Mortality Low in Pediatric Asthma, But More, Younger Patients Are Getting NIV

Intubation use has been cut in half in pediatric asthma from 2009 through 2019, while noninvasive ventilation use has more than doubled, according to study findings published in the Annals of the American Thoracic Society.

Overall hospitalization rates for asthma in the US have dropped in recent years, while the number of pediatric patients receiving intensive care management has increased.

Investigators sought to explore how the changing cohort of critically ill pediatric asthma patients has changed the use of invasive mechanical ventilation (IMV) and noninvasive mechanical ventilation (NIV).

The investigators hypothesized that patients with asthma who required pediatric intensive care unit (PICU) admission would be younger than in past years with shifting national origins, and that such patients would trend towards decreased rates of invasive mechanical ventilation and mortality. The study’s primary endpoint was endotracheal intubation with IMV.

A retrospective multicenter cohort analysis was conducted using data from 161 North American PICUs feeding the Virtual Pediatric Systems (VPS) database; this included 67,614 admissions for 56,727 unique patients (2-18 years of age) from January 2009 through December 2019. Patients with severe chronic comorbidities were excluded. Patients were predominantly male (59.5%) and included a higher percentage of Black patients than found in the US population (38.5% vs 14.2%, respectively). The investigators found 13.5% of patients with 2 or more admissions accounted for 20% of all admissions were actually readmissions. Patient-level clustering was used in analysis to account for confounding related to same-patient readmission.

The investigators found intubation occurred in 4.6% of admissions, and that this rate had decreased over time from 6.9% in 2009 to 3.4% in 2019 (P <.001). Of patients receiving IMV, 73.8% were intubated prior to arrival in the PICU, with almost 92% of these admissions coming from the emergency department. High flow nasal cannula (HFNC) or NIV preceded intubation in 55.5% of admissions where intubation occurred in the PICU.

Over the same time, noninvasive ventilation (used as the maximal respiratory support) increased from 8.9% in 2009 to 20.0% in 2019 (P <.001). In 19.8% of admissions, HFNC was the maximal support required which also increased significantly over time (adjusted odds ratio [aOR] 1.22 per year; 95% CI, 1.21-1.23; P <.001).

The researchers also found that patient demographics shifted over time to include more patients of Hispanic or Asian/Pacific Islander race/ethnicity and more patients aged 2 to 6 years. The decrease in intubation and increase in noninvasive ventilation occurred in all subgroups, and these changes were most pronounced in the youngest patients and slightly less pronounced in obese patients. Patients aged 6 to 12 years had the highest odds of requiring IMV; Hispanic and Black patients were less likely to require IMV.

Among the children studied, there were 240 deaths, 97.9% of which occurred in intubated patients. The lowest odds of mortality (after controlling for sex, age, weight, race/ethnicity) was in patients 2 to 6 years of age (aOR 0.26 compared with patients 6-12 years of age; 95% CI, 0.17-0.39; P <.001). Mortality rates over time ranged from 0.27% to 0.46% and did not differ significantly by year.

Significant study limitations include subjective decisions regarding respiratory support strategies without agreed upon guidelines and may reflect behavioral trends and preference over time, VPS database lacks detailed clinical information and data on complications and death outside of the PICU, missing data on race and ethnicity, limited body mass index data, and a lack of data on patient asthma classification, history, outpatient treatment, and pulmonary function tests.

“In critically ill children with asthma, the use of intubation has halved while the use of noninvasive ventilation has more than doubled,” investigators concluded. They added “This change in practice appears partially related to an increasingly younger patient cohort, although other factors merit exploration.” The study authors also noted that despite significant change in the approach to management, pediatric asthma-related mortality remains stable and low.