How to Make an Asthma Spacer. Part of the series: Asthma Treatments. In order to make an asthma spacer, a plastic bottle can be used with a hole cut in the middle to correspond to the entrance of the metered dose inhaler. Find out how to use an asthma spacer with help from a doctor and chief of allergy, asthma and immunology in this free video on asthma spacers. Read more: http://www.ehow.com/video_6161476_mak...