Figure 1 is an algorithm for outpatient management of croup based on illness severity. 25 – 34 Keeping a symptomatic child calm by avoiding distressing procedures is important because agitation may worsen airway obstruction. Positioning the child so that he or she is comfortable is appropriate because no particular position has been shown to be more beneficial in the assessment. Oxygen should be administered when the child is hypoxic or in severe respiratory distress. Heliox, a helium-oxygen mixture, has been used to reduce airflow resistance and turbulence. Although case reports have been encouraging, a systematic review found insufficient evidence that heliox is beneficial for croup. 35 Likewise, studies do not support the routine use of exposure to cold air, antipyretics, analgesics, antitussives, decongestants, or prophylactic antibiotics.
In 1864, the first steam-driven nebulizer was invented in Germany. This inhaler, known as "Siegle’s steam spray inhaler", used the Venturi principle to atomize liquid medication, and this was the very beginning of nebulizer therapy. The importance of droplet size was not yet understood, so the efficacy of this first device was unfortunately mediocre for many of the medical compounds. The Siegle steam spray inhaler consisted of a spirit burner, which boiled water in the reservoir into steam that could then flow across the top and into a tube suspended in the pharmaceutical solution. The passage of steam drew the medicine into the vapor, and the patient inhaled this vapor through a mouthpiece made of glass. 
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