Acute respiratory distress syndrome in pediatric intensive care unit

Pediatric Acute Respiratory Distress Syndrome in India: Time for Collaborative Study?

How to cite this article: Solomon R. Pediatric Acute Respiratory Distress Syndrome in India: Time for Collaborative Study? Indian J Crit Care Med 2022;26(8):896-897.

Role of Sildenafil in Management of Pediatric Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) has high mortality and multiple therapeutic strategies have been used to improve the outcome. Inhaled nitric oxide (INO), a pulmonary vasodilator, is used to improve oxygenation. This study was conducted to determine the role of sildenafil, an oral vasodilator, to improve oxygenation and mortality in pediatric ARDS (PARDS). The prevalence of pulmonary hypertension in PARDS was studied as well. Inclusion criteria included children (1–18 years) with ARDS requiring invasive ventilation admitted to the pediatric intensive care unit of a teaching hospital in Northern India over a 1-year period of time. Thirty-five patients met the inclusion criteria. Cardiologist performed a detailed echocardiogram to determine pulmonary arterial pressure (PAP). Patients with persistent hypoxemia were started on oral sildenafil. The majority (77%) patients had a primary pulmonary etiology of PARDS. Elevated PAP (>25 mm Hg) was detected in 54.3% patients at admission. Sildenafil was given to 20 patients who had severe and persistent hypoxemia. Oxygenation improved in most patients after the first dose with statistically significant improvement in PaO2/FiO2 ratios at both 12 and 24 hours following initiation of therapeutic dosing of sildenafil. Improvement in oxygenation occurred irrespective of initial PAP. Outcomes included a total of 57.1% patients discharged, 28.6% discharged against medical advice (DAMA), and a 14.3% mortality rate. Mortality was related to the severity of PARDS and not the use of sildenafil. This is the first study to determine the effect of sildenafil in PARDS. Sildenafil led to improvement in oxygenation in nearly all the cases without affecting mortality. Due to unavailability of INO in most centers of developing countries, sildenafil may be considered as an inexpensive alternative in cases of persistent hypoxemia in PARDS. We recommend additional randomized controlled trials to confirm the effect of sildenafil in PARDS as determined in this study.

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.

Performance of PRISM III, PELOD-2, and P-MODS Scores in Two Pediatric Intensive Care Units in China

Objective: The performances of the pediatric risk of mortality score III (PRISM III), pediatric logistic organ dysfunction score-2 (PELOD-2), and pediatric multiple organ dysfunction score (P-MODS) in Chinese patients are unclear. This study aimed to assess the performances of these scores in predicting mortality in critically ill pediatric patients. Methods: This retrospective observational study was conducted at two tertiary-care PICUs of teaching hospitals in China. A total of 1,253 critically ill pediatric patients admitted to the two Pediatric Intensive Care Units (PICUs) of the First Affiliated Hospital, Sun Yat-Sen University from August 2014 to December 2019 and Shen-Zhen Children's Hospital from January 2019 to December 2019 were analyzed. The indexes of discrimination and calibration were applied to evaluate score performance for the three models (PRISM III, PELOD-2, and P-MODS scores). The receiver operating characteristic (ROC) curve was plotted, and the efficiency of PRISM III, PELOD-2, and P-MODS in predicting death were evaluated by the area under ROC curve (AUC). Hosmer-Lemeshow goodness-of-fit test was used to evaluate the degree of fitting between the mortality predictions of each scoring system and the actual mortality. Results: A total of 1,253 pediatric patients were eventually enrolled in this study (median age, 38 months; overall mortality rate, 8.9%; median length of PICU stay, 8 days). Compared to the survival group, the non-survival group showed significantly higher PRISM III, PELOD-2, and P-MODS scores [PRISM III: 18 (12, 23) vs. 11 (0, 16); PELOD-2, 8 (4, 10) vs. 4 (0, 6); and P-MODS: 5 (4, 9) vs. 3 (0, 4), all P < 0.001]. ROC curve analysis showed that the AUCs of PRISM III, PELOD-2, and P-MODS for predicting the death of critically ill children were 0.858, 0.721, and 0.596, respectively. Furthermore, in the Hosmer-Lemeshow goodness-of-fit test, PRISM III and PELOD-2 showed the better calibration between predicted mortality and observed mortality (PRISM III: χ² = 5.667, P = 0.368; PELOD-2: χ² = 9.582, P = 0.276; P-MODS: χ² = 12.449, P = 0.015). Conclusions: PRISM III and PELOD-2 can discriminate well between survivors and non-survivors. PRISM III and PELOD-2 showed the better calibration between predicted and observed mortality, while P-MODS showed poor calibration.

Frequency of Pediatric Acute Respiratory Distress Syndrome Based on Oxygen Saturation Index in Pediatric Intensive Care Unit of a Developing Country

Objectives

To determine the frequency of pediatric acute respiratory distress syndrome based on oxygen saturation index in pediatric intensive care unit of a developing country.

Methods

We conducted a retrospective study of all children admitted in pediatric intensive care unit (PICU) of Aga Khan University Hospital, Karachi from July 2017 to June 2018 with respiratory rate >40 breaths/minute, shortness of breath, and bluish discoloration of skin and mucous membranes. The diagnosis of acute respiratory distress syndrome (ARDS) was made on the basis of standard operational definitions as mentioned (fulfilling criteria for ARDS).

Results

During the one-year study period 150 patients with age range of one month to 16 years were admitted fulfilling the inclusion criteria. Mean age was 38.27 ± 53.13 months, and 92 (61.33%) were male with male to female ratio of 1.6:1. Mean duration of symptoms was 1.23 ± 0.42 days. Frequency of pediatric acute respiratory distress syndrome using oxygen saturation index admitted in a pediatric ICU was 23 (15.33%) patients.

Conclusion

This study has shown that the frequency of pediatric acute respiratory distress syndrome is quite high.

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.

Burden of respiratory illnesses in pediatric intensive care unit and predictors of mortality: Experience from a low resource country

INTRODUCTION AND OBJECTIVES

Acute respiratory infections (ARI), a major cause of childhood mortality and morbidity, place substantial burden on health services worldwide. Due to scarce data regarding respiratory illnesses requiring Pediatric intensive care unit (PICU) admissions (especially in low income/developing countries), we studied the burden of respiratory illnesses in the PICU and the risk factors contributing to mortality.

METHODS

This prospective observational study was conducted over 18 months. Children (aged 1 month to 12 years) admitted to the PICU for acute respiratory/cardiorespiratory illnesses were enrolled. Demographic and clinical details of the study population were recorded and tabulated. Risk factors contributing to mortality (severity of illness [PRISM III score], diagnosis/etiology, need for mechanical ventilation, immunocompromised status, malnutrition, and length of stay [LOS]) were analyzed (using the χ² test or Fischer Exact test).

RESULTS

Two hundred and ninety-three children were enrolled (median age: 5 months; range, 1-132 months; male/female: 181/112). Mean LOS in PICU was 5.25 ± 5.48 days and mean length of hospital stay of 14.82 ± 13.35 days. Mechanical ventilation was required in 62.8% cases. Pneumonia contributed to 66.89% of respiratory admissions and 91% of mortality. Ninety patients (30.7%) died; mortality being higher in cardiorespiratory cases (52.7%). PRISM III score and shock (respiratory cases) and age below 1 year (cardiorespiratory group) were significantly associated with higher mortality ( P < 0.05).

CONCLUSIONS

Respiratory illnesses are a significant contributor to PICU admissions and are associated with significant mortality risk in presence of high PRISM III score and shock (respiratory group); and age below 1 year (cardiorespiratory group).

Exogenous surfactant and alveolar recruitment in the treatment of the acute respiratory distress syndrome

OBJECTIVE

To investigate the effect of alveolar recruitment combined with surfactant administration on children with acute respiratory distress syndrome (ARDS).

MATERIAL AND METHODS

A prospective, randomized, controlled and sequential study was carried out. Group A (16 children) was treated with both the alveolar recruitment manoeuvres (ARM) and the administration of the surfactant every 8 h for 3 days; group B (15) received the usual treatment only. The alveolar recruitment was carried out by increasing positive end-expiratory pressure 2 by 2 cm H₂ O to improve the transcutaneous oxygen saturation values up to 88% and 90%. Demographic data, gasometric and ventilator parameters, chest radiography and 28-day mortality were evaluated.

RESULTS

There were no significant differences in baseline characteristics between groups. An hour after treatment, significant differences (P < 0.001) were observed in transcutaneous oxygen saturation (SaO₂ ; Group A: 94.1%, Group B: 89.9%), PaO₂ /FiO₂ (212.7 and 126.4) and oxygenation index (OI; 11.4 and 18.5). After 8 h, the differences in SaO₂ (Group A: 94.6%, Group B: 90.3%), PaO₂ /FiO₂ (225.8 and 126.9) and OI (10.8 and 18.4) were also significant (P < 0.001). From the fifth dose of the surfactant, the static compliance (P = 0.0034) and radiological images (P = 0.002) were more greatly improved in group A than in group B. Survival was significantly higher in group A (81.3%) than in group B (26.7%) (P = 0.006).

CONCLUSIONS

The combined treatment of surfactant administration and ARM resulted in a better oxygenation and survival in children with ARDS than when only recruitment was used.

High-dose Oral Ambroxol for Early Treatment of Pulmonary Acute Respiratory Distress Syndrome: an Exploratory, Randomized, Controlled Pilot Trial

OBJECTIVE

To evaluate efficacy of high-dose oral ambroxol in acute respiratory distress syndrome (ARDS) with respect to ventilator-free days (VFD).

DESIGN

Prospective, randomized, placebo-controlled, blinded pilot trial.

PATIENTS

Sixty-six mechanically ventilated patients (1 month to 12 years) with ARDS who were hand-ventilated for <24 hr before pediatric intensive care unit admission.

INTERVENTIONS

Patients randomized to oral ambroxol (40 mg/kg/day, in four divided doses) (n = 32) or placebo (n = 34) until 10 days, extubation or death whichever is earlier.

MEASUREMENTS AND MAIN RESULTS

Majority (91%) had pneumonia and bronchiolitis. Two study groups were similar in baseline characteristics. Mean partial pressure of arterial oxygen/fraction of inspired oxygen and oxygenation index were >175 and <10, respectively, with no difference in the two study groups. VFD were similar in the two study groups. Overall mortality was 26%. No adverse events were noted with ambroxol.

CONCLUSIONS

Among ventilated pulmonary ARDS patients with oxygenation index of <10, mortality was 26%. Ambroxol did not improve VFD. Study with higher and more frequently administered doses of ambroxol in larger sample is suggested after having generated relevant pharmacokinetic data among critically ill children.

The outcomes of children with pediatric acute respiratory distress syndrome: proceedings from the Pediatric Acute Lung Injury Consensus Conference

OBJECTIVE

To provide additional details and evidence behind the recommendations for outcomes assessment of patients with pediatric acute respiratory distress syndrome from the Pediatric Acute Lung Injury Consensus Conference.

DESIGN

Consensus conference of experts in pediatric acute lung injury.

METHODS

A panel of 27 experts met over the course of 2 years to develop a taxonomy to define pediatric acute respiratory distress syndrome and to make recommendations regarding treatment and research priorities. The outcomes subgroup comprised four experts. When published data were lacking, a modified Delphi approach emphasizing strong professional agreement was used.

RESULTS

The Pediatric Acute Lung Injury Consensus Conference experts developed and voted on a total of 151 recommendations addressing the topics related to pediatric acute respiratory distress syndrome, seven of which related to outcomes after pediatric acute respiratory distress syndrome. All seven recommendations had strong agreement. Children with acute respiratory distress syndrome continue to have a high mortality, specifically, in relation to certain comorbidities and etiologies related to pediatric acute respiratory distress syndrome. Comorbid conditions, such as an immunocompromised state, increase the risk of mortality even further. Likewise, certain etiologies, such as non-pulmonary sepsis, also place children at a higher risk of mortality. Significant long-term effects were reported in adult survivors of acute respiratory distress syndrome: diminished lung function and exercise tolerance, reduced quality of life, and diminished neurocognitive function. Little knowledge of long-term outcomes exists in children who survive pediatric acute respiratory distress syndrome. Characterization of the longer term consequences of pediatric acute respiratory distress syndrome in children is vital to help identify opportunities for improved therapeutic and rehabilitative strategies that will lessen the long-term burden of pediatric acute respiratory distress syndrome and improve the quality of life in children.

CONCLUSIONS

The Consensus Conference developed pediatric-specific recommendations for pediatric acute respiratory distress syndrome regarding outcome measures and future research priorities. These recommendations are intended to promote optimization and consistency of care for children with pediatric acute respiratory distress syndrome and identify areas of uncertainty requiring further investigation.

Tumor necrosis factor (TNF) and lymphotoxin-alpha (LTA) single nucleotide polymorphisms: importance in ARDS in septic pediatric critically ill patients

Accumulating evidence indicates that genetic background influences the outcome of sepsis, which despite medical advances continues to be a major cause of morbidity and mortality. This study aimed to evaluate the influence of SNPs LTA +252A>G, TNF-863C>A and TNF-308G>A on susceptibility to sepsis, acute respiratory distress syndrome (ARDS), septic shock and sepsis mortality. A prospective case-control study was carried out in a Brazilian pediatric intensive care unit and included 490 septic pediatric patients submitted to mechanical ventilation and 610 healthy children. No SNP association was found with respect to sepsis susceptibility. Nevertheless, a haplotype was identified that was protective against sepsis (+252A/-863A/-308G; OR=0.65; p=0.03). We further observed protection against ARDS in TNF-308 GA genotype carriers (OR=0.29; p=0.0006) and -308A allele carriers (OR=0.40; p=0.003). In addition, increased risk for ARDS was detectable with the TNF-863 CA genotype (OR=1.83; p=0.01) and the -863A carrier status (OR=1.82; p=0.01). After stratification according to age, this outcome remained significantly associated with the -308GA genotype in infants. Finally, protection against sepsis-associated mortality was found for the TNF-308 GA genotype (OR=0.22; p=0.04). Overall, our findings document a protective effect of the TNF-308 GA genotype for the ARDS and sepsis mortality outcomes, further providing evidence for an increased risk of ARDS associated with the TNF-863 CA genotype. Trial registration (www.clinicaltrials.gov): NCT00792883.

Lung protective strategy and prone ventilation resulting in successful outcome in a patient with ARDS due to H1N1

Acute respiratory distress syndrome (ARDS) is an acute respiratory condition caused by various pulmonary and extrapulmonary conditions including H1N1 virus infection. ARDS has a high mortality worldwide and in India various studies suggest that mortality in children is as high as 73-75%. Different lung protective ventilation strategies have recently been adopted to reduce mortality. The authors report a successful outcome in a 3.5-year-old child with ARDS secondary to H1N1 infection following use of a very low tidal volume (4-6 ml/kg) along with high positive end-expiratory pressure breathing and prone ventilation. As far as we are aware, this is the first case report of a successful outcome in a child with ARDS secondary to H1N1 in India.