Driks M R, Craven D E, Celli B R, Manning M, Burke R A, Garvin G M, Kunches L M, Farber H W, Wedel S A, McCabe W R
Department of Medicine, Boston University School of Medicine, MA.
N Engl J Med. 1987 Nov 26;317(22):1376-82. doi: 10.1056/NEJM198711263172204.
Gram-negative nosocomial pneumonia may result from retrograde colonization of the pharynx from the stomach, and this may be more likely when the gastric pH is relatively high. We studied the rate of nosocomial pneumonia among 130 patients given mechanical ventilation in an intensive care unit who were receiving as prophylaxis for stress ulcer either sucralfate (n = 61), which does not raise gastric pH, or conventional treatment with antacids, histamine type 2 (H2) blockers, or both (n = 69). At the time of randomization to treatment, the two groups were similar in age, underlying diseases, and severity of acute illness. Patients in the sucralfate group had a higher proportion of gastric aspirates with a pH less than or equal to 4 (P less than 0.001) and significantly lower concentrations of gram-negative bacilli (P less than 0.05) in gastric aspirates, pharyngeal swabs, and tracheal aspirates than did patients in the antacid-H2-blocker group. The rate of pneumonia was twice as high in the antacid-H2 group as in the sucralfate group (95 percent confidence interval, 0.89 to 4.58; P = 0.11). Gram-negative bacilli were isolated more frequently from the tracheal aspirates of patients with pneumonia who were receiving antacids or H2 blockers. Mortality rates were 1.6 times higher in the antacid-H2 group than in the sucralfate group (95 percent confidence interval, 0.99 to 2.50; P = 0.07). Although our results fell just short of statistical significance when they were analyzed according to intention to treat, they suggest that agents that elevate gastric pH increase the risk of nosocomial pneumonia in patients receiving ventilation by favoring gastric colonization with gram-negative bacilli. We conclude that in patients receiving mechanical ventilation, the use of a prophylactic agent against stress-ulcer bleeding that preserves the natural gastric acid barrier against bacterial overgrowth may be preferable to antacids and H2 blockers.
革兰阴性菌医院获得性肺炎可能源于胃内容物逆行定植于咽部，当胃内pH值相对较高时，发生这种情况的可能性可能更大。我们研究了130例在重症监护病房接受机械通气的患者的医院获得性肺炎发生率，这些患者作为应激性溃疡的预防措施，分别接受硫糖铝（n = 61），其不会升高胃内pH值，或接受抗酸剂、组胺2型（H2）受体阻滞剂或两者联合的传统治疗（n = 69）。在随机分组接受治疗时，两组患者在年龄、基础疾病和急性疾病严重程度方面相似。硫糖铝组患者胃吸出物pH值小于或等于4的比例更高（P < 0.001），且胃吸出物、咽拭子和气管吸出物中革兰阴性杆菌的浓度显著低于抗酸剂 - H2受体阻滞剂组患者（P < 0.05）。抗酸剂 - H2受体阻滞剂组的肺炎发生率是硫糖铝组的两倍（95%置信区间，0.89至4.58；P = 0.11）。在接受抗酸剂或H2受体阻滞剂治疗的肺炎患者的气管吸出物中，革兰阴性杆菌的分离频率更高。抗酸剂 - H2受体阻滞剂组的死亡率比硫糖铝组高1.6倍（95%置信区间，0.99至2.50；P = 0.07）。尽管根据意向性分析时我们的结果略未达到统计学显著性，但它们表明，通过促进革兰阴性杆菌在胃内定植，升高胃内pH值的药物会增加接受机械通气患者发生医院获得性肺炎的风险。我们得出结论，在接受机械通气的患者中，使用一种预防性药物来预防应激性溃疡出血，同时保留天然胃酸屏障以防止细菌过度生长，可能比使用抗酸剂和H2受体阻滞剂更可取。
