Children with asthma exacerbations requiring pediatric ICU (PICU) admission, known as critical asthma (CA), are prescribed a variety of therapeutic interventions including heliox. Delivered invasively and noninvasively, heliox is employed to enhance deposition of aerosolized medications, improve obstructive pulmonary pathophysiology, and avoid complications associated with invasive mechanical ventilation. We used the Virtual Pediatric Systems database to update estimates of heliox prescription and explore for relationships between heliox and mechanical ventilation frequency and duration.We performed a retrospective cohort study using data from 97 PICUs among children 3-17 y of age admitted for CA from 2013-2019. The primary outcome was heliox prescribing rates and trends. Subgroup analyses assessed mechanical ventilation rates and duration by heliox exposure.Of 43,238 subjects studied, 1,070 (2.5%) were prescribed heliox. Mean heliox prescribing rates fell from 4.11% in 2013 to 2.37% in 2019. Heliox use was greater from centers in the South (2.6%) and Midwest (3.3%) as compared to the West (1.6%) and Northeast United States (1.6%, P < .001). In the subgroup assessing mechanical ventilation frequency, mechanical ventilation rates were 273/39,739 (0.7%) and greater for those provided heliox (1.9% vs 0.7%, P < .001). In the subgroup assessing mechanical ventilation duration, no differences in median mechanical ventilation duration were observed (4.94 [interquartile range [IQR] 3.04-6.36] vs 4.63 [IQR 3.11-7.30] d; P = .35) for those with and without heliox. In exploratory adjusted models, noninvasive heliox was not associated with mechanical ventilation. Mortality was rare (206/43,238 [0.47%]) and predominantly among subjects intubated prehospitalization (188/206 [91.3%]).Heliox as adjunctive therapy for children with CA is uncommon (2.5%) and not associated with mechanical ventilation or decreased mechanical ventilation duration in adjusted models. Updated estimates provided herein inform prospective controlled trial development to better define the role of heliox for CA.