Obesity impacts need for mechanical ventilation in pediatric status asthmaticus cases

Key takeaways:

• Obesity was associated with mechanical ventilation during ICU admission.
• Race and payor did not interact with BMI for mechanical ventilation.
• Race impacted the association between obesity and ICU length of stay.

WASHINGTON — Obesity was associated with a greater need for mechanical ventilation among children and adolescents with status asthmaticus, according to data presented at the American Thoracic Society International Conference.

The patient’s race and payor did not impact this association, Anoopindar K. Bhalla, MD, MsCI, department of anesthesiology and critical care medicine, Children’s Hospital Los Angeles, and colleagues wrote.

“Our biggest question was, ‘Does race or payor status impact the association between obesity and outcome in critically ill children in the ICU?’” Bhalla told Healio.

Although previous studies have separately shown differences in asthma severity based on race and body habitus, the researchers wrote, information about these associations in critically ill children with asthma has been limited. Also, socioeconomic factors may mitigate the impact that race has on body habitus and asthma, the researchers noted.

Using the Virtual PICU Systems (VPS) database, the retrospective observational study included children and adolescents aged 2 to 19 years with a first or second degree diagnosis of status asthmaticus between 2010 and 2020.

The 16,211 patients in the analysis included 1,557 (9.6%) with underweight, 8,180 (50.3%) with healthy weight, 2,312 (14.2%) with overweight and 4,225 (26%) with obesity.

First degree outcomes were defined as invasive or noninvasive mechanical ventilation within the first hour of ICU admission. Second degree outcomes included mechanical ventilation after the first hour but not in the first hour (n = 329; 4%) and PICU length of stay.

The cohort also included 4,384 (27%) who were white, 7,497 (46%) who were Black, 2,201 (14%) who were Hispanic and 2,129 (13%) who were other race. Coverage included 4,552 (28%) with commercial insurance, 11,135 (68.4%) with government insurance and 587 (3.6%) with other insurance.

“Patients who were obese had a significantly higher odds ratio for mechanical ventilation within the first hour,” Bhalla said. “There was no interaction by race or payor status, but Black patients were independently more likely to have mechanical ventilation within the first hour.”

These odds ratios included 1.15 (95% CI, 1.04-1.28) for obesity and 1.17 (95% CI, 1.04-1.32) for Black race.

Similarly, there was no significant interaction by race or payor status among the patients who received mechanical ventilation after the first hour but not during the first hour.

“Again, obese patients were more likely to get mechanically ventilated after the first hour, but that association with Black race went away,” Bhalla said.

The odds ratio for obesity and mechanical ventilation after the first hour of ICU admission was 1.73 (95% CI, 1.33-2.26).

The median length of stay in the ICU among survivors was 1.37 days (interquartile range, 0.82-2.26). Children with obesity who were white (HR = 0.85; 95% CI, 0.8-0.9) or other race (HR = 0.86; 95% CI, 0.77-0.97) had longer stays in the ICU.

“We don’t see that association in Black patients or Hispanic patients,” Bhalla said. “It really is kind of interesting and not necessarily what we expected.”

Potentially, Bhalla said, this may reflect a lack of controlling for severity of illness with mechanical ventilation after the first hour.

“These kids are coming in sicker,” she said.

Or, Bhalla continued, there may be unconscious bias in how patients are managed in the ICU, with different levels of concern, differences in how patients are weaned off therapies, or other explanations.

The researchers further reported that 89 patients (0.55%) died.

“They’re usually dying because of severe neurologic injury from bad CPR before they get to the ICU,” Bhalla said.

Some patients who get intubated for status asthmaticus might not need that treatment, Bhalla continued.

“When you look at the difference, those patients actually come off the ventilator faster. When you deliver continuous bronchodilators through an endotracheal tube, it works pretty well,” she said. “We don’t have a lot of patients who are dying because we can’t manage their asthma in the ICU.”

Overall, the researchers concluded that race or payor did not have any impact on the association between obesity and a greater need for mechanical ventilation among children with status asthmaticus, although race impacted the association between obesity and length of stay in the ICU.

“It’s somewhat reassuring that mechanical ventilation does not seem to differ by race or payor status,” Bhalla said. “But we need to think about this a little bit more and whether we’re biased on how we manage these patients.”

The researchers called for further studies into whether there is a physiologic basis for this difference or if it reflects racial biases in ICU management.

“These are not very granular variables, race and payor status,” Bhalla said. “There are some efforts to start adding Childhood Opportunity Index.”

The Childhood Opportunity Index, Bhalla explained, incorporates multiple socioeconomic influences on health, such as environmental factors and access to education, all coded by census tract.

“That would be really interesting to look at once we have those data,” she said.

For more information:

Anoopindar K. Bhalla, MD, MsCI, can be reached at abhalla@chla.usc.edu.