Background Prophylactic antimicrobial therapy is frequently prescribed for acute aspiration pneumonitis, with the intent of preventing the development of aspiration pneumonia. However, few clinical studies have examined the benefits and harms of this practice. Methods A retrospective cohort study design was used to compare outcomes of patients with aspiration pneumonitis who received prophylactic antimicrobial therapy with those managed with supportive care only during the initial 2 days following macroaspiration. The primary outcome was in-hospital mortality within 30 days. Secondary outcomes included transfer to critical care and antimicrobial therapy received between days 3 and 14 following macroaspiration including escalation of therapy and antibiotic-free days. Results Among 1483 patients reviewed, 200 met the case definition for acute aspiration pneumonitis, including 76 (38%) who received prophylactic antimicrobial therapy and 124 (62%) who received supportive management only. After adjusting for patient-level predictors, antimicrobial prophylaxis was not associated with any improvement in mortality (odds ratio, 0.9; 95% confidence interval [CI], 0.4-1.7; P = .7). Patients receiving prophylactic antimicrobial therapy were no less likely to require transfer to critical care (5% vs 6%; P = .7) and subsequently received more frequent escalation of antibiotic therapy (8% vs 1%; P = .002) and fewer antibiotic-free days (7.5 vs 10.9; P < .0001). Conclusions Prophylactic antimicrobial therapy for patients with acute aspiration pneumonitis does not offer clinical benefit and may generate antibiotic selective pressures that results in the need for escalation of antibiotic therapy among those who develop aspiration pneumonia.

中文翻译：

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急性吸入性肺炎的预防性抗菌治疗。

背景技术对于急性吸入性肺炎，经常开预防性抗菌治疗，以防止吸入性肺炎的发生。但是，很少有临床研究检查这种做法的利弊。方法采用回顾性队列研究设计，比较仅在大吸气后的最初两天内接受预防性抗菌治疗的吸入性肺炎患者与支持治疗的患者的结局。主要结局是30天内的院内死亡率。次要结果包括在大吸气后3到14天之间转移至重症监护室和接受抗微生物治疗，包括治疗逐步升级和无抗生素治疗。结果在1483例患者中，200例符合急性吸入性肺炎的病例定义，包括接受预防性抗菌治疗的76例（38％）和仅接受支持治疗的124例（62％）。在根据患者水平的预测因素进行调整后，抗菌药物的预防与死亡率的任何改善均不相关（赔率比为0.9； 95％置信区间[CI]为0.4-1.7； P = 0.7）。接受预防性抗生素治疗的患者不太可能需要转危重症护理（5％vs 6％; P = .7），随后接受更频繁的抗生素治疗升级（8％vs 1％; P = .002），且较少无抗生素天数（7.5比10.9； P <.0001）。