Chronic Neuromuscular Respiratory Failure and Home Assisted Ventilation.

Chronic respiratory failure is a common, important complication of many types of neuromuscular and chest wall disorders. While the pathophysiology of each disease may be different, these disorders can variably affect all muscles involved in breathing, including inspiratory, expiratory, and bulbar muscles, ultimately leading to chronic respiratory failure and hypoventilation. The use of home assisted ventilation through noninvasive interfaces aims to improve the symptoms of hypoventilation, improve sleep quality, and, when possible, improve mortality. An increasing variety of interfaces has allowed for improved comfort and compliance. In a minority of scenarios, noninvasive ventilation is either not appropriate or no longer effective due to disease progression, and a transition to tracheal ventilation should be considered.

Prognosis of mechanically ventilated patients with COVID-19 after failure of high-flow nasal cannula: a retrospective cohort study.

BACKGROUND: There is an argument whether the delayed intubation aggravate the respiratory failure in Acute respiratory distress syndrome (ARDS) patients with coronavirus disease 2019 (COVID-19). We aimed to investigate the effect of high-flow nasal cannula (HFNC) failure before mechanical ventilation on clinical outcomes in mechanically ventilated patients with COVID-19. METHODS: This retrospective cohort study included mechanically ventilated patients who were diagnosed with COVID-19 and admitted to the intensive care unit (ICU) between February 2020 and December 2021 at Asan Medical Center. The patients were divided into HFNC failure (HFNC-F) and mechanical ventilation (MV) groups according to the use of HFNC before MV. The primary outcome of this study was to compare the worst values of ventilator parameters from day 1 to day 3 after mechanical ventilation between the two groups. RESULTS: Overall, 158 mechanically ventilated patients with COVID-19 were included in this study: 107 patients (67.7%) in the HFNC-F group and 51 (32.3%) in the MV group. The two groups had similar profiles of ventilator parameter from day 1 to day 3 after mechanical ventilation, except of dynamic compliance on day 3 (28.38 mL/cmH2O in MV vs. 30.67 mL/H2O in HFNC-F, p = 0.032). In addition, the HFNC-F group (5.6%) had a lower rate of ECMO at 28 days than the MV group (17.6%), even after adjustment (adjusted hazard ratio, 0.30; 95% confidence interval, 0.11-0.83; p = 0.045). CONCLUSIONS: Among mechanically ventilated COVID-19 patients, HFNC failure before mechanical ventilation was not associated with deterioration of respiratory failure.

Effect of noninvasive ventilation on mortality and clinical outcomes among patients with severe hypoxemic COVID-19 pneumonia after high-flow nasal oxygen failure: a multicenter retrospective French cohort with propensity score analysis.

BACKGROUND: We assessed the effect of noninvasive ventilation (NIV) on mortality and length of stay after high flow nasal oxygenation (HFNO) failure among patients with severe hypoxemic COVID-19 pneumonia. METHODS: In this multicenter, retrospective study, we enrolled COVID-19 patients admitted in intensive care unit (ICU) for severe COVID-19 pneumonia with a HFNO failure from December 2020 to January 2022. The primary outcome was to compare the 90-day mortality between patients who required a straight intubation after HFNO failure and patients who received NIV after HFNO failure. Secondary outcomes included ICU and hospital length of stay. A propensity score analysis was performed to control for confounding factors between groups. Exploratory outcomes included a subgroup analysis for 90-day mortality. RESULTS: We included 461 patients with HFNO failure in the analysis, 233 patients in the straight intubation group and 228 in the NIV group. The 90-day mortality did not significantly differ between groups, 58/228 (25.4%) int the NIV group compared with 59/233 (25.3%) in the straight intubation group, with an adjusted hazard ratio (HR) after propensity score weighting of 0.82 [95%CI, 0.50-1.35] (p = 0.434). ICU length of stay was significantly shorter in the NIV group compared to the straight intubation group, 10.0 days [IQR, 7.0-19.8] versus 18.0 days [IQR,11.0-31.0] with a propensity score weighted HR of 1.77 [95%CI, 1.29-2.43] (p < 0.001). A subgroup analysis showed a significant increase in mortality rate for intubated patients in the NIV group with 56/122 (45.9%), compared to 59/233 (25.3%) for patients in the straight intubation group (p < 0.001). CONCLUSIONS: In severely hypoxemic COVID-19 patients, no significant differences were observed on 90-day mortality between patients receiving straight intubation and those receiving NIV after HFNO failure. NIV strategy was associated with a significant reduction in ICU length of stay, despite an increase in mortality in the subgroup of patients finally intubated.

Initiation of noninvasive ventilation in patients with amyotrophic lateral sclerosis.

INTRODUCTION/AIMS: Noninvasive ventilation (NIV) has been shown to improve survival and symptom burden in patients with amyotrophic lateral sclerosis (ALS). However, limited data exist regarding the clinical and physiological parameters at the time of NIV initiation. This study aimed to describe the clinical characteristics and respiratory physiological markers in a cohort of ALS patients with chronic respiratory failure. METHODS: This is a single-center retrospective cohort study of patients with ALS assessed for NIV initiation between February 2012 and January 2021. NIV was initiated based on insurance eligibility criteria: daytime hypercapnia, defined by partial pressure of carbon dioxide (PaCO2) >45 mm Hg using diurnal transcutaneous CO2 (TcCO2) as a surrogate, a maximal inspiratory pressure (MIP) <60 cmH2O or forced vital capacity (FVC) <50% predicted normal. RESULTS: We identified 335 patients with ALS and chronic respiratory failure referred to an outpatient home ventilation clinic for NIV initiation. The mean age was 64 years ±11; 151 (45%) were female, 326 (97%) were white, and 100 (29%) had bulbar-onset ALS. At the time of NIV initiation, the mean FVC was 64% ± 19%, the mean MIP; 41 cmH2O ± 17, and diurnal TcCO2; 40 ± 6 mmHg. The most common reasons for NIV initiation were MIP <60 cmH2O (58%) and multiple concomitant indications (28%). Within 1 year of NIV initiation, 126 (37%) patients were deceased. DISCUSSION: We found that impairment in inspiratory force was the most common reason for NIV initiation and often preceded significant declines in FVC.

Performance of newly developed add-on devices on aerosol delivery in noninvasive ventilated subjects.

Background: Several techniques had been developed to generate aerosolized medications during noninvasive ventilation (NIV) using variable inhalation methods. This study hypothesized that large spacers were more efficient significantly than small spacers and adapters during NIV. Objective: The main objective of this study was to compare the performance of newly developed spacers with standard T-piece in NIV chronic obstructive pulmonary disease (COPD) subjects. Methods: Sixty COPD subjects requiring NIV were included in this study. A dual-limb circuit was used, and the mode of ventilator was set in spontaneous volume-controlled mode. Dual-limb ventilation circuit, consists of inspiratory-limb and expiratory-limb, is pressure and volume controlled in response to subject expiration providing relatively high resistance to expiratory flow. Two experimental sets were evaluated: the first was introducing two preliminary pressurized metered-dose inhalers (pMDI) puffs before the nebulization of 1 ml of a respirable solution of salbutamol by vibrating mesh nebulizer (VMN) using Minimhal and Combihaler. The second was to only nebulize 1 ml of salbutamol respirable solution by VMN using Combihaler, Minimhal, and standard T-piece. Two urine samples were collected after aerosol delivery: urine sample after 30 min. (USAL0.5) as an indicator of lung deposition and all urine pooled 24 h (USAL24) post-inhalation as an indicator of systemic absorption. The amount of salbutamol extracted from urine samples was assayed by high-performance liquid chromatography. Results: Minimhal + pMDI + VMN delivered a higher percentage of salbutamol 30 min post-inhalation than Minimhal + VMN (p < 0.001). Also, Combihaler + pMDI + VMN delivered a higher percentage of salbutamol 30 min post-inhalation than Combihaler + VMN (p < 0.001). Combihaler + VMN delivered a higher percentage of salbutamol 30 min and 24 h post-inhalation than both Minimhal + VMN and T-piece + VMN (p < 0.001). Standard T-piece delivered the lowest aerosol amount delivered to the lung compared to both spacers (p < 0.05). Conclusions: Introducing two pMDI puffs significantly improved aerosol delivery by both spacers. Combihaler significantly improves aerosol delivery more than Minimhal.

Implications of sedation during the use of noninvasive ventilation in children with acute respiratory failure (SEDANIV Study).

BACKGROUND: The objective of this study was to analyze the effects of sedation administration on clinical parameters, comfort status, intubation requirements, and the pediatric intensive care unit (PICU) length of stay (LOS) in children with acute respiratory failure (ARF) receiving noninvasive ventilation (NIV). METHODS: Thirteen PICUs in Spain participated in a prospective, multicenter, observational trial from January to December 2021. Children with ARF under the age of five who were receiving NIV were included. Clinical information and comfort levels were documented at the time of NIV initiation, as well as at 3, 6, 12, 24, and 48 h. The COMFORT-behavior (COMFORT-B) scale was used to assess the patients' level of comfort. NIV failure was considered to be a requirement for endotracheal intubation. RESULTS: A total of 457 patients were included, with a median age of 3.3 months (IQR 1.3-16.1). Two hundred and thirteen children (46.6%) received sedation (sedation group); these patients had a higher heart rate, higher COMFORT-B score, and lower SpO2/FiO2 ratio than did those who did not receive sedation (non-sedation group). A significantly greater improvement in the COMFORT-B score at 3, 6, 12, and 24 h, heart rate at 6 and 12 h, and SpO2/FiO2 ratio at 6 h was observed in the sedation group. Overall, the NIV success rate was 95.6%-intubation was required in 6.1% of the sedation group and in 2.9% of the other group (p = 0.092). Multivariate analysis revealed that the PRISM III score at NIV initiation (OR 1.408; 95% CI 1.230-1.611) and respiratory rate at 3 h (OR 1.043; 95% CI 1.009-1.079) were found to be independent predictors of NIV failure. The PICU LOS was correlated with weight, PRISM III score, respiratory rate at 12 h, SpO2 at 3 h, FiO2 at 12 h, NIV failure and NIV duration. Sedation use was not found to be independently related to NIV failure or to the PICU LOS. CONCLUSIONS: Sedation use may be useful in children with ARF treated with NIV, as it seems to improve clinical parameters and comfort status but may not increase the NIV failure rate or PICU LOS, even though sedated children were more severe at technique initiation in the present sample.

High-flow nasal oxygen versus conventional oxygen therapy and noninvasive ventilation in COVID-19 respiratory failure: a systematic review and network meta-analysis of randomised controlled trials.

BACKGROUND: Noninvasive methods of respiratory support, including noninvasive ventilation (NIV), continuous positive airway pressure (CPAP), and high-flow nasal oxygen (HFNO), are potential strategies to prevent progression to requirement for invasive mechanical ventilation in acute hypoxaemic respiratory failure. The COVID-19 pandemic provided an opportunity to understand the utility of noninvasive respiratory support among a homogeneous cohort of patients with contemporary management of acute respiratory distress syndrome. We performed a network meta-analysis of studies evaluating the efficacy of NIV (including CPAP) and HFNO, compared with conventional oxygen therapy (COT), in patients with COVID-19. METHODS: PubMed, Embase, and the Cochrane library were searched in May 2023. Standard random-effects meta-analysis was used first to estimate all direct pairwise associations and the results from all studies were combined using frequentist network meta-analysis. Primary outcome was treatment failure, defined as discontinuation of HFNO, NIV, or COT despite progressive disease. Secondary outcome was mortality. RESULTS: We included data from eight RCTs with 2302 patients, (756 [33%] assigned to COT, 371 [16%] to NIV, and 1175 [51%] to HFNO). The odds of treatment failure were similar for NIV (P=0.33) and HFNO (P=0.25), and both were similar to that for COT (reference category). The odds of mortality were similar for all three treatments (odds ratio for NIV vs COT: 1.06 [0.46-2.44] and HFNO vs COT: 0.97 [0.57-1.65]). CONCLUSIONS: Noninvasive ventilation, high-flow nasal oxygen, and conventional oxygen therapy are comparable with regards to treatment failure and mortality in COVID-19-associated acute respiratory failure. PROSPERO REGISTRATION: CRD42023426495.

Noninvasive Ventilation in the Cardiac Intensive Care Unit.

Over the last several decades, the cardiac intensive care unit (CICU) has seen an increase in the complexity of the patient population and etiologies requiring CICU admission. Currently, respiratory failure is the most common reason for admission to the contemporary CICU. As a result, noninvasive ventilation (NIV), including noninvasive positive-pressure ventilation and high-flow nasal cannula, has been increasingly utilized in the management of patients admitted to the CICU. In this review, we detail the different NIV modalities and summarize the evidence supporting their use in conditions frequently encountered in the CICU. We describe the unique pathophysiologic interactions between positive pressure ventilation and left and/or right ventricular dysfunction. Additionally, we discuss the evidence and strategies for utilization of NIV as a method to reduce extubation failure in patients who required invasive mechanical ventilation. Lastly, we examine unique considerations for managing respiratory failure in certain, high-risk patient populations such as those with right ventricular failure, severe valvular disease, and adult congenital heart disease. Overall, it is critical for clinicians who practice in the CICU to be experts with the application, risks, benefits, and modalities of NIV in cardiac patients with respiratory failure.

Deventilation Syndrome in Patients with Chronic Obstructive Pulmonary Disease Using Nocturnal Noninvasive Ventilation: What Are the Underlying Mechanisms?

INTRODUCTION: Patients with chronic obstructive pulmonary disease (COPD) commonly experience severe dyspnea after discontinuation of nocturnal noninvasive ventilation (NIV), known as deventilation syndrome (DVS), which negatively affects quality of life. Despite various hypotheses, the precise mechanisms of DVS remain unknown. METHODS: An observational pilot study was performed monitoring 16 stable COPD patients before, during, and after an afternoon nap on NIV. Seven patients experienced DVS (Borg Dyspnea Scale ≥5), while nine served as controls (Borg Dyspnea Scale ≤2). Hyperinflation was evaluated through inspiratory capacity (IC) measurements and end-expiratory lung impedance (EELI) via electrical impedance tomography. Respiratory muscle activity was assessed by diaphragmatic surface electromyography (sEMG). RESULTS: Post-NIV dyspnea scores were significantly higher in the DVS group (5 [3-7] vs. 0 [0-1.5], p < 0.001). IC values were lower in the DVS group compared to controls, both pre-NIV (54 [41-63] vs. 88 [72-94] %pred., p = 0.006) and post-NIV (45 [40-59] vs. 76 [65-82] %pred., p = 0.005), while no intergroup difference was seen in IC changes pre- and post-NIV. EELI values after NIV indicated a tendency towards lower values in controls and higher values in DVS patients. sEMG amplitudes were higher in the DVS group within the first 5-min post-NIV (221 [112-294] vs. 100 [58-177]% of baseline, p = 0.030). CONCLUSION: This study suggests that it is unlikely that DVS originates from the inability to create diaphragmatic muscle activity after NIV. Instead, NIV-induced hyperinflation in individuals with static hyperinflation may play a significant role. Addressing hyperinflation holds promise in preventing DVS symptoms in COPD patients.

Respective Effects of Helmet Pressure Support, Continuous Positive Airway Pressure, and Nasal High-Flow in Hypoxemic Respiratory Failure: A Randomized Crossover Clinical Trial.

Rationale: The respective effects of positive end-expiratory pressure (PEEP) and pressure support delivered through the helmet interface in patients with hypoxemia need to be better understood. Objectives: To assess the respective effects of helmet pressure support (noninvasive ventilation [NIV]) and continuous positive airway pressure (CPAP) compared with high-flow nasal oxygen (HFNO) on effort to breathe, lung inflation, and gas exchange in patients with hypoxemia (PaO2/FiO2 ⩽ 200). Methods: Fifteen patients underwent 1-hour phases (constant FiO2) of HFNO (60 L/min), helmet NIV (PEEP = 14 cm H2O, pressure support = 12 cm H2O), and CPAP (PEEP = 14 cm H2O) in randomized sequence. Measurements and Main Results: Inspiratory esophageal (ΔPES) and transpulmonary pressure (ΔPL) swings were used as surrogates for inspiratory effort and lung distension, respectively. Tidal Volume (Vt) and end-expiratory lung volume were assessed with electrical impedance tomography. ΔPES was lower during NIV versus CPAP and HFNO (median [interquartile range], 5 [3-9] cm H2O vs. 13 [10-19] cm H2O vs. 10 [8-13] cm H2O; P = 0.001 and P = 0.01). ΔPL was not statistically different between treatments. PaO2/FiO2 ratio was significantly higher during NIV and CPAP versus HFNO (166 [136-215] and 175 [158-281] vs. 120 [107-149]; P = 0.002 and P = 0.001). NIV and CPAP similarly increased Vt versus HFNO (mean change, 70% [95% confidence interval (CI), 17-122%], P = 0.02; 93% [95% CI, 30-155%], P = 0.002) and end-expiratory lung volume (mean change, 198% [95% CI, 67-330%], P = 0.001; 263% [95% CI, 121-407%], P = 0.001), mostly due to increased aeration/ventilation in dorsal lung regions. During HFNO, 14 of 15 patients had pendelluft involving >10% of Vt; pendelluft was mitigated by CPAP and further by NIV. Conclusions: Compared with HFNO, helmet NIV, but not CPAP, reduced ΔPES. CPAP and NIV similarly increased oxygenation, end-expiratory lung volume, and Vt, without affecting ΔPL. NIV, and to a lesser extent CPAP, mitigated pendelluft. Clinical trial registered with clinicaltrials.gov (NCT04241861).

Management of sleep-disordered breathing in patients with syndromic hemifacial macrosomia.

PURPOSE: Patients with syndromic hemifacial microsomia (SHFM) are at risk of obstructive sleep apnea (OSA). The aim of the study was to describe the prevalence of OSA and its management, especially in patients with Goldenhar syndrome (GS). METHODS: The respiratory polygraphies and clinical management of 15 patients, aged 2 to 23 years, evaluated at a national reference center, were analyzed. RESULTS: Four (27%) patients had no OSA, 4 (27%) had mild OSA, and 7 (46%), of whom 5 were ≤ 2 years old, had severe OSA. None of the patients had central apneas. Only one patient had alveolar hypoventilation, and another one had nocturnal hypoxemia. Two patients had severe OSA despite prior adenoidectomy or mandibular distraction osteogenesis. Median duration of follow-up was 3.5 years (range 0.5-9 years). None of the patients without OSA or with mild OSA at baseline respiratory polygraphy developed OSA during the follow up. Among the 7 patients with severe OSA, 3 required continuous positive airway pressure or noninvasive ventilation, and one patient required a tracheostomy. CONCLUSION: In conclusion, patients with SHFM are at high risk of severe OSA at any age, underlining the importance of systematic sleep studies to diagnose and evaluate the severity of OSA. Individualized treatment should be privileged, based on a careful examination of the entire upper airway, taking in account potential associated risk factors. All patients with SHFM should be managed by a pediatric expert multidisciplinary medical/surgical team until the end of post pubertal growth.

A high-flow nasal cannula versus noninvasive ventilation in acute exacerbations of chronic obstructive pulmonary disease.

PURPOSE: We investigated the efficacy and safety of a high-flow nasal cannula (HFNC) at different flow rates compared to noninvasive ventilation (NIV) in patients with acute chronic obstructive pulmonary disease (COPD) exacerbations. METHODS: This prospective, randomized, single-blind study assigned patients to one of three study groups. The NIV group (n = 47) received bilevel positive airway pressure. The HFNC-30 (n = 44) and HFNC-50 (n = 46) groups received HFNC therapy at flow rates of 30 and 50 L/min, respectively. Demographic and clinical characteristics and arterial blood gas parameters before and 30, 60, and 120 min after treatment were compared among the treatment groups. RESULTS: This study included 137 consecutive patients with acute exacerbations of COPD, comprising 90 males and 47 females, with a mean age of 68.1 ± 10.5 years. A total of 21 patients (15.33 %) were intubated, and the overall mortality rate was 10.2 %. The mean PaCO2 levels on admission were 64.69 ± 10.81, 61.51 ± 9.03, and 62.29 ± 9.87 in the NIV, HFNC-30, and HFNC-50 groups, respectively, with no significant differences observed (p = 0.372). A significant reduction in mean PaCO2 was observed in all treatment groups at 30, 60, and 120 min (p < 0.05 for all). However, the ΔPaCO2 at 60 min was significantly higher in the HFNC-30 group compared to the NIV group (p = 0.042). Additionally, neither intubation rates nor 28-day mortality differed among the treatment groups (p = 0.368 and p = 0.775, respectively). CONCLUSION: HFNC was not inferior to NIV in improving arterial blood gas parameters, particularly PaCO2 in patients with COPD exacerbations, especially those with hypercarbia. Moreover, HFNC at a flow rate of 30 L/min was superior to NIV for reducing PaCO2 levels at 60 min. TRIAL REGISTRY: National Library of Medicine Clinical Trial Registry; No.: NCT06495086; URL: https://clinicaltrials.gov/study/NCT06495086.

Emergency medicine updates: Endotracheal intubation.

INTRODUCTION: Airway management including endotracheal intubation (ETI) is a key skill for emergency clinicians. Therefore, it is important for emergency clinicians to be aware of the current evidence regarding the identification and management of patients requiring ETI. OBJECTIVE: This paper evaluates key evidence-based updates concerning ETI for the emergency clinician. DISCUSSION: ETI is commonly performed in the emergency department (ED) setting but has many nuanced components. There are several tools that have been used to predict a difficult airway which incorporate anatomic and physiologic features. While helpful, these tools should not be used in isolation. Preoxygenation and apneic oxygenation are recommended to reduce the risk of desaturation and patient decompensation, particularly with noninvasive ventilation in critically ill patients. Induction and neuromuscular blocking medications should be tailored to the clinical scenario. Video laryngoscopy is superior to direct laryngoscopy among novice users, while both techniques are reasonable among more experienced clinicians. Recent literature suggests using a bougie during the first attempt. Point-of-care ultrasound is helpful for confirming correct placement and depth of the endotracheal tube. CONCLUSIONS: An understanding of literature updates can improve the ED care of patients requiring emergent intubation.

Incidence of noninvasive ventilation failure and mortality in patients with acute respiratory distress syndrome: a systematic review and proportion meta-analysis.

BACKGROUND: Noninvasive ventilation (NIV) is commonly used in patients with acute respiratory distress syndrome (ARDS). However, the incidence and distribution of treatment failure are unclear. METHODS: A comprehensive online search was conducted to select potentially eligible studies with reports of the rate of NIV failure in patients with ARDS. A manual search was also performed to identify additional studies. Data were extracted to calculate the pooled incidences of NIV failure and mortality. Based on oxygenation, the severity of the disease was classified as mild, moderate, or severe ARDS. Based on etiologies, ARDS was defined as being of pulmonary origin or extrapulmonary origin. RESULTS: We enrolled 90 studies in this meta-analysis, involving 98 study arms. The pooled incidence of NIV failure was 48% (n = 5847, 95% confidence interval [CI]: 43-52%). The pooled incidence of ICU mortality was 29% (n = 2363, 95%CI: 22-36%), and that of hospital mortality was 33% (n = 2927, 95%CI: 27-40%). In patients with mild, moderate, and severe ARDS, the pooled incidence of NIV failure was 30% (n = 819, 95%CI: 21-39%), 51% (n = 1332, 95%CI: 43-60%), and 71% (n = 525, 95%CI: 62-79%), respectively. In patients with pulmonary ARDS, it was 45% (n = 2687, 95%CI: 39-51%). However, it was 30% (n = 802, 95%CI: 21-38%) in those with extrapulmonary ARDS. In patients with immunosuppression, the incidence of NIV failure was 62% (n = 806, 95%CI: 50-74%). However, it was 46% (n = 5041, 95%CI: 41-50%) in those without immunosuppression. CONCLUSIONS: Nearly half of patients with ARDS experience NIV failure. The incidence of NIV failure increases with increasing ARDS severity. Pulmonary ARDS seems to have a higher rate of NIV failure than extrapulmonary ARDS. ARDS patients with immunosuppression have the highest rate of NIV failure.

Effects of high-flow nasal cannula oxygen therapy in bronchiectasis and hypercapnia: a retrospective observational study.

BACKGROUND: The effectiveness of high-flow nasal cannula (HFNC) therapy in patients with bronchiectasis experiencing hypercapnia remains unclear. Our aim was to retrospectively analyze the short-term outcomes of HFNC therapy in such patients, and to further explore the predictors of HFNC treatment failure in this particular patient population. METHODS: A retrospective review was conducted on patients with bronchiectasis who received HFNC (n = 70) for hypercapnia (arterial partial pressure of carbon dioxide, PaCO2 ≥ 45 mmHg) between September 2019 and September 2023. RESULTS: In the study population, 30% of patients presented with acidemia (arterial pH < 7.35) at baseline. Within 24 h of HFNC treatment, there was a significant reduction in PaCO2 levels by a mean of 4.0 ± 12.7 mmHg (95% CI -7.0 to -1.0 mmHg). Concurrently, arterial pH showed a statistically significant increase with a mean change of 0.03 ± 0.06 (95% CI 0.01 to 0.04). The overall hospital mortality rate in our study was 17.5%. The median length of hospital stay was 11.0 days (interquartile range [IQR] 8.0 to 16.0 days). Sub-analysis revealed no statistically significant differences in hospital mortality (19.0% vs. 20.4%, p = 0.896), length of hospital stay (median 14.0 days [IQR 9.0 to 18.0 days] vs. 10.0 days [IQR 7.0 to 16.0 days], p = 0.117) and duration of HFNC application (median 5.0 days [IQR 2.0 to 8.5 days] vs. 6.0 days [IQR 4.9 to 9.5 days], p = 0.076) between the acidemia group and the non-acidemia group (arterial pH ≥ 7.35). However, more patients in the non-acidemia group had do-not-intubate orders. The overall treatment failure rate for HFNC was 28.6%. Logistic regression analysis identified the APACHE II score (OR 1.24 per point) as the independent predictor of HFNC failure. CONCLUSIONS: In patients with bronchiectasis and hypercapnia, HFNC as an initial respiratory support can effectively reduce PaCO2 level within 24 h of treatment. A high APACHE II score has emerged as a prognostic indicator for HFNC treatment failure. These observations highlight randomized controlled trials to meticulously evaluate the efficacy of HFNC in this specific population.

PaCO2 is nonlinearly associated with NIV failure in patients with hypoxemic respiratory failure.

OBJECTIVE: To explore the association between PaCO2 and noninvasive ventilation (NIV) failure in patients with hypoxemic respiratory failure. METHODS: A retrospective study was performed in a respiratory ICU of a teaching hospital. Patients admitted to ICU between 2011 and 2019 were screened. We enrolled the patients with hypoxemic respiratory failure. However, patients who used NIV due to acute-on-chronic respiratory failure or heart failure were excluded. Data before the use of NIV were collected. Requirement of intubation was defined as NIV failure. RESULTS: A total of 1029 patients were enrolled in final analysis. The rate of NIV failure was 45% (461/1029). A nonlinear relationship between PaCO2 and NIV failure was found by restricted cubic splines (p = 0.03). The inflection point was 32 mmHg. The rate of NIV failure was 42% (224/535) in patients with PaCO2 >32 mmHg. However, it increased to 48% (237/494) in those with PaCO2 ≤ 32 mmHg. The crude and adjusted hazard ratio (HR) for NIV failure was 1.36 (95%CI:1.13-1.64) and 1.23(1.01-1.49), respectively, if the patients with PaCO2 >32 mmHg were set as reference. In patients with PaCO2 ≤ 32 mmHg, one unit increment of PaCO2 was associated with 5% reduction of NIV failure. However, it did not associate with NIV failure in patients with PaCO2 >32 mmHg. CONCLUSIONS: PaCO2 and NIV failure was nonlinear relationship. The inflection point was 32 mmHg. Below the inflection point, lower PaCO2 was associated with higher NIV failure. However, it did not associate with NIV failure above this point.

High-flow nasal cannula oxygen therapy versus noninvasive ventilation for elderly chronic obstructive pulmonary disease patients after extubation: a noninferior randomized controlled trial protocol.

INTRODUCTION: Noninvasive ventilation (NIV) is widely used for sequential extubation in patients with chronic obstructive pulmonary disease (COPD). However, NIV may cause many adverse events such as claustrophobia, facial skin compression, air leakage, bloating, and even reflux aspiration, resulting in poor patient compliance/tolerance and high failure rate, especially for older adults who are at high risk of communication difficulties and consciousness disorder. High-flow nasal cannula (HFNC) oxygen therapy is a new alternative support to NIV, but whether it can effectively reduce the rate of re-intubation after extubation in elderly patients with COPD remains controversial. The purpose of this study is to explore the safety and efficacy of HFNC versus NIV for elderly COPD patients after extubation. METHODS AND ANALYSIS: This study is an investigator-initiated, single-center, prospective, non-inferior, randomized controlled trial. Elderly patients (age > 65 years) who have received invasive ventilation and was diagnosed with COPD will be randomly assigned to HFNC group or NIV group immediately after extubation with a planned enrollment of 168 patients. The primary outcomes will be reintubation rates at 72 h and 7 days after extubation. Secondary outcomes will include treatment failure, post-extubation vital signs and arterial blood gases, the scores of compliance and comfort of patients, duration of respiratory support after extubation, respiratory support related adverse events, sleep quality scores, usage of sedative and analgesic drugs after extubation, and the incidence of delirium. Additionally, clinical outcomes such as ventilator-free days at 28 days post-randomization, tracheotomy rate, duration of intensive care unit (ICU) and hospital stay, ICU and hospital mortality will be evaluated. ETHICS AND DISSEMINATION: This study has been approved by the Ethics Committee of West China Hospital of Sichuan University (2023-2284). Informed consent is required. It is expected that a follow-up randomized controlled trial will be conducted. The results will be submitted for publication in a peer-reviewed journal and presented at one or more scientific conferences. TRIAL REGISTRATION: The study was retrospectively registered at ClinicalTrials.gov (ChiCTR2400087312).

"Comparison between high-flow nasal cannula (HFNC) therapy and noninvasive ventilation (NIV) in children with acute respiratory failure by bronchiolitis: a randomized controlled trial".

BACKGROUND: The objective of this study was to compare HFNC therapy to noninvasive ventilation (NIV/BiPAP) in children with bronchiolitis who developed respiratory failure. We hypothesized that HFNC therapy would not be inferior to NIV. METHODS: This was a noninferiority open-label randomized single-center clinical trial conducted at a tertiary Brazilian hospital. Children under 2 years of age with no chronic conditions admitted for bronchiolitis that progressed to mild to moderate respiratory distress (Wood-Downes-Férres score < 8) were randomized to either the HFNC group or NIV (BiPAP) group through sealed envelopes. Vital signs, FiO2, Wood-Downes-Férres score and HFNC/NIV parameters were recorded up to 96 h after therapy initiation. Children who developed respiratory failure despite receiving initial therapy were intubated. Crossover was not allowed. The primary outcome analyzed was invasive mechanical ventilation requirement. The secondary outcomes were sedation usage, invasive mechanical ventilation duration, the PICU LOS, the hospital LOS, and mortality rate. RESULTS: A total of 126 patients were allocated to the NIV group (132 randomized and 6 excluded), and 126 were allocated to the HFNC group (136 randomized and 10 excluded). The median age was 2.5 (1-6) months in the NIV group and 3 (2-7) months in the HFNC group (p = 0,07). RSV was the most common virus isolated in both groups (72% vs. 71.4%, NIV and HFNC, respectively). Thirty-seven patients were intubated in the NIV group and 29 were intubated in the HFNC group (29% vs. 23%, p = 0.25). According to the Farrington-Manning test, with a noninferiority margin of 15%, the difference was 6.3% in favor of HFNC therapy (95% confidence interval: -4.5 to 17.1%, p < 0.0001). There was no significant difference in the PICU LOS or sedation duration. Sedation requirement, hospital LOS and invasive mechanical ventilation duration were lower in the HFNC group. CONCLUSION: HFNC therapy is noninferior to NIV in infants admitted with mild to moderate respiratory distress caused by bronchiolitis that progresses to respiratory failure. TRIAL REGISTRATION NUMBERS: U1111-1262-1740; RBR-104z966s. Registered 03/01/2023 (retrospectively registered). ReBEC: https://ensaiosclinicos.gov.br/rg/RBR-104z966s .

Noninvasive respiratory support preventing reintubation after pediatric cardiac surgery-A systematic review.

OBJECTIVE: To analyze the optimal postextubation respiratory support in pediatric cardiac surgery patients. DESIGN: Systematic review of randomized controlled trials. SETTING: Pediatric or neonatal intensive care units. PARTICIPANTS: All aged children (<16 years) having cardiac surgery and postoperative invasive ventilation. INTERVENTION: Noninvasive respiratory support, including high flow nasal cannula (HFNC), conventional oxygen therapy (COT), noninvasive positive pressure ventilation (NIPPV), continuous positive pressure (CPAP), and noninvasive high-frequency oscillatory ventilation (NHFOV). MEASUREMENT AND MAIN RESULTS: Studies were not pooled for statistical synthesis due to the limited number and quality of the included studies. Risk ratios with 95% confidence intervals were calculated for individual studies. A total of 167 studies were screened and six were included. The risk of bias was low in one, high in one, and had some concerns in four of the studies. Extubation failure (defined as reintubation) was the main outcome of interest. Risk ratio for reintubation was 0.10 (CI 0.02-0.40) and 1.07 (CI 0.16-7.26) in HFNC versus COT, 0.49 (CI 0.05-5.28) in HFNC versus NIPPV, 0.40 (CI 0.08-1.94) in HFNOV versus CPAP, 0.75 (CI 0.26-2.18) in HFNOV versus NIPPV, and 1.37 (CI 0.33-5.73) in CPAP versus NIPPV. Treatment durations did not differ between the groups. CONCLUSION: We did not find clear evidence of a difference in reintubation rates and other clinical outcomes between different noninvasive ventilation strategies. Evidence certainty was assessed to be very low due to the risk of bias, the small number of included studies, and high imprecision. Future quality studies are needed to determine the optimal postextubation support in pediatric cardiac surgery patients.

Use of high-flow nasal cannula versus other noninvasive ventilation techniques or conventional oxygen therapy for respiratory support following pediatric cardiac surgery: A systematic review and meta-analysis.

INTRODUCTION: Noninvasive respiratory support may be provided to decrease the risk of postextubation failure following surgery. Despite these efforts, approximately 3%-27% of infants and children still experience respiratory failure after tracheal extubation following cardiac surgery. This systematic review evaluates studies comparing the efficacy of high-flow nasal cannula to conventional oxygen therapy such as nasal cannula and other noninvasive ventilation techniques in preventing postextubation failure in this patient population. METHODS: A systematic and comprehensive search was conducted in major databases including MEDLINE, EMBASE, Web of Science, and Central. The search encompassed articles focusing on the prophylactic use of high-flow nasal cannula following tracheal extubation in pediatric patients undergoing cardiac surgery for congenital heart disease. The inclusion criteria for this review consisted of randomized clinical trials as well as observational, cohort, and case-control studies. RESULTS: A total of 1295 studies were screened and 12 studies met the inclusion criteria. These 12 studies included a total of 1565 children, classified into three groups: seven studies compared high-flow nasal cannula to noninvasive ventilation techniques, four studies compared high-flow nasal cannula to conventional oxygen therapy, and one observational single-arm study explored the use of high-flow nasal cannula with no control group. There was no significant difference in the incidence of tracheal reintubation between high-flow nasal cannula and conventional oxygen therapy (risk ratio [RR] = 0.67, 95% confidence interval [CI]: 0.24-1.90, p = .46). However, there was a lower incidence of tracheal reintubation in patients who were extubated to high-flow nasal cannula versus those extubated to noninvasive ventilation techniques (RR = 0.45, 95% CI: 0.32-0.63, p < .01). The high-flow nasal cannula group also demonstrated a lower mortality rate compared to the noninvasive ventilation techniques group (RR = 0.31, 95% CI: 0.16-0.61, p < .01) as well as a shorter postoperative length of stay (mean difference = -8.76 days, 95% CI: -13.08 to -4.45, p < .01) and shorter intensive care length of stay (mean difference = -4.63 days, 95% CI: -9.16 to -0.11, p = .04). CONCLUSION: High-flow nasal cannula is more effective in reducing the rate of postextubation failure compared to other forms of noninvasive ventilation techniques following surgery for congenital heart disease in pediatric-aged patients. high-flow nasal cannula is also associated with lower mortality rates and shorter length of stay. However, when comparing high-flow nasal cannula to conventional oxygen therapy, the findings were inconclusive primarily due to a limited number of scientific studies available on this specific comparison. Future study is needed to further define the benefit of high-flow nasal cannula compared to conventional oxygen therapy and various types of noninvasive ventilation techniques.