Reduction in mortality from bronchiolitis in developed health is principally achieved from the availability of critical care. Different health care providers and countries demonstrate considerable variance in admission rates, but globally the use and cost of this resource are increasing. The reasons of this are multifold and include organizational, cultural, and clinical aspects. The organization of care has evolved differently in different health care settings at the threshold of critical need, with local priorities and resources determining the location of care (ward or critical care). Critical care areas adopting high-flow oxygen therapy (HFOT) (a ward-based therapy in some institutions) have seen significant increase in their occupancy, without change in rates of mechanical ventilation. Culturally, some countries appear to have a lower threshold for intubation and mechanical ventilation: United States (18%), Finland (4%), and even in countries with high rates of critical care admission (27% in Australia and New Zealand), intubation rates can decline with time (reducing from 27% to 11%). Baseline clinical characteristics of children admitted to critical care are remarkably similar, children are young (c30-60 days) and often born prematurely (21-46%). Clinical thresholds for admission as predefined by critical care units in online guidance focus on presence of apnea (observed in 7-42% of admissions), low pulse oxygen saturation and subjective measures (exhaustion and reduced consciousness). Clinical characteristics of children at the time of admission are commonly reported in relation to the modified Woods Clinical Asthma Score (mean = 3.8 to ≥7) and raised pCO (range = 8.0-8.8 kPa), with pCO the only significant parameter in a multivariate analysis of factors associated with intubation. KEY POINTS: · More children are being admitted to intensive care over time with increased costs.. · Cultural, organizational, and clinical variance exist between centers and countries.. · Comparing and aligning admissions is difficult as there are no standardized criteria..Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.