发生于老年患者中的大部分医院获得性肺炎及相当比例的社区获得性肺炎由感染性口咽分泌物微量误吸所致。采取措施发现口咽部吞咽困难,减少口咽部病原微生物负荷可能有助于减少吸入性肺炎,尤其是对于神经系统疾病患者、存在共病的养老院患者、气管插管及应用饲管的患者。[22]Sarin J, Balasubramaniam R, Corcoran AM, et al. Reducing the risk of aspiration pneumonia among elderly patients in long-term care facilities through oral health preventions. J Am Med Dir Assoc. 2008;9:128-135.http://www.ncbi.nlm.nih.gov/pubmed/18261707?tool=bestpractice.com
许多随机、对照临床试验试图评估可减少吸入性肺炎的干预措施,其中有许多因有偏倚的高风险而被质疑,还有许多研究仍发现在减少误吸或吸入性肺炎方面无显著差异。[23]Loeb MB, Becker M, Eady A, et al. Interventions to prevent aspiration pneumonia in older adults: a systematic review. J Am Geriatr Soc. 2003;51:1018-1022.http://www.ncbi.nlm.nih.gov/pubmed/12834525?tool=bestpractice.com
严密护理对防止口咽物误吸很必要。老年人或神经系统功能障碍的患者应缓慢进食或鼻饲少量、适当稠度的食物,防止窒息或反流。提倡维护良好的口腔卫生。口腔护理包括每周1次专业口腔清洁,每餐后刷牙,每天清洗假牙1次,消毒液漱口等措施,能够降低口咽分泌物中致病细菌的数量,并有可能减少吸入性肺炎的发生率和病死率。[24]Yoneyama T, Yoshida M, Ohrui T, et al. Oral care reduces pneumonia in older patients in nursing homes. J Am Geriatr Soc. 2002;50:430-433.http://www.ncbi.nlm.nih.gov/pubmed/11943036?tool=bestpractice.com[25]Sjögren P, Nilsson E, Forsell M, et al. A systematic review of the preventive effect of oral hygiene on pneumonia and respiratory tract infection in elderly people in hospitals and nursing homes: effect estimates and methodological quality of randomized controlled trials. J Am Geriatr Soc. 2008;56:2124-2130.http://www.ncbi.nlm.nih.gov/pubmed/18795989?tool=bestpractice.com[26]Scannapieco FA. Pneumonia in nonambulatory patients: the role of oral bacteria and oral hygiene. J Am Dent Assoc. 2006;137(suppl 2):21S-25S.http://www.ncbi.nlm.nih.gov/pubmed/17012732?tool=bestpractice.com[27]van der Maarel-Wierink CD, Vanobbergen JN, Bronkhorst EM, et al. Oral health care and aspiration pneumonia in frail older people: a systematic literature review. Gerodontology. 2013;30:3-9.http://www.ncbi.nlm.nih.gov/pubmed/22390255?tool=bestpractice.com不可修复的牙齿应予拔除。
口腔护理的最新趋势已超出口腔消毒范围,更强调通过治疗吞咽困难(吞咽训练、饮食管理和体位)以增加口咽分泌物动力的重要性。尚不确定这一方法是否能够减少肺炎的发生,但有可能减少吞咽功能受损患者的误吸。[28]Tada A, Miura H. Prevention of aspiration pneumonia (AP) with oral care. Arch Gerontol Geriatr. 2012;55:16-21.http://www.ncbi.nlm.nih.gov/pubmed/21764148?tool=bestpractice.com由牙科专业人员提供口腔护理似乎能有最大获益;由护士提供的口腔护理未能显著降低肺炎的死亡率。[29]Sjögren P, Wårdh I, Zimmerman M, et al. Oral care and mortality in older adults with pneumonia in hospitals or nursing homes: systematic review and meta-analysis. J Am Geriatr Soc. 2016;64:2109-2115.http://www.ncbi.nlm.nih.gov/pubmed/27590446?tool=bestpractice.com
体位设计和锻炼以加强吞咽的肌肉力量,可能有利于有吞咽功能障碍的体弱患者。
患者应于饭后保持直立或抬高体位至少1-2小时。鼻饲管需要定期调整,以防止异位。应当监测胃中的管饲残余容量,如果残余容量超过 50 mL,应当暂停管饲。与定时灌注相比,持续鼻饲泵入并不能降低肺炎的发生率。在危重病患者中,有中等质量证据证明,与经胃喂养相比,经幽门后喂养可使肺炎发生率降低 30%。[30]Alkhawaja S, Martin C, Butler RJ, et al. Post-pyloric versus gastric tube feeding for preventing pneumonia and improving nutritional outcomes in critically ill adults. Cochrane Database Syst Rev. 2015;(8):CD008875.http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD008875.pub2/fullhttp://www.ncbi.nlm.nih.gov/pubmed/26241698?tool=bestpractice.com胃造瘘患者应用要素饮食[31]Horiuchi A, Nakayama Y, Sakai R, et al. Elemental diets may reduce the risk of aspiration pneumonia in bedridden gastrostomy-fed patients. Am J Gastroenterol. 2013;108:804-810.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3647233/http://www.ncbi.nlm.nih.gov/pubmed/23399554?tool=bestpractice.com和莫沙比利[32]Takatori K, Yoshida R, Horai A, et al. Therapeutic effects of mosapride citrate and lansoprazole for prevention of aspiration pneumonia in patients receiving gastrostomy feeding. J Gastroenterol. 2013;48:1105-1110.http://www.ncbi.nlm.nih.gov/pubmed/23238778?tool=bestpractice.com可减少吸入性肺炎发生。
误吸之后预防性应用抗生素可能无法预防随后细菌性肺炎的发生;相反,它可能会筛选出耐药菌。对于吸入性肺炎的药物性预防干预,目前尚无基于循证医学的推荐。[33]El Solh AA, Saliba R. Pharmacologic prevention of aspiration pneumonia: a systematic review. Am J Geriatr Pharmacother. 2007;5:352-362.http://www.ncbi.nlm.nih.gov/pubmed/18179994?tool=bestpractice.com
几乎没有证据表明术前禁食可降低围术期误吸的风险。[34]Brady M, Kinn S, Ness V, et al. Preoperative fasting for preventing perioperative complications in children. Cochrane Database Syst Rev. 2009;(4):CD005285.http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD005285.pub2/fullhttp://www.ncbi.nlm.nih.gov/pubmed/19821343?tool=bestpractice.com对于不具有明显增高的吸入性肺炎风险的患者(这些增加风险的疾病包括:胃食管反流病、食管裂孔疝、肠梗阻、肠道管饲患者、怀孕和肥胖),不推荐术前常规应用抑酸剂或相关药物来抑制胃酸分泌物。[17]American Society of Anesthesiologists. Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: application to healthy patients undergoing elective procedures: an updated report by the American Society of Anesthesiologists Task Force on Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration. Anesthesiology. 2017;126:376-393.http://www.ncbi.nlm.nih.gov/pubmed/28045707?tool=bestpractice.com一篇系统评价显示,应用组胺 H2 受体拮抗剂有益,可以减少胃容量并提高 pH 值,从而减少存在误吸胃酸风险的患者数量。[35]Puig I, Calzado S, Suárez D, et al. Meta-analysis: comparative efficacy of H2-receptor antagonists and proton pump inhibitors for reducing aspiration risk during anaesthesia depending on the administration route and schedule. Pharmacol Res. 2012;65:480-490.http://www.ncbi.nlm.nih.gov/pubmed/22289674?tool=bestpractice.com尽管如此,并没有足够的证据表明支持抑制胃酸分泌,因为给予质子泵抑制剂或组胺 H2 受体拮抗剂可能与肺炎风险增加有关。[36]Eom CS, Jeon CY, Lim JW, et al. Use of acid-suppressive drugs and risk of pneumonia: a systematic review and meta-analysis. CMAJ. 2011;183:310-319.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3042441/http://www.ncbi.nlm.nih.gov/pubmed/21173070?tool=bestpractice.com
对于全麻剖宫产的孕妇,应用H2受体拮抗剂同样显示出误吸性肺炎风险降低的趋势,但证据质量较差。[37]Paranjothy S, Griffiths JD, Broughton HK, et al. Interventions at caesarean section for reducing the risk of aspiration pneumonitis. Cochrane Database Syst Rev. 2014;(2):CD004943.http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD004943.pub4/fullhttp://www.ncbi.nlm.nih.gov/pubmed/24497372?tool=bestpractice.com
一项研究显示,对于使用鼻饲管的卒中患者,在发生卒中后 7 日内,与使用安慰剂相比,使用甲氧氯普胺能降低肺炎发生率。[38]Warusevitane A, Karunatilake D, Sim J, et al. Safety and effect of metoclopramide to prevent pneumonia in patients with stroke fed via nasogastric tubes trial. Stroke. 2015;46:454-460.http://stroke.ahajournals.org/content/46/2/454.longhttp://www.ncbi.nlm.nih.gov/pubmed/25516196?tool=bestpractice.com