(1) Respiratory disease Asthma has been a significant underlying condition in children and adults hospitalized with critical illness [27, 61] . Data from the USA and Canada illustrate that, prior to puberty, boys have more asthma exacerbations than girls. However, this trend is reversed in adulthood [39] . Rates of asthma attacks, numbers of asthma-related emergency room visits, numbers of asthma-related hospitalizations and duration of hospitalization are higher in women than men in the USA [39, 62] . Rates of asthma, as well as incidence of asthma attacks, appear to be the same in pregnant and age-matched non-pregnant women [63] .