The Incidence and Immediate Respiratory Consequences of Pulmonary Aspiration of Enteral Feed as Detected Using a Modified Glucose Oxidase Test

Pulmonary micro-aspiration of enteral feed in intubated critically ill patients has been reported to occur commonly. In this prospective observational study the incidence of micro-aspiration, diagnosed by a modified glucose oxidase test, is reported in 25 enterally fed critically ill and tracheally intubated patients on a general intensive care unit. Episodes of microaspiration were correlated with changes in PaO 2 /FiO 2 ratio as an index of changes in degree of lung injury. The modified glucose oxidase test differs from the traditional glucose oxidase test because of the enrichment of the feed with glucose (10g glucose added to 500 ml enteral feed resulting in a tenfold increase in glucose concentration). Pulmonary aspiration of feed was detected by exposing a glucose oxidase strip to tracheal secretions. The feed was enriched with glucose to improve the ability of the reagent strip to detect the feed. The incidence of aspiration of feed was 44% with a prevalence of 6.9% per day of intubation. Only 43% of these episodes of aspiration were detected by the feed being seen in the tracheal secretions. Aspiration was associated with a mean fall in the PaO 2 /FiO 2 ratio of 5.6 kPa from 27.1 kPa to 21.5 kPa (P=0.002). Aspiration of enteral feed is common and causes a demonstrable morbidity. Detection using this simple bedside test may alert the clinician to institute measures to minimize further aspiration.

据报道，在气管插管的重症患者中，肠内营养物的微量误吸很常见。在这项前瞻性观察研究中，报告了在一个综合重症监护病房的25例接受肠内营养且气管插管的重症患者中，通过改良葡萄糖氧化酶试验诊断出的微量误吸发生率。微量误吸事件与作为肺损伤程度变化指标的动脉血氧分压/吸入氧分数值（PaO₂/FiO₂）的变化相关。改良的葡萄糖氧化酶试验不同于传统的葡萄糖氧化酶试验，因为在肠内营养物中添加了葡萄糖（在500毫升肠内营养物中加入10克葡萄糖，导致葡萄糖浓度增加十倍）。通过将葡萄糖氧化酶试纸暴露于气管分泌物中来检测营养物的误吸。在营养物中添加葡萄糖是为了提高试剂试纸检测营养物的能力。营养物误吸的发生率为44%，插管每天的患病率为6.9%。在这些误吸事件中，只有43%是通过在气管分泌物中看到营养物而被检测到的。误吸与PaO₂/FiO₂比值从27.1 kPa降至21.5 kPa平均下降5.6 kPa相关（P = 0.002）。肠内营养物误吸很常见，并会导致明显的发病率。使用这种简单的床边试验进行检测可能会提醒临床医生采取措施以尽量减少进一步的误吸。