Endotracheal intubation and pediatric status asthmaticus: site of original care affects treatment

Institutional Variability in Respiratory Support Use for Pediatric Critical Asthma: A Multicenter Retrospective Study

Rationale: Over 20,000 children are hospitalized in the United States for asthma every year. Although initial treatment guidelines are well established, there is a lack of high-quality evidence regarding the optimal respiratory support devices for these patients.Objectives: The objective of this study was to evaluate institutional and temporal variability in the use of respiratory support modalities for pediatric critical asthma.Methods: We conducted a retrospective cohort study using data from the Virtual Pediatrics Systems database. Our study population included children older than 2 years old admitted to a VPS contributing pediatric intensive care unit from January 2012 to December 2021 with a primary diagnosis of asthma or status asthmaticus. We evaluated the percentage of encounters using a high-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), noninvasive bilevel positive pressure ventilation (NIV), and invasive mechanical ventilation (IMV) for all institutions, then divided institutions into quintiles based on the volume of patients. We created logistic regression models to determine the influence of institutional volume and year of admission on respiratory support modality use. We also conducted time-series analyses using Kendall's tau.Results: Our population included 77,115 patient encounters from 163 separate institutions. Institutional use of respiratory modalities had significant variation in HFNC (28.3%, interquartile range [IQR], 11.0-49.0%; P < 0.01), CPAP (1.4%; IQR, 0.3-4.3%; P < 0.01), NIV (8.6%; IQR, 3.5-16.1%; P < 0.01), and IMV (5.1%; IQR, 3.1-8.2%; P < 0.01). Increased institutional patient volume was associated with significantly increased use of NIV (odds ratio [OR], 1.33; 1.29-1.36; P < 0.01) and CPAP (OR, 1.20; 1.15-1.25; P < 0.01), and significantly decreased use of HFNC (OR, 0.80; 0.79-0.81; P < 0.01) and IMV (OR, 0.82; 0.79-0.86; P < 0.01). Time was also associated with a significant increase in the use of HFNC (11.0-52.3%; P < 0.01), CPAP (1.6-5.4%; P < 0.01), and NIV (3.7-21.2%; P < 0.01), whereas there was no significant change in IMV use (6.1-4.0%; P = 0.11).Conclusions: Higher-volume centers are using noninvasive positive pressure ventilation more frequently for pediatric critical asthma and lower frequencies of HFNC and IMV. Treatment with HFNC, CPAP, and NIV for this population is increasing in the last decade.

Case report: Foreign body aspiration requiring extracorporeal membrane oxygenation

Introduction

Foreign body aspiration is a common cause of respiratory distress in pediatrics, but the diagnosis can be challenging given aspirated objects are mostly radiolucent on chest radiographs and there is often no witnessed choking event. We present a case of a patient who was initially managed as severe status asthmaticus, requiring veno-arterial extracorporeal membrane oxygenation (VA-ECMO) for refractory hypercarbia and hypoxemia, but was later found to have bilateral bronchial foreign body aspiration. This case is unique in its severity of illness, diagnostic dilemma with findings suggesting a more common diagnosis of asthma, and use of ECMO as a bridge to diagnosis and recovery.

Patient case

A previously healthy 2-year-old boy presented during peak viral season with a 3-day history of fever, cough, coryza, and increased work of breathing over the prior 24 h. There was no reported history of choking or aspiration. He was diagnosed with asthma and treated with bronchodilator therapy. Physical examination revealed pulsus paradoxus, severe work of breathing with bilateral wheeze, and at times a silent chest. Chest radiographs showed bilateral lung hyperinflation. Following a brief period of stability on maximum bronchodilator therapies and bilevel positive pressure support, the patient had a rapid deterioration requiring endotracheal intubation, with subsequent cannulation to VA-ECMO. A diagnostic flexible bronchoscopy was performed and demonstrated bilateral foreign bodies, peanuts, in the right bronchus intermedius and the left mainstem bronchus. Removal of the foreign bodies was done by rigid bronchoscopy facilitating rapid wean from VA-ECMO and decannulation within 24 h of foreign body removal.

Conclusion

Foreign body aspiration should be suspected in all patients presenting with atypical history and physical examination findings, or in patients with suspected common diagnoses who do not progress as expected or deteriorate after a period of stability. Extracorporeal life support can be used as a bridge to diagnosis and recovery in patients with hemodynamic or respiratory instability.

Heliox for Pediatric Critical Asthma: A Multicenter, Retrospective, Registry-Based Descriptive Study

BACKGROUND

In cases of critical asthma (CA), heliox may be applied as an adjunctive rescue therapy to avoid invasive mechanical ventilation (MV), improve deposition of aerosolized medications, and enhance laminar airflow through obstructed airways. Using the Pediatric Health Information System (PHIS) registry, we evaluate heliox prescribing and explored for differences in MV rates and hospital length of stay (LOS) among children with and without heliox exposure.

METHODS

We performed a retrospective cohort study using PHIS data from 42 pediatric intensive care units among children 5-17 years of age admitted for CA from 2010 through 2019. Primary outcomes were heliox prescribing rates and trends. Secondary outcomes were invasive MV rates and LOS assessed in a subgroup of children receiving ≥ 1 adjunctive intervention(s).

RESULTS

Of the 19,780 studied, heliox was prescribed in 12.5% and linearly declined from 16.1% in 2010 to 5.6% in 2019. The overall MV rate was 12.8% and was lower in subjects receiving heliox alone (4.9%) compared to heliox plus alternative adjunctive therapies [31.2%] or children receiving non-heliox adjunctive therapies [22.1%], P < .01). Accounting for MV, no difference in LOS was observed. In exploratory adjusted models, MV free hospitalization was associated with heliox-only exposure (OR: 0.33, 95% CI: 0.17-0.63, P < .01) and exposure to multiple adjunctive therapies was associated with MV (OR: 2.48, 95% CI: 1.56-3.94, P < .01).

CONCLUSIONS

In this multicenter retrospective study from 42 children's hospitals, heliox prescribing for CA declined over the last decade. Subjects receiving multiple adjunctive therapies more commonly required invasive MV perhaps indicating a greater severity of illness. At this time, prospective trials needed to identify the role of heliox for pediatric CA.

Emergency room endotracheal intubation in children with bronchiolitis: A cohort study using a multicenter database

BACKGROUND AND AIMS

Bronchiolitis and asthma have a clinical overlap, and it has been shown that pediatric intensive care unit (PICU) patients with asthma undergoing endotracheal intubation in a community hospital emergency room (ER) have a shorter duration of mechanical ventilation (MV) and PICU length of stay (LOS) vs children undergoing intubation in a children's hospital. We aimed to determine if the setting of intubation (community vs children's hospital ER) is associated with the duration of MV and PICU LOS among children with bronchiolitis.

METHODS

With IRB approval, data in the Virtual Pediatric Systems (VPS, LLC) database were queried for bronchiolitis patients <24 months of age admitted to one of 103 predominantly North American PICUs between 1/2009 and 1/2016 who had an endotracheal tube in place at PICU admission. There were no exclusion criteria. Extracted data included ER type (community/external or children's hospital/internal), demographics, and reported comorbidities. Outcomes analyzed were duration of MV and PICU LOS. Multivariable linear regression was used to evaluate if intubation location was independently associated with the outcomes of interest.

RESULTS

Among 1934 patients, median age was 2.0 (IQR: 1.0-4.8) months, 51% were admitted from an external ER, 41% were White, 61% were male, and 28% had ≥1 comorbidity. Median duration of MV was 6.6 (4.6-9.5) days and the median PICU LOS was 7.0 (4.6-10.6) days. Children who underwent endotracheal intubation in a children's hospital ER had a modestly longer duration of MV (6.7 [4.4-9.4] vs 6.5 [5.2-9.6] days, P < .001, Mann-Whitney U) and longer PICU LOS (7.2 [4.8-10.8] vs 6.9 [4.2-10.1] days, P = .004, Mann-Whitney U). After adjusting for confounding variables, we did not observe a significant association between the location of endotracheal intubation and duration of MV or PICU LOS.

CONCLUSION

In this cohort, and unlike outcomes of near-fatal asthma, we observed that clinical outcomes of critical bronchiolitis were similar regardless of location of endotracheal intubation.

An Assessment of Asthma Therapy in the Pediatric ICU

OBJECTIVES

To describe asthma management, investigate practice variation, and describe asthma-associated charges and resource use during asthma management in the PICU.

METHODS

Children ages 2 to 18 years treated for status asthmaticus in the PICU from 2008 to 2011 are included in this study. This is a retrospective, single-center, cohort study. Data were collected by using the Intermountain Healthcare Enterprise Data Warehouse.

RESULTS

There were 262 patients included and grouped by maximal respiratory support intervention. Seventy percent of the patients did not receive escalation of respiratory support beyond nasal cannula or nonrebreather mask, and the majority of these patients received only first-tier recommended therapy. For all patients, medical imaging and laboratory charge fractions accounted for <3% and <5% of the total charges, respectively. Among nonintubated patients, the majority of these diagnostic test results were normal. Fifteen patients were intubated during our study period; 4 were intubated at our facility. Compared with outside hospital intubations, these 4 patients had longer time to intubation (>3 days versus <24 hours) and significantly longer median PICU length of stay (12.7 days versus 2.6 days).

CONCLUSIONS

In our study, the vast majority of patients with severe asthma were treated with minimal interventions alone (nasal cannula or nonrebreather mask and first-tier medications). Minimizing PICU length of stay is likely the most successful way to decrease expense during asthma care.

Illness Severity of Children Admitted to the PICU From Referring Emergency Departments

OBJECTIVES

To compare patient factors and outcomes among children admitted to PICUs from referring versus children's hospital emergency departments (EDs).

METHODS

Pediatric patients (<19 years old) admitted to PICUs from referring and children's hospital EDs from July 1, 2011 to June 30, 2013. We compared demographic and clinical factors, including severity of illness as measured by a recalibrated Pediatric Index of Mortality, version 2 score.

RESULTS

Of 80 045 children from 109 PICUs, 35.6% were admitted from referring EDs and 64.4% were admitted from children's hospital EDs. Children from referring EDs had higher illness severity (Pediatric Index of Mortality, version 2-predicted risk of mortality, 3.1% vs 2.2%, P < .001), were more likely to be mechanically ventilated within their first hour in the PICU (28.4% vs 23.4%, P < .001), and had higher observed mortality (3.3% vs 2.1%, P < .001). Once adjusted for illness severity and other confounders in a multivariable logistic regression model, there was no difference in the odds of mortality between children from referring and children's hospital EDs (odds ratio: 0.90; 95% confidence interval: 0.79 to 1.02, P = .09) CONCLUSIONS: Children transferred to PICUs from referring EDs had higher illness severity on arrival compared with children admitted from children's hospital EDs. Variations in patient selection for transfer or pretransfer treatment at referring EDs may contribute to the greater illness severity of transferred children. Referring hospitals may benefit from leveraging existing resources to improve patient stabilization before transfer.

Mechanically Ventilating the Severe Asthmatic

The management of the critically ill patients with asthma can be rather challenging. Potentially devastating complications relating to this presentation include hypoxemia, worsening bronchospasm, pulmonary aspiration, tension pneumothorax, dynamic hyperinflation, hypotension, dysrhythmias, and seizures. In contrast to various other pathologies requiring mechanical ventilation, acute asthma is generally associated with better outcomes. This review serves as a practical guide to the physician managing patients with severe acute asthma requiring mechanical ventilation. In addition to specifics relating to endotracheal intubation, we also discuss the interpretation of ventilator graphics, the recommended mode of ventilation, dynamic hyperinflation, permissive hypercapnia, as well as the role of extracorporeal membrane oxygenation and noninvasive mechanical ventilation.

Sevoflurane Therapy for Severe Refractory Bronchospasm in Children

OBJECTIVES

To describe the effect of inhaled sevoflurane in the treatment of severe refractory bronchospasm in children.

DESIGN

Retrospective case series.

SETTING

Two PICUs of tertiary general university hospitals in Spain.

PATIENTS

Ten patients ranging from 5 months to 14 years old with severe bronchospasm and acute respiratory failure requiring tracheal intubation and mechanical ventilation and treated with sevoflurane from 2008 to 2015.

INTERVENTION

Inhaled sevoflurane therapy was initiated after failure of conventional medical management and mechanical ventilation. In two patients, sevoflurane was administered through a Servo 900C ventilator (Maquet, Bridgewater, NJ) equipped with a vaporizer and in the other eight patients via the Anesthetic Conserving Device (AnaConDa; Sedana medical, Uppsala, Sweden) with a critical care ventilator.

MEASUREMENTS AND MAIN RESULTS

Inhaled sevoflurane resulted in statistically significant decreases of PaCO2 of 34.2 torr (95% CI, 8.3-60), peak inspiratory pressure of 14.3 cm H2O (95% CI, 8.6-19.9), and improvement in pH of 0.17 (0.346-0.002) within 6 hours of administration. Only one patient presented hypotension responsive to volume administration at the beginning of the treatment. All patients could be extubated within a median time of 120 hours (interquartile range, 46-216).

CONCLUSIONS

Inhaled sevoflurane therapy decreases the levels of PaCO2 and peak inspiratory pressure values, and it may be considered as a rescue therapy in patients with life-threatening bronchospasm refractory to conventional therapy.

Anesthesia and ventilation strategies in children with asthma: part I - preoperative assessment

PURPOSE OF REVIEW

Asthma is a common disease in the pediatric population, and anesthetists are increasingly confronted with asthmatic children undergoing elective surgery. This first of this two-part review provides a brief overview of the current knowledge on the underlying physiology and pathophysiology of asthma and focuses on the preoperative assessment and management in children with asthma. This also includes preoperative strategies to optimize lung function of asthmatic children undergoing surgery. The second part of this review focuses on the immediate perioperative anesthetic management including ventilation strategies.

RECENT FINDINGS

Multiple observational trials assessing perioperative respiratory adverse events in healthy and asthmatic children provide the basis for identifying risk factors in the patient's (family) history that aid the preoperative identification of at-risk children. Asthma treatment outside anesthesia is well founded on a large body of evidence. Optimization and to some extent intensifying asthma treatment can optimize lung function, reduce bronchial hyperreactivity, and minimize the risk of perioperative respiratory adverse events.

SUMMARY

To minimize the considerable risk of perioperative respiratory adverse events in asthmatic children, a good understanding of the underlying physiology is vital. Furthermore, a thorough preoperative assessment to identify children who may benefit of an intensified medical treatment thereby minimizing airflow obstruction and bronchial hyperreactivity is the first pillar of a preventive perioperative management of asthmatic children. The second pillar, an individually adjusted anesthesia management aiming to reduce perioperative adverse events, is discussed in the second part of this review.

Association of center volume with outcomes in critically ill children with acute asthma

BACKGROUND

Little is known about the relation between center volume and outcomes in children requiring intensive care unit (ICU) admission for acute asthma.

OBJECTIVE

To evaluate the association of center volume with the odds of receiving positive pressure ventilation and length of ICU stay.

METHODS

Patients 2 to 18 years of age with the primary diagnosis of asthma were included (2009-2012). Center volume was defined as the average number of mechanical ventilator cases per year for any diagnoses during the study period. In multivariable analysis, the odds of receiving positive pressure ventilation (invasive and noninvasive ventilation) and ICU length of stay were evaluated as a function of center volume.

RESULTS

Fifteen thousand eighty-three patients from 103 pediatric ICUs with the primary diagnosis of acute asthma met the inclusion criteria. Seven hundred fifty-two patients (5%) received conventional mechanical ventilation and 964 patients (6%) received noninvasive ventilation. In multivariable analysis, center volume was not associated with the odds of receiving any form of positive pressure ventilation in children with acute asthma, with the exception of high- to medium-volume centers. However, ICU length of stay varied with center volume and was noted to be longer in low-volume centers compared with medium- and high-volume centers.

CONCLUSION

In children with acute asthma, this study establishes a relation between center volume and ICU length of stay. However, this study fails to show any significant relation between center volume and the odds of receiving positive pressure ventilation; further analyses are needed to evaluate this relation in more detail.

Early administration of terbutaline in severe pediatric asthma may reduce incidence of acute respiratory failure

BACKGROUND

Severe pediatric asthma, if not immediately and aggressively treated, may progress to acute respiratory failure requiring mechanical ventilation in the pediatric intensive care unit (PICU). Intravenous (IV) terbutaline, a β2 agonist, is dispensed when the initial treatment does not improve the clinical condition.

OBJECTIVE

To investigate the influence of early initiation of IV terbutaline on the incidence of acute respiratory failure requiring mechanical ventilation in severe pediatric asthma.

METHODS

A retrospective chart review was conducted of 120 subjects (35 patients from an outside hospital emergency department [ED] with late start of terbutaline and 85 patients from the authors' hospital ED with early initiation of IV terbutaline) admitted to the PICU with severe asthma treated with continuous IV terbutaline. Responses to terbutaline treatment and outcomes were evaluated.

RESULTS

Patients transported from outlying hospital EDs had shorter pre-PICU mean durations of IV terbutaline than those transferred from the authors' ED (0.69 ± 1.38 and 2.91 ± 2.47 hours, respectively, P = .001). Twenty-one of 35 patients (60%) from outlying EDs required mechanical ventilation compared with 14 of 85 patients (16%) from the authors' ED (P = .001). Durations of pre-PICU terbutaline infusion for patients requiring mechanical ventilation were significantly shorter than those with no such requirement (P = .015).

CONCLUSION

The results of the present study, conducted in the largest number of subjects to date, suggest that early administration of continuous terbutaline in the ED may decrease acute respiratory failure and the need for mechanical respiratory (invasive and noninvasive) support in severe pediatric asthma.

Managing the paediatric patient with an acute asthma exacerbation

Children with acute asthma exacerbations frequently present to an emergency department with signs of respiratory distress. The most severe episodes are potentially life-threatening. Effective treatment depends on the accurate and rapid assessment of disease severity at presentation. This statement addresses the assessment, management and disposition of paediatric patients with a known diagnosis of asthma who present with an acute asthma exacerbation, especially preschoolers at high risk for persistent asthma. Guidance includes the assessment of asthma severity, treatment considerations, proper discharge planning, follow-up, and prescription for inhaled corticosteroids to prevent exacerbation and decrease chronic morbidity.

Acute respiratory failure

Acute respiratory failure is common in critically ill children, who are at increased risk of respiratory embarrassment because of the developmental variations in the respiratory system. Although multiple etiologies exist, pneumonia and bronchiolitis are most common. Respiratory system monitoring has evolved, with the clinical examination remaining paramount. Invasive tests are commonly replaced with noninvasive monitors. Children with ALI/ARDS have better overall outcomes than adults, although data regarding specific therapies are still lacking. Most children will have some degree of long-term physiologic respiratory compromise after recovery from ALI/ARDS. The physiologic basis for respiratory failure and its therapeutic options are reviewed here.

Patient origin is associated with duration of endotracheal intubation and PICU length of stay for children with status asthmaticus

OBJECTIVE

To describe intubation practices and duration of mechanical ventilation in children with status asthmaticus admitted from emergency departments (ERs) to pediatric intensive care units (PICUs).

DESIGN

Retrospective cohort study using the Virtual PICU Performance System database (VPS, LLC) of children with status asthmaticus admitted to a participating PICU between December 2003 and September 2006. The primary outcome measure was intubation prior to intensive care unit (ICU) admission. Secondary outcomes included length of intubation and medical length of stay.

SETTING

Thirty-five PICUs in the United States.

PATIENTS

Children who were intubated and mechanically ventilated during their ICU stay for asthma and were admitted from an ER.

RESULTS

A total of 4051 patients with status asthmaticus were identified. Intubation data were available from 35 of the 53 centers. Of all, 187 children were intubated for asthma, of which 157 were admitted from an ER and had complete data. Of all, 85 patients were from community hospital ERs and 72 were from the institution's own ER. In all, 115 (73%) patients were intubated prior to ICU admission and 42 (27%) patients were intubated after PICU admission. Of patients who received mechanical ventilation for status asthmaticus and were intubated prior to PICU admission, a greater proportion were intubated at community hospital ERs than in the institutions' own ERs. Eighty-five percent of the patients from community hospital ERs were intubated prior to PICU admission as opposed to 60% from institution's own ERs (P = .0004). However, median duration of intubation and PICU stay from community hospital ERs was significantly shorter than from the hospitals' own ERs (25 vs 42 hours P = .011; 57 vs 98 hours P = .0013, respectively). Logistic regression analysis revealed that after controlling for the effects of age, race, gender, and a revised version of the Paediatric Index of Mortality score of patients who were admitted for status asthmaticus and required mechanical ventilations, patients treated in community hospital ERs represented a greater proportion of preadmission intubation. The odds ratio for preadmission intubation was 5.1 if the patients arrived from community hospital ERs (95% confidence interval 1.91-13.6).

CONCLUSION

PATIENTS with status asthmaticus are more likely to be intubated when they are admitted from community hospital emergency rooms, although the duration of intubation and PICU stay is shorter.

Demographics, clinical course, and outcomes of children with status asthmaticus treated in a pediatric intensive care unit: 8-year review

OBJECTIVE

This study was done to understand the demographics, clinical course, and outcomes of children with status asthmaticus treated in a tertiary care pediatric intensive care unit (PICU).

METHODS

The medical charts of all patients above 5 years of age admitted to the PICU at Nationwide Children's Hospital, Columbus, OH, USA, with status asthmaticus from 2000 to 2007 were reviewed retrospectively. Data from 222 encounters by 183 children were analyzed.

RESULTS

The mean age at admission in years was 11 ± 3.8. The median PICU stay was 1 day (range, 1-12 days) and median hospital stay was 3 days. The ventilated group (n = 17) stayed a median of 2 days longer in the PICU and hospital. Nearly half of the children (n = 91; 50%) did not receive daily controller asthma medications. Adherence to asthma medications was reported in 125 patient charts of whom 43 (34%) were compliant. Exposure to smoking was reported in 167 of whom 70 (42%) were exposed. Among patients receiving metered dose inhaler (MDI), only 39 (18%) were using it with a spacer. Among 105 patient charts asthma severity data were available, of them 21 (20%) were labeled as mild intermittent, 29 (28%) were mild persistent, 26 (25%) were moderate persistent, and 29 (28%) were severe persistent. Compared to children with only one PICU admission during the study period (n = 161), children who had multiple PICU admissions (n = 22) experienced more prior emergency department visits and hospitalizations for asthma symptoms. There were no fatalities.

CONCLUSION

Asthmatics with any disease severity are at risk for life-threatening asthma exacerbations requiring PICU stay, especially those who are not adherent with their daily medications.

Pediatric status asthmaticus

Status asthmaticus is a frequent cause of admission to a pediatric intensive care unit. Prompt assessment and aggressive treatment are critical. First-line or conventional treatment includes supplemental oxygen, aerosolized albuterol, and corticosteroids. There are several second-line treatments available; however, few comparative studies have been performed and in the absence of good evidence-based treatments, the use of these therapies is highly variable and dependent on local practice and provider preference. In this article the pathophysiology and treatment of status asthmaticus is discussed, and the literature regarding second-line treatments is critically assessed to apply an evidence basis to the treatment of this severe disease.

β2-adrenergic receptor haplotype linked to intubation and mechanical ventilation in children with asthma

BACKGROUND AND AIMS

Children with asthma and respiratory failure comprise a small but significant subset of children with acute asthma. In addition to clinical and historical factors that have been associated with respiratory failure, there may also be genetic factors that predispose some asthmatic children to intubation and mechanical ventilation. However, this has not previously been assessed in this population. We hypothesized that genetic polymorphisms of the β(2)-adrenergic receptor (ADRβ(2)) are associated with intubation and mechanical ventilation in children with asthma.

MATERIALS AND METHODS

We performed genotyping of the ADRβ(2) in a pooled cohort of 104 children admitted to the intensive care unit (ICU) with a severe asthma exacerbation between 2002 and 2008. Genotype of the ADRβ(2) was compared with intubation for respiratory failure.

RESULTS

At amino acid position 16, 33% (n = 34) of children were homozygous for the glycine allele (Gly16Gly), 15% (n = 16) were homozygous for the arginine allele (Arg16Arg), and 52% (n = 54) were heterozygous (Arg16Gly). At amino acid position 27, 54% (n = 56) of children were homozygous for the glutamine allele (Gln27Gln), 8% (n = 8) were homozygous for the glutamic acid allele (Glu27Glu), and 38% (n = 40) were heterozygous (Gln27Glu). The haplotypes at these positions were Arg16Gly-Gln27Gln (29%, n = 30), Arg16Gly-Gln27Glu (22%, n = 23), Gly16Gly-Gln27Glu (16%, n = 17), Arg16Arg-Gln27Gln (16%, n = 17), Gly16Gly-Gln27Gln (9%, n = 9), and Gly16Gly-Glu27Glu (8%, n = 8). Twelve children in this cohort were intubated for respiratory failure. Intubation was not associated with age, obesity, race/ethnicity, or NHBLI asthma classification. However, children with the Arg16Gly-Gln27Gln haplotype were significantly more likely to be intubated and mechanical ventilated (OR = 4.2; 95% CI = 1.2-14.5; p = .036) than children with other haplotypes of the ADRβ(2). When examining the subset of intubated children, those with the Arg16Gly-Gln27Gln haplotype trended towards longer ICU length of stay (329 ± 270 vs. 124 ± 57 hours; p = .09), but this was not statistically significant.

CONCLUSIONS

Children with the Arg16Gly-Gln27Gln haplotype of the ADRβ(2) were four times more likely to be intubated and mechanically ventilated during severe asthma exacerbations. Genetic factors may influence the development of a more severe asthma phenotype during acute exacerbations.

Fatal and near-fatal asthma in children: the critical care perspective

OBJECTIVE

To characterize the clinical course, therapies, and outcomes of children with fatal and near-fatal asthma admitted to pediatric intensive care units (PICUs).

STUDY DESIGN

This was a retrospective chart abstraction across the 8 tertiary care PICUs of the Collaborative Pediatric Critical Care Research Network (CPCCRN). Inclusion criteria were children (aged 1-18 years) admitted between 2005 and 2009 (inclusive) for asthma who received ventilation (near-fatal) or died (fatal). Data collected included medications, ventilator strategies, concomitant therapies, demographic information, and risk variables.

RESULTS

Of the 261 eligible children, 33 (13%) had no previous history of asthma, 218 (84%) survived with no known complications, and 32 (12%) had complications. Eleven (4%) died, 10 of whom had experienced cardiac arrest before admission. Patients intubated outside the PICU had a shorter duration of ventilation (median, 25 hours vs 84 hours; P < .001). African-Americans were disproportionately represented among the intubated children and had a shorter duration of intubation. Barotrauma occurred in 15 children (6%) before admission. Pharmacologic therapy was highly variable, with similar outcomes.

CONCLUSION

Of the children ventilated in the CPCCRN PICUs, 96% survived to hospital discharge. Most of the children who died experienced cardiac arrest before admission. Intubation outside the PICU was correlated with shorter duration of ventilation. Complications of barotrauma and neuromyopathy were uncommon. Practice patterns varied widely among the CPCCRN sites.

Critical care for pediatric asthma: wide care variability and challenges for study

OBJECTIVES

To describe pediatric severe asthma care, complications, and outcomes to plan for future prospective studies by the Collaborative Pediatric Critical Care Research Network.

DESIGN

Retrospective cohort study.

SETTING

: Pediatric intensive care units in the United States that submit administrative data to the Pediatric Health Information System.

PATIENTS

Children 1-18 yrs old treated in a Pediatric Health Information System pediatric intensive care unit for asthma during 2004-2008.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thirteen-thousand five-hundred fifty-two children were studied; 2,812 (21%) were treated in a Collaborative Pediatric Critical Care Research Network and 10,740 (79%) were treated in a non-Collaborative Pediatric Critical Care Research Network pediatric intensive care unit. Medication use in individual Collaborative Pediatric Critical Care Research Network centers differed widely: ipratropium bromide (41%-84%), terbutaline (11%-74%), magnesium sulfate (23%-64%), and methylxanthines (0%-46%). Complications including pneumothorax (0%-0.6%), cardiac arrest (0.2%-2%), and aspiration (0.2%-2%) were rare. Overall use of medical therapies and complications at Collaborative Pediatric Critical Care Research Network centers were representative of pediatric asthma care at non-Collaborative Pediatric Critical Care Research Network pediatric intensive care units. Median length of pediatric intensive care unit stay at Collaborative Pediatric Critical Care Research Network centers was 1 to 2 days and death was rare (0.1%-3%). Ten percent of children treated at Collaborative Pediatric Critical Care Research Network centers received invasive mechanical ventilation compared to 12% at non-Collaborative Pediatric Critical Care Research Network centers. Overall 44% of patients who received invasive mechanical ventilation were intubated in the pediatric intensive care unit. Children intubated outside the pediatric intensive care unit had significantly shorter median ventilation days (1 vs. 3), pediatric intensive care unit days (2 vs. 4), and hospital days (4 vs. 7) compared to those intubated in the pediatric intensive care unit. Among children who received mechanical respiratory support, significantly more (41% vs. 25%) were treated with noninvasive ventilation and significantly fewer (41% vs. 58%) were intubated before pediatric intensive care unit care when treated in a Pediatric Health Information System hospital emergency department.

CONCLUSIONS

Marked variations in medication therapies and mechanical support exist. Death and other complications were rare. More than half of patients treated with mechanical ventilation were intubated before pediatric intensive care unit care. Site of respiratory mechanical support initiation was associated with length of stay.

Safety, efficacy, and tolerability of early initiation of noninvasive positive pressure ventilation in pediatric patients admitted with status asthmaticus: a pilot study

OBJECTIVES

Although noninvasive positive pressure ventilation is increasingly used for respiratory distress, there is not much data supporting its use in children with status asthmaticus. The objective of this study was to determine safety, tolerability, and efficacy of early initiation of noninvasive positive pressure ventilation in addition to standard of care in the management of children admitted with status asthmaticus.

STUDY DESIGN

A prospective, randomized, controlled, clinical trial.

PATIENTS

Twenty patients (1-18 yrs old) admitted to the pediatric intensive care unit with status asthmaticus.

METHODS AND MAIN RESULTS

Children were randomized to receive either noninvasive positive pressure ventilation plus standard of care (noninvasive positive pressure ventilation group) or standard of care alone (standard group). Improvement in clinical asthma score was significantly greater in noninvasive positive pressure ventilation group compared to standard group at 2 hrs, 4-8 hrs, 12-16 hrs, and 24 hrs after initiation of interventions (p < .01). A significant decrease in respiratory rate at ≥ 24 hrs oxygen requirement after 2 hrs was noted in noninvasive positive pressure ventilation group as compared to standard group (p = .01 and p = .03, respectively). Although statistically not significant, fewer children in the noninvasive positive pressure ventilation group required adjunct therapy compared to standard group (11% vs. 50%; p = .07). There were no major adverse events related to noninvasive positive pressure ventilation. Nine out of ten patients tolerated noninvasive positive pressure ventilation through the duration of the study; noninvasive positive pressure ventilation had to be discontinued in one patient because of persistent cough.

CONCLUSIONS

Early initiation of noninvasive positive pressure ventilation, along with short acting β-agonists and systemic steroids, can be safe, well-tolerated, and effective in the management of children with status asthmaticus.

Isoflurane for life-threatening bronchospasm: a 15-year single-center experience

BACKGROUND

Children with severe bronchospasm requiring mechanical ventilation may become refractory to conventional therapy. In these critically ill patients, isoflurane is an inhaled anesthetic agent available in some centers to treat bronchospasm. We hypothesized that isoflurane is safe and would lead to improved gas exchange in children with life-threatening bronchospasm refractory to conventional therapy.

METHODS

A retrospective review was conducted and included mechanically ventilated children treated with isoflurane in a quaternary pediatric ICU for life-threatening bronchospasm, from 1993 to 2007. Demographic, blood gas, ventilator, and outcome data were collected.

RESULTS

Thirty-one patients, with a mean age of 9.5 years (range 0.4-23 years) were treated with isoflurane, from 1993 to 2007. Mean time to initiation of isoflurane after intubation was 13 hours (0-120 h), and the mean maximum isoflurane dose was 1.1% (0.3-2.5%). Mean duration of isoflurane administration was 54.5 hours (range 1-181 h), with a total mean duration of mechanical ventilation of 252 hours (range 16-1,444 h). Isoflurane led to significant improvement in pH and P(CO(2)) within 4 hours of initiation (P ≤ .001). Complications during isoflurane administration included hypotension requiring vasoactive infusions in 24 (77%), arrhythmia in 3 (10%), neurologic side effects in 3 (10%), and pneumothorax in 1 (3%) patient.

CONCLUSIONS

Isoflurane led to improvement in pH and P(CO(2)) within 4 hours in this series of mechanically ventilated patients with life-threatening bronchospasm. The majority of patients in this series developed hypotension, but there was a low incidence of other side effects related to isoflurane administration. Isoflurane appears to be an effective therapy in patients with life-threatening bronchospasm refractory to conventional therapy. However, further investigation is warranted, given the uncertain overall impact of isoflurane in this context.

Bronchiolite e asma

La letteratura internazionale ha recentemente riconosciuto la mancanza di confini netti fra bronchiolite (BR), wheezing (WH), o respiro sibilante, e asma.

Management of severe asthma exacerbation in children

BACKGROUND

Asthma is a common disease in children and acute severe asthma exacerbation can be life-threatening. This article aims to review recent advances in understanding of risk factors, pathophysiology, diagnosis and treatment of severe asthma exacerbation in children.

DATA SOURCES

Articles concerning severe asthma exacerbation in children were retrieved from PubMed. Literatures were searched with MeSH words "asthma", "children", "severe asthma exacerbation" and relevant cross references.

RESULTS

Severe asthma exacerbation in children requires aggressive treatments with β2-agonists, anticholinergics, and corticosteroids. Early initiation of inhaled β-agonists and systemic use of steroids are recommended. Other agents such as magnesium and aminophylline have some therapeutic benefits. When intubation and mechanical ventilation are needed, low tidal volume, controlled hypoventilation with lower-than-traditional respiratory rates and permissive hypercapnia can be applied.

CONCLUSIONS

Researchers should continue to detect the risk factors, pathophysiology, diagnosis and treatment of severe asthma exacerbation in children. More studies especially randomized controlled trials are required to evaluate the efficacy and safety of standard and new therapies.

Pediatric respiratory diseases: 2011 update for the Rogers' Textbook of Pediatric Intensive Care

OBJECTIVES

To review articles relevant to the field of pediatric respiratory disease that were published after the 2008 Rogers' Textbook of Pediatric Intensive Care.

DATA SOURCES

The authors searched the PubMed database (http://www.ncbi.nlm.nih.gov/sites/entrez) from the National Library of Medicine for citations from the pediatric and adult literature relevant to pediatric status asthmaticus, bronchiolitis, pneumonia, acute lung injury, acute respiratory distress syndrome, and neonatal respiratory failure. The authors also searched the reference lists of key primary publications and recent review articles, and queried the National Institutes of Health's ClinicalTrials.gov Web site (www.clinicaltrials.gov) to obtain information about ongoing clinical trials for acute lung injury. The authors had knowledge of new publications in the field of respiratory monitoring, which were considered for inclusion in the review.

STUDY SELECTION AND DATA EXTRACTION

The authors reviewed the promising articles and the decision to include any article in the review was based on its potential to inform pediatric intensive care practice or future research.

DATA SYNTHESIS

Articles in six categories were selected for inclusion: status asthmaticus, bronchiolitis, pneumonia, acute lung injury/acute respiratory distress syndrome, respiratory monitoring, and neonatal respiratory failure.

CONCLUSIONS

There have been important new developments relevant to the pathogenesis and management of pediatric respiratory diseases. In particular, new insights into the causal pathways of respiratory syncytial virus-induced airways disease can potentially lead to novel therapies. Computed tomography imaging of the injured lung during mechanical ventilation has opened new avenues for future research directed at testing new treatments in acute lung injury subpopulations defined according to lung mechanics. Promising new monitoring techniques may play a supporting role in the conduct of these studies. Finally, evidence from the neonatal literature recently has shown how the course and future consequences of respiratory failure in this population may be modified through more widespread use of noninvasive support.

Trends in admissions for pediatric status asthmaticus in New Jersey over a 15-year period

OBJECTIVE

Status asthmaticus accounts for a large portion of the morbidity and mortality associated with asthma, but we know little about its epidemiology. We describe here the hospitalization characteristics of children with status asthmaticus, how they changed over time, and how they differed between hospitals with and without PICUs.

PATIENTS AND METHODS

We used administrative data from New Jersey that included all hospitalizations in the state from 1992, 1995, and 1999-2006. We identified children with status asthmaticus by using International Classification of Diseases, Ninth Revision, diagnosis codes that indicate status asthmaticus and the use of mechanical ventilation by using procedure codes. We designated hospitals with a PICU as "PICU hospitals" and those without as "adult hospitals."

RESULTS

We identified 28 309 admissions of children with status asthmaticus (22.8% of all asthma hospitalizations). From 1992 to 2006, the rate of hospital admissions decreased by half (from 1.98 in 1000 to 0.93 in 1000 children), and there was a 70% decrease in the number of children admitted to adult hospitals. The rate of ICU care in PICU hospitals more than tripled. However, the rate of mechanical ventilation remained low, and the number of deaths was small and unchanged (n=14 total). Hospital costs climbed from $6.6 million to $9.5 million.

CONCLUSIONS

Although fewer children are being admitted with status asthmaticus, the proportion of patients managed in PICUs is climbing. There has been no substantial change in rates of mechanical ventilation or death. Additional research is needed to better understand how patients and physicians decide on the appropriate site for hospital care and how that choice affects outcome.

Acute severe asthma: new approaches to assessment and treatment

The precise definition of a severe asthmatic exacerbation is an issue that presents difficulties. The term 'status asthmaticus' relates severity to outcome and has been used to define a severe asthmatic exacerbation that does not respond to and/or perilously delays the repetitive or continuous administration of short-acting inhaled beta(2)-adrenergic receptor agonists (SABA) in the emergency setting. However, a number of limitations exist concerning the quantification of unresponsiveness. Therefore, the term 'acute severe asthma' is widely used, relating severity mostly to a combination of the presenting signs and symptoms and the severity of the cardiorespiratory abnormalities observed, although it is well known that presentation does not foretell outcome. In an acute severe asthma episode, close observation plus aggressive administration of bronchodilators (SABAs plus ipratropium bromide via a nebulizer driven by oxygen) and oral or intravenous corticosteroids are necessary to arrest the progression to severe hypercapnic respiratory failure leading to a decrease in consciousness that requires intensive care unit (ICU) admission and, eventually, ventilatory support. Adjunctive therapies (intravenous magnesium sulfate and/or others) should be considered in order to avoid intubation. Management after admission to the hospital ward because of an incomplete response is similar. The decision to intubate is essentially based on clinical judgement. Although cardiac or respiratory arrest represents an absolute indication for intubation, the usual picture is that of a conscious patient struggling to breathe. Factors associated with the increased likelihood of intubation include exhaustion and fatigue despite maximal therapy, deteriorating mental status, refractory hypoxaemia, increasing hypercapnia, haemodynamic instability and impending coma or apnoea. To intubate, sedation is indicated in order to improve comfort, safety and patient-ventilator synchrony, while at the same time decrease oxygen consumption and carbon dioxide production. Benzodiazepines can be safely used for sedation of the asthmatic patient, but time to awakening after discontinuation is prolonged and difficult to predict. The most common alternative is propofol, which is attractive in patients with sudden-onset (near-fatal) asthma who may be eligible for extubation within a few hours, because it can be titrated rapidly to a deep sedation level and has rapid reversal after discontinuation; in addition, it possesses bronchodilatory properties. The addition of an opioid (fentanyl or remifentanil) administered by continuous infusion to benzodiazepines or propofol is often desirable in order to provide amnesia, sedation, analgesia and respiratory drive suppression. Acute severe asthma is characterized by severe pulmonary hyperinflation due to marked limitation of the expiratory flow. Therefore, the main objective of the initial ventilator management is 2-fold: to ensure adequate gas exchange and to prevent further hyperinflation and ventilator-associated lung injury. This may require hypoventilation of the patient and higher arterial carbon dioxide (PaCO(2)) levels and a more acidic pH. This does not apply to asthmatic patients intubated for cardiac or respiratory arrest. In this setting the post-anoxic brain oedema might demand more careful management of PaCO(2) levels to prevent further elevation of intracranial pressure and subsequent complications. Monitoring lung mechanics is of paramount importance for the safe ventilation of patients with status asthmaticus. The first line of specific pharmacological therapy in ventilated asthmatic patients remains bronchodilation with a SABA, typically salbutamol (albuterol). Administration techniques include nebulizers or metered-dose inhalers with spacers. Systemic corticosteroids are critical components of therapy and should be administered to all ventilated patients, although the dose of systemic corticosteroids in mechanically ventilated asthmatic patients remains controversial. Anticholinergics, inhaled corticosteroids, leukotriene receptor antagonists and methylxanthines offer little benefit, and clinical data favouring their use are lacking. In conclusion, expertise, perseverance, judicious decisions and practice of evidence-based medicine are of paramount importance for successful outcomes for patients with acute severe asthma.

Experience with use of extracorporeal life support for severe refractory status asthmaticus in children

Introduction

Severe status asthmaticus (SA) in children may require intubation and mechanical ventilation with a subsequent increased risk of death. In the patient with SA and refractory hypercapnoeic respiratory failure, use of extracorporeal life support (ECLS) has been anecdotally reported for carbon dioxide removal and respiratory support. We aimed to review the experience of a single paediatric centre with the use of ECLS in children with severe refractory SA, and to compare this with international experience from the Extracorporeal Life Support Organization (ELSO) registry.

Methods

All paediatric patients (aged from 1 to 17 years) with primary International Classification of Diseases (ICD)-9 diagnoses of SA receiving ECLS for respiratory failure from both the Children's Healthcare of Atlanta at Egleston (Children's at Egleston) database and the ELSO registry were reviewed.

Results

Thirteen children received ECLS for refractory SA at the Children's at Egleston from 1986 to 2007. The median age of the children was 10 years (range 1 to 16 years). Patients generally received aggressive use of medical and anaesthetic therapies for SA before cannulation with a median partial pressure of arterial carbon dioxide (PaCO₂) of 130 mmHg (range 102 to 186 mmHg) and serum pH 6.89 (range 6.75 to 7.03). The median time of ECLS support was 95 hours (range 42 to 395 hours). All 13 children survived without neurological sequelae. An ELSO registry review found 64 children with SA receiving ECLS during the same time period (51 excluding the Children's at Egleston cohort). Median age, pre-ECLS PaCO₂ and pH were not different in non-Children's ELSO patients. Overall survival was 60 of 64 (94%) children, including all 13 from the Children's at Egleston cohort. Survival was not significantly associated with age, pre-ECLS PaCO₂, pH, cardiac arrest, mode of cannulation or time on ECLS. Significant neurological complications were noted in 3 of 64 (4%) patients; patients with neurological complications were not significantly more likely to die (P = 0.67).

Conclusions

Single centre and ELSO registry experience provide results of a cohort of children with refractory SA managed with ECLS support. Further study is necessary to determine if use of ECLS in this setting produces better outcomes than careful mechanical ventilation and medical therapy alone.

Intravenous ketamine in a dissociating dose as a temporizing measure to avoid mechanical ventilation in adult patient with severe asthma exacerbation

BACKGROUND

Patients experiencing severe asthma exacerbations occasionally deteriorate to respiratory failure requiring endotracheal intubation and mechanical ventilation. Mechanical ventilation in this setting exposes the patients to substantial iatrogenic risk and should be avoided if at all possible.

OBJECTIVES

To describe the use of intravenous ketamine in acute asthma exacerbation.

CASE REPORT

We present a case of severe asthma exacerbation in an adult female patient who failed to improve with standard therapies, but promptly improved with the administration of intravenous ketamine (0.75 mg/kg i.v. bolus followed by continuous drip of 0.15 mg/kg/h).

SUMMARY

This case suggests that intravenous ketamine given in a dissociative dose may be an effective temporizing measure to avoid mechanical ventilation in adult patients with severe asthma exacerbations.

The increased cost of complications in children with status asthmaticus

Status asthmaticus is one of the most common causes of admission to a pediatric intensive care unit (PICU). There is little published data, however, examining the complications associated with the treatment of status asthmaticus in children in the PICU. Our hypothesis was that children experiencing a complication would have an increased duration of hospitalization for status asthmaticus. We performed a retrospective review of the complication profile and hospital course of all children admitted to a PICU with status asthmaticus over a 9 years period. Twenty-two (8%) of the 293 children admitted to the ICU with status asthmaticus experienced one or more complications during their treatment. The most common complications were aspiration pneumonia, ventilator-associated pneumonia, pneumomediastinum, pneumothorax, and rhabdomyolysis. Intubated children were significantly more likely than non-intubated children to experience a complication (RR 15.3; 95% CI 6.7-35). Fifteen (42%) of the 36 intubated children experienced a complication. Intubated children experiencing a complication had significantly longer duration of mechanical ventilation (163 +/- 169 hr vs. 66 +/- 65 hr, P = 0.03), ICU length of stay (237 +/- 180 hr vs. 124 +/- 86 hr, P = 0.02) and hospital charges (US dollars 117,184 +/- 111,191 vs. US dollars 38,788 +/- 27,784; P = 0.001) than intubated children not experiencing a complication. In this review, complications were associated with increased morbidity and duration of hospitalization in children with status asthmaticus, particularly in those intubated as part of their therapy. This suggests that intubation and mechanical ventilation itself may increase the risk of developing a complication in this population.