. None of the patients in the HFNC group experienced hypoxemia in the PACU, whereas six patients in the control group did (P = 0.03). Additionally, the minimum SpO2 value in the PACU was notably higher in the HFNC group compared to the control group [99 vs 97, P < 0.001]. Conclusion: Based on the results, HFNC improves the extent of postoperative atelectasis and decreases the occurrence of atelectasis in individuals undergoing robotic-assisted laparoscopic surgery for rectal cancer.

Continuous positive airway pressure versus high-flow nasal cannula oxygen therapy for acute hypoxemic respiratory failure: A randomized controlled trial.

BACKGROUND AND OBJECTIVE: The relative effectiveness of initial non-invasive respiratory strategies for acute respiratory failure using continuous positive airway pressure (CPAP) or high-flow nasal cannula (HFNC) is unclear. METHODS: We conducted a multicenter, open-label, parallel-group randomized controlled trial to compare the efficacy of CPAP and HFNC on reducing the risk of meeting the prespecified criteria for intubation and improving clinical outcomes of acute hypoxemic respiratory failure. The primary endpoint was the time taken to meet the prespecified criteria for intubation within 28 days. RESULTS: Eighty-five patients were randomly assigned to the CPAP or HFNC group. Eleven (28.9%) in the CPAP group and twenty (42.6%) in the HFNC group met the criteria for intubation within 28 days. Compared with HFNC, CPAP reduced the risk of meeting the intubation criteria (hazard ratio [HR], 0.327; 95% CI, 0.148-0.724; p = 0.006). There were no significant between-group differences in the intubation rates, in-hospital and 28-day mortality rates, ventilator-free days, duration of the need for respiratory support, or duration of hospitalization for respiratory illness. Pulmonary oxygenation was significantly better in the CPAP group, with significantly lower pH and higher partial pressure of carbon dioxide, but there were no differences in the respiratory rate between groups. CPAP and HFNC were associated with few possibly causal adverse events. CONCLUSION: CPAP is more effective than HFNC at reducing the risk of meeting the intubation criteria in patients with acute hypoxemic respiratory failure.

High-Flow Nasal Cannula oxygen therapy in COVID-19: retrospective analysis of clinical outcomes - single center experience.

Background: High-Flow Nasal Cannula (HFNC) oxygen therapy emerged as the therapy of choice in COVID-19-related pneumonia and moderate to severe acute hypoxemic respiratory failure (AHRF). HFNC oxygen therapy in COVID-19 has been recommended based its use to treat AHRF of other etiologies, and studies on assessing outcomes in COVID-19 patients are highly needed. This study aimed to examine outcomes in COVID-19 patients with pneumonia and severe AHRF treated with HFNC. Materials and methods: The study included 235 COVID-19 patients with pneumonia treated with HFNC. Data extracted from medical records included demographic characteristics, comorbidities, laboratory parameters, clinical and oxygenation status, clinical complications, as well as the length of hospital stay. Patients were segregated into two groups based on their oxygen therapy needs: HDU group, those who exclusively required HFNC and ICU group, those whose oxygen therapy needed to be escalated at some point of hospital stay. The primary outcome was the need for respiratory support escalation (noninvasive or invasive mechanical ventilation) and the secondary outcome was the in-hospital all-cause mortality. Results: The primary outcome was met in 113 (48%) of patients. The overall mortality was 70%, significantly higher in the ICU group [102 (90.2%) vs. 62 (50.1%), p < 0.001]. The rate of intrahospital infections was significantly higher in the ICU group while there were no significant differences in the length of hospital stay between the groups. The ICU group exhibited significant increases in D-dimer, NLR, and NEWS values, accompanied by a significant decrease in the SaO2/FiO2 ratio. The multivariable COX proportional regression analysis identified malignancy, higher levels of 4C Mortality Score and NEWS2 as significant predictors of mortality. Conclusion: High-Flow Nasal Cannula oxygen therapy is a safe type of respiratory support in patients with COVID-19 pneumonia and acute hypoxemic respiratory failure with significantly less possibility for emergence of intrahospital infections. In 52% of patients, HFNC was successful in treating AHRF in COVID-19 patients. Overall, mortality in COVID-19 pneumonia with AHRF is still very high, especially in patients treated with noninvasive/invasive mechanical ventilation.

Effects of high-flow nasal cannula oxygen therapy for patients with acute exacerbation of chronic obstructive pulmonary disease in combination with type II respiratory failure.

OBJECTIVE: To evaluate the therapeutic effects of high-flow nasal cannula (HFNC) oxygen therapy in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and type II respiratory failure. METHODS: Seventy-two patients with AECOPD and type II respiratory failure were randomly allocated to an HFNC oxygen therapy trial group or a non-invasive positive-pressure ventilator therapy (NIPPV) control group. Their arterial blood gas parameters and comfort, evaluated using a questionnaire, were compared before and after the therapeutic interventions. RESULTS: The PaCO2 and blood HCO3- concentration of both groups were significantly reduced by the treatments, whereas the pH, PaO2 and PaO2/FiO2 were increased. The PaCO2 of the experimental group was significantly lower than that of the control group following treatment. The PaO2 of the experimental group was significantly higher than that of the control group. The tracheal intubation rates of the two groups did not significantly differ. After treatment, all the indices of comfort were rated higher in the HFNC group than in the NIPPV group. CONCLUSIONS: HFNC has a good therapeutic effect in patients with AECOPD and type II respiratory failure. It improves patient comfort and has clinical value.

High-flow nasal cannula oxygen therapy is superior to conventional oxygen therapy in intensive care unit patients after extubation.

BACKGROUND: Optimal oxygen supply is the cornerstone of the management of critically ill patients after extubation. High flow oxygen system is an alternative to standard oxygen therapy. This research explored the efficacy of high-flow nasal cannula (HFNC) oxygen therapy in patients after extubation in the intensive care unit (ICU). METHOD: We retrospectively analyzed critically ill patients admitted to the ICU and subjected to HFNC or conventional oxygen therapy from January 2018 to June 2022 at the Suzhou Hospital of Integrated Traditional Chinese and Western Medicine. Blood gas analysis, a cough and sputum assessment, and cardiovascular function examinations were performed to evaluate the effect of HFNC oxygen therapy on patients. Also, the 28-d mortality rate, reintubation rate and incidence of respiratory failure were analyzed to evaluate whether HFNC oxygen therapy could improve patients' outcome. RESULTS: In patients who received HFNC oxygen therapy, the partial pressure of oxygen and oxygenation index increased, and the respiratory rate decreased. HFNC oxygen therapy improved the patients' ability to cough up sputum and promoted the expulsion of sputum. In terms of cardiovascular function, patients who received HFNC oxygen therapy had a significant improvement in heart rate, but there was no real effect on patients' arterial pressure. There was no significant difference in the rates of reintubation (P = 0.202), 28-d mortality (P = 0.558) or respiratory failure (P = 0.677) between patients who received different oxygen therapies including HFNC oxygen therapy. CONCLUSION: HFNC oxygen therapy improves the respiratory function of patients after extubation in their ICU and improves their coughing ability.

High-Flow Nasal Cannula Oxygen Therapy versus Non-Invasive Ventilation in AIDS Patients with Acute Respiratory Failure: A Randomized Controlled Trial.

BACKGROUND: Acute respiratory failure (ARF) remains the most common diagnosis for intensive care unit (ICU) admission in acquired immunodeficiency syndrome (AIDS) patients. METHODS: We conducted a single-center, prospective, open-labeled, randomized controlled trial at the ICU, Beijing Ditan Hospital, China. AIDS patients with ARF were enrolled and randomly assigned in a 1:1 ratio to receive either high-flow nasal cannula (HFNC) oxygen therapy or non-invasive ventilation (NIV) immediately after randomization. The primary outcome was the need for endotracheal intubation on day 28. RESULTS: 120 AIDS patients were enrolled and 56 patients in the HFNC group and 57 patients in the NIV group after secondary exclusion. Pneumocystis pneumonia (PCP) was the main etiology for ARF (94.7%). The intubation rates on day 28 were similar to HFNC and NIV (28.6% vs. 35.1%, p = 0.457). Kaplan-Meier curves showed no statistical difference in cumulative intubation rates between the two groups (log-rank test 0.401, p = 0.527). The number of airway care interventions in the HFNC group was fewer than in the NIV group (6 (5-7) vs. 8 (6-9), p < 0.001). The rate of intolerance in the HFNC group was lower than in the NIV group (1.8% vs. 14.0%, p = 0.032). The VAS scores of device discomfort in the HFNC group were lower than that in the NIV group at 2 h (4 (4-5) vs. 5 (4-7), p = 0.042) and at 24 h (4 (3-4) vs. 4 (3-6), p = 0.036). The respiratory rate in the HFNC group was lower than that in the NIV group at 24 h (25 ± 4/min vs. 27 ± 5/min, p = 0.041). CONCLUSIONS: Among AIDS patients with ARF, there was no statistical significance of the intubation rate between HFNC and NIV. HFNC had better tolerance and device comfort, fewer airway care interventions, and a lower respiratory rate than NIV. CLINICAL TRIAL NUMBER: Chictr.org (ChiCTR1900022241).

Early clinical application and prediction of ROX index in patients with high-flow nasal canula oxygen therapy / 中华危重病急救医学

Objective:To investigate the application value of ROX index in evaluating the effect of high-flow nasal cannula oxygen therapy (HFNC) on patients diagnosed with respiratory failure, and to find a simpler and more effective method to observe the efficacy of HFNC.Methods:A retrospective cohort study was conducted. Patients who were admitted to department of critical care medicine of the Tianjin Third Central Hospital from April 2020 to August 2022, diagnosed with type Ⅰ respiratory failure, and treated with HFNC after failure of conventional oxygen therapy were enrolled. Oxygenation index (PaO 2/FiO 2), fraction of inspired oxygen (FiO 2), gas flow rate at the initial time of admission, and pulse oxygen saturation (SpO 2), FiO 2 and respiratory rate (RR) at 2, 4, 6, 8, 10 and 12 hours of HFNC were collected, and ROX index was calculated. The patients with symptoms and PaO 2/FiO 2 improved after HFNC treatment and without higher respiratory support lately were defined as HFNC success, while other patients with symptoms worsening and needing follow-up non-invasive positive pressure ventilation (NIPPV) or invasive positive pressure ventilation (IPPV) were defined as HFNC failure. The tendency of changes in the ROX index at each time point was observed. Receiver operator characteristic curve (ROC curve) was plotted to obtain the optimum cut-off value of ROX index for predicting HFNC outcome and the optimal monitoring time point for HFNC. Results:A total of 142 patients were eventually enrolled, among whom 96 patients (67.61%) were in treated with HFNC successfully, while 46 patients (32.39%) were recorded as HFNC failure (39 patients and 7 patients received NIPPV or IPPV, respectively), with an overall intubation rate of 4.93% (7/142). Compared with the HFNC success group, the HFNC failure group had lower PaO 2/FiO 2 [mmHg (1 mmHg ≈ 0.133 kPa): 208.8±37.3 vs. 235.7±48.3, P < 0.01] and higher initial gas flow rate (L/min: 46.4±3.9 vs. 42.3±4.9, P < 0.01). However, there was no significant difference in gender, age, primary diagnosis, severity of disease, hemoglobin (Hb), C-reactive protein (CRP), and brain natriuretic peptide (BNP) between the two groups. In the HFNC failure group, there were 12 patients (26.09%) received progressive oxygen therapy within 12 hours of HFNC, of which 3 patients (6.52%) occurred within 6 hours, while the other 9 patients (19.57%) occurred after 6 hours. The initial ROX index was not statistically significant between the two groups. Both groups showed a continuous increasing ROX index with longer treatment duration of HFNC, and the ROX index at all of the time points of the HFNC failure group was significantly lower than that of the HFNC success group with statistically significant difference (2 hours: 9.39±2.85 vs. 10.91±3.51, 4 hours: 8.62±2.29 vs. 11.40±3.18, 6 hours: 7.62±1.65 vs. 11.85±3.45, 8 hours: 7.79±1.59 vs. 11.62±3.10, 10 hours: 7.97±1.62 vs. 12.44±2.75, 12 hours: 8.84±2.51 vs. 12.45±3.03, all P < 0.05). The ROC curve analysis showed that the areas under the ROC curve (AUC) of ROX index assessing the effect of HFNC at the time of treating 6, 8 and 10 hours were better than 2, 4 and 12 hours (0.890, 0.903, 0.930 vs. 0.585, 0.738 and 0.829), indicating that the ROX index could determine the efficacy at the early stage of HFNC (within 6 hours). When the optimum cut-off value of ROX index was 8.78, the sensitivity was 90.6%, and the specificity was 76.5%. Conclusion:The ROX index at 6 hours of HFNC has a certain predictive value for the efficacy of HFNC with an optimum cut-off value of 8.78, which can provide clinical health care personnel a method for observing the efficacy of HFNC, and guide the correct selection of oxygen therapy modality at an early stage and timely adjustment of oxygen therapy strategy.

Applications of different flow rates of humidified high flow nasal cannula oxygen therapy on ICU patients with difficult weaning / 中国实用护理杂志

Objective:To explore the effects of different initial flow rates of humidified high flow nasal cannula oxygen therapy on weaning outcomes and comfort level among ICU patients with difficult weaning.Methods:A total of 99 ICU patients with difficult weaning received at Guangzhou Red Cross Hospital ICU from June 2019 to June 2021 were enrolled in the present study, they were assigned to 40 L/min group, 50 L/min group and 60 L/min group according to the random number table method, with 33 cases in each group. The weaning outcomes among three groups were compared, the degree of dryness of oral/nasal cavity, throat pain as well as vital signs and blood gas indexes were also compared before extubation and 30 min after the first humidified high flow nasal cannula (HHFNC) oxygen therapy.Results:There was no significant difference in length of stay in ICU and hospital, re-intubation within 7 days, the mortality within 28 days in ICU and the hospital among three groups ( P>0.05). The weaning success rate were 78.8% (24/33) and 77.4% (23/31) in 50 L/min group and 60 L/min, higher than in the 40 L/min group 53.1% (17/32), the difference was statistically significant ( χ2=4.78, 4.09, both P<0.05). After oxygen therapy, the scores of dryness of oral/nasal cavity and throat pain in the 40 L/min group, 50 L/min group and 60 L/min group were (3.16 ± 0.77), (2.94 ± 0.80) and (3.27 ± 0.92), (3.09 ± 0.77), and (4.10 ± 1.01), (3.97 ± 1.40), the differences were statistically significant ( F=5.21, 9.26, both P<0.05), and the differences between 50 L/min group and 40 L/min group and 60 L/min group were statistically significant ( t values were 2.62-3.99, all P<0.05). However, there was no significant difference in vital signs and blood gas indexes among the three groups before extubation and after oxygen therapy ( P>0.05). Conclusions:Humidified high flow nasal cannula oxygen therapy for the ICU patients with difficult weaning, oxygen flow with 50L/min can not only effectively promote weaning success rate but also improve patients′ respiratory comfort level.

High-flow nasal cannula oxygen therapy versus non-invasive ventilation for chronic obstructive pulmonary diseases with acute-moderate hypercapnic respiratory failure: a randomized controlled trial of non-inferiority / 中华急诊医学杂志

Objective:To compare the efficacy of high-flow nasal cannula oxygen therapy (HFNC) and non-invasive ventilation (NIV) in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) with moderate typeⅡ respiratory failure, to clarify the feasibility of HFNC in the treatment of AECOPD, and to explore the influencing factors of HFNC failure.Methods:This study was a randomized controlled trial of non-inferiority. Patients with AECOPD with moderate type Ⅱ respiratory failure [arterial blood gas pH 7.25-7.35, partial pressure of arterial blood carbon dioxide (PaCO 2)> 50 mmHg] admitted to the Intensive Care Unit (ICU) from January 2018 to December 2021 were randomly assigned to the HFNC group and NIV group to receive respiratory support. The primary endpoint was the treatment failure rate. The secondary endpoints were blood gas analysis and vital signs at 1 h, 12 h, and 48 h, total duration of respiratory support, 28-day mortality, comfort score, ICU length of stay, and total length of stay. Multivariate logistic regression analysis was used to evaluate the failure factors of HFNC treatment. Results:Totally 228 patients were randomly divided into two groups, 108 patients in the HFNC group and 110 patients in the NIV group. The treatment failure rate was 29.6% in the HFNC group and 25.5% in the NIV group. The risk difference of failure rate between the two groups was 4.18% (95% CI: -8.27%~16.48%, P=0.490), which was lower than the non-inferiority value of 9%. The most common causes of failure in the HFNC group were carbon dioxide retention and aggravation of respiratory distress, and the most common causes of failure in the NIV group were treatment intolerance and aggravation of respiratory distress. Treatment intolerance in the HFNC group was significantly lower than that in the NIV group (-29.02%, 95% CI -49.52%~-7.49%; P=0.004). After 1 h of treatment, the pH in both groups increased significantly, PaCO 2 decreased significantly and the oxygenation index increased significantly compared with baseline (all P < 0.05). PaCO 2 in both groups decreased gradually at 1 h, 12 h and 48 h after treatment, and the pH gradually increased. The average number of daily airway care interventions and the incidence of nasal and facial lesions in the HFNC group were significantly lower than those in the NIV group ( P < 0.05), while the comfort score in the HFNC group was significantly higher than that in the NIV group ( P=0.021). There was no significant difference between the two groups in the total duration of respiratory support, dyspnea score, ICU length of stay, total length of stay and 28-day mortality (all P > 0.05). Multivariate logistic regression analysis showed that acute physiology and chronic health evaluation Ⅱ score (≥15), family NIV, history of cerebrovascular accident, PaCO 2 (≥60 mmHg) and respiratory rate (≥32 times/min) at 1 h were independent predictors of HFNC failure. Conclusions:HFNC is not inferior to NIV in the treatment of AECOPD complicated with moderate type Ⅱ respiratory failure. HFNC is an ideal choice of respiratory support for patients with NIV intolerance, but clinical application should pay attention to the influencing factors of its treatment failure.

Use of high-flow nasal cannula oxygen and risk factors for high-flow nasal cannula oxygen failure in critically-ill patients with COVID-19.

BACKGROUND: High-flow nasal oxygen therapy (HFNC) may be an attractive first-line ventilatory support in COVID-19 patients. However, HNFC use for the management of COVID-19 patients and risk factors for HFNC failure remain to be determined. METHODS: In this retrospective study, we included all consecutive COVID-19 patients admitted to our intensive care unit (ICU) in the first (Mars-May 2020) and second (August 2020- February 202) French pandemic waves. Patients with limitations for intubation were excluded. HFNC failure was defined as the need for intubation after ICU admission. The impact of HFNC use was analyzed in the whole cohort and after constructing a propensity score. Risk factors for HNFC failure were identified through a landmark time-dependent cause-specific Cox model. The ability of the 6-h ROX index to detect HFNC failure was assessed by generating receiver operating characteristic (ROC) curve. RESULTS: 200 patients were included: HFNC was used in 114(57%) patients, non-invasive ventilation in 25(12%) patients and 145(72%) patients were intubated with a median delay of 0 (0-2) days after ICU admission. Overall, 78(68%) patients had HFNC failure. Patients with HFNC failure had a higher ICU mortality rate (34 vs. 11%, p = 0.02) than those without. At landmark time of 48 and 72 h, SAPS-2 score, extent of CT-Scan abnormalities > 75% and HFNC duration (cause specific hazard ratio (CSH) = 0.11, 95% CI (0.04-0.28), per + 1 day, p < 0.001 at 48 h and CSH = 0.06, 95% CI (0.02-0.23), per + 1 day, p < 0.001 at 72 h) were associated with HFNC failure. The 6-h ROX index was lower in patients with HFNC failure but could not reliably predicted HFNC failure with an area under ROC curve of 0.65 (95% CI(0.52-0.78), p = 0.02). In the matched cohort, HFNC use was associated with a lower risk of intubation (CSH = 0.32, 95% CI (0.19-0.57), p < 0.001). CONCLUSIONS: In critically-ill COVID-19 patients, while HFNC use as first-line ventilatory support was associated with a lower risk of intubation, more than half of patients had HFNC failure. Risk factors for HFNC failure were SAPS-2 score and extent of CT-Scan abnormalities > 75%. The risk of HFNC failure could not be predicted by the 6-h ROX index but decreased after a 48-h HFNC duration.

High-flow nasal cannula versus continuous positive airway pressure in primary respiratory support for preterm infants: A systematic review and meta-analysis.

Respiratory support is crucial for the survival of preterm infants, and High-flow Nasal Cannula Oxygen Therapy (HFNC) and Continuous Positive Airway Pressure (CPAP) are commonly used for neonatal respiratory support. This meta-analysis aimed to compare the effects of HFNC and CPAP in primary respiratory support for preterm infants, to provide evidence-based support for clinical practice. PubMed, Embase, Cochrane Library, ClinicalTrials.gov, CNKI, VIP, WANFANG and SinoMed were searched for eligible studies. The primary outcomes included the incidence of treatment failure and the application of mechanical ventilation. A total of 27 eligible studies with 3,351 participants were included. There was no significant difference in the incidence of respiratory support failure [RR = 1.17, 95%CI (0.88-1.56)] and the application of mechanical ventilation [RR = 1.00, 95%CI (0.84-1.19)] between HFNC group and CPAP group. HFNC resulted in lower rate of air leaks [RR = 0.65, 95%CI (0.46-0.92)], nasal trauma [RR = 0.36, 95%CI (0.29-0.45)] and abdominal distension [RR = 0.39, 95%CI (0.27-0.58)], and later time of mechanical ventilation initiating [SMD = 0.60, 95%CI (0.21-0.99)], less duration of oxygen therapy [SMD = -0.35, 95%CI (-0.68 to -0.02)] and earlier enteral feeding [SMD = -0.54, 95%CI (-0.95 to -0.13)]. Alternative non-invasive respiratory support after initial treatment failure resulted in no difference in the application of mechanical ventilation between the two groups [RR = 0.99, 95%CI (0.52-1.88)]. HFNC might be more effective and safer in primary respiratory support for preterm infants. Using CPAP as a remedy for the treatment failure of HFNC could not avoid intubation. For premature infants with the gestational age <28 weeks, HFNC as primary respiratory support still needs to be further elucidated. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022313479, identifier: CRD42022313479.

[Comparison of high-flow nasal cannula oxygen therapy and non-rebreather face mask in the treatment of mild carbon monoxide poisoning].

Objective: To compare the efficacy of high-flow nasal cannula oxygen therapy (HFNC) and non-rebreather face mask (NRFM) in the treatment of mild acute carbon monoxide poisoning (ACOP) in reducing carboxyhemoglobin (COHb) , and to explore the feasibility of HFNC in the treatment of ACOP. Methods: Patients with mild ACOP with COHb >10% who were admitted to the emergency department of Northern Jiangsu People's Hospital from January 2015 to December 2020 were analyzed, and those with altered consciousness, mechanical ventilation and those requiring hyperbaric oxygen therapy were excluded. The patients were divided into HFNC group and NRFM group according to the oxygen therapy used in the emergency department. The COHb decline value and COHb half-life in the two groups were observed. Results: Seventy-one patients were enrolled, including 39 in the NRFM group and 32 in the HFNC group. The baseline COHb in the HFNC group was 24.8%±8.3%, and that in the NRFM group was 22.5%±7.1%, with no significant difference between the two groups (t=1.27, P=0.094) . At 60 min, 90 min and 120 min of treatment, COHb in both groups decreased, but the COHb in HFNC group was lower than that in NRFM group at the same time point (P<0.05) . After 1 h of treatment, the COHb decrease in the HFNC group (16.9%±4.5%) was significantly higher than that in the NRFM group (10.1%±7.8%) (t=4.32, P=0.013) . The mean half-life of COHb in the HFNC group (39.3 min) was significantly lower than that in the NRFM group (61.4 min) (t=4.69, P=0.034) . Conclusion: HFNC treatment of mild ACOP can rapidly reduce blood COHb level, it is a potential oxygen therapy method for clinical treatment of ACOP.

The quality and quantity of sleep on dexmedetomidine during high-flow nasal cannula oxygen therapy in critically ill patients.

Purpose : High-flow nasal cannula oxygen therapy (HFNC) is a new type of non-invasive respiratory support for acute respiratory failure patients. However, patients receiving HFNC often develop sleep disturbances. We therefore examined whether dexmedetomidine could preserve the sleep characteristics in patients who underwent HFNC. Patients and Methods : This was a pilot, randomized controlled study. We assigned critically ill patients treated with HFNC to receive dexmedetomidine (0.2 to 0.7 µg / kg / h, DEX group) or not (non-DEX group) at night (9:00 p.m. to 6:00 a.m.). Polysomnograms were monitored during the study period. The primary outcomes were total sleep time (TST), sleep efficiency and duration of stage 2 non-rapid eye movement (stage N2) sleep. Results : Of the 28 patients who underwent randomization, 24 were included in the final analysis (12 patients per group). Dexmedetomidine increased the TST (369 min vs. 119 min, p = 0.024) and sleep efficiency (68% vs. 22%, P = 0.024). The duration of stage N2 was increased in the DEX group compared with the non-DEX group, but this finding did not reach statistical significance. The incidences of respiratory depression and hemodynamic instability were similar between the two groups. Conclusions : In critically ill patients who underwent HFNC, dexmedetomidine may optimize the sleep quantity without any adverse events. J. Med. Invest. 69 : 266-272, August, 2022.

Effectiveness of high flow nasal cannula oxygen therapy in patients of acute pulmonary thromboembolism with acute hypoxemic respiratory failure.

Background: Acute Pulmonary thromboembolism (PTE) is associated with acute hypoxemic respiratory failure (AHRF), which is a leading cause of death in these patients. High-Flow Nasal Cannula (HFNC) oxygen therapy is a cornerstone of the treatment of respiratory failure. The aim of the present study is to explore the efficacy of HFNC in the treatment of patients of acute PTE with acute hypoxemic respiratory failure in India. Methods: This is a retrospective study of patients admitted to a tertiary care center with acute PTE with AHRF during the period from January 2018 to January 2020. After reviewing medical files, patients of acute PTE with AHRF treated with HFNC were included in the study. We analyzed the improvement in oxygenation parameters and respiratory rate, as well as outcome in these patients. Results: During the above specified period, 12 patients suffering from PTE with AHRF were treated with HFNC. After 1 h of the initiation of HFNC along with anticoagulation, the respiratory parameters of patients significantly improved. HFNC was applied for a period of 6-10 days. None of the patients required intubation for AHRF, and all patients were discharged from the hospital on oral anticoagulants. Conclusion: HFNC oxygen therapy in patients with acute PTE with AHRF showed rapid improvement of oxygenation and respiratory rate. HFNC oxygen therapy is an efficacious treatment for patients with AHRF secondary to acute PTE without any significant hemodynamic effect. It acts as a superior modality of oxygen therapy avoiding noninvasive and invasive ventilatory support.

Analysis of risk factors for the failure of respiratory support with high-flow nasal cannula oxygen therapy in children with acute respiratory dysfunction: A case-control study.

Background: Evidence-based clinical practice guidelines regarding high-flow nasal cannula (HFNC) use for respiratory support in critically ill children are lacking. Therefore, we aimed to determine the risk factors for early HFNC failure to reduce the failure rate and prevent adverse consequences of HFNC failure in children with acute respiratory dysfunction. Methods: Demographic and laboratory data were compared among patients, admitted to the pediatric intensive care unit between January 2017 and December 2018, who were included in a retrospective cohort study. Univariate and multivariate analyses were performed to determine risk factors for eventual entry into the predictive model for early HFNC failure and to perform an external validation study in a prospective observational cohort study from January to February 2019. Further, the association of clinical indices and trends pre- and post-treatment with HFNC treatment success or failure in these patients was dynamically observed. Results: In total, 348 pediatric patients were included, of these 282 (81.0%) were included in the retrospective cohort study; HFNC success was observed in 182 patients (64.5%), HFNC 0-24 h failure in 74 patients (26.2%), and HFNC 24-48 h failure in 26 patients (9.2%). HFNC 24 h failure was significantly associated with the pediatric risk of mortality (PRISM) III score [odds ratio, 1.391; 95% confidence interval (CI): 1.249-1.550], arterial partial pressure of carbon dioxide-to-arterial partial pressure of oxygen (PaCO2/PaO2) ratio (odds ratio, 38.397; 95% CI: 6.410-230.013), and respiratory rate-oxygenation (ROX) index (odds ratio, 0.751; 95% CI: 0.616-0.915). The discriminating cutoff point for the new scoring system based on the three risk factors for HFNC 24 h failure was ≥ 2.0 points, with an area under the receiver operating characteristic curve of 0.794 (95% CI, 0.729-0.859, P < 0.001), sensitivity of 68%, and specificity of 79%; similar values were noted on applying the model to the prospective observational cohort comprising 66 patients (AUC = 0.717, 95% CI, 0.675-0.758, sensitivity 83%, specificity 44%, P = 0.009). In this prospective cohort, 11 patients with HFNC failure had an upward trend in PaCO2/PaO2 ratio and downward trends in respiratory failure index (P/F ratio) and ROX index; however, opposite directions of change were observed in 55 patients with HFNC success. Furthermore, the fractional changes (FCs) in PaCO2/PaO2 ratio, P/F ratio, percutaneous oxygen saturation-to-fraction of inspired oxygen (S/F) ratio, and ROX index at 2 h post-HFNC therapy onset were statistically significant between the two groups (all, P < 0.05). Conclusion: In the pediatric patients with acute respiratory insufficiency, pre-treatment PRISM III score, PaCO2/PaO2 ratio, and ROX index were risk factors for HFNC 24 h failure, and the direction and magnitude of changes in the PaCO2/PaO2 ratio, P/F ratio, and ROX index before and 2 h after HFNC treatment were warning indicators for HFNC 24 h failure. Further close monitoring should be considered for patients with these conditions.

Therapeutic effects and the influence on serum inflammatory factors of high-flow nasal cannula oxygen therapy in senior patients with lower respiratory tract infections.

BACKGROUND: Lower respiratory tract infection (LRTI) is a clinical multi-infectious disease caused by viral, bacterial, and other microbial infections. OBJECTIVE: The present study aims to explore the therapeutic effects of high-flow nasal cannula (HFNC) oxygen therapy and its influence on the serum levels of inflammatory factors in senior patients with LRTI. METHODS: In this randomized controlled trial, 84 senior patients with LRTI were enrolled between March 2017 and December 2019 and divided into the observation group and the control group according to the random number table method, with 42 cases in each group. Conventional nasal cannula (CNC) oxygen therapy was conducted in the control group and HFNC was conducted in the observation group. After 3 days of treatment, sputum properties, sputum volume, sputum viscosity, and sputum crust formation were recorded to determine the clinical efficacy. ELISA was performed to detect the serum levels of tumor necrosis factor alpha (TNF-α) and interlukein (IL)-8 before and after treatment. RESULTS: The total efficacy in the observation group was 92.86%, which was higher than in the control group (73.81%) (P< 0.05). Three days after treatment, the percentage of grade I sputum in the observation group (73.81%) was higher than in the control group (40.48%). Moreover, the percentage of grade II sputum (23.81%), the percentage of grade III sputum (2.38%), together with the sputum crust formation rate in the observation group (4.76%) were all lower than in the control group (45.24, 14.28, and 26.19%, respectively) (P< 0.05). Three days after treatment, the levels of IL-8 (0.21 ± 0.03 pg/L) and TNF-α (1.27 ± 0.14 ng/L) in the observation group were lower than in the control group (0.30 ± 0.04 pg/L, and 1.49 ± 0.18 ng/L) (t= 6.525, 11.665, 6.252, respectively; P< 0.05). CONCLUSION: The application of HFNC in senior patients with LRTI could improve respiratory humidification, reduce the number of sputum aspirations, and improve anti-inflammatory effects. It is worthy of application in elderly patients with LRTI.

[High-flow nasal cannula oxygen therapy in prostate-targeted needle biopsy in high-risk patients with obstructive sleep apnea syndrome].

OBJECTIVE: To compare the effect of high-flow nasal cannula oxygen therapy (HFNC) from that of conventional nasal cannula oxygen therapy (CNC) on oxygenation during prostate-targeted needle biopsy under total intravenous anesthesia in high-risk patients with obstructive sleep apnea syndrome (OSAS). METHODS: We randomly assigned 64 high-risk OSAS patients to two groups of an equal number to receive HFNC and CNC, respectively, under total intravenous anesthesia. We recorded the incidence rates of SpO2<95% and the lowest SpO2 during surgery, the mean arterial pressure (MAP), heart rate (HR) and oxygen saturation (SpO2) upon entering the operation room (T0), at the beginning (T1) and the end of surgery (T2) and at 30 minutes postoperatively (T3), as well as arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2) at T0 and T2, and the incidence rates of airway intervention and adverse events, followed by comparison of the parameters between the two groups. RESULTS: Both the lowest SpO2 and PaO2 were significantly increased in the HFNC group compared with those in the CNC group (P < 0.05) while no statistically significant difference was observed in PaCO2 between the two groups (P > 0.05). The intraoperative incidence rates of hypoxia, airway intervention, choking and body movement were remarkably lower in the HFNC than in the CNC group (P < 0.05), but there were no statistically significant differences in the operation time, anesthesia duration and propofol dosage between the two groups (P > 0.05). CONCLUSION: HFNC may provide more adequate oxygenation, improve airway management, and reduce the incidence of hypoxemia in high-risk OSAS patients during prostate biopsy under total intravenous anesthesia.