半坐卧位预防呼吸机相关性肺炎的临床实验研究

Study of the semirecumbent position prevention of ventilator-associated pneumonia

目的 确定RICU机械通气病人半坐卧位可减少误吸。方法 对 2 0例RICU机械通气病人随机取水平仰卧位或半坐卧位 ,间隔 2天交换 2种体位做自我对照实验 ,用Tc 99m硫胶体标记病人胃内容物 ,5h内每隔 30min测定气管、支气管内分泌物的放射计数。结果 病人在仰卧位和半坐卧位护理时 ,支气管内分泌物 5h的总放射计数均数分别是 416 9± 195 7cpm和 972± 2 11cpm(P <0 0 5 ) ;仰卧位 30min和 30 0min的放射计数分别是 30 1± 15 3cpm和 2 6 0 1± 190 4cpm(P <0 0 5 ) ;半坐卧位 30min和 30 0min的放射计数分别是 110± 44cpm和 2 17±6 1cpm (P <0 0 5 )。病人胃液、咽拭子和支气管内分泌同种细菌检出率 ,半坐卧位为 35 %,仰卧位达 70 %。结论 RICU病人持续水平仰卧位护理是胃内容物返流后误吸入气道的潜在高危因素。

Objective: To determine whether the semirecumbent position (45-degree angle ) decreases aspiration of gastric contents to the airways in intubated and mechanically ventilated patients. Methods: Twenty patients requiring intubation and mechanical ventilation in respiratory intensive care unit were given a randomized, two-period crossover trial. The patients were studied in the supine and semirecumbent positions in two separate days. After technetium(Tc)-99 m sulphur colloid labeling of gastric contents, sequential radioactive counts in endobronchial secretions were measured at 30-minute intervals over a 5-hour period. Results:Mean radioactive counts in endobronchial secretions in samples obtained when patients were in the supine position were higher than those in the semirecumbent position (4169±1957 cpm and 972±211 cpm;P<0.05); Moreover, the aspiration pattern for each position was time-dependent: for the supine position, radioactivity was 301±153 cpm at 30 min and 2601±1904 cpm at 300 min (P<0.05); for the semirecumbent position, radioactivity was 110±44 cpm at 30 min and 217±61 cpm at 300 min (P<0.05). The same microorganisms were isolated from stomach, pharynx, and endobronchial samples in 35% of studies done while patients were semirecumbent but in 70% of studies done while patients were in the supine position. Conclusion: The supine position and the length of time in this position are potential risk factors for aspiration of gastric contents.