Importance
The optimal first-line mode of noninvasive respiratory support following extubation of critically ill children is not known.


Objective
To evaluate the noninferiority of high-flow nasal cannula (HFNC) therapy as the first-line mode of noninvasive respiratory support following extubation, compared with continuous positive airway pressure (CPAP), on time to liberation from respiratory support.


Design, Setting, and Participants
This was a pragmatic, multicenter, randomized, noninferiority trial conducted at 22 pediatric intensive care units in the United Kingdom. Six hundred children aged 0 to 15 years clinically assessed to require noninvasive respiratory support within 72 hours of extubation were recruited between August 8, 2019, and May 18, 2020, with last follow-up completed on November 22, 2020.


Interventions
Patients were randomized 1:1 to start either HFNC at a flow rate based on patient weight (n = 299) or CPAP of 7 to 8 cm H2O (n = 301).


Main Outcomes and Measures
The primary outcome was time from randomization to liberation from respiratory support, defined as the start of a 48-hour period during which the child was free from all forms of respiratory support (invasive or noninvasive), assessed against a noninferiority margin of an adjusted hazard ratio (HR) of 0.75. There were 6 secondary outcomes, including mortality at day 180 and reintubation within 48 hours.


Results
Of the 600 children who were randomized, 553 children (HFNC, 281; CPAP, 272) were included in the primary analysis (median age, 3 months; 241 girls [44%]). HFNC failed to meet noninferiority, with a median time to liberation of 50.5 hours (95% CI, 43.0-67.9) vs 42.9 hours (95% CI, 30.5-48.2) for CPAP (adjusted HR, 0.83; 1-sided 97.5% CI, 0.70-∞). Similar results were seen across prespecified subgroups. Of the 6 prespecified secondary outcomes, 5 showed no significant difference, including the rate of reintubation within 48 hours (13.3% for HFNC vs 11.5 % for CPAP). Mortality at day 180 was significantly higher for HFNC (5.6% vs 2.4% for CPAP; adjusted odds ratio, 3.07 [95% CI, 1.1-8.8]). The most common adverse events were abdominal distension (HFNC: 8/281 [2.8%] vs CPAP: 7/272 [2.6%]) and nasal/facial trauma (HFNC: 14/281 [5.0%] vs CPAP: 15/272 [5.5%]).


Conclusions and Relevance
Among critically ill children requiring noninvasive respiratory support following extubation, HFNC compared with CPAP following extubation failed to meet the criterion for noninferiority for time to liberation from respiratory support.


Trial Registration
isrctn.org Identifier: ISRCTN60048867.

/pdf/effect-of-high-flow-nasal-cannula-therapy-vs-continuous-17fq5iqh.pdf

Effect of High-Flow Nasal Cannula Therapy vs Continuous Positive Airway Pressure Following Extubation on Liberation From Respiratory Support in Critically Ill Children: A Randomized Clinical Trial.

Pragmatic use of the anti-fibrotic medications pirfenidone and nintedanib for idiopathic pulmonary fibrosis (IPF) in the United States (US) has not been studied and may be different from international settings due to structural differences between health care systems. This study examined the relationship between patient- and site-level characteristics and anti-fibrotic (a) use and (b) selection. Data from the Pulmonary Fibrosis Foundation Patient Registry was used to perform univariable and multivariable regressions with generalized linear mixed models. A random effects model examined registry site variation. 703 of 1218 (57.7%) patients were taking a single anti-fibrotic of which 312 (44.4%) were taking nintedanib and 391 (55.6%) were taking pirfenidone. Up to 25% of patients using an anti-fibrotic may have been excluded from clinical trial participation due to having too severe disease as measured by diffusion limitation for carbon monoxide. Age (OR = 0.974, p = 0.0086) and diffusion capacity of the lungs for carbon monoxide (per 10% increase in percent-predicted; OR = 0.896, p = 0.0007) was negatively associated with anti-fibrotic use while time (in log of days) since diagnosis (OR = 1.138, p < 0.0001), recent patient clinical trial participation (OR = 1.569, p = 0.0433) and oxygen use (OR = 1.604, p = 0.0027) was positively associated with anti-fibrotic use. Time (log of days) since diagnosis (OR = 1.075, p = 0.0477), history of coronary artery disease (OR = 1.796, p = 0.0030), presence of pulmonary hypertension (OR = 2.139, p = 0.0376), patient clinical trial participation in the prior 12 months (OR = 2.485, p = 0.0002), diffusion capacity of the lungs for carbon monoxide (per 10% increase in percent-predicted; OR = 1.138, p = 0.0184), anticoagulant use (OR = 2.507, p = 0.0028), and enrollment at a registry site in the Midwest region (OR = 1.600, p = 0.0446) were associated with pirfenidone use. Anti-fibrotic use varied by registry site. Rates of discontinuation were modest and nearly identical for the two medications with side effects being the most common reason given for discontinuation. Twenty-three percent (23%, 274) of persons with IPF were using or had recently used an immunomodulatory agent. This analysis provides a detailed characterization of IPF treatment patterns in the US; many users of anti-fibrotic medications may not have qualified for inclusion in clinical trials. More research is needed to understand variations in medical decision-making for use and selection of anti-fibrotic medication.

/pdf/patient-and-site-characteristics-associated-with-pirfenidone-l6lwmjrfwx.pdf

Patient and site characteristics associated with pirfenidone and nintedanib use in the United States; an analysis of idiopathic pulmonary fibrosis patients enrolled in the Pulmonary Fibrosis Foundation Patient Registry

ARDS has a high mortality in the acute setting, with long-term disability among disease survivors. In 1967, David Ashbaugh and colleagues first described the clinical features of ARDS, which were notably similar to the infantile respiratory distress syndrome. Half a century later, ARDS remains underrecognized and is associated with high mortality rates. Valuable insights from observational studies fail to demonstrate a mortality benefit in randomized controlled trials (RCTs). In the absence of a pharmacologic cure, supportive ventilator strategies limit rather than treat the ongoing lung injury. Interestingly, ARDS has higher mortality rates in observational studies compared to RCTs. Comparing mortality rates between ARDS studies and trials is problematic, partly due to varying time-points at which mortality is reported. Discerning the true mortality attributable to ARDS is also difficult. The diagnostic criteria for ARDS are mainly clinical and lack the objectivity of a laboratory test or biomarker. Nonetheless, these factors are common to both studies and trials, and fail to explain the higher mortality rate of ARDS observational studies. Disease heterogeneity and complex patient characteristics can also confound mortality estimation in ARDS. We therefore examined patient and trial factors that could influence mortality outcomes in ARDS observational studies and RCTs. Unlike RCTs, observational studies include ARDS subjects with severe comorbidities and those requesting limited care. Less stringent selection criteria could thereby contribute to high mortality rates in ARDS observational studies. In contrast, exclusion criteria in RCTs meticulously scrutinize patient characteristics, confining the type and number of eligible subjects. As a result, the task of identifying, consenting, and randomizing eligible patients within the enrollment window is challenging, further decreasing the number of subjects enrolled. Moreover, ARDS RCTs strictly adhere to lung-protective strategies, while ARDS observational studies continually demonstrate variable compliance. This review highlights the impact of patient- and trial-related factors on influencing mortality rates in ARDS observational studies and RCTs.

http://rc.rcjournal.com/content/respcare/63/8/1060.full.pdf

Influence of Clinical Factors and Exclusion Criteria on Mortality in ARDS Observational Studies and Randomized Controlled Trials.

Importance
The optimal first-line mode of noninvasive respiratory support for acutely ill children is not known.


Objective
To evaluate the noninferiority of high-flow nasal cannula therapy (HFNC) as the first-line mode of noninvasive respiratory support for acute illness, compared with continuous positive airway pressure (CPAP), for time to liberation from all forms of respiratory support.


Design, Setting, and Participants
Pragmatic, multicenter, randomized noninferiority clinical trial conducted in 24 pediatric critical care units in the United Kingdom among 600 acutely ill children aged 0 to 15 years who were clinically assessed to require noninvasive respiratory support, recruited between August 2019 and November 2021, with last follow-up completed in March 2022.


Interventions
Patients were randomized 1:1 to commence either HFNC at a flow rate based on patient weight (n = 301) or CPAP of 7 to 8 cm H2O (n = 299).


Main Outcomes and Measures
The primary outcome was time from randomization to liberation from respiratory support, defined as the start of a 48-hour period during which a participant was free from all forms of respiratory support (invasive or noninvasive), assessed against a noninferiority margin of an adjusted hazard ratio of 0.75. Seven secondary outcomes were assessed, including mortality at critical care unit discharge, intubation within 48 hours, and use of sedation.


Results
Of the 600 randomized children, consent was not obtained for 5 (HFNC: 1; CPAP: 4) and respiratory support was not started in 22 (HFNC: 5; CPAP: 17); 573 children (HFNC: 295; CPAP: 278) were included in the primary analysis (median age, 9 months; 226 girls [39%]). The median time to liberation in the HFNC group was 52.9 hours (95% CI, 46.0-60.9 hours) vs 47.9 hours (95% CI, 40.5-55.7 hours) in the CPAP group (absolute difference, 5.0 hours [95% CI -10.1 to 17.4 hours]; adjusted hazard ratio 1.03 [1-sided 97.5% CI, 0.86-∞]). This met the criterion for noninferiority. Of the 7 prespecified secondary outcomes, 3 were significantly lower in the HFNC group: use of sedation (27.7% vs 37%; adjusted odds ratio, 0.59 [95% CI, 0.39-0.88]); mean duration of critical care stay (5 days vs 7.4 days; adjusted mean difference, -3 days [95% CI, -5.1 to -1 days]); and mean duration of acute hospital stay (13.8 days vs 19.5 days; adjusted mean difference, -7.6 days [95% CI, -13.2 to -1.9 days]). The most common adverse event was nasal trauma (HFNC: 6/295 [2.0%]; CPAP: 18/278 [6.5%]).


Conclusions and Relevance
Among acutely ill children clinically assessed to require noninvasive respiratory support in a pediatric critical care unit, HFNC compared with CPAP met the criterion for noninferiority for time to liberation from respiratory support.


Trial Registration
ISRCTN.org Identifier: ISRCTN60048867.

/pdf/effect-of-high-flow-nasal-cannula-therapy-vs-continuous-1a6vo0p1.pdf

Effect of High-Flow Nasal Cannula Therapy vs Continuous Positive Airway Pressure Therapy on Liberation From Respiratory Support in Acutely Ill Children Admitted to Pediatric Critical Care Units: A Randomized Clinical Trial.

Obesity is associated with the development of acute respiratory distress syndrome (ARDS) in at-risk patients. Low plasma levels of adiponectin, a circulating hormone-like molecule, have been implicated as a possible mechanism for this association. The objective of this study was to determine the association of plasma adiponectin level at ICU admission with ARDS and 30-day mortality in patients with severe sepsis and septic shock. This is a prospective cohort study of patients admitted to the medical ICU at the Hospital of the University of Pennsylvania. Plasma adiponectin was measured at the time of ICU admission. ARDS was defined by Berlin criteria. Multivariable logistic regression was used to determine the association of plasma adiponectin with the development of ARDS and mortality at 30 days. The study included 164 patients. The incidence of ARDS within 5 days of admission was 45 %. The median initial plasma adiponectin level was 7.62 mcg/ml (IQR: 3.87, 14.90) in those without ARDS compared to 8.93 mcg/ml (IQR: 4.60, 18.85) in those developing ARDS. The adjusted odds ratio for ARDS associated with each 5 mcg increase in adiponectin was 1.12 (95 % CI 1.01, 1.25), p-value 0.025). A total of 82 patients (51 %) of the cohort died within 30 days of ICU admission. There was a statistically significant association between adiponectin and mortality in the unadjusted model (OR 1.11, 95 % CI 1.00, 1.23, p-value 0.04) that was no longer significant after adjusting for potential confounders. In this study, low levels of adiponectin were not associated with an increased risk of ARDS in patients with severe sepsis and septic shock. This argues against low levels of adiponectin as a mechanism explaining the association of obesity with ARDS. At present, it is unclear whether circulating adiponectin is involved in the pathogenesis of ARDS or simply represents an epiphenomenon of other unknown functions of adipose tissue or metabolic alterations in sepsis.

/pdf/low-plasma-levels-of-adiponectin-do-not-explain-acute-3imkl9nae3.pdf

Low Plasma Levels of Adiponectin Do Not Explain Acute Respiratory Distress Syndrome Risk: a Prospective Cohort Study of Patients with Severe Sepsis

Rationale: Patients eligible for randomized controlled trials may not be enrolled for various reasons. Nonenrollment may affect study generalizability and lengthen the time required for trial completion.Objectives: To describe characteristics and outcomes of eligible nonenrolled (ENE) patients in a multicenter trial of mechanical ventilation strategies.Methods: Within the OSCILLATE trial of high-frequency oscillation (HFO) versus conventional ventilation (CV) in adults with adult respiratory distress syndrome, and with approval from research ethics boards, we collected a minimal dataset on patients who satisfied eligibility criteria but were not enrolled. We categorized ENE patients as ENE-HFO and ENE-CV based on receipt of HFO at any time. We used multivariable logistic regression to assess the association between ENE status and mortality.Measurements and Main Results: A total of 548 patients were randomized, and 546 were ENE. The most common reasons for ENE were no consent (42%), physician refusal (24%)...

/pdf/characteristics-and-outcomes-of-eligible-nonenrolled-2kng5xcepd.pdf

Russell Graham

Papers

Characteristics and Outcomes of Eligible Nonenrolled Patients in a Mechanical Ventilation Trial of Acute Respiratory Distress Syndrome