意识水平下降可能会导致咳嗽反射减弱和声门闭合障碍。意识改变可由酒精、毒品或麻醉品引起。[4]Lanspa MJ, Peyrani P, Wiemken T, et al. Characteristics associated with clinician diagnosis of aspiration pneumonia: a descriptive study of afflicted patients and their outcomes. J Hosp Med. 2015;10:90-96.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4310822/http://www.ncbi.nlm.nih.gov/pubmed/25363892?tool=bestpractice.com[10]Marik PE, Kaplan D. Aspiration pneumonia and dysphagia in the elderly. Chest. 2003;124:328-336.http://www.ncbi.nlm.nih.gov/pubmed/12853541?tool=bestpractice.com[11]Johnson JL, Hirsch CS. Aspiration pneumonia. Postgrad Med. 2003;113:99-102,105-106,111-112.http://www.ncbi.nlm.nih.gov/pubmed/12647477?tool=bestpractice.com[16]Manabe T, Teramoto S, Tamiya N, et al. Risk factors for aspiration pneumonia in older adults. PLoS One. 2015;10:e0140060.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4596873/http://www.ncbi.nlm.nih.gov/pubmed/26444916?tool=bestpractice.com