Determinants of physical quality of life in patients with chronic thromboembolic pulmonary hypertension after treatment: Insights from invasive exercise stress test

BACKGROUND

Impaired quality of life (QoL) is prevalent among patients with chronic thromboembolic pulmonary hypertension (CTEPH) despite improved survival due to medical advances. We clarified the physical QoL of patients with CTEPH with mildly elevated pulmonary hemodynamics and evaluated its determinants using a database of patients with CTEPH evaluated for hemodynamics during exercise.

METHODS

The QoL was measured in 144 patients with CTEPH (age, 66 (58-73) years; men/women, 48/96) with mildly elevated mean pulmonary artery pressure (<30 mm Hg) at rest after treatment with balloon pulmonary angioplasty and/or pulmonary endarterectomy using the Short-Form 36 (SF-36) questionnaire. The enrolled patients were divided into 2 groups: physical component summary (PCS) scores in the SF-36 over 50 as PCS-good and those under 50 as PCS-poor.

RESULTS

The median PCS in SF-36 score was 43.4 (IQR 32.4-49.5) points. The PCS-poor group (n = 110) was older and had lower exercise capacity and SaO2 during exercise. PCS scores were correlated with 6-minute walk distance (rs=0.40, p < 0.001), quadriceps strength (rs=0.34, p < 0.001), peak VO2 (rs=0.31, p < 0.001), SaO2 at rest (rs=0.35, p < 0.001) and peak exercise (rs=0.33, p < 0.001), home oxygen therapy usage (rs=-0.28, p = 0.001), and pulmonary vascular resistance at peak exercise (rs=-0.26, p = 0.002).

CONCLUSIONS

The impairment of physical QoL was common in patients with CTEPH with improved hemodynamics; exercise capacity, hypoxemia, and hemodynamic status during exercise were related to the physical QoL.

High-flow nasal cannula during pulmonary rehabilitation for people with chronic obstructive pulmonary disease: A systematic review and meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is an increasingly concerning global public health issue due to its high burden of morbidity and mortality. Pulmonary rehabilitation (PR) is a comprehensive intervention to improve patients' physical and psychological conditions, commonly involving oxygen supplementation. The potential benefits of high-flow nasal cannula (HFNC) have recently sparked interest as oxygen therapy. In this context, this study aims to assess the effects of HFNC during the exercise training component of a PR program in people with COPD.

METHODS

Systematic review (CRD42022330929). We included randomised controlled trials (RCTs), including crossover RCTs with adults with stable COPD. We included trials using oxygen therapy with HFNC during the exercise training component of a PR programme.

PRIMARY OUTCOMES

disease-specific health-related quality of life (HRQoL), exercise capacity (EC) and adverse events.

SECONDARY OUTCOMES

treatment adherence, breathlessness and future exacerbations.

RESULTS

We included five studies with 300 participants with moderate to severe COPD. The certainty of the evidence was primarily low or very low for all outcomes of interest due to risk of bias, inconsistency or imprecision. HFNC has little to no difference in HRQoL (4 studies, 129 participants, MD 0.17, 95% CI -1.20 to 1.54; I2 50%). HFNC may result in little to no difference in EC (3 studies, 212 participants, mean difference 18.73, 95% CI -20.49 to 28.94; I2 56%), and we are uncertain about the effect of HFNC on breathlessness (4 studies; 244 participants, MD of -0.07, 95% CI -0.4 to 0.26; I2 63%). Only one study with 44 participants reported a participant's withdrawal because of progressive dyspnoea during lower limb exercise.

CONCLUSIONS

We are uncertain about the effect of HFNC during the exercise component of a PR programme in HRQoL, EC or dyspnoea compared to usual care or conventional supplementary oxygen. Non-domiciliary oxygen patients showed improvements in HRQoL, EC and dyspnoea.

Long-term cognitive and pulmonary functions following a lower versus a higher oxygenation target in the HOT-ICU and HOT-COVID trials: A protocol update

BACKGROUND

The Handling Oxygenation Targets in the Intensive Care Unit (HOT-ICU) trial was a multicentre, randomised, parallel-group trial of a lower oxygenation target (arterial partial pressure of oxygen [PaO2 ] = 8 kPa) versus a higher oxygenation target (PaO2  = 12 kPa) in adult ICU patients with acute hypoxaemic respiratory failure; the Handling Oxygenation Targets in coronavirus disease 2019 (HOT-COVID) tested the same oxygenation targets in patients with confirmed COVID-19. In this study, we aim to evaluate the long-term effects of these oxygenation targets on cognitive and pulmonary function. We hypothesise that a lower oxygenation target throughout the ICU stay may result in cognitive impairment, whereas a higher oxygenation target may result in impaired pulmonary function.

METHODS

This is the updated protocol and statistical analysis plan of two pre-planned secondary outcomes, the long-term cognitive function, and long-term pulmonary function, in the HOT-ICU and HOT-COVID trials. Patients enrolled in both trials at selected Danish sites and surviving to 1 year after randomisation are eligible to participate. A Repeatable Battery for the Assessment of Neuropsychological Status score and a full-body plethysmography, including diffusion capacity for carbon monoxide, will be obtained. The last patient is expected to be included in the spring of 2024.

CONCLUSION

This study will provide important information on the long-term effects of a lower versus a higher oxygenation target on long-term cognitive and pulmonary functions in adult ICU patients with acute hypoxaemic respiratory failure.

High-flow nasal cannula therapy for infants with bronchiolitis

BACKGROUND

Bronchiolitis is a common lower respiratory tract illness, usually of viral aetiology, affecting infants younger than 24 months of age and is the most common cause of hospitalisation of infants. It causes airway inflammation, mucus production and mucous plugging, resulting in airway obstruction. Effective pharmacotherapy is lacking and bronchiolitis is a major cause of morbidity and mortality. Conventional treatment consists of supportive therapy in the form of fluids, supplemental oxygen, and respiratory support. Traditionally, oxygen delivery is as a dry gas at 100% concentration via low-flow nasal prongs. However, the use of heated, humidified, high-flow nasal cannula (HFNC) therapy enables delivery of higher inspired gas flows of an air/oxygen blend, at 2 to 3 L/kg per minute up to 60 L/min in children. It can provide some level of continuous positive airway pressure (CPAP) to improve ventilation in a minimally invasive manner. This may reduce the need for invasive respiratory support, thus potentially lowering costs, with clinical advantages and fewer adverse effects.

OBJECTIVES

To assess the effects of HFNC therapy compared with conventional respiratory support in the treatment of infants with bronchiolitis.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, and Web of Science (from June 2013 to December 2022). In addition, we consulted ongoing trial registers and experts in the field to identify ongoing studies, checked reference lists of relevant articles, and searched for conference abstracts. Date restrictions were imposed such that we only searched for studies published after the original version of this review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs that assessed the effects of HFNC (delivering oxygen or oxygen/room air blend at flow rates greater than 4 L/minute) compared to conventional treatment in infants (< 24 months) with a clinical diagnosis of bronchiolitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently used a standard template to assess trials for inclusion and extract data on study characteristics, risk of bias elements, and outcomes. We contacted trial authors to request missing data. Outcome measures included the need for invasive respiratory support and time until discharge, clinical severity measures, oxygen saturation, duration of oxygen therapy, and adverse events.

MAIN RESULTS

In this update we included 15 new RCTs (2794 participants), bringing the total number of RCTs to 16 (2813 participants). Of the 16 studies, 11 compared high-flow to low-flow, and five compared high-flow to CPAP. These studies included infants less than 24 months of age as stated in our selection criteria. There were no significant differences in sex. We found that when comparing high-flow to low-flow oxygen therapy for infants with bronchiolitis there may be a reduction in the total length of hospital stay (mean difference (MD) -0.65 days, 95% confidence interval (CI) -1.23 to -0.06; P < 0.00001, I2 = 89%; 7 studies, 1951 participants; low-certainty evidence). There may also be a reduction in the duration of oxygen therapy (MD -0.59 days, 95% CI -1 to -0.18; P < 0.00001, I2 = 86%; 7 studies, 2132 participants; low-certainty evidence). We also found that there was probably an improvement in respiratory rate at one and 24 hours, and heart rate at one, four to six, and 24 hours in those receiving high-flow oxygen therapy when compared to pre-intervention baselines. There was also probably a reduced risk of treatment escalation in those receiving high-flow when compared to low-flow oxygen therapy (risk ratio (RR) 0.55, 95% CI 0.39 to 0.79; P = 0.001, I2 = 43%; 8 studies, 2215 participants; moderate-certainty evidence). We found no difference in the incidence of adverse events (RR 1.2, 95% CI 0.38 to 3.74; P = 0.76, I2 = 26%; 4 studies, 1789 participants; low-certainty evidence) between the two groups. The lack of comparable outcomes in studies comparing high-flow and CPAP, as well as the small numbers of participants, limited our ability to perform meta-analysis on this group.

AUTHORS' CONCLUSIONS

High-flow nasal cannula therapy may have some benefits over low-flow oxygen for infants with bronchiolitis in terms of a greater improvement in respiratory and heart rates, as well as a modest reduction in the length of hospital stay and duration of oxygen therapy, with a reduced incidence of treatment escalation. There does not appear to be a difference in the number of adverse events. Further studies comparing high-flow nasal cannula therapy and CPAP are required to demonstrate the efficacy of one modality over the other. A standardised clinical definition of bronchiolitis, as well as the use of a validated clinical severity score, would allow for greater and more accurate comparison between studies.

Obesity as a Risk Factor for Complications and Mortality in Individuals with SARS-CoV-2: A Systematic Review

This systematic review aimed to analyze the available studies that identified overweight and/or obesity as a risk factor for mortality, use of respiratory support, and changes in biochemical markers in adults hospitalized with SARS-CoV-2. The PubMed, Web of Science, and Scopus databases were searched using PRISMA guidelines until January 2024. The protocol was registered with PROSPERO (code: CRD42024501551). Of the 473 articles, only 8 met the inclusion criteria (e.g., adult individuals aged 18 or over diagnosed with COVID-19 individuals with overweight and/or obesity). In addition, the Downs and Black tool was used to assess the quality of the studies. The studies analyzed totaled 9782 adults hospitalized for COVID-19, indicating that overweight and obesity are present in more than half of adults. Diseases such as diabetes mellitus and hypertension are more prevalent in adults with obesity. The systematic review also highlighted that a higher incidence of respiratory support is related to a higher incidence of hospitalization in intensive care units and that adults with overweight and obesity have a higher risk of mortality from COVID-19. Biochemical markers such as procalcitinin, C-reactive protein, and interleukin-6 are associated with the severity of COVID-19 infection. This systematic review exposed overweight and/or obesity as a risk factor for worse COVID-19 disease, as well as for the need for intensive care, respiratory support, mortality, and changes in essential blood markers.

Physiological effect of high flow oxygen therapy measured by electrical impedance tomography in single-lung transplantation

In patients with chronic obstructive pulmonary disease (COPD), single lung transplantation (SLT) is sometimes performed as an alternative to bilateral lung transplantation due to limited organ availability. However, the postoperative management of SLT presents challenges, including complications related to the distinct compliance of each lung. This case report presents the case of a 65-year-old male patient who underwent SLT and was in the weaning period from mechanical ventilation. High-flow oxygen therapy (HFOT) was administered, and the physiological effects were measured using electrical impedance tomography (EIT). The results demonstrated that the application of HFOT increased air trapping and overdistention in the native lung without benefiting the transplanted lung. HFOT through a tracheostomy tube or nasal cannula resulted in a more heterogeneous distribution of ventilation, with increased end expiratory lung impedance, prolonged expiratory time constants, and an increase in silent spaces. The drop in tidal impedance after applying HFOT did not indicate hypoventilation but rather overdistention and air trapping in the native lung, while the transplanted lung showed evidence of hypoventilation. These findings suggest that HFOT may not be beneficial for SLT patients and could potentially worsen outcomes. However, due to the limited scope of this case report, further prospective studies with larger patient cohorts are needed to confirm these results.

Blood Pressure and Oxygen Targets on Kidney Injury After Cardiac Arrest

BACKGROUND

Acute kidney injury (AKI) represents a common and serious complication to out-of-hospital cardiac arrest. The importance of post-resuscitation care targets for blood pressure and oxygenation for the development of AKI is unknown.

METHODS

This is a substudy of a randomized 2-by-2 factorial trial, in which 789 comatose adult patients who had out-of-hospital cardiac arrest with presumed cardiac cause and sustained return of spontaneous circulation were randomly assigned to a target mean arterial blood pressure of either 63 or 77 mm Hg. Patients were simultaneously randomly assigned to either a restrictive oxygen target of a partial pressure of arterial oxygen (Pao2) of 9 to 10 kPa or a liberal oxygenation target of a Pao2 of 13 to 14 kPa. The primary outcome for this study was AKI according to KDIGO (Kidney Disease: Improving Global Outcomes) classification in patients surviving at least 48 hours (N=759). Adjusted logistic regression was performed for patients allocated to high blood pressure and liberal oxygen target as reference.

RESULTS

The main population characteristics at admission were: age, 64 (54-73) years; 80% male; 90% shockable rhythm; and time to return of spontaneous circulation, 18 (12-26) minutes. Patients allocated to a low blood pressure and liberal oxygen target had an increased risk of developing AKI compared with patients with high blood pressure and liberal oxygen target (84/193 [44%] versus 56/187 [30%]; adjusted odds ratio, 1.87 [95% CI, 1.21-2.89]). Multinomial logistic regression revealed that the increased risk of AKI was only related to mild-stage AKI (KDIGO stage 1). There was no difference in risk of AKI in the other groups. Plasma creatinine remained high during hospitalization in the low blood pressure and liberal oxygen target group but did not differ between groups at 6- and 12-month follow-up.

CONCLUSIONS

In comatose patients who had been resuscitated after out-of-hospital cardiac arrest, patients allocated to a combination of a low mean arterial blood pressure and a liberal oxygen target had a significantly increased risk of mild-stage AKI. No difference was found in terms of more severe AKI stages or other kidney-related adverse outcomes, and creatinine had normalized at 1 year after discharge.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03141099.

Linear versus Turbulent Airflow Tracheostomy Heat and Moisture Exchangers: A Crossover Study

OBJECTIVE

This study aimed to evaluate the impact of two tracheostomy heat and moisture exchangers (HMEs), namely the Shikani Oxygen HME™ (S-O2 HME, ball type, turbulent airflow) and Mallinckrodt Tracheolife II DAR HME (M-O2 HME; flapper type, linear airflow) on tracheobronchial mucosal health, oxygenation, humidification, and patient preference.

METHODS

A randomized cross-over study was conducted with HME-naïve long-term tracheostomy subjects at two academic medical centers. Bronchoscopy assessments of mucosal health were performed at baseline and day 5 of HME application, along with oxygen saturation (SpO2 ) and breathed air humidity at four oxygen flow rates (1, 2, 3, and 5 lpm). Patient preference was assessed on study conclusion.

RESULTS

Both HMEs were associated with improved mucosal inflammation and decreased mucus production (p < 0.0002), with greater improvements in the S-O2 HME group (p < 0.007). Both HMEs improved humidity concentration at each oxygen flow rate (p < 0.0001), without significant differences between groups. SpO2 was greater for the S-O2 HME versus the M-O2 HME across all measured oxygen flow rates (p = 0.003). At low oxygen flow rates (1 or 2 lpm), the SpO2 in the S-O2 HME group was similar to that of the M-O2 HME at higher oxygen flow rates (3 or 5 lpm; p = 0.6). Ninety percent of subjects preferred the S-O2 HME.

CONCLUSION

Tracheostomy HME uses correlated with improved indicators of tracheobronchial mucosal health, humidity, and oxygenation. The S-O2 HME outperformed the M-O2 HME with respect to tracheobronchial inflammation, SpO2 , and patient preference. Regular HME use by tracheostomy patients is recommended to optimize pulmonary health. Newer ball-type speaking valve technology additionally allows concomitant HME and speaking valve application.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:3422-3428, 2023.

Automated Oxygen Titration During CPAP and Noninvasive Ventilation in Healthy Subjects With Induced Hypoxemia

BACKGROUND

Automated oxygen titration to maintain a stable SpO2 has been developed for spontaneously breathing patients but has not been evaluated during CPAP and noninvasive ventilation (NIV).

METHODS

We performed a randomized controlled crossover, double-blind study on 10 healthy subjects with induced hypoxemia during 3 situations: spontaneous breathing with oxygen support, CPAP (5 cm H2O), and NIV (7/3 cm H2O). We conducted in random order 3 dynamic hypoxic challenges of 5 min (FIO2 0.08 ± 0.02, 0.11± 0.02, and 0.14 ± 0.02). For each condition, we compared automated oxygen titration and manual oxygen titration by experienced respiratory therapists (RTs), with the aim to maintain the SpO2 at 94 ± 2%. In addition, we included 2 subjects hospitalized for exacerbation of COPD under NIV and a subject managed after bariatric surgery with CPAP and automated oxygen titration.

RESULTS

The percentage of time in the SpO2 target was higher with automated compared with manual oxygen titration for all conditions, on average 59.6 ± 22.8% compared to 44.3 ± 23.9% (P = .004). Hyperoxemia (SpO2 > 96%) was less frequent with automated titration for each mode of oxygen administration (24.0 ± 24.4% vs 39.1 ± 25.3%, P < .001). During the manual titration periods, the RT made several changes to oxygen flow (5.1 ± 3.3 interventions that lasted 122 ± 70 s/period) compared to none during the automated titration to maintain oxygenation in the targeted SpO2 . Time in the SpO2 target was higher with stable hospitalized subjects in comparison with healthy subjects under dynamic-induced hypoxemia.

CONCLUSIONS

In this proof-of-concept study, automated oxygen titration was used during CPAP and NIV. The performances to maintain the SpO2 target were significantly better compared to manual oxygen titration in the setting of this study protocol. This technology may allow decreasing the number of manual interventions for oxygen titration during CPAP and NIV.

High-flow nasal cannula vs non-invasive ventilation in acute hypoxia: Propensity score matched study

RATIONALE

The optimal treatment for early hypoxemic respiratory failure is unclear, and both high-flow nasal cannula and non-invasive ventilation are used. Determining clinically relevant outcomes for evaluating non-invasive respiratory support modalities remains a challenge.

OBJECTIVES

To compare the effectiveness of initial treatment with high-flow nasal cannula versus non-invasive ventilation for acute hypoxemic respiratory failure.

METHODS

We conducted a retrospective cohort study of patients with acute hypoxemic respiratory failure treated with high-flow nasal cannula or non-invasive ventilation within 24 hours of Emergency Department arrival (1/2018-12/2022). We matched patients 1:1 using a propensity score for odds of receiving non-invasive ventilation. The primary outcome was major adverse pulmonary events (28-day mortality, ventilator-free days, non-invasive respiratory support hours) calculated using a Win Ratio.

MEASUREMENTS AND MAIN RESULTS

1,265 patients met inclusion criteria. 795 (62.8%) received high-flow oxygen and 470 (37.2%) received non-invasive ventilation. We propensity score matched 736/1,265 (58.2%) patients. There was no difference between non-invasive ventilation vs high-flow nasal cannula in 28-day mortality (17.7% vs 23.1%, p=0.08) or ventilator-free days (median [Interquartile Range]: 28 [25, 28] vs 28 [13, 28], p=0.50), but patients on non-invasive ventilation required treatment for fewer hours (median 7 vs 13, p< 0.001). Win Ratio for composite major adverse pulmonary events favored non-invasive ventilation (1.26, 95%CI 1.06-1.49, p< 0.001).

CONCLUSIONS

In this observational study of patients with acute hypoxemic respiratory failure, initial treatment with non-invasive ventilation was superior to high-flow nasal cannula for major pulmonary adverse events. Evaluation of composite outcomes is important in the assessment of respiratory support modalities.

Guidelines for high-flow nasal cannula oxygen therapy in neonates (2022)

High-flow nasal cannula (HFNC) oxygen therapy, which is important in noninvasive respiratory support, is increasingly being used in critically ill neonates with respiratory failure because it is comfortable, easy to setup, and has a low incidence of nasal trauma. The advantages, indications, and risks of HFNC have been the focus of research in recent years, resulting in the development of the application. Based on current evidence, we developed guidelines for HFNC in neonates using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). The guidelines were formulated after extensive consultations with neonatologists, respiratory therapists, nurse specialists, and evidence-based medicine experts. We have proposed 24 recommendations for 9 key questions. The guidelines aim to be a source of evidence and reference of HFNC oxygen therapy in clinical practice, and so that more neonates and their families will benefit from HFNC.

High-flow nasal cannula oxygen therapy for the treatment of acute respiratory failure secondary to SARS-CoV-2 pneumonia out of ICU

INTRODUCTION AND OBJECTIVES

High-flow nasal cannula oxygen therapy (HFNC) has been successfully used for the treatment of acute hypoxaemic respiratory failure (AHRF) secondary to SARS-CoV-2 pneumonia and being effective in reducing progression to invasive mechanical ventilation. The objective of this study was to assess the usefulness of HFNC on a hospital ward for the treatment of AHRF secondary to SARS-CoV-2 pneumonia and its impact on the need for intensive care unit (ICU) admission and endotracheal intubation. Other objectives include identifying potential physiological parameters and/or biomarkers for predicting treatment failure and assessing the clinical course and survival.

METHODS

Observational study based on data collected prospectively between March 2020 and February 2021 in a single hospital on patients diagnosed with AHRF secondary to SARS-CoV-2 pneumonia who received HFNC outside an ICU.

RESULTS

One hundred and seventy-one patients out of 1090 patients hospitalised for SARS-CoV-2 infection. HFNC was set as the ceiling of treatment in 44 cases; 12 survived (27.3%). Among the other 127 patients, intubation was performed in 25.9% of cases with a mortality of 11.8%. Higher creatinine levels (OR 1.942, 95% CI 1.04; 3.732; p = 0.036) and Comorbidity-Age-Lymphocyte-LDH (CALL) score (OR 1.273, 95% CI 1.033; 1.617; p = 0.033) were associated with a higher risk of intubation. High platelet count at HFNC initiation was predictive of good treatment response (OR 0.935, 95% CI 0.884; 0.983; p = 0.012).

CONCLUSIONS

HFNC outside an ICU is a treatment with high success rate in patients with AHRF secondary to SARS-CoV-2 pneumonia, including in patients in whom this therapy was deemed to be the ceiling of treatment.

Maternal Oxygen Administration during Labor: A Controversial Practice

Oxygen administration to the mother is commonly performed during labor, especially in the case of a non-reassuring fetal heart rate, aiming to increase oxygen diffusion through the placenta to fetal tissues. The benefits and potential risks are controversial, especially when the mother is not hypoxemic. Its impact on placental gas exchange and the fetal acid-base equilibrium is not fully understood and it probably affects the sensible placental oxygen equilibrium causing a time-dependent vasoconstriction of umbilical and placental vessels. Hyperoxia might also cause the generation of radical oxygen species, raising concerns for the developing fetal cells. Moreover, this practice affects the maternal cardiovascular system, causing alterations of the cardiac index, heart rate and vascular resistance, and unclear effects on uterine blood flow. In conclusion, there is no evidence that maternal oxygen administration can provide any benefit in the case of a non-reassuring fetal heart rate pattern, while possible collateral effects warn of its utilization. Oxygen administration during labor should be reserved for cases of maternal hypoxia.

Investigation and Analysis of the Current Status of Rationality and Standardization of Oxygen Therapy in Hospitalized Adult Patients

Objective

To investigate the rationality and standardization of oxygen therapy for hospitalized adult patients, so as to provide a basis for improving the quality of oxygen therapy care.

Methods

Self-designed "Inpatient Oxygen Therapy Status Questionnaire", using a cross-sectional survey, surveyed 185 oxygen inhalation patients in a tertiary general hospital from August 3-15, 2020, based on the formulation and promulgation of the Chinese Nursing Association The "Nursing care for adult patient with oxygen therapy" standard evaluates the rationality of clinical oxygen therapy implementation and the standardization of nursing measures.

Results

The reasonable rate of oxygen therapy for hospitalized adult patients was 19.46%, and the standardized rate of nursing measures was 54.52%. The reasonable and standardized rates of medical wards were higher than those of surgical and specialized wards, and were statistically significant (P<0.05). The incidence of complications of oxygen therapy was positively correlated with the rationality of oxygen therapy and the standardized data of nursing measures.

Conclusion

The clinical oxygen therapy nursing practice and the standard of "Nursing care for adult patient with oxygen therapy" are quite inadequate. There are differences in the quality of oxygen therapy in different wards. Nursing managers should strengthen training and management, standardize nursing behaviors, and improve the quality of oxygen therapy and ensure oxygen therapy for patients' safety.

Hemodynamic and respiratory support in pulmonary embolism: a narrative review

Pulmonary embolism is a common and potentially fatal disease, with a significant burden on health and survival. Right ventricular dysfunction and hemodynamic instability are considered two key determinants of mortality in pulmonary embolism, which can reach up to 65% in severe cases. Therefore, timely diagnosis and management are of paramount importance to ensure the best quality of care. However, hemodynamic and respiratory support, both major constituents of management in pulmonary embolism, associated with cardiogenic shock or cardiac arrest, have been given little attention in recent years, in favor of other novel advances such as systemic thrombolysis or direct oral anticoagulants. Moreover, it has been implied that current recommendations regarding this supportive care lack enough robustness, further complicating the problem. In this review, we critically discuss and summarize the current literature concerning the hemodynamic and respiratory support in pulmonary embolism, including fluid therapy, diuretics, pharmacological support with vasopressors, inotropes and vasodilators, oxygen therapy and ventilation, and mechanical circulatory support with veno-arterial extracorporeal membrane oxygenation and right ventricular assist devices, while also providing some insights into contemporary research gaps.

Use of high-flow nasal cannula oxygen therapy for patients with terminal cancer at the end of life

BACKGROUND

Few studies have focused on high-flow nasal cannula (HFNC) usage in the last few weeks of life. The aim of this study was to identify the status of HFNC use in patients with cancer at the end of life and the relevant clinical factors.

METHODS

We performed a retrospective cohort study in a tertiary hospital in the Republic of Korea. Among patients with cancer who died between 2018 and 2020, those who initiated HFNC within 14 days before death were included. Patients were categorized based on the time from HFNC initiation to death as imminent (<4 days) and non-imminent (≥4 days).

RESULTS

Among the 2191 deceased patients with terminal cancer, 329 (15.0%) were analyzed. The median age of the patients was 66 years, and 62.9% were male. The leading cause of respiratory failure was pneumonia (70.2%), followed by pleural effusion (30.7%) and aggravation of lung neoplasms (18.8%). Most patients were conscious (79.3%) and had resting dyspnea (76.3%) at HFNC initiation. Patients received HFNC therapy for a mean of 3.4 days in the last 2 weeks of life, and 62.6% initiated it within 4 days before death. Furthermore, female sex, no palliative care consultation, no advance statements in person on life-sustaining treatment, and no resting dyspnea were independently associated with the imminent use of HFNC.

CONCLUSIONS

Many patients with cancer started HFNC therapy at the point of imminent death. However, efforts toward goal-directed use of HFNC at the end-of-life stage are required.

Exposure to Arterial Hyperoxia During Extracorporeal Membrane Oxygenator Support and Mortality in Patients With Cardiogenic Shock

BACKGROUND

Exposure to hyperoxia, a high arterial partial pressure of oxygen (PaO2), may be associated with worse outcomes in patients receiving extracorporeal membrane oxygenator (ECMO) support. We examined hyperoxia in the Extracorporeal Life Support Organization Registry among patients receiving venoarterial ECMO for cardiogenic shock.

METHODS

We included Extracorporeal Life Support Organization Registry patients from 2010 to 2020 who received venoarterial ECMO for cardiogenic shock, excluding extracorporeal CPR. Patients were grouped based on PaO2 after 24 hours of ECMO: normoxia (PaO2 60-150 mmHg), mild hyperoxia (PaO2 151-300 mmHg), and severe hyperoxia (PaO2 >300 mmHg). In-hospital mortality was evaluated using multivariable logistic regression.

RESULTS

Among 9959 patients, 3005 (30.2%) patients had mild hyperoxia and 1972 (19.8%) had severe hyperoxia. In-hospital mortality increased across groups: normoxia, 47.8%; mild hyperoxia, 55.6% (adjusted odds ratio, 1.37 [95% CI, 1.23-1.53]; P<0.001); severe hyperoxia, 65.4% (adjusted odds ratio, 2.20 [95% CI, 1.92-2.52]; P<0.001). A higher PaO2 was incrementally associated with increased in-hospital mortality (adjusted odds ratio, 1.14 per 50 mmHg higher [95% CI, 1.12-1.16]; P<0.001). Patients with a higher PaO2 had increased in-hospital mortality in each subgroup and when stratified by ventilator settings, airway pressures, acid-base status, and other clinical variables. In the random forest model, PaO2 was the second strongest predictor of in-hospital mortality, after older age.

CONCLUSIONS

Exposure to hyperoxia during venoarterial ECMO support for cardiogenic shock is strongly associated with increased in-hospital mortality, independent from hemodynamic and ventilatory status. Until clinical trial data are available, we suggest targeting a normal PaO2 and avoiding hyperoxia in CS patients receiving venoarterial ECMO.

Ensayo Clínico Aleatorizado En Pacientes Covid- 19 Sobre El Efecto De La Fisioterapia Precoz En Su Acondicionamiento Físico

Introducción. La OMS recomienda las intervenciones tempranas de rehabilitación y movilización en pacientes hospitalizados por COVID-19. Los beneficios de la fisioterapia precoz, durante la estancia hospitalaria, no han sido probados en ensayos clínicos.

Objetivo: Evaluar los efectos de la fisioterapia precoz y educación para la salud en pacientes COVID-19 hospitalizados, en relación a los síntomas descritos en estudios previos, analizando diferencias entre grupos respecto a su acondicionamiento físico, necesidad de oxigenoterapia y estancia hospitalaria.

Metodología: Ensayo clínico aleatorizado con dos brazos, desarrollado en unidades de hospitalización y cuidados respiratorios intermedios, con pacientes COVID- 19. Incluidos 64 pacientes en el grupo experimental (implementación de un programa de Fisioterapia precoz tras 48-72h de ingreso) y 62 pacientes en el grupo control (tratamiento habitual del centro).

Variables sociodemográficas y clínicas: mMRC, oxigenoterapia, MRC-ss, 30 s-STST, FPM, Tinetti, FRAIL Scale y PCFS. Se evaluaron al ingreso, al alta y a los dos meses del alta.

Resultados: Los experimentales tuvieron menos días de ingreso y de oxigenoterapia convencional. Al alta, presentan menor riesgo de caída (72,9% vs 95,8%) y menor debilidad en MRC-ss (2,1% vs 14,6%). A los dos meses tenían menor fragilidad (5,0% vs 14,5%), mayor fuerza de prensión manual, menos disnea, mejores resultados en 30s-STST y menos limitaciones post-COVID (86,5% vs 96,4%).

Conclusión: La intervención de fisioterapia precoz en pacientes COVID-19 y la educación para la salud recibida, previene la debilidad muscular durante el ingreso, mejora el acondicionamiento físico al alta y a los dos meses y disminuye los días de estancia hospitalaria.ClinicalTrials.gov (NCT 05032885).

Unstable SpO2 in preterm infants: The key role of reduced ventilation to perfusion ratio

Introduction: Instability of peripheral oxyhemoglobin saturation (SpO₂) in preterm infants is correlated with late disability and is poorly understood. We hypothesised that a reduced ventilation to perfusion ratio (V_A/Q) is the key predisposing factor for SpO₂ instability. Methods: We first used a mathematical model to compare the effects of reduced V_A/Q or shunt on SaO₂ stability (SaO₂ and SpO₂ are used for model and clinical studies respectively). Stability was inferred from the slope of the SaO₂ vs. inspired oxygen pressure (P _IO₂) curve as it intersects the 21 kPa P _IO₂ line (breathing air). Then, in a tertiary neonatal intensive care unit, paired hourly readings of SpO₂ and P _IO₂ were recorded over a 24 h period in week old extremely preterm infants. We noted SpO₂ variability and used an algorithm to derive V_A/Q and shunt from the paired SpO₂ and P _IO₂ measurements. Results: Our model predicted that when V_A/Q < 0.4, a 1% change in P _IO₂ results in >8% fluctuation in SaO₂ at 21 kPa P _IO₂. In contrast, when a 20% intrapulmonary shunt was included in the model, a 1% change in P _IO₂ results in <1% fluctuation in the SaO₂. Moreover, further reducing the V_A/Q from 0.4 to 0.3 at 21 kPa P _IO₂ resulted in a 24% fall in SaO₂. All 31 preterm infants [mean gestation (±standard deviation) 26.2 (±1) week] had V_A/Q < 0.74 (normal >0.85) but only two infants had increased shunt at 1.1 (±0.5) weeks' postnatal age. Median (IQR) SpO₂ fluctuation was 8 (7)%. The greatest SpO₂ fluctuations were seen in infants with V_A/Q < 0.52 (n = 10): SpO₂ fluctuations ranged from 11%-17% at a constant P _IO₂ when V_A/Q < 0.52. Two infants had reduced V_A/Q and increased shunt (21% and 27%) which resolved into low V_A/Q after 3-6 h. Discussion: Routine monitoring of P _IO₂ and SpO₂ can be used to derive a hitherto elusive measure of V_A/Q. Predisposition to SpO₂ instability results from reduced V_A/Q rather than increased intrapulmonary shunt in preterm infants with cardiorespiratory disease. SpO₂ instability can be prevented by a small increase in P _IO₂.

Effectiveness of high-flow nasal cannula therapy on clinical outcomes in adults with COVID-19: A systematic review

Introduction/Background

Coronavirus disease 2019 (COVID-19) has high transmissibility and mortality rates. High-flow nasal cannula therapy (HFNC) might reduce the need for orotracheal intubation, easing the burden on the health system caused by COVID-19. The objective of the present study was to examine the effectiveness of HFNC in adult patients hospitalized with COVID-19. Specifically, the present study explores the effects of HFNC on rates of mortality, intubation and intensive care units (ICU) length of stay. The present study also seeks to define predictors of success and failure of HFNC.

Methods

A systematic literature search was conducted in the PubMed, EMBASE and SCOPUS databases, and the study was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Study quality was assessed using the National Heart, Lung, and Blood Institute's Study Quality Assessment Tools.

Results

The search identified 1,476 unique titles; 95 articles received full-text reviews and 40 studies were included in this review. HFNC was associated with a reduction in the rate of orotracheal intubation, notably when compared to conventional oxygen therapy. Studies reported inconsistency in whether HFNC reduced ICU length of stay or mortality rates. Among the predictors of HFNC failure/success, a ratio of oxygen saturation index of approximately 5 or more was associated with HFNC success.

Conclusion

In adult patients hospitalized with COVID-19, HFNC may prove effective in reducing the rate of orotracheal intubation. The ratio of the oxygen saturation index was the parameter most examined as a predictor of HFNC success. Low-level research designs, inherent study weaknesses and inconsistent findings made it impossible to conclude whether HFNC reduces ICU length of stay or mortality. Future studies should employ higher level research designs.

A Volunteer Crossover Feasibility Study to Compare Standard Oxygen Cannula Used at High-Flow to Proprietary High-Flow Humidified Nasal Oxygen Systems

BACKGROUND AND AIM

Supplemental oxygen is routinely administered to patients prior to and during induction of general anesthesia and sedation. This increases the fraction of oxygen in the lungs, increases oxygen delivery, and increases the time to oxygen desaturation. Proprietary Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) systems, which deliver warmed and humidified oxygen, have been extensively researched in the perioperative and critical care setting and have been shown to significantly prolong time to desaturation and as a means of ventilatory support. The use of traditional nasal oxygen cannula used at maximum flow rates is currently used in short bursts as it is poorly tolerated. There is however a dearth of data examining the use of this technique. We hypothesized that traditional nasal oxygen cannulae used at maximum flow rates can deliver oxygen as effectively as THRIVE in this setting.

METHODS

We designed a crossover volunteer feasibility study. The participants were 10 healthy anesthetists. We compared the two methods of oxygen delivery by measuring transcutaneous oxygen measurement and pharyngeal oxygen concentration. Comfort and noise levels were recorded. The aforementioned parameters were compared between the two groups.

RESULTS

We observed that a standard oxygen cannula used at high flows delivers comparable oxygen delivery and tissue oxygenation performance to proprietary THRIVE systems. However, they are less comfortable and make more noise.

DISCUSSION

To the authors' knowledge this study is the first to study the oxygen delivery of traditional nasal oxygen cannula used at maximum flow rates and make comparisons to the well-studied THRIVE technique. While similar transcutaneous partial pressure of oxygen and pharyngeal gas concentrations were observed with both techniques, the standard cannulae were deemed to be a lot less comfortable than THRIVE and made a lot more noise which likely limit the utility of this technique outside of short bursts.

CONCLUSION

In this study, a standard nasal oxygen cannula used at high flows achieved similar oxygen delivery to THRIVE at the expense of poor comfort and increased noise.

Assessment of the efficacy of a video-based hybrid teaching module of oxygen therapy and critical care area troubleshooting in nursing professionals managing COVID-19 patients

BACKGROUND

Video-based teaching has become rapidly popular during the coronavirus disease 2019 (COVID-19) pandemic. The current study aimed to assess the efficacy of a hybrid video-based teaching module of oxygen therapy and critical care troubleshooting in nursing professionals managing COVID-19 patients in our institute.

MATERIALS AND METHODS

A retrospective analytical study (pretest and posttest design) was conducted in our medical education department in March 2022 using the data from a workshop conducted on oxygen therapy and critical care area troubleshooting during COVID-19 patient management for 296 nursing professionals. A hybrid video-based teaching module was used. Pretest and posttest data were compared along with subgroup analysis. P value <0.05 was considered significant.

RESULTS

Posttest scores were significantly higher than the baseline scores in the overall group as well as in all subgroups (P < 0.001). Subgroup comparisons revealed no significant difference in mean baseline pretest and posttest scores in male versus female participants. Baseline pretest scores (P = 0.02) and posttest scores (P = 0.08) were lower in the nurses of the noncritical areas compared to critical area nurses. Mean improvement in posttest score compared to baseline score was similar between all groups.

CONCLUSION

Hybrid technique involving both video aspects and in-person teacher presence for demonstration or troubleshooting improves perceived knowledge in nursing professionals with some prior formal training and may be superior to the conventional only didactic/lecture-based demonstrations, especially in the context of imparting rapid training during pandemics or similar urgent situations.

Home High-Flow Nasal Cannula Oxygen Therapy for Stable Hypercapnic COPD: A Randomized Clinical Trial

Rationale: The long-term effects of using a high-flow nasal cannula for chronic hypercapnic respiratory failure caused by chronic obstructive pulmonary disease remain unclear. Objectives: To assess whether long-term high-flow nasal cannula use reduces the number of exacerbations and improves other physiological parameters in patients with chronic hypercapnic respiratory failure caused by chronic obstructive pulmonary disease. Methods: We enrolled 104 participants (aged ⩾40 yr) with daytime hypercapnia (Global Initiative for Chronic Obstructive Lung Disease stages 2-4) receiving long-term oxygen therapy (⩾16 h/d for ⩾1 mo) and randomly assigned them to high-flow nasal cannula/long-term oxygen therapy and long-term oxygen therapy groups. The primary endpoint was the moderate or severe exacerbation rate. We compared changes from baseline in arterial blood gas values, peripheral oxygen saturation, pulmonary function, health-related quality-of-life scores, and the 6-minute-walk test. Measurements and Main Results: High-flow nasal cannula use significantly reduced the rate of moderate/severe exacerbations (unadjusted mean count 1.0 vs. 2.5, a ratio of the adjusted mean count between groups [95% confidence interval] of 2.85 [1.48-5.47]) and prolonged the duration without moderate or severe exacerbations. The median time to first moderate or severe exacerbation in the long-term oxygen therapy group was 25 (14.1-47.4) weeks; this was not reached in the high-flow nasal cannula/long-term oxygen therapy group. High-flow nasal cannula use significantly improved health-related quality of life scores, peripheral oxygen saturation, and specific pulmonary function parameters. No safety concerns were identified. Conclusions: A high-flow nasal cannula is a reasonable therapeutic option for patients with stable hypercapnic chronic obstructive pulmonary disease and a history of exacerbations. Clinical trial registered with www.umin/ac.jp (UMIN000028581) and www.clinicaltrials.gov (NCT03282019).

High-flow nasal oxygenation during gastrointestinal endoscopy. Systematic review and meta-analysis

Background

The use of high-flow nasal oxygen (HFNO) has the potential to improve patient safety by limiting hypoxaemia during gastrointestinal endoscopy. The degree of benefit is not adequately established.

Methods

English language literature searches of PubMed, Scopus, Web of Science, and Cochrane Library electronic databases were performed to identify randomised controlled trials comparing HFNO and conventional oxygen therapy (COT) for patients undergoing gastrointestinal endoscopy under deep sedation. The primary endpoint was the incidence of hypoxic events observed during endoscopic procedures. The secondary endpoints were the incidence of recourse to rescue manoeuvres, procedure interruption, and adverse events. A meta-analysis and a post hoc trial sequence analysis were performed.

Results

A total of 2867 patients from six randomised controlled trials were considered. Desaturation was observed in 5.2% and 27.2% of patients receiving HFNO and COT, respectively. Desaturation <90% was observed in 1.8% and 12.6% of the patients receiving HFNO and COT, respectively. In the subgroup analysis, desaturation occurrence was lower during HFNO than during COT in non-obese patients (2.2% vs 25.2%) and obese patients (22.9% vs 43.3%). Desaturation occurrence was lower during maximum (3.6% vs 26.9%) and minimum (15.9% vs 29.8%) HFNO therapy than during COT. HFNO showed a lower recurrence to rescue manoeuvres rate (4.7% vs 34.3%), a lower procedure interruption rate (0.4% vs 6.7%), and a lower adverse events rate (18.7% vs 21%) than COT. A high level of heterogeneity between the studies precluded confidence in drawing inference from the meta-analysis.

Conclusions

The evidence reviewed suggests that compared with COT, HFNO has fewer hypoxaemic events during gastrointestinal endoscopy, but this may not apply to all patients and clinical scenarios.

Life-Space Mobility of Subjects With COPD on Long-Term Oxygen Therapy Delivered by Non-Portable Devices

BACKGROUND

Mobility is human body movement in all its forms, including bed-to-chair transfer, walking, daily tasks, participating in work and social functions, exercising, and using public transport. The mobility of people living with COPD is affected negatively by the disease symptoms. However, limited data are available on the life-space mobility in people with COPD on long-term oxygen therapy (LTOT). This study aimed to explore the life-space mobility in subjects with COPD on LTOT and verify whether life-space mobility is associated with comorbidities and symptoms, activity in daily life, exercise capacity performance, and quality of life.

METHODS

This cross-sectional study enrolled 61 subjects with COPD on LTOT (73.0 ± 8.8 y, FEV1 41.7 ± 16.0% predicted, on LTOT for 2.8 ± 3.3 y). Life-space mobility (Life-Space Assessment), LTOT usage time, comorbidities (Charlson comorbidity index), need for support from a caregiver, exercise capacity (6-min step test), dyspnea (modified Medical Research Council scale), activities of daily living (ADLs, Katz scale), and health-related quality of life (EuroQol 5-Dimension Questionnaire) were assessed.

RESULTS

Mobility restriction was identified in 90% of participants. Life-space mobility was negatively associated with the number of comorbidities (rs = -0.31, P = .02), dyspnea symptom (rs = -0.60, P < .001), and positively associated with basic ADLs performance (rs = 0.59, P < .001) and exercise capacity (rs = 0.49, P < .001). Dyspnea and exercise capacity were independent predictors of vital space mobility.

CONCLUSIONS

Subjects with COPD on LTOT had limited life-space mobility. Interventions to reduce dyspnea and improve exercise capacity should be prioritized to increase this population's domestic and community mobility.

Caregiver Burden Is Associated With the Physical Function of Individuals on Long-Term Oxygen Therapy

BACKGROUND

The influence of physical function of individuals on long-term oxygen therapy (LTOT) on caregiver burden is underexplored. This study investigated the association of caregiver burden with physical function of individuals on LTOT and the association between caregiver's burden and quality of life.

METHODS

This was a cross-sectional study. Informal caregivers were assessed for burden using the Caregiver Burden Inventory (CBI), the European Quality of Life 5 Dimension questionnaire index (EQ-5D index) and its Visual Analog Scale (EQ-VAS). Physical function of subjects on LTOT was assessed by dyspnea, activities of daily living (ADLs), and mobility. Univariate and multivariate linear regression models were explored.

RESULTS

Fifty-four caregivers (54.7 ± 16.1 y, 74.1% female) were included. CBI total score was correlated with subject's dyspnea (r = 0.369, P = .006) and ADLs (r = 0.300, P = .03). In the multivariate regression models, subject's physical function limitation due to dyspnea explained 26.4% of the CBI total score variance (P = .005). In the CBI dimension analysis, the time-dependence caregiver burden was correlated with subject's dyspnea (r = 0.335, P = .01), ADLs (r = 0.436, P = .001), and mobility (r = -0.415, P = .002). CBI developmental and physical caregiver burden were correlated with dyspnea (r = 0.309, P = .02; r = 0.363, P = .007) and ADLs (r = 0.274, P = .045; r = 0.299, P = .03). Emotional caregiver burden was correlated with dyspnea (r = 0.333, P = .01). Higher CBI total score was correlated with worse quality of life on EQ-5D index (r_s= -0.374, P = .005) and EQ-VAS (r_s= -0.494, P = .001) in caregivers.

CONCLUSIONS

Increased caregiver burden was associated with higher physical limitation due to dyspnea and dependence in ADLs of individuals on LTOT. The increased burden was associated with a worse caregiver's quality of life.

Cognitive Function and the Ability to Operate Long-Term Oxygen Therapy Equipment: An Exploratory Study

Chronic respiratory disease patients with severe hypoxia receive long-term oxygen therapy (LTOT). The proper operation of LTOT equipment is essential for continuing treatment. This exploratory study investigated the relationship between cognitive impairment as a comorbidity in patients receiving LTOT and their ability to operate the LTOT equipment. The study measured responses to questions based on the ability of participants to operate the equipment and applied the Montreal Cognitive Assessment (MoCA). The ability of groups with MoCA scores ≤ 25 and >25 to operate LTOT equipment was compared to confirm the correlation between MoCA and ability to operate the equipment. An aggregate of 60 participants receiving LTOT were recruited, of whom 45 (75%) were MoCA score ≤ 25. The group of MoCA score ≤ 25 demonstrated a lower ability to operate LTOT equipment than group of MoCA score > 25 (p = 0.012). Additionally, a correlation was found between the ability to operate LTOT equipment and MoCA (rs = 0.743, p < 0.001). The results indicated that the group of MoCA score ≤ 25 indicated a lower ability to operate LTOT equipment than that of MoCA score > 25. Cognitive impairment in patients receiving LTOT can affect their ability to operate LTOT equipment.

Oxygen Therapy in Cluster Headache, Migraine, and Other Headache Disorders

Oxygen therapy (OT) can relieve head pain in certain primary headache disorders, including cluster headache (CH). The exact underlying mechanism is currently uncertain, but suggested mechanisms include inhibition of the trigeminoautonomic reflex, modulation of neurotransmitters, and cerebral vasoconstriction. OT is the standard for acute treatment of CH, but patients with CH often experience considerable difficulties accessing home OT due to problems with insurance coverage. Inhalation of 100% oxygen at 6–12 L/min for 15–30 min using a non-rebreather face mask is one of the most effective acute therapies for CH, but several trials have indicated the superiority of higher oxygen flow rates of up to 15 L/min and/or using a demand-valve oxygen mask that can produce very high flow rates. Two randomized controlled trials have demonstrated the efficacy of OT in migraine, but obtaining reliable evidence is considered difficult because of different inhalation protocols, varying outcome measures, and small samples. There are some reports on the efficacy of OT as an adjuvant therapy in hypnic headache, primary headache in the emergency department, and even postdural puncture headache. The goal of this review article is to expand the knowledge regarding the use of oxygen in the treatment of headache disorders.

Changes in Ventilation Practices for Bronchiolitis in the Hospital Ward and Need for ICU Transfer over the Last Decade

There is limited evidence of the potential benefits of the use of high-flow nasal cannula (HFNC) for the management of bronchiolitis in the ward. Our aim is to describe the ventilation trends for bronchiolitis in our hospital along with the introduction of an HFNC ward protocol and to determine the need for respiratory support escalation and transfer to an intensive care unit (ICU). A retrospective analytical observational study of children < 12 months old requiring admission for a first RSV bronchiolitis episode in a single centre from January 2009 to December 2018. The sample was divided into four groups according to the type of respiratory support that would ensure the clinical stability of the infants on admission. A total of 502 infants were recruited. The total number and percentage of patients admitted in the ward grew progressively over time. Simultaneously, there was an increase in HFNC and, paradoxically, an increase in ICU transfers. The risk of failure was higher for those who required HFNC or CPAP for clinical stabilisation in the first 12 h after admission. Moreover, the risk of failure was also higher in children with standard oxygen therapy promptly escalated to HFNC, especially if they had atelectasis/viral pneumonia, coinfections or a history of prematurity. Despite the limitations of a retrospective analysis, our study reflects usual clinical practice and no correlation was found between the usage of HFNC and a shorter length of hospital stay or less time spent on oxygen therapy.

Sedentary Time and Cognitive Impairment in Patients Using Long-Term Oxygen Therapy: A Cross-Sectional Study

Physical inactivity is a predictor of death in patients with chronic respiratory disease. Cognitive impairment is common among patients with chronic respiratory disease. However, the association between sedentary time and cognitive impairment in patients with chronic respiratory disease using long-term oxygen therapy is unclear. This study aimed to determine the relationship between sedentary time and cognitive impairment in patients on long-term oxygen therapy. This cross-sectional study included 96 patients with chronic respiratory disease on long-term oxygen therapy (mean age 77.3 years; female, 22%). The primary outcomes measured were sedentary time (Japanese version of the International Physical Activity Questionnaire Short Form), cognitive function (Montreal Cognitive Assessment), and dyspnea (modified Medical Research Council scale). The factors associated with sedentary time were confirmed by multiple regression analysis. The median sedentary time was 600.0 min. The median Montreal Cognitive Assessment score was 24.0 points, and 67 (70%) patients had mild cognitive impairment. In multiple regression analysis, sedentary time was associated with dyspnea (β = 0.397, p < 0.001) and cognitive function (β = −0.239, p = 0.020). This study indicates that sedentary time in patients on long-term oxygen therapy was associated with dyspnea and cognitive impairment.

The longitudinal course of pediatric acute respiratory distress syndrome and its time to resolution: A prospective observational study

BACKGROUND

The longitudinal course of patients with pediatric acute respiratory distress syndrome (PARDS) is not well described. In this study, we describe the oxygenation index (OI) and oxygen saturation index (OSI) in mild, moderate, and severe PARDS over 28 days and provide pilot data for the time to resolution of PARDS (T _res), as a short-term respiratory-specific outcome, hypothesizing that it is associated with the severity of PARDS and clinical outcomes.

METHODS

This prospective observational study recruited consecutive patients with PARDS. OI and OSI were trended daily over 28 days. T _res (defined as OI < 4 or OSI < 5.3 on 2 consecutive days) were described based on PARDS severity and analyzed with Poisson and logistic regression to determine its association with conventional outcomes [mechanical ventilation (MV) duration, intensive care unit (ICU) and hospital length of stay, 28-day ventilator-free days (VFD), and 28-day ICU-free days (IFD)].

RESULTS

There were 121 children included in this study, 33/121(27.3%), 44/121(36.4%), and 44/121(36.4%) in the mild, moderate, and severe groups of PARDS, respectively. OI and OSI clearly differentiated mild, moderate, and severe groups in the first 7days of PARDS; however, this differentiation was no longer present after 7days. Median T _res was 4 (interquartile range: 3, 6), 5 (4, 7), and 7.5 (7, 11.5) days; p < 0.001 for the mild, moderate, and severe groups of PARDS, respectively. T _res was associated with increased MV duration, ICU and hospital length of stay, and decreased VFD and IFD.

CONCLUSION

The oxygenation defect in PARDS took progressively longer to resolve across the mild, moderate, and severe groups. T _res is a potential short-term respiratory-specific outcome, which may be useful in addition to conventional clinical outcomes but needs further validation in external cohorts.

Interactions in clinical trials: Protocol and statistical analysis plan for an explorative study of four randomized ICU trials on use of pantoprazole, oxygenation targets, haloperidol and intravenous fluids

BACKGROUND

Intensive care unit (ICU) patients receive numerous interventions, but knowledge about potential interactions between these interventions is limited. Co-enrolment in randomized clinical trials represents a unique opportunity to investigate any such interactions. We aim to assess interactions in four randomized clinical trials with overlap in inclusion periods and patient populations.

METHODS

This protocol and statistical analysis plan describes a secondary explorative analysis of interactions in four international ICU trials on pantoprazole, oxygenations targets, haloperidol and intravenous fluids, respectively. The primary outcome will be 90-day all-cause mortality. The secondary outcome will be days alive and out of hospital in 90 days after randomization. All patients included in the intention-to-treat populations of the four trials will be included. Four co-primary analyses will be conducted, one with each of the included trials as reference using a logistic regression model adjusted for the reference trial's stratification variables and for the co-interventions with interactions terms. The primary analytical measure of interest will be the analyses' tests of interaction. A p-value below .05 will be considered statically significant. The stratification variable- and co-intervention-adjusted effect estimates will be reported with 95% confidence intervals without adjustments for multiplicity.

CONCLUSION

This exploratory analysis will investigate the presence of any interactions between pantoprazole, oxygenation targets, haloperidol and amount of intravenous fluids in four international ICU trials using co-enrolment. Assessment of possible interactions represents valuable information to guide the design, statistical powering and conduct of future trials.

Oxygenation targets in ICU patients with COVID-19: A post hoc subgroup analysis of the HOT-ICU trial

Background

Supplemental oxygen is the key intervention for severe and critical COVID‐19 patients. With the unstable supplies of oxygen in many countries, it is important to define the lowest safe dosage.

Methods

In spring 2020, 110 COVID‐19 patients were enrolled as part of the Handling Oxygenation Targets in the ICU trial (HOT‐ICU). Patients were allocated within 12 h of ICU admission. Oxygen therapy was titrated to a partial pressure of arterial oxygen (PaO₂) of 8 kPa (lower oxygenation group) or a PaO₂ of 12 kPa (higher oxygenation group) during ICU stay up to 90 days. We report key outcomes at 90 days for the subgroup of COVID‐19 patients.

Results

At 90 days, 22 of 54 patients (40.7%) in the lower oxygenation group and 23 of 55 patients (41.8%) in the higher oxygenation group had died (adjusted risk ratio: 0.87; 95% confidence interval, 0.58–1.32). The percentage of days alive without life support was significantly higher in the lower oxygenation group (p = 0.03). The numbers of severe ischemic events were low with no difference between the two groups. Proning and inhaled vasodilators were used more frequently, and the positive end‐expiratory pressure was higher in the higher oxygenation group. Tests for interactions with the results of the remaining HOT‐ICU population were insignificant.

Conclusions

Targeting a PaO₂ of 8 kPa may be beneficial in ICU patients with COVID‐19. These results come with uncertainty due to the low number of patients in this unplanned subgroup analysis, and insignificant tests for interaction with the main HOT‐ICU trial.

Trial registration number: ClinicalTrials.gov number, NCT03174002.

Date of registration: June 2, 2017.

Social Participation and Associated Factors in Individuals with Chronic Obstructive Pulmonary Disease on Long-Term Oxygen Therapy

Long-term oxygen therapy (LTOT) reduces hypoxaemia and mitigate systemic alterations in chronic obstructive pulmonary disease (COPD), however, it is related to inactivity and social isolation. Social participation and its related factors remain underexplored in individuals on LTOT. This study investigated social participation in individuals with COPD on LTOT and its association with dyspnoea, exercise capacity, muscle strength, symptoms of anxiety and depression, and quality of life. The Assessment of Life Habits (LIFE-H) assessed social participation. The modified Medical Research Council dyspnoea scale, the 6-Minute Step test (6MST) and handgrip dynamometry were used for assessments. In addition, participants responded to the Hospital Anxiety and Depression Scale (HADS) and the Chronic Respiratory Questionnaire (CRQ). Correlation coefficients and multivariate linear regression analyses were applied. Fifty-seven participants with moderate to very severe COPD on LTOT were included (71 ± 8 years, FEV₁: 40 ± 17%predicted). Social participation was associated with dyspnoea (r_s=-0.46, p < 0.01), exercise capacity (r = 0.32, p = 0.03) and muscle strength (r = 0.25, p = 0.05). Better participation was also associated with fewer depression symptoms (r_s=-0.40, p < 0.01) and a better quality of life (r = 0.32, p = 0.01). Dyspnoea was an independent predictor of social participation (p < 0.01) on regression models. Restricted social participation is associated with increased dyspnoea, reduced muscle strength and exercise capacity. Better participation is associated with fewer depression symptoms and better quality of life in individuals with COPD on LTOT.

The Portuguese Model of Home Respiratory Care: Healthcare Professionals' Perspective

Patients' and carers' views regarding the Portuguese model of home respiratory care were recently described, yet the complementary perspective of healthcare professionals (HCPs) is still to be investigated. Thus, this study explored HCPs experience in the management of patients needing home respiratory therapies (HRT), and their perspective about the Portuguese model. A phenomenological descriptive study, using focus groups, was carried out with 28 HCPs (median 42 y, 68% female) with distinct backgrounds (57% pulmonologists, 29% clinical physiologists, 7% physiotherapists, 7% nurses). Three focus groups were conducted in three regions of Portugal. Thematic analysis was performed by two independent researchers. HCPs have in general a positive view about the organization of the Portuguese model of home respiratory care, which was revealed in four major topics: Prescription (number of references, n = 171), Implementation and maintenance (n = 162), Carer involvement (n = 65) and Quality of healthcare (n = 247). Improvements needed were related to patients' late referral, HRT prescription (usability of the medical electronic prescription system and renewals burden), patients' education, access to hospital care team, lack of multidisciplinary work and articulation between hospital, primary and home care teams. This study describes the perspective of HCPs about the Portuguese model of home respiratory care and identifies specific points where improvements and reflections are needed. This knowledge may be useful to decision makers improve the current healthcare model.

Velocity-based target flow rate for high-flow nasal cannula oxygen therapy

BACKGROUND

The aim of this study was to assess retrospectively whether the average inspiratory flow velocity-based initial flow rate in high-flow nasal cannula (HFNC) therapy could be well tolerated and safely used for infants and children hospitalized with moderate to severe respiratory failure.

METHODS

Thirty-three patients without underlying diseases (22 males; 67%), hospitalized to receive HFNC therapy for infection-related respiratory failure, were analyzed. The median age was 2 months (interquartile range, 1 month to 1 year). Patients with dyspnea and carbon dioxide partial pressure (pCO₂ ) >50 mmHg or venous blood pH <7.320, combined with pulse oximetry arterial oxygen saturation <92%, were included. We set target flow rates calculated from the average inspiratory flow velocity, starting at the actual initial flow rates, and these were subsequently adjusted if necessary.

RESULTS

One patient could not tolerate the cannula. Of the remaining 32 patients, 81% (n = 26) had an actual initial flow rate within 1 L of the target flow rate; these patients were evaluated for changes in the fraction of inspired oxygen (FITarget flow rate tableO₂ ), pH, and pCO₂ values after 24 h. Three patients required a higher fraction of inspired oxygen, one showed a persistent pH < 7.320, and seven exhibited pCO₂ >50 mmHg. No patient required non-invasive positive-pressure ventilation, and one required intubation. Pneumothorax was not reported in any patient.

CONCLUSIONS

The average inspiratory flow velocity-based initial flow rate was well-tolerated without sedation, and there were no severe complications. Starting at this flow rate would improve the use of HFNC therapy in the pediatric ward, possibly reducing the need for more invasive modes of ventilation.

The effect of high flow nasal oxygen therapy in intensive care units: a systematic review and meta-analysis

BACKGROUND

High flow nasal oxygen (HFNO) therapy has been widely used in intensive care units (ICU); however, its efficacy remains inconclusive. This systematic review and meta-analysis aimed to compare the efficacy of HFNO therapy with th at of alternative noninvasive oxygen therapies such as conventional oxygen therapy (COT) and noninvasive ventilation (NIV) in ICU.

METHODS

A Pubmed, Embase, Web of Science, Cochrane Library database search was performed in March 2020. Results: The meta-analysis ultimately included 17 clinical studies. Compared with the overall effect of COT and NIV, HFNO was associated with a low incidence of pneumonia (95% CI: 0.6-0.99, P = 0.04) and improvement in lowest pulse oxygen saturation (SpO₂) during oxygenation (95% CI: 0.02-1.61; P = 0.04). However, no differences were detected in the following outcomes: length of ICU stay, the rate of intubation or reintubation, mortality at day 28, hospital mortality, and SpO₂ at the end of oxygen therapy (all P > 0.05).

CONCLUSIONS

In adult patients in ICU, HFNO may improve oxygenation and decrease pneumonia rate without affecting the length of ICU stay, intubation or reintubation rate, mortality, and SpO₂ at the end of oxygen therapy.

The Oxygen project: a prospective study to assess the effectiveness of a targeted intervention to improve oxygen management in hospitalised patients

BACKGROUND

Oxygen is commonly used in the acute care setting. However, used inappropriately, oxygen therapy can result in adverse consequences, including progressive respiratory failure and death.

AIM

To investigate the effectiveness of a targeted intervention to improve prescribing practice and therapeutic application of supplemental oxygen.

METHODS

Respiratory, Oncology and Surgery wards were targeted for the intervention. Nursing and junior medical staff from these wards undertook an education programme about safe use of oxygen. Cross-sectional data about oxygen prescribing, administration and monitoring were collected on inpatients in these wards at baseline, and at 3 and 6 months post-intervention, using a modified version of the British Thoracic Society Oxygen Audit Tool.

RESULTS

At baseline, there was a written prescription for oxygen in 56% of patients (n = 43) using oxygen and this increased to 75% (n = 44) at 3 months, and remained at 65% (n = 48) at 6 months. However, the increased prescription rates were not statistically significant when compared to baseline (χ² = 3.54, df = 1, P = 0.06 and χ² = 0.73, df = 1, P = 0.40, respectively). The observed increase in oxygen prescriptions was driven by the medical wards: Oncology ward at 3 months (χ² = 8.24, df = 1, P = 0.004); and Respiratory ward at 3 months (χ² = 3.31, df = 1, P = 0.069) and 6 months (χ² = 4.98, df = 1, P = 0.026).

CONCLUSION

The education programme intervention to improve oxygen prescription showed promise in the medical wards but did not impact outcomes in the surgical ward setting, where different strategies may be needed.

Anemia, nutrition, and ambulatory oxygen weaning in a cohort of oxygen-dependent premature infants

BACKGROUND

In Bogotá, Colombia, oxygen-dependent (OD) preterm infants are home discharged in Kangaroo Position, to a Kangaroo Mother Care Program (KMCP) with ambulatory oxygen, strict follow-up, and oxygen weaning protocols.

OBJECTIVES

(1) To describe growth, morbimortality, and oxygen monitoring up to 6 months in OD preterm infants. (2) To explore associations between oxygen weaning, perinatal history, Hb levels, transfusions, feeding patterns, and growth.

METHODS

A prospective cohort study. Descriptive and multivariate analysis.

RESULTS

Recruited patients were 407 with 33 weeks median gestational age (GA). Mothers presented infections >28%, pre-eclampsia in 22%, and 80% received antenatal corticosteroids. Upon KMCP admission, median GA, chronological age, and hospital stay were 36 weeks, 21 and 17 days, respectively; 56.8% of patients had neonatal sepsis and 67.8% were admitted to the neonatal intensive care unit. At oxygen weaning, patients had a median of 54 days with oxygen, median weight 3240 g and GA 41 weeks. Median follow-up oxygen saturation was 94% with 1/64-1/2 L/min of oxygen. One-year mortality was 0.2% and attrition 20%. At 6 months, all patients had appropriate growth and 67% were breastfeeding. Multiple regression analysis showed that higher GA, Hb levels, weight gain, and exclusive breastfeeding decreased oxygen requirement while invasive ventilation and transfusions had the opposite effect (R²  = .49).

CONCLUSIONS

In OD preterm infants, there is a close relationship between days of oxygen requirement and GA, mechanical ventilation, Hb levels at discharge, transfusions, exclusive breastfeeding, and weight gain. Strict monitoring with established protocols in an ambulatory KMCP allows adequate growth and safe oxygen weaning.

Acute Responses to Oxygen Delivery via High Flow Nasal Cannula in Patients with Severe Chronic Obstructive Pulmonary Disease-HFNC and Severe COPD

Differences in oxygen delivery methods to treat hypoxemia have the potential to worsen CO₂ retention in chronic obstructive lung disease (COPD). Oxygen administration using high flow nasal cannula (HFNC) has multiple physiological benefits in treating respiratory failure including reductions in PaCO₂ in a flow-dependent manner. We hypothesized that patients with COPD would develop worsening hypercapnia if oxygen fraction was increased without increasing flow rate. We evaluated the acute response to HFNC in subjects with severe COPD when flow remained constant and inspired oxygen was increased. In total, 11 subjects with severe COPD (FEV1 < 50%) on supplemental oxygen with baseline normocapnia (PaCO₂ < 45 mm Hg; n = 5) and hypercapnia (PaCO₂ ≥ 45 mm Hg; n = 6) were studied. Arterial blood gas responses were studied at three timepoints: Baseline, HFNC at a flow rate of 30 L/min at resting oxygen supplementation for 1 h, and FiO₂ 30% above baseline with the same flow rate for the next hour. The primary endpoint was the change in PaCO₂ from baseline. No significant changes in PaCO₂ were noted in response to HFNC applied at baseline FiO₂ in the normocapnic and hypercapnic group. At HFNC with FiO₂ 30% above baseline, the normocapnic group did not show a change in PaCO₂ (baseline: 38.9 ± 1.8 mm Hg; HFNC at higher FiO₂: 38.8 ± 3.1 mm Hg; p = 0.93), but the hypercapnic group demonstrated significant increase in PaCO₂ (baseline: 58.2 ± 9.3 mm Hg; HFNC at higher FiO₂: 63.3 ± 10.9 mm Hg; p = 0.025). We observed worsening hypercapnia in severe COPD patients and baseline hypercapnia who received increased oxygen fraction when flow remained constant. These data show the need for careful titration of oxygen therapy in COPD patients, particularly those with baseline hypercapnia when flow rate is unchanged.

A randomized controlled trial of oxygen therapy for patients who do not respond to upper airway surgery for obstructive sleep apnea

STUDY OBJECTIVES

We aimed to determine whether patients diagnosed with obstructive sleep apnea (OSA) who fail to respond to upper airway surgery may be successfully treated with supplemental oxygen and whether we could identify baseline physiologic endotypes (ie, collapsibility, loop gain, arousal threshold, and muscle compensation) that predict response to oxygen therapy.

METHODS

We conducted a single night, randomized double-blinded cross over trial in which patients with OSA who failed to respond to upper airway surgery were treated on separate nights with oxygen therapy (4 L/min) or placebo (medical air). Effect of oxygen/air on OSA on key polysomnography outcomes were assessed: apnea-hypopnea index (AHI), AHI without desaturation (ie, flow-based AHI), arousal index, and morning blood pressure. OSA endotypes were estimated from the polysomnography signals to determine whether baseline OSA physiology could be used to predict response to oxygen therapy.

RESULTS

There was a statistically significant reduction in AHI and flow-based AHI on oxygen vs placebo (flow-based AHI: 42.4 ± 21.5 vs 30.5 ± 17.1 events/h, P = .008). Arousal index was also reduced on oxygen vs placebo (41.1 ± 19.5 vs 33.0 ± 15.3 events/h, P = .006). There was no significant difference in morning blood pressure between oxygen and placebo. Although 7 of 20 individuals experienced a 50% reduction or greater in flow-based AHI on oxygen (responders), there was no difference in the baseline OSA endotypes (or clinical characteristics) between responders and nonresponders.

CONCLUSIONS

Our findings demonstrate that a proportion of patients who fail to respond to upper airway surgery for OSA respond acutely to treatment with supplemental oxygen.

CLINICAL TRIAL REGISTRATION

Registry: Australian New Zealand Clinical Trials Registry; Name: Oxygen therapy for treating patients with residual obstructive sleep apnea following upper airway surgery; URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=373566; Identifier: ACTRN12617001361392.

Respiratory Therapeutic Strategies in Children and Adolescents with COVID-19: A Critical Review

Evidence on the treatment strategies for the child population with critical conditions due to COVID-19 is scarce and lacks consensus. Thus, this study aimed to critically review non-pharmacological respiratory strategies for this population. Original studies were searched in six databases considering predefined inclusion criteria. Other studies and recommendations were also included after a manual search. Oxygen therapy, invasive (IMV) and non-invasive (NIV) ventilation were the most frequently addressed interventions. In general, the original studies have cited these strategies, but detailed information on the parameters used was not provided. The recommendations provided more detailed data, mainly based on experiences with other acute respiratory syndromes in childhood. In the context of oxygen therapy, the nasal catheter was the most recommended strategy for hypoxemia, followed by the high-flow nasal cannula (HFNC). However, the risks of contamination due to the dispersion of aerosols in the case of the HFNC were pointed out. Lung protective IMV with the use of bacteriological or viral filters was recommended in most documents, and there was great variation in PEEP titration. Alveolar recruitment maneuvers were mentioned in a few recommendations. NIV was not consensual among studies, and when selected, several precautions must be taken to avoid contamination. Airway suctioning with a closed-circuit was recommended to reduce aerosol spread. Information on prone positioning and physiotherapy was even more scarce. In conclusion, oxygen therapy seems to be essential in the treatment of hypoxemia. If necessary, IMV should not be delayed, and protective strategies are encouraged for adequate pulmonary ventilation. Information about techniques that are adjuvant to ventilatory support is superficial and requires further investigation.

Failure of High Flow Nasal Cannula and Subsequent Intubation Is Associated With Increased Mortality as Compared to Failure of Non-Invasive Ventilation and Mechanical Ventilation Alone: A Real-World Retrospective Analysis

BACKGROUND

Despite the increasing use of high flow nasal cannula oxygenation systems (HFNC) in clinical practice, little is known about its role in all cause respiratory failure as compared to traditional non-invasive ventilation (BiPAP). Furthermore, the effect of HFNC on mortality is unknown.

METHODS

We conducted a retrospective analysis of 49,853 patients with respiratory failure treated with non-invasive respiratory support (HFNC or BiPAP) and/or invasive mechanical ventilation (IMV) between 2017 and 2018.

RESULTS

Patients initially treated with HFNC who underwent subsequent intubation and IMV had a higher mortality rate as compared to patients who were initially treated with BiPAP and underwent subsequent intubation and IMV (34.8% vs 26.3%, p < 0.0001, OR 1.49, 95% CI 1.26,1.76). Patients first treated with HFNC who underwent subsequent intubation and IMV had a significantly increased mortality compared to patients who underwent immediate intubation and IMV (34.8% vs. 21.5%, p ≤ 0.0001, OR 1.94, 95% CI 1.67, 2.27). Stratified based on ICD-10 diagnosis, patients with a diagnosis of COPD exacerbation or heart failure treated with HFNC and subsequent intubation and IMV had higher mortality as compared to those treated with immediate IMV alone. This trend did not hold true for patients with a diagnosis of pneumonia.

CONCLUSION

In a real-world retrospective analysis, use of HFNC was associated with increased mortality as compared to BiPAP and IMV alone. Further study is needed to confirm these associations.

Acute oxygen therapy: a cross-sectional study of prescribing practices at an English hospital immediately before COVID-19 pandemic

BACKGROUND

Approximately 14% of UK hospital in-patients receive supplemental oxygen therapy, only 57% have valid prescriptions. Oxygen must be optimally prescribed to ensure maximal therapeutic response whilst minimizing adverse outcomes (including fatality). This study investigates prescription compliance.

METHODS

All adults admitted to medical wards (18 February to 3 March 2020) were included. Analyses present proportions, descriptive statistics, and hypothesis testing. Ethical approval was unnecessary for this audit.

RESULTS

Of the 636 patients admitted, 66 (10%) were receiving oxygen therapy. Ages ranged from 34 to 100 years with 36 (54.5%) males and 30 (45.5%) females. The prescription was not documented in the oxygen section of the drug chart (n = 37, 56.1%, p = 0.389), nor did it have the physicians signature (n = 40, 60.6%, p = 0.110) nor date (n = 46, 69.7%, p = 0.002). Thirteen chronic obstructive pulmonary disease (COPD) patients (19.7%) were at risk of hypercapnic failure (p = 1.582x10^-6). Target oxygen saturation (SpO2) range had been documented for 30 (45.5%) patients. A target SpO2 range of 88-92% was documented for 9 patients (13.6%), a 94-98% range documented for 11 patients (16.7%). All patients had an invalid prescription.

CONCLUSION

We present real-world practice in naturalistic settings, immediately before pandemic-lockdown. Enhanced compliance is advocated to reduce risks of harm and mortality.

Efficacy of high-flow nasal prong therapy in trauma patients with rib fractures and high-risk features for respiratory deterioration: a randomized controlled trial

BACKGROUND

Patients with rib fractures require analgesia, oxygen supplementation and physiotherapy. This combination has been shown to reduce morbidity and mortality due to rib fractures. There has been movement towards the use of high-flow nasal prong (HFNP) oxygen. However there are no studies demonstrating the effectiveness of HFNP in this population. The aim of this study was to compare HFNP to venturi mask (VM) in rib fracture patients.

METHODS

Randomized controlled trial. Patient population included patients with rib fractures and high-risk features (three or more rib fractures, flail segment, bilateral rib fractures, smoker or chronic obstructive pulmonary disease). Exclusion criteria included initial mechanical ventilation and contraindications to HFNP. Patients were randomized to HFNP or VM. Primary outcome was deterioration requiring mechanical invasive/non-invasive ventilation, or unplanned admission to intensive care unit. Secondary outcomes included mortality, length of stay, high dependency length of stay, comfort levels, breathing exertion levels (as measured by Borg Scale), oxygen saturation, respiratory rate, heart rate, chest X-ray and arterial blood gas parameters.

RESULTS

220 patients (average age 60 years and average of four rib fractures each) were randomized to HFNP (n=113) and VM (n=107). There was no statistically significant difference in the primary outcome comparing HFNP and VM (6.2% vs. 6.5%, p=1.0). There were also no statistically significant differences in the secondary outcomes except for PaCO₂ (43.6 vs. 45.5, p=0.039).

CONCLUSION

HFNP oxygen supplementation does not appear to be more effective than VM oxygen supplementation in patients with rib fractures.

RECOVERY- Respiratory Support: Respiratory Strategies for patients with suspected or proven COVID-19 respiratory failure; Continuous Positive Airway Pressure, High-flow Nasal Oxygen, and standard care: A structured summary of a study protocol for a randomised controlled trial

Objective

The trial objective is to determine if Continuous Positive Airway Pressure (CPAP) or High-Flow Nasal Oxygen (HFNO) is clinically effective compared to standard oxygen therapy in patients with confirmed or suspected COVID-19.

Trial design

Adaptive (group-sequential), parallel group, pragmatic, superiority randomised controlled, open-label, multi-centre, effectiveness trial.

Participants

The trial is being conducted across approximately 60 hospitals across England, Wales, Scotland, and Northern Ireland. Inpatients at participating hospitals are eligible to participate if they have respiratory failure with suspected or proven COVID-19, and meet all of the inclusion criteria and none of the exclusion criteria.

Inclusion criteria: 1) Adults ≥ 18 years; 2) Admitted to hospital with suspected or proven COVID-19; 3) Receiving oxygen with fraction of inspired oxygen (FiO₂) ≥0.4 and peripheral oxygen saturation (SpO₂) ≤94%; and 4) Plan for escalation to tracheal intubation if needed.

Exclusion criteria: 1) Planned tracheal intubation and mechanical ventilation imminent within 1 hour; 2) Known or clinically apparent pregnancy; 3) Any absolute contraindication to CPAP or HFNO; 4) Decision not to intubate due to ceiling of treatment or withdrawal of treatment anticipated; and 5) Equipment for both CPAP and HFNO not available.

Intervention and comparator

Intervention one: Continuous positive airway pressure delivered by any device. Set-up and therapy titration is not protocolised and is delivered in accordance with clinical discretion.

Intervention two: High-flow nasal oxygen delivered by any device. Set-up and therapy titration is not protocolised and is delivered in accordance with clinical discretion.

Comparator group: Standard care- oxygen delivered by face mask or nasal cannula (excluding the use of continuous positive airway pressure or high-flow nasal oxygen). Set-up and therapy titration is not protocolised and is delivered in accordance with clinical discretion.

Intervention delivery continues up to the point of death, tracheal intubation, or clinical determination that there is no ongoing need (palliation or improvement).

Main outcomes

The primary outcome is a composite outcome comprising tracheal intubation or mortality within 30 days following randomisation.

Secondary outcomes include tracheal intubation rate, time to tracheal intubation, duration of invasive ventilation, mortality rate, time to mortality, length of hospital stay, and length of critical care stay.

Randomisation

Participants are randomised in a 1:1:1 ratio to receive either continuous positive airway pressure, high-flow nasal oxygen or standard care. Due to the challenging environment of study delivery, a specific intervention may not always be available at the hospital site. The study uses two integrated randomisation systems to allow, where required, the site to randomise between all three interventions, between CPAP and standard care, and between HFNO and standard care. System integration ensures maintenance of balance between interventions.

Randomisation is performed using a telephone-based interactive voice response system to maintain allocation concealment. The randomisation sequence was computer-generated using the minimisation method. Participant randomisation is stratified by site, gender (M/F), and age (<50, >=50 years).

Blinding (masking)

The nature of the trial interventions precludes blinding of the researcher, patient and clinical team. Primary and secondary outcomes are all objective outcomes, thereby minimising the risk of detection bias.

Numbers to be randomised (sample size)

4002 participants (1334 to be randomized to each of the three study arms)

Trial Status

Current protocol: Version 4.0, 29^th May 2020. Recruitment began on April 6, 2020 and is anticipated to be complete by April 5, 2021.

The trial has been awarded Urgent Public Health status by the National Institute of Health Research on 13^th April 2020.

Trial registration

ISRCTN, ISRCTN16912075. Registered 6^th April 2020, http://www.isrctn.com/ISRCTN16912075

Full protocol

The full protocol (version 4.0, 29^th May 2020) is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2).

The handling oxygenation targets in the intensive care unit (HOT-ICU) trial: Detailed statistical analysis plan

BACKGROUND

No solid evidence exists on optimal oxygenation targets in intensive care patients. The handling oxygenation targets in the intensive care unit (HOT-ICU) trial assesses the effects of a targeted arterial oxygen tension of 8 vs 12 kPa on 90-day mortality in acutely admitted adult patients with hypoxaemic respiratory failure. This article describes the detailed statistical analysis plan for the predefined outcomes and supplementary analyses in the HOT-ICU trial.

METHODS

The trial will include 2928 patients to be able to detect or reject a true 20% relative risk reduction in the primary outcome of 90-day all-cause mortality with an α of 5% and a β of 10%. Analyses of the primary and secondary outcomes will be conducted according to the intention-to-treat principle and adjusted for stratification variables. The primary outcome and dichotomous secondary outcomes will be analysed using a generalised linear model with a log-link and binomial error distribution. For the primary outcome, a 95% confidence interval (CI) not including 1.00 for the risk ratio will be considered statistically significant. Continuous secondary outcomes will be analysed using a generalised linear model or nonparametric test. CIs adjusted for the multiple secondary outcomes not including the null effect will be considered statistically significant. One planned interim analysis has been conducted.

CONCLUSIONS

The HOT-ICU trial and the pre-planned statistical analyses are designed to minimise bias and produce high quality data on the effects of a lower vs a higher oxygenation target throughout ICU admission in acutely admitted adult patients with hypoxaemic respiratory failure.

REGISTRATION

ClinicalTrials.gov identifier: NCT03174002, date of registration: June 2, 2017. European clinical trials database, EudraCT number 2017-000632-34.

Factors Associated With Failure of High-Flow Nasal Cannula

BACKGROUND

The use of high-flow nasal cannula (HFNC) is rapidly increasing without clear indications, creating the potential for overuse or misuse and the accompanying risk of adverse events. The purpose of this study was to determine the factors associated with HFNC failure by examining the current clinical practice of HFNC.

METHODS

From July 1, 2017, to June 30, 2018, in 5 university-affiliated hospitals in the Republic of Korea, a total of 1,161 admitted adult subjects who had HFNC administered were retrospectively enrolled and their medical records were reviewed.

RESULTS

Pulmonary diseases including pneumonia (n = 757, 65.2%) were the most common reason for use of HFNC. Subjects with do-not-resuscitate (DNR) or do-not-intubate (DNI) orders comprised 33.8% of the study population (n = 392); 563 subjects (48.5%) were escalated directly to HFNC from low-flow devices without applying reservoir or other high-flow devices. In the non-DNR/DNI subjects, arterial blood gas was not monitored in 15.2% and 14.8% of subjects before and after HFNC application, respectively, and it was not monitored in 28.0% just before HFNC weaning. The HFNC failure rate was 27.0% in non-DNR/DNI subjects, and the HFNC failure was significantly associated with the decision by residents to apply HFNC (odds ratio [OR] 2.03, 95% CI 1.29-3.18, P = .002), high breathing frequency (OR 1.07, 95% CI 1.04-1.10, P < .001) ≤ 6 h before HFNC application, low [Formula: see text] (OR 0.92, 95% CI 0.89-0.95, P < .001) ≤ 6 h before HFNC application, low [Formula: see text] (OR 0.95, 95% CI 0.93-0.98, P < .001) ≤ 6 h before HFNC application, and the ratio of [Formula: see text]/[Formula: see text] to breathing frequency (ROX index) ≤ 6 h after HFNC application (OR 0.88, 95% CI 0.84-0.92, P < .001).

CONCLUSIONS

HFNC was practiced without applying reservoir or other high-flow devices before application and without appropriate arterial blood gas monitoring during HFNC therapy. HFNC failure was significantly associated with the decision by the resident to use HFNC, breathing frequency, [Formula: see text], and [Formula: see text] ≤ 6 h before HFNC application, and with the ROX index ≤ 6 h after HFNC application.

Temporal convolutional networks allow early prediction of events in critical care

OBJECTIVE

Clinical interventions and death in the intensive care unit (ICU) depend on complex patterns in patients' longitudinal data. We aim to anticipate these events earlier and more consistently so that staff can consider preemptive action.

MATERIALS AND METHODS

We use a temporal convolutional network to encode longitudinal data and a feedforward neural network to encode demographic data from 4713 ICU admissions in 2014-2018. For each hour of each admission, we predict events in the subsequent 1-6 hours. We compare performance with other models including a recurrent neural network.

RESULTS

Our model performed similarly to the recurrent neural network for some events and outperformed it for others. This performance increase was more evident in a sensitivity analysis where the prediction timeframe was varied. Average positive predictive value (95% CI) was 0.786 (0.781-0.790) and 0.738 (0.732-0.743) for up- and down-titrating FiO2, 0.574 (0.519-0.625) for extubation, 0.139 (0.117-0.162) for intubation, 0.533 (0.492-0.572) for starting noradrenaline, 0.441 (0.433-0.448) for fluid challenge, and 0.315 (0.282-0.352) for death.

DISCUSSION

Events were better predicted where their important determinants were captured in structured electronic health data, and where they occurred in homogeneous circumstances. We produce partial dependence plots that show our model learns clinically-plausible associations between its inputs and predictions.

CONCLUSION

Temporal convolutional networks improve prediction of clinical events when used to represent longitudinal ICU data.

High-Flow Nasal Cannula May Not Reduce the Re-Intubation Rate Compared With a Large-Volume Nebulization-Based Humidifier

BACKGROUND

High-flow nasal cannula (HFNC) therapy may reduce the re-intubation rate compared with conventional oxygen therapy. However, HFNC has not been sufficiently compared with conventional oxygen therapy with a heated humidifier, even though heated humidification is beneficial for facilitating airway clearance.

METHODS

This study was a single-center, open-label, randomized controlled trial. We randomized subjects with respiratory failure after extubation to either HFNC group or to a large-volume humidified nebulization-based nebulizer. The primary end point was the re-intubation rate within 7 d after extubation.

RESULTS

We could not recruit enough subjects for the sample size we designed, therefore, we analyzed 69 subjects (HFNC group, 30 subjects; nebulizer group, 39 subjects). The re-intubation rate within 7 d was not significantly different between the HFNC and nebulizer groups (5/30 subjects [17%] and 6/39 subjects [15%], respectively; P > .99). [Formula: see text]/set [Formula: see text] at 24 h after extubation was also not significantly different between the respective groups (264 ± 105 mm Hg in the HFNC group vs 224 ± 53 mm Hg in the nebulizer group; P = .07).

CONCLUSIONS

Compared with a large-volume nebulization-based humidifier, HFNC may not reduce the re-intubation rate within 7 d. However, because of insufficient statistical power, further studies are needed to reach a conclusion.