Longitudinal Assessment of ROX and HACOR Scores to Predict Non-Invasive Ventilation Failure in Patients with SARS-CoV-2 Pneumonia.

Introduction: NIV (Non-invasive ventilation) and HFNC (High Flow nasal cannula) are being used in patients with acute respiratory failure. HACOR score has been exclusively calculated for patients on NIV, on other hand ROX index is being used for patients on HFNC. This is first study where ROX index has been used in patients on NIV to predict failure. Aim of the study: This study investigates the comparative diagnostic performance of HACOR score and ROX index to predict NIV failure. Methods: We performed a retrospective cohort study of non-invasively ventilated COVID-19 patients admitted between 1st April 2020 to 15th June 2021 to ICU of a tertiary care teaching hospital located in Central India. We assessed factors responsible for NIV failure, and whether these scores HACOR/ROX index have discriminative capacity to predict risk of invasive mechanical ventilation. Results: Of the 441 patients included in the current study, 179 (40.5%) recovered, while remaining 262 (59.4%) had NIV failure. On multivariable analysis, ROX index > 4.47 was found protective for NIV-failure (OR 0.15 (95% CI 0.03-0.23; p<0.001). Age > 60 years and SOFA score were other significant independent predictors of NIV-failure. The AUC for prediction of failure rises from 0.84 to 0.94 from day 1 to day 3 for ROX index and from 0.79 to 0.92 for HACOR score in the same period, hence ROX score was non-inferior to HACOR score in current study. DeLong's test for two correlated ROC curves had insignificant difference expect day-1 (D1: 0.03 to 0.08; p=3.191e-05, D2: -0.002 to 0.02; p = 0.2671, D3: -0.003 to 0.04; p= 0.1065). Conclusion: ROX score of 4.47 at day-3 consists of good discriminatory capacity to predict NIV failure. Considering its non-inferiority to HACOR score, the ROX score can be used in patients with acute respiratory failure who are on NIV.

Nasal microRNA signatures for disease severity in infants with respiratory syncytial virus bronchiolitis: a multicentre prospective study.

BACKGROUND: Respiratory syncytial virus (RSV) bronchiolitis contributes to a large morbidity and mortality burden globally. While emerging evidence suggests that airway microRNA (miRNA) is involved in the pathobiology of RSV infection, its role in the disease severity remains unclear. METHODS: In this multicentre prospective study of infants (aged<1 year) hospitalised for RSV bronchiolitis, we sequenced the upper airway miRNA and messenger RNA (mRNA) at hospitalisation. First, we identified differentially expressed miRNAs (DEmiRNAs) associated with higher bronchiolitis severity-defined by respiratory support (eg, positive pressure ventilation, high-flow oxygen therapy) use. We also examined the biological significance of miRNAs through pathway analysis. Second, we identified differentially expressed mRNAs (DEmRNAs) associated with bronchiolitis severity. Last, we constructed miRNA-mRNA coexpression networks and determined hub mRNAs by weighted gene coexpression network analysis (WGCNA). RESULTS: In 493 infants hospitalised with RSV bronchiolitis, 19 DEmiRNAs were associated with bronchiolitis severity (eg, miR-27a-3p, miR-26b-5p; false discovery rate<0.10). The pathway analysis using miRNA data identified 1291 bronchiolitis severity-related pathways-for example, regulation of cell adhesion mediated by integrin. Second, 1298 DEmRNAs were associated with bronchiolitis severity. Last, of these, 190 DEmRNAs were identified as targets of DEmiRNAs and negatively correlated with DEmiRNAs. By applying WGCNA to DEmRNAs, four disease modules were significantly associated with bronchiolitis severity-for example, microtubule anchoring, cell-substrate junction. The hub genes for each of these modules were also identified-for example, PCM1 for the microtubule anchoring module, LIMS1 for the cell-substrate junction module. CONCLUSIONS: In infants hospitalised for RSV bronchiolitis, airway miRNA-mRNA coexpression network contributes to the pathobiology of bronchiolitis severity.

Initiation of Chronic Non-invasive Ventilation.

Initiation of home non-invasive ventilation (NIV) requires careful consideration of the patient's condition, motivation, expectations, wishes, and social circumstances. The decision to start NIV depends on a combination of factors including patient symptoms and objective evidence of nocturnal hypoventilation. A solid understanding of the underlying pathophysiology is key to a systematic and well-balanced clinical approach to titrating NIV. The location where NIV is initiated is not the most relevant issue, provided that it is a comfortable, safe environment in which adequate monitoring can be assured. The majority of patients prefer their own home for treatment initiation.

Telemonitoring in Non-invasive Ventilation.

Telemonitoring in non-invasive ventilation is constantly evolving to enable follow-up of adults and children. Depending on the device and manufacturer, different ventilator variables are displayed on web-based platforms. However, high-granularity measurement is not always available remotely, which precludes breath-by-breath waveforms and precise monitoring of nocturnal gas exchange. Therefore, telemonitoring is mainly useful for monitoring utilization of the device, leaks, and respiratory events. Coordinated relationships between patients, homecare providers, and hospital teams are necessary to transform available data into diagnosis and actions. Telemonitoring is time and cost-consuming. The balance between cost, workload, and clinical benefit should be further evaluated.

The Role of High Flow Nasal Therapy in Chronic Respiratory Failure.

High-flow nasal therapy (HFNT) has an increasing role in the management of acute hypoxic respiratory failure. Due to its tolerable interface and ease of use, its role in chronic hypercapnic respiratory failure (CHRF) is emerging. This article examines the literature to date surrounding the short and long-term mechanisms of HFNT in sleep and wakefulness of CHRF patients. It is likely HFNT will have an increasing role in those patients intolerant of non-invasive ventilation.

Ventilation strategies in cardiogenic shock: Insights from the AltShock-2 registry.

AIMS: To describe the use and the relation to outcome of different ventilation strategies in a contemporary, large, prospective registry of cardiogenic shock patients. METHODS AND RESULTS: Among 657 patients enrolled from March 2020 to November 2023, 198 (30.1%) received oxygen therapy (OT), 96 (14.6%) underwent non-invasive ventilation (NIV), and 363 (55.3%) underwent invasive mechanical ventilation (iMV). Patients in the iMV group were significantly younger compared to those in the NIV and OT groups (63 vs. 69 years, p < 0.001). There were no significant differences between groups regarding cardiovascular risk factors. Patients with SCAI B and C were more frequently treated with OT and NIV compared to iMV (65.1% and 65.4% vs. 42.6%, respectively, p > 0.001), while the opposite trend was observed in SCAI D patients (12% and 12.2% vs. 30.9%, respectively, p < 0.001). All-cause mortality at 24 h did not differ amongst the three groups. The 60-day mortality rates were 40.2% for the iMV group, 26% for the OT group, and 29.3% for the NIV group (p = 0.005), even after excluding patients with cardiac arrest at presentation. In the multivariate analysis including SCAI stages, NIV was not associated with worse mortality compared to iMV (hazard ratio 1.97, 95% confidence interval 0.85-4.56), even in more severe SCAI stages such as D. CONCLUSIONS: Compared to previous studies, we observed a rising trend in the utilization of NIV among cardiogenic shock patients, irrespective of aetiology and SCAI stages. In this clinical scenario, NIV emerges as a safe option for appropriately selected patients.

Creatine Kinase and Respiratory Decline in Amyotrophic Lateral Sclerosis.

Respiratory dysfunction is an important hallmark of amyotrophic lateral sclerosis (ALS). Elevation of creatine kinase (CK) has been reported in 23-75% of ALS patients, but the underlying mechanisms remain unknown. This work aims to enlighten the role of CK as a prognostic factor of respiratory dysfunction in ALS. A retrospective analysis of demographic and clinical variables, CK, functional decline per month (ΔFS), forced vital capacity (%FVC), and mean amplitude of the phrenic nerve compound motor action potential (pCMAP) in 319 ALS patients was conducted. These measurements were evaluated at study entry, and patients were followed from the moment of first observation until death or last follow-up visit. High CK values were defined as above the 90th percentile (CK ≥ P90) adjusted to sex. We analyzed survival and time to non-invasive ventilation (NIV) as proxies for respiratory impairment. Linear regression analysis revealed that high CK was associated with male sex (p < 0.001), spinal onset (p = 0.018), and FVC ≥ 80% (p = 0.038). CK was 23.4% higher in spinal-onset ALS patients (p < 0.001). High CK levels were not linked with an increased risk of death (p = 0.334) in Cox multivariate regression analysis. CK ≥ P90 (HR = 1.001, p = 0.038), shorter disease duration (HR = 0.937, p < 0.001), lower pCMAP (HR = 0.082, p < 0.001), and higher ΔFS (HR = 1.968, p < 0.001) were risk factors for respiratory failure. The association between high CK levels and poorer respiratory outcomes could derive from cellular metabolic stress or a specific phenotype associated with faster respiratory decline. Our study suggests that CK measurement at diagnosis should be more extensively investigated as a possible marker of poor respiratory outcome in future studies, including a larger population of patients.

Breathlessness assessment, management and impact in the intensive care unit: a rapid review and narrative synthesis.

BACKGROUND: Adults in the intensive care unit (ICU) commonly experience distressing symptoms and other concerns such as pain, delirium, and breathlessness. Breathlessness management is not supported by any ICU guidelines, unlike other symptoms. AIM: To review the literature relating to (i) prevalence, intensity, assessment, and management of breathlessness in critically ill adults in the ICU receiving invasive and non-invasive mechanical ventilation (NIV) and high-flow oxygen therapy, (HFOT), (ii) the impact of breathlessness on ICU patients with regard to engagement with rehabilitation. METHODS: A rapid review and narrative synthesis using the Cochrane Methods Group Recommendations was conducted and reported in accordance with PRISMA. All study designs investigating breathlessness in adult ICU patients receiving either invasive mechanical ventilation (IMV), NIV or HFOT were eligible. PubMed, MEDLINE, The Cochrane Library and CINAHL databased were searched from June 2013 to June 2023. Studies were quality appraised. RESULTS: 19 studies representing 2822 ICU patients were included (participants mean age 48 years to 71 years; proportion of males 43-100%). The weighted mean prevalence of breathlessness in ICU patients receiving IMV was 49% (range 34-66%). The proportion of patients receiving NIV self-reporting moderate to severe dyspnoea was 55% prior to initiation. Breathlessness assessment tools included visual analogue scale, (VAS), numerical rating scale, (NRS) and modified BORG scale, (mBORG). In patients receiving NIV the highest reported median (interquartile range [IQR]) VAS, NRS and mBORG scores were 6.2cm (0-10 cm), 5 (2-7) and 6 (2.3-7) respectively (moderate to severe breathlessness). In patients receiving either NIV or HFOT the highest reported median (IQR) VAS, NRS and mBORG scores were 3 cm (0-6 cm), 8 (5-10) and 4 (3-5) respectively. CONCLUSION: Breathlessness in adults receiving IMV, NIV or HFOT in the ICU is prevalent and clinically important with median intensity ratings indicating the presence of moderate to severe symptoms.

High-flow nasal cannula oxygen therapy for mild-moderate acute respiratory failure in patients with blunt chest trauma: An exploratory descriptive study.

OBJECTIVE: The use of high-flow nasal cannula (HFNC) oxygen therapy is gaining popularity for the treatment of acute respiratory failure (ARF). However, limited evidence exists regarding the effectiveness of HFNC for hypoxemic ARF in patients with blunt chest trauma (BCT). METHODS: This retrospective analysis focused on BCT patients with mild-moderate hypoxemic ARF who were treated with either HFNC or non-invasive ventilation (NIV) in the emergency medicine department from January 2021 to December 2022. The primary endpoint was treatment failure, defined as either invasive ventilation, or a switch to the other study treatment (NIV for patients in the NFNC group, and vice-versa). RESULTS: A total of 157 patients with BCT (72 in the HFNC group and 85 in the NIV group) were included in this study. The treatment failure rate in the HFNC group was 11.1% and 16.5% in the NIV group - risk difference of 5.36% (95% CI, -5.94-16.10%; P = 0.366). The most common cause of failure in the HFNC group was aggravation of respiratory distress. While in the NIV group, the most common reason for failure was treatment intolerance. Treatment intolerance in the HFNC group was significantly lower than that in the NIV group (1.4% vs 9.4%, 95% CI 0.40-16.18; P = 0.039). Univariate logistic regression analysis showed that chronic respiratory disease, abbreviated injury scale score (chest) (≥3), Acute Physiology and Chronic Health Evaluation II score (≥15), partial arterial oxygen tension /fraction of inspired oxygen (≤200) at 1 h of treatment and respiratory rate (≥32 /min) at 1 h of treatment were risk factors associated with HFNC failure. CONCLUSION: In BCT patients with mild-moderate hypoxemic ARF, the usage of HFNC did not lead to higher rate of treatment failure when compared to NIV. HFNC was found to offer better comfort and tolerance than NIV, suggesting it may be a promising new respiratory support therapy for BCT patients with mild-moderate ARF.

Indications and techniques of non-invasive ventilation (NIV) in neuromuscular diseases.

The neuromuscular patients may experience the need for respiratory support due to the onset of respiratory failure. Some skills are essential to achieve therapeutic success. In addition to technical knowledge, it is essential to have knowledge relating to individual neuromuscular diseases. The availability of alternative respiratory supports and various interfaces can be a valuable weapon at different moments in the course of the neuromuscular disease. Furthermore, the doctor-patient relationship plays a key role as does taking care of the patient's psychological sphere.

Nutrition therapy in non-intubated patients with acute respiratory failure: a narrative review.

Objectives: Non-invasive ventilation use is increasing in patients from acute respiratory failure. However, nutritional assessment and medical nutritional therapy are often missed and patients may be frequently underfed. This review evaluates the tools for nutritional screening and assessment, assesses the use of medical nutritional therapy in various techniques of non invasive ventilation and suggested tools to improve this therapy. Methods, results: A review of the literature was performed to evaluate the tools available to define malnutrition and determine the energy needs of patients requiring non invasive ventilation. Energy and protein intake was assessed in 16 recent papers. High Flow Nasal Cannula Oxygen therapy and non invasive ventilation using mask were described and nutritional therapy determined in each condition.The Global Leadership International Malnutrition Assessment seems to be the best assessment to be recommended. Energy expenditure is optimally obtained by indirect calorimetry. Patients with Non invasive ventilation are even more underfed than patients receiving High Flow Nasal Cannula Oxygen therapy. Conclusions: A better determination of malnutrition, a more adequate energy requirement and an improved energy and protein administration are required in patients with acute respiratory failure treated with non invasive ventilation.

Practical recommendations for swallowing and speaking during NIV in people with neuromuscular disorders.

Objectives: The functions of eating, drinking, speaking, and breathing demand close coordination of the upper airway musculature which may be challenged by the long-term use of daytime non-invasive ventilation (NIV). This rapid review explores the challenges and practicalities of these interactions in people with neuromuscular disorders. Methods: A search was performed on PubMed (period 2000-2023) using generic terms to refer to eating, drinking, and speaking related to people with neuromuscular disorders on NIV. A narrative approach was used to summarize the available literature. Results: Our review shows only a small number of studies exist exploring the use of NIV on swallowing and speaking in people with neuromuscular disorders. We summarize study findings and provide practical advice on eating, drinking and speaking with NIV. Conclusions: By understanding breathing, NIV mechanics and upper airway interactions, it is possible to optimize swallowing and speaking whilst using NIV. There is a lack of specific guidelines, and concerns regarding aspiration warrant further research and guideline development.

Enhancing respiratory function in neuromuscular disease: the role of non-invasive ventilation. A narrative review.

Neuromuscular diseases (NMDs) comprise a heterogeneous group of conditions characterized by extreme progressive muscle weakness leading to respiratory failure. Noninvasive mechanical ventilation (NIV) has emerged as a cornerstone in the management of respiratory complications associated with NMDs. This review aims to elucidate the role of NMV in respiratory function, improving quality of life, and prolonging survival in individuals with NMD. The physiological basis of respiratory impairment in NMDs, principles of NMV application, evidence supporting its efficacy, patient selection criteria, and potential challenges in its application are discussed.

Establishment and Validation of a Risk Prediction Model for Non-Invasive Ventilation Failure After Birth in Premature Infants with Gestational Age < 32 Weeks.

OBJECTIVES: This study was performed to construct and validate a risk prediction model for non-invasive ventilation (NIV) failure after birth in premature infants with gestational age < 32 weeks. METHODS: The data were derived from the multicenter retrospective study program - Jiangsu Provincial Neonatal Respiratory Failure Collaboration Network from Jan 2019 to Dec 2021. The subjects finally included were preterm infants using NIV after birth with gestational age less than 32 weeks and admission age within 72 h. After screening by inclusion and exclusion criteria, 1436 babies were subsequently recruited in the study, including 1235 infants in the successful NIV group and 201 infants in the failed NIV group. RESULTS: (1) Gestational age, 5 min Apgar, Max FiO2 during NIV, and FiO2 fluctuation value during NIV were selected by univariate and multivariate analysis. (2) The area under the curve of the prediction model was 0.807 (95% CI: 0.767-0.847) in the training set and 0.825 (95% CI: 0.766-0.883) in the test set. The calibration curve showed good agreement between the predicted probability and the actual observed probability (Mean absolute error = 0.008 for the training set; Mean absolute error = 0.012 for the test set). Decision curve analysis showed good clinical validity of the risk model in the training and test cohorts. CONCLUSION: This model performed well on dimensions of discrimination, calibration, and clinical validity. This model can serve as a useful tool for neonatologists to predict whether premature infants will experience NIV failure after birth.

The use of venous blood gas in assessing arterial acid-base and oxygenation status - an analysis of aggregated data from multiple studies evaluating the venous to arterial conversion (v-TAC) method.

BACKGROUND: Several methods exist to reduce the number of arterial blood gases (ABGs). One method, Roche v-TAC, has been evaluated in different patient groups. This paper aggregates data from these studies, in different patient categories using common analysis criteria. RESEARCH DESIGN AND METHODS: We included studies evaluating v-TAC based on paired arterial and peripheral venous blood samples. Bland-Altman analysis compared measured and calculated arterial values of pH, PCO2, and PO2. Subgroup analyses were performed for normal, chronic hypercapnia and chronic base excess, acute hyper- and hypocapnia, and acute and chronic base deficits. RESULTS: 811 samples from 12 studies were included. Bias and limits of agreement for measured and calculated values: pH 0.001 (-0.029 to 0.031), PCO2 -0.08 (-0.65 to 0.49) kPa, and PO2 0.04 (-1.71 to 1.78) kPa, with similar values for all sub-group analyses. CONCLUSION: These data suggest that v-TAC analysis may have a role in replacing ABGs, avoiding arterial puncture. Substantial data exist in patients with chronic hypercapnia and chronic base excess, acute hyper- and hypocapnia, and in patients with relatively normal acid-base status, with similar bias and precision across groups and across study data. Limited data exist for patients with acute and chronic base deficits.

Home non-invasive ventilation: An observational study of aetiology, chronic respiratory failure of multiple aetiologies, survival and treatment adherence.

Home non-invasive ventilation (NIV) is used to treat patients with chronic respiratory failure (CRF). However, knowledge on the prevalence and impact of multimorbid aetiology of CRF, patterns of NIV use, and survival of these patients is limited. Our aim was to analyse the multiple aetiologies of CRF, patterns of NIV use and the outcome of those patients. We conducted a retrospective analysis of 1,281 patients treated with home-NIV between 2004 and 2014 in Turku University Hospital, Finland. The patients were divided into nine disease categories: obstructive airways disease (16 %); obesity hypoventilation syndrome (11 %); neuromuscular disease (10 %); chest wall diseases (4 %); sleep apnoea (26 %); interstitial lung diseases (3 %); malignancy (2 %); other (3 %) and acute (8 %), which refers to the patients who did not fulfil criteria of CRF. In addition, multiple aetiologies of CRF were found in 17 %. Mean adherence to home-NIV was 6.0 ± 4.4 h/d and median treatment duration 410 (120-1021) days. Adherence, treatment duration or survival did not significantly differ between patients with either single or multiple causative diseases leading to CRF. Median survival was 4.5 years (95 % CI 3.6 to 5.4). The main reasons for discontinuing NIV were death (56 %) and lack of motivation (19 %). We conclude that home-NIV is used in a variety of diseases. CRF of multiple aetiologies is prevalent and not limited to chronic obstructive lung disease and obstructive sleep apnoea overlap syndrome. However, the adherence to home-NIV or survival did not differ between patients with a single or multiple diseases causing CRF, but the survival of the home-NIV patients differed according to the underlying aetiology of CRF.

Characteristics of Patients With Amyotrophic Lateral Sclerosis Followed by a Home Palliative Care Team.

BACKGROUND: Information about patients with amyothrophic lateral sclerosis (ALS) followed at home is limited. OBJECTIVES: To assess patients's characteristics at admission to a home palliative care program based on a multidisciplinary team, and the temporal course along the trajectory of ALS disease. DESIGN: Retrospective. Setting/subjects: Charts of a consecutive number of ALS patients who were referred to a specialistic home palliative care were reviewed. MEASUREMENT: General data, referral, start of home palliative care, use of ventilator support and nutritional support, were recorded. The existence of advance directives and shared care planning was also collected. RESULTS: 82 patients were examined; 31 patients died before the term of the study and 51 patients were still living. No patient anticipately expressed their will regarding their treatments. However, a certain number of patients shared a care planning with ALS team, generally after starting home care. Most patients did not have ventilatory support at the beginning of home care assistance, but progressively received ventilatory support by NIV or MV, particularly those who were still living. NIV at start of home care was negatively correlated to frontotemporal dementia. (P = 0.015), and directly correlated to referral from hospital and GP (P = 0.031) and awareness of disease (P = 0.034). Gastrostomy at start of home care was positively correlated to referral from hospital (P = 0.046). Gastrostomy during home care was correlated to bulbar SLA (P = 0.017). The use of NIV during home care was positively correlated to shared care planning (P = 0.001). CONCLUSION: The continuous presence of a multi-specialist team may provide timely intervention, guarantee and trust on the part of the patient and family members.

The effectiveness of transnasal high flow nasal cannula in bronchoscopy under sedation: a systematic review and meta-analysis.

Background: The objective of this study was to conduct a systematic review and meta-analysis of the clinical application effects of transnasal high flow nasal cannula compared to other conventional modalities for oxygen therapy devices in patients undergoing bronchoscopy. Methods: A comprehensive literature search was conducted in multiple English databases, including PubMed, Web of Science, and Cochrane Library, to collect relevant studies on the application of high flow nasal cannula in patients undergoing bronchoscopy, and conducted a meta-analysis utilizing RevMan 5.4 software, following the predetermined inclusion and exclusion criteria. Results: A total of 12 studies meeting the inclusion criteria were included, involving 1,631 patients (HFNC group: n = 811, other oxygen therapy group: n = 820). The meta-analysis results demonstrated that HFNC significantly reduced the incidence of hypoxemia and improved the minimum oxygen saturation compared to conventional oxygen therapy (RR = 0.27, 95% CI: 0.18-0.41, p < 0.00001; MD = 6.09, 95% CI: 3.73-8.45, p < 0.00001). Furthermore, HFNC showed statistically significant differences when compared to non-invasive ventilation in terms of hypoxemia incidence (RR = 3.52, 95% CI: 1.13-10.97, p = 0.03) and minimum oxygen saturation (MD = -1.97, 95% CI: -2.97--0.98, p < 0.0001). In addition, HFNC resulted in significantly shorter surgical time and higher PaO2 at the end of the procedure compared to conventional oxygen therapy (MD = 1.53, 95% CI: 0.66-2.40, p = 0.0006; MD = 15.52, 95% CI: 10.12-20.92, p < 0.00001). However, there were no statistically significant differences observed in PaCO2, EtCO2, and MAP at the end of the procedure (MD = 1.23, 95% CI: -0.74-3.20, p = 0.22; MD = -0.35, 95% CI: -3.77-3.06, p = 0.84; MD = -0.54, 95% CI: -2.44-1.36, p = 0.58). Conclusion: When HFNC or NIV is utilized during the examination and treatment of bronchoscopy patients, both oxygenation modalities enhance oxygenation function and reduce the incidence of hypoxemia compared to conventional oxygen therapy. HFNC can be regarded as a viable alternative to NIV for specific high-risk patients undergoing bronchoscopy. It decreases the duration of bronchoscopy and improves the PaO2 levels at the end of the procedure, but does not significantly impact the PaCO2, EtCO2, and mean arterial pressure. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier 1414374462@qq.com.

Long-term cohort study of patients presenting with hypercapnic respiratory failure.

OBJECTIVE: We sought to describe the long-term prognosis for a population-based cohort of people with hypercapnic respiratory failure (HRF) and the associations between underlying diagnoses and the risks of death and rehospitalisation. METHODS: We performed a historical cohort study of all persons with HRF in the Liverpool local government area in New South Wales, Australia, in the 3-year period from 2013 to 2015. Cohort members were identified using arterial blood gas results from Liverpool Hospital demonstrating pH ≤7.45 and PaCO2 >45 mm Hg within 24 hours of presentation. Linked health data were obtained from statewide registries with a minimum follow-up period of 6 years. The primary outcomes were time to death from any cause and the standardised mortality ratio (SMR) which compares the observed to the expected number of deaths in the same population. Secondary outcomes were time to rehospitalisation and the associations between death and/or hospitalisation and underlying diagnoses. RESULTS: The cohort comprised 590 adults aged between 15 and 101 years. Overall, 415 (70.3%) participants died in the follow-up period. Among those who survived the index admission, the probability of survival at 1, 3 and 5 years was 81%, 59% and 45%, respectively. The overall SMR was 9.2 (95% CI 7.6 to 11.0), indicating a near 10-fold risk of death than otherwise expected for age. Most (91%) survivors experienced rehospitalisation, with median (IQR) time to readmission of 3.9 (1.2-10.6) months. Congestive cardiac failure and neuromuscular disease were associated with an increased risk of death, whereas chronic obstructive pulmonary disease and sleep disordered breathing increased the risk of rehospitalisation. CONCLUSIONS: HRF is associated with poor survival and high risk of rehospitalisation in the 5 years following an index event. The underlying disease appears to have some influence on overall survival and subsequent hospitalisations.

High-flow nasal oxygen therapy compared with conventional oxygen therapy in hospitalised patients with respiratory illness: a systematic review and meta-analysis.

BACKGROUND: High-flow nasal oxygen therapy (HFNO) is used in diverse hospital settings to treat patients with acute respiratory failure (ARF). This systematic review aims to summarise the evidence regarding any benefits HFNO therapy has compared with conventional oxygen therapy (COT) for patients with ARF. METHODS: Three databases (Embase, Medline and CENTRAL) were searched on 22 March 2023 for studies evaluating HFNO compared with COT for the treatment of ARF, with the primary outcome being hospital mortality and secondary outcomes including (but not limited to) escalation to invasive mechanical ventilation (IMV) or non-invasive ventilation (NIV). Risk of bias was assessed using the Cochrane risk-of-bias tool (randomised controlled trials (RCTs)), ROBINS-I (non-randomised trials) or Newcastle-Ottawa Scale (observational studies). RCTs and observational studies were pooled together for primary analyses, and secondary analyses used RCT data only. Treatment effects were pooled using the random effects model. RESULTS: 63 studies (26 RCTs, 13 cross-over and 24 observational studies) were included, with 10 230 participants. There was no significant difference in the primary outcome of hospital mortality (risk ratio, RR 1.08, 95% CI 0.93 to 1.26; p=0.29; 17 studies, n=5887) between HFNO and COT for all causes ARF. However, compared with COT, HFNO significantly reduced the overall need for escalation to IMV (RR 0.85, 95% CI 0.76 to 0.95 p=0.003; 39 studies, n=8932); and overall need for escalation to NIV (RR 0.70, 95% CI 0.50 to 0.98; p=0.04; 16 studies, n=3076). In subgroup analyses, when considering patients by illness types, those with acute-on-chronic respiratory failure who received HFNO compared with COT had a significant reduction in-hospital mortality (RR 0.58, 95% CI 0.37 to 0.91; p=0.02). DISCUSSION: HFNO was superior to COT in reducing the need for escalation to both IMV and NIV but had no impact on the primary outcome of hospital mortality. These findings support recommendations that HFNO may be considered as first-line therapy for ARF. PROSPERO REGISTRATION NUMBER: CRD42021264837.