Early Right Ventricular Systolic Dysfunction and Pulmonary Hypertension Are Associated With Worse Outcomes in Pediatric Acute Respiratory Distress Syndrome

Extubated, Rehabilitation-Focused Extracorporeal Membrane Oxygenation for Pediatric Coronavirus Disease 2019: A Case Series

During the coronavirus 2019 (COVID-19) pandemic, children suffered severe lung injury resulting in acute respiratory distress syndrome requiring support with extracorporeal membrane oxygenation (ECMO). In this case series, we described our center's experience employing a rehabilitation-focused ECMO strategy including extubation during ECMO support in four pediatric patients with acute COVID-19 pneumonia hospitalized from September 2021 to January 2022. All four patients tolerated extubation within 30 days of ECMO initiation and achieved mobility while on ECMO support. Duration of ECMO support was 35-152 days and hospital lengths of stay were 52-167 days. Three of four patients survived. Two of three survivors had normal functional status at discharge except for ongoing respiratory support. The third survivor had significant motor deficits due to critical illness polyneuropathy and was supported with daytime oxygen and nocturnal noninvasive support. Overall, these patients demonstrated good outcomes and tolerance of a rehabilitation-focused ECMO strategy.

New Right Ventricular Dysfunction in Pediatric Acute Respiratory Distress Syndrome on Venovenous Extracorporeal Membrane Oxygenation

The development of new right ventricular (RV) dysfunction after cannulation to venovenous (VV) extracorporeal membrane oxygenation (ECMO) and its association with worse outcomes is increasingly recognized in adult patients, however, no studies have evaluated this phenomenon in pediatric patients. We report results of a single-center retrospective cohort study at a large academic children's hospital. New RV systolic dysfunction was present in 48% (12/25) of pediatric patients on VV ECMO for acute respiratory distress syndrome (ARDS). There was no statistically significant difference in survival, duration of mechanical ventilation, or hospital length of stay between those with and without RV dysfunction. Over half (5/9, 56%) of survivors with RV dysfunction on ECMO had RV dilation or RV hypertrophy on post-ECMO echocardiograms, and in two patients the RV dysfunction persisted for months following decannulation. Cardiac catheterization and autopsy reports suggested that echocardiographic assessment of RV systolic function alone may not be sufficient to diagnose clinically relevant RV injury. This is the first study to report the prevalence of RV dysfunction on VV ECMO for pediatric ARDS. Future multicenter collaboration is needed to create a clinically relevant definition of pediatric "RV injury" and to further evaluate risk factors and outcomes of RV dysfunction.

Quantitative Measures of Right Ventricular Size and Function by Echocardiogram Correlate with Cardiac Catheterization Hemodynamics in Congenital Diaphragmatic Hernia

OBJECTIVE

To evaluate associations between cardiac catheterization (cath) hemodynamics, quantitative measures of right ventricular (RV) function by echocardiogram, and survival in patients with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

This single-center retrospective cohort study enrolled patients with CDH who underwent index cath from 2003 to 2022. Tricuspid annular plane systolic excursion z score, RV fractional area change, RV free wall and global longitudinal strain, left ventricular (LV) eccentricity index, RV/LV ratio, and pulmonary artery acceleration time were measured from preprocedure echocardiograms. Associations between hemodynamic values, echocardiographic measures, and survival were evaluated by Spearman correlation and Wilcoxon rank sum test, respectively.

RESULTS

Fifty-three patients (68% left-sided, 74% liver herniation, 57% extracorporeal membrane oxygenation, 93% survival) underwent cath (39 during index hospitalization, 14 later) including device closure of a patent ductus arteriosus in 5. Most patients (n = 31, 58%) were on pulmonary hypertension treatment at cath, most commonly sildenafil (n = 24, 45%) and/or intravenous treprostinil (n = 16, 30%). Overall, hemodynamics were consistent with precapillary pulmonary hypertension. Pulmonary capillary wedge pressure was >15 mm Hg in 2 patients (4%). Lower fractional area change and worse ventricular strain were associated with higher pulmonary artery pressure while higher LV eccentricity index and higher RV/LV ratio were associated with both higher pulmonary artery pressure and higher pulmonary vascular resistance. Hemodynamics did not differ based on survival status.

CONCLUSIONS

Worse RV dilation and dysfunction by echocardiogram correlate with higher pulmonary artery pressure and pulmonary vascular resistance on cath in this CDH cohort. These measures may represent novel, noninvasive clinical trial targets in this population.

Impaired echocardiographic left ventricular global longitudinal strain after pediatric cardiac arrest children is associated with mortality

BACKGROUND

Global longitudinal strain (GLS) is an echocardiographic method to identify left ventricular (LV) dysfunction after cardiac arrest that is less sensitive to loading conditions. We aimed to identify the frequency of impaired GLS following pediatric cardiac arrest, and its association with hospital mortality.

METHODS

This is a retrospective single-center cohort study of children <18 years of age treated in the pediatric intensive care unit (PICU) after in- or out-of-hospital cardiac arrest (IHCA and OHCA), with echocardiogram performed within 24 hours of initiation of post-arrest PICU care between 2013 and 2020. Patients with congenital heart disease, post-arrest extracorporeal support, or inability to measure GLS were excluded. Echocardiographic LV ejection fraction (EF) and shortening fraction (SF) were abstracted from the chart. GLS was measured post hoc; impaired strain was defined as LV GLS ≥ 2 SD worse than age-dependent normative values. Demographics and pre-arrest, arrest, and post-arrest characteristics were compared between subjects with normal versus impaired GLS. Correlation between GLS, SF and EF were calculated with Pearson comparison. Logistic regression tested the association of GLS with mortality. Area under the receiver operator curve (AUROC) was calculated for discriminative utility of GLS, EF, and SF with mortality.

RESULTS

GLS was measured in 124 subjects; impaired GLS was present in 46 (37.1%). Subjects with impaired GLS were older (median 7.9 vs. 1.9 years, p < 0.001), more likely to have ventricular tachycardia/fibrillation as initial rhythm (19.6% versus 3.8%, p = 0.017) and had higher peak troponin levels in the first 24 hours post-arrest (median 2.5 vs. 0.5, p = 0.002). There were no differences between arrest location or CPR duration by GLS groups. Subjects with impaired GLS compared to normal GLS had lower median EF (42.6% versus 62.3%) and median SF (23.3% versus 36.6%), all p < 0.001, with strong inverse correlation between GLS and EF (rho -0.76, p < 0.001) and SF (rho -0.71, p < 0.001). Patients with impaired GLS had higher rates of mortality (60% vs. 32%, p = 0.009). GLS was associated with mortality when controlling for age and initial rhythm [aOR 1.17 per 1% increase in GLS (95% CI 1.09-1.26), p < 0.001]. GLS, EF and SF had similar discrimination for mortality: GLS AUROC 0.69 (95% CI 0.60-0.79); EF AUROC 0.71 (95% CI 0.58-0.88); SF AUROC 0.71 (95% CI 0.61-0.82), p = 0.101.

CONCLUSIONS

Impaired LV function as measured by GLS after pediatric cardiac arrest is associated with hospital mortality. GLS is a novel complementary metric to traditional post-arrest echocardiography that correlates strongly with EF and SF and is associated with mortality. Future large prospective studies of post-cardiac arrest care should investigate the prognostic utilities of GLS, alongside SF and EF.

Cardiac dysfunction in severe pediatric acute respiratory distress syndrome: the right ventricle in search of the right therapy

Severe acute respiratory distress syndrome in children, or PARDS, carries a high risk of morbidity and mortality that is not fully explained by PARDS severity alone. Right ventricular (RV) dysfunction can be an insidious and often under-recognized complication of severe PARDS that may contribute to its untoward outcomes. Indeed, recent evidence suggest significantly worse outcomes in children who develop RV failure in their course of PARDS. However, in this narrative review, we highlight the dearth of evidence regarding the incidence of and risk factors for PARDS-associated RV dysfunction. While we wish to draw attention to the absence of available evidence that would inform recommendations around surveillance and treatment of RV dysfunction during severe PARDS, we leverage available evidence to glean insights into potentially helpful surveillance strategies and therapeutic approaches.

Alveolar dead space fraction is not associated with early RV systolic dysfunction in pediatric ARDS

PRIMARY HYPOTHESIS

We hypothesized that higher alveolar dead space fraction (AVDSf) at pediatric acute respiratory distress syndrome (PARDS) onset would be associated with right ventricular (RV) systolic dysfunction within the first 24 h of PARDS.

STUDY DESIGN AND METHODS

We performed a retrospective single-center cohort study of PARDS patients with clinically obtained echocardiograms within 24 h. Primary exposure was AVDSf at PARDS onset. Primary outcome was RV systolic dysfunction as defined by RV global longitudinal strain (GLS) (>-18%). Secondary outcomes included pulmonary hypertension (PH) and RV systolic dysfunction as defined by other echocardiogram parameters, and measures of oxygenation. Unadjusted and adjusted logistic and linear regression were used to investigate AVDSf associations with outcomes.

RESULTS

Ninety-one patients were included: median age 6.2 years, 46% female, and 65% with moderate or severe PARDS. Median AVDSf was 0.2 (interquartile range [IQR] 0.0-0.3), 33% had RV dysfunction, and 21% had PH. Unadjusted and adjusted logistic regression showed no association between AVDSf and RV systolic dysfunction or PH by any echocardiographic measure, but unadjusted and adjusted linear regression did show an association between AVDSf and PaO2 /FiO2 .

CONCLUSION

AVDSf at PARDS onset was not associated with RV systolic dysfunction or PH within 24 h but was associated with PaO2 /FiO2 ratio and may be more reflective of pulmonary causes of ventilation-perfusion mismatch. Future investigations should focus on clarifying the clinical utility of AVDSf in relation to existing metrics throughout the course of PARDS.

Monitoring in Pediatric Acute Respiratory Distress Syndrome: From the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

Monitoring is essential to assess changes in the lung condition, to identify heart-lung interactions, and to personalize and improve respiratory support and adjuvant therapies in pediatric acute respiratory distress syndrome (PARDS). The objective of this article is to report the rationale of the revised recommendations/statements on monitoring from the Second Pediatric Acute Lung Injury Consensus Conference (PALICC-2).

DATA SOURCES

MEDLINE (Ovid), Embase (Elsevier), and CINAHL Complete (EBSCOhost).

STUDY SELECTION

We included studies focused on respiratory or cardiovascular monitoring of children less than 18 years old with a diagnosis of PARDS. We excluded studies focused on neonates.

DATA EXTRACTION

Title/abstract review, full-text review, and data extraction using a standardized data collection form.

DATA SYNTHESIS

The Grading of Recommendations Assessment, Development and Evaluation approach was used to identify and summarize evidence and develop recommendations. We identified 342 studies for full-text review. Seventeen good practice statements were generated related to respiratory and cardiovascular monitoring. Four research statements were generated related to respiratory mechanics and imaging monitoring, hemodynamics monitoring, and extubation readiness monitoring.

CONCLUSIONS

PALICC-2 monitoring good practice and research statements were developed to improve the care of patients with PARDS and were based on new knowledge generated in recent years in patients with PARDS, specifically in topics of general monitoring, respiratory system mechanics, gas exchange, weaning considerations, lung imaging, and hemodynamic monitoring.

Pleural and transpulmonary pressures to tailor protective ventilation in children

This review aims to: (1) describe the rationale of pleural (P_PL) and transpulmonary (P_L) pressure measurements in children during mechanical ventilation (MV); (2) discuss its usefulness and limitations as a guide for protective MV; (3) propose future directions for paediatric research. We conducted a scoping review on P_L in critically ill children using PubMed and Embase search engines. We included peer-reviewed studies using oesophageal (P_ES) and P_L measurements in the paediatric intensive care unit (PICU) published until September 2021, and excluded studies in neonates and patients treated with non-invasive ventilation. P_L corresponds to the difference between airway pressure and P_PL Oesophageal manometry allows measurement of P_ES, a good surrogate of P_PL, to estimate P_L directly at the bedside. Lung stress is the P_L, while strain corresponds to the lung deformation induced by the changing volume during insufflation. Lung stress and strain are the main determinants of MV-related injuries with P_L and P_PL being key components. P_L-targeted therapies allow tailoring of MV: (1) Positive end-expiratory pressure (PEEP) titration based on end-expiratory P_L (direct measurement) may be used to avoid lung collapse in the lung surrounding the oesophagus. The clinical benefit of such strategy has not been demonstrated yet. This approach should consider the degree of recruitable lung, and may be limited to patients in which PEEP is set to achieve an end-expiratory P_L value close to zero; (2) Protective ventilation based on end-inspiratory P_L (derived from the ratio of lung and respiratory system elastances), might be used to limit overdistention and volutrauma by targeting lung stress values < 20-25 cmH₂O; (3) P_PL may be set to target a physiological respiratory effort in order to avoid both self-induced lung injury and ventilator-induced diaphragm dysfunction; (4) P_PL or P_L measurements may contribute to a better understanding of cardiopulmonary interactions. The growing cardiorespiratory system makes children theoretically more susceptible to atelectrauma, myotrauma and right ventricle failure. In children with acute respiratory distress, P_PL and P_L measurements may help to characterise how changes in PEEP affect P_PL and potentially haemodynamics. In the PICU, P_PL measurement to estimate respiratory effort is useful during weaning and ventilator liberation. Finally, the use of P_PL tracings may improve the detection of patient ventilator asynchronies, which are frequent in children. Despite these numerous theoritcal benefits in children, P_ES measurement is rarely performed in routine paediatric practice. While the lack of robust clincal data partially explains this observation, important limitations of the existing methods to estimate P_PL in children, such as their invasiveness and technical limitations, associated with the lack of reference values for lung and chest wall elastances may also play a role. P_PL and P_L monitoring have numerous potential clinical applications in the PICU to tailor protective MV, but its usefulness is counterbalanced by technical limitations. Paediatric evidence seems currently too weak to consider oesophageal manometry as a routine respiratory monitoring. The development and validation of a noninvasive estimation of P_L and multimodal respiratory monitoring may be worth to be evaluated in the future.

Factors associated with discontinuation of pulmonary vasodilator therapy in children with bronchopulmonary dysplasia-associated pulmonary hypertension

OBJECTIVE

To evaluate factors associated with discontinuation of pulmonary vasodilator therapy in bronchopulmonary dysplasia-related pulmonary hypertension (BPD-PH).

STUDY DESIGN

Retrospective study of neonatal, echocardiographic, and cardiac catheterization data in 121 infants with BPD-PH discharged on pulmonary vasodilator therapy from 2009-2020 and followed into childhood.

RESULT

After median 4.4 years, medications were discontinued in 58%. Those in whom medications were discontinued had fewer days of invasive support, less severe BPD, lower incidence of PDA closure or cardiac catheterization, and higher incidence of fundoplication or tracheostomy decannulation (p < 0.05). On multivariable analysis, likelihood of medication discontinuation was lower with longer period of invasive respiratory support [HR 0.95 (CI:0.91-0.99), p = 0.01] and worse RV dilation on pre-discharge echocardiogram [HR 0.13 (CI:0.03-0.70), p = 0.017]. In those with tracheostomy, likelihood of medication discontinuation was higher with decannulation [HR 10.78 (CI:1.98-58.59), p < 0.001].

CONCLUSION

In BPD-PH, childhood discontinuation of pulmonary vasodilator therapy is associated with markers of disease severity.

Right Ventricular Strain, Brain Natriuretic Peptide, and Mortality in Congenital Diaphragmatic Hernia

Rationale: Brain-type natriuretic peptide (BNP) correlates with pulmonary hypertension as demonstrated by echocardiogram in congenital diaphragmatic hernia (CDH); however, its association with right ventricular (RV) function and mortality is unknown.Objectives: To characterize the relationships between echocardiogram-derived RV strain, BNP, and mortality in diaphragmatic hernia.Methods: We performed a single-center retrospective cohort study of infants with CDH and at least one BNP-echocardiogram pair within a 24-hour period. RV global longitudinal strain (GLS) and free-wall strain (FWS) were measured on existing echocardiograms. Associations among strain, BNP, and mortality were tested using mixed-effect linear and logistic regression models. Survival analysis was stratified by BNP and strain abnormalities.Results: There were 220 infants with 460 BNP-echocardiogram pairs obtained preoperatively (n = 237), ≤1 week postoperatively (n = 35), and >1 week postoperatively ("recovery"; n = 188). Strain improved after repair (P < 0.0001 for all periods). Higher BNP level was associated with worse strain in recovery but not before or immediately after operation (estimate [95% confidence interval] for recovery: GLS, 1.03 [0.50-1.57]; P = 0.0003; FWS, 0.62 [0.01-1.22]; P = 0.047). BNP and strain abnormalities were associated with an extracorporeal-membrane oxygenation requirement. Higher BNP level in recovery was associated with greater mortality (odds ratio, 11.2 [1.2-571.3]; P = 0.02). Abnormal strain in recovery had high sensitivity for detection of mortality (100% for GLS; 100% for FWS) but had low specificity for detection of mortality (28% for GLS; 48% for FWS).Conclusions: Persistent RV dysfunction after CDH repair may be detected by a high BNP level and abnormal RV strain.

Paediatrics: how to manage acute respiratory distress syndrome

Background

Acute respiratory distress syndrome (ARDS) is a significant cause of mortality and morbidity amongst critically ill children. The purpose of this narrative review is to provide an up-to-date review on the evaluation and management of paediatric ARDS (PARDS).

Methods

A PubMed search was performed with Clinical Queries using the key term "acute respiratory distress syndrome". The search strategy included clinical trials, meta-analyses, randomized controlled trials, observational studies and reviews. Google, Wikipedia and UpToDate were also searched to enrich the review. The search was restricted to the English literature and children.

Discussion

Non-invasive positive pressure ventilation, lung-protective ventilation strategies, conservative fluid management and adequate nutritional support all have proven efficacy in the management of PARDS. The Pediatric Acute Lung Injury Consensus Conference recommends the use of corticosteroids, high-frequency oscillation ventilation and inhaled nitric oxide in selected scenarios. Partial liquid ventilation and surfactant are not considered efficacious based on evidence from clinical trials.

Conclusion

PARDS is a serious but relatively rare cause of admission into the paediatric intensive care unit and is associated with high mortality. Non-invasive positive pressure ventilation, lung-protective ventilation strategies, conservative fluid management and adequate nutrition are advocated. As there has been a lack of progress in the management of PARDS in recent years, further well-designed, large-scale, randomized controlled trials in this field are urgently needed.

Preoperative echocardiographic parameters predict primary graft dysfunction following pediatric lung transplantation

The importance of preoperative cardiac function in pediatric lung transplantation is unknown. We hypothesized that worse preoperative right ventricular (RV) systolic and worse left ventricular (LV) diastolic function would be associated with a higher risk of primary graft dysfunction grade 3 (PGD 3) between 48 and 72 hours. We performed a single center, retrospective pilot study of children (<18 years) who had echocardiograms <1 year prior to lung transplantation between 2006 and 2019. Conventional and strain echocardiography parameters were measured, and PGD was graded. Area under the receiver operating characteristic (AUROC) curves and logistic regression were performed. Forty-one patients were included; 14 (34%) developed PGD 3 and were more likely to have pulmonary hypertension (PH) as the indication for transplant (P = .005). PGD 3 patients had worse RV global longitudinal strain (P = .01), RV free wall strain (FWS) (P = .003), RV fractional area change (P = .005), E/e' (P = .01) and lateral e' velocity (P = .004) but not tricuspid annular plane systolic excursion (P = .61). RV FWS (AUROC 0.79, 95% CI 0.62-0.95) and lateral e' velocity (AUROC 0.87, 95% CI 0.68-1.00) best discriminated PGD 3 development and showed the strongest association with PGD 3 (RV FWS OR 3.87 [95% CI 1.59-9.43], P = .003; lateral e' velocity OR 0.10 [95% CI 0.01-0.70], P = .02). These associations remained when separately adjusting for age, weight, primary PH diagnosis, ischemic time, and bypass time. In this pilot study, worse preoperative RV systolic and worse LV diastolic function were associated with PGD 3 and may be modifiable recipient risk factors in pediatric lung transplantation.

Echocardiographic strain analysis reflects impaired ventricular function in youth with pediatric-onset systemic lupus erythematosus

BACKGROUND

Strain analysis with speckle-tracking echocardiography shows promise as a screening tool for silent myocardial dysfunction in pediatric-onset systemic lupus erythematosus (pSLE). We compared left ventricular (LV) systolic deformation (measured by strain) in children and adolescents with pSLE to controls, and assessed the relationship between strain, disease activity, and other noninvasive measures of cardiovascular health.

METHODS

Twenty pSLE subjects ages 9-21 underwent comprehensive cardiovascular testing, including 2D speckle-tracking echocardiography, ambulatory blood pressure monitoring (ABPM), peripheral endothelial function testing, pulse wave velocity and analysis, and carotid ultrasound. Longitudinal apical-4 chamber (LS_A4C ) and midpoint circumferential strain (CS_mid ) were compared to that of 70 healthy controls using multivariable linear regression. Among pSLE subjects, Pearson correlation coefficients were calculated to evaluate relationships between global longitudinal or circumferential strain and other measures of cardiovascular health.

RESULTS

Average SLE disease duration was 3.2 years (standard deviation [SD] 2.1). 2/20 pSLE subjects had persistent disease activity, and only one met criteria for hypertension by ABPM. LS_A4C was significantly reduced in pSLE subjects compared to controls (mean -18.3 [SD 3.2] vs -21.8% [SD 2.2], P-value <.001). There was no significant difference in CS_mid (-24.8 [SD 3.7] vs -25.7% [SD 3.4], P = .29). Among pSLE subjects, decreased nocturnal blood pressure dipping on ABPM was associated with reduced global circumferential strain (r -0.59, P = .01).

CONCLUSIONS

Longitudinal myocardial deformation is impaired in pSLE patients despite clinical remission and may represent early myocardial damage. Strain analysis should be considered in addition to standard echocardiographic assessment during follow-up of patients with pSLE.

Inhaled Nitric Oxide Use in Pediatric Hypoxemic Respiratory Failure

OBJECTIVES

To characterize contemporary use of inhaled nitric oxide in pediatric acute respiratory failure and to assess relationships between clinical variables and outcomes. We sought to study the relationship of inhaled nitric oxide response to patient characteristics including right ventricular dysfunction and clinician responsiveness to improved oxygenation. We hypothesize that prompt clinician responsiveness to minimize hyperoxia would be associated with improved outcomes.

DESIGN

An observational cohort study.

SETTING

Eight sites of the Collaborative Pediatric Critical Care Research Network.

PATIENTS

One hundred fifty-one patients who received inhaled nitric oxide for a primary respiratory indication.

MEASUREMENTS AND MAIN RESULTS

Clinical data were abstracted from the medical record beginning at inhaled nitric oxide initiation and continuing until the earliest of 28 days, ICU discharge, or death. Ventilator-free days, oxygenation index, and Functional Status Scale were calculated. Echocardiographic reports were abstracted assessing for pulmonary hypertension, right ventricular dysfunction, and other cardiovascular parameters. Clinician responsiveness to improved oxygenation was determined. One hundred thirty patients (86%) who received inhaled nitric oxide had improved oxygenation by 24 hours. PICU mortality was 29.8%, while a new morbidity was identified in 19.8% of survivors. Among patients who had echocardiograms, 27.9% had evidence of pulmonary hypertension, 23.1% had right ventricular systolic dysfunction, and 22.1% had an atrial communication. Moderate or severe right ventricular dysfunction was associated with higher mortality. Clinicians responded to an improvement in oxygenation by decreasing FIO2 to less than 0.6 within 24 hours in 71% of patients. Timely clinician responsiveness to improved oxygenation with inhaled nitric oxide was associated with more ventilator-free days but not less cardiac arrests, mortality, or additional morbidity.

CONCLUSIONS

Clinician responsiveness to improved oxygenation was associated with less ventilator days. Algorithms to standardize ventilator management may improve signal to noise ratios in future trials enabling better assessment of the effect of inhaled nitric oxide on patient outcomes. Additionally, confining studies to more selective patient populations such as those with right ventricular dysfunction may be required.

Prevalence and Outcomes of Pediatric In-Hospital Cardiac Arrest Associated With Pulmonary Hypertension

OBJECTIVES

In adult in-hospital cardiac arrest, pulmonary hypertension is associated with worse outcomes, but pulmonary hypertension-associated in-hospital cardiac arrest has not been well studied in children. The objective of this study was to determine the prevalence of pulmonary hypertension among children with in-hospital cardiac arrest and its impact on outcomes.

DESIGN

Retrospective single-center cohort study.

SETTING

PICU of a quaternary care, academic children's hospital.

PATIENTS

Children (<18 yr old) receiving greater than or equal to 1 minute of cardiopulmonary resuscitation (cardiopulmonary resuscitation) for an index in-hospital cardiac arrest with an echocardiogram in the 48 hours preceding in-hospital cardiac arrest, excluding those with cyanotic congenital heart disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 284 in-hospital cardiac arrest subjects, 57 (20%) had evaluable echocardiograms, which were analyzed by a cardiologist blinded to patient characteristics. Pulmonary hypertension was present in 20 of 57 (35%); nine of 20 (45%) had no prior pulmonary hypertension history. Children with pulmonary hypertension had worse right ventricular systolic function, measured by fractional area change (p = 0.005) and right ventricular global longitudinal strain (p = 0.046); more right ventricular dilation (p = 0.010); and better left ventricular systolic function (p = 0.001). Children with pulmonary hypertension were more likely to have abnormal baseline functional status and a history of chronic lung disease or acyanotic congenital heart disease and less likely to have sepsis or acute kidney injury. Children with pulmonary hypertension were more likely to have an initial rhythm of pulseless electrical activity or asystole and were more frequently treated with inhaled nitric oxide (80% vs 32%; p < 0.001) at the time of cardiopulmonary resuscitation. On multivariable analysis, pulmonary hypertension was not associated with event survival (14/20 [70%] vs 24/37 [65%]; adjusted odds ratio, 1.30 [CI95, 0.25-6.69]; p = 0.77) or survival to discharge (8/20 [40%] vs 10/37 [27%]; adjusted odds ratio, 1.17 [CI95, 0.22-6.44]; p = 0.85).

CONCLUSIONS

Pulmonary hypertension physiology preceding pediatric in-hospital cardiac arrest may be more common than previously described. Among this cohort with a high frequency of inhaled nitric oxide treatment during cardiopulmonary resuscitation, pulmonary hypertension was not associated with survival outcomes.

Cardiac Dysfunction Identified by Strain Echocardiography Is Associated With Illness Severity in Pediatric Sepsis

OBJECTIVES

Sepsis-induced myocardial dysfunction has been associated with illness severity and mortality in pediatrics. Although early sepsis-induced myocardial dysfunction diagnosis could aid in hemodynamic management, current echocardiographic metrics for assessing biventricular function are limited in detecting early impairment. Strain echocardiography is a validated quantitative measure that can detect subtle perturbations in left ventricular and right ventricular function. This investigation evaluates the utility of strain echocardiography in pediatric sepsis and compares with to conventional methods.

DESIGN

Retrospective, observational study comparing left ventricular and right ventricular strain. Strain was compared with ejection fraction and fractional shortening and established sepsis severity of illness markers.

SETTING

Tertiary care medical-surgical PICU from July 2013 to January 2018.

PATIENTS

Seventy-nine septic children and 28 healthy controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Compared with healthy controls, patients with severe sepsis demonstrated abnormal left ventricular strain (left ventricular longitudinal strain: -13.0% ± 0.72; p = 0.04 and left ventricular circumferential strain: -16.5% ± 0.99; p = 0.046) and right ventricular (right ventricular longitudinal strain = -14.3% ± 6.3; p < 0.01) despite normal fractional shortening (36.0% ± 1.6 vs 38.1% ± 1.1; p = 0.5129) and ejection fraction (60.7% ± 2.2 vs 65.3% ± 1.5; p = 0.33). There was significant association between depressed left ventricular longitudinal strain and increased Vasotrope-Inotrope Score (r = 0.52; p = 0.034). Worsening left ventricular circumferential strain was correlated with higher lactate (r = 0.31; p = 0.03) and higher Pediatric Risk of Mortality-III score (r = 0.39; p < 0.01). Depressed right ventricular longitudinal strain was associated with elevated pediatric multiple organ dysfunction score (r = 0.44; p < 0.01) CONCLUSIONS:: Compared with healthy children, pediatric septic patients demonstrated abnormal left ventricular and right ventricular strain concerning for early signs of cardiac dysfunction. This was despite having normal ejection fraction and fractional shortening. Abnormal strain was associated with abnormal severity of illness markers. Strain echocardiography may have utility as an early indicator of sepsis-induced myocardial dysfunction in pediatric sepsis.

New or Persistent Right Ventricular Systolic Dysfunction Is Associated With Worse Outcomes in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

The trajectory and importance of right ventricular systolic function and pulmonary hypertension during the course of pediatric acute respiratory distress syndrome are unknown. We hypothesized that new or persistent right ventricular systolic dysfunction and pulmonary hypertension would be associated with worse patient outcomes.

DESIGN

Retrospective, single-center cohort study.

SETTING

Tertiary care, university-affiliated PICU.

PATIENTS

Children who had at least two echocardiograms less than 8 days following pediatric acute respiratory distress syndrome diagnosis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Between July 1, 2012, and April 30, 2018, 74 children met inclusion criteria. The first echocardiogram was performed a median of 0.61 days (interquartile range, 0.36-0.94 d) and the second echocardiogram was performed a median of 2.57 days (interquartile range, 1.67-3.63 d) after pediatric acute respiratory distress syndrome diagnosis. Univariate analyses showed that new or persistent right ventricular systolic dysfunction as defined by global longitudinal strain or free wall strain was associated with a greater number of ICU days in survivors (global longitudinal strain p = 0.04, free wall strain p = 0.04), lower ventilator-free days at 28 days (global longitudinal strain p = 0.03, free wall strain p = 0.01), and higher rate of PICU death (global longitudinal strain p = 0.046, free wall strain p = 0.01). Mixed-effects multivariate modeling showed that right ventricular global longitudinal strain and right ventricular fractional area change stayed relatively constant over the course of the first 8 days in nonsurvivors and that there was a linear improvement in global longitudinal strain (p = 0.037) and fractional area change (p = 0.05) in survivors. Worsening right ventricular dysfunction at the time of repeat echocardiogram as defined by global longitudinal strain and free wall strain were independently associated with decreased probability of extubation (subdistribution hazard ratio, 0.30 [0.14-0.67]; p = 0.003 and subdistribution hazard ratio, 0.47 [0.23-0.98]; p = 0.043, respectively). In univariate and multivariate analyses, pulmonary hypertension had no significant associations with outcomes in his cohort.

CONCLUSIONS

New or persistent right ventricular systolic dysfunction over the first week following pediatric acute respiratory distress syndrome onset is associated with worse patient outcomes, including decreased probability of extubation and higher PICU mortality.

Pertinent clinical outcomes in pediatric survivors of pediatric acute respiratory distress syndrome (PARDS): a narrative review

The objectives of this review are to describe the limitations of commonly used clinical outcomes [e.g., mortality, ventilation parameters, need for extracorporeal membrane oxygenation (ECMO), pediatric intensive care unit (PICU) and hospital length of stay (LOS)] in pediatric acute respiratory distress syndrome (PARDS) studies; and to explore other pertinent clinical outcomes that pediatric critical care practitioners should consider in future clinical practice and research studies. These include long-term pulmonary function, risk of pulmonary hypertension (PHT), nutrition status and growth, PICU-acquired weakness, neurological outcomes and neurocognitive development, functional status, health-related quality of life (HRQOL)], health-care costs, caregiver and family stress. PubMed was searched using the following keywords or medical subject headings (MESH): "acute lung injury (ALI)", "acute respiratory distress syndrome (ARDS)", "pediatric acute respiratory distress syndrome (PARDS)", "acute hypoxemia respiratory failure", "outcomes", "pediatric intensive care unit (PICU)", "lung function", "pulmonary hypertension", "growth", "nutrition', "steroid", "PICU-acquired weakness", "functional status scale", "neurocognitive", "psychology", "health-care expenditure", and "HRQOL". The concept of contemporary measure outcomes was adapted from adult ARDS long-term outcome studies. Articles were initially searched from existing PARDS articles pool. If the relevant measure outcomes were not found, where appropriate, we considered studies from non-ARDS patients within the PICU in whom these outcomes were studied. Long-term outcomes in survivors of PARDS were not follow-up in majority of pediatric studies regardless of whether the new or old definitions of ARDS in children were used. Relevant studies were scarce, and the number of participants was small. As such, available studies were not able to provide conclusive answers to most of our clinical queries. There remains a paucity of data on contemporary clinical outcomes in PARDS studies. In addition to the current commonly used outcomes, clinical researchers and investigators should consider examining these contemporary outcome measures in PARDS studies in the future.

EXPRESS: Statement on imaging and pulmonary hypertension from the Pulmonary Vascular Research Institute (PVRI)

Pulmonary hypertension (PH) is highly heterogeneous and despite treatment advances it remains a life-shortening condition. There have been significant advances in imaging technologies, but despite evidence of their potential clinical utility, practice remains variable, dependent in part on imaging availability and expertise. This statement summarizes current and emerging imaging modalities and their potential role in the diagnosis and assessment of suspected PH. It also includes a review of commonly encountered clinical and radiological scenarios, and imaging and modeling-based biomarkers. An expert panel was formed including clinicians, radiologists, imaging scientists, and computational modelers. Section editors generated a series of summary statements based on a review of the literature and professional experience and, following consensus review, a diagnostic algorithm and 55 statements were agreed. The diagnostic algorithm and summary statements emphasize the key role and added value of imaging in the diagnosis and assessment of PH and highlight areas requiring further research.

Sepsis and Pediatric Acute Respiratory Distress Syndrome

The epidemiology of the acute respiratory distress syndrome (ARDS) in pediatric sepsis is poorly defined. With significant data extrapolated from adult studies in sepsis and ARDS, sometimes with uncertain applicability, better pediatric-specific guidelines and dedicated investigations are warranted. The recent publication of a consensus definition for pediatric ARDS (PARDS) is the first step in addressing this knowledge gap. The aim of this review is to frame our current understanding of PARDS as it relates to pediatric sepsis, encompassing epidemiology, pathophysiology, and management. We argue that addressing the role of PARDS in pediatric sepsis requires significant attention to details with respect to how PARDS and sepsis are defined to accurately describe their epidemiology, natural history, and outcomes. Finally, we highlight certain aspects of PARDS management as they relate to the septic child and offer suggestion for future directions in this field.