Pediatric acute respiratory distress syndrome: definition, incidence, and epidemiology: proceedings from the Pediatric Acute Lung Injury Consensus Conference

Characterization of organ dysfunction and mortality in pediatric patients with trauma with acute traumatic coagulopathy

Background

Traumatic injuries are a leading cause of mortality and morbidity in pediatric patients and abnormalities in hemostasis play an important role in these poor outcomes. One such abnormality, acute traumatic coagulopathy (ATC), is a near immediate endogenous response to injury and has recently been described in the pediatric population. This study aims to evaluate the epidemiology of pediatric ATC, specifically its association with organ dysfunction.

Methods

All patients with trauma presenting to the University of California, Benioff Children's Hospital Oakland between 2006 and 2015 with coagulation testing drawn at presentation were included. Patients were excluded if they (1) were >18 years of age, (2) were admitted with a non-mechanical mechanism of injury, (3) were on anticoagulation medications, or (4) had coagulation testing >4 hours after injury. ATC was defined as an international normalized ratio (INR) ≥1.3. The primary outcome was new or progressive multiple organ dysfunction syndrome (MODS) and secondary outcomes included in-hospital mortality and other morbidities.

Results

Of the 7382 patients that presented in the 10-year study period, 545 patients met criteria for analysis and 88 patients (16%) presented with ATC. Patients with ATC were more likely to develop MODS than those without ATC (68.4% vs 7.7%, p<0.001) and had higher in-hospital mortality (26.1% vs 0.4%, p<0.001) than those without ATC. Along with arterial hypotension and an Injury Severity Score ≥30, ATC was independent predictor of MODS and in-hospital mortality. An isolated elevated INR was associated with MODS and in-hospital mortality while an isolated elevated partial thromboplastin time was not.

Conclusions

Pediatric ATC was associated with organ dysfunction, mortality, and other morbidities. ATC along with arterial hypotension and high injury severity were independent predictors of organ dysfunction and mortality. Pediatric ATC may be biologically distinct from adult ATC and further studies are needed.

Level of evidence

IV, epidemiologic.

Recommendations on the clinical management of the COVID-19 infection by the «new coronavirus» SARS-CoV2. Spanish Paediatric Association working group

On 31 December 2019, the Wuhan Municipal Committee of Health and Healthcare (Hubei Province, China) reported that there were 27 cases of pneumonia of unknown origin with symptoms starting on the 8 December. There were 7 serious cases with common exposure in market with shellfish, fish, and live animals, in the city of Wuhan. On 7 January 2020, the Chinese authorities identified that the agent causing the outbreak was a new type of virus of the Coronaviridae family, temporarily called «new coronavirus», 2019-nCoV. On January 30th, 2020, the World Health Organisation (WHO) declared the outbreak an International Emergency. On 11 February 2020 the WHO assigned it the name of SARS-CoV2 and COVID-19 (SARS-CoV2 and COVID-19). The Ministry of Health summoned the Specialties Societies to prepare a clinical protocol for the management of COVID-19. The Spanish Paediatric Association appointed a Working Group of the Societies of Paediatric Infectious Diseases and Paediatric Intensive Care to prepare the present recommendations with the evidence available at the time of preparing them.

[Phagocytosis of alveolar macrophages is suppressed in a mouse model of lipopolysaccharide-induced acute lung injury]

OBJECTIVE

To investigate the changes in phagocytic function of alveolar macrophages (AMs) in mice with lipopolysaccharide (LPS)-induced acute lung injury (ALI) and explore the possible mechanism.

METHODS

Kunming mice were randomly divided into normal control group and ALI (induced by LPS instillation in the airway) model group. AMs were obtained from bronchoalveolar lavage fluid in both groups, and phagocytosis of the AMs was observed using flow cytometry and fluorescence microscopy. Western blotting and ELISA were used to detect the expression and secretion of IL-33 in the lung tissue of the mice. We also detected the secretion of IL-33 by an alveolar epithelial cell line MLE-12 in response to stimulation with different concentrations of LPS. The AMs from the normal control mice were treated with different concentrations of LPS and IL-33, and the changes in the phagocytic activity of the cells were observed.

RESULTS

Compared with those in normal control group, the percentage of AMs phagocytosing fluorescent microspheres was significantly decreased, and the expression of IL-33 in lung tissue and IL-33 level in the bronchoalveolar lavage fluid were significantly increased in ALI mice (P < 0.01). LPS (100-1000 ng/mL) obviously promoted the secretion of IL-33 in cultured MLE-12 cells (P < 0.01). Both LPS (10-500 ng/mL) and IL-33 (100 ng/mL) significantly inhibited the phagocytic activity of the AMs from normal control mice (P < 0.01).

CONCLUSIONS

The phagocytic activity of AMs is weakened in ALI mice possibly due to direct LPS stimulation and the inhibitory effect of the alarmin IL-33 produced by LPS-stimulated alveolar epithelial cells.

[Recommendations on the clinical management of the COVID-19 infection by the «new coronavirus» SARS-CoV2. Spanish Paediatric Association working group]

On 31 December 2019, the Wuhan Municipal Committee of Health and Healthcare (Hubei Province, China) reported that there were 27 cases of pneumonia of unknown origin with symptoms starting on the 8 December. There were 7 serious cases with common exposure in market with shellfish, fish, and live animals, in the city of Wuhan. On 7 January 2020, the Chinese authorities identified that the agent causing the outbreak was a new type of virus of the Coronaviridae family, temporarily called «new coronavirus», 2019-nCoV. On January 30th, 2020, the World Health Organisation (WHO) declared the outbreak an International Emergency. On 11 February 2020 the WHO assigned it the name of SARS-CoV2 and COVID-19 (SARS-CoV2 and COVID-19). The Ministry of Health summoned the Specialties Societies to prepare a clinical protocol for the management of COVID-19. The Spanish Paediatric Association appointed a Working Group of the Societies of Paediatric Infectious Diseases and Paediatric Intensive Care to prepare the present recommendations with the evidence available at the time of preparing them.

[Recommendations on the clinical management of the COVID-19 infection by the «new coronavirus» SARS-CoV2. Spanish Paediatric Association working group]

On 31 December 2019, the Wuhan Municipal Committee of Health and Healthcare (Hubei Province, China) reported that there were 27 cases of pneumonia of unknown origin with symptoms starting on the 8 December. There were 7 serious cases with common exposure in market with shellfish, fish, and live animals, in the city of Wuhan. On 7 January 2020, the Chinese authorities identified that the agent causing the outbreak was a new type of virus of the Coronaviridae family, temporarily called «new coronavirus», 2019-nCoV. On January 30th, 2020, the World Health Organisation (WHO) declared the outbreak an International Emergency. On 11 February 2020 the WHO assigned it the name of SARS-CoV2 and COVID-19 (SARS-CoV2 and COVID-19). The Ministry of Health summoned the Specialties Societies to prepare a clinical protocol for the management of COVID-19. The Spanish Paediatric Association appointed a Working Group of the Societies of Paediatric Infectious Diseases and Paediatric Intensive Care to prepare the present recommendations with the evidence available at the time of preparing them.

Outcomes of Severe PARDS on High-Frequency Oscillatory Ventilation - A Single Centre Experience

OBJECTIVE

To describe experience with high-frequency oscillatory ventilation (HFOV) in children with acute respiratory distress syndrome (ARDS) transitioned from conventional mechanical ventilation (CMV) due to refractory hypoxemia and to assess factors associated with survival and also compare outcomes of patients who were managed with early HFOV (within 24 h of intubation) vs. late HFOV.

METHODS

This retrospective, observational study was conducted in a tertiary care hospital's pediatric intensive care unit. Thirty-four children with pediatric acute respiratory distress syndrome (PARDS) managed with HFOV were included.

RESULTS

Of 34 children with PARDS managed with HFOV after failure of conventional ventilation to improve oxygenation, 8 survived. Improvement in the Oxygenation Index (OI) at 48 h of initiation of HFOV along with percent increase in PaO₂/FiO₂ (P/F ratio) at 24 h of HFOV were predictors of survival. The response to HFOV, based on OI and P/F ratio, between 24 and 48 h of ventilation identified potential survivors. Also, lower positive end-expiratory pressure (PEEP) on CMV and shorter duration of CMV before initiation of HFOV were associated with survival.

CONCLUSIONS

Survival in pediatric ARDS patients treated with HFOV could be predicted by using trends of OI - with survivors showing a more rapid decline in OI between 24 and 48 h of initiation compared to non-survivors.

National Institute for the Infectious Diseases "L. Spallanzani", IRCCS. Recommendations for COVID-19 clinical management

On January 9 2020, the World Health Organization (WHO) declared the identification, by Chinese Health authorities, of a novel coronavirus, further classified as SARS-CoV-2 responsible of a disease (COVID-19) ranging from asymptomatic cases to severe respiratory involvement. On March 9 2020, WHO declared COVID-19 a global pandemic. Italy is the second most affected country by COVID-19 infection after China. The "L. Spallanzani" National Institute for the Infectious Diseases, IRCCS, Rome, Italy, has been the first Italian hospital to admit and manage patients affected by COVID-19. Hereby, we show our recommendations for the management of COVID-19 patients, based on very limited clinical evidences; they should be considered as expert opinions, which may be modified according to newly produced literature data.

International evidence-based guidelines on Point of Care Ultrasound (POCUS) for critically ill neonates and children issued by the POCUS Working Group of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC)

BACKGROUND

Point-of-care ultrasound (POCUS) is nowadays an essential tool in critical care. Its role seems more important in neonates and children where other monitoring techniques may be unavailable. POCUS Working Group of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC) aimed to provide evidence-based clinical guidelines for the use of POCUS in critically ill neonates and children.

METHODS

Creation of an international Euro-American panel of paediatric and neonatal intensivists expert in POCUS and systematic review of relevant literature. A literature search was performed, and the level of evidence was assessed according to a GRADE method. Recommendations were developed through discussions managed following a Quaker-based consensus technique and evaluating appropriateness using a modified blind RAND/UCLA voting method. AGREE statement was followed to prepare this document.

RESULTS

Panellists agreed on 39 out of 41 recommendations for the use of cardiac, lung, vascular, cerebral and abdominal POCUS in critically ill neonates and children. Recommendations were mostly (28 out of 39) based on moderate quality of evidence (B and C).

CONCLUSIONS

Evidence-based guidelines for the use of POCUS in critically ill neonates and children are now available. They will be useful to optimise the use of POCUS, training programs and further research, which are urgently needed given the weak quality of evidence available.

Endoplasmic reticulum stress potentiates the autophagy of alveolar macrophage to attenuate acute lung injury and airway inflammation

Endoplasmic reticulum (ER) stress has been reported to play a role in acute lung injury (ALI), yet the in-depth mechanism remains elusive. This study aims to investigate the effect of ER stress-induced autophagy of alveolar macrophage (AM) on acute lung injury (ALI) and airway inflammation using mouse models. ALI models were induced by intranasal instillation of lipopolysaccharide (LPS). The lung weight/body weight (LW/BW) ratio and excised lung gas volume (ELGV) in each group were measured. Mouse bronchoalveolar lavage fluid (BALF) was collected for cell sorting and protein concentration determination. Expression of tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) in lung tissues and BALF was also detected. Mouse AMs were isolated to observe the autophagy. Expression of GRP78, PERK, LC3I, LC3II and Beclin1 was further determined. The results indicated that tunicamycin (TM) elevated GRP78 and PERK expression of AMs in ALI mice in a dose-dependent manner. Low dosage of TM abated LC3I expression, increased LC3II and Beclin1 expression, triggered ER stress and AM autophagy, and alleviated pathological changes of AMs in ALI mice. Also, in ALI mice, low dosage of TM attenuated goblet cell proliferation of tracheal wall, and declined LW/BW ratio, ELGV, total cells and neutrophils, protein concentrations in BALF, and IL-6 and TNF-α expression in lung tissues and BALF. Collectively, this study suggests that a low dosage of TM-induced ER stress can enhance the autophagy of AM in ALI mice models, thus attenuating the progression of ALI and airway inflammation.

Respiratory Barrier as a Safeguard and Regulator of Defense Against Influenza A Virus and Streptococcus pneumoniae

The primary function of the respiratory system of gas exchange renders it vulnerable to environmental pathogens that circulate in the air. Physical and cellular barriers of the respiratory tract mucosal surface utilize a variety of strategies to obstruct microbe entry. Physical barrier defenses including the surface fluid replete with antimicrobials, neutralizing immunoglobulins, mucus, and the epithelial cell layer with rapidly beating cilia form a near impenetrable wall that separates the external environment from the internal soft tissue of the host. Resident leukocytes, primarily of the innate immune branch, also maintain airway integrity by constant surveillance and the maintenance of homeostasis through the release of cytokines and growth factors. Unfortunately, pathogens such as influenza virus and Streptococcus pneumoniae require hosts for their replication and dissemination, and prey on the respiratory tract as an ideal environment causing severe damage to the host during their invasion. In this review, we outline the host-pathogen interactions during influenza and post-influenza bacterial pneumonia with a focus on inter- and intra-cellular crosstalk important in pulmonary immune responses.

Early surfactant replacement guided by lung ultrasound in preterm newborns with RDS: the ULTRASURF randomised controlled trial

This study aimed to investigate whether using lung ultrasound (LUS) scores in premature newborns with respiratory distress syndrome (RDS) allows for earlier surfactant therapy (within the first 3 h of life) than using FiO₂ criteria. This was a randomised, non-blinded clinical trial conducted in a neonatal intensive care unit. The inclusion criteria were newborns with a gestational age of ≤ 32 weeks and RDS. Patients meeting the inclusion criteria were randomly assigned to two groups: the ultrasound group, administered surfactant based on LUS score and/or FiO₂ threshold, and the control group, guided by FiO₂ only. Fifty-six patients were included. The ultrasound group received surfactant earlier (1 h of life vs. 6 h, p < 0.001), with lower FiO₂ (25% vs. 30%, p = 0.016) and lower CO₂ (48 vs. 54, p = 0.011). After surfactant treatment, newborns in the ultrasound group presented a greater SpO₂ (p = 0.001) and SpO₂/FiO₂ ratio (p = 0.012).Conclusions: LUS score allowed an earlier surfactant therapy, reduced oxygen exposure early in life and a better oxygenation after the treatment. This early surfactant replacement may lead to reduced oxygen exposure. What is Known: • Lung ultrasound scores predict the need for surfactant therapy in premature newborns. What is New: • This study shows that using lung ultrasound scores improves the timeliness of surfactant replacement compared with using FiO₂ alone.

Endotracheal Surfactant Combined With Budesonide for Neonatal ARDS

Acute respiratory distress syndrome (ARDS) is a clinical condition characterized by acute diffuse inflammatory lung injury and severe hypoxemia. In 2017, the Montreux Consensus defined diagnostic criteria for ARDS in the neonatal period. The management of ARDS includes strict adherence to lung-protective ventilation strategies and therapeutic agents to improve gas exchange. We report two similar cases of premature infants with gestational ages of 23 and 24 weeks diagnosed with neonatal ARDS according to the Montreux definition. These patients developed acute worsening of oxygenation on the 30th and 28th day of life, respectively, while they were ventilated on volume-guarantee assist/control mode. Chest X-rays revealed bilateral diffuse opacity, there were no cardiogenic origins for pulmonary edema, and their oxygenation indexes were >8. Both cases fulfilled the neonatal ARDS criteria and the patients' clinical conditions were associated with late onset neonatal sepsis. After lung recruitment maneuver, the infants began HFO volume-guarantee ventilation and received surfactant treatment. Since they showed a poor short-term response, intratracheal surfactant of 100 mg/kg plus budesonide of 0.25 mg/kg were administered and their oxygenation indexes were reduced stepwise. Both patients survived and were discharged home with spontaneous breathing of room air. Neonatal ARDS is generally an underdiagnosed condition associated with sepsis, pneumonia, and meconium aspiration. Impaired surfactant activity and reduced lung compliance play important roles in its pathophysiology. To our knowledge, this is the first case report indicating the possible therapeutic role of budesonide plus surfactant in ARDS treatment. Since ARDS is an entity not recognized in newborns, we want to emphasize neonatal ARDS diagnosis and underline that the combination of budesonide and surfactant may be a novel therapeutic option in the treatment of ARDS.

Acute Respiratory Distress Syndrome Following Pediatric Trauma: Application of Pediatric Acute Lung Injury Consensus Conference Criteria

OBJECTIVES

To assess the incidence, severity, and outcomes of pediatric acute respiratory distress syndrome following trauma using Pediatric Acute Lung Injury Consensus Conference criteria.

DESIGN

Retrospective cohort study.

SETTING

Level 1 pediatric trauma center.

PATIENTS

Trauma patients less than or equal to 17 years admitted to the ICU from 2009 to 2017.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We queried electronic health records to identify patients meeting pediatric acute respiratory distress syndrome oxygenation criteria for greater than or equal to 6 hours and determined whether patients met complete pediatric acute respiratory distress syndrome criteria via chart review. We estimated associations between pediatric acute respiratory distress syndrome and outcome using generalized linear Poisson regression adjusted for age, injury mechanism, Injury Severity Score, and serious brain and chest injuries. Of 2,470 critically injured children, 103 (4.2%) met pediatric acute respiratory distress syndrome criteria. Mortality was 34.0% among pediatric acute respiratory distress syndrome patients versus 1.7% among patients without pediatric acute respiratory distress syndrome (adjusted relative risk, 3.7; 95% CI, 2.0-6.9). Mortality was 50.0% for severe pediatric acute respiratory distress syndrome at onset, 33.3% for moderate, and 30.5% for mild. Cause of death was neurologic in 60.0% and multiple organ failure in 34.3% of pediatric acute respiratory distress syndrome nonsurvivors versus neurologic in 85.4% of nonsurvivors without pediatric acute respiratory distress syndrome (p = 0.001). Among survivors, 77.1% of pediatric acute respiratory distress syndrome patients had functional disability at discharge versus 30.7% of patients without pediatric acute respiratory distress syndrome patients (p < 0.001), and only 17.5% of pediatric acute respiratory distress syndrome patients discharged home without ongoing care versus 86.4% of patients without pediatric acute respiratory distress syndrome (adjusted relative risk, 1.5; 1.1-2.1).

CONCLUSIONS

Incidence and mortality associated with pediatric acute respiratory distress syndrome following traumatic injury are substantially higher than previously recognized, and pediatric acute respiratory distress syndrome development is associated with high risk of poor outcome even after adjustment for underlying injury type and severity.

Improved oxygenation following methylprednisolone therapy and survival in paediatric acute respiratory distress syndrome

Background

Methylprednisolone remains a commonly used ancillary therapy for paediatric acute respiratory distress syndrome (PARDS), despite a lack of level 1 evidence to justify its use. When planning prospective trials it is useful to define response to therapy and to identify if there is differential response in certain patients, i.e. existence of ‘responders’ and ‘non responders’ to therapy. This retrospective, observational study carried out in 2 tertiary referral paediatric intensive care units aims to characterize the change in Oxygen Saturation Index, following the administration of low dose methylprednisolone in a cohort of patients with PARDS, to identify what proportion of children treated demonstrated response, whether any particular characteristics predict response to therapy, and to determine if a positive response to corticosteroids is associated with reduced Paediatric Intensive Care Unit mortality.

Methods

All patients who received prolonged, low dose, IV methylprednisolone for the specific indication of PARDS over a 5-year period (2011–2016) who met the PALICC criteria for PARDS at the time of commencement of steroid were included (n = 78).OSI was calculated four times per day from admission until discharge from PICU (or death). Patients with ≥20% improvement in their mean daily OSI within 72 hours of commencement of methylprednisolone were classified as ‘responders’. Primary outcome measure was survival to PICU discharge.

Results

Mean OSI of the cohort increased until the day of steroid commencement then improved thereafter. 59% of patients demonstrated a response to steroids. Baseline characteristics were similar between responders and non-responders. Survival to PICU discharge was significantly higher in ‘responders’ (74% vs 41% OR 4.14(1.57–10.87) p = 0.004). On multivariable analysis using likely confounders, response to steroid was an independent predictor of survival to PICU discharge (p = 0.002). Non-responders died earlier after steroid administration than responders (p = 0.003).

Conclusions

An improvement in OSI was observed in 60% of patients following initiation of low dose methylprednisolone therapy in this cohort of patients with PARDS. Baseline characteristics fail to demonstrate a difference between responders and non-responders. A 20% improvement in OSI after commencement of methylprednisolone was independently predictive of survival, Prospective trials are needed to establish if there is a benefit from this therapy.

A Phase II randomized controlled trial for lung and diaphragm protective ventilation (Real-time Effort Driven VENTilator management)

Lung Protective Mechanical Ventilation (MV) of critically ill adults and children is lifesaving but it may decrease diaphragm contraction and promote Ventilator Induced Diaphragm Dysfunction (VIDD). An ideal MV strategy would balance lung and diaphragm protection. Building off a Phase I pilot study, we are conducting a Phase II controlled clinical trial that seeks to understand the evolution of VIDD in critically ill children and test whether a novel computer-based approach (Real-time Effort Driven ventilator management (REDvent)) can balance lung and diaphragm protective ventilation to reduce time on MV. REDvent systematically adjusts PEEP, FiO₂, inspiratory pressure, tidal volume and rate, and uses real-time measures from esophageal manometry to target normal levels of patient effort of breathing. This trial targets 276 children with pulmonary parenchymal disease. Patients are randomized to REDvent vs. usual care for the acute phase of MV (intubation to first Spontaneous Breathing Trial (SBT)). Patients in either group who fail their first SBT will be randomized to REDvent vs usual care for weaning phase management (interval from first SBT to passing SBT). The primary clinical outcome is length of weaning, with several mechanistic outcomes. Upon completion, this study will provide important information on the pathogenesis and timing of VIDD during MV in children and whether this computerized protocol targeting lung and diaphragm protection can lead to improvement in intermediate clinical outcomes. This will form the basis for a larger, Phase III multi-center study, powered for key clinical outcomes such as 28-day ventilator free days. Clinical Trials Registration: NCT03266016.

Morbidity and Mortality Among Critically Injured Children With Acute Respiratory Distress Syndrome

OBJECTIVES

To evaluate morbidity and mortality among critically injured children with acute respiratory distress syndrome.

DESIGN

Retrospective cohort study.

SETTING

Four-hundred sixty Level I/II adult or pediatric trauma centers contributing to the National Trauma Data Bank.

PATIENTS

One hundred forty-six thousand fifty-eight patients less than 18 years old admitted to an ICU with traumatic injury from 2007 to 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We assessed in-hospital mortality and need for postdischarge care among patients with and without acute respiratory distress syndrome and hospital resource utilization and discharge disposition among survivors. Analyses were adjusted for underlying mortality risk (age, Injury Severity Score, serious brain or chest injury, and admission heart rate and hypotension) and year, transfer status, and facility trauma level designation. Acute respiratory distress syndrome occurred in 2,590 patients (1.8%). Mortality was 20.0% among acute respiratory distress syndrome patients versus 4.3% among nonacute respiratory distress syndrome patients, with an adjusted relative risk of 1.76 (95% CI, 1.52-2.04). Postdischarge care was required in an additional 44.8% of acute respiratory distress syndrome patients versus 16.0% of patients without acute respiratory distress syndrome (adjusted relative risk, 3.59; 2.87-4.49), with only 35.1% of acute respiratory distress syndrome patients discharging to home versus 79.8% of patients without acute respiratory distress syndrome. Acute respiratory distress syndrome mortality did not change over the 10-year study period (adjusted relative risk, 1.01/yr; 0.96-1.06) nor did the proportion of acute respiratory distress syndrome patients requiring postdischarge care (adjusted relative risk, 1.04/yr; 0.97-1.11). Duration of ventilation, ICU stay, and hospital stay were all significantly longer among acute respiratory distress syndrome survivors. Tracheostomy placement occurred in 18.4% of acute respiratory distress syndrome survivors versus 2.1% of patients without acute respiratory distress syndrome (adjusted relative risk, 3.10; 2.59-3.70).

CONCLUSIONS

Acute respiratory distress syndrome development following traumatic injury in children is associated with significantly increased risk of morbidity and mortality, even after adjustment for injury severity and hemodynamic abnormalities. Outcomes have not improved over the past decade, emphasizing the need for new therapeutic interventions, and prevention strategies for acute respiratory distress syndrome among severely injured children.

Ventilator-induced lung injury in children: a reality?

Mechanical ventilation (MV) is inextricably linked to the care of critically ill patients admitted to the paediatric intensive care unit (PICU). Even today, little evidence supports best MV practices for life-threatening acute respiratory failure in children. However, careful attention must be paid because this life-saving technique induces pulmonary inflammation that aggravates pre-existing lung injury, a concept that is known as ventilator-induced lung injury (VILI). The delivery of too large tidal volumes (Vt) (i.e., volutrauma) and repetitive opening and closure of alveoli (i.e., atelectrauma) are two key mechanisms underlying VILI. Despite the knowledge of these mechanisms, the clinical relevance of VILI in critically ill children is poorly understood as almost all of our knowledge has been obtained from studies in adults or experimental studies mimicking the adult critical care situation. This leaves the question if VILI is relevant in the paediatric context. In fact, limited paediatric experimental data showed that the use of large, supraphysiologic Vt resulted in less inflammation and injury in paediatric animal models compared to adult models. Furthermore, the association between large Vt and adverse outcome has not been confirmed and the issue of setting positive end-expiratory pressure (PEEP) to prevent atelectrauma has hardly been studied in paediatric clinical studies. Hence, even today, the question whether or not there VILI is relevant in pediatric critical remains to be answered. Consequently, how MV is used remains thus based on institutional preferences, personal beliefs and clinical data extrapolated from adults. This signifies the need for clinical and experimental studies in order to better understand the use and effects of MV in paediatric patients with or without lung injury.

Steroids in pediatric acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a complex entity with high potential for harm and healthcare resource utilization. Despite multiple clinical advances in its ventilatory management, ARDS continues to be one of the most challenging disease processes for intensivists. It continues to lack a direct, proven and desperately needed effective therapeutic intervention. Given their biologic rationale, corticosteroids have been widely used by clinicians and considered useful by many in the management of ARDS since its first description. Adult data is abundant, yet contradictory. Controversy remains regarding the routine use of corticosteroids in ARDS. Therefore, widespread evidence-based recommendations for this heterogeneous disease process have not been made. In this article, our aim was to provide a summary of available evidence for the role of steroids in the treatment of ARDS, while giving special focus on pediatric ARDS (PARDS).

Severity and Mortality Predictors of Pediatric Acute Respiratory Distress Syndrome According to the Pediatric Acute Lung Injury Consensus Conference Definition

OBJECTIVES

The objective of this study was to assess the prevalence, severity, and outcomes of pediatric acute respiratory distress syndrome in a resource-limited country. In addition, we sought to explore the predisposing factors that predicted the initial severity, a change from mild to moderate-severe severity, and mortality.

DESIGN

Retrospective study.

SETTING

PICU in Songklanagarind Hospital, Songkhla, Thailand.

PATIENTS

Children 1 month to 15 years old with acute respiratory failure admitted to the PICU from January 2013 to December 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

From a total of 1,738 patients admitted to PICU, 129 patients (prevalence 7.4%) were diagnosed as pediatric acute respiratory distress syndrome using the Pediatric Acute Lung Injury Consensus Conference definition. The patients were categorized by severity. Fifty-seven patients (44.2%) were mild, 35 (27.1%) were moderate, and 37 (28.1%) were severe. After multivariable analysis was performed, factors significantly associated with moderate to severe disease at the initial diagnosis were Pediatric Risk of Mortality III score (odds ratio, 1.08; 95% CI, 1.03-1.15; p = 0.004), underlying oncologic/hematologic disorder (odds ratio, 0.32; 95% CI, 0.12-0.77; p = 0.012), and serum albumin level (odds ratio, 0.46; 95% CI, 0.27-0.80; p = 0.006), whereas underlying oncologic/hematologic disorder (odds ratio, 5.33; 95% CI, 1.33-21.4) and hemoglobin (odds ratio, 0.63; 95% CI, 0.44-0.89) predicted the progression of this syndrome within 7 days. The 30-day all-cause mortality rate was 51.2% (66/129). The predictors of mortality were the Pediatric Risk of Mortality III score (odds ratio, 1.12; 95% CI, 1.02-1.24; p = 0.017), underlying oncologic/hematologic disorder (odds ratio, 7.81; 95% CI, 2.18-27.94; p = 0.002), receiving systemic steroids (odds ratio, 4.04; 95% CI, 1.25-13.03; p = 0.019), having air leak syndrome (odds ratio, 5.45; 95% CI, 1.57-18.96; p = 0.008), and presenting with multiple organ dysfunction (odds ratio, 7.41; 95% CI, 2.00-27.36; p = 0.003).

CONCLUSIONS

The prevalence and mortality rate of pediatric acute respiratory distress syndrome in a developing country are high. The oncologic/hematologic comorbidity had a significant impact on the severity of progression and mortality.

Extra-corporeal membrane oxygenation in paediatric acute respiratory distress syndrome: overrated or underutilized?

Extracorporeal membrane oxygenation (ECMO) is a modified form of cardiopulmonary bypass which may provide support for severe cardiorespiratory failure including paediatric acute respiratory distress syndrome (PARDS). While ECMO was initially demonstrated to successfully support neonates with severe respiratory failure, the use of ECMO has expanded rapidly to support both paediatric and adult respiratory failure. Extracorporeal Life Support Organization (ELSO) registry data shows that the use of ECMO for paediatric respiratory failure has expanded rapidly over the past decades with increasing use of venovenous ECMO. Despite the increasing complexity of children supported by ECMO for ARDS, outcomes have remained consistent with survival to hospital discharge greater than 50%. ECMO complications are still common and potentially devastating, especially neurological complications. There is grade 1 evidence to support the use of ECMO in both neonatal and adult respiratory failure but evidence in paediatric respiratory failure is confined to case series and case-control studies. While there are no published guidelines for use of ECMO in PARDS, in particular no clearly defined inclusion and exclusion criteria, current evidence suggests that children with severe ARDS may benefit from ECMO support, with survival to hospital discharge equivalent or better than conventional management in children with severe ARDS.

Predictors of mortality after admission to pediatric intensive care unit in oncohematologic patients without history of hematopoietic stem cell transplantation: A single-center experience

BACKGROUND

Pediatric oncohematologic patients are a high-risk population for clinical deterioration that might require pediatric intensive care unit (PICU) admission. Several studies have described outcomes and mortality predictors for patients post hematopoietic stem cell transplantation (HSCT), but fewer data exist regarding the category of non-HSCT patients.

PROCEDURE

All oncohematologic non-HSCT patients ≤18 years requiring PICU admission from 1998 to 2015 in our tertiary-care academic hospital were retrospectively evaluated by means of the pediatric hematology-oncology unit database and the Italian PICUs data network database. We assessed the relation between demographic and clinical characteristics and 90-day mortality after PICU admission.

RESULTS

Of 3750 hospitalized oncohematologic patients, 3238 were non-HSCT and 63 (2%) of them were admitted to the PICU. Patients were mainly affected by hematological malignancies (70%) and mostly were in the induction-therapy phase. The main reasons for admission were respiratory failure (40%), sepsis (25%), and seizures (16%). The median PICU stay was 5 days (range 1-107). The mortality rate at PICU discharge was 30%, and at 90 days it was 35%. Fifty-five percent of deaths happened in the first 2 days of the PICU stay. Cardiac arrest (P = .007), presence of disseminated intravascular coagulation (DIC, P = .007), and acute kidney injury (AKI) at PICU admission (P < .001) and during PICU stay (P = .021) were significant predictors of mortality in the multivariate analysis. Respiratory failure and mechanical ventilation were not associated with mortality.

CONCLUSIONS

A relatively small percentage of non-HSCT patients required PICU admission, but the mortality rate was still high. Hemodynamic instability, DIC, and AKI, but not respiratory failure, were significant predictors of mortality.

The role of point-of-care ultrasound in pediatric acute respiratory distress syndrome: emerging evidence for its use

Pediatric acute respiratory distress syndrome (PARDS) remains an important cause of significant morbidity and mortality. The 2015 PALICC definition of PARDS requires chest imaging to diagnose the presence of new pulmonary infiltrate(s). Traditionally chest radiography or computerised tomography have been used. However, these carry the limitations of exposure to ionizing radiation, need to transfer the critically unwell child, lag-time with clinical correlation and lack of immediate results. The use of point of care ultrasound (POCUS) has been well established in adult emergency medicine and critical care. Furthermore, the adult literature clearly demonstrates that lung POCUS is a safe and validated tool, which is highly sensitive and specific when compared to chest radiography for differentiating the causes of respiratory failure, including ARDS. Whilst pediatric specific data is limited, it has been shown that the signs seen in adults are reproducible in critically ill neonates and children. Furthermore, the numerous benefits of POCUS in the paediatric setting are compelling and include lack of ionizing radiation, immediate feedback, promoting time at the bedside of the critically unwell child, and ease of serial assessments. This review article presents the emerging evidence demonstrating that lung POCUS can be used not only to support the diagnosis of pediatric ARDS, but also to assess for complications, monitor progression and thus guide management. We hope it will stimulate much needed collaborative research into this exciting field of imaging and its applications to PARDS and beyond.

Clinical trials and future directions in pediatric acute respiratory distress syndrome

The pediatric acute respiratory distress syndrome (PARDS), a description specific for children with acute respiratory distress syndrome (ARDS), was proposed in the recent Pediatric Acute Lung Injury Consensus Conference (PALICC, 2015). This recent standardization of PARDS diagnosis is expected to aid in uniform earlier recognition of the entity, enable use of consistent management strategies and potentially increase the ease of enrollment in future PARDS clinical trials-all of which are expected to optimize outcomes in PARDS. Clinical trials in PARDS are few but ongoing studies are expected to lay the foundation for future clinical studies. The Randomized Evaluation of Sedation Titration for Respiratory Failure trial (RESTORE) trial has revealed that a goal directed sedation protocol does not reduce the duration of invasive ventilation in critically ill children. PROSpect trial is a large multi-institute clinical trial that is expected to reveal optimal ventilation strategies and patient positioning (supine vs. prone) in patients with severe PARDS. The PARDS neuromuscular blockade (NMB) study is expected to yield important information about the impact of active NMB on PARDS outcomes. Information from these studies could be used to design future clinical trials in PARDS and to lessen the anecdotal or extrapolated experiences from adult clinical studies that often guide clinical practices in PARDS management. Finally, it is expected that these definitions and management strategies will be revised periodically as our understanding of PARDS evolves. Emerging data on PARDS subtypes suggest that patient heterogeneity is an important factor in designing these clinical trials.

Sedation strategies in children with pediatric acute respiratory distress syndrome (PARDS)

In this review, we discuss the changing landscape of sedation in mechanically ventilated children with pediatric acute respiratory distress syndrome (PARDS). While previous approaches advocated for early and deep sedation with benzodiazepines, emerging literature has highlighted the benefits of light sedation and use of non-benzodiazepine sedating agents, such as dexmedetomidine. Recent studies have emphasized the importance of monitoring multiple factors including, but not limited to, sedation depth, analgesia efficacy, opiate withdrawal, and development of delirium. Through this approach, we hope to improve PARDS outcomes. Overall, more research is needed to further our understanding of the best sedation strategies in children with PARDS.

Risk Factors on Hospital Arrival for Acute Respiratory Distress Syndrome Following Pediatric Trauma

OBJECTIVES

To determine risk factors identifiable at hospital arrival associated with acute respiratory distress syndrome development among critically injured children.

DESIGN

Retrospective cohort study.

SETTING

Level I or II adult or pediatric trauma centers contributing to the National Trauma Data Bank from 2007 to 2016.

PATIENTS

Patients less than 18 years admitted to an ICU with traumatic injury.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We determined associations between patient, injury, and clinical characteristics present at hospital arrival with development of acute respiratory distress syndrome recorded as a hospital complication. Acute respiratory distress syndrome occurred in 1.8% of 146,058 critically injured children (n = 2,590). The only demographic factor associated with higher risk of developing acute respiratory distress syndrome on multivariable analysis was African American race (relative risk, 1.42 vs white; 95% CI, 1.13-1.78). Injury characteristics included firearm injuries (relative risk 1.93; 1.50-2.48) and motor vehicle crashes (relative risk, 1.91; 1.57-2.31) relative to falls; spine (relative risk, 1.39; 1.20-1.60), chest (relative risk, 1.36; 1.22-1.52), or lower extremity injuries (relative risk, 1.26; 1.10-1.44); amputations (relative risk, 2.10; 1.51-2.91); and more severe injury (relative risk, 3.69 for Injury Severity Score 40-75 vs 1-8; 2.50-5.44). Clinical variables included abnormal respiratory status (intubated relative risk, 1.67; 1.23-2.26 and hypopnea relative risk, 1.23; 1.05-1.45 and tachypnea relative risk, 1.26; 1.10-1.44) and lower Glasgow Coma Scale score (relative risk, 5.61 for Glasgow Coma Scale score 3 vs 15; 4.44-7.07).

CONCLUSIONS

We provide the first description of the incidence of and risk factors for acute respiratory distress syndrome among pediatric trauma patients. Improved understanding of the risk factors associated with acute respiratory distress syndrome following pediatric trauma may help providers anticipate its development and intervene early to improve outcomes for severely injured children.

Airway Pressure Release Ventilation in Pediatric Acute Respiratory Distress Syndrome. A Randomized Controlled Trial

RATIONALE

Although case series describe benefits of airway pressure release ventilation (APRV), this mode of ventilation has not been evaluated against the conventional low-tidal volume ventilation (LoTV) in children with acute respiratory distress syndrome (ARDS).

OBJECTIVES

To compare the effect of APRV and conventional LoTV on ventilator-free days in children with ARDS.

METHODS

This open-label, parallel-design randomized controlled trial was conducted in a 15-bed ICU. Children aged 1 month to 12 years satisfying the modified Berlin definition were included. We excluded children with air leaks, increased intracranial pressure, poor spontaneous breathing efforts, chronic lung disease, and beyond 24 hours of ARDS diagnosis or 72 hours of ventilation. Children were randomized using unstratified, variable-sized block technique. A priori interim analysis was planned at 50% enrollment. All enrolled children were followed up until 180 days after enrollment or death, whichever was earlier.

MEASUREMENTS AND MAIN RESULTS

The trial was terminated after 50% enrollment (52 children) when analysis revealed higher mortality in the intervention arm. Ventilator-free days were statistically similar in both arms (P = 0.23). The 28-day all-cause mortality was 53.8% in APRV as compared with 26.9% among control subjects (risk ratio, 2.0; 95% confidence interval, 0.97-4.1; Fisher exact P = 0.089). The multivariate-adjusted risk ratio of death for APRV compared with LoTV was 2.02 (95% confidence interval, 0.99-4.12; P = 0.05). Higher mean airway pressures, greater spontaneous breathing, and early improvement in oxygenation were seen in the intervention arm.

CONCLUSIONS

APRV, as a primary ventilation strategy in children with ARDS, was associated with a trend toward higher mortality compared with the conventional LoTV. Limitations should be considered while interpreting these results. Clinical trial registered with www.clinicaltrials.gov (NCT02167698) and Clinical Trials Registry of India (CTRI/2014/06/004677).

The Association Between Inhaled Nitric Oxide Treatment and ICU Mortality and 28-Day Ventilator-Free Days in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

To investigate the association between inhaled nitric oxide treatment and ICU mortality and 28-day ventilator-free days in pediatric acute respiratory distress syndrome.

DESIGN

Retrospective cohort study. A propensity score for inhaled nitric oxide treatment was developed and used in the analysis.

SETTING

Two quaternary care PICUs.

PATIENTS

Children with pediatric acute respiratory distress syndrome.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 499 children enrolled in this study with 143 (28.7%) receiving inhaled nitric oxide treatment. Children treated with inhaled nitric oxide were more likely to have a primary diagnosis of pneumonia (72% vs 54.8%; p < 0.001), had a higher initial oxygenation index (median 16.9 [interquartile range, 10.1-27.3] vs 8.5 [interquartile range, 5.8-12.2]; p < 0.001), and had a higher 72-hour maximal Vasoactive-Inotrope Score (median 15 [interquartile range, 6-25] vs 8 [interquartile range, 0-17.8]; p < 0.001) than those not receiving inhaled nitric oxide. Mortality was higher in the inhaled nitric oxide treatment group (25.2% vs 16.3%; p = 0.02), and children in this group had fewer 28-day ventilator-free days (10 d [interquartile range, 0-18 d] vs 17 d (interquartile range 5.5-22 d]; p < 0.0001). We matched 176 children based on propensity score for inhaled nitric oxide treatment. In the matched cohort, inhaled nitric oxide treatment was not associated with mortality (odds ratio, 1.3 [95% CI, 0.56-3.0]) or 28-day ventilator-free days (incidence rate ratio, 0.91 [95% CI, 0.80-1.04]). These results remained consistent in the entire study cohort when the propensity score for inhaled nitric oxide treatment was used for either inverse probability weighting or stratification in regression modeling with the exception that subjects treated with inhaled nitric oxide were more likely to have 0 ventilator-free days (p ≤ 0.02). In secondary analysis stratified by oxygenation response, inhaled nitric oxide treatment was not associated with mortality or 28-day ventilator-free days in children with a positive oxygenation response (all p > 0.2) CONCLUSIONS:: Treatment with inhaled nitric oxide in pediatric acute respiratory distress syndrome is not associated with improvement in either mortality or ventilator-free days and may be associated with harm. Further prospective trials are required to define the role of inhaled nitric oxide treatment in pediatric acute respiratory distress syndrome.

A shared protocol for porcine surfactant use in pediatric acute respiratory distress syndrome: a feasibility study

Background

Pediatric ARDS still represents a difficult challenge in Pediatric Intensive Care Units (PICU). Among different treatments proposed, exogenous surfactant showed conflicting results. Aim of this multicenter retrospective observational study was to evaluate whether poractant alfa use in pediatric ARDS might improve gas exchange in children less than 2 years old, according to a shared protocol.

Methods

The study was carried out in fourteen Italian PICUs after dissemination of a standardized protocol for surfactant administration within the Italian PICU network. The protocol provides the administration of surfactant (50 mg/kg) divided in two doses: the first dose is used as a bronchoalveolar lavage while the second as supplementation. Blood gas exchange variations before and after surfactant use were recorded.

Results

Sixty-nine children, age 0–24 months, affected by Acute Respiratory Distress Syndrome treated with exogenous porcine surfactant were enrolled. Data collection consisted of patient demographics, respiratory variables and arterial blood gas analysis. The most frequent reasons for PICU admission were acute respiratory failure, mainly bronchiolitis and pneumonia, and septic shock. Fifty-four children (78.3%) had severe ARDS (define by oxygen arterial pressure and inspired oxygen fraction ratio (P/F) < 100), 15 (21.7%) had moderate ARDS (100 < P/F < 200). PO₂, P/F, Oxygenation Index (OI) and pH showed a significant improvement after surfactant use with respect to baseline (p < 0.001 at each included time-point for each parameter). No significant difference in blood gas variations were observed among four different subgroups of diseases (bronchiolitis, pneumonia, septic shock and others). Overall, 11 children died (15.9%) and among these, 10 (90.9%) had complex chronic conditions. Two children (18.2%) died while being treated with Extracorporeal Membrane Oxygenation (ECMO). Mortality for severe pARDS was 20.4%.

Conclusion

The use of porcine Surfactant improves oxygenation, P/F ratio, OI and pH in a population of children with moderate or severe pARDS caused by multiple diseases. A shared protocol seems to be a good option to obtain the same criteria of enrollment among different PICUs and define a unique way of use and administration of the drug for future studies.

Clinical Profile and Predictors of Outcome of Pediatric Acute Respiratory Distress Syndrome in a PICU: A Prospective Observational Study

OBJECTIVES

To study the clinical profile, predictors of mortality, and outcomes of pediatric acute respiratory distress syndrome.

DESIGN

A prospective observational study.

SETTING

PICU, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

PATIENTS

All children (age > 1 mo to < 14 yr) admitted in PICU with a diagnosis of pediatric acute respiratory distress syndrome (as per Pediatric Acute Lung Injury Consensus Conference definition) from August 1, 2015, to November 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Out of 1,215 children admitted to PICU, 124 (11.4%) had pediatric acute respiratory distress syndrome. Fifty-six children (45.2%) died. Median age was 2.75 years (1.0-6.0 yr) and 66.9% were male. Most common primary etiologies were pneumonia, severe sepsis, and scrub typhus. Ninety-seven children (78.2%) were invasively ventilated. On multiple logistic regressions, Lung Injury Score (p = 0.004), pneumothorax (p = 0.012), acute kidney injury at enrollment (p = 0.033), FIO2-D1 (p = 0.018), and PaO2/FIO2 ratio-D7 (p = 0.020) were independent predictors of mortality. Positive fluid balance (a cut-off value > 102.5 mL/kg; p = 0.016) was associated with higher mortality at 48 hours. Noninvasive oxygenation variables like oxygenation saturation index and saturation-FIO2 ratio were comparable to previously used invasive variables (oxygenation index and PaO2/FIO2 ratio) in monitoring the course of pediatric acute respiratory distress syndrome.

CONCLUSIONS

Pediatric acute respiratory distress syndrome contributes to a significant burden in the PICU of a developing country and is associated with significantly higher mortality. Infection remains the most common etiology. Higher severity of illness scores at admission, development of pneumothorax, and a positive fluid balance at 48 hours predicted poor outcome.

Estimation of early life endogenous surfactant pool and CPAP failure in preterm neonates with RDS

Background

It is not known if the endogenous surfactant pool available early in life is associated with the RDS clinical course in preterm neonates treated with CPAP. We aim to clarify the clinical factors affecting surfactant pool in preterm neonates and study its association with CPAP failure.

Methods

Prospective, pragmatic, blind, cohort study. Gastric aspirates were obtained (within the first 6 h of life and before the first feeding) from 125 preterm neonates with RDS. Surfactant pool was measured by postnatal automated lamellar body count based on impedancemetry, without any pre-analytical treatment. A formal respiratory care protocol based on European guidelines was applied. Clinical data and perinatal risk factors influencing RDS severity or lamellar body count were real-time recorded. Investigators performing lamellar body count were blind to the clinical data and LBC was not used in clinical practice.

Results

Multivariate analysis showed gestational age to be the only factor significantly associated with lamellar body count (standardized β:0.233;p = 0.023). Lamellar body count was significantly higher in neonates with CPAP success (43.500 [23.750–93.750]bodies/μL), than in those failing CPAP (20.500 [12.250–49.750] bodies/μL;p = 0.0003).LBC had a moderate reliability to detect CPAP failure (AUC: 0.703 (0.615–0.781);p < 0.0001; best cut-off: ≤30,000 bodies/μL). Upon adjustment for possible confounders, neither lamellar body count, nor its interaction factor with gestational age resulted associated with CPAP failure.

Conclusions

Early postnatal lamellar body count on gastric aspirates in CPAP-treated preterm neonates with RDS is significantly influenced only by gestational age. Lamellar bodies are not associated with CPAP failure. Thus, the endogenous surfactant pool available early in life only has a moderate reliability to predict CPAP failure.

Association Between Tidal Volumes Adjusted for Ideal Body Weight and Outcomes in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

The impact of tidal volume on outcomes in mechanically ventilated children with pediatric acute respiratory distress syndrome remains unclear. To date, observational investigations have failed to calculate tidal volume based on standardized corrections of weight. We investigated the impact of tidal volume on mortality and probability of extubation in pediatric acute respiratory distress syndrome using ideal body weight-adjusted tidal volume.

DESIGN

Retrospective analysis of an ongoing prospective cohort of pediatric acute respiratory distress syndrome patients. Tidal volume was calculated based on actual body weight and two different formulations of ideal body weight.

SETTING

PICU at a large, tertiary care children's hospital.

PATIENTS

Pediatric acute respiratory distress syndrome patients on conventional ventilation with a documented height or length.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 483 patients with a measured height or length at pediatric acute respiratory distress syndrome onset included in the final analysis, with 73 nonsurvivors (15%). At 24 hours, there remained 400 patients on conventional ventilation. When calculating tidal volume based on ideal body weight by either method, volumes were larger both at onset and at 24 hours compared with tidal volume based on actual body weight (all p < 0.001), and the proportion of patients being ventilated with tidal volumes greater than 10 mL/kg based on ideal body weight was larger both at onset (12.4% and 15.5%) and 24 hours (10.3% and 11.5%) compared with actual body weight at onset (3.5%) and 24 hours (4.0%) (all p < 0.001). Tidal volume, based on both actual body weight and ideal body weight, was not associated with either increased mortality or decreased probability of extubation after adjusting for oxygenation index in the whole cohort, whereas associations between higher tidal volume and poor outcomes were seen in subgroup analyses in overweight children and in severe pediatric acute respiratory distress syndrome.

CONCLUSIONS

Our retrospective analysis of a cohort of pediatric acute respiratory distress syndrome patients did not find a consistent association between tidal volume adjusted for ideal body weight and outcomes, although an association may exist in certain subgroups. Although it remains to be shown in a prospective trial whether high volumes or pressures are injurious in pediatric acute respiratory distress syndrome, tidal volume is likely an imprecise parameter for titrating lung-protective ventilation.

Neutrophil Dysfunction in the Airways of Children with Acute Respiratory Failure Due to Lower Respiratory Tract Viral and Bacterial Coinfections

Neutrophils are recruited to the airways of patients with acute respiratory distress syndrome (ARDS) where they acquire an activated pro-survival phenotype with an enhanced respiratory burst thought to contribute to ARDS pathophysiology. Our in vitro model enables blood neutrophil transepithelial migration into cell-free tracheal aspirate fluid from patients to recapitulate the primary airway neutrophil phenotype observed in vivo. Neutrophils transmigrated through our model toward airway fluid from children with lower respiratory viral infections coinfected with bacteria had elevated levels of neutrophil activation markers but paradoxically exhibited an inability to kill bacteria and a defective respiratory burst compared with children without bacterial coinfection. The airway fluid from children with bacterial coinfections had higher levels of neutrophil elastase activity, as well as myeloperoxidase levels compared to children without bacterial coinfection. Neutrophils transmigrated into the aspirate fluid from children with bacterial coinfection showed decreased respiratory burst and killing activity against H. influenzae and S. aureus compared to those transmigrated into the aspirate fluid from children without bacterial coinfection. Use of a novel transmigration model recapitulates this pathological phenotype in vitro that would otherwise be impossible in a patient, opening avenues for future mechanistic and therapeutic research.

Outcomes of Children With Critical Bronchiolitis Meeting at Risk for Pediatric Acute Respiratory Distress Syndrome Criteria

OBJECTIVES

New definitions of pediatric acute respiratory distress syndrome include criteria to identify a subset of children "at risk for pediatric acute respiratory distress syndrome." We hypothesized that, among PICU patients with bronchiolitis not immediately requiring invasive mechanical ventilation, those meeting at risk for pediatric acute respiratory distress syndrome criteria would have worse clinical outcomes, including higher rates of pediatric acute respiratory distress syndrome development.

DESIGN

Single-center, retrospective chart review.

SETTING

Mixed medical-surgical PICU within a tertiary academic children's hospital.

PATIENTS

Children 24 months old or younger admitted to the PICU with a primary diagnosis of bronchiolitis from September 2013 to April 2014. Children intubated before PICU arrival were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Collected data included demographics, respiratory support, oxygen saturation, and chest radiograph interpretation by staff radiologist. Oxygen flow (calculated as FIO2 × flow rate [L/min]) was calculated when oxygen saturation was 88-97%. The median age of 115 subjects was 5 months (2-11 mo). Median PICU length of stay was 2.8 days (1.5-4.8 d), and median hospital length of stay was 5 days (3-10 d). The criteria for at risk for pediatric acute respiratory distress syndrome was met in 47 of 115 subjects (40.9%). Children who were at risk for pediatric acute respiratory distress syndrome were more likely to develop pediatric acute respiratory distress syndrome (15/47 [31.9%] vs 1/68 [1.5%]; p < 0.001), had longer PICU length of stay (4.6 d [2.8-10.2 d] vs 1.9 d [1.0-3.1 d]; p < 0.001) and hospital length of stay (8 d [5-16 d] vs 4 d [2-6 d]; p < 0.001), and increased need for invasive mechanical ventilation (16/47 [34.0%] vs 2/68 [2.9%]; p < 0.001), compared with those children who did not meet at risk for pediatric acute respiratory distress syndrome criteria.

CONCLUSIONS

Our data suggest that the recent definition of at risk for pediatric acute respiratory distress syndrome can successfully identify children with critical bronchiolitis who have relatively unfavorable clinical courses.

[Admission, discharge and triage guidelines for paediatric intensive care units in Spain]

A paediatric intensive care unit (PICU) is a separate physical facility or unit specifically designed for the treatment of paediatric patients who, because of the severity of illness or other life-threatening conditions, require comprehensive and continuous inten-sive care by a medical team with special skills in paediatric intensive care medicine. Timely and personal intervention in intensive care reduces mortality, reduces length of stay, and decreases cost of care. With the aim of defending the right of the child to receive the highest attainable standard of health and the facilities for the treatment of illness and rehabilitation, as well as ensuring the quality of care and the safety of critically ill paediatric patients, the Spanish Association of Paediatrics (AEP), Spanish Society of Paediatric Intensive Care (SECIP) and Spanish Society of Critical Care (SEMICYUC) have approved the guidelines for the admission, discharge and triage for Spanish PICUs. By using these guidelines, the performance of Spanish paediatric intensive care units can be optimised and paediatric patients can receive the appropriate level of care for their clinical condition.

Feasibility of an alternative, physiologic, individualized open-lung approach to high-frequency oscillatory ventilation in children

Background

High-frequency oscillatory ventilation (HFOV) is a common but unproven management strategy in paediatric critical care. Oscillator settings have been traditionally guided by patient age and/or weight rather than by lung mechanics, thereby potentially negating any beneficial effects. We have adopted an open-lung HFOV strategy based on a corner frequency approach using an initial incremental–decremental mean airway pressure titration manoeuvre, a high frequency (8–15 Hz), and high power to initially target a proximal pressure amplitude (∆P_proximal) of 70–90 cm H₂O, irrespective of age or weight.

Methods

We reviewed prospectively collected data on patients < 18 years of age who were managed with HFOV for acute respiratory failure. We measured metrics for oxygenation, ventilation, and haemodynamics as well as the use of sedative-analgesic medications and neuromuscular blocking agents.

Results

Data from 115 non-cardiac patients were analysed, of whom 53 had moderate-to-severe paediatric acute respiratory distress syndrome (PARDS). Sixteen patients (13.9%) died. Frequencies≥ 8 Hz and high ∆P_proximal were achieved in all patients irrespective of age or PARDS severity. Patients with severe PARDS showed the greatest improvement in oxygenation. pH and PaCO₂ normalized in all patients. Haemodynamic parameters, cumulative amount of fluid challenges, and daily fluid balance did not deteriorate after transitioning to HFOV in any age or PARDS severity group. We observed a transient increase neuromuscular blocking agent use after switching to HFOV, but there was no increase in the daily cumulative amount of continuous midazolam or morphine in any age or PARDS severity group. No patients experienced clinically apparent barotrauma.

Conclusions

This is the first study reporting the feasibility of an alternative, individualized, physiology-based open-lung HFOV strategy targeting high F and high ∆P_proximal. No adverse effects were observed with this strategy. Our findings warrant further systematic evaluation.

Admission, discharge and triage guidelines for paediatric intensive care units in Spain

A paediatric intensive care unit (PICU) is a separate physical facility or unit specifically designed for the treatment of paediatric patients who, because of the severity of illness or other life-threatening conditions, require comprehensive and continuous inten-sive care by a medical team with special skills in paediatric intensive care medicine. Timely and personal intervention in intensive care reduces mortality, reduces length of stay, and decreases cost of care. With the aim of defending the right of the child to receive the highest attainable standard of health and the facilities for the treatment of illness and rehabilitation, as well as ensuring the quality of care and the safety of critically ill paediatric patients, the Spanish Association of Paediatrics (AEP), Spanish Society of Paediatric Intensive Care (SECIP) and Spanish Society of Critical Care (SEMICYUC) have approved the guidelines for the admission, discharge and triage for Spanish PICUs. By using these guidelines, the performance of Spanish paediatric intensive care units can be optimised and paediatric patients can receive the appropriate level of care for their clinical condition.

Acute respiratory distress syndrome

The acute respiratory distress syndrome (ARDS) is a common cause of respiratory failure in critically ill patients and is defined by the acute onset of noncardiogenic pulmonary oedema, hypoxaemia and the need for mechanical ventilation. ARDS occurs most often in the setting of pneumonia, sepsis, aspiration of gastric contents or severe trauma and is present in ~10% of all patients in intensive care units worldwide. Despite some improvements, mortality remains high at 30-40% in most studies. Pathological specimens from patients with ARDS frequently reveal diffuse alveolar damage, and laboratory studies have demonstrated both alveolar epithelial and lung endothelial injury, resulting in accumulation of protein-rich inflammatory oedematous fluid in the alveolar space. Diagnosis is based on consensus syndromic criteria, with modifications for under-resourced settings and in paediatric patients. Treatment focuses on lung-protective ventilation; no specific pharmacotherapies have been identified. Long-term outcomes of patients with ARDS are increasingly recognized as important research targets, as many patients survive ARDS only to have ongoing functional and/or psychological sequelae. Future directions include efforts to facilitate earlier recognition of ARDS, identifying responsive subsets of patients and ongoing efforts to understand fundamental mechanisms of lung injury to design specific treatments.